replace custom CPU feature detection

This change replaces the custom CPU feature detection code using the new `x/sys/cpu` package. Fixes #6
minio · Apr 30, 2018 · 342af21 · 342af21
1 parent 9c7e959
commit 342af21
Show file tree

Hide file tree

Showing 4 changed files with 19 additions and 35 deletions.
diff --git a/highwayhashAVX2_amd64.go b/highwayhashAVX2_amd64.go
@@ -7,18 +7,14 @@
 
 package highwayhash
 
+import "golang.org/x/sys/cpu"
+
 var (
-	useSSE4 = supportsSSE4()
-	useAVX2 = supportsAVX2()
+	useSSE4 = cpu.X86.HasSSE41
+	useAVX2 = cpu.X86.HasAVX2
 	useNEON = false
 )
 
-//go:noescape
-func supportsSSE4() bool
-
-//go:noescape
-func supportsAVX2() bool
-
 //go:noescape
 func initializeSSE4(state *[16]uint64, key []byte)
 
@@ -38,31 +34,34 @@ func finalizeSSE4(out []byte, state *[16]uint64)
 func finalizeAVX2(out []byte, state *[16]uint64)
 
 func initialize(state *[16]uint64, key []byte) {
-	if useAVX2 {
+	switch {
+	case useAVX2:
 		initializeAVX2(state, key)
-	} else if useSSE4 {
+	case useSSE4:
 		initializeSSE4(state, key)
-	} else {
+	default:
 		initializeGeneric(state, key)
 	}
 }
 
 func update(state *[16]uint64, msg []byte) {
-	if useAVX2 {
+	switch {
+	case useAVX2:
 		updateAVX2(state, msg)
-	} else if useSSE4 {
+	case useSSE4:
 		updateSSE4(state, msg)
-	} else {
+	default:
 		updateGeneric(state, msg)
 	}
 }
 
 func finalize(out []byte, state *[16]uint64) {
-	if useAVX2 {
+	switch {
+	case useAVX2:
 		finalizeAVX2(out, state)
-	} else if useSSE4 {
+	case useSSE4:
 		finalizeSSE4(out, state)
-	} else {
+	default:
 		finalizeGeneric(out, state)
 	}
 }
diff --git a/highwayhashAVX2_amd64.s b/highwayhashAVX2_amd64.s
@@ -248,8 +248,3 @@ hash64:
 	MOVQ DX, 0(BX)
 	RET
 
-// func supportsAVX2() bool
-TEXT ·supportsAVX2(SB), 4, $0-1
-	MOVQ runtime·support_avx2(SB), AX
-	MOVB AX, ret+0(FP)
-	RET
diff --git a/highwayhash_amd64.go b/highwayhash_amd64.go
@@ -7,15 +7,14 @@
 
 package highwayhash
 
+import "golang.org/x/sys/cpu"
+
 var (
-	useSSE4 = supportsSSE4()
+	useSSE4 = cpu.X86.HasSSE41
 	useAVX2 = false
 	useNEON = false
 )
 
-//go:noescape
-func supportsSSE4() bool
-
 //go:noescape
 func initializeSSE4(state *[16]uint64, key []byte)
 

diff --git a/highwayhash_amd64.s b/highwayhash_amd64.s
@@ -292,12 +292,3 @@ hash64:
 	MOVQ  m10, DX
 	MOVQ  DX, 0(BX)
 	RET
-
-// func supportsSSE4() bool
-TEXT ·supportsSSE4(SB), 4, $0-1
-	MOVL $1, AX
-	CPUID
-	SHRL $19, CX       // Bit 19 indicates SSE4 support
-	ANDL $1, CX        // CX != 0 if support SSE4
-	MOVB CX, ret+0(FP)
-	RET