libgo/go/hash/crc32/crc32_amd64x.go

   1 // Copyright 2011 The Go Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style
   3 // license that can be found in the LICENSE file.
   4
   5 // +build amd64 amd64p32
   6
   7 package crc32
   8
   9 // This file contains the code to call the SSE 4.2 version of the Castagnoli
  10 // CRC.
  11
  12 // haveSSE42 is defined in crc_amd64.s and uses CPUID to test for SSE 4.2
  13 // support.
  14 func haveSSE42() bool
  15
  16 // castagnoliSSE42 is defined in crc_amd64.s and uses the SSE4.2 CRC32
  17 // instruction.
  18 func castagnoliSSE42(crc uint32, p []byte) uint32
  19
  20 var sse42 = haveSSE42()
  21
  22 func updateCastagnoli(crc uint32, p []byte) uint32 {
  23         if sse42 {
  24                 return castagnoliSSE42(crc, p)
  25         }
  26         return update(crc, castagnoliTable, p)
  27 }