Determine available features through CPUID

This commit is contained in:
Evgenii 2019-09-04 10:28:51 +03:00
parent 16d4da0a1d
commit 63e8eeac86
3 changed files with 130 additions and 1 deletions

69
tz/cpuid_x86.go Normal file
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@ -0,0 +1,69 @@
// Copyright (c) 2009 The Go Authors. All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// +build 386 amd64 amd64p32
package tz
const (
bitOSXSAVE = 1 << 27
bitAVX = 1 << 28
bitAVX2 = 1 << 5
)
func init() {
maxID, _, _, _ := cpuid(0, 0)
if maxID < 1 {
return
}
_, _, ecx1, _ := cpuid(1, 0)
hasOSXSAVE = isSet(ecx1, bitOSXSAVE)
osSupportsAVX := false
if hasOSXSAVE {
eax, _ := xgetbv()
osSupportsAVX = isSet(eax, 1<<1) && isSet(eax, 1<<2)
}
hasAVX = isSet(ecx1, bitAVX) && osSupportsAVX
if maxID < 7 {
return
}
_, ebx7, _, _ := cpuid(7, 0)
hasAVX2 = isSet(ebx7, bitAVX2) && osSupportsAVX
}
func isSet(hwc uint32, value uint32) bool {
return hwc&value != 0
}
func cpuid(eaxArg, ecxArg uint32) (eax, ebx, ecx, edx uint32)
func xgetbv() (eax, edx uint32)

48
tz/cpuid_x86.s Normal file
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@ -0,0 +1,48 @@
// Copyright (c) 2009 The Go Authors. All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include "textflag.h"
// func cpuid(eaxArg, ecxArg uint32) (eax, ebx, ecx, edx uint32)
TEXT ·cpuid(SB), NOSPLIT, $0-24
MOVL eaxArg+0(FP), AX
MOVL ecxArg+4(FP), CX
CPUID
MOVL AX, eax+8(FP)
MOVL BX, ebx+12(FP)
MOVL CX, ecx+16(FP)
MOVL DX, edx+20(FP)
RET
// func xgetbv() (eax, edx uint32)
TEXT ·xgetbv(SB),NOSPLIT,$0-8
MOVL $0, CX
XGETBV
MOVL AX, eax+0(FP)
MOVL DX, edx+4(FP)
RET

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@ -21,6 +21,12 @@ const (
PureGo
)
var (
hasAVX bool
hasAVX2 bool
hasOSXSAVE bool
)
func (impl Implementation) String() string {
switch impl {
case AVX:
@ -53,7 +59,13 @@ func NewWith(impl Implementation) hash.Hash {
// New returns a new hash.Hash computing the Tillich-Zémor checksum.
func New() hash.Hash {
return newAVX2Inline()
if hasAVX2 {
return newAVX2Inline()
} else if hasAVX {
return newAVX()
} else {
return newPure()
}
}
// Sum returns Tillich-Zémor checksum of data.