github.com/slayercat/go@v0.0.0-20170428012452-c51559813f61/src/hash/crc32/crc32_amd64p32.go (about)

     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  package crc32
     6  
     7  // This file contains the code to call the SSE 4.2 version of the Castagnoli
     8  // CRC.
     9  
    10  // haveSSE42 is defined in crc32_amd64p32.s and uses CPUID to test for SSE 4.2
    11  // support.
    12  func haveSSE42() bool
    13  
    14  // castagnoliSSE42 is defined in crc32_amd64p32.s and uses the SSE4.2 CRC32
    15  // instruction.
    16  //go:noescape
    17  func castagnoliSSE42(crc uint32, p []byte) uint32
    18  
    19  var sse42 = haveSSE42()
    20  
    21  func archAvailableCastagnoli() bool {
    22  	return sse42
    23  }
    24  
    25  func archInitCastagnoli() {
    26  	if !sse42 {
    27  		panic("not available")
    28  	}
    29  	// No initialization necessary.
    30  }
    31  
    32  func archUpdateCastagnoli(crc uint32, p []byte) uint32 {
    33  	if !sse42 {
    34  		panic("not available")
    35  	}
    36  	return castagnoliSSE42(crc, p)
    37  }
    38  
    39  func archAvailableIEEE() bool                    { return false }
    40  func archInitIEEE()                              { panic("not available") }
    41  func archUpdateIEEE(crc uint32, p []byte) uint32 { panic("not available") }