From: Richard Musiol Date: Sun, 24 Mar 2019 11:14:27 +0000 (+0100) Subject: cmd/compile: add saturating conversions on wasm X-Git-Tag: go1.13beta1~800 X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=cf8cc7f63c7ddefb666a6e8d99a4843d3277db9f;p=gostls13.git cmd/compile: add saturating conversions on wasm This change adds the GOWASM option "satconv" to enable the generation of experimental saturating (non-trapping) float-to-int conversions. It improves the performance of the conversion by 42%. Previously the conversions had already been augmented with helper functions to have saturating behavior. Now Wasm.rules is always using the new operation names and wasm/ssa.go is falling back to the helpers if the feature is not enabled. The feature is in phase 4 of the WebAssembly proposal process: https://github.com/WebAssembly/meetings/blob/master/process/phases.md More information on the feature can be found at: https://github.com/WebAssembly/nontrapping-float-to-int-conversions/blob/master/proposals/nontrapping-float-to-int-conversion/Overview.md Change-Id: Ic6c3688017054ede804b02b6b0ffd4a02ef33ad7 Reviewed-on: https://go-review.googlesource.com/c/go/+/170119 Reviewed-by: Cherry Zhang Run-TryBot: Cherry Zhang TryBot-Result: Gobot Gobot --- diff --git a/doc/install-source.html b/doc/install-source.html index 9c73b925b1..6a0c3844ae 100644 --- a/doc/install-source.html +++ b/doc/install-source.html @@ -645,6 +645,7 @@ for which the compiler will target. The default is power8. The default is to use no experimental features.

diff --git a/src/cmd/compile/internal/ssa/gen/Wasm.rules b/src/cmd/compile/internal/ssa/gen/Wasm.rules index 72f4805edf..a832abf0fb 100644 --- a/src/cmd/compile/internal/ssa/gen/Wasm.rules +++ b/src/cmd/compile/internal/ssa/gen/Wasm.rules @@ -84,14 +84,14 @@ (Cvt64Uto32F x) -> (LoweredRound32F (F64ConvertI64U x)) (Cvt64Uto64F x) -> (F64ConvertI64U x) -(Cvt32Fto32 x) -> (I64TruncF64S x) -(Cvt32Fto64 x) -> (I64TruncF64S x) -(Cvt64Fto32 x) -> (I64TruncF64S x) -(Cvt64Fto64 x) -> (I64TruncF64S x) -(Cvt32Fto32U x) -> (I64TruncF64U x) -(Cvt32Fto64U x) -> (I64TruncF64U x) -(Cvt64Fto32U x) -> (I64TruncF64U x) -(Cvt64Fto64U x) -> (I64TruncF64U x) +(Cvt32Fto32 x) -> (I64TruncSatF64S x) +(Cvt32Fto64 x) -> (I64TruncSatF64S x) +(Cvt64Fto32 x) -> (I64TruncSatF64S x) +(Cvt64Fto64 x) -> (I64TruncSatF64S x) +(Cvt32Fto32U x) -> (I64TruncSatF64U x) +(Cvt32Fto64U x) -> (I64TruncSatF64U x) +(Cvt64Fto32U x) -> (I64TruncSatF64U x) +(Cvt64Fto64U x) -> (I64TruncSatF64U x) (Cvt32Fto64F x) -> x (Cvt64Fto32F x) -> (LoweredRound32F x) diff --git a/src/cmd/compile/internal/ssa/gen/WasmOps.go b/src/cmd/compile/internal/ssa/gen/WasmOps.go index 4e5f076575..de035c985a 100644 --- a/src/cmd/compile/internal/ssa/gen/WasmOps.go +++ b/src/cmd/compile/internal/ssa/gen/WasmOps.go @@ -187,8 +187,8 @@ func init() { {name: "F64Mul", asm: "F64Mul", argLength: 2, reg: fp21, typ: "Float64"}, // arg0 * arg1 {name: "F64Div", asm: "F64Div", argLength: 2, reg: fp21, typ: "Float64"}, // arg0 / arg1 - {name: "I64TruncF64S", asm: "I64TruncF64S", argLength: 1, reg: regInfo{inputs: []regMask{fp}, outputs: []regMask{gp}}, typ: "Int64"}, // truncates the float arg0 to a signed integer - {name: "I64TruncF64U", asm: "I64TruncF64U", argLength: 1, reg: regInfo{inputs: []regMask{fp}, outputs: []regMask{gp}}, typ: "Int64"}, // truncates the float arg0 to an unsigned integer + {name: "I64TruncSatF64S", asm: "I64TruncSatF64S", argLength: 1, reg: regInfo{inputs: []regMask{fp}, outputs: []regMask{gp}}, typ: "Int64"}, // truncates the float arg0 to a signed integer (saturating) + {name: "I64TruncSatF64U", asm: "I64TruncSatF64U", argLength: 1, reg: regInfo{inputs: []regMask{fp}, outputs: []regMask{gp}}, typ: "Int64"}, // truncates the float arg0 to an unsigned integer (saturating) {name: "F64ConvertI64S", asm: "F64ConvertI64S", argLength: 1, reg: regInfo{inputs: []regMask{gp}, outputs: []regMask{fp}}, typ: "Float64"}, // converts the signed integer arg0 to a float {name: "F64ConvertI64U", asm: "F64ConvertI64U", argLength: 1, reg: regInfo{inputs: []regMask{gp}, outputs: []regMask{fp}}, typ: "Float64"}, // converts the unsigned integer arg0 to a float diff --git a/src/cmd/compile/internal/ssa/opGen.go b/src/cmd/compile/internal/ssa/opGen.go index 214d68757c..06dcb2d7ac 100644 --- a/src/cmd/compile/internal/ssa/opGen.go +++ b/src/cmd/compile/internal/ssa/opGen.go @@ -2132,8 +2132,8 @@ const ( OpWasmF64Sub OpWasmF64Mul OpWasmF64Div - OpWasmI64TruncF64S - OpWasmI64TruncF64U + OpWasmI64TruncSatF64S + OpWasmI64TruncSatF64U OpWasmF64ConvertI64S OpWasmF64ConvertI64U OpWasmI64Extend8S @@ -28676,9 +28676,9 @@ var opcodeTable = [...]opInfo{ }, }, { - name: "I64TruncF64S", + name: "I64TruncSatF64S", argLen: 1, - asm: wasm.AI64TruncF64S, + asm: wasm.AI64TruncSatF64S, reg: regInfo{ inputs: []inputInfo{ {0, 4294901760}, // F0 F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 F11 F12 F13 F14 F15 @@ -28689,9 +28689,9 @@ var opcodeTable = [...]opInfo{ }, }, { - name: "I64TruncF64U", + name: "I64TruncSatF64U", argLen: 1, - asm: wasm.AI64TruncF64U, + asm: wasm.AI64TruncSatF64U, reg: regInfo{ inputs: []inputInfo{ {0, 4294901760}, // F0 F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 F11 F12 F13 F14 F15 diff --git a/src/cmd/compile/internal/ssa/rewriteWasm.go b/src/cmd/compile/internal/ssa/rewriteWasm.go index fe85922e31..d02ed1e87f 100644 --- a/src/cmd/compile/internal/ssa/rewriteWasm.go +++ b/src/cmd/compile/internal/ssa/rewriteWasm.go @@ -1095,10 +1095,10 @@ func rewriteValueWasm_OpCtz8NonZero_0(v *Value) bool { func rewriteValueWasm_OpCvt32Fto32_0(v *Value) bool { // match: (Cvt32Fto32 x) // cond: - // result: (I64TruncF64S x) + // result: (I64TruncSatF64S x) for { x := v.Args[0] - v.reset(OpWasmI64TruncF64S) + v.reset(OpWasmI64TruncSatF64S) v.AddArg(x) return true } @@ -1106,10 +1106,10 @@ func rewriteValueWasm_OpCvt32Fto32_0(v *Value) bool { func rewriteValueWasm_OpCvt32Fto32U_0(v *Value) bool { // match: (Cvt32Fto32U x) // cond: - // result: (I64TruncF64U x) + // result: (I64TruncSatF64U x) for { x := v.Args[0] - v.reset(OpWasmI64TruncF64U) + v.reset(OpWasmI64TruncSatF64U) v.AddArg(x) return true } @@ -1117,10 +1117,10 @@ func rewriteValueWasm_OpCvt32Fto32U_0(v *Value) bool { func rewriteValueWasm_OpCvt32Fto64_0(v *Value) bool { // match: (Cvt32Fto64 x) // cond: - // result: (I64TruncF64S x) + // result: (I64TruncSatF64S x) for { x := v.Args[0] - v.reset(OpWasmI64TruncF64S) + v.reset(OpWasmI64TruncSatF64S) v.AddArg(x) return true } @@ -1140,10 +1140,10 @@ func rewriteValueWasm_OpCvt32Fto64F_0(v *Value) bool { func rewriteValueWasm_OpCvt32Fto64U_0(v *Value) bool { // match: (Cvt32Fto64U x) // cond: - // result: (I64TruncF64U x) + // result: (I64TruncSatF64U x) for { x := v.Args[0] - v.reset(OpWasmI64TruncF64U) + v.reset(OpWasmI64TruncSatF64U) v.AddArg(x) return true } @@ -1215,10 +1215,10 @@ func rewriteValueWasm_OpCvt32to64F_0(v *Value) bool { func rewriteValueWasm_OpCvt64Fto32_0(v *Value) bool { // match: (Cvt64Fto32 x) // cond: - // result: (I64TruncF64S x) + // result: (I64TruncSatF64S x) for { x := v.Args[0] - v.reset(OpWasmI64TruncF64S) + v.reset(OpWasmI64TruncSatF64S) v.AddArg(x) return true } @@ -1237,10 +1237,10 @@ func rewriteValueWasm_OpCvt64Fto32F_0(v *Value) bool { func rewriteValueWasm_OpCvt64Fto32U_0(v *Value) bool { // match: (Cvt64Fto32U x) // cond: - // result: (I64TruncF64U x) + // result: (I64TruncSatF64U x) for { x := v.Args[0] - v.reset(OpWasmI64TruncF64U) + v.reset(OpWasmI64TruncSatF64U) v.AddArg(x) return true } @@ -1248,10 +1248,10 @@ func rewriteValueWasm_OpCvt64Fto32U_0(v *Value) bool { func rewriteValueWasm_OpCvt64Fto64_0(v *Value) bool { // match: (Cvt64Fto64 x) // cond: - // result: (I64TruncF64S x) + // result: (I64TruncSatF64S x) for { x := v.Args[0] - v.reset(OpWasmI64TruncF64S) + v.reset(OpWasmI64TruncSatF64S) v.AddArg(x) return true } @@ -1259,10 +1259,10 @@ func rewriteValueWasm_OpCvt64Fto64_0(v *Value) bool { func rewriteValueWasm_OpCvt64Fto64U_0(v *Value) bool { // match: (Cvt64Fto64U x) // cond: - // result: (I64TruncF64U x) + // result: (I64TruncSatF64U x) for { x := v.Args[0] - v.reset(OpWasmI64TruncF64U) + v.reset(OpWasmI64TruncSatF64U) v.AddArg(x) return true } diff --git a/src/cmd/compile/internal/wasm/ssa.go b/src/cmd/compile/internal/wasm/ssa.go index 7575df548a..63eb319edb 100644 --- a/src/cmd/compile/internal/wasm/ssa.go +++ b/src/cmd/compile/internal/wasm/ssa.go @@ -10,6 +10,7 @@ import ( "cmd/compile/internal/types" "cmd/internal/obj" "cmd/internal/obj/wasm" + "cmd/internal/objabi" ) func Init(arch *gc.Arch) { @@ -307,15 +308,23 @@ func ssaGenValueOnStack(s *gc.SSAGenState, v *ssa.Value) { } s.Prog(wasm.AI64DivS) - case ssa.OpWasmI64TruncF64S: + case ssa.OpWasmI64TruncSatF64S: getValue64(s, v.Args[0]) - p := s.Prog(wasm.ACall) - p.To = obj.Addr{Type: obj.TYPE_MEM, Name: obj.NAME_EXTERN, Sym: gc.WasmTruncS} + if objabi.GOWASM.SatConv { + s.Prog(v.Op.Asm()) + } else { + p := s.Prog(wasm.ACall) + p.To = obj.Addr{Type: obj.TYPE_MEM, Name: obj.NAME_EXTERN, Sym: gc.WasmTruncS} + } - case ssa.OpWasmI64TruncF64U: + case ssa.OpWasmI64TruncSatF64U: getValue64(s, v.Args[0]) - p := s.Prog(wasm.ACall) - p.To = obj.Addr{Type: obj.TYPE_MEM, Name: obj.NAME_EXTERN, Sym: gc.WasmTruncU} + if objabi.GOWASM.SatConv { + s.Prog(v.Op.Asm()) + } else { + p := s.Prog(wasm.ACall) + p.To = obj.Addr{Type: obj.TYPE_MEM, Name: obj.NAME_EXTERN, Sym: gc.WasmTruncU} + } case ssa.OpWasmF64Neg, ssa.OpWasmF64ConvertI64S, ssa.OpWasmF64ConvertI64U, diff --git a/src/cmd/go/alldocs.go b/src/cmd/go/alldocs.go index de07d910d8..008e306efb 100644 --- a/src/cmd/go/alldocs.go +++ b/src/cmd/go/alldocs.go @@ -1581,7 +1581,7 @@ // Valid values are hardfloat (default), softfloat. // GOWASM // For GOARCH=wasm, comma-separated list of experimental WebAssembly features to use. -// Valid values are: signext. +// Valid values are satconv, signext. // // Special-purpose environment variables: // diff --git a/src/cmd/go/internal/help/helpdoc.go b/src/cmd/go/internal/help/helpdoc.go index eb663e99b6..98d4bd0382 100644 --- a/src/cmd/go/internal/help/helpdoc.go +++ b/src/cmd/go/internal/help/helpdoc.go @@ -565,7 +565,7 @@ Architecture-specific environment variables: Valid values are hardfloat (default), softfloat. GOWASM For GOARCH=wasm, comma-separated list of experimental WebAssembly features to use. - Valid values are: signext. + Valid values are satconv, signext. Special-purpose environment variables: diff --git a/src/cmd/internal/obj/wasm/a.out.go b/src/cmd/internal/obj/wasm/a.out.go index 29ea87f3b0..c686f1d6f0 100644 --- a/src/cmd/internal/obj/wasm/a.out.go +++ b/src/cmd/internal/obj/wasm/a.out.go @@ -216,6 +216,15 @@ const ( AI64Extend16S AI64Extend32S + AI32TruncSatF32S // opcode 0xFC 0x00 + AI32TruncSatF32U + AI32TruncSatF64S + AI32TruncSatF64U + AI64TruncSatF32S + AI64TruncSatF32U + AI64TruncSatF64S + AI64TruncSatF64U + ALast // Sentinel: End of low-level WebAssembly instructions. ARESUMEPOINT diff --git a/src/cmd/internal/obj/wasm/anames.go b/src/cmd/internal/obj/wasm/anames.go index fb4b72c398..c8552e7f18 100644 --- a/src/cmd/internal/obj/wasm/anames.go +++ b/src/cmd/internal/obj/wasm/anames.go @@ -182,6 +182,14 @@ var Anames = []string{ "I64Extend8S", "I64Extend16S", "I64Extend32S", + "I32TruncSatF32S", + "I32TruncSatF32U", + "I32TruncSatF64S", + "I32TruncSatF64U", + "I64TruncSatF32S", + "I64TruncSatF32U", + "I64TruncSatF64S", + "I64TruncSatF64U", "Last", "RESUMEPOINT", "CALLNORESUME", diff --git a/src/cmd/internal/obj/wasm/wasmobj.go b/src/cmd/internal/obj/wasm/wasmobj.go index dded62a4be..0474e3b4b1 100644 --- a/src/cmd/internal/obj/wasm/wasmobj.go +++ b/src/cmd/internal/obj/wasm/wasmobj.go @@ -886,7 +886,7 @@ func assemble(ctxt *obj.Link, s *obj.LSym, newprog obj.ProgAlloc) { } switch { - case p.As < AUnreachable || p.As >= ALast: + case p.As < AUnreachable: panic(fmt.Sprintf("unexpected assembler op: %s", p.As)) case p.As < AEnd: w.WriteByte(byte(p.As - AUnreachable + 0x00)) @@ -894,8 +894,13 @@ func assemble(ctxt *obj.Link, s *obj.LSym, newprog obj.ProgAlloc) { w.WriteByte(byte(p.As - AEnd + 0x0B)) case p.As < AI32Load: w.WriteByte(byte(p.As - ADrop + 0x1A)) - default: + case p.As < AI32TruncSatF32S: w.WriteByte(byte(p.As - AI32Load + 0x28)) + case p.As < ALast: + w.WriteByte(0xFC) + w.WriteByte(byte(p.As - AI32TruncSatF32S + 0x00)) + default: + panic(fmt.Sprintf("unexpected assembler op: %s", p.As)) } switch p.As { diff --git a/src/cmd/internal/objabi/util.go b/src/cmd/internal/objabi/util.go index 02f9d9273a..e28447d141 100644 --- a/src/cmd/internal/objabi/util.go +++ b/src/cmd/internal/objabi/util.go @@ -79,10 +79,14 @@ func goppc64() int { type gowasmFeatures struct { SignExt bool + SatConv bool } func (f *gowasmFeatures) String() string { var flags []string + if f.SatConv { + flags = append(flags, "satconv") + } if f.SignExt { flags = append(flags, "signext") } @@ -92,6 +96,8 @@ func (f *gowasmFeatures) String() string { func gowasm() (f gowasmFeatures) { for _, opt := range strings.Split(envOr("GOWASM", ""), ",") { switch opt { + case "satconv": + f.SatConv = true case "signext": f.SignExt = true case "":