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Merge pull request #647 from dbabokin/dispatch2

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CPU check fix
This commit is contained in:
jbrodman
2013-10-28 14:25:41 -07:00
parent 6585a925be 1f0f852fda
commit 6948120094
2 changed files with 147 additions and 1 deletions
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129
check_isa.cpp Normal file
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@@ -0,0 +1,129 @@
/*
Copyright (c) 2013, Intel Corporation
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 Intel Corporation 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.
*/
///////////////////////////////////////////////////////////////////////////////
// //
// This file is a standalone program, which detects the best supported ISA. //
// //
///////////////////////////////////////////////////////////////////////////////
#include <stdio.h>
#if defined(_WIN32) || defined(_WIN64)
#define ISPC_IS_WINDOWS
#include <intrin.h>
#endif
#if !defined (__arm__)
#if !defined(ISPC_IS_WINDOWS)
static void __cpuid(int info[4], int infoType) {
__asm__ __volatile__ ("cpuid"
: "=a" (info[0]), "=b" (info[1]), "=c" (info[2]), "=d" (info[3])
: "0" (infoType));
}
/* Save %ebx in case it's the PIC register */
static void __cpuidex(int info[4], int level, int count) {
__asm__ __volatile__ ("xchg{l}\t{%%}ebx, %1\n\t"
"cpuid\n\t"
"xchg{l}\t{%%}ebx, %1\n\t"
: "=a" (info[0]), "=r" (info[1]), "=c" (info[2]), "=d" (info[3])
: "0" (level), "2" (count));
}
#endif // !ISPC_IS_WINDOWS
static bool __os_has_avx_support() {
#if defined(ISPC_IS_WINDOWS)
// Check if the OS will save the YMM registers
unsigned long long xcrFeatureMask = _xgetbv(_XCR_XFEATURE_ENABLED_MASK);
return (xcrFeatureMask & 6) == 6;
#else // defined(ISPC_IS_WINDOWS)
// Check xgetbv; this uses a .byte sequence instead of the instruction
// directly because older assemblers do not include support for xgetbv and
// there is no easy way to conditionally compile based on the assembler used.
int rEAX, rEDX;
__asm__ __volatile__ (".byte 0x0f, 0x01, 0xd0" : "=a" (rEAX), "=d" (rEDX) : "c" (0));
return (rEAX & 6) == 6;
#endif // !defined(ISPC_IS_WINDOWS)
}
#endif // !__arm__
static const char *
lGetSystemISA() {
#ifdef __arm__
return "ARM NEON";
#else
int info[4];
__cpuid(info, 1);
if ((info[2] & (1 << 28)) != 0 &&
__os_has_avx_support()) { // AVX
// AVX1 for sure....
// Ivy Bridge?
if ((info[2] & (1 << 29)) != 0 && // F16C
(info[2] & (1 << 30)) != 0) { // RDRAND
// So far, so good. AVX2?
// Call cpuid with eax=7, ecx=0
int info2[4];
__cpuidex(info2, 7, 0);
if ((info2[1] & (1 << 5)) != 0) {
return "AVX2 (codename Haswell)";
}
else {
return "AVX1.1 (codename Ivy Bridge)";
}
}
// Regular AVX
return "AVX (codename Sandy Bridge)";
}
else if ((info[2] & (1 << 19)) != 0) {
return "SSE4";
}
else if ((info[3] & (1 << 26)) != 0) {
return "SSE2";
}
else {
return "Error";
}
#endif
}
int main () {
const char* isa = lGetSystemISA();
printf("ISA: %s\n", isa);
return 0;
}

19
ispc.cpp
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@@ -102,6 +102,22 @@ static void __cpuidex(int info[4], int level, int count) {
}
#endif // !ISPC_IS_WINDOWS && !__ARM__
#if !defined(__arm__)
static bool __os_has_avx_support() {
#if defined(ISPC_IS_WINDOWS)
// Check if the OS will save the YMM registers
unsigned long long xcrFeatureMask = _xgetbv(_XCR_XFEATURE_ENABLED_MASK);
return (xcrFeatureMask & 6) == 6;
#else // defined(ISPC_IS_WINDOWS)
// Check xgetbv; this uses a .byte sequence instead of the instruction
// directly because older assemblers do not include support for xgetbv and
// there is no easy way to conditionally compile based on the assembler used.
int rEAX, rEDX;
__asm__ __volatile__ (".byte 0x0f, 0x01, 0xd0" : "=a" (rEAX), "=d" (rEDX) : "c" (0));
return (rEAX & 6) == 6;
#endif // !defined(ISPC_IS_WINDOWS)
}
#endif // !__arm__
static const char *
lGetSystemISA() {
@@ -111,7 +127,8 @@ lGetSystemISA() {
int info[4];
__cpuid(info, 1);
if ((info[2] & (1 << 28)) != 0) { // AVX
if ((info[2] & (1 << 28)) != 0 &&
__os_has_avx_support()) { // AVX
// AVX1 for sure....
// Ivy Bridge?
if ((info[2] & (1 << 29)) != 0 && // F16C