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go/src/runtime/asm_amd64.s

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// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
#include "go_asm.h"
#include "go_tls.h"
#include "funcdata.h"
#include "textflag.h"
TEXT runtime·rt0_go(SB),NOSPLIT,$0
// copy arguments forward on an even stack
MOVQ DI, AX // argc
MOVQ SI, BX // argv
SUBQ $(4*8+7), SP // 2args 2auto
ANDQ $~15, SP
MOVQ AX, 16(SP)
MOVQ BX, 24(SP)
// create istack out of the given (operating system) stack.
// _cgo_init may update stackguard.
MOVQ $runtime·g0(SB), DI
LEAQ (-64*1024+104)(SP), BX
MOVQ BX, g_stackguard0(DI)
MOVQ BX, g_stackguard1(DI)
MOVQ BX, (g_stack+stack_lo)(DI)
MOVQ SP, (g_stack+stack_hi)(DI)
// find out information about the processor we're on
MOVQ $0, AX
CPUID
CMPQ AX, $0
JE nocpuinfo
// Figure out how to serialize RDTSC.
// On Intel processors LFENCE is enough. AMD requires MFENCE.
// Don't know about the rest, so let's do MFENCE.
CMPL BX, $0x756E6547 // "Genu"
JNE notintel
CMPL DX, $0x49656E69 // "ineI"
JNE notintel
CMPL CX, $0x6C65746E // "ntel"
JNE notintel
MOVB $1, runtime·lfenceBeforeRdtsc(SB)
notintel:
MOVQ $1, AX
CPUID
MOVL CX, runtime·cpuid_ecx(SB)
MOVL DX, runtime·cpuid_edx(SB)
nocpuinfo:
// if there is an _cgo_init, call it.
MOVQ _cgo_init(SB), AX
TESTQ AX, AX
JZ needtls
// g0 already in DI
MOVQ DI, CX // Win64 uses CX for first parameter
2014-06-26 09:54:39 -06:00
MOVQ $setg_gcc<>(SB), SI
CALL AX
// update stackguard after _cgo_init
MOVQ $runtime·g0(SB), CX
MOVQ (g_stack+stack_lo)(CX), AX
ADDQ $const__StackGuard, AX
MOVQ AX, g_stackguard0(CX)
MOVQ AX, g_stackguard1(CX)
CMPL runtime·iswindows(SB), $0
JEQ ok
needtls:
// skip TLS setup on Plan 9
CMPL runtime·isplan9(SB), $1
JEQ ok
// skip TLS setup on Solaris
CMPL runtime·issolaris(SB), $1
JEQ ok
LEAQ runtime·tls0(SB), DI
CALL runtime·settls(SB)
// store through it, to make sure it works
get_tls(BX)
MOVQ $0x123, g(BX)
MOVQ runtime·tls0(SB), AX
CMPQ AX, $0x123
JEQ 2(PC)
MOVL AX, 0 // abort
ok:
// set the per-goroutine and per-mach "registers"
get_tls(BX)
LEAQ runtime·g0(SB), CX
MOVQ CX, g(BX)
LEAQ runtime·m0(SB), AX
// save m->g0 = g0
MOVQ CX, m_g0(AX)
2014-06-26 09:54:39 -06:00
// save m0 to g0->m
MOVQ AX, g_m(CX)
CLD // convention is D is always left cleared
CALL runtime·check(SB)
MOVL 16(SP), AX // copy argc
MOVL AX, 0(SP)
MOVQ 24(SP), AX // copy argv
MOVQ AX, 8(SP)
CALL runtime·args(SB)
CALL runtime·osinit(SB)
CALL runtime·schedinit(SB)
// create a new goroutine to start program
MOVQ $runtime·mainPC(SB), AX // entry
PUSHQ AX
PUSHQ $0 // arg size
CALL runtime·newproc(SB)
POPQ AX
POPQ AX
// start this M
CALL runtime·mstart(SB)
MOVL $0xf1, 0xf1 // crash
RET
DATA runtime·mainPC+0(SB)/8,$runtime·main(SB)
GLOBL runtime·mainPC(SB),RODATA,$8
TEXT runtime·breakpoint(SB),NOSPLIT,$0-0
BYTE $0xcc
RET
TEXT runtime·asminit(SB),NOSPLIT,$0-0
// No per-thread init.
RET
/*
* go-routine
*/
runtime: scheduler, cgo reorganization * Change use of m->g0 stack (aka scheduler stack). * Provide runtime.mcall(f) to invoke f() on m->g0 stack. * Replace scheduler loop entry with runtime.mcall(schedule). Runtime.mcall eliminates the need for fake scheduler states that exist just to run a bit of code on the m->g0 stack (Grecovery, Gstackalloc). The elimination of the scheduler as a loop that stops and starts using gosave and gogo fixes a bad interaction with the way cgo uses the m->g0 stack. Cgo runs external (gcc-compiled) C functions on that stack, and then when calling back into Go, it sets m->g0->sched.sp below the added call frames, so that other uses of m->g0's stack will not interfere with those frames. Unfortunately, gogo (longjmp) back to the scheduler loop at this point would end up running scheduler with the lower sp, which no longer points at a valid stack frame for a call to scheduler. If scheduler then wrote any function call arguments or local variables to where it expected the stack frame to be, it would overwrite other data on the stack. I realized this possibility while debugging a problem with calling complex Go code in a Go -> C -> Go cgo callback. This wasn't the bug I was looking for, it turns out, but I believe it is a real bug nonetheless. Switching to runtime.mcall, which only adds new frames to the stack and never jumps into functions running in existing ones, fixes this bug. * Move cgo-related code out of proc.c into cgocall.c. * Add very large comment describing cgo call sequences. * Simpilify, regularize cgo function implementations and names. * Add test suite as misc/cgo/test. Now the Go -> C path calls cgocall, which calls asmcgocall, and the C -> Go path calls cgocallback, which calls cgocallbackg. The shuffling, which affects mainly the callback case, moves most of the callback implementation to cgocallback running on the m->curg stack (not the m->g0 scheduler stack) and only while accounted for with $GOMAXPROCS (between calls to exitsyscall and entersyscall). The previous callback code did not block in startcgocallback's approximation to exitsyscall, so if, say, the garbage collector were running, it would still barge in and start doing things like call malloc. Similarly endcgocallback's approximation of entersyscall did not call matchmg to kick off new OS threads when necessary, which caused the bug in issue 1560. Fixes #1560. R=iant CC=golang-dev https://golang.org/cl/4253054
2011-03-07 08:37:42 -07:00
// void gosave(Gobuf*)
// save state in Gobuf; setjmp
TEXT runtime·gosave(SB), NOSPLIT, $0-8
cmd/cc, runtime: convert C compilers to use Go calling convention To date, the C compilers and Go compilers differed only in how values were returned from functions. This made it difficult to call Go from C or C from Go if return values were involved. It also made assembly called from Go and assembly called from C different. This CL changes the C compiler to use the Go conventions, passing results on the stack, after the arguments. [Exception: this does not apply to C ... functions, because you can't know where on the stack the arguments end.] By doing this, the CL makes it possible to rewrite C functions into Go one at a time, without worrying about which languages call that function or which languages it calls. This CL also updates all the assembly files in package runtime to use the new conventions. Argument references of the form 40(SP) have been rewritten to the form name+10(FP) instead, and there are now Go func prototypes for every assembly function called from C or Go. This means that 'go vet runtime' checks effectively every assembly function, and go vet's output was used to automate the bulk of the conversion. Some functions, like seek and nsec on Plan 9, needed to be rewritten. Many assembly routines called from C were reading arguments incorrectly, using MOVL instead of MOVQ or vice versa, especially on the less used systems like openbsd. These were found by go vet and have been corrected too. If we're lucky, this may reduce flakiness on those systems. Tested on: darwin/386 darwin/amd64 linux/arm linux/386 linux/amd64 If this breaks another system, the bug is almost certainly in the sys_$GOOS_$GOARCH.s file, since the rest of the CL is tested by the combination of the above systems. LGTM=dvyukov, iant R=golang-codereviews, 0intro, dave, alex.brainman, dvyukov, iant CC=golang-codereviews, josharian, r https://golang.org/cl/135830043
2014-08-27 09:32:17 -06:00
MOVQ buf+0(FP), AX // gobuf
LEAQ buf+0(FP), BX // caller's SP
MOVQ BX, gobuf_sp(AX)
MOVQ 0(SP), BX // caller's PC
MOVQ BX, gobuf_pc(AX)
MOVQ $0, gobuf_ret(AX)
MOVQ $0, gobuf_ctxt(AX)
MOVQ BP, gobuf_bp(AX)
get_tls(CX)
MOVQ g(CX), BX
MOVQ BX, gobuf_g(AX)
RET
// void gogo(Gobuf*)
// restore state from Gobuf; longjmp
TEXT runtime·gogo(SB), NOSPLIT, $0-8
cmd/cc, runtime: convert C compilers to use Go calling convention To date, the C compilers and Go compilers differed only in how values were returned from functions. This made it difficult to call Go from C or C from Go if return values were involved. It also made assembly called from Go and assembly called from C different. This CL changes the C compiler to use the Go conventions, passing results on the stack, after the arguments. [Exception: this does not apply to C ... functions, because you can't know where on the stack the arguments end.] By doing this, the CL makes it possible to rewrite C functions into Go one at a time, without worrying about which languages call that function or which languages it calls. This CL also updates all the assembly files in package runtime to use the new conventions. Argument references of the form 40(SP) have been rewritten to the form name+10(FP) instead, and there are now Go func prototypes for every assembly function called from C or Go. This means that 'go vet runtime' checks effectively every assembly function, and go vet's output was used to automate the bulk of the conversion. Some functions, like seek and nsec on Plan 9, needed to be rewritten. Many assembly routines called from C were reading arguments incorrectly, using MOVL instead of MOVQ or vice versa, especially on the less used systems like openbsd. These were found by go vet and have been corrected too. If we're lucky, this may reduce flakiness on those systems. Tested on: darwin/386 darwin/amd64 linux/arm linux/386 linux/amd64 If this breaks another system, the bug is almost certainly in the sys_$GOOS_$GOARCH.s file, since the rest of the CL is tested by the combination of the above systems. LGTM=dvyukov, iant R=golang-codereviews, 0intro, dave, alex.brainman, dvyukov, iant CC=golang-codereviews, josharian, r https://golang.org/cl/135830043
2014-08-27 09:32:17 -06:00
MOVQ buf+0(FP), BX // gobuf
MOVQ gobuf_g(BX), DX
MOVQ 0(DX), CX // make sure g != nil
get_tls(CX)
MOVQ DX, g(CX)
MOVQ gobuf_sp(BX), SP // restore SP
MOVQ gobuf_ret(BX), AX
MOVQ gobuf_ctxt(BX), DX
MOVQ gobuf_bp(BX), BP
MOVQ $0, gobuf_sp(BX) // clear to help garbage collector
MOVQ $0, gobuf_ret(BX)
MOVQ $0, gobuf_ctxt(BX)
MOVQ $0, gobuf_bp(BX)
MOVQ gobuf_pc(BX), BX
JMP BX
// func mcall(fn func(*g))
runtime: scheduler, cgo reorganization * Change use of m->g0 stack (aka scheduler stack). * Provide runtime.mcall(f) to invoke f() on m->g0 stack. * Replace scheduler loop entry with runtime.mcall(schedule). Runtime.mcall eliminates the need for fake scheduler states that exist just to run a bit of code on the m->g0 stack (Grecovery, Gstackalloc). The elimination of the scheduler as a loop that stops and starts using gosave and gogo fixes a bad interaction with the way cgo uses the m->g0 stack. Cgo runs external (gcc-compiled) C functions on that stack, and then when calling back into Go, it sets m->g0->sched.sp below the added call frames, so that other uses of m->g0's stack will not interfere with those frames. Unfortunately, gogo (longjmp) back to the scheduler loop at this point would end up running scheduler with the lower sp, which no longer points at a valid stack frame for a call to scheduler. If scheduler then wrote any function call arguments or local variables to where it expected the stack frame to be, it would overwrite other data on the stack. I realized this possibility while debugging a problem with calling complex Go code in a Go -> C -> Go cgo callback. This wasn't the bug I was looking for, it turns out, but I believe it is a real bug nonetheless. Switching to runtime.mcall, which only adds new frames to the stack and never jumps into functions running in existing ones, fixes this bug. * Move cgo-related code out of proc.c into cgocall.c. * Add very large comment describing cgo call sequences. * Simpilify, regularize cgo function implementations and names. * Add test suite as misc/cgo/test. Now the Go -> C path calls cgocall, which calls asmcgocall, and the C -> Go path calls cgocallback, which calls cgocallbackg. The shuffling, which affects mainly the callback case, moves most of the callback implementation to cgocallback running on the m->curg stack (not the m->g0 scheduler stack) and only while accounted for with $GOMAXPROCS (between calls to exitsyscall and entersyscall). The previous callback code did not block in startcgocallback's approximation to exitsyscall, so if, say, the garbage collector were running, it would still barge in and start doing things like call malloc. Similarly endcgocallback's approximation of entersyscall did not call matchmg to kick off new OS threads when necessary, which caused the bug in issue 1560. Fixes #1560. R=iant CC=golang-dev https://golang.org/cl/4253054
2011-03-07 08:37:42 -07:00
// Switch to m->g0's stack, call fn(g).
runtime: stack split + garbage collection bug The g->sched.sp saved stack pointer and the g->stackbase and g->stackguard stack bounds can change even while "the world is stopped", because a goroutine has to call functions (and therefore might split its stack) when exiting a system call to check whether the world is stopped (and if so, wait until the world continues). That means the garbage collector cannot access those values safely (without a race) for goroutines executing system calls. Instead, save a consistent triple in g->gcsp, g->gcstack, g->gcguard during entersyscall and have the garbage collector refer to those. The old code was occasionally seeing (because of the race) an sp and stk that did not correspond to each other, so that stk - sp was not the number of stack bytes following sp. In that case, if sp < stk then the call scanblock(sp, stk - sp) scanned too many bytes (anything between the two pointers, which pointed into different allocation blocks). If sp > stk then stk - sp wrapped around. On 32-bit, stk - sp is a uintptr (uint32) converted to int64 in the call to scanblock, so a large (~4G) but positive number. Scanblock would try to scan that many bytes and eventually fault accessing unmapped memory. On 64-bit, stk - sp is a uintptr (uint64) promoted to int64 in the call to scanblock, so a negative number. Scanblock would not scan anything, possibly causing in-use blocks to be freed. In short, 32-bit platforms would have seen either ineffective garbage collection or crashes during garbage collection, while 64-bit platforms would have seen either ineffective or incorrect garbage collection. You can see the invalid arguments to scanblock in the stack traces in issue 1620. Fixes #1620. Fixes #1746. R=iant, r CC=golang-dev https://golang.org/cl/4437075
2011-04-27 21:21:12 -06:00
// Fn must never return. It should gogo(&g->sched)
runtime: scheduler, cgo reorganization * Change use of m->g0 stack (aka scheduler stack). * Provide runtime.mcall(f) to invoke f() on m->g0 stack. * Replace scheduler loop entry with runtime.mcall(schedule). Runtime.mcall eliminates the need for fake scheduler states that exist just to run a bit of code on the m->g0 stack (Grecovery, Gstackalloc). The elimination of the scheduler as a loop that stops and starts using gosave and gogo fixes a bad interaction with the way cgo uses the m->g0 stack. Cgo runs external (gcc-compiled) C functions on that stack, and then when calling back into Go, it sets m->g0->sched.sp below the added call frames, so that other uses of m->g0's stack will not interfere with those frames. Unfortunately, gogo (longjmp) back to the scheduler loop at this point would end up running scheduler with the lower sp, which no longer points at a valid stack frame for a call to scheduler. If scheduler then wrote any function call arguments or local variables to where it expected the stack frame to be, it would overwrite other data on the stack. I realized this possibility while debugging a problem with calling complex Go code in a Go -> C -> Go cgo callback. This wasn't the bug I was looking for, it turns out, but I believe it is a real bug nonetheless. Switching to runtime.mcall, which only adds new frames to the stack and never jumps into functions running in existing ones, fixes this bug. * Move cgo-related code out of proc.c into cgocall.c. * Add very large comment describing cgo call sequences. * Simpilify, regularize cgo function implementations and names. * Add test suite as misc/cgo/test. Now the Go -> C path calls cgocall, which calls asmcgocall, and the C -> Go path calls cgocallback, which calls cgocallbackg. The shuffling, which affects mainly the callback case, moves most of the callback implementation to cgocallback running on the m->curg stack (not the m->g0 scheduler stack) and only while accounted for with $GOMAXPROCS (between calls to exitsyscall and entersyscall). The previous callback code did not block in startcgocallback's approximation to exitsyscall, so if, say, the garbage collector were running, it would still barge in and start doing things like call malloc. Similarly endcgocallback's approximation of entersyscall did not call matchmg to kick off new OS threads when necessary, which caused the bug in issue 1560. Fixes #1560. R=iant CC=golang-dev https://golang.org/cl/4253054
2011-03-07 08:37:42 -07:00
// to keep running g.
TEXT runtime·mcall(SB), NOSPLIT, $0-8
runtime: scheduler, cgo reorganization * Change use of m->g0 stack (aka scheduler stack). * Provide runtime.mcall(f) to invoke f() on m->g0 stack. * Replace scheduler loop entry with runtime.mcall(schedule). Runtime.mcall eliminates the need for fake scheduler states that exist just to run a bit of code on the m->g0 stack (Grecovery, Gstackalloc). The elimination of the scheduler as a loop that stops and starts using gosave and gogo fixes a bad interaction with the way cgo uses the m->g0 stack. Cgo runs external (gcc-compiled) C functions on that stack, and then when calling back into Go, it sets m->g0->sched.sp below the added call frames, so that other uses of m->g0's stack will not interfere with those frames. Unfortunately, gogo (longjmp) back to the scheduler loop at this point would end up running scheduler with the lower sp, which no longer points at a valid stack frame for a call to scheduler. If scheduler then wrote any function call arguments or local variables to where it expected the stack frame to be, it would overwrite other data on the stack. I realized this possibility while debugging a problem with calling complex Go code in a Go -> C -> Go cgo callback. This wasn't the bug I was looking for, it turns out, but I believe it is a real bug nonetheless. Switching to runtime.mcall, which only adds new frames to the stack and never jumps into functions running in existing ones, fixes this bug. * Move cgo-related code out of proc.c into cgocall.c. * Add very large comment describing cgo call sequences. * Simpilify, regularize cgo function implementations and names. * Add test suite as misc/cgo/test. Now the Go -> C path calls cgocall, which calls asmcgocall, and the C -> Go path calls cgocallback, which calls cgocallbackg. The shuffling, which affects mainly the callback case, moves most of the callback implementation to cgocallback running on the m->curg stack (not the m->g0 scheduler stack) and only while accounted for with $GOMAXPROCS (between calls to exitsyscall and entersyscall). The previous callback code did not block in startcgocallback's approximation to exitsyscall, so if, say, the garbage collector were running, it would still barge in and start doing things like call malloc. Similarly endcgocallback's approximation of entersyscall did not call matchmg to kick off new OS threads when necessary, which caused the bug in issue 1560. Fixes #1560. R=iant CC=golang-dev https://golang.org/cl/4253054
2011-03-07 08:37:42 -07:00
MOVQ fn+0(FP), DI
get_tls(CX)
MOVQ g(CX), AX // save state in g->sched
runtime: scheduler, cgo reorganization * Change use of m->g0 stack (aka scheduler stack). * Provide runtime.mcall(f) to invoke f() on m->g0 stack. * Replace scheduler loop entry with runtime.mcall(schedule). Runtime.mcall eliminates the need for fake scheduler states that exist just to run a bit of code on the m->g0 stack (Grecovery, Gstackalloc). The elimination of the scheduler as a loop that stops and starts using gosave and gogo fixes a bad interaction with the way cgo uses the m->g0 stack. Cgo runs external (gcc-compiled) C functions on that stack, and then when calling back into Go, it sets m->g0->sched.sp below the added call frames, so that other uses of m->g0's stack will not interfere with those frames. Unfortunately, gogo (longjmp) back to the scheduler loop at this point would end up running scheduler with the lower sp, which no longer points at a valid stack frame for a call to scheduler. If scheduler then wrote any function call arguments or local variables to where it expected the stack frame to be, it would overwrite other data on the stack. I realized this possibility while debugging a problem with calling complex Go code in a Go -> C -> Go cgo callback. This wasn't the bug I was looking for, it turns out, but I believe it is a real bug nonetheless. Switching to runtime.mcall, which only adds new frames to the stack and never jumps into functions running in existing ones, fixes this bug. * Move cgo-related code out of proc.c into cgocall.c. * Add very large comment describing cgo call sequences. * Simpilify, regularize cgo function implementations and names. * Add test suite as misc/cgo/test. Now the Go -> C path calls cgocall, which calls asmcgocall, and the C -> Go path calls cgocallback, which calls cgocallbackg. The shuffling, which affects mainly the callback case, moves most of the callback implementation to cgocallback running on the m->curg stack (not the m->g0 scheduler stack) and only while accounted for with $GOMAXPROCS (between calls to exitsyscall and entersyscall). The previous callback code did not block in startcgocallback's approximation to exitsyscall, so if, say, the garbage collector were running, it would still barge in and start doing things like call malloc. Similarly endcgocallback's approximation of entersyscall did not call matchmg to kick off new OS threads when necessary, which caused the bug in issue 1560. Fixes #1560. R=iant CC=golang-dev https://golang.org/cl/4253054
2011-03-07 08:37:42 -07:00
MOVQ 0(SP), BX // caller's PC
MOVQ BX, (g_sched+gobuf_pc)(AX)
cmd/cc, runtime: convert C compilers to use Go calling convention To date, the C compilers and Go compilers differed only in how values were returned from functions. This made it difficult to call Go from C or C from Go if return values were involved. It also made assembly called from Go and assembly called from C different. This CL changes the C compiler to use the Go conventions, passing results on the stack, after the arguments. [Exception: this does not apply to C ... functions, because you can't know where on the stack the arguments end.] By doing this, the CL makes it possible to rewrite C functions into Go one at a time, without worrying about which languages call that function or which languages it calls. This CL also updates all the assembly files in package runtime to use the new conventions. Argument references of the form 40(SP) have been rewritten to the form name+10(FP) instead, and there are now Go func prototypes for every assembly function called from C or Go. This means that 'go vet runtime' checks effectively every assembly function, and go vet's output was used to automate the bulk of the conversion. Some functions, like seek and nsec on Plan 9, needed to be rewritten. Many assembly routines called from C were reading arguments incorrectly, using MOVL instead of MOVQ or vice versa, especially on the less used systems like openbsd. These were found by go vet and have been corrected too. If we're lucky, this may reduce flakiness on those systems. Tested on: darwin/386 darwin/amd64 linux/arm linux/386 linux/amd64 If this breaks another system, the bug is almost certainly in the sys_$GOOS_$GOARCH.s file, since the rest of the CL is tested by the combination of the above systems. LGTM=dvyukov, iant R=golang-codereviews, 0intro, dave, alex.brainman, dvyukov, iant CC=golang-codereviews, josharian, r https://golang.org/cl/135830043
2014-08-27 09:32:17 -06:00
LEAQ fn+0(FP), BX // caller's SP
runtime: scheduler, cgo reorganization * Change use of m->g0 stack (aka scheduler stack). * Provide runtime.mcall(f) to invoke f() on m->g0 stack. * Replace scheduler loop entry with runtime.mcall(schedule). Runtime.mcall eliminates the need for fake scheduler states that exist just to run a bit of code on the m->g0 stack (Grecovery, Gstackalloc). The elimination of the scheduler as a loop that stops and starts using gosave and gogo fixes a bad interaction with the way cgo uses the m->g0 stack. Cgo runs external (gcc-compiled) C functions on that stack, and then when calling back into Go, it sets m->g0->sched.sp below the added call frames, so that other uses of m->g0's stack will not interfere with those frames. Unfortunately, gogo (longjmp) back to the scheduler loop at this point would end up running scheduler with the lower sp, which no longer points at a valid stack frame for a call to scheduler. If scheduler then wrote any function call arguments or local variables to where it expected the stack frame to be, it would overwrite other data on the stack. I realized this possibility while debugging a problem with calling complex Go code in a Go -> C -> Go cgo callback. This wasn't the bug I was looking for, it turns out, but I believe it is a real bug nonetheless. Switching to runtime.mcall, which only adds new frames to the stack and never jumps into functions running in existing ones, fixes this bug. * Move cgo-related code out of proc.c into cgocall.c. * Add very large comment describing cgo call sequences. * Simpilify, regularize cgo function implementations and names. * Add test suite as misc/cgo/test. Now the Go -> C path calls cgocall, which calls asmcgocall, and the C -> Go path calls cgocallback, which calls cgocallbackg. The shuffling, which affects mainly the callback case, moves most of the callback implementation to cgocallback running on the m->curg stack (not the m->g0 scheduler stack) and only while accounted for with $GOMAXPROCS (between calls to exitsyscall and entersyscall). The previous callback code did not block in startcgocallback's approximation to exitsyscall, so if, say, the garbage collector were running, it would still barge in and start doing things like call malloc. Similarly endcgocallback's approximation of entersyscall did not call matchmg to kick off new OS threads when necessary, which caused the bug in issue 1560. Fixes #1560. R=iant CC=golang-dev https://golang.org/cl/4253054
2011-03-07 08:37:42 -07:00
MOVQ BX, (g_sched+gobuf_sp)(AX)
MOVQ AX, (g_sched+gobuf_g)(AX)
MOVQ BP, (g_sched+gobuf_bp)(AX)
runtime: scheduler, cgo reorganization * Change use of m->g0 stack (aka scheduler stack). * Provide runtime.mcall(f) to invoke f() on m->g0 stack. * Replace scheduler loop entry with runtime.mcall(schedule). Runtime.mcall eliminates the need for fake scheduler states that exist just to run a bit of code on the m->g0 stack (Grecovery, Gstackalloc). The elimination of the scheduler as a loop that stops and starts using gosave and gogo fixes a bad interaction with the way cgo uses the m->g0 stack. Cgo runs external (gcc-compiled) C functions on that stack, and then when calling back into Go, it sets m->g0->sched.sp below the added call frames, so that other uses of m->g0's stack will not interfere with those frames. Unfortunately, gogo (longjmp) back to the scheduler loop at this point would end up running scheduler with the lower sp, which no longer points at a valid stack frame for a call to scheduler. If scheduler then wrote any function call arguments or local variables to where it expected the stack frame to be, it would overwrite other data on the stack. I realized this possibility while debugging a problem with calling complex Go code in a Go -> C -> Go cgo callback. This wasn't the bug I was looking for, it turns out, but I believe it is a real bug nonetheless. Switching to runtime.mcall, which only adds new frames to the stack and never jumps into functions running in existing ones, fixes this bug. * Move cgo-related code out of proc.c into cgocall.c. * Add very large comment describing cgo call sequences. * Simpilify, regularize cgo function implementations and names. * Add test suite as misc/cgo/test. Now the Go -> C path calls cgocall, which calls asmcgocall, and the C -> Go path calls cgocallback, which calls cgocallbackg. The shuffling, which affects mainly the callback case, moves most of the callback implementation to cgocallback running on the m->curg stack (not the m->g0 scheduler stack) and only while accounted for with $GOMAXPROCS (between calls to exitsyscall and entersyscall). The previous callback code did not block in startcgocallback's approximation to exitsyscall, so if, say, the garbage collector were running, it would still barge in and start doing things like call malloc. Similarly endcgocallback's approximation of entersyscall did not call matchmg to kick off new OS threads when necessary, which caused the bug in issue 1560. Fixes #1560. R=iant CC=golang-dev https://golang.org/cl/4253054
2011-03-07 08:37:42 -07:00
// switch to m->g0 & its stack, call fn
2014-06-26 09:54:39 -06:00
MOVQ g(CX), BX
MOVQ g_m(BX), BX
runtime: scheduler, cgo reorganization * Change use of m->g0 stack (aka scheduler stack). * Provide runtime.mcall(f) to invoke f() on m->g0 stack. * Replace scheduler loop entry with runtime.mcall(schedule). Runtime.mcall eliminates the need for fake scheduler states that exist just to run a bit of code on the m->g0 stack (Grecovery, Gstackalloc). The elimination of the scheduler as a loop that stops and starts using gosave and gogo fixes a bad interaction with the way cgo uses the m->g0 stack. Cgo runs external (gcc-compiled) C functions on that stack, and then when calling back into Go, it sets m->g0->sched.sp below the added call frames, so that other uses of m->g0's stack will not interfere with those frames. Unfortunately, gogo (longjmp) back to the scheduler loop at this point would end up running scheduler with the lower sp, which no longer points at a valid stack frame for a call to scheduler. If scheduler then wrote any function call arguments or local variables to where it expected the stack frame to be, it would overwrite other data on the stack. I realized this possibility while debugging a problem with calling complex Go code in a Go -> C -> Go cgo callback. This wasn't the bug I was looking for, it turns out, but I believe it is a real bug nonetheless. Switching to runtime.mcall, which only adds new frames to the stack and never jumps into functions running in existing ones, fixes this bug. * Move cgo-related code out of proc.c into cgocall.c. * Add very large comment describing cgo call sequences. * Simpilify, regularize cgo function implementations and names. * Add test suite as misc/cgo/test. Now the Go -> C path calls cgocall, which calls asmcgocall, and the C -> Go path calls cgocallback, which calls cgocallbackg. The shuffling, which affects mainly the callback case, moves most of the callback implementation to cgocallback running on the m->curg stack (not the m->g0 scheduler stack) and only while accounted for with $GOMAXPROCS (between calls to exitsyscall and entersyscall). The previous callback code did not block in startcgocallback's approximation to exitsyscall, so if, say, the garbage collector were running, it would still barge in and start doing things like call malloc. Similarly endcgocallback's approximation of entersyscall did not call matchmg to kick off new OS threads when necessary, which caused the bug in issue 1560. Fixes #1560. R=iant CC=golang-dev https://golang.org/cl/4253054
2011-03-07 08:37:42 -07:00
MOVQ m_g0(BX), SI
CMPQ SI, AX // if g == m->g0 call badmcall
JNE 3(PC)
MOVQ $runtime·badmcall(SB), AX
JMP AX
runtime: scheduler, cgo reorganization * Change use of m->g0 stack (aka scheduler stack). * Provide runtime.mcall(f) to invoke f() on m->g0 stack. * Replace scheduler loop entry with runtime.mcall(schedule). Runtime.mcall eliminates the need for fake scheduler states that exist just to run a bit of code on the m->g0 stack (Grecovery, Gstackalloc). The elimination of the scheduler as a loop that stops and starts using gosave and gogo fixes a bad interaction with the way cgo uses the m->g0 stack. Cgo runs external (gcc-compiled) C functions on that stack, and then when calling back into Go, it sets m->g0->sched.sp below the added call frames, so that other uses of m->g0's stack will not interfere with those frames. Unfortunately, gogo (longjmp) back to the scheduler loop at this point would end up running scheduler with the lower sp, which no longer points at a valid stack frame for a call to scheduler. If scheduler then wrote any function call arguments or local variables to where it expected the stack frame to be, it would overwrite other data on the stack. I realized this possibility while debugging a problem with calling complex Go code in a Go -> C -> Go cgo callback. This wasn't the bug I was looking for, it turns out, but I believe it is a real bug nonetheless. Switching to runtime.mcall, which only adds new frames to the stack and never jumps into functions running in existing ones, fixes this bug. * Move cgo-related code out of proc.c into cgocall.c. * Add very large comment describing cgo call sequences. * Simpilify, regularize cgo function implementations and names. * Add test suite as misc/cgo/test. Now the Go -> C path calls cgocall, which calls asmcgocall, and the C -> Go path calls cgocallback, which calls cgocallbackg. The shuffling, which affects mainly the callback case, moves most of the callback implementation to cgocallback running on the m->curg stack (not the m->g0 scheduler stack) and only while accounted for with $GOMAXPROCS (between calls to exitsyscall and entersyscall). The previous callback code did not block in startcgocallback's approximation to exitsyscall, so if, say, the garbage collector were running, it would still barge in and start doing things like call malloc. Similarly endcgocallback's approximation of entersyscall did not call matchmg to kick off new OS threads when necessary, which caused the bug in issue 1560. Fixes #1560. R=iant CC=golang-dev https://golang.org/cl/4253054
2011-03-07 08:37:42 -07:00
MOVQ SI, g(CX) // g = m->g0
MOVQ (g_sched+gobuf_sp)(SI), SP // sp = m->g0->sched.sp
runtime: scheduler, cgo reorganization * Change use of m->g0 stack (aka scheduler stack). * Provide runtime.mcall(f) to invoke f() on m->g0 stack. * Replace scheduler loop entry with runtime.mcall(schedule). Runtime.mcall eliminates the need for fake scheduler states that exist just to run a bit of code on the m->g0 stack (Grecovery, Gstackalloc). The elimination of the scheduler as a loop that stops and starts using gosave and gogo fixes a bad interaction with the way cgo uses the m->g0 stack. Cgo runs external (gcc-compiled) C functions on that stack, and then when calling back into Go, it sets m->g0->sched.sp below the added call frames, so that other uses of m->g0's stack will not interfere with those frames. Unfortunately, gogo (longjmp) back to the scheduler loop at this point would end up running scheduler with the lower sp, which no longer points at a valid stack frame for a call to scheduler. If scheduler then wrote any function call arguments or local variables to where it expected the stack frame to be, it would overwrite other data on the stack. I realized this possibility while debugging a problem with calling complex Go code in a Go -> C -> Go cgo callback. This wasn't the bug I was looking for, it turns out, but I believe it is a real bug nonetheless. Switching to runtime.mcall, which only adds new frames to the stack and never jumps into functions running in existing ones, fixes this bug. * Move cgo-related code out of proc.c into cgocall.c. * Add very large comment describing cgo call sequences. * Simpilify, regularize cgo function implementations and names. * Add test suite as misc/cgo/test. Now the Go -> C path calls cgocall, which calls asmcgocall, and the C -> Go path calls cgocallback, which calls cgocallbackg. The shuffling, which affects mainly the callback case, moves most of the callback implementation to cgocallback running on the m->curg stack (not the m->g0 scheduler stack) and only while accounted for with $GOMAXPROCS (between calls to exitsyscall and entersyscall). The previous callback code did not block in startcgocallback's approximation to exitsyscall, so if, say, the garbage collector were running, it would still barge in and start doing things like call malloc. Similarly endcgocallback's approximation of entersyscall did not call matchmg to kick off new OS threads when necessary, which caused the bug in issue 1560. Fixes #1560. R=iant CC=golang-dev https://golang.org/cl/4253054
2011-03-07 08:37:42 -07:00
PUSHQ AX
MOVQ DI, DX
MOVQ 0(DI), DI
runtime: scheduler, cgo reorganization * Change use of m->g0 stack (aka scheduler stack). * Provide runtime.mcall(f) to invoke f() on m->g0 stack. * Replace scheduler loop entry with runtime.mcall(schedule). Runtime.mcall eliminates the need for fake scheduler states that exist just to run a bit of code on the m->g0 stack (Grecovery, Gstackalloc). The elimination of the scheduler as a loop that stops and starts using gosave and gogo fixes a bad interaction with the way cgo uses the m->g0 stack. Cgo runs external (gcc-compiled) C functions on that stack, and then when calling back into Go, it sets m->g0->sched.sp below the added call frames, so that other uses of m->g0's stack will not interfere with those frames. Unfortunately, gogo (longjmp) back to the scheduler loop at this point would end up running scheduler with the lower sp, which no longer points at a valid stack frame for a call to scheduler. If scheduler then wrote any function call arguments or local variables to where it expected the stack frame to be, it would overwrite other data on the stack. I realized this possibility while debugging a problem with calling complex Go code in a Go -> C -> Go cgo callback. This wasn't the bug I was looking for, it turns out, but I believe it is a real bug nonetheless. Switching to runtime.mcall, which only adds new frames to the stack and never jumps into functions running in existing ones, fixes this bug. * Move cgo-related code out of proc.c into cgocall.c. * Add very large comment describing cgo call sequences. * Simpilify, regularize cgo function implementations and names. * Add test suite as misc/cgo/test. Now the Go -> C path calls cgocall, which calls asmcgocall, and the C -> Go path calls cgocallback, which calls cgocallbackg. The shuffling, which affects mainly the callback case, moves most of the callback implementation to cgocallback running on the m->curg stack (not the m->g0 scheduler stack) and only while accounted for with $GOMAXPROCS (between calls to exitsyscall and entersyscall). The previous callback code did not block in startcgocallback's approximation to exitsyscall, so if, say, the garbage collector were running, it would still barge in and start doing things like call malloc. Similarly endcgocallback's approximation of entersyscall did not call matchmg to kick off new OS threads when necessary, which caused the bug in issue 1560. Fixes #1560. R=iant CC=golang-dev https://golang.org/cl/4253054
2011-03-07 08:37:42 -07:00
CALL DI
POPQ AX
MOVQ $runtime·badmcall2(SB), AX
JMP AX
runtime: scheduler, cgo reorganization * Change use of m->g0 stack (aka scheduler stack). * Provide runtime.mcall(f) to invoke f() on m->g0 stack. * Replace scheduler loop entry with runtime.mcall(schedule). Runtime.mcall eliminates the need for fake scheduler states that exist just to run a bit of code on the m->g0 stack (Grecovery, Gstackalloc). The elimination of the scheduler as a loop that stops and starts using gosave and gogo fixes a bad interaction with the way cgo uses the m->g0 stack. Cgo runs external (gcc-compiled) C functions on that stack, and then when calling back into Go, it sets m->g0->sched.sp below the added call frames, so that other uses of m->g0's stack will not interfere with those frames. Unfortunately, gogo (longjmp) back to the scheduler loop at this point would end up running scheduler with the lower sp, which no longer points at a valid stack frame for a call to scheduler. If scheduler then wrote any function call arguments or local variables to where it expected the stack frame to be, it would overwrite other data on the stack. I realized this possibility while debugging a problem with calling complex Go code in a Go -> C -> Go cgo callback. This wasn't the bug I was looking for, it turns out, but I believe it is a real bug nonetheless. Switching to runtime.mcall, which only adds new frames to the stack and never jumps into functions running in existing ones, fixes this bug. * Move cgo-related code out of proc.c into cgocall.c. * Add very large comment describing cgo call sequences. * Simpilify, regularize cgo function implementations and names. * Add test suite as misc/cgo/test. Now the Go -> C path calls cgocall, which calls asmcgocall, and the C -> Go path calls cgocallback, which calls cgocallbackg. The shuffling, which affects mainly the callback case, moves most of the callback implementation to cgocallback running on the m->curg stack (not the m->g0 scheduler stack) and only while accounted for with $GOMAXPROCS (between calls to exitsyscall and entersyscall). The previous callback code did not block in startcgocallback's approximation to exitsyscall, so if, say, the garbage collector were running, it would still barge in and start doing things like call malloc. Similarly endcgocallback's approximation of entersyscall did not call matchmg to kick off new OS threads when necessary, which caused the bug in issue 1560. Fixes #1560. R=iant CC=golang-dev https://golang.org/cl/4253054
2011-03-07 08:37:42 -07:00
RET
[dev.cc] runtime: delete scalararg, ptrarg; rename onM to systemstack Scalararg and ptrarg are not "signal safe". Go code filling them out can be interrupted by a signal, and then the signal handler runs, and if it also ends up in Go code that uses scalararg or ptrarg, now the old values have been smashed. For the pieces of code that do need to run in a signal handler, we introduced onM_signalok, which is really just onM except that the _signalok is meant to convey that the caller asserts that scalarg and ptrarg will be restored to their old values after the call (instead of the usual behavior, zeroing them). Scalararg and ptrarg are also untyped and therefore error-prone. Go code can always pass a closure instead of using scalararg and ptrarg; they were only really necessary for C code. And there's no more C code. For all these reasons, delete scalararg and ptrarg, converting the few remaining references to use closures. Once those are gone, there is no need for a distinction between onM and onM_signalok, so replace both with a single function equivalent to the current onM_signalok (that is, it can be called on any of the curg, g0, and gsignal stacks). The name onM and the phrase 'm stack' are misnomers, because on most system an M has two system stacks: the main thread stack and the signal handling stack. Correct the misnomer by naming the replacement function systemstack. Fix a few references to "M stack" in code. The main motivation for this change is to eliminate scalararg/ptrarg. Rick and I have already seen them cause problems because the calling sequence m.ptrarg[0] = p is a heap pointer assignment, so it gets a write barrier. The write barrier also uses onM, so it has all the same problems as if it were being invoked by a signal handler. We worked around this by saving and restoring the old values and by calling onM_signalok, but there's no point in keeping this nice home for bugs around any longer. This CL also changes funcline to return the file name as a result instead of filling in a passed-in *string. (The *string signature is left over from when the code was written in and called from C.) That's arguably an unrelated change, except that once I had done the ptrarg/scalararg/onM cleanup I started getting false positives about the *string argument escaping (not allowed in package runtime). The compiler is wrong, but the easiest fix is to write the code like Go code instead of like C code. I am a bit worried that the compiler is wrong because of some use of uninitialized memory in the escape analysis. If that's the reason, it will go away when we convert the compiler to Go. (And if not, we'll debug it the next time.) LGTM=khr R=r, khr CC=austin, golang-codereviews, iant, rlh https://golang.org/cl/174950043
2014-11-12 12:54:31 -07:00
// systemstack_switch is a dummy routine that systemstack leaves at the bottom
// of the G stack. We need to distinguish the routine that
// lives at the bottom of the G stack from the one that lives
[dev.cc] runtime: delete scalararg, ptrarg; rename onM to systemstack Scalararg and ptrarg are not "signal safe". Go code filling them out can be interrupted by a signal, and then the signal handler runs, and if it also ends up in Go code that uses scalararg or ptrarg, now the old values have been smashed. For the pieces of code that do need to run in a signal handler, we introduced onM_signalok, which is really just onM except that the _signalok is meant to convey that the caller asserts that scalarg and ptrarg will be restored to their old values after the call (instead of the usual behavior, zeroing them). Scalararg and ptrarg are also untyped and therefore error-prone. Go code can always pass a closure instead of using scalararg and ptrarg; they were only really necessary for C code. And there's no more C code. For all these reasons, delete scalararg and ptrarg, converting the few remaining references to use closures. Once those are gone, there is no need for a distinction between onM and onM_signalok, so replace both with a single function equivalent to the current onM_signalok (that is, it can be called on any of the curg, g0, and gsignal stacks). The name onM and the phrase 'm stack' are misnomers, because on most system an M has two system stacks: the main thread stack and the signal handling stack. Correct the misnomer by naming the replacement function systemstack. Fix a few references to "M stack" in code. The main motivation for this change is to eliminate scalararg/ptrarg. Rick and I have already seen them cause problems because the calling sequence m.ptrarg[0] = p is a heap pointer assignment, so it gets a write barrier. The write barrier also uses onM, so it has all the same problems as if it were being invoked by a signal handler. We worked around this by saving and restoring the old values and by calling onM_signalok, but there's no point in keeping this nice home for bugs around any longer. This CL also changes funcline to return the file name as a result instead of filling in a passed-in *string. (The *string signature is left over from when the code was written in and called from C.) That's arguably an unrelated change, except that once I had done the ptrarg/scalararg/onM cleanup I started getting false positives about the *string argument escaping (not allowed in package runtime). The compiler is wrong, but the easiest fix is to write the code like Go code instead of like C code. I am a bit worried that the compiler is wrong because of some use of uninitialized memory in the escape analysis. If that's the reason, it will go away when we convert the compiler to Go. (And if not, we'll debug it the next time.) LGTM=khr R=r, khr CC=austin, golang-codereviews, iant, rlh https://golang.org/cl/174950043
2014-11-12 12:54:31 -07:00
// at the top of the system stack because the one at the top of
// the system stack terminates the stack walk (see topofstack()).
TEXT runtime·systemstack_switch(SB), NOSPLIT, $0-0
RET
[dev.cc] runtime: delete scalararg, ptrarg; rename onM to systemstack Scalararg and ptrarg are not "signal safe". Go code filling them out can be interrupted by a signal, and then the signal handler runs, and if it also ends up in Go code that uses scalararg or ptrarg, now the old values have been smashed. For the pieces of code that do need to run in a signal handler, we introduced onM_signalok, which is really just onM except that the _signalok is meant to convey that the caller asserts that scalarg and ptrarg will be restored to their old values after the call (instead of the usual behavior, zeroing them). Scalararg and ptrarg are also untyped and therefore error-prone. Go code can always pass a closure instead of using scalararg and ptrarg; they were only really necessary for C code. And there's no more C code. For all these reasons, delete scalararg and ptrarg, converting the few remaining references to use closures. Once those are gone, there is no need for a distinction between onM and onM_signalok, so replace both with a single function equivalent to the current onM_signalok (that is, it can be called on any of the curg, g0, and gsignal stacks). The name onM and the phrase 'm stack' are misnomers, because on most system an M has two system stacks: the main thread stack and the signal handling stack. Correct the misnomer by naming the replacement function systemstack. Fix a few references to "M stack" in code. The main motivation for this change is to eliminate scalararg/ptrarg. Rick and I have already seen them cause problems because the calling sequence m.ptrarg[0] = p is a heap pointer assignment, so it gets a write barrier. The write barrier also uses onM, so it has all the same problems as if it were being invoked by a signal handler. We worked around this by saving and restoring the old values and by calling onM_signalok, but there's no point in keeping this nice home for bugs around any longer. This CL also changes funcline to return the file name as a result instead of filling in a passed-in *string. (The *string signature is left over from when the code was written in and called from C.) That's arguably an unrelated change, except that once I had done the ptrarg/scalararg/onM cleanup I started getting false positives about the *string argument escaping (not allowed in package runtime). The compiler is wrong, but the easiest fix is to write the code like Go code instead of like C code. I am a bit worried that the compiler is wrong because of some use of uninitialized memory in the escape analysis. If that's the reason, it will go away when we convert the compiler to Go. (And if not, we'll debug it the next time.) LGTM=khr R=r, khr CC=austin, golang-codereviews, iant, rlh https://golang.org/cl/174950043
2014-11-12 12:54:31 -07:00
// func systemstack(fn func())
TEXT runtime·systemstack(SB), NOSPLIT, $0-8
MOVQ fn+0(FP), DI // DI = fn
get_tls(CX)
MOVQ g(CX), AX // AX = g
MOVQ g_m(AX), BX // BX = m
[dev.cc] runtime: delete scalararg, ptrarg; rename onM to systemstack Scalararg and ptrarg are not "signal safe". Go code filling them out can be interrupted by a signal, and then the signal handler runs, and if it also ends up in Go code that uses scalararg or ptrarg, now the old values have been smashed. For the pieces of code that do need to run in a signal handler, we introduced onM_signalok, which is really just onM except that the _signalok is meant to convey that the caller asserts that scalarg and ptrarg will be restored to their old values after the call (instead of the usual behavior, zeroing them). Scalararg and ptrarg are also untyped and therefore error-prone. Go code can always pass a closure instead of using scalararg and ptrarg; they were only really necessary for C code. And there's no more C code. For all these reasons, delete scalararg and ptrarg, converting the few remaining references to use closures. Once those are gone, there is no need for a distinction between onM and onM_signalok, so replace both with a single function equivalent to the current onM_signalok (that is, it can be called on any of the curg, g0, and gsignal stacks). The name onM and the phrase 'm stack' are misnomers, because on most system an M has two system stacks: the main thread stack and the signal handling stack. Correct the misnomer by naming the replacement function systemstack. Fix a few references to "M stack" in code. The main motivation for this change is to eliminate scalararg/ptrarg. Rick and I have already seen them cause problems because the calling sequence m.ptrarg[0] = p is a heap pointer assignment, so it gets a write barrier. The write barrier also uses onM, so it has all the same problems as if it were being invoked by a signal handler. We worked around this by saving and restoring the old values and by calling onM_signalok, but there's no point in keeping this nice home for bugs around any longer. This CL also changes funcline to return the file name as a result instead of filling in a passed-in *string. (The *string signature is left over from when the code was written in and called from C.) That's arguably an unrelated change, except that once I had done the ptrarg/scalararg/onM cleanup I started getting false positives about the *string argument escaping (not allowed in package runtime). The compiler is wrong, but the easiest fix is to write the code like Go code instead of like C code. I am a bit worried that the compiler is wrong because of some use of uninitialized memory in the escape analysis. If that's the reason, it will go away when we convert the compiler to Go. (And if not, we'll debug it the next time.) LGTM=khr R=r, khr CC=austin, golang-codereviews, iant, rlh https://golang.org/cl/174950043
2014-11-12 12:54:31 -07:00
MOVQ m_gsignal(BX), DX // DX = gsignal
CMPQ AX, DX
[dev.cc] runtime: delete scalararg, ptrarg; rename onM to systemstack Scalararg and ptrarg are not "signal safe". Go code filling them out can be interrupted by a signal, and then the signal handler runs, and if it also ends up in Go code that uses scalararg or ptrarg, now the old values have been smashed. For the pieces of code that do need to run in a signal handler, we introduced onM_signalok, which is really just onM except that the _signalok is meant to convey that the caller asserts that scalarg and ptrarg will be restored to their old values after the call (instead of the usual behavior, zeroing them). Scalararg and ptrarg are also untyped and therefore error-prone. Go code can always pass a closure instead of using scalararg and ptrarg; they were only really necessary for C code. And there's no more C code. For all these reasons, delete scalararg and ptrarg, converting the few remaining references to use closures. Once those are gone, there is no need for a distinction between onM and onM_signalok, so replace both with a single function equivalent to the current onM_signalok (that is, it can be called on any of the curg, g0, and gsignal stacks). The name onM and the phrase 'm stack' are misnomers, because on most system an M has two system stacks: the main thread stack and the signal handling stack. Correct the misnomer by naming the replacement function systemstack. Fix a few references to "M stack" in code. The main motivation for this change is to eliminate scalararg/ptrarg. Rick and I have already seen them cause problems because the calling sequence m.ptrarg[0] = p is a heap pointer assignment, so it gets a write barrier. The write barrier also uses onM, so it has all the same problems as if it were being invoked by a signal handler. We worked around this by saving and restoring the old values and by calling onM_signalok, but there's no point in keeping this nice home for bugs around any longer. This CL also changes funcline to return the file name as a result instead of filling in a passed-in *string. (The *string signature is left over from when the code was written in and called from C.) That's arguably an unrelated change, except that once I had done the ptrarg/scalararg/onM cleanup I started getting false positives about the *string argument escaping (not allowed in package runtime). The compiler is wrong, but the easiest fix is to write the code like Go code instead of like C code. I am a bit worried that the compiler is wrong because of some use of uninitialized memory in the escape analysis. If that's the reason, it will go away when we convert the compiler to Go. (And if not, we'll debug it the next time.) LGTM=khr R=r, khr CC=austin, golang-codereviews, iant, rlh https://golang.org/cl/174950043
2014-11-12 12:54:31 -07:00
JEQ noswitch
runtime: reject onM calls from gsignal stack The implementation and use patterns of onM assume that they run on either the m->curg or m->g0 stack. Calling onM from m->gsignal has two problems: (1) When not on g0, onM switches to g0 and then "back" to curg. If we didn't start at curg, bad things happen. (2) The use of scalararg/ptrarg to pass C arguments and results assumes that there is only one onM call at a time. If a gsignal starts running, it may have interrupted the setup/teardown of the args for an onM on the curg or g0 stack. Using scalararg/ptrarg itself would smash those. We can fix (1) by remembering what g was running before the switch. We can fix (2) by requiring that uses of onM that might happen on a signal handling stack must save the old scalararg/ptrarg and restore them after the call, instead of zeroing them. The only sane way to do this is to introduce a separate onM_signalsafe that omits the signal check, and then if you see a call to onM_signalsafe you know the surrounding code must preserve the old scalararg/ptrarg values. (The implementation would be that onM_signalsafe just calls fn if on the signal stack or else jumps to onM. It's not necessary to have two whole copies of the function.) (2) is not a problem if the caller and callee are both Go and a closure is used instead of the scalararg/ptrarg slots. For now, I think we can avoid calling onM from code executing on gsignal stacks, so just reject it. In the long term, (2) goes away (as do the scalararg/ptrarg slots) once everything is in Go, and at that point fixing (1) would be trivial and maybe worth doing just for regularity. LGTM=iant R=golang-codereviews, iant CC=dvyukov, golang-codereviews, khr, r https://golang.org/cl/135400043
2014-09-03 22:10:10 -06:00
MOVQ m_g0(BX), DX // DX = g0
CMPQ AX, DX
[dev.cc] runtime: delete scalararg, ptrarg; rename onM to systemstack Scalararg and ptrarg are not "signal safe". Go code filling them out can be interrupted by a signal, and then the signal handler runs, and if it also ends up in Go code that uses scalararg or ptrarg, now the old values have been smashed. For the pieces of code that do need to run in a signal handler, we introduced onM_signalok, which is really just onM except that the _signalok is meant to convey that the caller asserts that scalarg and ptrarg will be restored to their old values after the call (instead of the usual behavior, zeroing them). Scalararg and ptrarg are also untyped and therefore error-prone. Go code can always pass a closure instead of using scalararg and ptrarg; they were only really necessary for C code. And there's no more C code. For all these reasons, delete scalararg and ptrarg, converting the few remaining references to use closures. Once those are gone, there is no need for a distinction between onM and onM_signalok, so replace both with a single function equivalent to the current onM_signalok (that is, it can be called on any of the curg, g0, and gsignal stacks). The name onM and the phrase 'm stack' are misnomers, because on most system an M has two system stacks: the main thread stack and the signal handling stack. Correct the misnomer by naming the replacement function systemstack. Fix a few references to "M stack" in code. The main motivation for this change is to eliminate scalararg/ptrarg. Rick and I have already seen them cause problems because the calling sequence m.ptrarg[0] = p is a heap pointer assignment, so it gets a write barrier. The write barrier also uses onM, so it has all the same problems as if it were being invoked by a signal handler. We worked around this by saving and restoring the old values and by calling onM_signalok, but there's no point in keeping this nice home for bugs around any longer. This CL also changes funcline to return the file name as a result instead of filling in a passed-in *string. (The *string signature is left over from when the code was written in and called from C.) That's arguably an unrelated change, except that once I had done the ptrarg/scalararg/onM cleanup I started getting false positives about the *string argument escaping (not allowed in package runtime). The compiler is wrong, but the easiest fix is to write the code like Go code instead of like C code. I am a bit worried that the compiler is wrong because of some use of uninitialized memory in the escape analysis. If that's the reason, it will go away when we convert the compiler to Go. (And if not, we'll debug it the next time.) LGTM=khr R=r, khr CC=austin, golang-codereviews, iant, rlh https://golang.org/cl/174950043
2014-11-12 12:54:31 -07:00
JEQ noswitch
MOVQ m_curg(BX), R8
CMPQ AX, R8
[dev.cc] runtime: delete scalararg, ptrarg; rename onM to systemstack Scalararg and ptrarg are not "signal safe". Go code filling them out can be interrupted by a signal, and then the signal handler runs, and if it also ends up in Go code that uses scalararg or ptrarg, now the old values have been smashed. For the pieces of code that do need to run in a signal handler, we introduced onM_signalok, which is really just onM except that the _signalok is meant to convey that the caller asserts that scalarg and ptrarg will be restored to their old values after the call (instead of the usual behavior, zeroing them). Scalararg and ptrarg are also untyped and therefore error-prone. Go code can always pass a closure instead of using scalararg and ptrarg; they were only really necessary for C code. And there's no more C code. For all these reasons, delete scalararg and ptrarg, converting the few remaining references to use closures. Once those are gone, there is no need for a distinction between onM and onM_signalok, so replace both with a single function equivalent to the current onM_signalok (that is, it can be called on any of the curg, g0, and gsignal stacks). The name onM and the phrase 'm stack' are misnomers, because on most system an M has two system stacks: the main thread stack and the signal handling stack. Correct the misnomer by naming the replacement function systemstack. Fix a few references to "M stack" in code. The main motivation for this change is to eliminate scalararg/ptrarg. Rick and I have already seen them cause problems because the calling sequence m.ptrarg[0] = p is a heap pointer assignment, so it gets a write barrier. The write barrier also uses onM, so it has all the same problems as if it were being invoked by a signal handler. We worked around this by saving and restoring the old values and by calling onM_signalok, but there's no point in keeping this nice home for bugs around any longer. This CL also changes funcline to return the file name as a result instead of filling in a passed-in *string. (The *string signature is left over from when the code was written in and called from C.) That's arguably an unrelated change, except that once I had done the ptrarg/scalararg/onM cleanup I started getting false positives about the *string argument escaping (not allowed in package runtime). The compiler is wrong, but the easiest fix is to write the code like Go code instead of like C code. I am a bit worried that the compiler is wrong because of some use of uninitialized memory in the escape analysis. If that's the reason, it will go away when we convert the compiler to Go. (And if not, we'll debug it the next time.) LGTM=khr R=r, khr CC=austin, golang-codereviews, iant, rlh https://golang.org/cl/174950043
2014-11-12 12:54:31 -07:00
JEQ switch
runtime: reject onM calls from gsignal stack The implementation and use patterns of onM assume that they run on either the m->curg or m->g0 stack. Calling onM from m->gsignal has two problems: (1) When not on g0, onM switches to g0 and then "back" to curg. If we didn't start at curg, bad things happen. (2) The use of scalararg/ptrarg to pass C arguments and results assumes that there is only one onM call at a time. If a gsignal starts running, it may have interrupted the setup/teardown of the args for an onM on the curg or g0 stack. Using scalararg/ptrarg itself would smash those. We can fix (1) by remembering what g was running before the switch. We can fix (2) by requiring that uses of onM that might happen on a signal handling stack must save the old scalararg/ptrarg and restore them after the call, instead of zeroing them. The only sane way to do this is to introduce a separate onM_signalsafe that omits the signal check, and then if you see a call to onM_signalsafe you know the surrounding code must preserve the old scalararg/ptrarg values. (The implementation would be that onM_signalsafe just calls fn if on the signal stack or else jumps to onM. It's not necessary to have two whole copies of the function.) (2) is not a problem if the caller and callee are both Go and a closure is used instead of the scalararg/ptrarg slots. For now, I think we can avoid calling onM from code executing on gsignal stacks, so just reject it. In the long term, (2) goes away (as do the scalararg/ptrarg slots) once everything is in Go, and at that point fixing (1) would be trivial and maybe worth doing just for regularity. LGTM=iant R=golang-codereviews, iant CC=dvyukov, golang-codereviews, khr, r https://golang.org/cl/135400043
2014-09-03 22:10:10 -06:00
[dev.cc] runtime: delete scalararg, ptrarg; rename onM to systemstack Scalararg and ptrarg are not "signal safe". Go code filling them out can be interrupted by a signal, and then the signal handler runs, and if it also ends up in Go code that uses scalararg or ptrarg, now the old values have been smashed. For the pieces of code that do need to run in a signal handler, we introduced onM_signalok, which is really just onM except that the _signalok is meant to convey that the caller asserts that scalarg and ptrarg will be restored to their old values after the call (instead of the usual behavior, zeroing them). Scalararg and ptrarg are also untyped and therefore error-prone. Go code can always pass a closure instead of using scalararg and ptrarg; they were only really necessary for C code. And there's no more C code. For all these reasons, delete scalararg and ptrarg, converting the few remaining references to use closures. Once those are gone, there is no need for a distinction between onM and onM_signalok, so replace both with a single function equivalent to the current onM_signalok (that is, it can be called on any of the curg, g0, and gsignal stacks). The name onM and the phrase 'm stack' are misnomers, because on most system an M has two system stacks: the main thread stack and the signal handling stack. Correct the misnomer by naming the replacement function systemstack. Fix a few references to "M stack" in code. The main motivation for this change is to eliminate scalararg/ptrarg. Rick and I have already seen them cause problems because the calling sequence m.ptrarg[0] = p is a heap pointer assignment, so it gets a write barrier. The write barrier also uses onM, so it has all the same problems as if it were being invoked by a signal handler. We worked around this by saving and restoring the old values and by calling onM_signalok, but there's no point in keeping this nice home for bugs around any longer. This CL also changes funcline to return the file name as a result instead of filling in a passed-in *string. (The *string signature is left over from when the code was written in and called from C.) That's arguably an unrelated change, except that once I had done the ptrarg/scalararg/onM cleanup I started getting false positives about the *string argument escaping (not allowed in package runtime). The compiler is wrong, but the easiest fix is to write the code like Go code instead of like C code. I am a bit worried that the compiler is wrong because of some use of uninitialized memory in the escape analysis. If that's the reason, it will go away when we convert the compiler to Go. (And if not, we'll debug it the next time.) LGTM=khr R=r, khr CC=austin, golang-codereviews, iant, rlh https://golang.org/cl/174950043
2014-11-12 12:54:31 -07:00
// Bad: g is not gsignal, not g0, not curg. What is it?
MOVQ $runtime·badsystemstack(SB), AX
runtime: reject onM calls from gsignal stack The implementation and use patterns of onM assume that they run on either the m->curg or m->g0 stack. Calling onM from m->gsignal has two problems: (1) When not on g0, onM switches to g0 and then "back" to curg. If we didn't start at curg, bad things happen. (2) The use of scalararg/ptrarg to pass C arguments and results assumes that there is only one onM call at a time. If a gsignal starts running, it may have interrupted the setup/teardown of the args for an onM on the curg or g0 stack. Using scalararg/ptrarg itself would smash those. We can fix (1) by remembering what g was running before the switch. We can fix (2) by requiring that uses of onM that might happen on a signal handling stack must save the old scalararg/ptrarg and restore them after the call, instead of zeroing them. The only sane way to do this is to introduce a separate onM_signalsafe that omits the signal check, and then if you see a call to onM_signalsafe you know the surrounding code must preserve the old scalararg/ptrarg values. (The implementation would be that onM_signalsafe just calls fn if on the signal stack or else jumps to onM. It's not necessary to have two whole copies of the function.) (2) is not a problem if the caller and callee are both Go and a closure is used instead of the scalararg/ptrarg slots. For now, I think we can avoid calling onM from code executing on gsignal stacks, so just reject it. In the long term, (2) goes away (as do the scalararg/ptrarg slots) once everything is in Go, and at that point fixing (1) would be trivial and maybe worth doing just for regularity. LGTM=iant R=golang-codereviews, iant CC=dvyukov, golang-codereviews, khr, r https://golang.org/cl/135400043
2014-09-03 22:10:10 -06:00
CALL AX
[dev.cc] runtime: delete scalararg, ptrarg; rename onM to systemstack Scalararg and ptrarg are not "signal safe". Go code filling them out can be interrupted by a signal, and then the signal handler runs, and if it also ends up in Go code that uses scalararg or ptrarg, now the old values have been smashed. For the pieces of code that do need to run in a signal handler, we introduced onM_signalok, which is really just onM except that the _signalok is meant to convey that the caller asserts that scalarg and ptrarg will be restored to their old values after the call (instead of the usual behavior, zeroing them). Scalararg and ptrarg are also untyped and therefore error-prone. Go code can always pass a closure instead of using scalararg and ptrarg; they were only really necessary for C code. And there's no more C code. For all these reasons, delete scalararg and ptrarg, converting the few remaining references to use closures. Once those are gone, there is no need for a distinction between onM and onM_signalok, so replace both with a single function equivalent to the current onM_signalok (that is, it can be called on any of the curg, g0, and gsignal stacks). The name onM and the phrase 'm stack' are misnomers, because on most system an M has two system stacks: the main thread stack and the signal handling stack. Correct the misnomer by naming the replacement function systemstack. Fix a few references to "M stack" in code. The main motivation for this change is to eliminate scalararg/ptrarg. Rick and I have already seen them cause problems because the calling sequence m.ptrarg[0] = p is a heap pointer assignment, so it gets a write barrier. The write barrier also uses onM, so it has all the same problems as if it were being invoked by a signal handler. We worked around this by saving and restoring the old values and by calling onM_signalok, but there's no point in keeping this nice home for bugs around any longer. This CL also changes funcline to return the file name as a result instead of filling in a passed-in *string. (The *string signature is left over from when the code was written in and called from C.) That's arguably an unrelated change, except that once I had done the ptrarg/scalararg/onM cleanup I started getting false positives about the *string argument escaping (not allowed in package runtime). The compiler is wrong, but the easiest fix is to write the code like Go code instead of like C code. I am a bit worried that the compiler is wrong because of some use of uninitialized memory in the escape analysis. If that's the reason, it will go away when we convert the compiler to Go. (And if not, we'll debug it the next time.) LGTM=khr R=r, khr CC=austin, golang-codereviews, iant, rlh https://golang.org/cl/174950043
2014-11-12 12:54:31 -07:00
switch:
// save our state in g->sched. Pretend to
[dev.cc] runtime: delete scalararg, ptrarg; rename onM to systemstack Scalararg and ptrarg are not "signal safe". Go code filling them out can be interrupted by a signal, and then the signal handler runs, and if it also ends up in Go code that uses scalararg or ptrarg, now the old values have been smashed. For the pieces of code that do need to run in a signal handler, we introduced onM_signalok, which is really just onM except that the _signalok is meant to convey that the caller asserts that scalarg and ptrarg will be restored to their old values after the call (instead of the usual behavior, zeroing them). Scalararg and ptrarg are also untyped and therefore error-prone. Go code can always pass a closure instead of using scalararg and ptrarg; they were only really necessary for C code. And there's no more C code. For all these reasons, delete scalararg and ptrarg, converting the few remaining references to use closures. Once those are gone, there is no need for a distinction between onM and onM_signalok, so replace both with a single function equivalent to the current onM_signalok (that is, it can be called on any of the curg, g0, and gsignal stacks). The name onM and the phrase 'm stack' are misnomers, because on most system an M has two system stacks: the main thread stack and the signal handling stack. Correct the misnomer by naming the replacement function systemstack. Fix a few references to "M stack" in code. The main motivation for this change is to eliminate scalararg/ptrarg. Rick and I have already seen them cause problems because the calling sequence m.ptrarg[0] = p is a heap pointer assignment, so it gets a write barrier. The write barrier also uses onM, so it has all the same problems as if it were being invoked by a signal handler. We worked around this by saving and restoring the old values and by calling onM_signalok, but there's no point in keeping this nice home for bugs around any longer. This CL also changes funcline to return the file name as a result instead of filling in a passed-in *string. (The *string signature is left over from when the code was written in and called from C.) That's arguably an unrelated change, except that once I had done the ptrarg/scalararg/onM cleanup I started getting false positives about the *string argument escaping (not allowed in package runtime). The compiler is wrong, but the easiest fix is to write the code like Go code instead of like C code. I am a bit worried that the compiler is wrong because of some use of uninitialized memory in the escape analysis. If that's the reason, it will go away when we convert the compiler to Go. (And if not, we'll debug it the next time.) LGTM=khr R=r, khr CC=austin, golang-codereviews, iant, rlh https://golang.org/cl/174950043
2014-11-12 12:54:31 -07:00
// be systemstack_switch if the G stack is scanned.
MOVQ $runtime·systemstack_switch(SB), SI
MOVQ SI, (g_sched+gobuf_pc)(AX)
MOVQ SP, (g_sched+gobuf_sp)(AX)
MOVQ AX, (g_sched+gobuf_g)(AX)
MOVQ BP, (g_sched+gobuf_bp)(AX)
// switch to g0
MOVQ DX, g(CX)
MOVQ (g_sched+gobuf_sp)(DX), BX
[dev.cc] runtime: delete scalararg, ptrarg; rename onM to systemstack Scalararg and ptrarg are not "signal safe". Go code filling them out can be interrupted by a signal, and then the signal handler runs, and if it also ends up in Go code that uses scalararg or ptrarg, now the old values have been smashed. For the pieces of code that do need to run in a signal handler, we introduced onM_signalok, which is really just onM except that the _signalok is meant to convey that the caller asserts that scalarg and ptrarg will be restored to their old values after the call (instead of the usual behavior, zeroing them). Scalararg and ptrarg are also untyped and therefore error-prone. Go code can always pass a closure instead of using scalararg and ptrarg; they were only really necessary for C code. And there's no more C code. For all these reasons, delete scalararg and ptrarg, converting the few remaining references to use closures. Once those are gone, there is no need for a distinction between onM and onM_signalok, so replace both with a single function equivalent to the current onM_signalok (that is, it can be called on any of the curg, g0, and gsignal stacks). The name onM and the phrase 'm stack' are misnomers, because on most system an M has two system stacks: the main thread stack and the signal handling stack. Correct the misnomer by naming the replacement function systemstack. Fix a few references to "M stack" in code. The main motivation for this change is to eliminate scalararg/ptrarg. Rick and I have already seen them cause problems because the calling sequence m.ptrarg[0] = p is a heap pointer assignment, so it gets a write barrier. The write barrier also uses onM, so it has all the same problems as if it were being invoked by a signal handler. We worked around this by saving and restoring the old values and by calling onM_signalok, but there's no point in keeping this nice home for bugs around any longer. This CL also changes funcline to return the file name as a result instead of filling in a passed-in *string. (The *string signature is left over from when the code was written in and called from C.) That's arguably an unrelated change, except that once I had done the ptrarg/scalararg/onM cleanup I started getting false positives about the *string argument escaping (not allowed in package runtime). The compiler is wrong, but the easiest fix is to write the code like Go code instead of like C code. I am a bit worried that the compiler is wrong because of some use of uninitialized memory in the escape analysis. If that's the reason, it will go away when we convert the compiler to Go. (And if not, we'll debug it the next time.) LGTM=khr R=r, khr CC=austin, golang-codereviews, iant, rlh https://golang.org/cl/174950043
2014-11-12 12:54:31 -07:00
// make it look like mstart called systemstack on g0, to stop traceback
SUBQ $8, BX
MOVQ $runtime·mstart(SB), DX
MOVQ DX, 0(BX)
MOVQ BX, SP
// call target function
MOVQ DI, DX
MOVQ 0(DI), DI
CALL DI
// switch back to g
get_tls(CX)
MOVQ g(CX), AX
MOVQ g_m(AX), BX
MOVQ m_curg(BX), AX
MOVQ AX, g(CX)
MOVQ (g_sched+gobuf_sp)(AX), SP
MOVQ $0, (g_sched+gobuf_sp)(AX)
RET
[dev.cc] runtime: delete scalararg, ptrarg; rename onM to systemstack Scalararg and ptrarg are not "signal safe". Go code filling them out can be interrupted by a signal, and then the signal handler runs, and if it also ends up in Go code that uses scalararg or ptrarg, now the old values have been smashed. For the pieces of code that do need to run in a signal handler, we introduced onM_signalok, which is really just onM except that the _signalok is meant to convey that the caller asserts that scalarg and ptrarg will be restored to their old values after the call (instead of the usual behavior, zeroing them). Scalararg and ptrarg are also untyped and therefore error-prone. Go code can always pass a closure instead of using scalararg and ptrarg; they were only really necessary for C code. And there's no more C code. For all these reasons, delete scalararg and ptrarg, converting the few remaining references to use closures. Once those are gone, there is no need for a distinction between onM and onM_signalok, so replace both with a single function equivalent to the current onM_signalok (that is, it can be called on any of the curg, g0, and gsignal stacks). The name onM and the phrase 'm stack' are misnomers, because on most system an M has two system stacks: the main thread stack and the signal handling stack. Correct the misnomer by naming the replacement function systemstack. Fix a few references to "M stack" in code. The main motivation for this change is to eliminate scalararg/ptrarg. Rick and I have already seen them cause problems because the calling sequence m.ptrarg[0] = p is a heap pointer assignment, so it gets a write barrier. The write barrier also uses onM, so it has all the same problems as if it were being invoked by a signal handler. We worked around this by saving and restoring the old values and by calling onM_signalok, but there's no point in keeping this nice home for bugs around any longer. This CL also changes funcline to return the file name as a result instead of filling in a passed-in *string. (The *string signature is left over from when the code was written in and called from C.) That's arguably an unrelated change, except that once I had done the ptrarg/scalararg/onM cleanup I started getting false positives about the *string argument escaping (not allowed in package runtime). The compiler is wrong, but the easiest fix is to write the code like Go code instead of like C code. I am a bit worried that the compiler is wrong because of some use of uninitialized memory in the escape analysis. If that's the reason, it will go away when we convert the compiler to Go. (And if not, we'll debug it the next time.) LGTM=khr R=r, khr CC=austin, golang-codereviews, iant, rlh https://golang.org/cl/174950043
2014-11-12 12:54:31 -07:00
noswitch:
// already on m stack, just call directly
MOVQ DI, DX
MOVQ 0(DI), DI
CALL DI
RET
/*
* support for morestack
*/
// Called during function prolog when more stack is needed.
//
// The traceback routines see morestack on a g0 as being
// the top of a stack (for example, morestack calling newstack
// calling the scheduler calling newm calling gc), so we must
// record an argument size. For that purpose, it has no arguments.
TEXT runtime·morestack(SB),NOSPLIT,$0-0
// Cannot grow scheduler stack (m->g0).
get_tls(CX)
MOVQ g(CX), BX
MOVQ g_m(BX), BX
MOVQ m_g0(BX), SI
CMPQ g(CX), SI
JNE 2(PC)
INT $3
// Cannot grow signal stack (m->gsignal).
MOVQ m_gsignal(BX), SI
CMPQ g(CX), SI
JNE 2(PC)
INT $3
// Called from f.
// Set m->morebuf to f's caller.
MOVQ 8(SP), AX // f's caller's PC
MOVQ AX, (m_morebuf+gobuf_pc)(BX)
LEAQ 16(SP), AX // f's caller's SP
MOVQ AX, (m_morebuf+gobuf_sp)(BX)
get_tls(CX)
MOVQ g(CX), SI
MOVQ SI, (m_morebuf+gobuf_g)(BX)
runtime: record proper goroutine state during stack split Until now, the goroutine state has been scattered during the execution of newstack and oldstack. It's all there, and those routines know how to get back to a working goroutine, but other pieces of the system, like stack traces, do not. If something does interrupt the newstack or oldstack execution, the rest of the system can't understand the goroutine. For example, if newstack decides there is an overflow and calls throw, the stack tracer wouldn't dump the goroutine correctly. For newstack to save a useful state snapshot, it needs to be able to rewind the PC in the function that triggered the split back to the beginning of the function. (The PC is a few instructions in, just after the call to morestack.) To make that possible, we change the prologues to insert a jmp back to the beginning of the function after the call to morestack. That is, the prologue used to be roughly: TEXT myfunc check for split jmpcond nosplit call morestack nosplit: sub $xxx, sp Now an extra instruction is inserted after the call: TEXT myfunc start: check for split jmpcond nosplit call morestack jmp start nosplit: sub $xxx, sp The jmp is not executed directly. It is decoded and simulated by runtime.rewindmorestack to discover the beginning of the function, and then the call to morestack returns directly to the start label instead of to the jump instruction. So logically the jmp is still executed, just not by the cpu. The prologue thus repeats in the case of a function that needs a stack split, but against the cost of the split itself, the extra few instructions are noise. The repeated prologue has the nice effect of making a stack split double-check that the new stack is big enough: if morestack happens to return on a too-small stack, we'll now notice before corruption happens. The ability for newstack to rewind to the beginning of the function should help preemption too. If newstack decides that it was called for preemption instead of a stack split, it now has the goroutine state correctly paused if rescheduling is needed, and when the goroutine can run again, it can return to the start label on its original stack and re-execute the split check. Here is an example of a split stack overflow showing the full trace, without any special cases in the stack printer. (This one was triggered by making the split check incorrect.) runtime: newstack framesize=0x0 argsize=0x18 sp=0x6aebd0 stack=[0x6b0000, 0x6b0fa0] morebuf={pc:0x69f5b sp:0x6aebd8 lr:0x0} sched={pc:0x68880 sp:0x6aebd0 lr:0x0 ctxt:0x34e700} runtime: split stack overflow: 0x6aebd0 < 0x6b0000 fatal error: runtime: split stack overflow goroutine 1 [stack split]: runtime.mallocgc(0x290, 0x100000000, 0x1) /Users/rsc/g/go/src/pkg/runtime/zmalloc_darwin_amd64.c:21 fp=0x6aebd8 runtime.new() /Users/rsc/g/go/src/pkg/runtime/zmalloc_darwin_amd64.c:682 +0x5b fp=0x6aec08 go/build.(*Context).Import(0x5ae340, 0xc210030c71, 0xa, 0xc2100b4380, 0x1b, ...) /Users/rsc/g/go/src/pkg/go/build/build.go:424 +0x3a fp=0x6b00a0 main.loadImport(0xc210030c71, 0xa, 0xc2100b4380, 0x1b, 0xc2100b42c0, ...) /Users/rsc/g/go/src/cmd/go/pkg.go:249 +0x371 fp=0x6b01a8 main.(*Package).load(0xc21017c800, 0xc2100b42c0, 0xc2101828c0, 0x0, 0x0, ...) /Users/rsc/g/go/src/cmd/go/pkg.go:431 +0x2801 fp=0x6b0c98 main.loadPackage(0x369040, 0x7, 0xc2100b42c0, 0x0) /Users/rsc/g/go/src/cmd/go/pkg.go:709 +0x857 fp=0x6b0f80 ----- stack segment boundary ----- main.(*builder).action(0xc2100902a0, 0x0, 0x0, 0xc2100e6c00, 0xc2100e5750, ...) /Users/rsc/g/go/src/cmd/go/build.go:539 +0x437 fp=0x6b14a0 main.(*builder).action(0xc2100902a0, 0x0, 0x0, 0xc21015b400, 0x2, ...) /Users/rsc/g/go/src/cmd/go/build.go:528 +0x1d2 fp=0x6b1658 main.(*builder).test(0xc2100902a0, 0xc210092000, 0x0, 0x0, 0xc21008ff60, ...) /Users/rsc/g/go/src/cmd/go/test.go:622 +0x1b53 fp=0x6b1f68 ----- stack segment boundary ----- main.runTest(0x5a6b20, 0xc21000a020, 0x2, 0x2) /Users/rsc/g/go/src/cmd/go/test.go:366 +0xd09 fp=0x6a5cf0 main.main() /Users/rsc/g/go/src/cmd/go/main.go:161 +0x4f9 fp=0x6a5f78 runtime.main() /Users/rsc/g/go/src/pkg/runtime/proc.c:183 +0x92 fp=0x6a5fa0 runtime.goexit() /Users/rsc/g/go/src/pkg/runtime/proc.c:1266 fp=0x6a5fa8 And here is a seg fault during oldstack: SIGSEGV: segmentation violation PC=0x1b2a6 runtime.oldstack() /Users/rsc/g/go/src/pkg/runtime/stack.c:159 +0x76 runtime.lessstack() /Users/rsc/g/go/src/pkg/runtime/asm_amd64.s:270 +0x22 goroutine 1 [stack unsplit]: fmt.(*pp).printArg(0x2102e64e0, 0xe5c80, 0x2102c9220, 0x73, 0x0, ...) /Users/rsc/g/go/src/pkg/fmt/print.go:818 +0x3d3 fp=0x221031e6f8 fmt.(*pp).doPrintf(0x2102e64e0, 0x12fb20, 0x2, 0x221031eb98, 0x1, ...) /Users/rsc/g/go/src/pkg/fmt/print.go:1183 +0x15cb fp=0x221031eaf0 fmt.Sprintf(0x12fb20, 0x2, 0x221031eb98, 0x1, 0x1, ...) /Users/rsc/g/go/src/pkg/fmt/print.go:234 +0x67 fp=0x221031eb40 flag.(*stringValue).String(0x2102c9210, 0x1, 0x0) /Users/rsc/g/go/src/pkg/flag/flag.go:180 +0xb3 fp=0x221031ebb0 flag.(*FlagSet).Var(0x2102f6000, 0x293d38, 0x2102c9210, 0x143490, 0xa, ...) /Users/rsc/g/go/src/pkg/flag/flag.go:633 +0x40 fp=0x221031eca0 flag.(*FlagSet).StringVar(0x2102f6000, 0x2102c9210, 0x143490, 0xa, 0x12fa60, ...) /Users/rsc/g/go/src/pkg/flag/flag.go:550 +0x91 fp=0x221031ece8 flag.(*FlagSet).String(0x2102f6000, 0x143490, 0xa, 0x12fa60, 0x0, ...) /Users/rsc/g/go/src/pkg/flag/flag.go:563 +0x87 fp=0x221031ed38 flag.String(0x143490, 0xa, 0x12fa60, 0x0, 0x161950, ...) /Users/rsc/g/go/src/pkg/flag/flag.go:570 +0x6b fp=0x221031ed80 testing.init() /Users/rsc/g/go/src/pkg/testing/testing.go:-531 +0xbb fp=0x221031edc0 strings_test.init() /Users/rsc/g/go/src/pkg/strings/strings_test.go:1115 +0x62 fp=0x221031ef70 main.init() strings/_test/_testmain.go:90 +0x3d fp=0x221031ef78 runtime.main() /Users/rsc/g/go/src/pkg/runtime/proc.c:180 +0x8a fp=0x221031efa0 runtime.goexit() /Users/rsc/g/go/src/pkg/runtime/proc.c:1269 fp=0x221031efa8 goroutine 2 [runnable]: runtime.MHeap_Scavenger() /Users/rsc/g/go/src/pkg/runtime/mheap.c:438 runtime.goexit() /Users/rsc/g/go/src/pkg/runtime/proc.c:1269 created by runtime.main /Users/rsc/g/go/src/pkg/runtime/proc.c:166 rax 0x23ccc0 rbx 0x23ccc0 rcx 0x0 rdx 0x38 rdi 0x2102c0170 rsi 0x221032cfe0 rbp 0x221032cfa0 rsp 0x7fff5fbff5b0 r8 0x2102c0120 r9 0x221032cfa0 r10 0x221032c000 r11 0x104ce8 r12 0xe5c80 r13 0x1be82baac718 r14 0x13091135f7d69200 r15 0x0 rip 0x1b2a6 rflags 0x10246 cs 0x2b fs 0x0 gs 0x0 Fixes #5723. R=r, dvyukov, go.peter.90, dave, iant CC=golang-dev https://golang.org/cl/10360048
2013-06-27 09:32:01 -06:00
// Set g->sched to context in f.
MOVQ 0(SP), AX // f's PC
MOVQ AX, (g_sched+gobuf_pc)(SI)
MOVQ SI, (g_sched+gobuf_g)(SI)
LEAQ 8(SP), AX // f's SP
MOVQ AX, (g_sched+gobuf_sp)(SI)
MOVQ DX, (g_sched+gobuf_ctxt)(SI)
MOVQ BP, (g_sched+gobuf_bp)(SI)
runtime: scheduler, cgo reorganization * Change use of m->g0 stack (aka scheduler stack). * Provide runtime.mcall(f) to invoke f() on m->g0 stack. * Replace scheduler loop entry with runtime.mcall(schedule). Runtime.mcall eliminates the need for fake scheduler states that exist just to run a bit of code on the m->g0 stack (Grecovery, Gstackalloc). The elimination of the scheduler as a loop that stops and starts using gosave and gogo fixes a bad interaction with the way cgo uses the m->g0 stack. Cgo runs external (gcc-compiled) C functions on that stack, and then when calling back into Go, it sets m->g0->sched.sp below the added call frames, so that other uses of m->g0's stack will not interfere with those frames. Unfortunately, gogo (longjmp) back to the scheduler loop at this point would end up running scheduler with the lower sp, which no longer points at a valid stack frame for a call to scheduler. If scheduler then wrote any function call arguments or local variables to where it expected the stack frame to be, it would overwrite other data on the stack. I realized this possibility while debugging a problem with calling complex Go code in a Go -> C -> Go cgo callback. This wasn't the bug I was looking for, it turns out, but I believe it is a real bug nonetheless. Switching to runtime.mcall, which only adds new frames to the stack and never jumps into functions running in existing ones, fixes this bug. * Move cgo-related code out of proc.c into cgocall.c. * Add very large comment describing cgo call sequences. * Simpilify, regularize cgo function implementations and names. * Add test suite as misc/cgo/test. Now the Go -> C path calls cgocall, which calls asmcgocall, and the C -> Go path calls cgocallback, which calls cgocallbackg. The shuffling, which affects mainly the callback case, moves most of the callback implementation to cgocallback running on the m->curg stack (not the m->g0 scheduler stack) and only while accounted for with $GOMAXPROCS (between calls to exitsyscall and entersyscall). The previous callback code did not block in startcgocallback's approximation to exitsyscall, so if, say, the garbage collector were running, it would still barge in and start doing things like call malloc. Similarly endcgocallback's approximation of entersyscall did not call matchmg to kick off new OS threads when necessary, which caused the bug in issue 1560. Fixes #1560. R=iant CC=golang-dev https://golang.org/cl/4253054
2011-03-07 08:37:42 -07:00
// Call newstack on m->g0's stack.
MOVQ m_g0(BX), BX
MOVQ BX, g(CX)
MOVQ (g_sched+gobuf_sp)(BX), SP
CALL runtime·newstack(SB)
MOVQ $0, 0x1003 // crash if newstack returns
RET
// morestack but not preserving ctxt.
TEXT runtime·morestack_noctxt(SB),NOSPLIT,$0
MOVL $0, DX
JMP runtime·morestack(SB)
runtime: implement GC stack barriers This commit implements stack barriers to minimize the amount of stack re-scanning that must be done during mark termination. Currently the GC scans stacks of active goroutines twice during every GC cycle: once at the beginning during root discovery and once at the end during mark termination. The second scan happens while the world is stopped and guarantees that we've seen all of the roots (since there are no write barriers on writes to local stack variables). However, this means pause time is proportional to stack size. In particularly recursive programs, this can drive pause time up past our 10ms goal (e.g., it takes about 150ms to scan a 50MB heap). Re-scanning the entire stack is rarely necessary, especially for large stacks, because usually most of the frames on the stack were not active between the first and second scans and hence any changes to these frames (via non-escaping pointers passed down the stack) were tracked by write barriers. To efficiently track how far a stack has been unwound since the first scan (and, hence, how much needs to be re-scanned), this commit introduces stack barriers. During the first scan, at exponentially spaced points in each stack, the scan overwrites return PCs with the PC of the stack barrier function. When "returned" to, the stack barrier function records how far the stack has unwound and jumps to the original return PC for that point in the stack. Then the second scan only needs to proceed as far as the lowest barrier that hasn't been hit. For deeply recursive programs, this substantially reduces mark termination time (and hence pause time). For the goscheme example linked in issue #10898, prior to this change, mark termination times were typically between 100 and 500ms; with this change, mark termination times are typically between 10 and 20ms. As a result of the reduced stack scanning work, this reduces overall execution time of the goscheme example by 20%. Fixes #10898. The effect of this on programs that are not deeply recursive is minimal: name old time/op new time/op delta BinaryTree17 3.16s ± 2% 3.26s ± 1% +3.31% (p=0.000 n=19+19) Fannkuch11 2.42s ± 1% 2.48s ± 1% +2.24% (p=0.000 n=17+19) FmtFprintfEmpty 50.0ns ± 3% 49.8ns ± 1% ~ (p=0.534 n=20+19) FmtFprintfString 173ns ± 0% 175ns ± 0% +1.49% (p=0.000 n=16+19) FmtFprintfInt 170ns ± 1% 175ns ± 1% +2.97% (p=0.000 n=20+19) FmtFprintfIntInt 288ns ± 0% 295ns ± 0% +2.73% (p=0.000 n=16+19) FmtFprintfPrefixedInt 242ns ± 1% 252ns ± 1% +4.13% (p=0.000 n=18+18) FmtFprintfFloat 324ns ± 0% 323ns ± 0% -0.36% (p=0.000 n=20+19) FmtManyArgs 1.14µs ± 0% 1.12µs ± 1% -1.01% (p=0.000 n=18+19) GobDecode 8.88ms ± 1% 8.87ms ± 0% ~ (p=0.480 n=19+18) GobEncode 6.80ms ± 1% 6.85ms ± 0% +0.82% (p=0.000 n=20+18) Gzip 363ms ± 1% 363ms ± 1% ~ (p=0.077 n=18+20) Gunzip 90.6ms ± 0% 90.0ms ± 1% -0.71% (p=0.000 n=17+18) HTTPClientServer 51.5µs ± 1% 50.8µs ± 1% -1.32% (p=0.000 n=18+18) JSONEncode 17.0ms ± 0% 17.1ms ± 0% +0.40% (p=0.000 n=18+17) JSONDecode 61.8ms ± 0% 63.8ms ± 1% +3.11% (p=0.000 n=18+17) Mandelbrot200 3.84ms ± 0% 3.84ms ± 1% ~ (p=0.583 n=19+19) GoParse 3.71ms ± 1% 3.72ms ± 1% ~ (p=0.159 n=18+19) RegexpMatchEasy0_32 100ns ± 0% 100ns ± 1% -0.19% (p=0.033 n=17+19) RegexpMatchEasy0_1K 342ns ± 1% 331ns ± 0% -3.41% (p=0.000 n=19+19) RegexpMatchEasy1_32 82.5ns ± 0% 81.7ns ± 0% -0.98% (p=0.000 n=18+18) RegexpMatchEasy1_1K 505ns ± 0% 494ns ± 1% -2.16% (p=0.000 n=18+18) RegexpMatchMedium_32 137ns ± 1% 137ns ± 1% -0.24% (p=0.048 n=20+18) RegexpMatchMedium_1K 41.6µs ± 0% 41.3µs ± 1% -0.57% (p=0.004 n=18+20) RegexpMatchHard_32 2.11µs ± 0% 2.11µs ± 1% +0.20% (p=0.037 n=17+19) RegexpMatchHard_1K 63.9µs ± 2% 63.3µs ± 0% -0.99% (p=0.000 n=20+17) Revcomp 560ms ± 1% 522ms ± 0% -6.87% (p=0.000 n=18+16) Template 75.0ms ± 0% 75.1ms ± 1% +0.18% (p=0.013 n=18+19) TimeParse 358ns ± 1% 364ns ± 0% +1.74% (p=0.000 n=20+15) TimeFormat 360ns ± 0% 372ns ± 0% +3.55% (p=0.000 n=20+18) Change-Id: If8a9bfae6c128d15a4f405e02bcfa50129df82a2 Reviewed-on: https://go-review.googlesource.com/10314 Reviewed-by: Russ Cox <rsc@golang.org> Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-05-20 14:30:49 -06:00
TEXT runtime·stackBarrier(SB),NOSPLIT,$0
// We came here via a RET to an overwritten return PC.
// AX may be live. Other registers are available.
// Get the original return PC, g.stkbar[g.stkbarPos].savedLRVal.
get_tls(CX)
MOVQ g(CX), CX
MOVQ (g_stkbar+slice_array)(CX), DX
MOVQ g_stkbarPos(CX), BX
IMULQ $stkbar__size, BX // Too big for SIB.
MOVQ stkbar_savedLRVal(DX)(BX*1), BX
// Record that this stack barrier was hit.
ADDQ $1, g_stkbarPos(CX)
// Jump to the original return PC.
JMP BX
// reflectcall: call a function with the given argument list
// func call(argtype *_type, f *FuncVal, arg *byte, argsize, retoffset uint32).
// we don't have variable-sized frames, so we use a small number
// of constant-sized-frame functions to encode a few bits of size in the pc.
// Caution: ugly multiline assembly macros in your future!
#define DISPATCH(NAME,MAXSIZE) \
CMPQ CX, $MAXSIZE; \
JA 3(PC); \
MOVQ $NAME(SB), AX; \
JMP AX
// Note: can't just "JMP NAME(SB)" - bad inlining results.
TEXT reflect·call(SB), NOSPLIT, $0-0
JMP ·reflectcall(SB)
TEXT ·reflectcall(SB), NOSPLIT, $0-32
MOVLQZX argsize+24(FP), CX
// NOTE(rsc): No call16, because CALLFN needs four words
// of argument space to invoke callwritebarrier.
DISPATCH(runtime·call32, 32)
DISPATCH(runtime·call64, 64)
DISPATCH(runtime·call128, 128)
DISPATCH(runtime·call256, 256)
DISPATCH(runtime·call512, 512)
DISPATCH(runtime·call1024, 1024)
DISPATCH(runtime·call2048, 2048)
DISPATCH(runtime·call4096, 4096)
DISPATCH(runtime·call8192, 8192)
DISPATCH(runtime·call16384, 16384)
DISPATCH(runtime·call32768, 32768)
DISPATCH(runtime·call65536, 65536)
DISPATCH(runtime·call131072, 131072)
DISPATCH(runtime·call262144, 262144)
DISPATCH(runtime·call524288, 524288)
DISPATCH(runtime·call1048576, 1048576)
DISPATCH(runtime·call2097152, 2097152)
DISPATCH(runtime·call4194304, 4194304)
DISPATCH(runtime·call8388608, 8388608)
DISPATCH(runtime·call16777216, 16777216)
DISPATCH(runtime·call33554432, 33554432)
DISPATCH(runtime·call67108864, 67108864)
DISPATCH(runtime·call134217728, 134217728)
DISPATCH(runtime·call268435456, 268435456)
DISPATCH(runtime·call536870912, 536870912)
DISPATCH(runtime·call1073741824, 1073741824)
MOVQ $runtime·badreflectcall(SB), AX
JMP AX
#define CALLFN(NAME,MAXSIZE) \
TEXT NAME(SB), WRAPPER, $MAXSIZE-32; \
NO_LOCAL_POINTERS; \
/* copy arguments to stack */ \
MOVQ argptr+16(FP), SI; \
MOVLQZX argsize+24(FP), CX; \
MOVQ SP, DI; \
REP;MOVSB; \
/* call function */ \
MOVQ f+8(FP), DX; \
PCDATA $PCDATA_StackMapIndex, $0; \
CALL (DX); \
/* copy return values back */ \
MOVQ argptr+16(FP), DI; \
MOVLQZX argsize+24(FP), CX; \
MOVLQZX retoffset+28(FP), BX; \
MOVQ SP, SI; \
reflect, runtime: fix crash in GC due to reflect.call + precise GC Given type Outer struct { *Inner ... } the compiler generates the implementation of (*Outer).M dispatching to the embedded Inner. The implementation is logically: func (p *Outer) M() { (p.Inner).M() } but since the only change here is the replacement of one pointer receiver with another, the actual generated code overwrites the original receiver with the p.Inner pointer and then jumps to the M method expecting the *Inner receiver. During reflect.Value.Call, we create an argument frame and the associated data structures to describe it to the garbage collector, populate the frame, call reflect.call to run a function call using that frame, and then copy the results back out of the frame. The reflect.call function does a memmove of the frame structure onto the stack (to set up the inputs), runs the call, and the memmoves the stack back to the frame structure (to preserve the outputs). Originally reflect.call did not distinguish inputs from outputs: both memmoves were for the full stack frame. However, in the case where the called function was one of these wrappers, the rewritten receiver is almost certainly a different type than the original receiver. This is not a problem on the stack, where we use the program counter to determine the type information and understand that during (*Outer).M the receiver is an *Outer while during (*Inner).M the receiver in the same memory word is now an *Inner. But in the statically typed argument frame created by reflect, the receiver is always an *Outer. Copying the modified receiver pointer off the stack into the frame will store an *Inner there, and then if a garbage collection happens to scan that argument frame before it is discarded, it will scan the *Inner memory as if it were an *Outer. If the two have different memory layouts, the collection will intepret the memory incorrectly. Fix by only copying back the results. Fixes #7725. LGTM=khr R=khr CC=dave, golang-codereviews https://golang.org/cl/85180043
2014-04-08 09:11:35 -06:00
ADDQ BX, DI; \
ADDQ BX, SI; \
SUBQ BX, CX; \
REP;MOVSB; \
/* execute write barrier updates */ \
MOVQ argtype+0(FP), DX; \
MOVQ argptr+16(FP), DI; \
MOVLQZX argsize+24(FP), CX; \
MOVLQZX retoffset+28(FP), BX; \
MOVQ DX, 0(SP); \
MOVQ DI, 8(SP); \
MOVQ CX, 16(SP); \
MOVQ BX, 24(SP); \
CALL runtime·callwritebarrier(SB); \
RET
CALLFN(·call32, 32)
CALLFN(·call64, 64)
CALLFN(·call128, 128)
CALLFN(·call256, 256)
CALLFN(·call512, 512)
CALLFN(·call1024, 1024)
CALLFN(·call2048, 2048)
CALLFN(·call4096, 4096)
CALLFN(·call8192, 8192)
CALLFN(·call16384, 16384)
CALLFN(·call32768, 32768)
CALLFN(·call65536, 65536)
CALLFN(·call131072, 131072)
CALLFN(·call262144, 262144)
CALLFN(·call524288, 524288)
CALLFN(·call1048576, 1048576)
CALLFN(·call2097152, 2097152)
CALLFN(·call4194304, 4194304)
CALLFN(·call8388608, 8388608)
CALLFN(·call16777216, 16777216)
CALLFN(·call33554432, 33554432)
CALLFN(·call67108864, 67108864)
CALLFN(·call134217728, 134217728)
CALLFN(·call268435456, 268435456)
CALLFN(·call536870912, 536870912)
CALLFN(·call1073741824, 1073741824)
// bool cas(int32 *val, int32 old, int32 new)
// Atomically:
// if(*val == old){
// *val = new;
// return 1;
2009-01-27 13:03:53 -07:00
// } else
// return 0;
cmd/cc, runtime: convert C compilers to use Go calling convention To date, the C compilers and Go compilers differed only in how values were returned from functions. This made it difficult to call Go from C or C from Go if return values were involved. It also made assembly called from Go and assembly called from C different. This CL changes the C compiler to use the Go conventions, passing results on the stack, after the arguments. [Exception: this does not apply to C ... functions, because you can't know where on the stack the arguments end.] By doing this, the CL makes it possible to rewrite C functions into Go one at a time, without worrying about which languages call that function or which languages it calls. This CL also updates all the assembly files in package runtime to use the new conventions. Argument references of the form 40(SP) have been rewritten to the form name+10(FP) instead, and there are now Go func prototypes for every assembly function called from C or Go. This means that 'go vet runtime' checks effectively every assembly function, and go vet's output was used to automate the bulk of the conversion. Some functions, like seek and nsec on Plan 9, needed to be rewritten. Many assembly routines called from C were reading arguments incorrectly, using MOVL instead of MOVQ or vice versa, especially on the less used systems like openbsd. These were found by go vet and have been corrected too. If we're lucky, this may reduce flakiness on those systems. Tested on: darwin/386 darwin/amd64 linux/arm linux/386 linux/amd64 If this breaks another system, the bug is almost certainly in the sys_$GOOS_$GOARCH.s file, since the rest of the CL is tested by the combination of the above systems. LGTM=dvyukov, iant R=golang-codereviews, 0intro, dave, alex.brainman, dvyukov, iant CC=golang-codereviews, josharian, r https://golang.org/cl/135830043
2014-08-27 09:32:17 -06:00
TEXT runtime·cas(SB), NOSPLIT, $0-17
MOVQ ptr+0(FP), BX
MOVL old+8(FP), AX
MOVL new+12(FP), CX
LOCK
CMPXCHGL CX, 0(BX)
SETEQ ret+16(FP)
RET
2009-01-27 13:03:53 -07:00
// bool runtime·cas64(uint64 *val, uint64 old, uint64 new)
// Atomically:
// if(*val == *old){
// *val = new;
// return 1;
// } else {
// return 0;
// }
cmd/cc, runtime: convert C compilers to use Go calling convention To date, the C compilers and Go compilers differed only in how values were returned from functions. This made it difficult to call Go from C or C from Go if return values were involved. It also made assembly called from Go and assembly called from C different. This CL changes the C compiler to use the Go conventions, passing results on the stack, after the arguments. [Exception: this does not apply to C ... functions, because you can't know where on the stack the arguments end.] By doing this, the CL makes it possible to rewrite C functions into Go one at a time, without worrying about which languages call that function or which languages it calls. This CL also updates all the assembly files in package runtime to use the new conventions. Argument references of the form 40(SP) have been rewritten to the form name+10(FP) instead, and there are now Go func prototypes for every assembly function called from C or Go. This means that 'go vet runtime' checks effectively every assembly function, and go vet's output was used to automate the bulk of the conversion. Some functions, like seek and nsec on Plan 9, needed to be rewritten. Many assembly routines called from C were reading arguments incorrectly, using MOVL instead of MOVQ or vice versa, especially on the less used systems like openbsd. These were found by go vet and have been corrected too. If we're lucky, this may reduce flakiness on those systems. Tested on: darwin/386 darwin/amd64 linux/arm linux/386 linux/amd64 If this breaks another system, the bug is almost certainly in the sys_$GOOS_$GOARCH.s file, since the rest of the CL is tested by the combination of the above systems. LGTM=dvyukov, iant R=golang-codereviews, 0intro, dave, alex.brainman, dvyukov, iant CC=golang-codereviews, josharian, r https://golang.org/cl/135830043
2014-08-27 09:32:17 -06:00
TEXT runtime·cas64(SB), NOSPLIT, $0-25
MOVQ ptr+0(FP), BX
MOVQ old+8(FP), AX
MOVQ new+16(FP), CX
LOCK
CMPXCHGQ CX, 0(BX)
SETEQ ret+24(FP)
RET
TEXT runtime·casuintptr(SB), NOSPLIT, $0-25
JMP runtime·cas64(SB)
TEXT runtime·atomicloaduintptr(SB), NOSPLIT, $0-16
JMP runtime·atomicload64(SB)
TEXT runtime·atomicloaduint(SB), NOSPLIT, $0-16
JMP runtime·atomicload64(SB)
TEXT runtime·atomicstoreuintptr(SB), NOSPLIT, $0-16
JMP runtime·atomicstore64(SB)
// bool casp(void **val, void *old, void *new)
// Atomically:
// if(*val == old){
// *val = new;
// return 1;
// } else
// return 0;
TEXT runtime·casp1(SB), NOSPLIT, $0-25
cmd/cc, runtime: convert C compilers to use Go calling convention To date, the C compilers and Go compilers differed only in how values were returned from functions. This made it difficult to call Go from C or C from Go if return values were involved. It also made assembly called from Go and assembly called from C different. This CL changes the C compiler to use the Go conventions, passing results on the stack, after the arguments. [Exception: this does not apply to C ... functions, because you can't know where on the stack the arguments end.] By doing this, the CL makes it possible to rewrite C functions into Go one at a time, without worrying about which languages call that function or which languages it calls. This CL also updates all the assembly files in package runtime to use the new conventions. Argument references of the form 40(SP) have been rewritten to the form name+10(FP) instead, and there are now Go func prototypes for every assembly function called from C or Go. This means that 'go vet runtime' checks effectively every assembly function, and go vet's output was used to automate the bulk of the conversion. Some functions, like seek and nsec on Plan 9, needed to be rewritten. Many assembly routines called from C were reading arguments incorrectly, using MOVL instead of MOVQ or vice versa, especially on the less used systems like openbsd. These were found by go vet and have been corrected too. If we're lucky, this may reduce flakiness on those systems. Tested on: darwin/386 darwin/amd64 linux/arm linux/386 linux/amd64 If this breaks another system, the bug is almost certainly in the sys_$GOOS_$GOARCH.s file, since the rest of the CL is tested by the combination of the above systems. LGTM=dvyukov, iant R=golang-codereviews, 0intro, dave, alex.brainman, dvyukov, iant CC=golang-codereviews, josharian, r https://golang.org/cl/135830043
2014-08-27 09:32:17 -06:00
MOVQ ptr+0(FP), BX
MOVQ old+8(FP), AX
MOVQ new+16(FP), CX
LOCK
CMPXCHGQ CX, 0(BX)
SETEQ ret+24(FP)
RET
// uint32 xadd(uint32 volatile *val, int32 delta)
// Atomically:
// *val += delta;
// return *val;
cmd/cc, runtime: convert C compilers to use Go calling convention To date, the C compilers and Go compilers differed only in how values were returned from functions. This made it difficult to call Go from C or C from Go if return values were involved. It also made assembly called from Go and assembly called from C different. This CL changes the C compiler to use the Go conventions, passing results on the stack, after the arguments. [Exception: this does not apply to C ... functions, because you can't know where on the stack the arguments end.] By doing this, the CL makes it possible to rewrite C functions into Go one at a time, without worrying about which languages call that function or which languages it calls. This CL also updates all the assembly files in package runtime to use the new conventions. Argument references of the form 40(SP) have been rewritten to the form name+10(FP) instead, and there are now Go func prototypes for every assembly function called from C or Go. This means that 'go vet runtime' checks effectively every assembly function, and go vet's output was used to automate the bulk of the conversion. Some functions, like seek and nsec on Plan 9, needed to be rewritten. Many assembly routines called from C were reading arguments incorrectly, using MOVL instead of MOVQ or vice versa, especially on the less used systems like openbsd. These were found by go vet and have been corrected too. If we're lucky, this may reduce flakiness on those systems. Tested on: darwin/386 darwin/amd64 linux/arm linux/386 linux/amd64 If this breaks another system, the bug is almost certainly in the sys_$GOOS_$GOARCH.s file, since the rest of the CL is tested by the combination of the above systems. LGTM=dvyukov, iant R=golang-codereviews, 0intro, dave, alex.brainman, dvyukov, iant CC=golang-codereviews, josharian, r https://golang.org/cl/135830043
2014-08-27 09:32:17 -06:00
TEXT runtime·xadd(SB), NOSPLIT, $0-20
MOVQ ptr+0(FP), BX
MOVL delta+8(FP), AX
MOVL AX, CX
LOCK
XADDL AX, 0(BX)
ADDL CX, AX
cmd/cc, runtime: convert C compilers to use Go calling convention To date, the C compilers and Go compilers differed only in how values were returned from functions. This made it difficult to call Go from C or C from Go if return values were involved. It also made assembly called from Go and assembly called from C different. This CL changes the C compiler to use the Go conventions, passing results on the stack, after the arguments. [Exception: this does not apply to C ... functions, because you can't know where on the stack the arguments end.] By doing this, the CL makes it possible to rewrite C functions into Go one at a time, without worrying about which languages call that function or which languages it calls. This CL also updates all the assembly files in package runtime to use the new conventions. Argument references of the form 40(SP) have been rewritten to the form name+10(FP) instead, and there are now Go func prototypes for every assembly function called from C or Go. This means that 'go vet runtime' checks effectively every assembly function, and go vet's output was used to automate the bulk of the conversion. Some functions, like seek and nsec on Plan 9, needed to be rewritten. Many assembly routines called from C were reading arguments incorrectly, using MOVL instead of MOVQ or vice versa, especially on the less used systems like openbsd. These were found by go vet and have been corrected too. If we're lucky, this may reduce flakiness on those systems. Tested on: darwin/386 darwin/amd64 linux/arm linux/386 linux/amd64 If this breaks another system, the bug is almost certainly in the sys_$GOOS_$GOARCH.s file, since the rest of the CL is tested by the combination of the above systems. LGTM=dvyukov, iant R=golang-codereviews, 0intro, dave, alex.brainman, dvyukov, iant CC=golang-codereviews, josharian, r https://golang.org/cl/135830043
2014-08-27 09:32:17 -06:00
MOVL AX, ret+16(FP)
RET
cmd/cc, runtime: convert C compilers to use Go calling convention To date, the C compilers and Go compilers differed only in how values were returned from functions. This made it difficult to call Go from C or C from Go if return values were involved. It also made assembly called from Go and assembly called from C different. This CL changes the C compiler to use the Go conventions, passing results on the stack, after the arguments. [Exception: this does not apply to C ... functions, because you can't know where on the stack the arguments end.] By doing this, the CL makes it possible to rewrite C functions into Go one at a time, without worrying about which languages call that function or which languages it calls. This CL also updates all the assembly files in package runtime to use the new conventions. Argument references of the form 40(SP) have been rewritten to the form name+10(FP) instead, and there are now Go func prototypes for every assembly function called from C or Go. This means that 'go vet runtime' checks effectively every assembly function, and go vet's output was used to automate the bulk of the conversion. Some functions, like seek and nsec on Plan 9, needed to be rewritten. Many assembly routines called from C were reading arguments incorrectly, using MOVL instead of MOVQ or vice versa, especially on the less used systems like openbsd. These were found by go vet and have been corrected too. If we're lucky, this may reduce flakiness on those systems. Tested on: darwin/386 darwin/amd64 linux/arm linux/386 linux/amd64 If this breaks another system, the bug is almost certainly in the sys_$GOOS_$GOARCH.s file, since the rest of the CL is tested by the combination of the above systems. LGTM=dvyukov, iant R=golang-codereviews, 0intro, dave, alex.brainman, dvyukov, iant CC=golang-codereviews, josharian, r https://golang.org/cl/135830043
2014-08-27 09:32:17 -06:00
TEXT runtime·xadd64(SB), NOSPLIT, $0-24
MOVQ ptr+0(FP), BX
MOVQ delta+8(FP), AX
MOVQ AX, CX
LOCK
XADDQ AX, 0(BX)
ADDQ CX, AX
cmd/cc, runtime: convert C compilers to use Go calling convention To date, the C compilers and Go compilers differed only in how values were returned from functions. This made it difficult to call Go from C or C from Go if return values were involved. It also made assembly called from Go and assembly called from C different. This CL changes the C compiler to use the Go conventions, passing results on the stack, after the arguments. [Exception: this does not apply to C ... functions, because you can't know where on the stack the arguments end.] By doing this, the CL makes it possible to rewrite C functions into Go one at a time, without worrying about which languages call that function or which languages it calls. This CL also updates all the assembly files in package runtime to use the new conventions. Argument references of the form 40(SP) have been rewritten to the form name+10(FP) instead, and there are now Go func prototypes for every assembly function called from C or Go. This means that 'go vet runtime' checks effectively every assembly function, and go vet's output was used to automate the bulk of the conversion. Some functions, like seek and nsec on Plan 9, needed to be rewritten. Many assembly routines called from C were reading arguments incorrectly, using MOVL instead of MOVQ or vice versa, especially on the less used systems like openbsd. These were found by go vet and have been corrected too. If we're lucky, this may reduce flakiness on those systems. Tested on: darwin/386 darwin/amd64 linux/arm linux/386 linux/amd64 If this breaks another system, the bug is almost certainly in the sys_$GOOS_$GOARCH.s file, since the rest of the CL is tested by the combination of the above systems. LGTM=dvyukov, iant R=golang-codereviews, 0intro, dave, alex.brainman, dvyukov, iant CC=golang-codereviews, josharian, r https://golang.org/cl/135830043
2014-08-27 09:32:17 -06:00
MOVQ AX, ret+16(FP)
RET
TEXT runtime·xadduintptr(SB), NOSPLIT, $0-24
JMP runtime·xadd64(SB)
cmd/cc, runtime: convert C compilers to use Go calling convention To date, the C compilers and Go compilers differed only in how values were returned from functions. This made it difficult to call Go from C or C from Go if return values were involved. It also made assembly called from Go and assembly called from C different. This CL changes the C compiler to use the Go conventions, passing results on the stack, after the arguments. [Exception: this does not apply to C ... functions, because you can't know where on the stack the arguments end.] By doing this, the CL makes it possible to rewrite C functions into Go one at a time, without worrying about which languages call that function or which languages it calls. This CL also updates all the assembly files in package runtime to use the new conventions. Argument references of the form 40(SP) have been rewritten to the form name+10(FP) instead, and there are now Go func prototypes for every assembly function called from C or Go. This means that 'go vet runtime' checks effectively every assembly function, and go vet's output was used to automate the bulk of the conversion. Some functions, like seek and nsec on Plan 9, needed to be rewritten. Many assembly routines called from C were reading arguments incorrectly, using MOVL instead of MOVQ or vice versa, especially on the less used systems like openbsd. These were found by go vet and have been corrected too. If we're lucky, this may reduce flakiness on those systems. Tested on: darwin/386 darwin/amd64 linux/arm linux/386 linux/amd64 If this breaks another system, the bug is almost certainly in the sys_$GOOS_$GOARCH.s file, since the rest of the CL is tested by the combination of the above systems. LGTM=dvyukov, iant R=golang-codereviews, 0intro, dave, alex.brainman, dvyukov, iant CC=golang-codereviews, josharian, r https://golang.org/cl/135830043
2014-08-27 09:32:17 -06:00
TEXT runtime·xchg(SB), NOSPLIT, $0-20
MOVQ ptr+0(FP), BX
MOVL new+8(FP), AX
runtime: improve Linux mutex The implementation is hybrid active/passive spin/blocking mutex. The design minimizes amount of context switches and futex calls. The idea is that all critical sections in runtime are intentially small, so pure blocking mutex behaves badly causing a lot of context switches, thread parking/unparking and kernel calls. Note that some synthetic benchmarks become somewhat slower, that's due to increased contention on other data structures, it should not affect programs that do any real work. On 2 x Intel E5620, 8 HT cores, 2.4GHz benchmark old ns/op new ns/op delta BenchmarkSelectContended 521.00 503.00 -3.45% BenchmarkSelectContended-2 661.00 320.00 -51.59% BenchmarkSelectContended-4 1139.00 629.00 -44.78% BenchmarkSelectContended-8 2870.00 878.00 -69.41% BenchmarkSelectContended-16 5276.00 818.00 -84.50% BenchmarkChanContended 112.00 103.00 -8.04% BenchmarkChanContended-2 631.00 174.00 -72.42% BenchmarkChanContended-4 682.00 272.00 -60.12% BenchmarkChanContended-8 1601.00 520.00 -67.52% BenchmarkChanContended-16 3100.00 372.00 -88.00% BenchmarkChanSync 253.00 239.00 -5.53% BenchmarkChanSync-2 5030.00 4648.00 -7.59% BenchmarkChanSync-4 4826.00 4694.00 -2.74% BenchmarkChanSync-8 4778.00 4713.00 -1.36% BenchmarkChanSync-16 5289.00 4710.00 -10.95% BenchmarkChanProdCons0 273.00 254.00 -6.96% BenchmarkChanProdCons0-2 599.00 400.00 -33.22% BenchmarkChanProdCons0-4 1168.00 659.00 -43.58% BenchmarkChanProdCons0-8 2831.00 1057.00 -62.66% BenchmarkChanProdCons0-16 4197.00 1037.00 -75.29% BenchmarkChanProdCons10 150.00 140.00 -6.67% BenchmarkChanProdCons10-2 607.00 268.00 -55.85% BenchmarkChanProdCons10-4 1137.00 404.00 -64.47% BenchmarkChanProdCons10-8 2115.00 828.00 -60.85% BenchmarkChanProdCons10-16 4283.00 855.00 -80.04% BenchmarkChanProdCons100 117.00 110.00 -5.98% BenchmarkChanProdCons100-2 558.00 218.00 -60.93% BenchmarkChanProdCons100-4 722.00 287.00 -60.25% BenchmarkChanProdCons100-8 1840.00 431.00 -76.58% BenchmarkChanProdCons100-16 3394.00 448.00 -86.80% BenchmarkChanProdConsWork0 2014.00 1996.00 -0.89% BenchmarkChanProdConsWork0-2 1207.00 1127.00 -6.63% BenchmarkChanProdConsWork0-4 1913.00 611.00 -68.06% BenchmarkChanProdConsWork0-8 3016.00 949.00 -68.53% BenchmarkChanProdConsWork0-16 4320.00 1154.00 -73.29% BenchmarkChanProdConsWork10 1906.00 1897.00 -0.47% BenchmarkChanProdConsWork10-2 1123.00 1033.00 -8.01% BenchmarkChanProdConsWork10-4 1076.00 571.00 -46.93% BenchmarkChanProdConsWork10-8 2748.00 1096.00 -60.12% BenchmarkChanProdConsWork10-16 4600.00 1105.00 -75.98% BenchmarkChanProdConsWork100 1884.00 1852.00 -1.70% BenchmarkChanProdConsWork100-2 1235.00 1146.00 -7.21% BenchmarkChanProdConsWork100-4 1217.00 619.00 -49.14% BenchmarkChanProdConsWork100-8 1534.00 509.00 -66.82% BenchmarkChanProdConsWork100-16 4126.00 918.00 -77.75% BenchmarkSyscall 34.40 33.30 -3.20% BenchmarkSyscall-2 160.00 121.00 -24.38% BenchmarkSyscall-4 131.00 136.00 +3.82% BenchmarkSyscall-8 139.00 131.00 -5.76% BenchmarkSyscall-16 161.00 168.00 +4.35% BenchmarkSyscallWork 950.00 950.00 +0.00% BenchmarkSyscallWork-2 481.00 480.00 -0.21% BenchmarkSyscallWork-4 268.00 270.00 +0.75% BenchmarkSyscallWork-8 156.00 169.00 +8.33% BenchmarkSyscallWork-16 188.00 184.00 -2.13% BenchmarkSemaSyntNonblock 36.40 35.60 -2.20% BenchmarkSemaSyntNonblock-2 81.40 45.10 -44.59% BenchmarkSemaSyntNonblock-4 126.00 108.00 -14.29% BenchmarkSemaSyntNonblock-8 112.00 112.00 +0.00% BenchmarkSemaSyntNonblock-16 110.00 112.00 +1.82% BenchmarkSemaSyntBlock 35.30 35.30 +0.00% BenchmarkSemaSyntBlock-2 118.00 124.00 +5.08% BenchmarkSemaSyntBlock-4 105.00 108.00 +2.86% BenchmarkSemaSyntBlock-8 101.00 111.00 +9.90% BenchmarkSemaSyntBlock-16 112.00 118.00 +5.36% BenchmarkSemaWorkNonblock 810.00 811.00 +0.12% BenchmarkSemaWorkNonblock-2 476.00 414.00 -13.03% BenchmarkSemaWorkNonblock-4 238.00 228.00 -4.20% BenchmarkSemaWorkNonblock-8 140.00 126.00 -10.00% BenchmarkSemaWorkNonblock-16 117.00 116.00 -0.85% BenchmarkSemaWorkBlock 810.00 811.00 +0.12% BenchmarkSemaWorkBlock-2 454.00 466.00 +2.64% BenchmarkSemaWorkBlock-4 243.00 241.00 -0.82% BenchmarkSemaWorkBlock-8 145.00 137.00 -5.52% BenchmarkSemaWorkBlock-16 132.00 123.00 -6.82% BenchmarkContendedSemaphore 123.00 102.00 -17.07% BenchmarkContendedSemaphore-2 34.80 34.90 +0.29% BenchmarkContendedSemaphore-4 34.70 34.80 +0.29% BenchmarkContendedSemaphore-8 34.70 34.70 +0.00% BenchmarkContendedSemaphore-16 34.80 34.70 -0.29% BenchmarkMutex 26.80 26.00 -2.99% BenchmarkMutex-2 108.00 45.20 -58.15% BenchmarkMutex-4 103.00 127.00 +23.30% BenchmarkMutex-8 109.00 147.00 +34.86% BenchmarkMutex-16 102.00 152.00 +49.02% BenchmarkMutexSlack 27.00 26.90 -0.37% BenchmarkMutexSlack-2 149.00 165.00 +10.74% BenchmarkMutexSlack-4 121.00 209.00 +72.73% BenchmarkMutexSlack-8 101.00 158.00 +56.44% BenchmarkMutexSlack-16 97.00 129.00 +32.99% BenchmarkMutexWork 792.00 794.00 +0.25% BenchmarkMutexWork-2 407.00 409.00 +0.49% BenchmarkMutexWork-4 220.00 209.00 -5.00% BenchmarkMutexWork-8 267.00 160.00 -40.07% BenchmarkMutexWork-16 315.00 300.00 -4.76% BenchmarkMutexWorkSlack 792.00 793.00 +0.13% BenchmarkMutexWorkSlack-2 406.00 404.00 -0.49% BenchmarkMutexWorkSlack-4 225.00 212.00 -5.78% BenchmarkMutexWorkSlack-8 268.00 136.00 -49.25% BenchmarkMutexWorkSlack-16 300.00 300.00 +0.00% BenchmarkRWMutexWrite100 27.10 27.00 -0.37% BenchmarkRWMutexWrite100-2 33.10 40.80 +23.26% BenchmarkRWMutexWrite100-4 113.00 88.10 -22.04% BenchmarkRWMutexWrite100-8 119.00 95.30 -19.92% BenchmarkRWMutexWrite100-16 148.00 109.00 -26.35% BenchmarkRWMutexWrite10 29.60 29.40 -0.68% BenchmarkRWMutexWrite10-2 111.00 61.40 -44.68% BenchmarkRWMutexWrite10-4 270.00 208.00 -22.96% BenchmarkRWMutexWrite10-8 204.00 185.00 -9.31% BenchmarkRWMutexWrite10-16 261.00 190.00 -27.20% BenchmarkRWMutexWorkWrite100 1040.00 1036.00 -0.38% BenchmarkRWMutexWorkWrite100-2 593.00 580.00 -2.19% BenchmarkRWMutexWorkWrite100-4 470.00 365.00 -22.34% BenchmarkRWMutexWorkWrite100-8 468.00 289.00 -38.25% BenchmarkRWMutexWorkWrite100-16 604.00 374.00 -38.08% BenchmarkRWMutexWorkWrite10 951.00 951.00 +0.00% BenchmarkRWMutexWorkWrite10-2 1001.00 928.00 -7.29% BenchmarkRWMutexWorkWrite10-4 1555.00 1006.00 -35.31% BenchmarkRWMutexWorkWrite10-8 2085.00 1171.00 -43.84% BenchmarkRWMutexWorkWrite10-16 2082.00 1614.00 -22.48% R=rsc, iant, msolo, fw, iant CC=golang-dev https://golang.org/cl/4711045
2011-07-29 10:44:06 -06:00
XCHGL AX, 0(BX)
cmd/cc, runtime: convert C compilers to use Go calling convention To date, the C compilers and Go compilers differed only in how values were returned from functions. This made it difficult to call Go from C or C from Go if return values were involved. It also made assembly called from Go and assembly called from C different. This CL changes the C compiler to use the Go conventions, passing results on the stack, after the arguments. [Exception: this does not apply to C ... functions, because you can't know where on the stack the arguments end.] By doing this, the CL makes it possible to rewrite C functions into Go one at a time, without worrying about which languages call that function or which languages it calls. This CL also updates all the assembly files in package runtime to use the new conventions. Argument references of the form 40(SP) have been rewritten to the form name+10(FP) instead, and there are now Go func prototypes for every assembly function called from C or Go. This means that 'go vet runtime' checks effectively every assembly function, and go vet's output was used to automate the bulk of the conversion. Some functions, like seek and nsec on Plan 9, needed to be rewritten. Many assembly routines called from C were reading arguments incorrectly, using MOVL instead of MOVQ or vice versa, especially on the less used systems like openbsd. These were found by go vet and have been corrected too. If we're lucky, this may reduce flakiness on those systems. Tested on: darwin/386 darwin/amd64 linux/arm linux/386 linux/amd64 If this breaks another system, the bug is almost certainly in the sys_$GOOS_$GOARCH.s file, since the rest of the CL is tested by the combination of the above systems. LGTM=dvyukov, iant R=golang-codereviews, 0intro, dave, alex.brainman, dvyukov, iant CC=golang-codereviews, josharian, r https://golang.org/cl/135830043
2014-08-27 09:32:17 -06:00
MOVL AX, ret+16(FP)
runtime: improve Linux mutex The implementation is hybrid active/passive spin/blocking mutex. The design minimizes amount of context switches and futex calls. The idea is that all critical sections in runtime are intentially small, so pure blocking mutex behaves badly causing a lot of context switches, thread parking/unparking and kernel calls. Note that some synthetic benchmarks become somewhat slower, that's due to increased contention on other data structures, it should not affect programs that do any real work. On 2 x Intel E5620, 8 HT cores, 2.4GHz benchmark old ns/op new ns/op delta BenchmarkSelectContended 521.00 503.00 -3.45% BenchmarkSelectContended-2 661.00 320.00 -51.59% BenchmarkSelectContended-4 1139.00 629.00 -44.78% BenchmarkSelectContended-8 2870.00 878.00 -69.41% BenchmarkSelectContended-16 5276.00 818.00 -84.50% BenchmarkChanContended 112.00 103.00 -8.04% BenchmarkChanContended-2 631.00 174.00 -72.42% BenchmarkChanContended-4 682.00 272.00 -60.12% BenchmarkChanContended-8 1601.00 520.00 -67.52% BenchmarkChanContended-16 3100.00 372.00 -88.00% BenchmarkChanSync 253.00 239.00 -5.53% BenchmarkChanSync-2 5030.00 4648.00 -7.59% BenchmarkChanSync-4 4826.00 4694.00 -2.74% BenchmarkChanSync-8 4778.00 4713.00 -1.36% BenchmarkChanSync-16 5289.00 4710.00 -10.95% BenchmarkChanProdCons0 273.00 254.00 -6.96% BenchmarkChanProdCons0-2 599.00 400.00 -33.22% BenchmarkChanProdCons0-4 1168.00 659.00 -43.58% BenchmarkChanProdCons0-8 2831.00 1057.00 -62.66% BenchmarkChanProdCons0-16 4197.00 1037.00 -75.29% BenchmarkChanProdCons10 150.00 140.00 -6.67% BenchmarkChanProdCons10-2 607.00 268.00 -55.85% BenchmarkChanProdCons10-4 1137.00 404.00 -64.47% BenchmarkChanProdCons10-8 2115.00 828.00 -60.85% BenchmarkChanProdCons10-16 4283.00 855.00 -80.04% BenchmarkChanProdCons100 117.00 110.00 -5.98% BenchmarkChanProdCons100-2 558.00 218.00 -60.93% BenchmarkChanProdCons100-4 722.00 287.00 -60.25% BenchmarkChanProdCons100-8 1840.00 431.00 -76.58% BenchmarkChanProdCons100-16 3394.00 448.00 -86.80% BenchmarkChanProdConsWork0 2014.00 1996.00 -0.89% BenchmarkChanProdConsWork0-2 1207.00 1127.00 -6.63% BenchmarkChanProdConsWork0-4 1913.00 611.00 -68.06% BenchmarkChanProdConsWork0-8 3016.00 949.00 -68.53% BenchmarkChanProdConsWork0-16 4320.00 1154.00 -73.29% BenchmarkChanProdConsWork10 1906.00 1897.00 -0.47% BenchmarkChanProdConsWork10-2 1123.00 1033.00 -8.01% BenchmarkChanProdConsWork10-4 1076.00 571.00 -46.93% BenchmarkChanProdConsWork10-8 2748.00 1096.00 -60.12% BenchmarkChanProdConsWork10-16 4600.00 1105.00 -75.98% BenchmarkChanProdConsWork100 1884.00 1852.00 -1.70% BenchmarkChanProdConsWork100-2 1235.00 1146.00 -7.21% BenchmarkChanProdConsWork100-4 1217.00 619.00 -49.14% BenchmarkChanProdConsWork100-8 1534.00 509.00 -66.82% BenchmarkChanProdConsWork100-16 4126.00 918.00 -77.75% BenchmarkSyscall 34.40 33.30 -3.20% BenchmarkSyscall-2 160.00 121.00 -24.38% BenchmarkSyscall-4 131.00 136.00 +3.82% BenchmarkSyscall-8 139.00 131.00 -5.76% BenchmarkSyscall-16 161.00 168.00 +4.35% BenchmarkSyscallWork 950.00 950.00 +0.00% BenchmarkSyscallWork-2 481.00 480.00 -0.21% BenchmarkSyscallWork-4 268.00 270.00 +0.75% BenchmarkSyscallWork-8 156.00 169.00 +8.33% BenchmarkSyscallWork-16 188.00 184.00 -2.13% BenchmarkSemaSyntNonblock 36.40 35.60 -2.20% BenchmarkSemaSyntNonblock-2 81.40 45.10 -44.59% BenchmarkSemaSyntNonblock-4 126.00 108.00 -14.29% BenchmarkSemaSyntNonblock-8 112.00 112.00 +0.00% BenchmarkSemaSyntNonblock-16 110.00 112.00 +1.82% BenchmarkSemaSyntBlock 35.30 35.30 +0.00% BenchmarkSemaSyntBlock-2 118.00 124.00 +5.08% BenchmarkSemaSyntBlock-4 105.00 108.00 +2.86% BenchmarkSemaSyntBlock-8 101.00 111.00 +9.90% BenchmarkSemaSyntBlock-16 112.00 118.00 +5.36% BenchmarkSemaWorkNonblock 810.00 811.00 +0.12% BenchmarkSemaWorkNonblock-2 476.00 414.00 -13.03% BenchmarkSemaWorkNonblock-4 238.00 228.00 -4.20% BenchmarkSemaWorkNonblock-8 140.00 126.00 -10.00% BenchmarkSemaWorkNonblock-16 117.00 116.00 -0.85% BenchmarkSemaWorkBlock 810.00 811.00 +0.12% BenchmarkSemaWorkBlock-2 454.00 466.00 +2.64% BenchmarkSemaWorkBlock-4 243.00 241.00 -0.82% BenchmarkSemaWorkBlock-8 145.00 137.00 -5.52% BenchmarkSemaWorkBlock-16 132.00 123.00 -6.82% BenchmarkContendedSemaphore 123.00 102.00 -17.07% BenchmarkContendedSemaphore-2 34.80 34.90 +0.29% BenchmarkContendedSemaphore-4 34.70 34.80 +0.29% BenchmarkContendedSemaphore-8 34.70 34.70 +0.00% BenchmarkContendedSemaphore-16 34.80 34.70 -0.29% BenchmarkMutex 26.80 26.00 -2.99% BenchmarkMutex-2 108.00 45.20 -58.15% BenchmarkMutex-4 103.00 127.00 +23.30% BenchmarkMutex-8 109.00 147.00 +34.86% BenchmarkMutex-16 102.00 152.00 +49.02% BenchmarkMutexSlack 27.00 26.90 -0.37% BenchmarkMutexSlack-2 149.00 165.00 +10.74% BenchmarkMutexSlack-4 121.00 209.00 +72.73% BenchmarkMutexSlack-8 101.00 158.00 +56.44% BenchmarkMutexSlack-16 97.00 129.00 +32.99% BenchmarkMutexWork 792.00 794.00 +0.25% BenchmarkMutexWork-2 407.00 409.00 +0.49% BenchmarkMutexWork-4 220.00 209.00 -5.00% BenchmarkMutexWork-8 267.00 160.00 -40.07% BenchmarkMutexWork-16 315.00 300.00 -4.76% BenchmarkMutexWorkSlack 792.00 793.00 +0.13% BenchmarkMutexWorkSlack-2 406.00 404.00 -0.49% BenchmarkMutexWorkSlack-4 225.00 212.00 -5.78% BenchmarkMutexWorkSlack-8 268.00 136.00 -49.25% BenchmarkMutexWorkSlack-16 300.00 300.00 +0.00% BenchmarkRWMutexWrite100 27.10 27.00 -0.37% BenchmarkRWMutexWrite100-2 33.10 40.80 +23.26% BenchmarkRWMutexWrite100-4 113.00 88.10 -22.04% BenchmarkRWMutexWrite100-8 119.00 95.30 -19.92% BenchmarkRWMutexWrite100-16 148.00 109.00 -26.35% BenchmarkRWMutexWrite10 29.60 29.40 -0.68% BenchmarkRWMutexWrite10-2 111.00 61.40 -44.68% BenchmarkRWMutexWrite10-4 270.00 208.00 -22.96% BenchmarkRWMutexWrite10-8 204.00 185.00 -9.31% BenchmarkRWMutexWrite10-16 261.00 190.00 -27.20% BenchmarkRWMutexWorkWrite100 1040.00 1036.00 -0.38% BenchmarkRWMutexWorkWrite100-2 593.00 580.00 -2.19% BenchmarkRWMutexWorkWrite100-4 470.00 365.00 -22.34% BenchmarkRWMutexWorkWrite100-8 468.00 289.00 -38.25% BenchmarkRWMutexWorkWrite100-16 604.00 374.00 -38.08% BenchmarkRWMutexWorkWrite10 951.00 951.00 +0.00% BenchmarkRWMutexWorkWrite10-2 1001.00 928.00 -7.29% BenchmarkRWMutexWorkWrite10-4 1555.00 1006.00 -35.31% BenchmarkRWMutexWorkWrite10-8 2085.00 1171.00 -43.84% BenchmarkRWMutexWorkWrite10-16 2082.00 1614.00 -22.48% R=rsc, iant, msolo, fw, iant CC=golang-dev https://golang.org/cl/4711045
2011-07-29 10:44:06 -06:00
RET
cmd/cc, runtime: convert C compilers to use Go calling convention To date, the C compilers and Go compilers differed only in how values were returned from functions. This made it difficult to call Go from C or C from Go if return values were involved. It also made assembly called from Go and assembly called from C different. This CL changes the C compiler to use the Go conventions, passing results on the stack, after the arguments. [Exception: this does not apply to C ... functions, because you can't know where on the stack the arguments end.] By doing this, the CL makes it possible to rewrite C functions into Go one at a time, without worrying about which languages call that function or which languages it calls. This CL also updates all the assembly files in package runtime to use the new conventions. Argument references of the form 40(SP) have been rewritten to the form name+10(FP) instead, and there are now Go func prototypes for every assembly function called from C or Go. This means that 'go vet runtime' checks effectively every assembly function, and go vet's output was used to automate the bulk of the conversion. Some functions, like seek and nsec on Plan 9, needed to be rewritten. Many assembly routines called from C were reading arguments incorrectly, using MOVL instead of MOVQ or vice versa, especially on the less used systems like openbsd. These were found by go vet and have been corrected too. If we're lucky, this may reduce flakiness on those systems. Tested on: darwin/386 darwin/amd64 linux/arm linux/386 linux/amd64 If this breaks another system, the bug is almost certainly in the sys_$GOOS_$GOARCH.s file, since the rest of the CL is tested by the combination of the above systems. LGTM=dvyukov, iant R=golang-codereviews, 0intro, dave, alex.brainman, dvyukov, iant CC=golang-codereviews, josharian, r https://golang.org/cl/135830043
2014-08-27 09:32:17 -06:00
TEXT runtime·xchg64(SB), NOSPLIT, $0-24
MOVQ ptr+0(FP), BX
MOVQ new+8(FP), AX
XCHGQ AX, 0(BX)
cmd/cc, runtime: convert C compilers to use Go calling convention To date, the C compilers and Go compilers differed only in how values were returned from functions. This made it difficult to call Go from C or C from Go if return values were involved. It also made assembly called from Go and assembly called from C different. This CL changes the C compiler to use the Go conventions, passing results on the stack, after the arguments. [Exception: this does not apply to C ... functions, because you can't know where on the stack the arguments end.] By doing this, the CL makes it possible to rewrite C functions into Go one at a time, without worrying about which languages call that function or which languages it calls. This CL also updates all the assembly files in package runtime to use the new conventions. Argument references of the form 40(SP) have been rewritten to the form name+10(FP) instead, and there are now Go func prototypes for every assembly function called from C or Go. This means that 'go vet runtime' checks effectively every assembly function, and go vet's output was used to automate the bulk of the conversion. Some functions, like seek and nsec on Plan 9, needed to be rewritten. Many assembly routines called from C were reading arguments incorrectly, using MOVL instead of MOVQ or vice versa, especially on the less used systems like openbsd. These were found by go vet and have been corrected too. If we're lucky, this may reduce flakiness on those systems. Tested on: darwin/386 darwin/amd64 linux/arm linux/386 linux/amd64 If this breaks another system, the bug is almost certainly in the sys_$GOOS_$GOARCH.s file, since the rest of the CL is tested by the combination of the above systems. LGTM=dvyukov, iant R=golang-codereviews, 0intro, dave, alex.brainman, dvyukov, iant CC=golang-codereviews, josharian, r https://golang.org/cl/135830043
2014-08-27 09:32:17 -06:00
MOVQ AX, ret+16(FP)
RET
TEXT runtime·xchgp1(SB), NOSPLIT, $0-24
cmd/cc, runtime: convert C compilers to use Go calling convention To date, the C compilers and Go compilers differed only in how values were returned from functions. This made it difficult to call Go from C or C from Go if return values were involved. It also made assembly called from Go and assembly called from C different. This CL changes the C compiler to use the Go conventions, passing results on the stack, after the arguments. [Exception: this does not apply to C ... functions, because you can't know where on the stack the arguments end.] By doing this, the CL makes it possible to rewrite C functions into Go one at a time, without worrying about which languages call that function or which languages it calls. This CL also updates all the assembly files in package runtime to use the new conventions. Argument references of the form 40(SP) have been rewritten to the form name+10(FP) instead, and there are now Go func prototypes for every assembly function called from C or Go. This means that 'go vet runtime' checks effectively every assembly function, and go vet's output was used to automate the bulk of the conversion. Some functions, like seek and nsec on Plan 9, needed to be rewritten. Many assembly routines called from C were reading arguments incorrectly, using MOVL instead of MOVQ or vice versa, especially on the less used systems like openbsd. These were found by go vet and have been corrected too. If we're lucky, this may reduce flakiness on those systems. Tested on: darwin/386 darwin/amd64 linux/arm linux/386 linux/amd64 If this breaks another system, the bug is almost certainly in the sys_$GOOS_$GOARCH.s file, since the rest of the CL is tested by the combination of the above systems. LGTM=dvyukov, iant R=golang-codereviews, 0intro, dave, alex.brainman, dvyukov, iant CC=golang-codereviews, josharian, r https://golang.org/cl/135830043
2014-08-27 09:32:17 -06:00
MOVQ ptr+0(FP), BX
MOVQ new+8(FP), AX
XCHGQ AX, 0(BX)
cmd/cc, runtime: convert C compilers to use Go calling convention To date, the C compilers and Go compilers differed only in how values were returned from functions. This made it difficult to call Go from C or C from Go if return values were involved. It also made assembly called from Go and assembly called from C different. This CL changes the C compiler to use the Go conventions, passing results on the stack, after the arguments. [Exception: this does not apply to C ... functions, because you can't know where on the stack the arguments end.] By doing this, the CL makes it possible to rewrite C functions into Go one at a time, without worrying about which languages call that function or which languages it calls. This CL also updates all the assembly files in package runtime to use the new conventions. Argument references of the form 40(SP) have been rewritten to the form name+10(FP) instead, and there are now Go func prototypes for every assembly function called from C or Go. This means that 'go vet runtime' checks effectively every assembly function, and go vet's output was used to automate the bulk of the conversion. Some functions, like seek and nsec on Plan 9, needed to be rewritten. Many assembly routines called from C were reading arguments incorrectly, using MOVL instead of MOVQ or vice versa, especially on the less used systems like openbsd. These were found by go vet and have been corrected too. If we're lucky, this may reduce flakiness on those systems. Tested on: darwin/386 darwin/amd64 linux/arm linux/386 linux/amd64 If this breaks another system, the bug is almost certainly in the sys_$GOOS_$GOARCH.s file, since the rest of the CL is tested by the combination of the above systems. LGTM=dvyukov, iant R=golang-codereviews, 0intro, dave, alex.brainman, dvyukov, iant CC=golang-codereviews, josharian, r https://golang.org/cl/135830043
2014-08-27 09:32:17 -06:00
MOVQ AX, ret+16(FP)
RET
TEXT runtime·xchguintptr(SB), NOSPLIT, $0-24
JMP runtime·xchg64(SB)
TEXT runtime·procyield(SB),NOSPLIT,$0-0
cmd/cc, runtime: convert C compilers to use Go calling convention To date, the C compilers and Go compilers differed only in how values were returned from functions. This made it difficult to call Go from C or C from Go if return values were involved. It also made assembly called from Go and assembly called from C different. This CL changes the C compiler to use the Go conventions, passing results on the stack, after the arguments. [Exception: this does not apply to C ... functions, because you can't know where on the stack the arguments end.] By doing this, the CL makes it possible to rewrite C functions into Go one at a time, without worrying about which languages call that function or which languages it calls. This CL also updates all the assembly files in package runtime to use the new conventions. Argument references of the form 40(SP) have been rewritten to the form name+10(FP) instead, and there are now Go func prototypes for every assembly function called from C or Go. This means that 'go vet runtime' checks effectively every assembly function, and go vet's output was used to automate the bulk of the conversion. Some functions, like seek and nsec on Plan 9, needed to be rewritten. Many assembly routines called from C were reading arguments incorrectly, using MOVL instead of MOVQ or vice versa, especially on the less used systems like openbsd. These were found by go vet and have been corrected too. If we're lucky, this may reduce flakiness on those systems. Tested on: darwin/386 darwin/amd64 linux/arm linux/386 linux/amd64 If this breaks another system, the bug is almost certainly in the sys_$GOOS_$GOARCH.s file, since the rest of the CL is tested by the combination of the above systems. LGTM=dvyukov, iant R=golang-codereviews, 0intro, dave, alex.brainman, dvyukov, iant CC=golang-codereviews, josharian, r https://golang.org/cl/135830043
2014-08-27 09:32:17 -06:00
MOVL cycles+0(FP), AX
runtime: improve Linux mutex The implementation is hybrid active/passive spin/blocking mutex. The design minimizes amount of context switches and futex calls. The idea is that all critical sections in runtime are intentially small, so pure blocking mutex behaves badly causing a lot of context switches, thread parking/unparking and kernel calls. Note that some synthetic benchmarks become somewhat slower, that's due to increased contention on other data structures, it should not affect programs that do any real work. On 2 x Intel E5620, 8 HT cores, 2.4GHz benchmark old ns/op new ns/op delta BenchmarkSelectContended 521.00 503.00 -3.45% BenchmarkSelectContended-2 661.00 320.00 -51.59% BenchmarkSelectContended-4 1139.00 629.00 -44.78% BenchmarkSelectContended-8 2870.00 878.00 -69.41% BenchmarkSelectContended-16 5276.00 818.00 -84.50% BenchmarkChanContended 112.00 103.00 -8.04% BenchmarkChanContended-2 631.00 174.00 -72.42% BenchmarkChanContended-4 682.00 272.00 -60.12% BenchmarkChanContended-8 1601.00 520.00 -67.52% BenchmarkChanContended-16 3100.00 372.00 -88.00% BenchmarkChanSync 253.00 239.00 -5.53% BenchmarkChanSync-2 5030.00 4648.00 -7.59% BenchmarkChanSync-4 4826.00 4694.00 -2.74% BenchmarkChanSync-8 4778.00 4713.00 -1.36% BenchmarkChanSync-16 5289.00 4710.00 -10.95% BenchmarkChanProdCons0 273.00 254.00 -6.96% BenchmarkChanProdCons0-2 599.00 400.00 -33.22% BenchmarkChanProdCons0-4 1168.00 659.00 -43.58% BenchmarkChanProdCons0-8 2831.00 1057.00 -62.66% BenchmarkChanProdCons0-16 4197.00 1037.00 -75.29% BenchmarkChanProdCons10 150.00 140.00 -6.67% BenchmarkChanProdCons10-2 607.00 268.00 -55.85% BenchmarkChanProdCons10-4 1137.00 404.00 -64.47% BenchmarkChanProdCons10-8 2115.00 828.00 -60.85% BenchmarkChanProdCons10-16 4283.00 855.00 -80.04% BenchmarkChanProdCons100 117.00 110.00 -5.98% BenchmarkChanProdCons100-2 558.00 218.00 -60.93% BenchmarkChanProdCons100-4 722.00 287.00 -60.25% BenchmarkChanProdCons100-8 1840.00 431.00 -76.58% BenchmarkChanProdCons100-16 3394.00 448.00 -86.80% BenchmarkChanProdConsWork0 2014.00 1996.00 -0.89% BenchmarkChanProdConsWork0-2 1207.00 1127.00 -6.63% BenchmarkChanProdConsWork0-4 1913.00 611.00 -68.06% BenchmarkChanProdConsWork0-8 3016.00 949.00 -68.53% BenchmarkChanProdConsWork0-16 4320.00 1154.00 -73.29% BenchmarkChanProdConsWork10 1906.00 1897.00 -0.47% BenchmarkChanProdConsWork10-2 1123.00 1033.00 -8.01% BenchmarkChanProdConsWork10-4 1076.00 571.00 -46.93% BenchmarkChanProdConsWork10-8 2748.00 1096.00 -60.12% BenchmarkChanProdConsWork10-16 4600.00 1105.00 -75.98% BenchmarkChanProdConsWork100 1884.00 1852.00 -1.70% BenchmarkChanProdConsWork100-2 1235.00 1146.00 -7.21% BenchmarkChanProdConsWork100-4 1217.00 619.00 -49.14% BenchmarkChanProdConsWork100-8 1534.00 509.00 -66.82% BenchmarkChanProdConsWork100-16 4126.00 918.00 -77.75% BenchmarkSyscall 34.40 33.30 -3.20% BenchmarkSyscall-2 160.00 121.00 -24.38% BenchmarkSyscall-4 131.00 136.00 +3.82% BenchmarkSyscall-8 139.00 131.00 -5.76% BenchmarkSyscall-16 161.00 168.00 +4.35% BenchmarkSyscallWork 950.00 950.00 +0.00% BenchmarkSyscallWork-2 481.00 480.00 -0.21% BenchmarkSyscallWork-4 268.00 270.00 +0.75% BenchmarkSyscallWork-8 156.00 169.00 +8.33% BenchmarkSyscallWork-16 188.00 184.00 -2.13% BenchmarkSemaSyntNonblock 36.40 35.60 -2.20% BenchmarkSemaSyntNonblock-2 81.40 45.10 -44.59% BenchmarkSemaSyntNonblock-4 126.00 108.00 -14.29% BenchmarkSemaSyntNonblock-8 112.00 112.00 +0.00% BenchmarkSemaSyntNonblock-16 110.00 112.00 +1.82% BenchmarkSemaSyntBlock 35.30 35.30 +0.00% BenchmarkSemaSyntBlock-2 118.00 124.00 +5.08% BenchmarkSemaSyntBlock-4 105.00 108.00 +2.86% BenchmarkSemaSyntBlock-8 101.00 111.00 +9.90% BenchmarkSemaSyntBlock-16 112.00 118.00 +5.36% BenchmarkSemaWorkNonblock 810.00 811.00 +0.12% BenchmarkSemaWorkNonblock-2 476.00 414.00 -13.03% BenchmarkSemaWorkNonblock-4 238.00 228.00 -4.20% BenchmarkSemaWorkNonblock-8 140.00 126.00 -10.00% BenchmarkSemaWorkNonblock-16 117.00 116.00 -0.85% BenchmarkSemaWorkBlock 810.00 811.00 +0.12% BenchmarkSemaWorkBlock-2 454.00 466.00 +2.64% BenchmarkSemaWorkBlock-4 243.00 241.00 -0.82% BenchmarkSemaWorkBlock-8 145.00 137.00 -5.52% BenchmarkSemaWorkBlock-16 132.00 123.00 -6.82% BenchmarkContendedSemaphore 123.00 102.00 -17.07% BenchmarkContendedSemaphore-2 34.80 34.90 +0.29% BenchmarkContendedSemaphore-4 34.70 34.80 +0.29% BenchmarkContendedSemaphore-8 34.70 34.70 +0.00% BenchmarkContendedSemaphore-16 34.80 34.70 -0.29% BenchmarkMutex 26.80 26.00 -2.99% BenchmarkMutex-2 108.00 45.20 -58.15% BenchmarkMutex-4 103.00 127.00 +23.30% BenchmarkMutex-8 109.00 147.00 +34.86% BenchmarkMutex-16 102.00 152.00 +49.02% BenchmarkMutexSlack 27.00 26.90 -0.37% BenchmarkMutexSlack-2 149.00 165.00 +10.74% BenchmarkMutexSlack-4 121.00 209.00 +72.73% BenchmarkMutexSlack-8 101.00 158.00 +56.44% BenchmarkMutexSlack-16 97.00 129.00 +32.99% BenchmarkMutexWork 792.00 794.00 +0.25% BenchmarkMutexWork-2 407.00 409.00 +0.49% BenchmarkMutexWork-4 220.00 209.00 -5.00% BenchmarkMutexWork-8 267.00 160.00 -40.07% BenchmarkMutexWork-16 315.00 300.00 -4.76% BenchmarkMutexWorkSlack 792.00 793.00 +0.13% BenchmarkMutexWorkSlack-2 406.00 404.00 -0.49% BenchmarkMutexWorkSlack-4 225.00 212.00 -5.78% BenchmarkMutexWorkSlack-8 268.00 136.00 -49.25% BenchmarkMutexWorkSlack-16 300.00 300.00 +0.00% BenchmarkRWMutexWrite100 27.10 27.00 -0.37% BenchmarkRWMutexWrite100-2 33.10 40.80 +23.26% BenchmarkRWMutexWrite100-4 113.00 88.10 -22.04% BenchmarkRWMutexWrite100-8 119.00 95.30 -19.92% BenchmarkRWMutexWrite100-16 148.00 109.00 -26.35% BenchmarkRWMutexWrite10 29.60 29.40 -0.68% BenchmarkRWMutexWrite10-2 111.00 61.40 -44.68% BenchmarkRWMutexWrite10-4 270.00 208.00 -22.96% BenchmarkRWMutexWrite10-8 204.00 185.00 -9.31% BenchmarkRWMutexWrite10-16 261.00 190.00 -27.20% BenchmarkRWMutexWorkWrite100 1040.00 1036.00 -0.38% BenchmarkRWMutexWorkWrite100-2 593.00 580.00 -2.19% BenchmarkRWMutexWorkWrite100-4 470.00 365.00 -22.34% BenchmarkRWMutexWorkWrite100-8 468.00 289.00 -38.25% BenchmarkRWMutexWorkWrite100-16 604.00 374.00 -38.08% BenchmarkRWMutexWorkWrite10 951.00 951.00 +0.00% BenchmarkRWMutexWorkWrite10-2 1001.00 928.00 -7.29% BenchmarkRWMutexWorkWrite10-4 1555.00 1006.00 -35.31% BenchmarkRWMutexWorkWrite10-8 2085.00 1171.00 -43.84% BenchmarkRWMutexWorkWrite10-16 2082.00 1614.00 -22.48% R=rsc, iant, msolo, fw, iant CC=golang-dev https://golang.org/cl/4711045
2011-07-29 10:44:06 -06:00
again:
PAUSE
SUBL $1, AX
JNZ again
RET
TEXT runtime·atomicstorep1(SB), NOSPLIT, $0-16
cmd/cc, runtime: convert C compilers to use Go calling convention To date, the C compilers and Go compilers differed only in how values were returned from functions. This made it difficult to call Go from C or C from Go if return values were involved. It also made assembly called from Go and assembly called from C different. This CL changes the C compiler to use the Go conventions, passing results on the stack, after the arguments. [Exception: this does not apply to C ... functions, because you can't know where on the stack the arguments end.] By doing this, the CL makes it possible to rewrite C functions into Go one at a time, without worrying about which languages call that function or which languages it calls. This CL also updates all the assembly files in package runtime to use the new conventions. Argument references of the form 40(SP) have been rewritten to the form name+10(FP) instead, and there are now Go func prototypes for every assembly function called from C or Go. This means that 'go vet runtime' checks effectively every assembly function, and go vet's output was used to automate the bulk of the conversion. Some functions, like seek and nsec on Plan 9, needed to be rewritten. Many assembly routines called from C were reading arguments incorrectly, using MOVL instead of MOVQ or vice versa, especially on the less used systems like openbsd. These were found by go vet and have been corrected too. If we're lucky, this may reduce flakiness on those systems. Tested on: darwin/386 darwin/amd64 linux/arm linux/386 linux/amd64 If this breaks another system, the bug is almost certainly in the sys_$GOOS_$GOARCH.s file, since the rest of the CL is tested by the combination of the above systems. LGTM=dvyukov, iant R=golang-codereviews, 0intro, dave, alex.brainman, dvyukov, iant CC=golang-codereviews, josharian, r https://golang.org/cl/135830043
2014-08-27 09:32:17 -06:00
MOVQ ptr+0(FP), BX
MOVQ val+8(FP), AX
XCHGQ AX, 0(BX)
RET
TEXT runtime·atomicstore(SB), NOSPLIT, $0-12
cmd/cc, runtime: convert C compilers to use Go calling convention To date, the C compilers and Go compilers differed only in how values were returned from functions. This made it difficult to call Go from C or C from Go if return values were involved. It also made assembly called from Go and assembly called from C different. This CL changes the C compiler to use the Go conventions, passing results on the stack, after the arguments. [Exception: this does not apply to C ... functions, because you can't know where on the stack the arguments end.] By doing this, the CL makes it possible to rewrite C functions into Go one at a time, without worrying about which languages call that function or which languages it calls. This CL also updates all the assembly files in package runtime to use the new conventions. Argument references of the form 40(SP) have been rewritten to the form name+10(FP) instead, and there are now Go func prototypes for every assembly function called from C or Go. This means that 'go vet runtime' checks effectively every assembly function, and go vet's output was used to automate the bulk of the conversion. Some functions, like seek and nsec on Plan 9, needed to be rewritten. Many assembly routines called from C were reading arguments incorrectly, using MOVL instead of MOVQ or vice versa, especially on the less used systems like openbsd. These were found by go vet and have been corrected too. If we're lucky, this may reduce flakiness on those systems. Tested on: darwin/386 darwin/amd64 linux/arm linux/386 linux/amd64 If this breaks another system, the bug is almost certainly in the sys_$GOOS_$GOARCH.s file, since the rest of the CL is tested by the combination of the above systems. LGTM=dvyukov, iant R=golang-codereviews, 0intro, dave, alex.brainman, dvyukov, iant CC=golang-codereviews, josharian, r https://golang.org/cl/135830043
2014-08-27 09:32:17 -06:00
MOVQ ptr+0(FP), BX
MOVL val+8(FP), AX
XCHGL AX, 0(BX)
RET
TEXT runtime·atomicstore64(SB), NOSPLIT, $0-16
cmd/cc, runtime: convert C compilers to use Go calling convention To date, the C compilers and Go compilers differed only in how values were returned from functions. This made it difficult to call Go from C or C from Go if return values were involved. It also made assembly called from Go and assembly called from C different. This CL changes the C compiler to use the Go conventions, passing results on the stack, after the arguments. [Exception: this does not apply to C ... functions, because you can't know where on the stack the arguments end.] By doing this, the CL makes it possible to rewrite C functions into Go one at a time, without worrying about which languages call that function or which languages it calls. This CL also updates all the assembly files in package runtime to use the new conventions. Argument references of the form 40(SP) have been rewritten to the form name+10(FP) instead, and there are now Go func prototypes for every assembly function called from C or Go. This means that 'go vet runtime' checks effectively every assembly function, and go vet's output was used to automate the bulk of the conversion. Some functions, like seek and nsec on Plan 9, needed to be rewritten. Many assembly routines called from C were reading arguments incorrectly, using MOVL instead of MOVQ or vice versa, especially on the less used systems like openbsd. These were found by go vet and have been corrected too. If we're lucky, this may reduce flakiness on those systems. Tested on: darwin/386 darwin/amd64 linux/arm linux/386 linux/amd64 If this breaks another system, the bug is almost certainly in the sys_$GOOS_$GOARCH.s file, since the rest of the CL is tested by the combination of the above systems. LGTM=dvyukov, iant R=golang-codereviews, 0intro, dave, alex.brainman, dvyukov, iant CC=golang-codereviews, josharian, r https://golang.org/cl/135830043
2014-08-27 09:32:17 -06:00
MOVQ ptr+0(FP), BX
MOVQ val+8(FP), AX
XCHGQ AX, 0(BX)
RET
// void runtime·atomicor8(byte volatile*, byte);
cmd/cc, runtime: convert C compilers to use Go calling convention To date, the C compilers and Go compilers differed only in how values were returned from functions. This made it difficult to call Go from C or C from Go if return values were involved. It also made assembly called from Go and assembly called from C different. This CL changes the C compiler to use the Go conventions, passing results on the stack, after the arguments. [Exception: this does not apply to C ... functions, because you can't know where on the stack the arguments end.] By doing this, the CL makes it possible to rewrite C functions into Go one at a time, without worrying about which languages call that function or which languages it calls. This CL also updates all the assembly files in package runtime to use the new conventions. Argument references of the form 40(SP) have been rewritten to the form name+10(FP) instead, and there are now Go func prototypes for every assembly function called from C or Go. This means that 'go vet runtime' checks effectively every assembly function, and go vet's output was used to automate the bulk of the conversion. Some functions, like seek and nsec on Plan 9, needed to be rewritten. Many assembly routines called from C were reading arguments incorrectly, using MOVL instead of MOVQ or vice versa, especially on the less used systems like openbsd. These were found by go vet and have been corrected too. If we're lucky, this may reduce flakiness on those systems. Tested on: darwin/386 darwin/amd64 linux/arm linux/386 linux/amd64 If this breaks another system, the bug is almost certainly in the sys_$GOOS_$GOARCH.s file, since the rest of the CL is tested by the combination of the above systems. LGTM=dvyukov, iant R=golang-codereviews, 0intro, dave, alex.brainman, dvyukov, iant CC=golang-codereviews, josharian, r https://golang.org/cl/135830043
2014-08-27 09:32:17 -06:00
TEXT runtime·atomicor8(SB), NOSPLIT, $0-9
MOVQ ptr+0(FP), AX
MOVB val+8(FP), BX
LOCK
ORB BX, (AX)
RET
// void runtime·atomicand8(byte volatile*, byte);
TEXT runtime·atomicand8(SB), NOSPLIT, $0-9
MOVQ ptr+0(FP), AX
MOVB val+8(FP), BX
LOCK
ANDB BX, (AX)
RET
// void jmpdefer(fn, sp);
// called from deferreturn.
2009-01-27 13:03:53 -07:00
// 1. pop the caller
// 2. sub 5 bytes from the callers return
// 3. jmp to the argument
TEXT runtime·jmpdefer(SB), NOSPLIT, $0-16
cmd/cc, runtime: convert C compilers to use Go calling convention To date, the C compilers and Go compilers differed only in how values were returned from functions. This made it difficult to call Go from C or C from Go if return values were involved. It also made assembly called from Go and assembly called from C different. This CL changes the C compiler to use the Go conventions, passing results on the stack, after the arguments. [Exception: this does not apply to C ... functions, because you can't know where on the stack the arguments end.] By doing this, the CL makes it possible to rewrite C functions into Go one at a time, without worrying about which languages call that function or which languages it calls. This CL also updates all the assembly files in package runtime to use the new conventions. Argument references of the form 40(SP) have been rewritten to the form name+10(FP) instead, and there are now Go func prototypes for every assembly function called from C or Go. This means that 'go vet runtime' checks effectively every assembly function, and go vet's output was used to automate the bulk of the conversion. Some functions, like seek and nsec on Plan 9, needed to be rewritten. Many assembly routines called from C were reading arguments incorrectly, using MOVL instead of MOVQ or vice versa, especially on the less used systems like openbsd. These were found by go vet and have been corrected too. If we're lucky, this may reduce flakiness on those systems. Tested on: darwin/386 darwin/amd64 linux/arm linux/386 linux/amd64 If this breaks another system, the bug is almost certainly in the sys_$GOOS_$GOARCH.s file, since the rest of the CL is tested by the combination of the above systems. LGTM=dvyukov, iant R=golang-codereviews, 0intro, dave, alex.brainman, dvyukov, iant CC=golang-codereviews, josharian, r https://golang.org/cl/135830043
2014-08-27 09:32:17 -06:00
MOVQ fv+0(FP), DX // fn
MOVQ argp+8(FP), BX // caller sp
LEAQ -8(BX), SP // caller sp after CALL
SUBQ $5, (SP) // return to CALL again
MOVQ 0(DX), BX
JMP BX // but first run the deferred function
// Save state of caller into g->sched. Smashes R8, R9.
TEXT gosave<>(SB),NOSPLIT,$0
get_tls(R8)
MOVQ g(R8), R8
MOVQ 0(SP), R9
MOVQ R9, (g_sched+gobuf_pc)(R8)
LEAQ 8(SP), R9
MOVQ R9, (g_sched+gobuf_sp)(R8)
MOVQ $0, (g_sched+gobuf_ret)(R8)
MOVQ $0, (g_sched+gobuf_ctxt)(R8)
MOVQ BP, (g_sched+gobuf_bp)(R8)
runtime: scheduler, cgo reorganization * Change use of m->g0 stack (aka scheduler stack). * Provide runtime.mcall(f) to invoke f() on m->g0 stack. * Replace scheduler loop entry with runtime.mcall(schedule). Runtime.mcall eliminates the need for fake scheduler states that exist just to run a bit of code on the m->g0 stack (Grecovery, Gstackalloc). The elimination of the scheduler as a loop that stops and starts using gosave and gogo fixes a bad interaction with the way cgo uses the m->g0 stack. Cgo runs external (gcc-compiled) C functions on that stack, and then when calling back into Go, it sets m->g0->sched.sp below the added call frames, so that other uses of m->g0's stack will not interfere with those frames. Unfortunately, gogo (longjmp) back to the scheduler loop at this point would end up running scheduler with the lower sp, which no longer points at a valid stack frame for a call to scheduler. If scheduler then wrote any function call arguments or local variables to where it expected the stack frame to be, it would overwrite other data on the stack. I realized this possibility while debugging a problem with calling complex Go code in a Go -> C -> Go cgo callback. This wasn't the bug I was looking for, it turns out, but I believe it is a real bug nonetheless. Switching to runtime.mcall, which only adds new frames to the stack and never jumps into functions running in existing ones, fixes this bug. * Move cgo-related code out of proc.c into cgocall.c. * Add very large comment describing cgo call sequences. * Simpilify, regularize cgo function implementations and names. * Add test suite as misc/cgo/test. Now the Go -> C path calls cgocall, which calls asmcgocall, and the C -> Go path calls cgocallback, which calls cgocallbackg. The shuffling, which affects mainly the callback case, moves most of the callback implementation to cgocallback running on the m->curg stack (not the m->g0 scheduler stack) and only while accounted for with $GOMAXPROCS (between calls to exitsyscall and entersyscall). The previous callback code did not block in startcgocallback's approximation to exitsyscall, so if, say, the garbage collector were running, it would still barge in and start doing things like call malloc. Similarly endcgocallback's approximation of entersyscall did not call matchmg to kick off new OS threads when necessary, which caused the bug in issue 1560. Fixes #1560. R=iant CC=golang-dev https://golang.org/cl/4253054
2011-03-07 08:37:42 -07:00
RET
// func asmcgocall(fn, arg unsafe.Pointer) int32
// Call fn(arg) on the scheduler stack,
// aligned appropriately for the gcc ABI.
// See cgocall.go for more details.
TEXT ·asmcgocall(SB),NOSPLIT,$0-20
runtime: scheduler, cgo reorganization * Change use of m->g0 stack (aka scheduler stack). * Provide runtime.mcall(f) to invoke f() on m->g0 stack. * Replace scheduler loop entry with runtime.mcall(schedule). Runtime.mcall eliminates the need for fake scheduler states that exist just to run a bit of code on the m->g0 stack (Grecovery, Gstackalloc). The elimination of the scheduler as a loop that stops and starts using gosave and gogo fixes a bad interaction with the way cgo uses the m->g0 stack. Cgo runs external (gcc-compiled) C functions on that stack, and then when calling back into Go, it sets m->g0->sched.sp below the added call frames, so that other uses of m->g0's stack will not interfere with those frames. Unfortunately, gogo (longjmp) back to the scheduler loop at this point would end up running scheduler with the lower sp, which no longer points at a valid stack frame for a call to scheduler. If scheduler then wrote any function call arguments or local variables to where it expected the stack frame to be, it would overwrite other data on the stack. I realized this possibility while debugging a problem with calling complex Go code in a Go -> C -> Go cgo callback. This wasn't the bug I was looking for, it turns out, but I believe it is a real bug nonetheless. Switching to runtime.mcall, which only adds new frames to the stack and never jumps into functions running in existing ones, fixes this bug. * Move cgo-related code out of proc.c into cgocall.c. * Add very large comment describing cgo call sequences. * Simpilify, regularize cgo function implementations and names. * Add test suite as misc/cgo/test. Now the Go -> C path calls cgocall, which calls asmcgocall, and the C -> Go path calls cgocallback, which calls cgocallbackg. The shuffling, which affects mainly the callback case, moves most of the callback implementation to cgocallback running on the m->curg stack (not the m->g0 scheduler stack) and only while accounted for with $GOMAXPROCS (between calls to exitsyscall and entersyscall). The previous callback code did not block in startcgocallback's approximation to exitsyscall, so if, say, the garbage collector were running, it would still barge in and start doing things like call malloc. Similarly endcgocallback's approximation of entersyscall did not call matchmg to kick off new OS threads when necessary, which caused the bug in issue 1560. Fixes #1560. R=iant CC=golang-dev https://golang.org/cl/4253054
2011-03-07 08:37:42 -07:00
MOVQ fn+0(FP), AX
MOVQ arg+8(FP), BX
runtime: scheduler, cgo reorganization * Change use of m->g0 stack (aka scheduler stack). * Provide runtime.mcall(f) to invoke f() on m->g0 stack. * Replace scheduler loop entry with runtime.mcall(schedule). Runtime.mcall eliminates the need for fake scheduler states that exist just to run a bit of code on the m->g0 stack (Grecovery, Gstackalloc). The elimination of the scheduler as a loop that stops and starts using gosave and gogo fixes a bad interaction with the way cgo uses the m->g0 stack. Cgo runs external (gcc-compiled) C functions on that stack, and then when calling back into Go, it sets m->g0->sched.sp below the added call frames, so that other uses of m->g0's stack will not interfere with those frames. Unfortunately, gogo (longjmp) back to the scheduler loop at this point would end up running scheduler with the lower sp, which no longer points at a valid stack frame for a call to scheduler. If scheduler then wrote any function call arguments or local variables to where it expected the stack frame to be, it would overwrite other data on the stack. I realized this possibility while debugging a problem with calling complex Go code in a Go -> C -> Go cgo callback. This wasn't the bug I was looking for, it turns out, but I believe it is a real bug nonetheless. Switching to runtime.mcall, which only adds new frames to the stack and never jumps into functions running in existing ones, fixes this bug. * Move cgo-related code out of proc.c into cgocall.c. * Add very large comment describing cgo call sequences. * Simpilify, regularize cgo function implementations and names. * Add test suite as misc/cgo/test. Now the Go -> C path calls cgocall, which calls asmcgocall, and the C -> Go path calls cgocallback, which calls cgocallbackg. The shuffling, which affects mainly the callback case, moves most of the callback implementation to cgocallback running on the m->curg stack (not the m->g0 scheduler stack) and only while accounted for with $GOMAXPROCS (between calls to exitsyscall and entersyscall). The previous callback code did not block in startcgocallback's approximation to exitsyscall, so if, say, the garbage collector were running, it would still barge in and start doing things like call malloc. Similarly endcgocallback's approximation of entersyscall did not call matchmg to kick off new OS threads when necessary, which caused the bug in issue 1560. Fixes #1560. R=iant CC=golang-dev https://golang.org/cl/4253054
2011-03-07 08:37:42 -07:00
MOVQ SP, DX
// Figure out if we need to switch to m->g0 stack.
runtime: scheduler, cgo reorganization * Change use of m->g0 stack (aka scheduler stack). * Provide runtime.mcall(f) to invoke f() on m->g0 stack. * Replace scheduler loop entry with runtime.mcall(schedule). Runtime.mcall eliminates the need for fake scheduler states that exist just to run a bit of code on the m->g0 stack (Grecovery, Gstackalloc). The elimination of the scheduler as a loop that stops and starts using gosave and gogo fixes a bad interaction with the way cgo uses the m->g0 stack. Cgo runs external (gcc-compiled) C functions on that stack, and then when calling back into Go, it sets m->g0->sched.sp below the added call frames, so that other uses of m->g0's stack will not interfere with those frames. Unfortunately, gogo (longjmp) back to the scheduler loop at this point would end up running scheduler with the lower sp, which no longer points at a valid stack frame for a call to scheduler. If scheduler then wrote any function call arguments or local variables to where it expected the stack frame to be, it would overwrite other data on the stack. I realized this possibility while debugging a problem with calling complex Go code in a Go -> C -> Go cgo callback. This wasn't the bug I was looking for, it turns out, but I believe it is a real bug nonetheless. Switching to runtime.mcall, which only adds new frames to the stack and never jumps into functions running in existing ones, fixes this bug. * Move cgo-related code out of proc.c into cgocall.c. * Add very large comment describing cgo call sequences. * Simpilify, regularize cgo function implementations and names. * Add test suite as misc/cgo/test. Now the Go -> C path calls cgocall, which calls asmcgocall, and the C -> Go path calls cgocallback, which calls cgocallbackg. The shuffling, which affects mainly the callback case, moves most of the callback implementation to cgocallback running on the m->curg stack (not the m->g0 scheduler stack) and only while accounted for with $GOMAXPROCS (between calls to exitsyscall and entersyscall). The previous callback code did not block in startcgocallback's approximation to exitsyscall, so if, say, the garbage collector were running, it would still barge in and start doing things like call malloc. Similarly endcgocallback's approximation of entersyscall did not call matchmg to kick off new OS threads when necessary, which caused the bug in issue 1560. Fixes #1560. R=iant CC=golang-dev https://golang.org/cl/4253054
2011-03-07 08:37:42 -07:00
// We get called to create new OS threads too, and those
// come in on the m->g0 stack already.
get_tls(CX)
MOVQ g(CX), R8
MOVQ g_m(R8), R8
MOVQ m_g0(R8), SI
runtime: scheduler, cgo reorganization * Change use of m->g0 stack (aka scheduler stack). * Provide runtime.mcall(f) to invoke f() on m->g0 stack. * Replace scheduler loop entry with runtime.mcall(schedule). Runtime.mcall eliminates the need for fake scheduler states that exist just to run a bit of code on the m->g0 stack (Grecovery, Gstackalloc). The elimination of the scheduler as a loop that stops and starts using gosave and gogo fixes a bad interaction with the way cgo uses the m->g0 stack. Cgo runs external (gcc-compiled) C functions on that stack, and then when calling back into Go, it sets m->g0->sched.sp below the added call frames, so that other uses of m->g0's stack will not interfere with those frames. Unfortunately, gogo (longjmp) back to the scheduler loop at this point would end up running scheduler with the lower sp, which no longer points at a valid stack frame for a call to scheduler. If scheduler then wrote any function call arguments or local variables to where it expected the stack frame to be, it would overwrite other data on the stack. I realized this possibility while debugging a problem with calling complex Go code in a Go -> C -> Go cgo callback. This wasn't the bug I was looking for, it turns out, but I believe it is a real bug nonetheless. Switching to runtime.mcall, which only adds new frames to the stack and never jumps into functions running in existing ones, fixes this bug. * Move cgo-related code out of proc.c into cgocall.c. * Add very large comment describing cgo call sequences. * Simpilify, regularize cgo function implementations and names. * Add test suite as misc/cgo/test. Now the Go -> C path calls cgocall, which calls asmcgocall, and the C -> Go path calls cgocallback, which calls cgocallbackg. The shuffling, which affects mainly the callback case, moves most of the callback implementation to cgocallback running on the m->curg stack (not the m->g0 scheduler stack) and only while accounted for with $GOMAXPROCS (between calls to exitsyscall and entersyscall). The previous callback code did not block in startcgocallback's approximation to exitsyscall, so if, say, the garbage collector were running, it would still barge in and start doing things like call malloc. Similarly endcgocallback's approximation of entersyscall did not call matchmg to kick off new OS threads when necessary, which caused the bug in issue 1560. Fixes #1560. R=iant CC=golang-dev https://golang.org/cl/4253054
2011-03-07 08:37:42 -07:00
MOVQ g(CX), DI
CMPQ SI, DI
JEQ nosave
MOVQ m_gsignal(R8), SI
CMPQ SI, DI
JEQ nosave
MOVQ m_g0(R8), SI
CALL gosave<>(SB)
runtime: scheduler, cgo reorganization * Change use of m->g0 stack (aka scheduler stack). * Provide runtime.mcall(f) to invoke f() on m->g0 stack. * Replace scheduler loop entry with runtime.mcall(schedule). Runtime.mcall eliminates the need for fake scheduler states that exist just to run a bit of code on the m->g0 stack (Grecovery, Gstackalloc). The elimination of the scheduler as a loop that stops and starts using gosave and gogo fixes a bad interaction with the way cgo uses the m->g0 stack. Cgo runs external (gcc-compiled) C functions on that stack, and then when calling back into Go, it sets m->g0->sched.sp below the added call frames, so that other uses of m->g0's stack will not interfere with those frames. Unfortunately, gogo (longjmp) back to the scheduler loop at this point would end up running scheduler with the lower sp, which no longer points at a valid stack frame for a call to scheduler. If scheduler then wrote any function call arguments or local variables to where it expected the stack frame to be, it would overwrite other data on the stack. I realized this possibility while debugging a problem with calling complex Go code in a Go -> C -> Go cgo callback. This wasn't the bug I was looking for, it turns out, but I believe it is a real bug nonetheless. Switching to runtime.mcall, which only adds new frames to the stack and never jumps into functions running in existing ones, fixes this bug. * Move cgo-related code out of proc.c into cgocall.c. * Add very large comment describing cgo call sequences. * Simpilify, regularize cgo function implementations and names. * Add test suite as misc/cgo/test. Now the Go -> C path calls cgocall, which calls asmcgocall, and the C -> Go path calls cgocallback, which calls cgocallbackg. The shuffling, which affects mainly the callback case, moves most of the callback implementation to cgocallback running on the m->curg stack (not the m->g0 scheduler stack) and only while accounted for with $GOMAXPROCS (between calls to exitsyscall and entersyscall). The previous callback code did not block in startcgocallback's approximation to exitsyscall, so if, say, the garbage collector were running, it would still barge in and start doing things like call malloc. Similarly endcgocallback's approximation of entersyscall did not call matchmg to kick off new OS threads when necessary, which caused the bug in issue 1560. Fixes #1560. R=iant CC=golang-dev https://golang.org/cl/4253054
2011-03-07 08:37:42 -07:00
MOVQ SI, g(CX)
MOVQ (g_sched+gobuf_sp)(SI), SP
nosave:
// Now on a scheduling stack (a pthread-created stack).
// Make sure we have enough room for 4 stack-backed fast-call
// registers as per windows amd64 calling convention.
SUBQ $64, SP
ANDQ $~15, SP // alignment for gcc ABI
MOVQ DI, 48(SP) // save g
MOVQ (g_stack+stack_hi)(DI), DI
SUBQ DX, DI
MOVQ DI, 40(SP) // save depth in stack (can't just save SP, as stack might be copied during a callback)
runtime: scheduler, cgo reorganization * Change use of m->g0 stack (aka scheduler stack). * Provide runtime.mcall(f) to invoke f() on m->g0 stack. * Replace scheduler loop entry with runtime.mcall(schedule). Runtime.mcall eliminates the need for fake scheduler states that exist just to run a bit of code on the m->g0 stack (Grecovery, Gstackalloc). The elimination of the scheduler as a loop that stops and starts using gosave and gogo fixes a bad interaction with the way cgo uses the m->g0 stack. Cgo runs external (gcc-compiled) C functions on that stack, and then when calling back into Go, it sets m->g0->sched.sp below the added call frames, so that other uses of m->g0's stack will not interfere with those frames. Unfortunately, gogo (longjmp) back to the scheduler loop at this point would end up running scheduler with the lower sp, which no longer points at a valid stack frame for a call to scheduler. If scheduler then wrote any function call arguments or local variables to where it expected the stack frame to be, it would overwrite other data on the stack. I realized this possibility while debugging a problem with calling complex Go code in a Go -> C -> Go cgo callback. This wasn't the bug I was looking for, it turns out, but I believe it is a real bug nonetheless. Switching to runtime.mcall, which only adds new frames to the stack and never jumps into functions running in existing ones, fixes this bug. * Move cgo-related code out of proc.c into cgocall.c. * Add very large comment describing cgo call sequences. * Simpilify, regularize cgo function implementations and names. * Add test suite as misc/cgo/test. Now the Go -> C path calls cgocall, which calls asmcgocall, and the C -> Go path calls cgocallback, which calls cgocallbackg. The shuffling, which affects mainly the callback case, moves most of the callback implementation to cgocallback running on the m->curg stack (not the m->g0 scheduler stack) and only while accounted for with $GOMAXPROCS (between calls to exitsyscall and entersyscall). The previous callback code did not block in startcgocallback's approximation to exitsyscall, so if, say, the garbage collector were running, it would still barge in and start doing things like call malloc. Similarly endcgocallback's approximation of entersyscall did not call matchmg to kick off new OS threads when necessary, which caused the bug in issue 1560. Fixes #1560. R=iant CC=golang-dev https://golang.org/cl/4253054
2011-03-07 08:37:42 -07:00
MOVQ BX, DI // DI = first argument in AMD64 ABI
MOVQ BX, CX // CX = first argument in Win64
runtime: scheduler, cgo reorganization * Change use of m->g0 stack (aka scheduler stack). * Provide runtime.mcall(f) to invoke f() on m->g0 stack. * Replace scheduler loop entry with runtime.mcall(schedule). Runtime.mcall eliminates the need for fake scheduler states that exist just to run a bit of code on the m->g0 stack (Grecovery, Gstackalloc). The elimination of the scheduler as a loop that stops and starts using gosave and gogo fixes a bad interaction with the way cgo uses the m->g0 stack. Cgo runs external (gcc-compiled) C functions on that stack, and then when calling back into Go, it sets m->g0->sched.sp below the added call frames, so that other uses of m->g0's stack will not interfere with those frames. Unfortunately, gogo (longjmp) back to the scheduler loop at this point would end up running scheduler with the lower sp, which no longer points at a valid stack frame for a call to scheduler. If scheduler then wrote any function call arguments or local variables to where it expected the stack frame to be, it would overwrite other data on the stack. I realized this possibility while debugging a problem with calling complex Go code in a Go -> C -> Go cgo callback. This wasn't the bug I was looking for, it turns out, but I believe it is a real bug nonetheless. Switching to runtime.mcall, which only adds new frames to the stack and never jumps into functions running in existing ones, fixes this bug. * Move cgo-related code out of proc.c into cgocall.c. * Add very large comment describing cgo call sequences. * Simpilify, regularize cgo function implementations and names. * Add test suite as misc/cgo/test. Now the Go -> C path calls cgocall, which calls asmcgocall, and the C -> Go path calls cgocallback, which calls cgocallbackg. The shuffling, which affects mainly the callback case, moves most of the callback implementation to cgocallback running on the m->curg stack (not the m->g0 scheduler stack) and only while accounted for with $GOMAXPROCS (between calls to exitsyscall and entersyscall). The previous callback code did not block in startcgocallback's approximation to exitsyscall, so if, say, the garbage collector were running, it would still barge in and start doing things like call malloc. Similarly endcgocallback's approximation of entersyscall did not call matchmg to kick off new OS threads when necessary, which caused the bug in issue 1560. Fixes #1560. R=iant CC=golang-dev https://golang.org/cl/4253054
2011-03-07 08:37:42 -07:00
CALL AX
// Restore registers, g, stack pointer.
runtime: scheduler, cgo reorganization * Change use of m->g0 stack (aka scheduler stack). * Provide runtime.mcall(f) to invoke f() on m->g0 stack. * Replace scheduler loop entry with runtime.mcall(schedule). Runtime.mcall eliminates the need for fake scheduler states that exist just to run a bit of code on the m->g0 stack (Grecovery, Gstackalloc). The elimination of the scheduler as a loop that stops and starts using gosave and gogo fixes a bad interaction with the way cgo uses the m->g0 stack. Cgo runs external (gcc-compiled) C functions on that stack, and then when calling back into Go, it sets m->g0->sched.sp below the added call frames, so that other uses of m->g0's stack will not interfere with those frames. Unfortunately, gogo (longjmp) back to the scheduler loop at this point would end up running scheduler with the lower sp, which no longer points at a valid stack frame for a call to scheduler. If scheduler then wrote any function call arguments or local variables to where it expected the stack frame to be, it would overwrite other data on the stack. I realized this possibility while debugging a problem with calling complex Go code in a Go -> C -> Go cgo callback. This wasn't the bug I was looking for, it turns out, but I believe it is a real bug nonetheless. Switching to runtime.mcall, which only adds new frames to the stack and never jumps into functions running in existing ones, fixes this bug. * Move cgo-related code out of proc.c into cgocall.c. * Add very large comment describing cgo call sequences. * Simpilify, regularize cgo function implementations and names. * Add test suite as misc/cgo/test. Now the Go -> C path calls cgocall, which calls asmcgocall, and the C -> Go path calls cgocallback, which calls cgocallbackg. The shuffling, which affects mainly the callback case, moves most of the callback implementation to cgocallback running on the m->curg stack (not the m->g0 scheduler stack) and only while accounted for with $GOMAXPROCS (between calls to exitsyscall and entersyscall). The previous callback code did not block in startcgocallback's approximation to exitsyscall, so if, say, the garbage collector were running, it would still barge in and start doing things like call malloc. Similarly endcgocallback's approximation of entersyscall did not call matchmg to kick off new OS threads when necessary, which caused the bug in issue 1560. Fixes #1560. R=iant CC=golang-dev https://golang.org/cl/4253054
2011-03-07 08:37:42 -07:00
get_tls(CX)
MOVQ 48(SP), DI
MOVQ (g_stack+stack_hi)(DI), SI
SUBQ 40(SP), SI
runtime: scheduler, cgo reorganization * Change use of m->g0 stack (aka scheduler stack). * Provide runtime.mcall(f) to invoke f() on m->g0 stack. * Replace scheduler loop entry with runtime.mcall(schedule). Runtime.mcall eliminates the need for fake scheduler states that exist just to run a bit of code on the m->g0 stack (Grecovery, Gstackalloc). The elimination of the scheduler as a loop that stops and starts using gosave and gogo fixes a bad interaction with the way cgo uses the m->g0 stack. Cgo runs external (gcc-compiled) C functions on that stack, and then when calling back into Go, it sets m->g0->sched.sp below the added call frames, so that other uses of m->g0's stack will not interfere with those frames. Unfortunately, gogo (longjmp) back to the scheduler loop at this point would end up running scheduler with the lower sp, which no longer points at a valid stack frame for a call to scheduler. If scheduler then wrote any function call arguments or local variables to where it expected the stack frame to be, it would overwrite other data on the stack. I realized this possibility while debugging a problem with calling complex Go code in a Go -> C -> Go cgo callback. This wasn't the bug I was looking for, it turns out, but I believe it is a real bug nonetheless. Switching to runtime.mcall, which only adds new frames to the stack and never jumps into functions running in existing ones, fixes this bug. * Move cgo-related code out of proc.c into cgocall.c. * Add very large comment describing cgo call sequences. * Simpilify, regularize cgo function implementations and names. * Add test suite as misc/cgo/test. Now the Go -> C path calls cgocall, which calls asmcgocall, and the C -> Go path calls cgocallback, which calls cgocallbackg. The shuffling, which affects mainly the callback case, moves most of the callback implementation to cgocallback running on the m->curg stack (not the m->g0 scheduler stack) and only while accounted for with $GOMAXPROCS (between calls to exitsyscall and entersyscall). The previous callback code did not block in startcgocallback's approximation to exitsyscall, so if, say, the garbage collector were running, it would still barge in and start doing things like call malloc. Similarly endcgocallback's approximation of entersyscall did not call matchmg to kick off new OS threads when necessary, which caused the bug in issue 1560. Fixes #1560. R=iant CC=golang-dev https://golang.org/cl/4253054
2011-03-07 08:37:42 -07:00
MOVQ DI, g(CX)
MOVQ SI, SP
MOVL AX, ret+16(FP)
RET
runtime: scheduler, cgo reorganization * Change use of m->g0 stack (aka scheduler stack). * Provide runtime.mcall(f) to invoke f() on m->g0 stack. * Replace scheduler loop entry with runtime.mcall(schedule). Runtime.mcall eliminates the need for fake scheduler states that exist just to run a bit of code on the m->g0 stack (Grecovery, Gstackalloc). The elimination of the scheduler as a loop that stops and starts using gosave and gogo fixes a bad interaction with the way cgo uses the m->g0 stack. Cgo runs external (gcc-compiled) C functions on that stack, and then when calling back into Go, it sets m->g0->sched.sp below the added call frames, so that other uses of m->g0's stack will not interfere with those frames. Unfortunately, gogo (longjmp) back to the scheduler loop at this point would end up running scheduler with the lower sp, which no longer points at a valid stack frame for a call to scheduler. If scheduler then wrote any function call arguments or local variables to where it expected the stack frame to be, it would overwrite other data on the stack. I realized this possibility while debugging a problem with calling complex Go code in a Go -> C -> Go cgo callback. This wasn't the bug I was looking for, it turns out, but I believe it is a real bug nonetheless. Switching to runtime.mcall, which only adds new frames to the stack and never jumps into functions running in existing ones, fixes this bug. * Move cgo-related code out of proc.c into cgocall.c. * Add very large comment describing cgo call sequences. * Simpilify, regularize cgo function implementations and names. * Add test suite as misc/cgo/test. Now the Go -> C path calls cgocall, which calls asmcgocall, and the C -> Go path calls cgocallback, which calls cgocallbackg. The shuffling, which affects mainly the callback case, moves most of the callback implementation to cgocallback running on the m->curg stack (not the m->g0 scheduler stack) and only while accounted for with $GOMAXPROCS (between calls to exitsyscall and entersyscall). The previous callback code did not block in startcgocallback's approximation to exitsyscall, so if, say, the garbage collector were running, it would still barge in and start doing things like call malloc. Similarly endcgocallback's approximation of entersyscall did not call matchmg to kick off new OS threads when necessary, which caused the bug in issue 1560. Fixes #1560. R=iant CC=golang-dev https://golang.org/cl/4253054
2011-03-07 08:37:42 -07:00
// cgocallback(void (*fn)(void*), void *frame, uintptr framesize)
// Turn the fn into a Go func (by taking its address) and call
// cgocallback_gofunc.
TEXT runtime·cgocallback(SB),NOSPLIT,$24-24
LEAQ fn+0(FP), AX
MOVQ AX, 0(SP)
MOVQ frame+8(FP), AX
MOVQ AX, 8(SP)
MOVQ framesize+16(FP), AX
MOVQ AX, 16(SP)
MOVQ $runtime·cgocallback_gofunc(SB), AX
CALL AX
RET
// cgocallback_gofunc(FuncVal*, void *frame, uintptr framesize)
// See cgocall.go for more details.
TEXT ·cgocallback_gofunc(SB),NOSPLIT,$8-24
NO_LOCAL_POINTERS
2014-06-26 09:54:39 -06:00
// If g is nil, Go did not create the current thread.
// Call needm to obtain one m for temporary use.
// In this case, we're running on the thread stack, so there's
// lots of space, but the linker doesn't know. Hide the call from
// the linker analysis by using an indirect call through AX.
get_tls(CX)
#ifdef GOOS_windows
MOVL $0, BX
CMPQ CX, $0
JEQ 2(PC)
#endif
MOVQ g(CX), BX
CMPQ BX, $0
2014-06-26 09:54:39 -06:00
JEQ needm
MOVQ g_m(BX), BX
MOVQ BX, R8 // holds oldm until end of function
2014-06-26 09:54:39 -06:00
JMP havem
needm:
2014-06-26 09:54:39 -06:00
MOVQ $0, 0(SP)
MOVQ $runtime·needm(SB), AX
CALL AX
MOVQ 0(SP), R8
get_tls(CX)
MOVQ g(CX), BX
MOVQ g_m(BX), BX
// Set m->sched.sp = SP, so that if a panic happens
// during the function we are about to execute, it will
// have a valid SP to run on the g0 stack.
// The next few lines (after the havem label)
// will save this SP onto the stack and then write
// the same SP back to m->sched.sp. That seems redundant,
// but if an unrecovered panic happens, unwindm will
// restore the g->sched.sp from the stack location
[dev.cc] runtime: delete scalararg, ptrarg; rename onM to systemstack Scalararg and ptrarg are not "signal safe". Go code filling them out can be interrupted by a signal, and then the signal handler runs, and if it also ends up in Go code that uses scalararg or ptrarg, now the old values have been smashed. For the pieces of code that do need to run in a signal handler, we introduced onM_signalok, which is really just onM except that the _signalok is meant to convey that the caller asserts that scalarg and ptrarg will be restored to their old values after the call (instead of the usual behavior, zeroing them). Scalararg and ptrarg are also untyped and therefore error-prone. Go code can always pass a closure instead of using scalararg and ptrarg; they were only really necessary for C code. And there's no more C code. For all these reasons, delete scalararg and ptrarg, converting the few remaining references to use closures. Once those are gone, there is no need for a distinction between onM and onM_signalok, so replace both with a single function equivalent to the current onM_signalok (that is, it can be called on any of the curg, g0, and gsignal stacks). The name onM and the phrase 'm stack' are misnomers, because on most system an M has two system stacks: the main thread stack and the signal handling stack. Correct the misnomer by naming the replacement function systemstack. Fix a few references to "M stack" in code. The main motivation for this change is to eliminate scalararg/ptrarg. Rick and I have already seen them cause problems because the calling sequence m.ptrarg[0] = p is a heap pointer assignment, so it gets a write barrier. The write barrier also uses onM, so it has all the same problems as if it were being invoked by a signal handler. We worked around this by saving and restoring the old values and by calling onM_signalok, but there's no point in keeping this nice home for bugs around any longer. This CL also changes funcline to return the file name as a result instead of filling in a passed-in *string. (The *string signature is left over from when the code was written in and called from C.) That's arguably an unrelated change, except that once I had done the ptrarg/scalararg/onM cleanup I started getting false positives about the *string argument escaping (not allowed in package runtime). The compiler is wrong, but the easiest fix is to write the code like Go code instead of like C code. I am a bit worried that the compiler is wrong because of some use of uninitialized memory in the escape analysis. If that's the reason, it will go away when we convert the compiler to Go. (And if not, we'll debug it the next time.) LGTM=khr R=r, khr CC=austin, golang-codereviews, iant, rlh https://golang.org/cl/174950043
2014-11-12 12:54:31 -07:00
// and then systemstack will try to use it. If we don't set it here,
// that restored SP will be uninitialized (typically 0) and
// will not be usable.
MOVQ m_g0(BX), SI
MOVQ SP, (g_sched+gobuf_sp)(SI)
havem:
// Now there's a valid m, and we're running on its m->g0.
// Save current m->g0->sched.sp on stack and then set it to SP.
// Save current sp in m->g0->sched.sp in preparation for
// switch back to m->curg stack.
// NOTE: unwindm knows that the saved g->sched.sp is at 0(SP).
MOVQ m_g0(BX), SI
MOVQ (g_sched+gobuf_sp)(SI), AX
MOVQ AX, 0(SP)
runtime: scheduler, cgo reorganization * Change use of m->g0 stack (aka scheduler stack). * Provide runtime.mcall(f) to invoke f() on m->g0 stack. * Replace scheduler loop entry with runtime.mcall(schedule). Runtime.mcall eliminates the need for fake scheduler states that exist just to run a bit of code on the m->g0 stack (Grecovery, Gstackalloc). The elimination of the scheduler as a loop that stops and starts using gosave and gogo fixes a bad interaction with the way cgo uses the m->g0 stack. Cgo runs external (gcc-compiled) C functions on that stack, and then when calling back into Go, it sets m->g0->sched.sp below the added call frames, so that other uses of m->g0's stack will not interfere with those frames. Unfortunately, gogo (longjmp) back to the scheduler loop at this point would end up running scheduler with the lower sp, which no longer points at a valid stack frame for a call to scheduler. If scheduler then wrote any function call arguments or local variables to where it expected the stack frame to be, it would overwrite other data on the stack. I realized this possibility while debugging a problem with calling complex Go code in a Go -> C -> Go cgo callback. This wasn't the bug I was looking for, it turns out, but I believe it is a real bug nonetheless. Switching to runtime.mcall, which only adds new frames to the stack and never jumps into functions running in existing ones, fixes this bug. * Move cgo-related code out of proc.c into cgocall.c. * Add very large comment describing cgo call sequences. * Simpilify, regularize cgo function implementations and names. * Add test suite as misc/cgo/test. Now the Go -> C path calls cgocall, which calls asmcgocall, and the C -> Go path calls cgocallback, which calls cgocallbackg. The shuffling, which affects mainly the callback case, moves most of the callback implementation to cgocallback running on the m->curg stack (not the m->g0 scheduler stack) and only while accounted for with $GOMAXPROCS (between calls to exitsyscall and entersyscall). The previous callback code did not block in startcgocallback's approximation to exitsyscall, so if, say, the garbage collector were running, it would still barge in and start doing things like call malloc. Similarly endcgocallback's approximation of entersyscall did not call matchmg to kick off new OS threads when necessary, which caused the bug in issue 1560. Fixes #1560. R=iant CC=golang-dev https://golang.org/cl/4253054
2011-03-07 08:37:42 -07:00
MOVQ SP, (g_sched+gobuf_sp)(SI)
// Switch to m->curg stack and call runtime.cgocallbackg.
// Because we are taking over the execution of m->curg
// but *not* resuming what had been running, we need to
// save that information (m->curg->sched) so we can restore it.
// We can restore m->curg->sched.sp easily, because calling
// runtime.cgocallbackg leaves SP unchanged upon return.
// To save m->curg->sched.pc, we push it onto the stack.
runtime: scheduler, cgo reorganization * Change use of m->g0 stack (aka scheduler stack). * Provide runtime.mcall(f) to invoke f() on m->g0 stack. * Replace scheduler loop entry with runtime.mcall(schedule). Runtime.mcall eliminates the need for fake scheduler states that exist just to run a bit of code on the m->g0 stack (Grecovery, Gstackalloc). The elimination of the scheduler as a loop that stops and starts using gosave and gogo fixes a bad interaction with the way cgo uses the m->g0 stack. Cgo runs external (gcc-compiled) C functions on that stack, and then when calling back into Go, it sets m->g0->sched.sp below the added call frames, so that other uses of m->g0's stack will not interfere with those frames. Unfortunately, gogo (longjmp) back to the scheduler loop at this point would end up running scheduler with the lower sp, which no longer points at a valid stack frame for a call to scheduler. If scheduler then wrote any function call arguments or local variables to where it expected the stack frame to be, it would overwrite other data on the stack. I realized this possibility while debugging a problem with calling complex Go code in a Go -> C -> Go cgo callback. This wasn't the bug I was looking for, it turns out, but I believe it is a real bug nonetheless. Switching to runtime.mcall, which only adds new frames to the stack and never jumps into functions running in existing ones, fixes this bug. * Move cgo-related code out of proc.c into cgocall.c. * Add very large comment describing cgo call sequences. * Simpilify, regularize cgo function implementations and names. * Add test suite as misc/cgo/test. Now the Go -> C path calls cgocall, which calls asmcgocall, and the C -> Go path calls cgocallback, which calls cgocallbackg. The shuffling, which affects mainly the callback case, moves most of the callback implementation to cgocallback running on the m->curg stack (not the m->g0 scheduler stack) and only while accounted for with $GOMAXPROCS (between calls to exitsyscall and entersyscall). The previous callback code did not block in startcgocallback's approximation to exitsyscall, so if, say, the garbage collector were running, it would still barge in and start doing things like call malloc. Similarly endcgocallback's approximation of entersyscall did not call matchmg to kick off new OS threads when necessary, which caused the bug in issue 1560. Fixes #1560. R=iant CC=golang-dev https://golang.org/cl/4253054
2011-03-07 08:37:42 -07:00
// This has the added benefit that it looks to the traceback
// routine like cgocallbackg is going to return to that
// PC (because the frame we allocate below has the same
// size as cgocallback_gofunc's frame declared above)
runtime: scheduler, cgo reorganization * Change use of m->g0 stack (aka scheduler stack). * Provide runtime.mcall(f) to invoke f() on m->g0 stack. * Replace scheduler loop entry with runtime.mcall(schedule). Runtime.mcall eliminates the need for fake scheduler states that exist just to run a bit of code on the m->g0 stack (Grecovery, Gstackalloc). The elimination of the scheduler as a loop that stops and starts using gosave and gogo fixes a bad interaction with the way cgo uses the m->g0 stack. Cgo runs external (gcc-compiled) C functions on that stack, and then when calling back into Go, it sets m->g0->sched.sp below the added call frames, so that other uses of m->g0's stack will not interfere with those frames. Unfortunately, gogo (longjmp) back to the scheduler loop at this point would end up running scheduler with the lower sp, which no longer points at a valid stack frame for a call to scheduler. If scheduler then wrote any function call arguments or local variables to where it expected the stack frame to be, it would overwrite other data on the stack. I realized this possibility while debugging a problem with calling complex Go code in a Go -> C -> Go cgo callback. This wasn't the bug I was looking for, it turns out, but I believe it is a real bug nonetheless. Switching to runtime.mcall, which only adds new frames to the stack and never jumps into functions running in existing ones, fixes this bug. * Move cgo-related code out of proc.c into cgocall.c. * Add very large comment describing cgo call sequences. * Simpilify, regularize cgo function implementations and names. * Add test suite as misc/cgo/test. Now the Go -> C path calls cgocall, which calls asmcgocall, and the C -> Go path calls cgocallback, which calls cgocallbackg. The shuffling, which affects mainly the callback case, moves most of the callback implementation to cgocallback running on the m->curg stack (not the m->g0 scheduler stack) and only while accounted for with $GOMAXPROCS (between calls to exitsyscall and entersyscall). The previous callback code did not block in startcgocallback's approximation to exitsyscall, so if, say, the garbage collector were running, it would still barge in and start doing things like call malloc. Similarly endcgocallback's approximation of entersyscall did not call matchmg to kick off new OS threads when necessary, which caused the bug in issue 1560. Fixes #1560. R=iant CC=golang-dev https://golang.org/cl/4253054
2011-03-07 08:37:42 -07:00
// so that the traceback will seamlessly trace back into
// the earlier calls.
//
// In the new goroutine, 0(SP) holds the saved R8.
MOVQ m_curg(BX), SI
runtime: scheduler, cgo reorganization * Change use of m->g0 stack (aka scheduler stack). * Provide runtime.mcall(f) to invoke f() on m->g0 stack. * Replace scheduler loop entry with runtime.mcall(schedule). Runtime.mcall eliminates the need for fake scheduler states that exist just to run a bit of code on the m->g0 stack (Grecovery, Gstackalloc). The elimination of the scheduler as a loop that stops and starts using gosave and gogo fixes a bad interaction with the way cgo uses the m->g0 stack. Cgo runs external (gcc-compiled) C functions on that stack, and then when calling back into Go, it sets m->g0->sched.sp below the added call frames, so that other uses of m->g0's stack will not interfere with those frames. Unfortunately, gogo (longjmp) back to the scheduler loop at this point would end up running scheduler with the lower sp, which no longer points at a valid stack frame for a call to scheduler. If scheduler then wrote any function call arguments or local variables to where it expected the stack frame to be, it would overwrite other data on the stack. I realized this possibility while debugging a problem with calling complex Go code in a Go -> C -> Go cgo callback. This wasn't the bug I was looking for, it turns out, but I believe it is a real bug nonetheless. Switching to runtime.mcall, which only adds new frames to the stack and never jumps into functions running in existing ones, fixes this bug. * Move cgo-related code out of proc.c into cgocall.c. * Add very large comment describing cgo call sequences. * Simpilify, regularize cgo function implementations and names. * Add test suite as misc/cgo/test. Now the Go -> C path calls cgocall, which calls asmcgocall, and the C -> Go path calls cgocallback, which calls cgocallbackg. The shuffling, which affects mainly the callback case, moves most of the callback implementation to cgocallback running on the m->curg stack (not the m->g0 scheduler stack) and only while accounted for with $GOMAXPROCS (between calls to exitsyscall and entersyscall). The previous callback code did not block in startcgocallback's approximation to exitsyscall, so if, say, the garbage collector were running, it would still barge in and start doing things like call malloc. Similarly endcgocallback's approximation of entersyscall did not call matchmg to kick off new OS threads when necessary, which caused the bug in issue 1560. Fixes #1560. R=iant CC=golang-dev https://golang.org/cl/4253054
2011-03-07 08:37:42 -07:00
MOVQ SI, g(CX)
MOVQ (g_sched+gobuf_sp)(SI), DI // prepare stack as DI
MOVQ (g_sched+gobuf_pc)(SI), BX
MOVQ BX, -8(DI)
// Compute the size of the frame, including return PC and, if
// GOEXPERIMENT=framepointer, the saved based pointer
LEAQ fv+0(FP), AX
SUBQ SP, AX
SUBQ AX, DI
MOVQ DI, SP
MOVQ R8, 0(SP)
runtime: scheduler, cgo reorganization * Change use of m->g0 stack (aka scheduler stack). * Provide runtime.mcall(f) to invoke f() on m->g0 stack. * Replace scheduler loop entry with runtime.mcall(schedule). Runtime.mcall eliminates the need for fake scheduler states that exist just to run a bit of code on the m->g0 stack (Grecovery, Gstackalloc). The elimination of the scheduler as a loop that stops and starts using gosave and gogo fixes a bad interaction with the way cgo uses the m->g0 stack. Cgo runs external (gcc-compiled) C functions on that stack, and then when calling back into Go, it sets m->g0->sched.sp below the added call frames, so that other uses of m->g0's stack will not interfere with those frames. Unfortunately, gogo (longjmp) back to the scheduler loop at this point would end up running scheduler with the lower sp, which no longer points at a valid stack frame for a call to scheduler. If scheduler then wrote any function call arguments or local variables to where it expected the stack frame to be, it would overwrite other data on the stack. I realized this possibility while debugging a problem with calling complex Go code in a Go -> C -> Go cgo callback. This wasn't the bug I was looking for, it turns out, but I believe it is a real bug nonetheless. Switching to runtime.mcall, which only adds new frames to the stack and never jumps into functions running in existing ones, fixes this bug. * Move cgo-related code out of proc.c into cgocall.c. * Add very large comment describing cgo call sequences. * Simpilify, regularize cgo function implementations and names. * Add test suite as misc/cgo/test. Now the Go -> C path calls cgocall, which calls asmcgocall, and the C -> Go path calls cgocallback, which calls cgocallbackg. The shuffling, which affects mainly the callback case, moves most of the callback implementation to cgocallback running on the m->curg stack (not the m->g0 scheduler stack) and only while accounted for with $GOMAXPROCS (between calls to exitsyscall and entersyscall). The previous callback code did not block in startcgocallback's approximation to exitsyscall, so if, say, the garbage collector were running, it would still barge in and start doing things like call malloc. Similarly endcgocallback's approximation of entersyscall did not call matchmg to kick off new OS threads when necessary, which caused the bug in issue 1560. Fixes #1560. R=iant CC=golang-dev https://golang.org/cl/4253054
2011-03-07 08:37:42 -07:00
CALL runtime·cgocallbackg(SB)
MOVQ 0(SP), R8
runtime: scheduler, cgo reorganization * Change use of m->g0 stack (aka scheduler stack). * Provide runtime.mcall(f) to invoke f() on m->g0 stack. * Replace scheduler loop entry with runtime.mcall(schedule). Runtime.mcall eliminates the need for fake scheduler states that exist just to run a bit of code on the m->g0 stack (Grecovery, Gstackalloc). The elimination of the scheduler as a loop that stops and starts using gosave and gogo fixes a bad interaction with the way cgo uses the m->g0 stack. Cgo runs external (gcc-compiled) C functions on that stack, and then when calling back into Go, it sets m->g0->sched.sp below the added call frames, so that other uses of m->g0's stack will not interfere with those frames. Unfortunately, gogo (longjmp) back to the scheduler loop at this point would end up running scheduler with the lower sp, which no longer points at a valid stack frame for a call to scheduler. If scheduler then wrote any function call arguments or local variables to where it expected the stack frame to be, it would overwrite other data on the stack. I realized this possibility while debugging a problem with calling complex Go code in a Go -> C -> Go cgo callback. This wasn't the bug I was looking for, it turns out, but I believe it is a real bug nonetheless. Switching to runtime.mcall, which only adds new frames to the stack and never jumps into functions running in existing ones, fixes this bug. * Move cgo-related code out of proc.c into cgocall.c. * Add very large comment describing cgo call sequences. * Simpilify, regularize cgo function implementations and names. * Add test suite as misc/cgo/test. Now the Go -> C path calls cgocall, which calls asmcgocall, and the C -> Go path calls cgocallback, which calls cgocallbackg. The shuffling, which affects mainly the callback case, moves most of the callback implementation to cgocallback running on the m->curg stack (not the m->g0 scheduler stack) and only while accounted for with $GOMAXPROCS (between calls to exitsyscall and entersyscall). The previous callback code did not block in startcgocallback's approximation to exitsyscall, so if, say, the garbage collector were running, it would still barge in and start doing things like call malloc. Similarly endcgocallback's approximation of entersyscall did not call matchmg to kick off new OS threads when necessary, which caused the bug in issue 1560. Fixes #1560. R=iant CC=golang-dev https://golang.org/cl/4253054
2011-03-07 08:37:42 -07:00
// Compute the size of the frame again. FP and SP have
// completely different values here than they did above,
// but only their difference matters.
LEAQ fv+0(FP), AX
SUBQ SP, AX
// Restore g->sched (== m->curg->sched) from saved values.
runtime: scheduler, cgo reorganization * Change use of m->g0 stack (aka scheduler stack). * Provide runtime.mcall(f) to invoke f() on m->g0 stack. * Replace scheduler loop entry with runtime.mcall(schedule). Runtime.mcall eliminates the need for fake scheduler states that exist just to run a bit of code on the m->g0 stack (Grecovery, Gstackalloc). The elimination of the scheduler as a loop that stops and starts using gosave and gogo fixes a bad interaction with the way cgo uses the m->g0 stack. Cgo runs external (gcc-compiled) C functions on that stack, and then when calling back into Go, it sets m->g0->sched.sp below the added call frames, so that other uses of m->g0's stack will not interfere with those frames. Unfortunately, gogo (longjmp) back to the scheduler loop at this point would end up running scheduler with the lower sp, which no longer points at a valid stack frame for a call to scheduler. If scheduler then wrote any function call arguments or local variables to where it expected the stack frame to be, it would overwrite other data on the stack. I realized this possibility while debugging a problem with calling complex Go code in a Go -> C -> Go cgo callback. This wasn't the bug I was looking for, it turns out, but I believe it is a real bug nonetheless. Switching to runtime.mcall, which only adds new frames to the stack and never jumps into functions running in existing ones, fixes this bug. * Move cgo-related code out of proc.c into cgocall.c. * Add very large comment describing cgo call sequences. * Simpilify, regularize cgo function implementations and names. * Add test suite as misc/cgo/test. Now the Go -> C path calls cgocall, which calls asmcgocall, and the C -> Go path calls cgocallback, which calls cgocallbackg. The shuffling, which affects mainly the callback case, moves most of the callback implementation to cgocallback running on the m->curg stack (not the m->g0 scheduler stack) and only while accounted for with $GOMAXPROCS (between calls to exitsyscall and entersyscall). The previous callback code did not block in startcgocallback's approximation to exitsyscall, so if, say, the garbage collector were running, it would still barge in and start doing things like call malloc. Similarly endcgocallback's approximation of entersyscall did not call matchmg to kick off new OS threads when necessary, which caused the bug in issue 1560. Fixes #1560. R=iant CC=golang-dev https://golang.org/cl/4253054
2011-03-07 08:37:42 -07:00
get_tls(CX)
MOVQ g(CX), SI
MOVQ SP, DI
ADDQ AX, DI
MOVQ -8(DI), BX
MOVQ BX, (g_sched+gobuf_pc)(SI)
runtime: scheduler, cgo reorganization * Change use of m->g0 stack (aka scheduler stack). * Provide runtime.mcall(f) to invoke f() on m->g0 stack. * Replace scheduler loop entry with runtime.mcall(schedule). Runtime.mcall eliminates the need for fake scheduler states that exist just to run a bit of code on the m->g0 stack (Grecovery, Gstackalloc). The elimination of the scheduler as a loop that stops and starts using gosave and gogo fixes a bad interaction with the way cgo uses the m->g0 stack. Cgo runs external (gcc-compiled) C functions on that stack, and then when calling back into Go, it sets m->g0->sched.sp below the added call frames, so that other uses of m->g0's stack will not interfere with those frames. Unfortunately, gogo (longjmp) back to the scheduler loop at this point would end up running scheduler with the lower sp, which no longer points at a valid stack frame for a call to scheduler. If scheduler then wrote any function call arguments or local variables to where it expected the stack frame to be, it would overwrite other data on the stack. I realized this possibility while debugging a problem with calling complex Go code in a Go -> C -> Go cgo callback. This wasn't the bug I was looking for, it turns out, but I believe it is a real bug nonetheless. Switching to runtime.mcall, which only adds new frames to the stack and never jumps into functions running in existing ones, fixes this bug. * Move cgo-related code out of proc.c into cgocall.c. * Add very large comment describing cgo call sequences. * Simpilify, regularize cgo function implementations and names. * Add test suite as misc/cgo/test. Now the Go -> C path calls cgocall, which calls asmcgocall, and the C -> Go path calls cgocallback, which calls cgocallbackg. The shuffling, which affects mainly the callback case, moves most of the callback implementation to cgocallback running on the m->curg stack (not the m->g0 scheduler stack) and only while accounted for with $GOMAXPROCS (between calls to exitsyscall and entersyscall). The previous callback code did not block in startcgocallback's approximation to exitsyscall, so if, say, the garbage collector were running, it would still barge in and start doing things like call malloc. Similarly endcgocallback's approximation of entersyscall did not call matchmg to kick off new OS threads when necessary, which caused the bug in issue 1560. Fixes #1560. R=iant CC=golang-dev https://golang.org/cl/4253054
2011-03-07 08:37:42 -07:00
MOVQ DI, (g_sched+gobuf_sp)(SI)
// Switch back to m->g0's stack and restore m->g0->sched.sp.
// (Unlike m->curg, the g0 goroutine never uses sched.pc,
// so we do not have to restore it.)
MOVQ g(CX), BX
MOVQ g_m(BX), BX
MOVQ m_g0(BX), SI
runtime: scheduler, cgo reorganization * Change use of m->g0 stack (aka scheduler stack). * Provide runtime.mcall(f) to invoke f() on m->g0 stack. * Replace scheduler loop entry with runtime.mcall(schedule). Runtime.mcall eliminates the need for fake scheduler states that exist just to run a bit of code on the m->g0 stack (Grecovery, Gstackalloc). The elimination of the scheduler as a loop that stops and starts using gosave and gogo fixes a bad interaction with the way cgo uses the m->g0 stack. Cgo runs external (gcc-compiled) C functions on that stack, and then when calling back into Go, it sets m->g0->sched.sp below the added call frames, so that other uses of m->g0's stack will not interfere with those frames. Unfortunately, gogo (longjmp) back to the scheduler loop at this point would end up running scheduler with the lower sp, which no longer points at a valid stack frame for a call to scheduler. If scheduler then wrote any function call arguments or local variables to where it expected the stack frame to be, it would overwrite other data on the stack. I realized this possibility while debugging a problem with calling complex Go code in a Go -> C -> Go cgo callback. This wasn't the bug I was looking for, it turns out, but I believe it is a real bug nonetheless. Switching to runtime.mcall, which only adds new frames to the stack and never jumps into functions running in existing ones, fixes this bug. * Move cgo-related code out of proc.c into cgocall.c. * Add very large comment describing cgo call sequences. * Simpilify, regularize cgo function implementations and names. * Add test suite as misc/cgo/test. Now the Go -> C path calls cgocall, which calls asmcgocall, and the C -> Go path calls cgocallback, which calls cgocallbackg. The shuffling, which affects mainly the callback case, moves most of the callback implementation to cgocallback running on the m->curg stack (not the m->g0 scheduler stack) and only while accounted for with $GOMAXPROCS (between calls to exitsyscall and entersyscall). The previous callback code did not block in startcgocallback's approximation to exitsyscall, so if, say, the garbage collector were running, it would still barge in and start doing things like call malloc. Similarly endcgocallback's approximation of entersyscall did not call matchmg to kick off new OS threads when necessary, which caused the bug in issue 1560. Fixes #1560. R=iant CC=golang-dev https://golang.org/cl/4253054
2011-03-07 08:37:42 -07:00
MOVQ SI, g(CX)
MOVQ (g_sched+gobuf_sp)(SI), SP
MOVQ 0(SP), AX
MOVQ AX, (g_sched+gobuf_sp)(SI)
// If the m on entry was nil, we called needm above to borrow an m
// for the duration of the call. Since the call is over, return it with dropm.
CMPQ R8, $0
JNE 3(PC)
MOVQ $runtime·dropm(SB), AX
CALL AX
runtime: scheduler, cgo reorganization * Change use of m->g0 stack (aka scheduler stack). * Provide runtime.mcall(f) to invoke f() on m->g0 stack. * Replace scheduler loop entry with runtime.mcall(schedule). Runtime.mcall eliminates the need for fake scheduler states that exist just to run a bit of code on the m->g0 stack (Grecovery, Gstackalloc). The elimination of the scheduler as a loop that stops and starts using gosave and gogo fixes a bad interaction with the way cgo uses the m->g0 stack. Cgo runs external (gcc-compiled) C functions on that stack, and then when calling back into Go, it sets m->g0->sched.sp below the added call frames, so that other uses of m->g0's stack will not interfere with those frames. Unfortunately, gogo (longjmp) back to the scheduler loop at this point would end up running scheduler with the lower sp, which no longer points at a valid stack frame for a call to scheduler. If scheduler then wrote any function call arguments or local variables to where it expected the stack frame to be, it would overwrite other data on the stack. I realized this possibility while debugging a problem with calling complex Go code in a Go -> C -> Go cgo callback. This wasn't the bug I was looking for, it turns out, but I believe it is a real bug nonetheless. Switching to runtime.mcall, which only adds new frames to the stack and never jumps into functions running in existing ones, fixes this bug. * Move cgo-related code out of proc.c into cgocall.c. * Add very large comment describing cgo call sequences. * Simpilify, regularize cgo function implementations and names. * Add test suite as misc/cgo/test. Now the Go -> C path calls cgocall, which calls asmcgocall, and the C -> Go path calls cgocallback, which calls cgocallbackg. The shuffling, which affects mainly the callback case, moves most of the callback implementation to cgocallback running on the m->curg stack (not the m->g0 scheduler stack) and only while accounted for with $GOMAXPROCS (between calls to exitsyscall and entersyscall). The previous callback code did not block in startcgocallback's approximation to exitsyscall, so if, say, the garbage collector were running, it would still barge in and start doing things like call malloc. Similarly endcgocallback's approximation of entersyscall did not call matchmg to kick off new OS threads when necessary, which caused the bug in issue 1560. Fixes #1560. R=iant CC=golang-dev https://golang.org/cl/4253054
2011-03-07 08:37:42 -07:00
// Done!
RET
2014-06-26 09:54:39 -06:00
// void setg(G*); set g. for use by needm.
cmd/cc, runtime: convert C compilers to use Go calling convention To date, the C compilers and Go compilers differed only in how values were returned from functions. This made it difficult to call Go from C or C from Go if return values were involved. It also made assembly called from Go and assembly called from C different. This CL changes the C compiler to use the Go conventions, passing results on the stack, after the arguments. [Exception: this does not apply to C ... functions, because you can't know where on the stack the arguments end.] By doing this, the CL makes it possible to rewrite C functions into Go one at a time, without worrying about which languages call that function or which languages it calls. This CL also updates all the assembly files in package runtime to use the new conventions. Argument references of the form 40(SP) have been rewritten to the form name+10(FP) instead, and there are now Go func prototypes for every assembly function called from C or Go. This means that 'go vet runtime' checks effectively every assembly function, and go vet's output was used to automate the bulk of the conversion. Some functions, like seek and nsec on Plan 9, needed to be rewritten. Many assembly routines called from C were reading arguments incorrectly, using MOVL instead of MOVQ or vice versa, especially on the less used systems like openbsd. These were found by go vet and have been corrected too. If we're lucky, this may reduce flakiness on those systems. Tested on: darwin/386 darwin/amd64 linux/arm linux/386 linux/amd64 If this breaks another system, the bug is almost certainly in the sys_$GOOS_$GOARCH.s file, since the rest of the CL is tested by the combination of the above systems. LGTM=dvyukov, iant R=golang-codereviews, 0intro, dave, alex.brainman, dvyukov, iant CC=golang-codereviews, josharian, r https://golang.org/cl/135830043
2014-08-27 09:32:17 -06:00
TEXT runtime·setg(SB), NOSPLIT, $0-8
2014-06-26 09:54:39 -06:00
MOVQ gg+0(FP), BX
#ifdef GOOS_windows
2014-06-26 09:54:39 -06:00
CMPQ BX, $0
JNE settls
MOVQ $0, 0x28(GS)
RET
settls:
2014-06-26 09:54:39 -06:00
MOVQ g_m(BX), AX
LEAQ m_tls(AX), AX
MOVQ AX, 0x28(GS)
#endif
get_tls(CX)
MOVQ BX, g(CX)
RET
2014-06-26 09:54:39 -06:00
// void setg_gcc(G*); set g called from gcc.
TEXT setg_gcc<>(SB),NOSPLIT,$0
get_tls(AX)
2014-06-26 09:54:39 -06:00
MOVQ DI, g(AX)
RET
// check that SP is in range [g->stack.lo, g->stack.hi)
TEXT runtime·stackcheck(SB), NOSPLIT, $0-0
get_tls(CX)
MOVQ g(CX), AX
CMPQ (g_stack+stack_hi)(AX), SP
JHI 2(PC)
INT $3
CMPQ SP, (g_stack+stack_lo)(AX)
JHI 2(PC)
INT $3
RET
runtime: implement GC stack barriers This commit implements stack barriers to minimize the amount of stack re-scanning that must be done during mark termination. Currently the GC scans stacks of active goroutines twice during every GC cycle: once at the beginning during root discovery and once at the end during mark termination. The second scan happens while the world is stopped and guarantees that we've seen all of the roots (since there are no write barriers on writes to local stack variables). However, this means pause time is proportional to stack size. In particularly recursive programs, this can drive pause time up past our 10ms goal (e.g., it takes about 150ms to scan a 50MB heap). Re-scanning the entire stack is rarely necessary, especially for large stacks, because usually most of the frames on the stack were not active between the first and second scans and hence any changes to these frames (via non-escaping pointers passed down the stack) were tracked by write barriers. To efficiently track how far a stack has been unwound since the first scan (and, hence, how much needs to be re-scanned), this commit introduces stack barriers. During the first scan, at exponentially spaced points in each stack, the scan overwrites return PCs with the PC of the stack barrier function. When "returned" to, the stack barrier function records how far the stack has unwound and jumps to the original return PC for that point in the stack. Then the second scan only needs to proceed as far as the lowest barrier that hasn't been hit. For deeply recursive programs, this substantially reduces mark termination time (and hence pause time). For the goscheme example linked in issue #10898, prior to this change, mark termination times were typically between 100 and 500ms; with this change, mark termination times are typically between 10 and 20ms. As a result of the reduced stack scanning work, this reduces overall execution time of the goscheme example by 20%. Fixes #10898. The effect of this on programs that are not deeply recursive is minimal: name old time/op new time/op delta BinaryTree17 3.16s ± 2% 3.26s ± 1% +3.31% (p=0.000 n=19+19) Fannkuch11 2.42s ± 1% 2.48s ± 1% +2.24% (p=0.000 n=17+19) FmtFprintfEmpty 50.0ns ± 3% 49.8ns ± 1% ~ (p=0.534 n=20+19) FmtFprintfString 173ns ± 0% 175ns ± 0% +1.49% (p=0.000 n=16+19) FmtFprintfInt 170ns ± 1% 175ns ± 1% +2.97% (p=0.000 n=20+19) FmtFprintfIntInt 288ns ± 0% 295ns ± 0% +2.73% (p=0.000 n=16+19) FmtFprintfPrefixedInt 242ns ± 1% 252ns ± 1% +4.13% (p=0.000 n=18+18) FmtFprintfFloat 324ns ± 0% 323ns ± 0% -0.36% (p=0.000 n=20+19) FmtManyArgs 1.14µs ± 0% 1.12µs ± 1% -1.01% (p=0.000 n=18+19) GobDecode 8.88ms ± 1% 8.87ms ± 0% ~ (p=0.480 n=19+18) GobEncode 6.80ms ± 1% 6.85ms ± 0% +0.82% (p=0.000 n=20+18) Gzip 363ms ± 1% 363ms ± 1% ~ (p=0.077 n=18+20) Gunzip 90.6ms ± 0% 90.0ms ± 1% -0.71% (p=0.000 n=17+18) HTTPClientServer 51.5µs ± 1% 50.8µs ± 1% -1.32% (p=0.000 n=18+18) JSONEncode 17.0ms ± 0% 17.1ms ± 0% +0.40% (p=0.000 n=18+17) JSONDecode 61.8ms ± 0% 63.8ms ± 1% +3.11% (p=0.000 n=18+17) Mandelbrot200 3.84ms ± 0% 3.84ms ± 1% ~ (p=0.583 n=19+19) GoParse 3.71ms ± 1% 3.72ms ± 1% ~ (p=0.159 n=18+19) RegexpMatchEasy0_32 100ns ± 0% 100ns ± 1% -0.19% (p=0.033 n=17+19) RegexpMatchEasy0_1K 342ns ± 1% 331ns ± 0% -3.41% (p=0.000 n=19+19) RegexpMatchEasy1_32 82.5ns ± 0% 81.7ns ± 0% -0.98% (p=0.000 n=18+18) RegexpMatchEasy1_1K 505ns ± 0% 494ns ± 1% -2.16% (p=0.000 n=18+18) RegexpMatchMedium_32 137ns ± 1% 137ns ± 1% -0.24% (p=0.048 n=20+18) RegexpMatchMedium_1K 41.6µs ± 0% 41.3µs ± 1% -0.57% (p=0.004 n=18+20) RegexpMatchHard_32 2.11µs ± 0% 2.11µs ± 1% +0.20% (p=0.037 n=17+19) RegexpMatchHard_1K 63.9µs ± 2% 63.3µs ± 0% -0.99% (p=0.000 n=20+17) Revcomp 560ms ± 1% 522ms ± 0% -6.87% (p=0.000 n=18+16) Template 75.0ms ± 0% 75.1ms ± 1% +0.18% (p=0.013 n=18+19) TimeParse 358ns ± 1% 364ns ± 0% +1.74% (p=0.000 n=20+15) TimeFormat 360ns ± 0% 372ns ± 0% +3.55% (p=0.000 n=20+18) Change-Id: If8a9bfae6c128d15a4f405e02bcfa50129df82a2 Reviewed-on: https://go-review.googlesource.com/10314 Reviewed-by: Russ Cox <rsc@golang.org> Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-05-20 14:30:49 -06:00
TEXT runtime·getcallerpc(SB),NOSPLIT,$8-16
cmd/cc, runtime: convert C compilers to use Go calling convention To date, the C compilers and Go compilers differed only in how values were returned from functions. This made it difficult to call Go from C or C from Go if return values were involved. It also made assembly called from Go and assembly called from C different. This CL changes the C compiler to use the Go conventions, passing results on the stack, after the arguments. [Exception: this does not apply to C ... functions, because you can't know where on the stack the arguments end.] By doing this, the CL makes it possible to rewrite C functions into Go one at a time, without worrying about which languages call that function or which languages it calls. This CL also updates all the assembly files in package runtime to use the new conventions. Argument references of the form 40(SP) have been rewritten to the form name+10(FP) instead, and there are now Go func prototypes for every assembly function called from C or Go. This means that 'go vet runtime' checks effectively every assembly function, and go vet's output was used to automate the bulk of the conversion. Some functions, like seek and nsec on Plan 9, needed to be rewritten. Many assembly routines called from C were reading arguments incorrectly, using MOVL instead of MOVQ or vice versa, especially on the less used systems like openbsd. These were found by go vet and have been corrected too. If we're lucky, this may reduce flakiness on those systems. Tested on: darwin/386 darwin/amd64 linux/arm linux/386 linux/amd64 If this breaks another system, the bug is almost certainly in the sys_$GOOS_$GOARCH.s file, since the rest of the CL is tested by the combination of the above systems. LGTM=dvyukov, iant R=golang-codereviews, 0intro, dave, alex.brainman, dvyukov, iant CC=golang-codereviews, josharian, r https://golang.org/cl/135830043
2014-08-27 09:32:17 -06:00
MOVQ argp+0(FP),AX // addr of first arg
MOVQ -8(AX),AX // get calling pc
runtime: implement GC stack barriers This commit implements stack barriers to minimize the amount of stack re-scanning that must be done during mark termination. Currently the GC scans stacks of active goroutines twice during every GC cycle: once at the beginning during root discovery and once at the end during mark termination. The second scan happens while the world is stopped and guarantees that we've seen all of the roots (since there are no write barriers on writes to local stack variables). However, this means pause time is proportional to stack size. In particularly recursive programs, this can drive pause time up past our 10ms goal (e.g., it takes about 150ms to scan a 50MB heap). Re-scanning the entire stack is rarely necessary, especially for large stacks, because usually most of the frames on the stack were not active between the first and second scans and hence any changes to these frames (via non-escaping pointers passed down the stack) were tracked by write barriers. To efficiently track how far a stack has been unwound since the first scan (and, hence, how much needs to be re-scanned), this commit introduces stack barriers. During the first scan, at exponentially spaced points in each stack, the scan overwrites return PCs with the PC of the stack barrier function. When "returned" to, the stack barrier function records how far the stack has unwound and jumps to the original return PC for that point in the stack. Then the second scan only needs to proceed as far as the lowest barrier that hasn't been hit. For deeply recursive programs, this substantially reduces mark termination time (and hence pause time). For the goscheme example linked in issue #10898, prior to this change, mark termination times were typically between 100 and 500ms; with this change, mark termination times are typically between 10 and 20ms. As a result of the reduced stack scanning work, this reduces overall execution time of the goscheme example by 20%. Fixes #10898. The effect of this on programs that are not deeply recursive is minimal: name old time/op new time/op delta BinaryTree17 3.16s ± 2% 3.26s ± 1% +3.31% (p=0.000 n=19+19) Fannkuch11 2.42s ± 1% 2.48s ± 1% +2.24% (p=0.000 n=17+19) FmtFprintfEmpty 50.0ns ± 3% 49.8ns ± 1% ~ (p=0.534 n=20+19) FmtFprintfString 173ns ± 0% 175ns ± 0% +1.49% (p=0.000 n=16+19) FmtFprintfInt 170ns ± 1% 175ns ± 1% +2.97% (p=0.000 n=20+19) FmtFprintfIntInt 288ns ± 0% 295ns ± 0% +2.73% (p=0.000 n=16+19) FmtFprintfPrefixedInt 242ns ± 1% 252ns ± 1% +4.13% (p=0.000 n=18+18) FmtFprintfFloat 324ns ± 0% 323ns ± 0% -0.36% (p=0.000 n=20+19) FmtManyArgs 1.14µs ± 0% 1.12µs ± 1% -1.01% (p=0.000 n=18+19) GobDecode 8.88ms ± 1% 8.87ms ± 0% ~ (p=0.480 n=19+18) GobEncode 6.80ms ± 1% 6.85ms ± 0% +0.82% (p=0.000 n=20+18) Gzip 363ms ± 1% 363ms ± 1% ~ (p=0.077 n=18+20) Gunzip 90.6ms ± 0% 90.0ms ± 1% -0.71% (p=0.000 n=17+18) HTTPClientServer 51.5µs ± 1% 50.8µs ± 1% -1.32% (p=0.000 n=18+18) JSONEncode 17.0ms ± 0% 17.1ms ± 0% +0.40% (p=0.000 n=18+17) JSONDecode 61.8ms ± 0% 63.8ms ± 1% +3.11% (p=0.000 n=18+17) Mandelbrot200 3.84ms ± 0% 3.84ms ± 1% ~ (p=0.583 n=19+19) GoParse 3.71ms ± 1% 3.72ms ± 1% ~ (p=0.159 n=18+19) RegexpMatchEasy0_32 100ns ± 0% 100ns ± 1% -0.19% (p=0.033 n=17+19) RegexpMatchEasy0_1K 342ns ± 1% 331ns ± 0% -3.41% (p=0.000 n=19+19) RegexpMatchEasy1_32 82.5ns ± 0% 81.7ns ± 0% -0.98% (p=0.000 n=18+18) RegexpMatchEasy1_1K 505ns ± 0% 494ns ± 1% -2.16% (p=0.000 n=18+18) RegexpMatchMedium_32 137ns ± 1% 137ns ± 1% -0.24% (p=0.048 n=20+18) RegexpMatchMedium_1K 41.6µs ± 0% 41.3µs ± 1% -0.57% (p=0.004 n=18+20) RegexpMatchHard_32 2.11µs ± 0% 2.11µs ± 1% +0.20% (p=0.037 n=17+19) RegexpMatchHard_1K 63.9µs ± 2% 63.3µs ± 0% -0.99% (p=0.000 n=20+17) Revcomp 560ms ± 1% 522ms ± 0% -6.87% (p=0.000 n=18+16) Template 75.0ms ± 0% 75.1ms ± 1% +0.18% (p=0.013 n=18+19) TimeParse 358ns ± 1% 364ns ± 0% +1.74% (p=0.000 n=20+15) TimeFormat 360ns ± 0% 372ns ± 0% +3.55% (p=0.000 n=20+18) Change-Id: If8a9bfae6c128d15a4f405e02bcfa50129df82a2 Reviewed-on: https://go-review.googlesource.com/10314 Reviewed-by: Russ Cox <rsc@golang.org> Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-05-20 14:30:49 -06:00
CMPQ AX, runtime·stackBarrierPC(SB)
JNE nobar
// Get original return PC.
CALL runtime·nextBarrierPC(SB)
MOVQ 0(SP), AX
nobar:
cmd/cc, runtime: convert C compilers to use Go calling convention To date, the C compilers and Go compilers differed only in how values were returned from functions. This made it difficult to call Go from C or C from Go if return values were involved. It also made assembly called from Go and assembly called from C different. This CL changes the C compiler to use the Go conventions, passing results on the stack, after the arguments. [Exception: this does not apply to C ... functions, because you can't know where on the stack the arguments end.] By doing this, the CL makes it possible to rewrite C functions into Go one at a time, without worrying about which languages call that function or which languages it calls. This CL also updates all the assembly files in package runtime to use the new conventions. Argument references of the form 40(SP) have been rewritten to the form name+10(FP) instead, and there are now Go func prototypes for every assembly function called from C or Go. This means that 'go vet runtime' checks effectively every assembly function, and go vet's output was used to automate the bulk of the conversion. Some functions, like seek and nsec on Plan 9, needed to be rewritten. Many assembly routines called from C were reading arguments incorrectly, using MOVL instead of MOVQ or vice versa, especially on the less used systems like openbsd. These were found by go vet and have been corrected too. If we're lucky, this may reduce flakiness on those systems. Tested on: darwin/386 darwin/amd64 linux/arm linux/386 linux/amd64 If this breaks another system, the bug is almost certainly in the sys_$GOOS_$GOARCH.s file, since the rest of the CL is tested by the combination of the above systems. LGTM=dvyukov, iant R=golang-codereviews, 0intro, dave, alex.brainman, dvyukov, iant CC=golang-codereviews, josharian, r https://golang.org/cl/135830043
2014-08-27 09:32:17 -06:00
MOVQ AX, ret+8(FP)
RET
runtime: implement GC stack barriers This commit implements stack barriers to minimize the amount of stack re-scanning that must be done during mark termination. Currently the GC scans stacks of active goroutines twice during every GC cycle: once at the beginning during root discovery and once at the end during mark termination. The second scan happens while the world is stopped and guarantees that we've seen all of the roots (since there are no write barriers on writes to local stack variables). However, this means pause time is proportional to stack size. In particularly recursive programs, this can drive pause time up past our 10ms goal (e.g., it takes about 150ms to scan a 50MB heap). Re-scanning the entire stack is rarely necessary, especially for large stacks, because usually most of the frames on the stack were not active between the first and second scans and hence any changes to these frames (via non-escaping pointers passed down the stack) were tracked by write barriers. To efficiently track how far a stack has been unwound since the first scan (and, hence, how much needs to be re-scanned), this commit introduces stack barriers. During the first scan, at exponentially spaced points in each stack, the scan overwrites return PCs with the PC of the stack barrier function. When "returned" to, the stack barrier function records how far the stack has unwound and jumps to the original return PC for that point in the stack. Then the second scan only needs to proceed as far as the lowest barrier that hasn't been hit. For deeply recursive programs, this substantially reduces mark termination time (and hence pause time). For the goscheme example linked in issue #10898, prior to this change, mark termination times were typically between 100 and 500ms; with this change, mark termination times are typically between 10 and 20ms. As a result of the reduced stack scanning work, this reduces overall execution time of the goscheme example by 20%. Fixes #10898. The effect of this on programs that are not deeply recursive is minimal: name old time/op new time/op delta BinaryTree17 3.16s ± 2% 3.26s ± 1% +3.31% (p=0.000 n=19+19) Fannkuch11 2.42s ± 1% 2.48s ± 1% +2.24% (p=0.000 n=17+19) FmtFprintfEmpty 50.0ns ± 3% 49.8ns ± 1% ~ (p=0.534 n=20+19) FmtFprintfString 173ns ± 0% 175ns ± 0% +1.49% (p=0.000 n=16+19) FmtFprintfInt 170ns ± 1% 175ns ± 1% +2.97% (p=0.000 n=20+19) FmtFprintfIntInt 288ns ± 0% 295ns ± 0% +2.73% (p=0.000 n=16+19) FmtFprintfPrefixedInt 242ns ± 1% 252ns ± 1% +4.13% (p=0.000 n=18+18) FmtFprintfFloat 324ns ± 0% 323ns ± 0% -0.36% (p=0.000 n=20+19) FmtManyArgs 1.14µs ± 0% 1.12µs ± 1% -1.01% (p=0.000 n=18+19) GobDecode 8.88ms ± 1% 8.87ms ± 0% ~ (p=0.480 n=19+18) GobEncode 6.80ms ± 1% 6.85ms ± 0% +0.82% (p=0.000 n=20+18) Gzip 363ms ± 1% 363ms ± 1% ~ (p=0.077 n=18+20) Gunzip 90.6ms ± 0% 90.0ms ± 1% -0.71% (p=0.000 n=17+18) HTTPClientServer 51.5µs ± 1% 50.8µs ± 1% -1.32% (p=0.000 n=18+18) JSONEncode 17.0ms ± 0% 17.1ms ± 0% +0.40% (p=0.000 n=18+17) JSONDecode 61.8ms ± 0% 63.8ms ± 1% +3.11% (p=0.000 n=18+17) Mandelbrot200 3.84ms ± 0% 3.84ms ± 1% ~ (p=0.583 n=19+19) GoParse 3.71ms ± 1% 3.72ms ± 1% ~ (p=0.159 n=18+19) RegexpMatchEasy0_32 100ns ± 0% 100ns ± 1% -0.19% (p=0.033 n=17+19) RegexpMatchEasy0_1K 342ns ± 1% 331ns ± 0% -3.41% (p=0.000 n=19+19) RegexpMatchEasy1_32 82.5ns ± 0% 81.7ns ± 0% -0.98% (p=0.000 n=18+18) RegexpMatchEasy1_1K 505ns ± 0% 494ns ± 1% -2.16% (p=0.000 n=18+18) RegexpMatchMedium_32 137ns ± 1% 137ns ± 1% -0.24% (p=0.048 n=20+18) RegexpMatchMedium_1K 41.6µs ± 0% 41.3µs ± 1% -0.57% (p=0.004 n=18+20) RegexpMatchHard_32 2.11µs ± 0% 2.11µs ± 1% +0.20% (p=0.037 n=17+19) RegexpMatchHard_1K 63.9µs ± 2% 63.3µs ± 0% -0.99% (p=0.000 n=20+17) Revcomp 560ms ± 1% 522ms ± 0% -6.87% (p=0.000 n=18+16) Template 75.0ms ± 0% 75.1ms ± 1% +0.18% (p=0.013 n=18+19) TimeParse 358ns ± 1% 364ns ± 0% +1.74% (p=0.000 n=20+15) TimeFormat 360ns ± 0% 372ns ± 0% +3.55% (p=0.000 n=20+18) Change-Id: If8a9bfae6c128d15a4f405e02bcfa50129df82a2 Reviewed-on: https://go-review.googlesource.com/10314 Reviewed-by: Russ Cox <rsc@golang.org> Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-05-20 14:30:49 -06:00
TEXT runtime·setcallerpc(SB),NOSPLIT,$8-16
cmd/cc, runtime: convert C compilers to use Go calling convention To date, the C compilers and Go compilers differed only in how values were returned from functions. This made it difficult to call Go from C or C from Go if return values were involved. It also made assembly called from Go and assembly called from C different. This CL changes the C compiler to use the Go conventions, passing results on the stack, after the arguments. [Exception: this does not apply to C ... functions, because you can't know where on the stack the arguments end.] By doing this, the CL makes it possible to rewrite C functions into Go one at a time, without worrying about which languages call that function or which languages it calls. This CL also updates all the assembly files in package runtime to use the new conventions. Argument references of the form 40(SP) have been rewritten to the form name+10(FP) instead, and there are now Go func prototypes for every assembly function called from C or Go. This means that 'go vet runtime' checks effectively every assembly function, and go vet's output was used to automate the bulk of the conversion. Some functions, like seek and nsec on Plan 9, needed to be rewritten. Many assembly routines called from C were reading arguments incorrectly, using MOVL instead of MOVQ or vice versa, especially on the less used systems like openbsd. These were found by go vet and have been corrected too. If we're lucky, this may reduce flakiness on those systems. Tested on: darwin/386 darwin/amd64 linux/arm linux/386 linux/amd64 If this breaks another system, the bug is almost certainly in the sys_$GOOS_$GOARCH.s file, since the rest of the CL is tested by the combination of the above systems. LGTM=dvyukov, iant R=golang-codereviews, 0intro, dave, alex.brainman, dvyukov, iant CC=golang-codereviews, josharian, r https://golang.org/cl/135830043
2014-08-27 09:32:17 -06:00
MOVQ argp+0(FP),AX // addr of first arg
MOVQ pc+8(FP), BX
runtime: implement GC stack barriers This commit implements stack barriers to minimize the amount of stack re-scanning that must be done during mark termination. Currently the GC scans stacks of active goroutines twice during every GC cycle: once at the beginning during root discovery and once at the end during mark termination. The second scan happens while the world is stopped and guarantees that we've seen all of the roots (since there are no write barriers on writes to local stack variables). However, this means pause time is proportional to stack size. In particularly recursive programs, this can drive pause time up past our 10ms goal (e.g., it takes about 150ms to scan a 50MB heap). Re-scanning the entire stack is rarely necessary, especially for large stacks, because usually most of the frames on the stack were not active between the first and second scans and hence any changes to these frames (via non-escaping pointers passed down the stack) were tracked by write barriers. To efficiently track how far a stack has been unwound since the first scan (and, hence, how much needs to be re-scanned), this commit introduces stack barriers. During the first scan, at exponentially spaced points in each stack, the scan overwrites return PCs with the PC of the stack barrier function. When "returned" to, the stack barrier function records how far the stack has unwound and jumps to the original return PC for that point in the stack. Then the second scan only needs to proceed as far as the lowest barrier that hasn't been hit. For deeply recursive programs, this substantially reduces mark termination time (and hence pause time). For the goscheme example linked in issue #10898, prior to this change, mark termination times were typically between 100 and 500ms; with this change, mark termination times are typically between 10 and 20ms. As a result of the reduced stack scanning work, this reduces overall execution time of the goscheme example by 20%. Fixes #10898. The effect of this on programs that are not deeply recursive is minimal: name old time/op new time/op delta BinaryTree17 3.16s ± 2% 3.26s ± 1% +3.31% (p=0.000 n=19+19) Fannkuch11 2.42s ± 1% 2.48s ± 1% +2.24% (p=0.000 n=17+19) FmtFprintfEmpty 50.0ns ± 3% 49.8ns ± 1% ~ (p=0.534 n=20+19) FmtFprintfString 173ns ± 0% 175ns ± 0% +1.49% (p=0.000 n=16+19) FmtFprintfInt 170ns ± 1% 175ns ± 1% +2.97% (p=0.000 n=20+19) FmtFprintfIntInt 288ns ± 0% 295ns ± 0% +2.73% (p=0.000 n=16+19) FmtFprintfPrefixedInt 242ns ± 1% 252ns ± 1% +4.13% (p=0.000 n=18+18) FmtFprintfFloat 324ns ± 0% 323ns ± 0% -0.36% (p=0.000 n=20+19) FmtManyArgs 1.14µs ± 0% 1.12µs ± 1% -1.01% (p=0.000 n=18+19) GobDecode 8.88ms ± 1% 8.87ms ± 0% ~ (p=0.480 n=19+18) GobEncode 6.80ms ± 1% 6.85ms ± 0% +0.82% (p=0.000 n=20+18) Gzip 363ms ± 1% 363ms ± 1% ~ (p=0.077 n=18+20) Gunzip 90.6ms ± 0% 90.0ms ± 1% -0.71% (p=0.000 n=17+18) HTTPClientServer 51.5µs ± 1% 50.8µs ± 1% -1.32% (p=0.000 n=18+18) JSONEncode 17.0ms ± 0% 17.1ms ± 0% +0.40% (p=0.000 n=18+17) JSONDecode 61.8ms ± 0% 63.8ms ± 1% +3.11% (p=0.000 n=18+17) Mandelbrot200 3.84ms ± 0% 3.84ms ± 1% ~ (p=0.583 n=19+19) GoParse 3.71ms ± 1% 3.72ms ± 1% ~ (p=0.159 n=18+19) RegexpMatchEasy0_32 100ns ± 0% 100ns ± 1% -0.19% (p=0.033 n=17+19) RegexpMatchEasy0_1K 342ns ± 1% 331ns ± 0% -3.41% (p=0.000 n=19+19) RegexpMatchEasy1_32 82.5ns ± 0% 81.7ns ± 0% -0.98% (p=0.000 n=18+18) RegexpMatchEasy1_1K 505ns ± 0% 494ns ± 1% -2.16% (p=0.000 n=18+18) RegexpMatchMedium_32 137ns ± 1% 137ns ± 1% -0.24% (p=0.048 n=20+18) RegexpMatchMedium_1K 41.6µs ± 0% 41.3µs ± 1% -0.57% (p=0.004 n=18+20) RegexpMatchHard_32 2.11µs ± 0% 2.11µs ± 1% +0.20% (p=0.037 n=17+19) RegexpMatchHard_1K 63.9µs ± 2% 63.3µs ± 0% -0.99% (p=0.000 n=20+17) Revcomp 560ms ± 1% 522ms ± 0% -6.87% (p=0.000 n=18+16) Template 75.0ms ± 0% 75.1ms ± 1% +0.18% (p=0.013 n=18+19) TimeParse 358ns ± 1% 364ns ± 0% +1.74% (p=0.000 n=20+15) TimeFormat 360ns ± 0% 372ns ± 0% +3.55% (p=0.000 n=20+18) Change-Id: If8a9bfae6c128d15a4f405e02bcfa50129df82a2 Reviewed-on: https://go-review.googlesource.com/10314 Reviewed-by: Russ Cox <rsc@golang.org> Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-05-20 14:30:49 -06:00
MOVQ -8(AX), CX
CMPQ CX, runtime·stackBarrierPC(SB)
JEQ setbar
MOVQ BX, -8(AX) // set calling pc
RET
runtime: implement GC stack barriers This commit implements stack barriers to minimize the amount of stack re-scanning that must be done during mark termination. Currently the GC scans stacks of active goroutines twice during every GC cycle: once at the beginning during root discovery and once at the end during mark termination. The second scan happens while the world is stopped and guarantees that we've seen all of the roots (since there are no write barriers on writes to local stack variables). However, this means pause time is proportional to stack size. In particularly recursive programs, this can drive pause time up past our 10ms goal (e.g., it takes about 150ms to scan a 50MB heap). Re-scanning the entire stack is rarely necessary, especially for large stacks, because usually most of the frames on the stack were not active between the first and second scans and hence any changes to these frames (via non-escaping pointers passed down the stack) were tracked by write barriers. To efficiently track how far a stack has been unwound since the first scan (and, hence, how much needs to be re-scanned), this commit introduces stack barriers. During the first scan, at exponentially spaced points in each stack, the scan overwrites return PCs with the PC of the stack barrier function. When "returned" to, the stack barrier function records how far the stack has unwound and jumps to the original return PC for that point in the stack. Then the second scan only needs to proceed as far as the lowest barrier that hasn't been hit. For deeply recursive programs, this substantially reduces mark termination time (and hence pause time). For the goscheme example linked in issue #10898, prior to this change, mark termination times were typically between 100 and 500ms; with this change, mark termination times are typically between 10 and 20ms. As a result of the reduced stack scanning work, this reduces overall execution time of the goscheme example by 20%. Fixes #10898. The effect of this on programs that are not deeply recursive is minimal: name old time/op new time/op delta BinaryTree17 3.16s ± 2% 3.26s ± 1% +3.31% (p=0.000 n=19+19) Fannkuch11 2.42s ± 1% 2.48s ± 1% +2.24% (p=0.000 n=17+19) FmtFprintfEmpty 50.0ns ± 3% 49.8ns ± 1% ~ (p=0.534 n=20+19) FmtFprintfString 173ns ± 0% 175ns ± 0% +1.49% (p=0.000 n=16+19) FmtFprintfInt 170ns ± 1% 175ns ± 1% +2.97% (p=0.000 n=20+19) FmtFprintfIntInt 288ns ± 0% 295ns ± 0% +2.73% (p=0.000 n=16+19) FmtFprintfPrefixedInt 242ns ± 1% 252ns ± 1% +4.13% (p=0.000 n=18+18) FmtFprintfFloat 324ns ± 0% 323ns ± 0% -0.36% (p=0.000 n=20+19) FmtManyArgs 1.14µs ± 0% 1.12µs ± 1% -1.01% (p=0.000 n=18+19) GobDecode 8.88ms ± 1% 8.87ms ± 0% ~ (p=0.480 n=19+18) GobEncode 6.80ms ± 1% 6.85ms ± 0% +0.82% (p=0.000 n=20+18) Gzip 363ms ± 1% 363ms ± 1% ~ (p=0.077 n=18+20) Gunzip 90.6ms ± 0% 90.0ms ± 1% -0.71% (p=0.000 n=17+18) HTTPClientServer 51.5µs ± 1% 50.8µs ± 1% -1.32% (p=0.000 n=18+18) JSONEncode 17.0ms ± 0% 17.1ms ± 0% +0.40% (p=0.000 n=18+17) JSONDecode 61.8ms ± 0% 63.8ms ± 1% +3.11% (p=0.000 n=18+17) Mandelbrot200 3.84ms ± 0% 3.84ms ± 1% ~ (p=0.583 n=19+19) GoParse 3.71ms ± 1% 3.72ms ± 1% ~ (p=0.159 n=18+19) RegexpMatchEasy0_32 100ns ± 0% 100ns ± 1% -0.19% (p=0.033 n=17+19) RegexpMatchEasy0_1K 342ns ± 1% 331ns ± 0% -3.41% (p=0.000 n=19+19) RegexpMatchEasy1_32 82.5ns ± 0% 81.7ns ± 0% -0.98% (p=0.000 n=18+18) RegexpMatchEasy1_1K 505ns ± 0% 494ns ± 1% -2.16% (p=0.000 n=18+18) RegexpMatchMedium_32 137ns ± 1% 137ns ± 1% -0.24% (p=0.048 n=20+18) RegexpMatchMedium_1K 41.6µs ± 0% 41.3µs ± 1% -0.57% (p=0.004 n=18+20) RegexpMatchHard_32 2.11µs ± 0% 2.11µs ± 1% +0.20% (p=0.037 n=17+19) RegexpMatchHard_1K 63.9µs ± 2% 63.3µs ± 0% -0.99% (p=0.000 n=20+17) Revcomp 560ms ± 1% 522ms ± 0% -6.87% (p=0.000 n=18+16) Template 75.0ms ± 0% 75.1ms ± 1% +0.18% (p=0.013 n=18+19) TimeParse 358ns ± 1% 364ns ± 0% +1.74% (p=0.000 n=20+15) TimeFormat 360ns ± 0% 372ns ± 0% +3.55% (p=0.000 n=20+18) Change-Id: If8a9bfae6c128d15a4f405e02bcfa50129df82a2 Reviewed-on: https://go-review.googlesource.com/10314 Reviewed-by: Russ Cox <rsc@golang.org> Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-05-20 14:30:49 -06:00
setbar:
// Set the stack barrier return PC.
MOVQ BX, 0(SP)
CALL runtime·setNextBarrierPC(SB)
RET
cmd/cc, runtime: convert C compilers to use Go calling convention To date, the C compilers and Go compilers differed only in how values were returned from functions. This made it difficult to call Go from C or C from Go if return values were involved. It also made assembly called from Go and assembly called from C different. This CL changes the C compiler to use the Go conventions, passing results on the stack, after the arguments. [Exception: this does not apply to C ... functions, because you can't know where on the stack the arguments end.] By doing this, the CL makes it possible to rewrite C functions into Go one at a time, without worrying about which languages call that function or which languages it calls. This CL also updates all the assembly files in package runtime to use the new conventions. Argument references of the form 40(SP) have been rewritten to the form name+10(FP) instead, and there are now Go func prototypes for every assembly function called from C or Go. This means that 'go vet runtime' checks effectively every assembly function, and go vet's output was used to automate the bulk of the conversion. Some functions, like seek and nsec on Plan 9, needed to be rewritten. Many assembly routines called from C were reading arguments incorrectly, using MOVL instead of MOVQ or vice versa, especially on the less used systems like openbsd. These were found by go vet and have been corrected too. If we're lucky, this may reduce flakiness on those systems. Tested on: darwin/386 darwin/amd64 linux/arm linux/386 linux/amd64 If this breaks another system, the bug is almost certainly in the sys_$GOOS_$GOARCH.s file, since the rest of the CL is tested by the combination of the above systems. LGTM=dvyukov, iant R=golang-codereviews, 0intro, dave, alex.brainman, dvyukov, iant CC=golang-codereviews, josharian, r https://golang.org/cl/135830043
2014-08-27 09:32:17 -06:00
TEXT runtime·getcallersp(SB),NOSPLIT,$0-16
MOVQ argp+0(FP), AX
MOVQ AX, ret+8(FP)
RET
// func cputicks() int64
TEXT runtime·cputicks(SB),NOSPLIT,$0-0
CMPB runtime·lfenceBeforeRdtsc(SB), $1
JNE mfence
BYTE $0x0f; BYTE $0xae; BYTE $0xe8 // LFENCE
JMP done
mfence:
BYTE $0x0f; BYTE $0xae; BYTE $0xf0 // MFENCE
done:
RDTSC
SHLQ $32, DX
ADDQ DX, AX
cmd/cc, runtime: convert C compilers to use Go calling convention To date, the C compilers and Go compilers differed only in how values were returned from functions. This made it difficult to call Go from C or C from Go if return values were involved. It also made assembly called from Go and assembly called from C different. This CL changes the C compiler to use the Go conventions, passing results on the stack, after the arguments. [Exception: this does not apply to C ... functions, because you can't know where on the stack the arguments end.] By doing this, the CL makes it possible to rewrite C functions into Go one at a time, without worrying about which languages call that function or which languages it calls. This CL also updates all the assembly files in package runtime to use the new conventions. Argument references of the form 40(SP) have been rewritten to the form name+10(FP) instead, and there are now Go func prototypes for every assembly function called from C or Go. This means that 'go vet runtime' checks effectively every assembly function, and go vet's output was used to automate the bulk of the conversion. Some functions, like seek and nsec on Plan 9, needed to be rewritten. Many assembly routines called from C were reading arguments incorrectly, using MOVL instead of MOVQ or vice versa, especially on the less used systems like openbsd. These were found by go vet and have been corrected too. If we're lucky, this may reduce flakiness on those systems. Tested on: darwin/386 darwin/amd64 linux/arm linux/386 linux/amd64 If this breaks another system, the bug is almost certainly in the sys_$GOOS_$GOARCH.s file, since the rest of the CL is tested by the combination of the above systems. LGTM=dvyukov, iant R=golang-codereviews, 0intro, dave, alex.brainman, dvyukov, iant CC=golang-codereviews, josharian, r https://golang.org/cl/135830043
2014-08-27 09:32:17 -06:00
MOVQ AX, ret+0(FP)
RET
// memhash_varlen(p unsafe.Pointer, h seed) uintptr
// redirects to memhash(p, h, size) using the size
// stored in the closure.
TEXT runtime·memhash_varlen(SB),NOSPLIT,$32-24
GO_ARGS
NO_LOCAL_POINTERS
MOVQ p+0(FP), AX
MOVQ h+8(FP), BX
MOVQ 8(DX), CX
MOVQ AX, 0(SP)
MOVQ BX, 8(SP)
MOVQ CX, 16(SP)
CALL runtime·memhash(SB)
MOVQ 24(SP), AX
MOVQ AX, ret+16(FP)
RET
// hash function using AES hardware instructions
TEXT runtime·aeshash(SB),NOSPLIT,$0-32
MOVQ p+0(FP), AX // ptr to data
MOVQ s+16(FP), CX // size
LEAQ ret+24(FP), DX
JMP runtime·aeshashbody(SB)
TEXT runtime·aeshashstr(SB),NOSPLIT,$0-24
MOVQ p+0(FP), AX // ptr to string struct
MOVQ 8(AX), CX // length of string
MOVQ (AX), AX // string data
LEAQ ret+16(FP), DX
JMP runtime·aeshashbody(SB)
// AX: data
// CX: length
// DX: address to put return value
TEXT runtime·aeshashbody(SB),NOSPLIT,$0-0
MOVQ h+8(FP), X6 // seed to low 64 bits of xmm6
PINSRQ $1, CX, X6 // size to high 64 bits of xmm6
PSHUFHW $0, X6, X6 // replace size with its low 2 bytes repeated 4 times
MOVO runtime·aeskeysched(SB), X7
CMPQ CX, $16
JB aes0to15
JE aes16
CMPQ CX, $32
JBE aes17to32
CMPQ CX, $64
JBE aes33to64
CMPQ CX, $128
JBE aes65to128
JMP aes129plus
aes0to15:
TESTQ CX, CX
JE aes0
ADDQ $16, AX
TESTW $0xff0, AX
JE endofpage
// 16 bytes loaded at this address won't cross
// a page boundary, so we can load it directly.
MOVOU -16(AX), X0
ADDQ CX, CX
MOVQ $masks<>(SB), AX
PAND (AX)(CX*8), X0
// scramble 3 times
AESENC X6, X0
AESENC X7, X0
AESENC X7, X0
MOVQ X0, (DX)
RET
endofpage:
// address ends in 1111xxxx. Might be up against
// a page boundary, so load ending at last byte.
// Then shift bytes down using pshufb.
MOVOU -32(AX)(CX*1), X0
ADDQ CX, CX
MOVQ $shifts<>(SB), AX
PSHUFB (AX)(CX*8), X0
AESENC X6, X0
AESENC X7, X0
AESENC X7, X0
MOVQ X0, (DX)
RET
aes0:
// return input seed
MOVQ h+8(FP), AX
MOVQ AX, (DX)
RET
aes16:
MOVOU (AX), X0
AESENC X6, X0
AESENC X7, X0
AESENC X7, X0
MOVQ X0, (DX)
RET
aes17to32:
// load data to be hashed
MOVOU (AX), X0
MOVOU -16(AX)(CX*1), X1
// scramble 3 times
AESENC X6, X0
AESENC runtime·aeskeysched+16(SB), X1
AESENC X7, X0
AESENC X7, X1
AESENC X7, X0
AESENC X7, X1
// combine results
PXOR X1, X0
MOVQ X0, (DX)
RET
aes33to64:
MOVOU (AX), X0
MOVOU 16(AX), X1
MOVOU -32(AX)(CX*1), X2
MOVOU -16(AX)(CX*1), X3
AESENC X6, X0
AESENC runtime·aeskeysched+16(SB), X1
AESENC runtime·aeskeysched+32(SB), X2
AESENC runtime·aeskeysched+48(SB), X3
AESENC X7, X0
AESENC X7, X1
AESENC X7, X2
AESENC X7, X3
AESENC X7, X0
AESENC X7, X1
AESENC X7, X2
AESENC X7, X3
PXOR X2, X0
PXOR X3, X1
PXOR X1, X0
MOVQ X0, (DX)
RET
aes65to128:
MOVOU (AX), X0
MOVOU 16(AX), X1
MOVOU 32(AX), X2
MOVOU 48(AX), X3
MOVOU -64(AX)(CX*1), X4
MOVOU -48(AX)(CX*1), X5
MOVOU -32(AX)(CX*1), X8
MOVOU -16(AX)(CX*1), X9
AESENC X6, X0
AESENC runtime·aeskeysched+16(SB), X1
AESENC runtime·aeskeysched+32(SB), X2
AESENC runtime·aeskeysched+48(SB), X3
AESENC runtime·aeskeysched+64(SB), X4
AESENC runtime·aeskeysched+80(SB), X5
AESENC runtime·aeskeysched+96(SB), X8
AESENC runtime·aeskeysched+112(SB), X9
AESENC X7, X0
AESENC X7, X1
AESENC X7, X2
AESENC X7, X3
AESENC X7, X4
AESENC X7, X5
AESENC X7, X8
AESENC X7, X9
AESENC X7, X0
AESENC X7, X1
AESENC X7, X2
AESENC X7, X3
AESENC X7, X4
AESENC X7, X5
AESENC X7, X8
AESENC X7, X9
PXOR X4, X0
PXOR X5, X1
PXOR X8, X2
PXOR X9, X3
PXOR X2, X0
PXOR X3, X1
PXOR X1, X0
MOVQ X0, (DX)
RET
aes129plus:
// start with last (possibly overlapping) block
MOVOU -128(AX)(CX*1), X0
MOVOU -112(AX)(CX*1), X1
MOVOU -96(AX)(CX*1), X2
MOVOU -80(AX)(CX*1), X3
MOVOU -64(AX)(CX*1), X4
MOVOU -48(AX)(CX*1), X5
MOVOU -32(AX)(CX*1), X8
MOVOU -16(AX)(CX*1), X9
// scramble state once
AESENC X6, X0
AESENC runtime·aeskeysched+16(SB), X1
AESENC runtime·aeskeysched+32(SB), X2
AESENC runtime·aeskeysched+48(SB), X3
AESENC runtime·aeskeysched+64(SB), X4
AESENC runtime·aeskeysched+80(SB), X5
AESENC runtime·aeskeysched+96(SB), X8
AESENC runtime·aeskeysched+112(SB), X9
// compute number of remaining 128-byte blocks
DECQ CX
SHRQ $7, CX
aesloop:
// scramble state, xor in a block
MOVOU (AX), X10
MOVOU 16(AX), X11
MOVOU 32(AX), X12
MOVOU 48(AX), X13
AESENC X10, X0
AESENC X11, X1
AESENC X12, X2
AESENC X13, X3
MOVOU 64(AX), X10
MOVOU 80(AX), X11
MOVOU 96(AX), X12
MOVOU 112(AX), X13
AESENC X10, X4
AESENC X11, X5
AESENC X12, X8
AESENC X13, X9
// scramble state
AESENC X7, X0
AESENC X7, X1
AESENC X7, X2
AESENC X7, X3
AESENC X7, X4
AESENC X7, X5
AESENC X7, X8
AESENC X7, X9
ADDQ $128, AX
DECQ CX
JNE aesloop
// 2 more scrambles to finish
AESENC X7, X0
AESENC X7, X1
AESENC X7, X2
AESENC X7, X3
AESENC X7, X4
AESENC X7, X5
AESENC X7, X8
AESENC X7, X9
AESENC X7, X0
AESENC X7, X1
AESENC X7, X2
AESENC X7, X3
AESENC X7, X4
AESENC X7, X5
AESENC X7, X8
AESENC X7, X9
PXOR X4, X0
PXOR X5, X1
PXOR X8, X2
PXOR X9, X3
PXOR X2, X0
PXOR X3, X1
PXOR X1, X0
MOVQ X0, (DX)
RET
TEXT runtime·aeshash32(SB),NOSPLIT,$0-24
MOVQ p+0(FP), AX // ptr to data
MOVQ h+8(FP), X0 // seed
PINSRD $2, (AX), X0 // data
AESENC runtime·aeskeysched+0(SB), X0
AESENC runtime·aeskeysched+16(SB), X0
AESENC runtime·aeskeysched+32(SB), X0
MOVQ X0, ret+16(FP)
RET
TEXT runtime·aeshash64(SB),NOSPLIT,$0-24
MOVQ p+0(FP), AX // ptr to data
MOVQ h+8(FP), X0 // seed
PINSRQ $1, (AX), X0 // data
AESENC runtime·aeskeysched+0(SB), X0
AESENC runtime·aeskeysched+16(SB), X0
AESENC runtime·aeskeysched+32(SB), X0
MOVQ X0, ret+16(FP)
RET
// simple mask to get rid of data in the high part of the register.
DATA masks<>+0x00(SB)/8, $0x0000000000000000
DATA masks<>+0x08(SB)/8, $0x0000000000000000
DATA masks<>+0x10(SB)/8, $0x00000000000000ff
DATA masks<>+0x18(SB)/8, $0x0000000000000000
DATA masks<>+0x20(SB)/8, $0x000000000000ffff
DATA masks<>+0x28(SB)/8, $0x0000000000000000
DATA masks<>+0x30(SB)/8, $0x0000000000ffffff
DATA masks<>+0x38(SB)/8, $0x0000000000000000
DATA masks<>+0x40(SB)/8, $0x00000000ffffffff
DATA masks<>+0x48(SB)/8, $0x0000000000000000
DATA masks<>+0x50(SB)/8, $0x000000ffffffffff
DATA masks<>+0x58(SB)/8, $0x0000000000000000
DATA masks<>+0x60(SB)/8, $0x0000ffffffffffff
DATA masks<>+0x68(SB)/8, $0x0000000000000000
DATA masks<>+0x70(SB)/8, $0x00ffffffffffffff
DATA masks<>+0x78(SB)/8, $0x0000000000000000
DATA masks<>+0x80(SB)/8, $0xffffffffffffffff
DATA masks<>+0x88(SB)/8, $0x0000000000000000
DATA masks<>+0x90(SB)/8, $0xffffffffffffffff
DATA masks<>+0x98(SB)/8, $0x00000000000000ff
DATA masks<>+0xa0(SB)/8, $0xffffffffffffffff
DATA masks<>+0xa8(SB)/8, $0x000000000000ffff
DATA masks<>+0xb0(SB)/8, $0xffffffffffffffff
DATA masks<>+0xb8(SB)/8, $0x0000000000ffffff
DATA masks<>+0xc0(SB)/8, $0xffffffffffffffff
DATA masks<>+0xc8(SB)/8, $0x00000000ffffffff
DATA masks<>+0xd0(SB)/8, $0xffffffffffffffff
DATA masks<>+0xd8(SB)/8, $0x000000ffffffffff
DATA masks<>+0xe0(SB)/8, $0xffffffffffffffff
DATA masks<>+0xe8(SB)/8, $0x0000ffffffffffff
DATA masks<>+0xf0(SB)/8, $0xffffffffffffffff
DATA masks<>+0xf8(SB)/8, $0x00ffffffffffffff
GLOBL masks<>(SB),RODATA,$256
// these are arguments to pshufb. They move data down from
// the high bytes of the register to the low bytes of the register.
// index is how many bytes to move.
DATA shifts<>+0x00(SB)/8, $0x0000000000000000
DATA shifts<>+0x08(SB)/8, $0x0000000000000000
DATA shifts<>+0x10(SB)/8, $0xffffffffffffff0f
DATA shifts<>+0x18(SB)/8, $0xffffffffffffffff
DATA shifts<>+0x20(SB)/8, $0xffffffffffff0f0e
DATA shifts<>+0x28(SB)/8, $0xffffffffffffffff
DATA shifts<>+0x30(SB)/8, $0xffffffffff0f0e0d
DATA shifts<>+0x38(SB)/8, $0xffffffffffffffff
DATA shifts<>+0x40(SB)/8, $0xffffffff0f0e0d0c
DATA shifts<>+0x48(SB)/8, $0xffffffffffffffff
DATA shifts<>+0x50(SB)/8, $0xffffff0f0e0d0c0b
DATA shifts<>+0x58(SB)/8, $0xffffffffffffffff
DATA shifts<>+0x60(SB)/8, $0xffff0f0e0d0c0b0a
DATA shifts<>+0x68(SB)/8, $0xffffffffffffffff
DATA shifts<>+0x70(SB)/8, $0xff0f0e0d0c0b0a09
DATA shifts<>+0x78(SB)/8, $0xffffffffffffffff
DATA shifts<>+0x80(SB)/8, $0x0f0e0d0c0b0a0908
DATA shifts<>+0x88(SB)/8, $0xffffffffffffffff
DATA shifts<>+0x90(SB)/8, $0x0e0d0c0b0a090807
DATA shifts<>+0x98(SB)/8, $0xffffffffffffff0f
DATA shifts<>+0xa0(SB)/8, $0x0d0c0b0a09080706
DATA shifts<>+0xa8(SB)/8, $0xffffffffffff0f0e
DATA shifts<>+0xb0(SB)/8, $0x0c0b0a0908070605
DATA shifts<>+0xb8(SB)/8, $0xffffffffff0f0e0d
DATA shifts<>+0xc0(SB)/8, $0x0b0a090807060504
DATA shifts<>+0xc8(SB)/8, $0xffffffff0f0e0d0c
DATA shifts<>+0xd0(SB)/8, $0x0a09080706050403
DATA shifts<>+0xd8(SB)/8, $0xffffff0f0e0d0c0b
DATA shifts<>+0xe0(SB)/8, $0x0908070605040302
DATA shifts<>+0xe8(SB)/8, $0xffff0f0e0d0c0b0a
DATA shifts<>+0xf0(SB)/8, $0x0807060504030201
DATA shifts<>+0xf8(SB)/8, $0xff0f0e0d0c0b0a09
GLOBL shifts<>(SB),RODATA,$256
TEXT runtime·memeq(SB),NOSPLIT,$0-25
MOVQ a+0(FP), SI
MOVQ b+8(FP), DI
MOVQ size+16(FP), BX
LEAQ ret+24(FP), AX
JMP runtime·memeqbody(SB)
// memequal_varlen(a, b unsafe.Pointer) bool
TEXT runtime·memequal_varlen(SB),NOSPLIT,$0-17
MOVQ a+0(FP), SI
MOVQ b+8(FP), DI
CMPQ SI, DI
JEQ eq
MOVQ 8(DX), BX // compiler stores size at offset 8 in the closure
LEAQ ret+16(FP), AX
JMP runtime·memeqbody(SB)
eq:
MOVB $1, ret+16(FP)
RET
// eqstring tests whether two strings are equal.
// The compiler guarantees that strings passed
// to eqstring have equal length.
// See runtime_test.go:eqstring_generic for
// equivalent Go code.
TEXT runtime·eqstring(SB),NOSPLIT,$0-33
MOVQ s1str+0(FP), SI
MOVQ s2str+16(FP), DI
CMPQ SI, DI
JEQ eq
MOVQ s1len+8(FP), BX
LEAQ v+32(FP), AX
JMP runtime·memeqbody(SB)
eq:
MOVB $1, v+32(FP)
RET
// a in SI
// b in DI
// count in BX
// address of result byte in AX
TEXT runtime·memeqbody(SB),NOSPLIT,$0-0
CMPQ BX, $8
JB small
// 64 bytes at a time using xmm registers
hugeloop:
CMPQ BX, $64
JB bigloop
MOVOU (SI), X0
MOVOU (DI), X1
MOVOU 16(SI), X2
MOVOU 16(DI), X3
MOVOU 32(SI), X4
MOVOU 32(DI), X5
MOVOU 48(SI), X6
MOVOU 48(DI), X7
PCMPEQB X1, X0
PCMPEQB X3, X2
PCMPEQB X5, X4
PCMPEQB X7, X6
PAND X2, X0
PAND X6, X4
PAND X4, X0
PMOVMSKB X0, DX
ADDQ $64, SI
ADDQ $64, DI
SUBQ $64, BX
CMPL DX, $0xffff
JEQ hugeloop
MOVB $0, (AX)
RET
// 8 bytes at a time using 64-bit register
bigloop:
CMPQ BX, $8
JBE leftover
MOVQ (SI), CX
MOVQ (DI), DX
ADDQ $8, SI
ADDQ $8, DI
SUBQ $8, BX
CMPQ CX, DX
JEQ bigloop
MOVB $0, (AX)
RET
// remaining 0-8 bytes
leftover:
MOVQ -8(SI)(BX*1), CX
MOVQ -8(DI)(BX*1), DX
CMPQ CX, DX
SETEQ (AX)
RET
small:
CMPQ BX, $0
JEQ equal
LEAQ 0(BX*8), CX
NEGQ CX
CMPB SI, $0xf8
JA si_high
// load at SI won't cross a page boundary.
MOVQ (SI), SI
JMP si_finish
si_high:
// address ends in 11111xxx. Load up to bytes we want, move to correct position.
MOVQ -8(SI)(BX*1), SI
SHRQ CX, SI
si_finish:
// same for DI.
CMPB DI, $0xf8
JA di_high
MOVQ (DI), DI
JMP di_finish
di_high:
MOVQ -8(DI)(BX*1), DI
SHRQ CX, DI
di_finish:
SUBQ SI, DI
SHLQ CX, DI
equal:
SETEQ (AX)
RET
TEXT runtime·cmpstring(SB),NOSPLIT,$0-40
cmd/cc, runtime: convert C compilers to use Go calling convention To date, the C compilers and Go compilers differed only in how values were returned from functions. This made it difficult to call Go from C or C from Go if return values were involved. It also made assembly called from Go and assembly called from C different. This CL changes the C compiler to use the Go conventions, passing results on the stack, after the arguments. [Exception: this does not apply to C ... functions, because you can't know where on the stack the arguments end.] By doing this, the CL makes it possible to rewrite C functions into Go one at a time, without worrying about which languages call that function or which languages it calls. This CL also updates all the assembly files in package runtime to use the new conventions. Argument references of the form 40(SP) have been rewritten to the form name+10(FP) instead, and there are now Go func prototypes for every assembly function called from C or Go. This means that 'go vet runtime' checks effectively every assembly function, and go vet's output was used to automate the bulk of the conversion. Some functions, like seek and nsec on Plan 9, needed to be rewritten. Many assembly routines called from C were reading arguments incorrectly, using MOVL instead of MOVQ or vice versa, especially on the less used systems like openbsd. These were found by go vet and have been corrected too. If we're lucky, this may reduce flakiness on those systems. Tested on: darwin/386 darwin/amd64 linux/arm linux/386 linux/amd64 If this breaks another system, the bug is almost certainly in the sys_$GOOS_$GOARCH.s file, since the rest of the CL is tested by the combination of the above systems. LGTM=dvyukov, iant R=golang-codereviews, 0intro, dave, alex.brainman, dvyukov, iant CC=golang-codereviews, josharian, r https://golang.org/cl/135830043
2014-08-27 09:32:17 -06:00
MOVQ s1_base+0(FP), SI
MOVQ s1_len+8(FP), BX
MOVQ s2_base+16(FP), DI
MOVQ s2_len+24(FP), DX
LEAQ ret+32(FP), R9
JMP runtime·cmpbody(SB)
TEXT bytes·Compare(SB),NOSPLIT,$0-56
MOVQ s1+0(FP), SI
MOVQ s1+8(FP), BX
MOVQ s2+24(FP), DI
MOVQ s2+32(FP), DX
LEAQ res+48(FP), R9
JMP runtime·cmpbody(SB)
// input:
// SI = a
// DI = b
// BX = alen
// DX = blen
// R9 = address of output word (stores -1/0/1 here)
TEXT runtime·cmpbody(SB),NOSPLIT,$0-0
CMPQ SI, DI
JEQ allsame
CMPQ BX, DX
MOVQ DX, R8
CMOVQLT BX, R8 // R8 = min(alen, blen) = # of bytes to compare
CMPQ R8, $8
JB small
loop:
CMPQ R8, $16
JBE _0through16
MOVOU (SI), X0
MOVOU (DI), X1
PCMPEQB X0, X1
PMOVMSKB X1, AX
XORQ $0xffff, AX // convert EQ to NE
JNE diff16 // branch if at least one byte is not equal
ADDQ $16, SI
ADDQ $16, DI
SUBQ $16, R8
JMP loop
// AX = bit mask of differences
diff16:
BSFQ AX, BX // index of first byte that differs
XORQ AX, AX
MOVB (SI)(BX*1), CX
CMPB CX, (DI)(BX*1)
SETHI AX
LEAQ -1(AX*2), AX // convert 1/0 to +1/-1
MOVQ AX, (R9)
RET
// 0 through 16 bytes left, alen>=8, blen>=8
_0through16:
CMPQ R8, $8
JBE _0through8
MOVQ (SI), AX
MOVQ (DI), CX
CMPQ AX, CX
JNE diff8
_0through8:
MOVQ -8(SI)(R8*1), AX
MOVQ -8(DI)(R8*1), CX
CMPQ AX, CX
JEQ allsame
// AX and CX contain parts of a and b that differ.
diff8:
BSWAPQ AX // reverse order of bytes
BSWAPQ CX
XORQ AX, CX
BSRQ CX, CX // index of highest bit difference
SHRQ CX, AX // move a's bit to bottom
ANDQ $1, AX // mask bit
LEAQ -1(AX*2), AX // 1/0 => +1/-1
MOVQ AX, (R9)
RET
// 0-7 bytes in common
small:
LEAQ (R8*8), CX // bytes left -> bits left
NEGQ CX // - bits lift (== 64 - bits left mod 64)
JEQ allsame
// load bytes of a into high bytes of AX
CMPB SI, $0xf8
JA si_high
MOVQ (SI), SI
JMP si_finish
si_high:
MOVQ -8(SI)(R8*1), SI
SHRQ CX, SI
si_finish:
SHLQ CX, SI
// load bytes of b in to high bytes of BX
CMPB DI, $0xf8
JA di_high
MOVQ (DI), DI
JMP di_finish
di_high:
MOVQ -8(DI)(R8*1), DI
SHRQ CX, DI
di_finish:
SHLQ CX, DI
BSWAPQ SI // reverse order of bytes
BSWAPQ DI
XORQ SI, DI // find bit differences
JEQ allsame
BSRQ DI, CX // index of highest bit difference
SHRQ CX, SI // move a's bit to bottom
ANDQ $1, SI // mask bit
LEAQ -1(SI*2), AX // 1/0 => +1/-1
MOVQ AX, (R9)
RET
allsame:
XORQ AX, AX
XORQ CX, CX
CMPQ BX, DX
SETGT AX // 1 if alen > blen
SETEQ CX // 1 if alen == blen
LEAQ -1(CX)(AX*2), AX // 1,0,-1 result
MOVQ AX, (R9)
RET
TEXT bytes·IndexByte(SB),NOSPLIT,$0-40
MOVQ s+0(FP), SI
MOVQ s_len+8(FP), BX
MOVB c+24(FP), AL
LEAQ ret+32(FP), R8
JMP runtime·indexbytebody(SB)
TEXT strings·IndexByte(SB),NOSPLIT,$0-32
MOVQ s+0(FP), SI
MOVQ s_len+8(FP), BX
MOVB c+16(FP), AL
LEAQ ret+24(FP), R8
JMP runtime·indexbytebody(SB)
// input:
// SI: data
// BX: data len
// AL: byte sought
// R8: address to put result
TEXT runtime·indexbytebody(SB),NOSPLIT,$0
MOVQ SI, DI
CMPQ BX, $16
JLT small
// round up to first 16-byte boundary
TESTQ $15, SI
JZ aligned
MOVQ SI, CX
ANDQ $~15, CX
ADDQ $16, CX
// search the beginning
SUBQ SI, CX
REPN; SCASB
JZ success
// DI is 16-byte aligned; get ready to search using SSE instructions
aligned:
// round down to last 16-byte boundary
MOVQ BX, R11
ADDQ SI, R11
ANDQ $~15, R11
// shuffle X0 around so that each byte contains c
MOVD AX, X0
PUNPCKLBW X0, X0
PUNPCKLBW X0, X0
PSHUFL $0, X0, X0
JMP condition
sse:
// move the next 16-byte chunk of the buffer into X1
MOVO (DI), X1
// compare bytes in X0 to X1
PCMPEQB X0, X1
// take the top bit of each byte in X1 and put the result in DX
PMOVMSKB X1, DX
TESTL DX, DX
JNZ ssesuccess
ADDQ $16, DI
condition:
CMPQ DI, R11
JLT sse
// search the end
MOVQ SI, CX
ADDQ BX, CX
SUBQ R11, CX
// if CX == 0, the zero flag will be set and we'll end up
// returning a false success
JZ failure
REPN; SCASB
JZ success
failure:
MOVQ $-1, (R8)
RET
// handle for lengths < 16
small:
MOVQ BX, CX
REPN; SCASB
JZ success
MOVQ $-1, (R8)
RET
// we've found the chunk containing the byte
// now just figure out which specific byte it is
ssesuccess:
// get the index of the least significant set bit
BSFW DX, DX
SUBQ SI, DI
ADDQ DI, DX
MOVQ DX, (R8)
RET
success:
SUBQ SI, DI
SUBL $1, DI
MOVQ DI, (R8)
RET
TEXT bytes·Equal(SB),NOSPLIT,$0-49
MOVQ a_len+8(FP), BX
MOVQ b_len+32(FP), CX
CMPQ BX, CX
JNE eqret
MOVQ a+0(FP), SI
MOVQ b+24(FP), DI
LEAQ ret+48(FP), AX
JMP runtime·memeqbody(SB)
eqret:
MOVB $0, ret+48(FP)
RET
TEXT runtime·fastrand1(SB), NOSPLIT, $0-4
get_tls(CX)
MOVQ g(CX), AX
MOVQ g_m(AX), AX
MOVL m_fastrand(AX), DX
ADDL DX, DX
MOVL DX, BX
XORL $0x88888eef, DX
CMOVLMI BX, DX
MOVL DX, m_fastrand(AX)
MOVL DX, ret+0(FP)
RET
TEXT runtime·return0(SB), NOSPLIT, $0
MOVL $0, AX
RET
// Called from cgo wrappers, this function returns g->m->curg.stack.hi.
// Must obey the gcc calling convention.
TEXT _cgo_topofstack(SB),NOSPLIT,$0
get_tls(CX)
MOVQ g(CX), AX
MOVQ g_m(AX), AX
MOVQ m_curg(AX), AX
MOVQ (g_stack+stack_hi)(AX), AX
RET
// The top-most function running on a goroutine
// returns to goexit+PCQuantum.
TEXT runtime·goexit(SB),NOSPLIT,$0-0
BYTE $0x90 // NOP
CALL runtime·goexit1(SB) // does not return
// traceback from goexit1 must hit code range of goexit
BYTE $0x90 // NOP
TEXT runtime·prefetcht0(SB),NOSPLIT,$0-8
MOVQ addr+0(FP), AX
PREFETCHT0 (AX)
RET
TEXT runtime·prefetcht1(SB),NOSPLIT,$0-8
MOVQ addr+0(FP), AX
PREFETCHT1 (AX)
RET
TEXT runtime·prefetcht2(SB),NOSPLIT,$0-8
MOVQ addr+0(FP), AX
PREFETCHT2 (AX)
RET
TEXT runtime·prefetchnta(SB),NOSPLIT,$0-8
MOVQ addr+0(FP), AX
PREFETCHNTA (AX)
RET
// This is called from .init_array and follows the platform, not Go, ABI.
TEXT runtime·addmoduledata(SB),NOSPLIT,$0-0
PUSHQ R15 // The access to global variables below implicitly uses R15, which is callee-save
MOVQ runtime·lastmoduledatap(SB), AX
MOVQ DI, moduledata_next(AX)
MOVQ DI, runtime·lastmoduledatap(SB)
POPQ R15
RET