furnace/extern/fftw/simd-support/avx2.c

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/*
* Copyright (c) 2003, 2007-14 Matteo Frigo
* Copyright (c) 2003, 2007-14 Massachusetts Institute of Technology
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include "kernel/ifftw.h"
#if HAVE_AVX2
#if defined(__x86_64__) || defined(_M_X64) || defined(_M_AMD64)
# include "amd64-cpuid.h"
#else
# include "x86-cpuid.h"
#endif
int X(have_simd_avx2_128)(void)
{
static int init = 0, res;
int max_stdfn, eax, ebx, ecx, edx;
if (!init) {
cpuid_all(0,0,&eax,&ebx,&ecx,&edx);
max_stdfn = eax;
if (max_stdfn >= 0x1) {
/* have AVX and OSXSAVE? (implies XGETBV exists) */
cpuid_all(0x1, 0, &eax, &ebx, &ecx, &edx);
if ((ecx & 0x18000000) == 0x18000000) {
/* have AVX2? */
cpuid_all(7,0,&eax,&ebx,&ecx,&edx);
if (ebx & (1 << 5)) {
/* have OS support for XMM, YMM? */
res = ((xgetbv_eax(0) & 0x6) == 0x6);
}
}
}
init = 1;
}
return res;
}
int X(have_simd_avx2)(void)
{
/*
* For now 256-bit AVX2 support is identical to 128-bit.
* This might change in the future if AMD released AVX2-capable
* chips that work better with the 128-bit flavor, but since AMD
* might actually change it to implement 256-bit AVX2 efficiently
* by then we don't want to disable it before we know.
*/
return X(have_simd_avx2_128)();
}
#endif