| # =========================================================================== |
| # http://www.gnu.org/software/autoconf-archive/ax_gcc_x86_avx_xgetbv.html |
| # =========================================================================== |
| # |
| # SYNOPSIS |
| # |
| # AX_GCC_X86_AVX_XGETBV |
| # |
| # DESCRIPTION |
| # |
| # On later x86 processors with AVX SIMD support, with gcc or a compiler |
| # that has a compatible syntax for inline assembly instructions, run a |
| # small program that executes the xgetbv instruction with input OP. This |
| # can be used to detect if the OS supports AVX instruction usage. |
| # |
| # On output, the values of the eax and edx registers are stored as |
| # hexadecimal strings as "eax:edx" in the cache variable |
| # ax_cv_gcc_x86_avx_xgetbv. |
| # |
| # If the xgetbv instruction fails (because you are running a |
| # cross-compiler, or because you are not using gcc, or because you are on |
| # a processor that doesn't have this instruction), |
| # ax_cv_gcc_x86_avx_xgetbv_OP is set to the string "unknown". |
| # |
| # This macro mainly exists to be used in AX_EXT. |
| # |
| # LICENSE |
| # |
| # Copyright (c) 2013 Michael Petch <mpetch@capp-sysware.com> |
| # |
| # 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 3 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, see <http://www.gnu.org/licenses/>. |
| # |
| # As a special exception, the respective Autoconf Macro's copyright owner |
| # gives unlimited permission to copy, distribute and modify the configure |
| # scripts that are the output of Autoconf when processing the Macro. You |
| # need not follow the terms of the GNU General Public License when using |
| # or distributing such scripts, even though portions of the text of the |
| # Macro appear in them. The GNU General Public License (GPL) does govern |
| # all other use of the material that constitutes the Autoconf Macro. |
| # |
| # This special exception to the GPL applies to versions of the Autoconf |
| # Macro released by the Autoconf Archive. When you make and distribute a |
| # modified version of the Autoconf Macro, you may extend this special |
| # exception to the GPL to apply to your modified version as well. |
| |
| #serial 1 |
| |
| AC_DEFUN([AX_GCC_X86_AVX_XGETBV], |
| [AC_REQUIRE([AC_PROG_CC]) |
| AC_LANG_PUSH([C]) |
| AC_CACHE_CHECK(for x86-AVX xgetbv $1 output, ax_cv_gcc_x86_avx_xgetbv_$1, |
| [AC_RUN_IFELSE([AC_LANG_PROGRAM([#include <stdio.h>], [ |
| int op = $1, eax, edx; |
| FILE *f; |
| /* Opcodes for xgetbv */ |
| __asm__(".byte 0x0f, 0x01, 0xd0" |
| : "=a" (eax), "=d" (edx) |
| : "c" (op)); |
| f = fopen("conftest_xgetbv", "w"); if (!f) return 1; |
| fprintf(f, "%x:%x\n", eax, edx); |
| fclose(f); |
| return 0; |
| ])], |
| [ax_cv_gcc_x86_avx_xgetbv_$1=`cat conftest_xgetbv`; rm -f conftest_xgetbv], |
| [ax_cv_gcc_x86_avx_xgetbv_$1=unknown; rm -f conftest_xgetbv], |
| [ax_cv_gcc_x86_avx_xgetbv_$1=unknown])]) |
| AC_LANG_POP([C]) |
| ]) |