cmd/compile: intrinsify RotateLeft32 on wasm

wasm has 32-bit versions of all integer operations. This change lowers RotateLeft32 to i32.rotl on wasm and intrinsifies the math/bits call. Benchmarking on amd64 under node.js this is ~25% faster. node v10.15.3/amd64 name old time/op new time/op delta RotateLeft 8.37ns ± 1% 8.28ns ± 0% -1.05% (p=0.029 n=4+4) RotateLeft8 11.9ns ± 1% 11.8ns ± 0% ~ (p=0.167 n=5+5) RotateLeft16 11.8ns ± 0% 11.8ns ± 0% ~ (all equal) RotateLeft32 11.9ns ± 1% 8.7ns ± 0% -26.32% (p=0.008 n=5+5) RotateLeft64 8.31ns ± 1% 8.43ns ± 2% ~ (p=0.063 n=5+5) Updates golang#31265 Change-Id: I5b8e155978faeea536c4f6427ac9564d2f096a46 Reviewed-on: https://go-review.googlesource.com/c/go/+/182359 Run-TryBot: Brian Kessler <[email protected]> TryBot-Result: Gobot Gobot <[email protected]> Reviewed-by: Richard Musiol <[email protected]>
tomocy · Sep 1, 2019 · 4bfcc4f · 4bfcc4f
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commit 4bfcc4f
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Showing 7 changed files with 35 additions and 29 deletions.
diff --git a/src/cmd/compile/internal/gc/ssa.go b/src/cmd/compile/internal/gc/ssa.go
@@ -3504,7 +3504,7 @@ func init() {
 		func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
 			return s.newValue2(ssa.OpRotateLeft32, types.Types[TUINT32], args[0], args[1])
 		},
-		sys.AMD64, sys.ARM, sys.ARM64, sys.S390X, sys.PPC64)
+		sys.AMD64, sys.ARM, sys.ARM64, sys.S390X, sys.PPC64, sys.Wasm)
 	addF("math/bits", "RotateLeft64",
 		func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
 			return s.newValue2(ssa.OpRotateLeft64, types.Types[TUINT64], args[0], args[1])

diff --git a/src/cmd/compile/internal/ssa/gen/Wasm.rules b/src/cmd/compile/internal/ssa/gen/Wasm.rules
@@ -147,7 +147,8 @@
 // Lowering rotates
 (RotateLeft8 <t> x (I64Const [c])) -> (Or8 (Lsh8x64 <t> x (I64Const [c&7])) (Rsh8Ux64 <t> x (I64Const [-c&7])))
 (RotateLeft16 <t> x (I64Const [c])) -> (Or16 (Lsh16x64 <t> x (I64Const [c&15])) (Rsh16Ux64 <t> x (I64Const [-c&15])))
-(RotateLeft32 <t> x (I64Const [c])) -> (Or32 (Lsh32x64 <t> x (I64Const [c&31])) (Rsh32Ux64 <t> x (I64Const [-c&31])))
+(RotateLeft32 x y) -> (I32Rotl x y)
+(RotateLeft64 x y) -> (I64Rotl x y)
 
 // Lowering comparisons
 (Less64  x y) -> (I64LtS x y)
@@ -362,8 +363,6 @@
 
 (BitLen64 x) -> (I64Sub (I64Const [64]) (I64Clz x))
 
-(RotateLeft64 x y) -> (I64Rotl x y)
-
 (PopCount64 x) -> (I64Popcnt x)
 (PopCount32 x) -> (I64Popcnt (ZeroExt32to64 x))
 (PopCount16 x) -> (I64Popcnt (ZeroExt16to64 x))

diff --git a/src/cmd/compile/internal/ssa/gen/WasmOps.go b/src/cmd/compile/internal/ssa/gen/WasmOps.go
@@ -206,6 +206,7 @@ func init() {
 
 		{name: "I64Ctz", asm: "I64Ctz", argLength: 1, reg: gp11, typ: "Int64"},       // ctz(arg0)
 		{name: "I64Clz", asm: "I64Clz", argLength: 1, reg: gp11, typ: "Int64"},       // clz(arg0)
+		{name: "I32Rotl", asm: "I32Rotl", argLength: 2, reg: gp21, typ: "Int32"},     // rotl(arg0, arg1)
 		{name: "I64Rotl", asm: "I64Rotl", argLength: 2, reg: gp21, typ: "Int64"},     // rotl(arg0, arg1)
 		{name: "I64Popcnt", asm: "I64Popcnt", argLength: 1, reg: gp11, typ: "Int64"}, // popcnt(arg0)
 	}

diff --git a/src/cmd/compile/internal/ssa/opGen.go b/src/cmd/compile/internal/ssa/opGen.go
diff --git a/src/cmd/compile/internal/ssa/rewriteWasm.go b/src/cmd/compile/internal/ssa/rewriteWasm.go
diff --git a/src/cmd/compile/internal/wasm/ssa.go b/src/cmd/compile/internal/wasm/ssa.go
@@ -299,6 +299,12 @@ func ssaGenValueOnStack(s *gc.SSAGenState, v *ssa.Value, extend bool) {
 		getValue64(s, v.Args[1])
 		s.Prog(v.Op.Asm())
 
+	case ssa.OpWasmI32Rotl:
+		getValue32(s, v.Args[0])
+		getValue32(s, v.Args[1])
+		s.Prog(wasm.AI32Rotl)
+		s.Prog(wasm.AI64ExtendI32U)
+
 	case ssa.OpWasmI64DivS:
 		getValue64(s, v.Args[0])
 		getValue64(s, v.Args[1])

diff --git a/test/codegen/mathbits.go b/test/codegen/mathbits.go
@@ -213,6 +213,7 @@ func RotateLeft32(n uint32) uint32 {
 	// ppc64:"ROTLW"
 	// ppc64le:"ROTLW"
 	// s390x:"RLL"
+	// wasm:"I32Rotl"
 	return bits.RotateLeft32(n, 9)
 }
 
@@ -232,6 +233,7 @@ func RotateLeftVariable(n uint, m int) uint {
 	// ppc64:"ROTL"
 	// ppc64le:"ROTL"
 	// s390x:"RLLG"
+	// wasm:"I64Rotl"
 	return bits.RotateLeft(n, m)
 }
 
@@ -241,6 +243,7 @@ func RotateLeftVariable64(n uint64, m int) uint64 {
 	// ppc64:"ROTL"
 	// ppc64le:"ROTL"
 	// s390x:"RLLG"
+	// wasm:"I64Rotl"
 	return bits.RotateLeft64(n, m)
 }
 
@@ -251,6 +254,7 @@ func RotateLeftVariable32(n uint32, m int) uint32 {
 	// ppc64:"ROTLW"
 	// ppc64le:"ROTLW"
 	// s390x:"RLL"
+	// wasm:"I32Rotl"
 	return bits.RotateLeft32(n, m)
 }