Revert "cmd/compile: make wasm match other platforms for FP->int32/64 conversions"

This reverts commit 8d810286b3.

Reason for revert: we need to do this more carefully, at minimum gated by a module version

Change-Id: Ia951e2e5ecdd455ea0f17567963c6fab0f4540dc
Reviewed-on: https://go-review.googlesource.com/c/go/+/711840
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Keith Randall <khr@golang.org>

src/cmd/compile/internal/ssa/_gen/Wasm.rules

@@ -76,14 +76,13 @@
 (Cvt32Uto(64|32)F x) => (F(64|32)ConvertI64U (ZeroExt32to64 x))
 (Cvt64Uto(64|32)F ...) => (F(64|32)ConvertI64U ...)
 
-(Cvt32Fto32 ...) => (I32TruncSatF32S ...)
+(Cvt32Fto32 ...) => (I64TruncSatF32S ...)
 (Cvt32Fto64 ...) => (I64TruncSatF32S ...)
-(Cvt64Fto32 ...) => (I32TruncSatF64S ...)
+(Cvt64Fto32 ...) => (I64TruncSatF64S ...)
 (Cvt64Fto64 ...) => (I64TruncSatF64S ...)
-
+(Cvt32Fto32U ...) => (I64TruncSatF32U ...)
-(Cvt32Fto32U ...) => (I32TruncSatF32U ...)
 (Cvt32Fto64U ...) => (I64TruncSatF32U ...)
-(Cvt64Fto32U ...) => (I32TruncSatF64U ...)
+(Cvt64Fto32U ...) => (I64TruncSatF64U ...)
 (Cvt64Fto64U ...) => (I64TruncSatF64U ...)
 
 (Cvt32Fto64F ...) => (F64PromoteF32 ...)

src/cmd/compile/internal/ssa/_gen/WasmOps.go

@@ -223,18 +223,9 @@ func init() {
 		{name: "F64Div", asm: "F64Div", argLength: 2, reg: fp64_21, typ: "Float64"}, // arg0 / arg1
 
 		{name: "I64TruncSatF64S", asm: "I64TruncSatF64S", argLength: 1, reg: regInfo{inputs: []regMask{fp64}, outputs: []regMask{gp}}, typ: "Int64"}, // truncates the float arg0 to a signed integer (saturating)
-		{name: "I64TruncSatF64U", asm: "I64TruncSatF64U", argLength: 1, reg: regInfo{inputs: []regMask{fp64}, outputs: []regMask{gp}}, typ: "Uint64"}, // truncates the float arg0 to an unsigned integer (saturating)
+		{name: "I64TruncSatF64U", asm: "I64TruncSatF64U", argLength: 1, reg: regInfo{inputs: []regMask{fp64}, outputs: []regMask{gp}}, typ: "Int64"}, // truncates the float arg0 to an unsigned integer (saturating)
 		{name: "I64TruncSatF32S", asm: "I64TruncSatF32S", argLength: 1, reg: regInfo{inputs: []regMask{fp32}, outputs: []regMask{gp}}, typ: "Int64"}, // truncates the float arg0 to a signed integer (saturating)
-		{name: "I64TruncSatF32U", asm: "I64TruncSatF32U", argLength: 1, reg: regInfo{inputs: []regMask{fp32}, outputs: []regMask{gp}}, typ: "Uint64"}, // truncates the float arg0 to an unsigned integer (saturating)
+		{name: "I64TruncSatF32U", asm: "I64TruncSatF32U", argLength: 1, reg: regInfo{inputs: []regMask{fp32}, outputs: []regMask{gp}}, typ: "Int64"}, // truncates the float arg0 to an unsigned integer (saturating)
-
-		// It appears to be wasm convention that everything lands in a 64-bit register;
-		// the WASM instructions for these operations produce 32-bit width results, but
-		// wasm/ssa.go widens them appropriately to 64-bit results.
-		{name: "I32TruncSatF64S", asm: "I32TruncSatF64S", argLength: 1, reg: regInfo{inputs: []regMask{fp64}, outputs: []regMask{gp}}, typ: "Int64"},  // truncates the float arg0 to a signed integer (saturating)
-		{name: "I32TruncSatF64U", asm: "I32TruncSatF64U", argLength: 1, reg: regInfo{inputs: []regMask{fp64}, outputs: []regMask{gp}}, typ: "Uint64"}, // truncates the float arg0 to an unsigned integer (saturating)
-		{name: "I32TruncSatF32S", asm: "I32TruncSatF32S", argLength: 1, reg: regInfo{inputs: []regMask{fp32}, outputs: []regMask{gp}}, typ: "Int64"},  // truncates the float arg0 to a signed integer (saturating)
-		{name: "I32TruncSatF32U", asm: "I32TruncSatF32U", argLength: 1, reg: regInfo{inputs: []regMask{fp32}, outputs: []regMask{gp}}, typ: "Uint64"}, // truncates the float arg0 to an unsigned integer (saturating)
-
 		{name: "F32ConvertI64S", asm: "F32ConvertI64S", argLength: 1, reg: regInfo{inputs: []regMask{gp}, outputs: []regMask{fp32}}, typ: "Float32"}, // converts the signed integer arg0 to a float
 		{name: "F32ConvertI64U", asm: "F32ConvertI64U", argLength: 1, reg: regInfo{inputs: []regMask{gp}, outputs: []regMask{fp32}}, typ: "Float32"}, // converts the unsigned integer arg0 to a float
 		{name: "F64ConvertI64S", asm: "F64ConvertI64S", argLength: 1, reg: regInfo{inputs: []regMask{gp}, outputs: []regMask{fp64}}, typ: "Float64"}, // converts the signed integer arg0 to a float

src/cmd/compile/internal/ssa/opGen.go

@@ -2980,10 +2980,6 @@ const (
 	OpWasmI64TruncSatF64U
 	OpWasmI64TruncSatF32S
 	OpWasmI64TruncSatF32U
-	OpWasmI32TruncSatF64S
-	OpWasmI32TruncSatF64U
-	OpWasmI32TruncSatF32S
-	OpWasmI32TruncSatF32U
 	OpWasmF32ConvertI64S
 	OpWasmF32ConvertI64U
 	OpWasmF64ConvertI64S
@@ -40294,58 +40290,6 @@ var opcodeTable = [...]opInfo{
 			},
 		},
 	},
-	{
-		name:   "I32TruncSatF64S",
-		argLen: 1,
-		asm:    wasm.AI32TruncSatF64S,
-		reg: regInfo{
-			inputs: []inputInfo{
-				{0, 281470681743360}, // F16 F17 F18 F19 F20 F21 F22 F23 F24 F25 F26 F27 F28 F29 F30 F31
-			},
-			outputs: []outputInfo{
-				{0, 65535}, // R0 R1 R2 R3 R4 R5 R6 R7 R8 R9 R10 R11 R12 R13 R14 R15
-			},
-		},
-	},
-	{
-		name:   "I32TruncSatF64U",
-		argLen: 1,
-		asm:    wasm.AI32TruncSatF64U,
-		reg: regInfo{
-			inputs: []inputInfo{
-				{0, 281470681743360}, // F16 F17 F18 F19 F20 F21 F22 F23 F24 F25 F26 F27 F28 F29 F30 F31
-			},
-			outputs: []outputInfo{
-				{0, 65535}, // R0 R1 R2 R3 R4 R5 R6 R7 R8 R9 R10 R11 R12 R13 R14 R15
-			},
-		},
-	},
-	{
-		name:   "I32TruncSatF32S",
-		argLen: 1,
-		asm:    wasm.AI32TruncSatF32S,
-		reg: regInfo{
-			inputs: []inputInfo{
-				{0, 4294901760}, // F0 F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 F11 F12 F13 F14 F15
-			},
-			outputs: []outputInfo{
-				{0, 65535}, // R0 R1 R2 R3 R4 R5 R6 R7 R8 R9 R10 R11 R12 R13 R14 R15
-			},
-		},
-	},
-	{
-		name:   "I32TruncSatF32U",
-		argLen: 1,
-		asm:    wasm.AI32TruncSatF32U,
-		reg: regInfo{
-			inputs: []inputInfo{
-				{0, 4294901760}, // F0 F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 F11 F12 F13 F14 F15
-			},
-			outputs: []outputInfo{
-				{0, 65535}, // R0 R1 R2 R3 R4 R5 R6 R7 R8 R9 R10 R11 R12 R13 R14 R15
-			},
-		},
-	},
 	{
 		name:   "F32ConvertI64S",
 		argLen: 1,

src/cmd/compile/internal/ssa/rewriteWasm.go

@@ -120,10 +120,10 @@ func rewriteValueWasm(v *Value) bool {
 		v.Op = OpWasmI64Ctz
 		return true
 	case OpCvt32Fto32:
-		v.Op = OpWasmI32TruncSatF32S
+		v.Op = OpWasmI64TruncSatF32S
 		return true
 	case OpCvt32Fto32U:
-		v.Op = OpWasmI32TruncSatF32U
+		v.Op = OpWasmI64TruncSatF32U
 		return true
 	case OpCvt32Fto64:
 		v.Op = OpWasmI64TruncSatF32S
@@ -143,13 +143,13 @@ func rewriteValueWasm(v *Value) bool {
 	case OpCvt32to64F:
 		return rewriteValueWasm_OpCvt32to64F(v)
 	case OpCvt64Fto32:
-		v.Op = OpWasmI32TruncSatF64S
+		v.Op = OpWasmI64TruncSatF64S
 		return true
 	case OpCvt64Fto32F:
 		v.Op = OpWasmF32DemoteF64
 		return true
 	case OpCvt64Fto32U:
-		v.Op = OpWasmI32TruncSatF64U
+		v.Op = OpWasmI64TruncSatF64U
 		return true
 	case OpCvt64Fto64:
 		v.Op = OpWasmI64TruncSatF64S

src/cmd/compile/internal/wasm/ssa.go

@@ -430,17 +430,6 @@ func ssaGenValueOnStack(s *ssagen.State, v *ssa.Value, extend bool) {
 		getValue64(s, v.Args[0])
 		s.Prog(v.Op.Asm())
 
-		// 32-bit integer conversion results
-	case ssa.OpWasmI32TruncSatF32S, ssa.OpWasmI32TruncSatF64S:
-		getValue64(s, v.Args[0])
-		s.Prog(v.Op.Asm())
-		s.Prog(wasm.AI64ExtendI32S)
-
-	case ssa.OpWasmI32TruncSatF32U, ssa.OpWasmI32TruncSatF64U:
-		getValue64(s, v.Args[0])
-		s.Prog(v.Op.Asm())
-		s.Prog(wasm.AI64ExtendI32U)
-
 	case ssa.OpWasmF32DemoteF64:
 		getValue64(s, v.Args[0])
 		s.Prog(v.Op.Asm())

test/convert5.go

@@ -4,6 +4,11 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !wasm
+
+// TODO fix this to work for wasm
+// Doing more than this, however, expands the change.
+
 package main
 
 import (