diff --git a/blake2s_386.go b/blake2s_386.go
index 45ae546..d8f9cea 100644
--- a/blake2s_386.go
+++ b/blake2s_386.go
@@ -6,18 +6,14 @@
 
 package blake2s
 
+import "golang.org/x/sys/cpu"
+
 var (
 	useSSE4  = false
-	useSSSE3 = supportSSSE3()
-	useSSE2  = supportSSE2()
+	useSSSE3 = cpu.X86.HasSSSE3
+	useSSE2  = cpu.X86.HasSSE2
 )
 
-//go:noescape
-func supportSSE2() bool
-
-//go:noescape
-func supportSSSE3() bool
-
 //go:noescape
 func hashBlocksSSE2(h *[8]uint32, c *[2]uint32, flag uint32, blocks []byte)
 
@@ -25,11 +21,12 @@ func hashBlocksSSE2(h *[8]uint32, c *[2]uint32, flag uint32, blocks []byte)
 func hashBlocksSSSE3(h *[8]uint32, c *[2]uint32, flag uint32, blocks []byte)
 
 func hashBlocks(h *[8]uint32, c *[2]uint32, flag uint32, blocks []byte) {
-	if useSSSE3 {
+	switch {
+	case useSSSE3:
 		hashBlocksSSSE3(h, c, flag, blocks)
-	} else if useSSE2 {
+	case useSSE2:
 		hashBlocksSSE2(h, c, flag, blocks)
-	} else {
+	default:
 		hashBlocksGeneric(h, c, flag, blocks)
 	}
 }
diff --git a/blake2s_386.s b/blake2s_386.s
index 0bb65c7..c123e5d 100644
--- a/blake2s_386.s
+++ b/blake2s_386.s
@@ -433,28 +433,3 @@ loop:
 
 	MOVL BP, SP
 	RET
-
-// func supportSSSE3() bool
-TEXT ·supportSSSE3(SB), 4, $0-1
-	MOVL $1, AX
-	CPUID
-	MOVL CX, BX
-	ANDL $0x1, BX      // supports SSE3
-	JZ   FALSE
-	ANDL $0x200, CX    // supports SSSE3
-	JZ   FALSE
-	MOVB $1, ret+0(FP)
-	RET
-
-FALSE:
-	MOVB $0, ret+0(FP)
-	RET
-
-// func supportSSE2() bool
-TEXT ·supportSSE2(SB), 4, $0-1
-	MOVL $1, AX
-	CPUID
-	SHRL $26, DX
-	ANDL $1, DX        // DX != 0 if support SSE2
-	MOVB DX, ret+0(FP)
-	RET
diff --git a/blake2s_amd64.go b/blake2s_amd64.go
index a925e6b..4e8d2d7 100644
--- a/blake2s_amd64.go
+++ b/blake2s_amd64.go
@@ -6,18 +6,14 @@
 
 package blake2s
 
+import "golang.org/x/sys/cpu"
+
 var (
-	useSSE4  = supportSSE4()
-	useSSSE3 = supportSSSE3()
-	useSSE2  = true // Always available on amd64
+	useSSE4  = cpu.X86.HasSSE41
+	useSSSE3 = cpu.X86.HasSSSE3
+	useSSE2  = cpu.X86.HasSSE2
 )
 
-//go:noescape
-func supportSSSE3() bool
-
-//go:noescape
-func supportSSE4() bool
-
 //go:noescape
 func hashBlocksSSE2(h *[8]uint32, c *[2]uint32, flag uint32, blocks []byte)
 
@@ -28,13 +24,14 @@ func hashBlocksSSSE3(h *[8]uint32, c *[2]uint32, flag uint32, blocks []byte)
 func hashBlocksSSE4(h *[8]uint32, c *[2]uint32, flag uint32, blocks []byte)
 
 func hashBlocks(h *[8]uint32, c *[2]uint32, flag uint32, blocks []byte) {
-	if useSSE4 {
+	switch {
+	case useSSE4:
 		hashBlocksSSE4(h, c, flag, blocks)
-	} else if useSSSE3 {
+	case useSSSE3:
 		hashBlocksSSSE3(h, c, flag, blocks)
-	} else if useSSE2 {
+	case useSSE2:
 		hashBlocksSSE2(h, c, flag, blocks)
-	} else {
+	default:
 		hashBlocksGeneric(h, c, flag, blocks)
 	}
 }
diff --git a/blake2s_amd64.s b/blake2s_amd64.s
index 6cdf5a9..8da2802 100644
--- a/blake2s_amd64.s
+++ b/blake2s_amd64.s
@@ -436,28 +436,3 @@ TEXT ·hashBlocksSSSE3(SB), 0, $672-48 // frame = 656 + 16 byte alignment
 TEXT ·hashBlocksSSE4(SB), 0, $32-48 // frame = 16 + 16 byte alignment
 	HASH_BLOCKS(h+0(FP), c+8(FP), flag+16(FP), blocks_base+24(FP), blocks_len+32(FP), BLAKE2s_SSE4)
 	RET
-
-// func supportSSE4() bool
-TEXT ·supportSSE4(SB), 4, $0-1
-	MOVL $1, AX
-	CPUID
-	SHRL $19, CX       // Bit 19 indicates SSE4.1.
-	ANDL $1, CX
-	MOVB CX, ret+0(FP)
-	RET
-
-// func supportSSSE3() bool
-TEXT ·supportSSSE3(SB), 4, $0-1
-	MOVL $1, AX
-	CPUID
-	MOVL CX, BX
-	ANDL $0x1, BX      // Bit zero indicates SSE3 support.
-	JZ   FALSE
-	ANDL $0x200, CX    // Bit nine indicates SSSE3 support.
-	JZ   FALSE
-	MOVB $1, ret+0(FP)
-	RET
-
-FALSE:
-	MOVB $0, ret+0(FP)
-	RET