2 files changed, 66 insertions, 0 deletions
diff --git a/src/pkg/hash/crc32/crc32_amd64p32.s b/src/pkg/hash/crc32/crc32_amd64p32.s
new file mode 100644
index 000000000..e34f20867
--- /dev/null
+++ b/src/pkg/hash/crc32/crc32_amd64p32.s
@@ -0,0 +1,64 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "../../../cmd/ld/textflag.h"
+
+// func castagnoliSSE42(crc uint32, p []byte) uint32
+TEXT ·castagnoliSSE42(SB),NOSPLIT,$0
+	MOVL crc+0(FP), AX  // CRC value
+	MOVL p+4(FP), SI  // data pointer
+	MOVL p_len+8(FP), CX  // len(p)
+
+	NOTL AX
+
+	/* If there's less than 8 bytes to process, we do it byte-by-byte. */
+	CMPQ CX, $8
+	JL cleanup
+
+	/* Process individual bytes until the input is 8-byte aligned. */
+startup:
+	MOVQ SI, BX
+	ANDQ $7, BX
+	JZ aligned
+
+	CRC32B (SI), AX
+	DECQ CX
+	INCQ SI
+	JMP startup
+
+aligned:
+	/* The input is now 8-byte aligned and we can process 8-byte chunks. */
+	CMPQ CX, $8
+	JL cleanup
+
+	CRC32Q (SI), AX
+	ADDQ $8, SI
+	SUBQ $8, CX
+	JMP aligned
+
+cleanup:
+	/* We may have some bytes left over that we process one at a time. */
+	CMPQ CX, $0
+	JE done
+
+	CRC32B (SI), AX
+	INCQ SI
+	DECQ CX
+	JMP cleanup
+
+done:
+	NOTL AX
+	MOVL AX, ret+16(FP)
+	RET
+
+// func haveSSE42() bool
+TEXT ·haveSSE42(SB),NOSPLIT,$0
+	XORQ AX, AX
+	INCL AX
+	CPUID
+	SHRQ $20, CX
+	ANDQ $1, CX
+	MOVB CX, ret+0(FP)
+	RET
+
diff --git a/src/pkg/hash/crc32/crc32_amd64.go b/src/pkg/hash/crc32/crc32_amd64x.go
index b5bc6d3cf..b7e359930 100644
--- a/src/pkg/hash/crc32/crc32_amd64.go
+++ b/src/pkg/hash/crc32/crc32_amd64x.go
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// +build amd64 amd64p32
+
 package crc32
 
 // This file contains the code to call the SSE 4.2 version of the Castagnoli