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go/src/runtime/asm_ppc64x.s

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// Copyright 2014 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.
// +build ppc64 ppc64le
#include "go_asm.h"
#include "go_tls.h"
#include "funcdata.h"
#include "textflag.h"
#include "asm_ppc64x.h"
TEXT runtime·rt0_go(SB),NOSPLIT,$0
// R1 = stack; R3 = argc; R4 = argv; R13 = C TLS base pointer
// initialize essential registers
BL runtime·reginit(SB)
SUB $(FIXED_FRAME+16), R1
cmd/compile, cmd/link, runtime: on ppc64x, maintain the TOC pointer in R2 when compiling PIC The PowerPC ISA does not have a PC-relative load instruction, which poses obvious challenges when generating position-independent code. The way the ELFv2 ABI addresses this is to specify that r2 points to a per "module" (shared library or executable) TOC pointer. Maintaining this pointer requires cooperation between codegen and the system linker: * Non-leaf functions leave space on the stack at r1+24 to save the TOC pointer. * A call to a function that *might* have to go via a PLT stub must be followed by a nop instruction that the system linker can replace with "ld r1, 24(r1)" to restore the TOC pointer (only when dynamically linking Go code). * When calling a function via a function pointer, the address of the function must be in r12, and the first couple of instructions (the "global entry point") of the called function use this to derive the address of the TOC for the module it is in. * When calling a function that is implemented in the same module, the system linker adjusts the call to skip over the instructions mentioned above (the "local entry point"), assuming that r2 is already correctly set. So this changeset adds the global entry point instructions, sets the metadata so the system linker knows where the local entry point is, inserts code to save the TOC pointer at 24(r1), adds a nop after any call not known to be local and copes with the odd non-local code transfer in the runtime (e.g. the stuff around jmpdefer). It does not actually compile PIC yet. Change-Id: I7522e22bdfd2f891745a900c60254fe9e372c854 Reviewed-on: https://go-review.googlesource.com/15967 Reviewed-by: Russ Cox <rsc@golang.org>
2015-10-15 20:42:09 -06:00
MOVD R2, 24(R1) // stash the TOC pointer away again now we've created a new frame
MOVW R3, FIXED_FRAME+0(R1) // argc
MOVD R4, FIXED_FRAME+8(R1) // argv
// create istack out of the given (operating system) stack.
// _cgo_init may update stackguard.
MOVD $runtime·g0(SB), g
MOVD $(-64*1024), R31
ADD R31, R1, R3
MOVD R3, g_stackguard0(g)
MOVD R3, g_stackguard1(g)
MOVD R3, (g_stack+stack_lo)(g)
MOVD R1, (g_stack+stack_hi)(g)
// if there is a _cgo_init, call it using the gcc ABI.
MOVD _cgo_init(SB), R12
CMP R0, R12
BEQ nocgo
MOVD R12, CTR // r12 = "global function entry point"
MOVD R13, R5 // arg 2: TLS base pointer
MOVD $setg_gcc<>(SB), R4 // arg 1: setg
MOVD g, R3 // arg 0: G
// C functions expect 32 bytes of space on caller stack frame
// and a 16-byte aligned R1
MOVD R1, R14 // save current stack
SUB $32, R1 // reserve 32 bytes
RLDCR $0, R1, $~15, R1 // 16-byte align
BL (CTR) // may clobber R0, R3-R12
MOVD R14, R1 // restore stack
cmd/compile, cmd/link, runtime: on ppc64x, maintain the TOC pointer in R2 when compiling PIC The PowerPC ISA does not have a PC-relative load instruction, which poses obvious challenges when generating position-independent code. The way the ELFv2 ABI addresses this is to specify that r2 points to a per "module" (shared library or executable) TOC pointer. Maintaining this pointer requires cooperation between codegen and the system linker: * Non-leaf functions leave space on the stack at r1+24 to save the TOC pointer. * A call to a function that *might* have to go via a PLT stub must be followed by a nop instruction that the system linker can replace with "ld r1, 24(r1)" to restore the TOC pointer (only when dynamically linking Go code). * When calling a function via a function pointer, the address of the function must be in r12, and the first couple of instructions (the "global entry point") of the called function use this to derive the address of the TOC for the module it is in. * When calling a function that is implemented in the same module, the system linker adjusts the call to skip over the instructions mentioned above (the "local entry point"), assuming that r2 is already correctly set. So this changeset adds the global entry point instructions, sets the metadata so the system linker knows where the local entry point is, inserts code to save the TOC pointer at 24(r1), adds a nop after any call not known to be local and copes with the odd non-local code transfer in the runtime (e.g. the stuff around jmpdefer). It does not actually compile PIC yet. Change-Id: I7522e22bdfd2f891745a900c60254fe9e372c854 Reviewed-on: https://go-review.googlesource.com/15967 Reviewed-by: Russ Cox <rsc@golang.org>
2015-10-15 20:42:09 -06:00
MOVD 24(R1), R2
XOR R0, R0 // fix R0
nocgo:
// update stackguard after _cgo_init
MOVD (g_stack+stack_lo)(g), R3
ADD $const__StackGuard, R3
MOVD R3, g_stackguard0(g)
MOVD R3, g_stackguard1(g)
// set the per-goroutine and per-mach "registers"
MOVD $runtime·m0(SB), R3
// save m->g0 = g0
MOVD g, m_g0(R3)
// save m0 to g0->m
MOVD R3, g_m(g)
BL runtime·check(SB)
// args are already prepared
BL runtime·args(SB)
BL runtime·osinit(SB)
BL runtime·schedinit(SB)
// create a new goroutine to start program
MOVD $runtime·mainPC(SB), R3 // entry
MOVDU R3, -8(R1)
MOVDU R0, -8(R1)
MOVDU R0, -8(R1)
MOVDU R0, -8(R1)
MOVDU R0, -8(R1)
MOVDU R0, -8(R1)
BL runtime·newproc(SB)
ADD $(16+FIXED_FRAME), R1
// start this M
BL runtime·mstart(SB)
MOVD R0, 1(R0)
RET
DATA runtime·mainPC+0(SB)/8,$runtime·main(SB)
GLOBL runtime·mainPC(SB),RODATA,$8
TEXT runtime·breakpoint(SB),NOSPLIT|NOFRAME,$0-0
MOVD R0, 2(R0) // TODO: TD
RET
TEXT runtime·asminit(SB),NOSPLIT|NOFRAME,$0-0
RET
TEXT _cgo_reginit(SB),NOSPLIT|NOFRAME,$0-0
// crosscall_ppc64 and crosscall2 need to reginit, but can't
// get at the 'runtime.reginit' symbol.
BR runtime·reginit(SB)
TEXT runtime·reginit(SB),NOSPLIT|NOFRAME,$0-0
// set R0 to zero, it's expected by the toolchain
XOR R0, R0
// initialize essential FP registers
FMOVD $4503601774854144.0, F27
FMOVD $0.5, F29
FSUB F29, F29, F28
FADD F29, F29, F30
FADD F30, F30, F31
RET
/*
* go-routine
*/
// void gosave(Gobuf*)
// save state in Gobuf; setjmp
TEXT runtime·gosave(SB), NOSPLIT|NOFRAME, $0-8
MOVD buf+0(FP), R3
MOVD R1, gobuf_sp(R3)
MOVD LR, R31
MOVD R31, gobuf_pc(R3)
MOVD g, gobuf_g(R3)
MOVD R0, gobuf_lr(R3)
MOVD R0, gobuf_ret(R3)
MOVD R0, gobuf_ctxt(R3)
RET
// void gogo(Gobuf*)
// restore state from Gobuf; longjmp
TEXT runtime·gogo(SB), NOSPLIT|NOFRAME, $0-8
MOVD buf+0(FP), R5
MOVD gobuf_g(R5), g // make sure g is not nil
BL runtime·save_g(SB)
MOVD 0(g), R4
MOVD gobuf_sp(R5), R1
MOVD gobuf_lr(R5), R31
MOVD R31, LR
MOVD gobuf_ret(R5), R3
MOVD gobuf_ctxt(R5), R11
MOVD R0, gobuf_sp(R5)
MOVD R0, gobuf_ret(R5)
MOVD R0, gobuf_lr(R5)
MOVD R0, gobuf_ctxt(R5)
CMP R0, R0 // set condition codes for == test, needed by stack split
MOVD gobuf_pc(R5), R12
MOVD R12, CTR
BR (CTR)
// void mcall(fn func(*g))
// Switch to m->g0's stack, call fn(g).
// Fn must never return. It should gogo(&g->sched)
// to keep running g.
TEXT runtime·mcall(SB), NOSPLIT|NOFRAME, $0-8
// Save caller state in g->sched
MOVD R1, (g_sched+gobuf_sp)(g)
MOVD LR, R31
MOVD R31, (g_sched+gobuf_pc)(g)
MOVD R0, (g_sched+gobuf_lr)(g)
MOVD g, (g_sched+gobuf_g)(g)
// Switch to m->g0 & its stack, call fn.
MOVD g, R3
MOVD g_m(g), R8
MOVD m_g0(R8), g
BL runtime·save_g(SB)
CMP g, R3
BNE 2(PC)
BR runtime·badmcall(SB)
MOVD fn+0(FP), R11 // context
MOVD 0(R11), R12 // code pointer
MOVD R12, CTR
MOVD (g_sched+gobuf_sp)(g), R1 // sp = m->g0->sched.sp
MOVDU R3, -8(R1)
MOVDU R0, -8(R1)
MOVDU R0, -8(R1)
MOVDU R0, -8(R1)
MOVDU R0, -8(R1)
BL (CTR)
cmd/compile, cmd/link, runtime: on ppc64x, maintain the TOC pointer in R2 when compiling PIC The PowerPC ISA does not have a PC-relative load instruction, which poses obvious challenges when generating position-independent code. The way the ELFv2 ABI addresses this is to specify that r2 points to a per "module" (shared library or executable) TOC pointer. Maintaining this pointer requires cooperation between codegen and the system linker: * Non-leaf functions leave space on the stack at r1+24 to save the TOC pointer. * A call to a function that *might* have to go via a PLT stub must be followed by a nop instruction that the system linker can replace with "ld r1, 24(r1)" to restore the TOC pointer (only when dynamically linking Go code). * When calling a function via a function pointer, the address of the function must be in r12, and the first couple of instructions (the "global entry point") of the called function use this to derive the address of the TOC for the module it is in. * When calling a function that is implemented in the same module, the system linker adjusts the call to skip over the instructions mentioned above (the "local entry point"), assuming that r2 is already correctly set. So this changeset adds the global entry point instructions, sets the metadata so the system linker knows where the local entry point is, inserts code to save the TOC pointer at 24(r1), adds a nop after any call not known to be local and copes with the odd non-local code transfer in the runtime (e.g. the stuff around jmpdefer). It does not actually compile PIC yet. Change-Id: I7522e22bdfd2f891745a900c60254fe9e372c854 Reviewed-on: https://go-review.googlesource.com/15967 Reviewed-by: Russ Cox <rsc@golang.org>
2015-10-15 20:42:09 -06:00
MOVD 24(R1), R2
BR runtime·badmcall2(SB)
// 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
// 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
cmd/compile, cmd/link, runtime: on ppc64x, maintain the TOC pointer in R2 when compiling PIC The PowerPC ISA does not have a PC-relative load instruction, which poses obvious challenges when generating position-independent code. The way the ELFv2 ABI addresses this is to specify that r2 points to a per "module" (shared library or executable) TOC pointer. Maintaining this pointer requires cooperation between codegen and the system linker: * Non-leaf functions leave space on the stack at r1+24 to save the TOC pointer. * A call to a function that *might* have to go via a PLT stub must be followed by a nop instruction that the system linker can replace with "ld r1, 24(r1)" to restore the TOC pointer (only when dynamically linking Go code). * When calling a function via a function pointer, the address of the function must be in r12, and the first couple of instructions (the "global entry point") of the called function use this to derive the address of the TOC for the module it is in. * When calling a function that is implemented in the same module, the system linker adjusts the call to skip over the instructions mentioned above (the "local entry point"), assuming that r2 is already correctly set. So this changeset adds the global entry point instructions, sets the metadata so the system linker knows where the local entry point is, inserts code to save the TOC pointer at 24(r1), adds a nop after any call not known to be local and copes with the odd non-local code transfer in the runtime (e.g. the stuff around jmpdefer). It does not actually compile PIC yet. Change-Id: I7522e22bdfd2f891745a900c60254fe9e372c854 Reviewed-on: https://go-review.googlesource.com/15967 Reviewed-by: Russ Cox <rsc@golang.org>
2015-10-15 20:42:09 -06:00
// We have several undefs here so that 16 bytes past
// $runtime·systemstack_switch lies within them whether or not the
// instructions that derive r2 from r12 are there.
UNDEF
UNDEF
UNDEF
BL (LR) // make sure this function is not leaf
RET
// func systemstack(fn func())
TEXT runtime·systemstack(SB), NOSPLIT, $0-8
MOVD fn+0(FP), R3 // R3 = fn
MOVD R3, R11 // context
MOVD g_m(g), R4 // R4 = m
MOVD m_gsignal(R4), R5 // R5 = gsignal
CMP g, R5
BEQ noswitch
MOVD m_g0(R4), R5 // R5 = g0
CMP g, R5
BEQ noswitch
MOVD m_curg(R4), R6
CMP g, R6
BEQ switch
// Bad: g is not gsignal, not g0, not curg. What is it?
// Hide call from linker nosplit analysis.
MOVD $runtime·badsystemstack(SB), R12
MOVD R12, CTR
BL (CTR)
switch:
// save our state in g->sched. Pretend to
// be systemstack_switch if the G stack is scanned.
MOVD $runtime·systemstack_switch(SB), R6
cmd/compile, cmd/link, runtime: on ppc64x, maintain the TOC pointer in R2 when compiling PIC The PowerPC ISA does not have a PC-relative load instruction, which poses obvious challenges when generating position-independent code. The way the ELFv2 ABI addresses this is to specify that r2 points to a per "module" (shared library or executable) TOC pointer. Maintaining this pointer requires cooperation between codegen and the system linker: * Non-leaf functions leave space on the stack at r1+24 to save the TOC pointer. * A call to a function that *might* have to go via a PLT stub must be followed by a nop instruction that the system linker can replace with "ld r1, 24(r1)" to restore the TOC pointer (only when dynamically linking Go code). * When calling a function via a function pointer, the address of the function must be in r12, and the first couple of instructions (the "global entry point") of the called function use this to derive the address of the TOC for the module it is in. * When calling a function that is implemented in the same module, the system linker adjusts the call to skip over the instructions mentioned above (the "local entry point"), assuming that r2 is already correctly set. So this changeset adds the global entry point instructions, sets the metadata so the system linker knows where the local entry point is, inserts code to save the TOC pointer at 24(r1), adds a nop after any call not known to be local and copes with the odd non-local code transfer in the runtime (e.g. the stuff around jmpdefer). It does not actually compile PIC yet. Change-Id: I7522e22bdfd2f891745a900c60254fe9e372c854 Reviewed-on: https://go-review.googlesource.com/15967 Reviewed-by: Russ Cox <rsc@golang.org>
2015-10-15 20:42:09 -06:00
ADD $16, R6 // get past prologue (including r2-setting instructions when they're there)
MOVD R6, (g_sched+gobuf_pc)(g)
MOVD R1, (g_sched+gobuf_sp)(g)
MOVD R0, (g_sched+gobuf_lr)(g)
MOVD g, (g_sched+gobuf_g)(g)
// switch to g0
MOVD R5, g
BL runtime·save_g(SB)
MOVD (g_sched+gobuf_sp)(g), R3
// make it look like mstart called systemstack on g0, to stop traceback
SUB $FIXED_FRAME, R3
MOVD $runtime·mstart(SB), R4
MOVD R4, 0(R3)
MOVD R3, R1
// call target function
MOVD 0(R11), R12 // code pointer
MOVD R12, CTR
BL (CTR)
cmd/compile, cmd/link, runtime: on ppc64x, maintain the TOC pointer in R2 when compiling PIC The PowerPC ISA does not have a PC-relative load instruction, which poses obvious challenges when generating position-independent code. The way the ELFv2 ABI addresses this is to specify that r2 points to a per "module" (shared library or executable) TOC pointer. Maintaining this pointer requires cooperation between codegen and the system linker: * Non-leaf functions leave space on the stack at r1+24 to save the TOC pointer. * A call to a function that *might* have to go via a PLT stub must be followed by a nop instruction that the system linker can replace with "ld r1, 24(r1)" to restore the TOC pointer (only when dynamically linking Go code). * When calling a function via a function pointer, the address of the function must be in r12, and the first couple of instructions (the "global entry point") of the called function use this to derive the address of the TOC for the module it is in. * When calling a function that is implemented in the same module, the system linker adjusts the call to skip over the instructions mentioned above (the "local entry point"), assuming that r2 is already correctly set. So this changeset adds the global entry point instructions, sets the metadata so the system linker knows where the local entry point is, inserts code to save the TOC pointer at 24(r1), adds a nop after any call not known to be local and copes with the odd non-local code transfer in the runtime (e.g. the stuff around jmpdefer). It does not actually compile PIC yet. Change-Id: I7522e22bdfd2f891745a900c60254fe9e372c854 Reviewed-on: https://go-review.googlesource.com/15967 Reviewed-by: Russ Cox <rsc@golang.org>
2015-10-15 20:42:09 -06:00
// restore TOC pointer. It seems unlikely that we will use systemstack
// to call a function defined in another module, but the results of
// doing so would be so confusing that it's worth doing this.
MOVD g_m(g), R3
MOVD m_curg(R3), g
MOVD (g_sched+gobuf_sp)(g), R3
MOVD 24(R3), R2
// switch back to g
MOVD g_m(g), R3
MOVD m_curg(R3), g
BL runtime·save_g(SB)
MOVD (g_sched+gobuf_sp)(g), R1
MOVD R0, (g_sched+gobuf_sp)(g)
RET
noswitch:
// already on m stack, just call directly
MOVD 0(R11), R12 // code pointer
MOVD R12, CTR
BL (CTR)
cmd/compile, cmd/link, runtime: on ppc64x, maintain the TOC pointer in R2 when compiling PIC The PowerPC ISA does not have a PC-relative load instruction, which poses obvious challenges when generating position-independent code. The way the ELFv2 ABI addresses this is to specify that r2 points to a per "module" (shared library or executable) TOC pointer. Maintaining this pointer requires cooperation between codegen and the system linker: * Non-leaf functions leave space on the stack at r1+24 to save the TOC pointer. * A call to a function that *might* have to go via a PLT stub must be followed by a nop instruction that the system linker can replace with "ld r1, 24(r1)" to restore the TOC pointer (only when dynamically linking Go code). * When calling a function via a function pointer, the address of the function must be in r12, and the first couple of instructions (the "global entry point") of the called function use this to derive the address of the TOC for the module it is in. * When calling a function that is implemented in the same module, the system linker adjusts the call to skip over the instructions mentioned above (the "local entry point"), assuming that r2 is already correctly set. So this changeset adds the global entry point instructions, sets the metadata so the system linker knows where the local entry point is, inserts code to save the TOC pointer at 24(r1), adds a nop after any call not known to be local and copes with the odd non-local code transfer in the runtime (e.g. the stuff around jmpdefer). It does not actually compile PIC yet. Change-Id: I7522e22bdfd2f891745a900c60254fe9e372c854 Reviewed-on: https://go-review.googlesource.com/15967 Reviewed-by: Russ Cox <rsc@golang.org>
2015-10-15 20:42:09 -06:00
MOVD 24(R1), R2
RET
/*
* support for morestack
*/
// Called during function prolog when more stack is needed.
// Caller has already loaded:
// R3: framesize, R4: argsize, R5: LR
//
// 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|NOFRAME,$0-0
// Cannot grow scheduler stack (m->g0).
MOVD g_m(g), R7
MOVD m_g0(R7), R8
CMP g, R8
BNE 2(PC)
BL runtime·abort(SB)
// Cannot grow signal stack (m->gsignal).
MOVD m_gsignal(R7), R8
CMP g, R8
BNE 2(PC)
BL runtime·abort(SB)
// Called from f.
// Set g->sched to context in f.
MOVD R11, (g_sched+gobuf_ctxt)(g)
MOVD R1, (g_sched+gobuf_sp)(g)
MOVD LR, R8
MOVD R8, (g_sched+gobuf_pc)(g)
MOVD R5, (g_sched+gobuf_lr)(g)
// Called from f.
// Set m->morebuf to f's caller.
MOVD R5, (m_morebuf+gobuf_pc)(R7) // f's caller's PC
MOVD R1, (m_morebuf+gobuf_sp)(R7) // f's caller's SP
MOVD g, (m_morebuf+gobuf_g)(R7)
// Call newstack on m->g0's stack.
MOVD m_g0(R7), g
BL runtime·save_g(SB)
MOVD (g_sched+gobuf_sp)(g), R1
BL runtime·newstack(SB)
// Not reached, but make sure the return PC from the call to newstack
// is still in this function, and not the beginning of the next.
UNDEF
TEXT runtime·morestack_noctxt(SB),NOSPLIT|NOFRAME,$0-0
MOVD R0, R11
BR 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 LR.
// R3 may be live. Other registers are available.
// Get the original return PC, g.stkbar[g.stkbarPos].savedLRVal.
MOVD (g_stkbar+slice_array)(g), R4
MOVD g_stkbarPos(g), R5
MOVD $stkbar__size, R6
MULLD R5, R6
ADD R4, R6
MOVD stkbar_savedLRVal(R6), R6
// Record that this stack barrier was hit.
ADD $1, R5
MOVD R5, g_stkbarPos(g)
// Jump to the original return PC.
MOVD R6, CTR
BR (CTR)
// 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) \
MOVD $MAXSIZE, R31; \
CMP R3, R31; \
BGT 4(PC); \
MOVD $NAME(SB), R12; \
MOVD R12, CTR; \
BR (CTR)
// Note: can't just "BR NAME(SB)" - bad inlining results.
TEXT reflect·call(SB), NOSPLIT, $0-0
BR ·reflectcall(SB)
TEXT ·reflectcall(SB), NOSPLIT|NOFRAME, $0-32
MOVWZ argsize+24(FP), R3
// 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)
MOVD $runtime·badreflectcall(SB), R12
MOVD R12, CTR
BR (CTR)
#define CALLFN(NAME,MAXSIZE) \
TEXT NAME(SB), WRAPPER, $MAXSIZE-24; \
NO_LOCAL_POINTERS; \
/* copy arguments to stack */ \
MOVD arg+16(FP), R3; \
MOVWZ argsize+24(FP), R4; \
MOVD R1, R5; \
ADD $(FIXED_FRAME-1), R5; \
SUB $1, R3; \
ADD R5, R4; \
CMP R5, R4; \
BEQ 4(PC); \
MOVBZU 1(R3), R6; \
MOVBZU R6, 1(R5); \
BR -4(PC); \
/* call function */ \
MOVD f+8(FP), R11; \
MOVD (R11), R12; \
MOVD R12, CTR; \
PCDATA $PCDATA_StackMapIndex, $0; \
BL (CTR); \
cmd/compile, cmd/link, runtime: on ppc64x, maintain the TOC pointer in R2 when compiling PIC The PowerPC ISA does not have a PC-relative load instruction, which poses obvious challenges when generating position-independent code. The way the ELFv2 ABI addresses this is to specify that r2 points to a per "module" (shared library or executable) TOC pointer. Maintaining this pointer requires cooperation between codegen and the system linker: * Non-leaf functions leave space on the stack at r1+24 to save the TOC pointer. * A call to a function that *might* have to go via a PLT stub must be followed by a nop instruction that the system linker can replace with "ld r1, 24(r1)" to restore the TOC pointer (only when dynamically linking Go code). * When calling a function via a function pointer, the address of the function must be in r12, and the first couple of instructions (the "global entry point") of the called function use this to derive the address of the TOC for the module it is in. * When calling a function that is implemented in the same module, the system linker adjusts the call to skip over the instructions mentioned above (the "local entry point"), assuming that r2 is already correctly set. So this changeset adds the global entry point instructions, sets the metadata so the system linker knows where the local entry point is, inserts code to save the TOC pointer at 24(r1), adds a nop after any call not known to be local and copes with the odd non-local code transfer in the runtime (e.g. the stuff around jmpdefer). It does not actually compile PIC yet. Change-Id: I7522e22bdfd2f891745a900c60254fe9e372c854 Reviewed-on: https://go-review.googlesource.com/15967 Reviewed-by: Russ Cox <rsc@golang.org>
2015-10-15 20:42:09 -06:00
MOVD 24(R1), R2; \
/* copy return values back */ \
MOVD arg+16(FP), R3; \
MOVWZ n+24(FP), R4; \
MOVWZ retoffset+28(FP), R6; \
MOVD R1, R5; \
ADD R6, R5; \
ADD R6, R3; \
SUB R6, R4; \
ADD $(FIXED_FRAME-1), R5; \
SUB $1, R3; \
ADD R5, R4; \
loop: \
CMP R5, R4; \
BEQ end; \
MOVBZU 1(R5), R6; \
MOVBZU R6, 1(R3); \
BR loop; \
end: \
/* execute write barrier updates */ \
MOVD argtype+0(FP), R7; \
MOVD arg+16(FP), R3; \
MOVWZ n+24(FP), R4; \
MOVWZ retoffset+28(FP), R6; \
MOVD R7, FIXED_FRAME+0(R1); \
MOVD R3, FIXED_FRAME+8(R1); \
MOVD R4, FIXED_FRAME+16(R1); \
MOVD R6, FIXED_FRAME+24(R1); \
BL 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)
TEXT runtime·procyield(SB),NOSPLIT,$0-0
RET
// void jmpdefer(fv, sp);
// called from deferreturn.
// 1. grab stored LR for caller
cmd/compile, cmd/link, runtime: on ppc64x, maintain the TOC pointer in R2 when compiling PIC The PowerPC ISA does not have a PC-relative load instruction, which poses obvious challenges when generating position-independent code. The way the ELFv2 ABI addresses this is to specify that r2 points to a per "module" (shared library or executable) TOC pointer. Maintaining this pointer requires cooperation between codegen and the system linker: * Non-leaf functions leave space on the stack at r1+24 to save the TOC pointer. * A call to a function that *might* have to go via a PLT stub must be followed by a nop instruction that the system linker can replace with "ld r1, 24(r1)" to restore the TOC pointer (only when dynamically linking Go code). * When calling a function via a function pointer, the address of the function must be in r12, and the first couple of instructions (the "global entry point") of the called function use this to derive the address of the TOC for the module it is in. * When calling a function that is implemented in the same module, the system linker adjusts the call to skip over the instructions mentioned above (the "local entry point"), assuming that r2 is already correctly set. So this changeset adds the global entry point instructions, sets the metadata so the system linker knows where the local entry point is, inserts code to save the TOC pointer at 24(r1), adds a nop after any call not known to be local and copes with the odd non-local code transfer in the runtime (e.g. the stuff around jmpdefer). It does not actually compile PIC yet. Change-Id: I7522e22bdfd2f891745a900c60254fe9e372c854 Reviewed-on: https://go-review.googlesource.com/15967 Reviewed-by: Russ Cox <rsc@golang.org>
2015-10-15 20:42:09 -06:00
// 2. sub 8 bytes to get back to either nop or toc reload before deferreturn
// 3. BR to fn
cmd/compile, cmd/link, runtime: on ppc64x, maintain the TOC pointer in R2 when compiling PIC The PowerPC ISA does not have a PC-relative load instruction, which poses obvious challenges when generating position-independent code. The way the ELFv2 ABI addresses this is to specify that r2 points to a per "module" (shared library or executable) TOC pointer. Maintaining this pointer requires cooperation between codegen and the system linker: * Non-leaf functions leave space on the stack at r1+24 to save the TOC pointer. * A call to a function that *might* have to go via a PLT stub must be followed by a nop instruction that the system linker can replace with "ld r1, 24(r1)" to restore the TOC pointer (only when dynamically linking Go code). * When calling a function via a function pointer, the address of the function must be in r12, and the first couple of instructions (the "global entry point") of the called function use this to derive the address of the TOC for the module it is in. * When calling a function that is implemented in the same module, the system linker adjusts the call to skip over the instructions mentioned above (the "local entry point"), assuming that r2 is already correctly set. So this changeset adds the global entry point instructions, sets the metadata so the system linker knows where the local entry point is, inserts code to save the TOC pointer at 24(r1), adds a nop after any call not known to be local and copes with the odd non-local code transfer in the runtime (e.g. the stuff around jmpdefer). It does not actually compile PIC yet. Change-Id: I7522e22bdfd2f891745a900c60254fe9e372c854 Reviewed-on: https://go-review.googlesource.com/15967 Reviewed-by: Russ Cox <rsc@golang.org>
2015-10-15 20:42:09 -06:00
// When dynamically linking Go, it is not sufficient to rewind to the BL
// deferreturn -- we might be jumping between modules and so we need to reset
// the TOC pointer in r2. To do this, codegen inserts MOVD 24(R1), R2 *before*
// the BL deferreturn and jmpdefer rewinds to that.
TEXT runtime·jmpdefer(SB), NOSPLIT|NOFRAME, $0-16
MOVD 0(R1), R31
cmd/compile, cmd/link, runtime: on ppc64x, maintain the TOC pointer in R2 when compiling PIC The PowerPC ISA does not have a PC-relative load instruction, which poses obvious challenges when generating position-independent code. The way the ELFv2 ABI addresses this is to specify that r2 points to a per "module" (shared library or executable) TOC pointer. Maintaining this pointer requires cooperation between codegen and the system linker: * Non-leaf functions leave space on the stack at r1+24 to save the TOC pointer. * A call to a function that *might* have to go via a PLT stub must be followed by a nop instruction that the system linker can replace with "ld r1, 24(r1)" to restore the TOC pointer (only when dynamically linking Go code). * When calling a function via a function pointer, the address of the function must be in r12, and the first couple of instructions (the "global entry point") of the called function use this to derive the address of the TOC for the module it is in. * When calling a function that is implemented in the same module, the system linker adjusts the call to skip over the instructions mentioned above (the "local entry point"), assuming that r2 is already correctly set. So this changeset adds the global entry point instructions, sets the metadata so the system linker knows where the local entry point is, inserts code to save the TOC pointer at 24(r1), adds a nop after any call not known to be local and copes with the odd non-local code transfer in the runtime (e.g. the stuff around jmpdefer). It does not actually compile PIC yet. Change-Id: I7522e22bdfd2f891745a900c60254fe9e372c854 Reviewed-on: https://go-review.googlesource.com/15967 Reviewed-by: Russ Cox <rsc@golang.org>
2015-10-15 20:42:09 -06:00
SUB $8, R31
MOVD R31, LR
MOVD fv+0(FP), R11
MOVD argp+8(FP), R1
SUB $FIXED_FRAME, R1
MOVD 0(R11), R12
MOVD R12, CTR
BR (CTR)
// Save state of caller into g->sched. Smashes R31.
TEXT gosave<>(SB),NOSPLIT|NOFRAME,$0
MOVD LR, R31
MOVD R31, (g_sched+gobuf_pc)(g)
MOVD R1, (g_sched+gobuf_sp)(g)
MOVD R0, (g_sched+gobuf_lr)(g)
MOVD R0, (g_sched+gobuf_ret)(g)
MOVD R0, (g_sched+gobuf_ctxt)(g)
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
MOVD fn+0(FP), R3
MOVD arg+8(FP), R4
MOVD R1, R7 // save original stack pointer
MOVD g, R5
// Figure out if we need to switch to m->g0 stack.
// We get called to create new OS threads too, and those
// come in on the m->g0 stack already.
MOVD g_m(g), R6
MOVD m_g0(R6), R6
CMP R6, g
BEQ g0
BL gosave<>(SB)
MOVD R6, g
BL runtime·save_g(SB)
MOVD (g_sched+gobuf_sp)(g), R1
// Now on a scheduling stack (a pthread-created stack).
g0:
// Save room for two of our pointers, plus 32 bytes of callee
// save area that lives on the caller stack.
SUB $48, R1
RLDCR $0, R1, $~15, R1 // 16-byte alignment for gcc ABI
MOVD R5, 40(R1) // save old g on stack
MOVD (g_stack+stack_hi)(R5), R5
SUB R7, R5
MOVD R5, 32(R1) // save depth in old g stack (can't just save SP, as stack might be copied during a callback)
MOVD R0, 0(R1) // clear back chain pointer (TODO can we give it real back trace information?)
// This is a "global call", so put the global entry point in r12
MOVD R3, R12
MOVD R12, CTR
MOVD R4, R3 // arg in r3
BL (CTR)
// C code can clobber R0, so set it back to 0. F27-F31 are
// callee save, so we don't need to recover those.
XOR R0, R0
cmd/compile, cmd/link, runtime: on ppc64x, maintain the TOC pointer in R2 when compiling PIC The PowerPC ISA does not have a PC-relative load instruction, which poses obvious challenges when generating position-independent code. The way the ELFv2 ABI addresses this is to specify that r2 points to a per "module" (shared library or executable) TOC pointer. Maintaining this pointer requires cooperation between codegen and the system linker: * Non-leaf functions leave space on the stack at r1+24 to save the TOC pointer. * A call to a function that *might* have to go via a PLT stub must be followed by a nop instruction that the system linker can replace with "ld r1, 24(r1)" to restore the TOC pointer (only when dynamically linking Go code). * When calling a function via a function pointer, the address of the function must be in r12, and the first couple of instructions (the "global entry point") of the called function use this to derive the address of the TOC for the module it is in. * When calling a function that is implemented in the same module, the system linker adjusts the call to skip over the instructions mentioned above (the "local entry point"), assuming that r2 is already correctly set. So this changeset adds the global entry point instructions, sets the metadata so the system linker knows where the local entry point is, inserts code to save the TOC pointer at 24(r1), adds a nop after any call not known to be local and copes with the odd non-local code transfer in the runtime (e.g. the stuff around jmpdefer). It does not actually compile PIC yet. Change-Id: I7522e22bdfd2f891745a900c60254fe9e372c854 Reviewed-on: https://go-review.googlesource.com/15967 Reviewed-by: Russ Cox <rsc@golang.org>
2015-10-15 20:42:09 -06:00
// Restore g, stack pointer, toc pointer.
// R3 is errno, so don't touch it
MOVD 40(R1), g
cmd/compile, cmd/link, runtime: on ppc64x, maintain the TOC pointer in R2 when compiling PIC The PowerPC ISA does not have a PC-relative load instruction, which poses obvious challenges when generating position-independent code. The way the ELFv2 ABI addresses this is to specify that r2 points to a per "module" (shared library or executable) TOC pointer. Maintaining this pointer requires cooperation between codegen and the system linker: * Non-leaf functions leave space on the stack at r1+24 to save the TOC pointer. * A call to a function that *might* have to go via a PLT stub must be followed by a nop instruction that the system linker can replace with "ld r1, 24(r1)" to restore the TOC pointer (only when dynamically linking Go code). * When calling a function via a function pointer, the address of the function must be in r12, and the first couple of instructions (the "global entry point") of the called function use this to derive the address of the TOC for the module it is in. * When calling a function that is implemented in the same module, the system linker adjusts the call to skip over the instructions mentioned above (the "local entry point"), assuming that r2 is already correctly set. So this changeset adds the global entry point instructions, sets the metadata so the system linker knows where the local entry point is, inserts code to save the TOC pointer at 24(r1), adds a nop after any call not known to be local and copes with the odd non-local code transfer in the runtime (e.g. the stuff around jmpdefer). It does not actually compile PIC yet. Change-Id: I7522e22bdfd2f891745a900c60254fe9e372c854 Reviewed-on: https://go-review.googlesource.com/15967 Reviewed-by: Russ Cox <rsc@golang.org>
2015-10-15 20:42:09 -06:00
MOVD (g_stack+stack_hi)(g), R5
MOVD 32(R1), R6
SUB R6, R5
MOVD 24(R5), R2
BL runtime·save_g(SB)
MOVD (g_stack+stack_hi)(g), R5
MOVD 32(R1), R6
SUB R6, R5
MOVD R5, R1
MOVW R3, ret+16(FP)
RET
// 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
MOVD $fn+0(FP), R3
MOVD R3, FIXED_FRAME+0(R1)
MOVD frame+8(FP), R3
MOVD R3, FIXED_FRAME+8(R1)
MOVD framesize+16(FP), R3
MOVD R3, FIXED_FRAME+16(R1)
MOVD $runtime·cgocallback_gofunc(SB), R12
MOVD R12, CTR
BL (CTR)
RET
// cgocallback_gofunc(FuncVal*, void *frame, uintptr framesize)
// See cgocall.go for more details.
TEXT ·cgocallback_gofunc(SB),NOSPLIT,$16-24
NO_LOCAL_POINTERS
// Load m and g from thread-local storage.
MOVB runtime·iscgo(SB), R3
CMP R3, $0
BEQ nocgo
BL runtime·load_g(SB)
nocgo:
// If g is nil, Go did not create the current thread.
// Call needm to obtain one 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.
CMP g, $0
BNE havem
MOVD g, savedm-8(SP) // g is zero, so is m.
MOVD $runtime·needm(SB), R12
MOVD R12, CTR
BL (CTR)
// 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
// 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.
MOVD g_m(g), R3
MOVD m_g0(R3), R3
MOVD R1, (g_sched+gobuf_sp)(R3)
havem:
MOVD g_m(g), R8
MOVD R8, savedm-8(SP)
// 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 8(R1) aka savedsp-16(SP).
MOVD m_g0(R8), R3
MOVD (g_sched+gobuf_sp)(R3), R4
MOVD R4, savedsp-16(SP)
MOVD R1, (g_sched+gobuf_sp)(R3)
// 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.
// 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)
// so that the traceback will seamlessly trace back into
// the earlier calls.
//
// In the new goroutine, -16(SP) and -8(SP) are unused.
MOVD m_curg(R8), g
BL runtime·save_g(SB)
MOVD (g_sched+gobuf_sp)(g), R4 // prepare stack as R4
MOVD (g_sched+gobuf_pc)(g), R5
MOVD R5, -(FIXED_FRAME+16)(R4)
MOVD $-(FIXED_FRAME+16)(R4), R1
BL runtime·cgocallbackg(SB)
// Restore g->sched (== m->curg->sched) from saved values.
MOVD 0(R1), R5
MOVD R5, (g_sched+gobuf_pc)(g)
MOVD $(FIXED_FRAME+16)(R1), R4
MOVD R4, (g_sched+gobuf_sp)(g)
// 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.)
MOVD g_m(g), R8
MOVD m_g0(R8), g
BL runtime·save_g(SB)
MOVD (g_sched+gobuf_sp)(g), R1
MOVD savedsp-16(SP), R4
MOVD R4, (g_sched+gobuf_sp)(g)
// 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.
MOVD savedm-8(SP), R6
CMP R6, $0
BNE droppedm
MOVD $runtime·dropm(SB), R12
MOVD R12, CTR
BL (CTR)
droppedm:
// Done!
RET
// void setg(G*); set g. for use by needm.
TEXT runtime·setg(SB), NOSPLIT, $0-8
MOVD gg+0(FP), g
// This only happens if iscgo, so jump straight to save_g
BL runtime·save_g(SB)
RET
// void setg_gcc(G*); set g in C TLS.
// Must obey the gcc calling convention.
TEXT setg_gcc<>(SB),NOSPLIT|NOFRAME,$0-0
// The standard prologue clobbers R31, which is callee-save in
// the C ABI, so we have to use $-8-0 and save LR ourselves.
MOVD LR, R4
// Also save g and R31, since they're callee-save in C ABI
MOVD R31, R5
MOVD g, R6
MOVD R3, g
BL runtime·save_g(SB)
MOVD R6, g
MOVD R5, R31
MOVD R4, LR
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
MOVD FIXED_FRAME+8(R1), R3 // LR saved by caller
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
MOVD runtime·stackBarrierPC(SB), R4
CMP R3, R4
BNE nobar
// Get original return PC.
BL runtime·nextBarrierPC(SB)
MOVD FIXED_FRAME+0(R1), R3
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
nobar:
MOVD R3, 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
MOVD pc+8(FP), R3
MOVD FIXED_FRAME+8(R1), R4
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
MOVD runtime·stackBarrierPC(SB), R5
CMP R4, R5
BEQ setbar
MOVD R3, FIXED_FRAME+8(R1) // set LR in caller
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.
MOVD R3, FIXED_FRAME+0(R1)
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
BL runtime·setNextBarrierPC(SB)
RET
TEXT runtime·getcallersp(SB),NOSPLIT,$0-16
MOVD argp+0(FP), R3
SUB $FIXED_FRAME, R3
MOVD R3, ret+8(FP)
RET
TEXT runtime·abort(SB),NOSPLIT|NOFRAME,$0-0
MOVW (R0), R0
UNDEF
#define TBRL 268
#define TBRU 269 /* Time base Upper/Lower */
// int64 runtime·cputicks(void)
TEXT runtime·cputicks(SB),NOSPLIT,$0-8
MOVW SPR(TBRU), R4
MOVW SPR(TBRL), R3
MOVW SPR(TBRU), R5
CMPW R4, R5
BNE -4(PC)
SLD $32, R5
OR R5, R3
MOVD R3, 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,$40-24
GO_ARGS
NO_LOCAL_POINTERS
MOVD p+0(FP), R3
MOVD h+8(FP), R4
MOVD 8(R11), R5
MOVD R3, FIXED_FRAME+0(R1)
MOVD R4, FIXED_FRAME+8(R1)
MOVD R5, FIXED_FRAME+16(R1)
BL runtime·memhash(SB)
MOVD FIXED_FRAME+24(R1), R3
MOVD R3, ret+16(FP)
RET
// AES hashing not implemented for ppc64
TEXT runtime·aeshash(SB),NOSPLIT|NOFRAME,$0-0
MOVW (R0), R1
TEXT runtime·aeshash32(SB),NOSPLIT|NOFRAME,$0-0
MOVW (R0), R1
TEXT runtime·aeshash64(SB),NOSPLIT|NOFRAME,$0-0
MOVW (R0), R1
TEXT runtime·aeshashstr(SB),NOSPLIT|NOFRAME,$0-0
MOVW (R0), R1
TEXT runtime·memeq(SB),NOSPLIT|NOFRAME,$0-25
MOVD a+0(FP), R3
MOVD b+8(FP), R4
MOVD size+16(FP), R5
SUB $1, R3
SUB $1, R4
ADD R3, R5, R8
loop:
CMP R3, R8
BNE test
MOVD $1, R3
MOVB R3, ret+24(FP)
RET
test:
MOVBZU 1(R3), R6
MOVBZU 1(R4), R7
CMP R6, R7
BEQ loop
MOVB R0, ret+24(FP)
RET
// memequal_varlen(a, b unsafe.Pointer) bool
TEXT runtime·memequal_varlen(SB),NOSPLIT,$40-17
MOVD a+0(FP), R3
MOVD b+8(FP), R4
CMP R3, R4
BEQ eq
MOVD 8(R11), R5 // compiler stores size at offset 8 in the closure
MOVD R3, FIXED_FRAME+0(R1)
MOVD R4, FIXED_FRAME+8(R1)
MOVD R5, FIXED_FRAME+16(R1)
BL runtime·memeq(SB)
MOVBZ FIXED_FRAME+24(R1), R3
MOVB R3, ret+16(FP)
RET
eq:
MOVD $1, R3
MOVB R3, 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
MOVD s1str+0(FP), R3
MOVD s2str+16(FP), R4
MOVD $1, R5
MOVB R5, ret+32(FP)
CMP R3, R4
BNE 2(PC)
RET
MOVD s1len+8(FP), R5
SUB $1, R3
SUB $1, R4
ADD R3, R5, R8
loop:
CMP R3, R8
BNE 2(PC)
RET
MOVBZU 1(R3), R6
MOVBZU 1(R4), R7
CMP R6, R7
BEQ loop
MOVB R0, ret+32(FP)
RET
// TODO: share code with memeq?
TEXT bytes·Equal(SB),NOSPLIT,$0-49
MOVD a_len+8(FP), R3
MOVD b_len+32(FP), R4
CMP R3, R4 // unequal lengths are not equal
BNE noteq
MOVD a+0(FP), R5
MOVD b+24(FP), R6
SUB $1, R5
SUB $1, R6
ADD R5, R3 // end-1
loop:
CMP R5, R3
BEQ equal // reached the end
MOVBZU 1(R5), R4
MOVBZU 1(R6), R7
CMP R4, R7
BEQ loop
noteq:
MOVBZ R0, ret+48(FP)
RET
equal:
MOVD $1, R3
MOVBZ R3, ret+48(FP)
RET
TEXT bytes·IndexByte(SB),NOSPLIT,$0-40
MOVD s+0(FP), R3
MOVD s_len+8(FP), R4
MOVBZ c+24(FP), R5 // byte to find
MOVD R3, R6 // store base for later
SUB $1, R3
ADD R3, R4 // end-1
loop:
CMP R3, R4
BEQ notfound
MOVBZU 1(R3), R7
CMP R7, R5
BNE loop
SUB R6, R3 // remove base
MOVD R3, ret+32(FP)
RET
notfound:
MOVD $-1, R3
MOVD R3, ret+32(FP)
RET
TEXT strings·IndexByte(SB),NOSPLIT,$0-32
MOVD p+0(FP), R3
MOVD b_len+8(FP), R4
MOVBZ c+16(FP), R5 // byte to find
MOVD R3, R6 // store base for later
SUB $1, R3
ADD R3, R4 // end-1
loop:
CMP R3, R4
BEQ notfound
MOVBZU 1(R3), R7
CMP R7, R5
BNE loop
SUB R6, R3 // remove base
MOVD R3, ret+24(FP)
RET
notfound:
MOVD $-1, R3
MOVD R3, ret+24(FP)
RET
TEXT runtime·cmpstring(SB),NOSPLIT|NOFRAME,$0-40
MOVD s1_base+0(FP), R5
MOVD s1_len+8(FP), R3
MOVD s2_base+16(FP), R6
MOVD s2_len+24(FP), R4
MOVD $ret+32(FP), R7
BR runtime·cmpbody<>(SB)
TEXT bytes·Compare(SB),NOSPLIT|NOFRAME,$0-56
MOVD s1+0(FP), R5
MOVD s1+8(FP), R3
MOVD s2+24(FP), R6
MOVD s2+32(FP), R4
MOVD $ret+48(FP), R7
BR runtime·cmpbody<>(SB)
// On entry:
// R3 is the length of s1
// R4 is the length of s2
// R5 points to the start of s1
// R6 points to the start of s2
// R7 points to return value (-1/0/1 will be written here)
//
// On exit:
// R5, R6, R8, R9 and R10 are clobbered
TEXT runtime·cmpbody<>(SB),NOSPLIT|NOFRAME,$0-0
CMP R5, R6
BEQ samebytes // same starting pointers; compare lengths
SUB $1, R5
SUB $1, R6
MOVD R4, R8
CMP R3, R4
BGE 2(PC)
MOVD R3, R8 // R8 is min(R3, R4)
ADD R5, R8 // R5 is current byte in s1, R8 is last byte in s1 to compare
loop:
CMP R5, R8
BEQ samebytes // all compared bytes were the same; compare lengths
MOVBZU 1(R5), R9
MOVBZU 1(R6), R10
CMP R9, R10
BEQ loop
// bytes differed
MOVD $1, R4
BGT 2(PC)
NEG R4
MOVD R4, (R7)
RET
samebytes:
MOVD $1, R8
CMP R3, R4
BNE 3(PC)
MOVD R0, (R7)
RET
BGT 2(PC)
NEG R8
MOVD R8, (R7)
RET
TEXT runtime·fastrand1(SB), NOSPLIT, $0-4
MOVD g_m(g), R4
MOVWZ m_fastrand(R4), R3
ADD R3, R3
CMPW R3, $0
BGE 2(PC)
XOR $0x88888eef, R3
MOVW R3, m_fastrand(R4)
MOVW R3, ret+0(FP)
RET
TEXT runtime·return0(SB), NOSPLIT, $0
MOVW $0, R3
RET
// Called from cgo wrappers, this function returns g->m->curg.stack.hi.
// Must obey the gcc calling convention.
TEXT _cgo_topofstack(SB),NOSPLIT|NOFRAME,$0
// g (R30) and R31 are callee-save in the C ABI, so save them
MOVD g, R4
MOVD R31, R5
MOVD LR, R6
BL runtime·load_g(SB) // clobbers g (R30), R31
MOVD g_m(g), R3
MOVD m_curg(R3), R3
MOVD (g_stack+stack_hi)(R3), R3
MOVD R4, g
MOVD R5, R31
MOVD R6, LR
RET
// The top-most function running on a goroutine
// returns to goexit+PCQuantum.
cmd/compile, cmd/link, runtime: on ppc64x, maintain the TOC pointer in R2 when compiling PIC The PowerPC ISA does not have a PC-relative load instruction, which poses obvious challenges when generating position-independent code. The way the ELFv2 ABI addresses this is to specify that r2 points to a per "module" (shared library or executable) TOC pointer. Maintaining this pointer requires cooperation between codegen and the system linker: * Non-leaf functions leave space on the stack at r1+24 to save the TOC pointer. * A call to a function that *might* have to go via a PLT stub must be followed by a nop instruction that the system linker can replace with "ld r1, 24(r1)" to restore the TOC pointer (only when dynamically linking Go code). * When calling a function via a function pointer, the address of the function must be in r12, and the first couple of instructions (the "global entry point") of the called function use this to derive the address of the TOC for the module it is in. * When calling a function that is implemented in the same module, the system linker adjusts the call to skip over the instructions mentioned above (the "local entry point"), assuming that r2 is already correctly set. So this changeset adds the global entry point instructions, sets the metadata so the system linker knows where the local entry point is, inserts code to save the TOC pointer at 24(r1), adds a nop after any call not known to be local and copes with the odd non-local code transfer in the runtime (e.g. the stuff around jmpdefer). It does not actually compile PIC yet. Change-Id: I7522e22bdfd2f891745a900c60254fe9e372c854 Reviewed-on: https://go-review.googlesource.com/15967 Reviewed-by: Russ Cox <rsc@golang.org>
2015-10-15 20:42:09 -06:00
//
// When dynamically linking Go, it can be returned to from a function
// implemented in a different module and so needs to reload the TOC pointer
// from the stack (although this function declares that it does not set up x-a
// frame, newproc1 does in fact allocate one for goexit and saves the TOC
// pointer in the correct place).
// goexit+_PCQuantum is halfway through the usual global entry point prologue
// that derives r2 from r12 which is a bit silly, but not harmful.
TEXT runtime·goexit(SB),NOSPLIT|NOFRAME,$0-0
cmd/compile, cmd/link, runtime: on ppc64x, maintain the TOC pointer in R2 when compiling PIC The PowerPC ISA does not have a PC-relative load instruction, which poses obvious challenges when generating position-independent code. The way the ELFv2 ABI addresses this is to specify that r2 points to a per "module" (shared library or executable) TOC pointer. Maintaining this pointer requires cooperation between codegen and the system linker: * Non-leaf functions leave space on the stack at r1+24 to save the TOC pointer. * A call to a function that *might* have to go via a PLT stub must be followed by a nop instruction that the system linker can replace with "ld r1, 24(r1)" to restore the TOC pointer (only when dynamically linking Go code). * When calling a function via a function pointer, the address of the function must be in r12, and the first couple of instructions (the "global entry point") of the called function use this to derive the address of the TOC for the module it is in. * When calling a function that is implemented in the same module, the system linker adjusts the call to skip over the instructions mentioned above (the "local entry point"), assuming that r2 is already correctly set. So this changeset adds the global entry point instructions, sets the metadata so the system linker knows where the local entry point is, inserts code to save the TOC pointer at 24(r1), adds a nop after any call not known to be local and copes with the odd non-local code transfer in the runtime (e.g. the stuff around jmpdefer). It does not actually compile PIC yet. Change-Id: I7522e22bdfd2f891745a900c60254fe9e372c854 Reviewed-on: https://go-review.googlesource.com/15967 Reviewed-by: Russ Cox <rsc@golang.org>
2015-10-15 20:42:09 -06:00
MOVD 24(R1), R2
BL runtime·goexit1(SB) // does not return
// traceback from goexit1 must hit code range of goexit
MOVD R0, R0 // NOP
TEXT runtime·prefetcht0(SB),NOSPLIT,$0-8
RET
TEXT runtime·prefetcht1(SB),NOSPLIT,$0-8
RET
TEXT runtime·prefetcht2(SB),NOSPLIT,$0-8
RET
TEXT runtime·prefetchnta(SB),NOSPLIT,$0-8
RET
TEXT runtime·sigreturn(SB),NOSPLIT,$0-8
RET
cmd/compile, cmd/link, runtime: on ppc64x, maintain the TOC pointer in R2 when compiling PIC The PowerPC ISA does not have a PC-relative load instruction, which poses obvious challenges when generating position-independent code. The way the ELFv2 ABI addresses this is to specify that r2 points to a per "module" (shared library or executable) TOC pointer. Maintaining this pointer requires cooperation between codegen and the system linker: * Non-leaf functions leave space on the stack at r1+24 to save the TOC pointer. * A call to a function that *might* have to go via a PLT stub must be followed by a nop instruction that the system linker can replace with "ld r1, 24(r1)" to restore the TOC pointer (only when dynamically linking Go code). * When calling a function via a function pointer, the address of the function must be in r12, and the first couple of instructions (the "global entry point") of the called function use this to derive the address of the TOC for the module it is in. * When calling a function that is implemented in the same module, the system linker adjusts the call to skip over the instructions mentioned above (the "local entry point"), assuming that r2 is already correctly set. So this changeset adds the global entry point instructions, sets the metadata so the system linker knows where the local entry point is, inserts code to save the TOC pointer at 24(r1), adds a nop after any call not known to be local and copes with the odd non-local code transfer in the runtime (e.g. the stuff around jmpdefer). It does not actually compile PIC yet. Change-Id: I7522e22bdfd2f891745a900c60254fe9e372c854 Reviewed-on: https://go-review.googlesource.com/15967 Reviewed-by: Russ Cox <rsc@golang.org>
2015-10-15 20:42:09 -06:00
// prepGoExitFrame saves the current TOC pointer (i.e. the TOC pointer for the
// module containing runtime) to the frame that goexit will execute in when
// the goroutine exits. It's implemented in assembly mainly because that's the
// easiest way to get access to R2.
TEXT runtime·prepGoExitFrame(SB),NOSPLIT,$0-8
MOVD sp+0(FP), R3
MOVD R2, 24(R3)
RET
TEXT runtime·addmoduledata(SB),NOSPLIT|NOFRAME,$0-0
ADD $-8, R1
MOVD R31, 0(R1)
MOVD runtime·lastmoduledatap(SB), R4
MOVD R3, moduledata_next(R4)
MOVD R3, runtime·lastmoduledatap(SB)
MOVD 0(R1), R31
ADD $8, R1
RET
TEXT ·checkASM(SB),NOSPLIT,$0-1
MOVW $1, R3
MOVB R3, ret+0(FP)
RET