From 4a7ed1fab766a7a908e2cb20294e43b43ce7cf6c Mon Sep 17 00:00:00 2001 From: Cherry Zhang Date: Fri, 25 Oct 2019 00:51:10 -0400 Subject: [PATCH] cmd/compile: mark architecture-specific unsafe points Introduce a mechanism for marking architecture-specific Ops unsafe. And mark ones that use REGTMP on ARM64, as for async preemption we will be using REGTMP as a temporary register in the injected call. Change-Id: I8ff22e87d8f9cb10d02a2f0af7c12ad6d7d58f54 Reviewed-on: https://go-review.googlesource.com/c/go/+/203459 Run-TryBot: Cherry Zhang Reviewed-by: Austin Clements --- src/cmd/compile/internal/gc/plive.go | 9 +++++++++ src/cmd/compile/internal/ssa/gen/ARM64Ops.go | 16 ++++++++-------- src/cmd/compile/internal/ssa/gen/main.go | 5 +++++ src/cmd/compile/internal/ssa/op.go | 1 + src/cmd/compile/internal/ssa/opGen.go | 9 +++++++++ 5 files changed, 32 insertions(+), 8 deletions(-) diff --git a/src/cmd/compile/internal/gc/plive.go b/src/cmd/compile/internal/gc/plive.go index 5f0ece0ad7..d6ce9017e4 100644 --- a/src/cmd/compile/internal/gc/plive.go +++ b/src/cmd/compile/internal/gc/plive.go @@ -639,6 +639,15 @@ func (lv *Liveness) markUnsafePoints() { lv.unsafePoints = bvalloc(int32(lv.f.NumValues())) + // Mark architecture-specific unsafe pointes. + for _, b := range lv.f.Blocks { + for _, v := range b.Values { + if v.Op.UnsafePoint() { + lv.unsafePoints.Set(int32(v.ID)) + } + } + } + // Mark write barrier unsafe points. for _, wbBlock := range lv.f.WBLoads { if wbBlock.Kind == ssa.BlockPlain && len(wbBlock.Values) == 0 { diff --git a/src/cmd/compile/internal/ssa/gen/ARM64Ops.go b/src/cmd/compile/internal/ssa/gen/ARM64Ops.go index 59a6004b97..6fdb5729c5 100644 --- a/src/cmd/compile/internal/ssa/gen/ARM64Ops.go +++ b/src/cmd/compile/internal/ssa/gen/ARM64Ops.go @@ -620,8 +620,8 @@ func init() { // LDAXR (Rarg0), Rout // STLXR Rarg1, (Rarg0), Rtmp // CBNZ Rtmp, -2(PC) - {name: "LoweredAtomicExchange64", argLength: 3, reg: gpxchg, resultNotInArgs: true, faultOnNilArg0: true, hasSideEffects: true}, - {name: "LoweredAtomicExchange32", argLength: 3, reg: gpxchg, resultNotInArgs: true, faultOnNilArg0: true, hasSideEffects: true}, + {name: "LoweredAtomicExchange64", argLength: 3, reg: gpxchg, resultNotInArgs: true, faultOnNilArg0: true, hasSideEffects: true, unsafePoint: true}, + {name: "LoweredAtomicExchange32", argLength: 3, reg: gpxchg, resultNotInArgs: true, faultOnNilArg0: true, hasSideEffects: true, unsafePoint: true}, // atomic add. // *arg0 += arg1. arg2=mem. returns . auxint must be zero. @@ -629,8 +629,8 @@ func init() { // ADD Rarg1, Rout // STLXR Rout, (Rarg0), Rtmp // CBNZ Rtmp, -3(PC) - {name: "LoweredAtomicAdd64", argLength: 3, reg: gpxchg, resultNotInArgs: true, faultOnNilArg0: true, hasSideEffects: true}, - {name: "LoweredAtomicAdd32", argLength: 3, reg: gpxchg, resultNotInArgs: true, faultOnNilArg0: true, hasSideEffects: true}, + {name: "LoweredAtomicAdd64", argLength: 3, reg: gpxchg, resultNotInArgs: true, faultOnNilArg0: true, hasSideEffects: true, unsafePoint: true}, + {name: "LoweredAtomicAdd32", argLength: 3, reg: gpxchg, resultNotInArgs: true, faultOnNilArg0: true, hasSideEffects: true, unsafePoint: true}, // atomic add variant. // *arg0 += arg1. arg2=mem. returns . auxint must be zero. @@ -653,8 +653,8 @@ func init() { // STLXR Rarg2, (Rarg0), Rtmp // CBNZ Rtmp, -4(PC) // CSET EQ, Rout - {name: "LoweredAtomicCas64", argLength: 4, reg: gpcas, resultNotInArgs: true, clobberFlags: true, faultOnNilArg0: true, hasSideEffects: true}, - {name: "LoweredAtomicCas32", argLength: 4, reg: gpcas, resultNotInArgs: true, clobberFlags: true, faultOnNilArg0: true, hasSideEffects: true}, + {name: "LoweredAtomicCas64", argLength: 4, reg: gpcas, resultNotInArgs: true, clobberFlags: true, faultOnNilArg0: true, hasSideEffects: true, unsafePoint: true}, + {name: "LoweredAtomicCas32", argLength: 4, reg: gpcas, resultNotInArgs: true, clobberFlags: true, faultOnNilArg0: true, hasSideEffects: true, unsafePoint: true}, // atomic and/or. // *arg0 &= (|=) arg1. arg2=mem. returns . auxint must be zero. @@ -662,8 +662,8 @@ func init() { // AND/OR Rarg1, Rout // STLXRB Rout, (Rarg0), Rtmp // CBNZ Rtmp, -3(PC) - {name: "LoweredAtomicAnd8", argLength: 3, reg: gpxchg, resultNotInArgs: true, asm: "AND", typ: "(UInt8,Mem)", faultOnNilArg0: true, hasSideEffects: true}, - {name: "LoweredAtomicOr8", argLength: 3, reg: gpxchg, resultNotInArgs: true, asm: "ORR", typ: "(UInt8,Mem)", faultOnNilArg0: true, hasSideEffects: true}, + {name: "LoweredAtomicAnd8", argLength: 3, reg: gpxchg, resultNotInArgs: true, asm: "AND", typ: "(UInt8,Mem)", faultOnNilArg0: true, hasSideEffects: true, unsafePoint: true}, + {name: "LoweredAtomicOr8", argLength: 3, reg: gpxchg, resultNotInArgs: true, asm: "ORR", typ: "(UInt8,Mem)", faultOnNilArg0: true, hasSideEffects: true, unsafePoint: true}, // LoweredWB invokes runtime.gcWriteBarrier. arg0=destptr, arg1=srcptr, arg2=mem, aux=runtime.gcWriteBarrier // It saves all GP registers if necessary, diff --git a/src/cmd/compile/internal/ssa/gen/main.go b/src/cmd/compile/internal/ssa/gen/main.go index 55ba338efa..2107da4f4e 100644 --- a/src/cmd/compile/internal/ssa/gen/main.go +++ b/src/cmd/compile/internal/ssa/gen/main.go @@ -63,6 +63,7 @@ type opData struct { usesScratch bool // this op requires scratch memory space hasSideEffects bool // for "reasons", not to be eliminated. E.g., atomic store, #19182. zeroWidth bool // op never translates into any machine code. example: copy, which may sometimes translate to machine code, is not zero-width. + unsafePoint bool // this op is an unsafe point, i.e. not safe for async preemption symEffect string // effect this op has on symbol in aux scale uint8 // amd64/386 indexed load scale } @@ -325,6 +326,9 @@ func genOp() { if v.zeroWidth { fmt.Fprintln(w, "zeroWidth: true,") } + if v.unsafePoint { + fmt.Fprintln(w, "unsafePoint: true,") + } needEffect := strings.HasPrefix(v.aux, "Sym") if v.symEffect != "" { if !needEffect { @@ -401,6 +405,7 @@ func genOp() { fmt.Fprintln(w, "func (o Op) SymEffect() SymEffect { return opcodeTable[o].symEffect }") fmt.Fprintln(w, "func (o Op) IsCall() bool { return opcodeTable[o].call }") + fmt.Fprintln(w, "func (o Op) UnsafePoint() bool { return opcodeTable[o].unsafePoint }") // generate registers for _, a := range archs { diff --git a/src/cmd/compile/internal/ssa/op.go b/src/cmd/compile/internal/ssa/op.go index 10534433a7..ec9e7863a0 100644 --- a/src/cmd/compile/internal/ssa/op.go +++ b/src/cmd/compile/internal/ssa/op.go @@ -36,6 +36,7 @@ type opInfo struct { usesScratch bool // this op requires scratch memory space hasSideEffects bool // for "reasons", not to be eliminated. E.g., atomic store, #19182. zeroWidth bool // op never translates into any machine code. example: copy, which may sometimes translate to machine code, is not zero-width. + unsafePoint bool // this op is an unsafe point, i.e. not safe for async preemption symEffect SymEffect // effect this op has on symbol in aux scale uint8 // amd64/386 indexed load scale } diff --git a/src/cmd/compile/internal/ssa/opGen.go b/src/cmd/compile/internal/ssa/opGen.go index 9f112c10f1..e9a709467e 100644 --- a/src/cmd/compile/internal/ssa/opGen.go +++ b/src/cmd/compile/internal/ssa/opGen.go @@ -18948,6 +18948,7 @@ var opcodeTable = [...]opInfo{ resultNotInArgs: true, faultOnNilArg0: true, hasSideEffects: true, + unsafePoint: true, reg: regInfo{ inputs: []inputInfo{ {1, 805044223}, // R0 R1 R2 R3 R4 R5 R6 R7 R8 R9 R10 R11 R12 R13 R14 R15 R16 R17 R19 R20 R21 R22 R23 R24 R25 R26 g R30 @@ -18964,6 +18965,7 @@ var opcodeTable = [...]opInfo{ resultNotInArgs: true, faultOnNilArg0: true, hasSideEffects: true, + unsafePoint: true, reg: regInfo{ inputs: []inputInfo{ {1, 805044223}, // R0 R1 R2 R3 R4 R5 R6 R7 R8 R9 R10 R11 R12 R13 R14 R15 R16 R17 R19 R20 R21 R22 R23 R24 R25 R26 g R30 @@ -18980,6 +18982,7 @@ var opcodeTable = [...]opInfo{ resultNotInArgs: true, faultOnNilArg0: true, hasSideEffects: true, + unsafePoint: true, reg: regInfo{ inputs: []inputInfo{ {1, 805044223}, // R0 R1 R2 R3 R4 R5 R6 R7 R8 R9 R10 R11 R12 R13 R14 R15 R16 R17 R19 R20 R21 R22 R23 R24 R25 R26 g R30 @@ -18996,6 +18999,7 @@ var opcodeTable = [...]opInfo{ resultNotInArgs: true, faultOnNilArg0: true, hasSideEffects: true, + unsafePoint: true, reg: regInfo{ inputs: []inputInfo{ {1, 805044223}, // R0 R1 R2 R3 R4 R5 R6 R7 R8 R9 R10 R11 R12 R13 R14 R15 R16 R17 R19 R20 R21 R22 R23 R24 R25 R26 g R30 @@ -19045,6 +19049,7 @@ var opcodeTable = [...]opInfo{ clobberFlags: true, faultOnNilArg0: true, hasSideEffects: true, + unsafePoint: true, reg: regInfo{ inputs: []inputInfo{ {1, 805044223}, // R0 R1 R2 R3 R4 R5 R6 R7 R8 R9 R10 R11 R12 R13 R14 R15 R16 R17 R19 R20 R21 R22 R23 R24 R25 R26 g R30 @@ -19063,6 +19068,7 @@ var opcodeTable = [...]opInfo{ clobberFlags: true, faultOnNilArg0: true, hasSideEffects: true, + unsafePoint: true, reg: regInfo{ inputs: []inputInfo{ {1, 805044223}, // R0 R1 R2 R3 R4 R5 R6 R7 R8 R9 R10 R11 R12 R13 R14 R15 R16 R17 R19 R20 R21 R22 R23 R24 R25 R26 g R30 @@ -19080,6 +19086,7 @@ var opcodeTable = [...]opInfo{ resultNotInArgs: true, faultOnNilArg0: true, hasSideEffects: true, + unsafePoint: true, asm: arm64.AAND, reg: regInfo{ inputs: []inputInfo{ @@ -19097,6 +19104,7 @@ var opcodeTable = [...]opInfo{ resultNotInArgs: true, faultOnNilArg0: true, hasSideEffects: true, + unsafePoint: true, asm: arm64.AORR, reg: regInfo{ inputs: []inputInfo{ @@ -31564,6 +31572,7 @@ func (o Op) String() string { return opcodeTable[o].name } func (o Op) UsesScratch() bool { return opcodeTable[o].usesScratch } func (o Op) SymEffect() SymEffect { return opcodeTable[o].symEffect } func (o Op) IsCall() bool { return opcodeTable[o].call } +func (o Op) UnsafePoint() bool { return opcodeTable[o].unsafePoint } var registers386 = [...]Register{ {0, x86.REG_AX, 0, "AX"},