Thomas Tsou | 3eaae80 | 2013-08-20 19:31:14 -0400 | [diff] [blame^] | 1 | # =========================================================================== |
| 2 | # http://www.gnu.org/software/autoconf-archive/ax_gcc_x86_avx_xgetbv.html |
| 3 | # =========================================================================== |
| 4 | # |
| 5 | # SYNOPSIS |
| 6 | # |
| 7 | # AX_GCC_X86_AVX_XGETBV |
| 8 | # |
| 9 | # DESCRIPTION |
| 10 | # |
| 11 | # On later x86 processors with AVX SIMD support, with gcc or a compiler |
| 12 | # that has a compatible syntax for inline assembly instructions, run a |
| 13 | # small program that executes the xgetbv instruction with input OP. This |
| 14 | # can be used to detect if the OS supports AVX instruction usage. |
| 15 | # |
| 16 | # On output, the values of the eax and edx registers are stored as |
| 17 | # hexadecimal strings as "eax:edx" in the cache variable |
| 18 | # ax_cv_gcc_x86_avx_xgetbv. |
| 19 | # |
| 20 | # If the xgetbv instruction fails (because you are running a |
| 21 | # cross-compiler, or because you are not using gcc, or because you are on |
| 22 | # a processor that doesn't have this instruction), |
| 23 | # ax_cv_gcc_x86_avx_xgetbv_OP is set to the string "unknown". |
| 24 | # |
| 25 | # This macro mainly exists to be used in AX_EXT. |
| 26 | # |
| 27 | # LICENSE |
| 28 | # |
| 29 | # Copyright (c) 2013 Michael Petch <mpetch@capp-sysware.com> |
| 30 | # |
| 31 | # This program is free software: you can redistribute it and/or modify it |
| 32 | # under the terms of the GNU General Public License as published by the |
| 33 | # Free Software Foundation, either version 3 of the License, or (at your |
| 34 | # option) any later version. |
| 35 | # |
| 36 | # This program is distributed in the hope that it will be useful, but |
| 37 | # WITHOUT ANY WARRANTY; without even the implied warranty of |
| 38 | # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General |
| 39 | # Public License for more details. |
| 40 | # |
| 41 | # You should have received a copy of the GNU General Public License along |
| 42 | # with this program. If not, see <http://www.gnu.org/licenses/>. |
| 43 | # |
| 44 | # As a special exception, the respective Autoconf Macro's copyright owner |
| 45 | # gives unlimited permission to copy, distribute and modify the configure |
| 46 | # scripts that are the output of Autoconf when processing the Macro. You |
| 47 | # need not follow the terms of the GNU General Public License when using |
| 48 | # or distributing such scripts, even though portions of the text of the |
| 49 | # Macro appear in them. The GNU General Public License (GPL) does govern |
| 50 | # all other use of the material that constitutes the Autoconf Macro. |
| 51 | # |
| 52 | # This special exception to the GPL applies to versions of the Autoconf |
| 53 | # Macro released by the Autoconf Archive. When you make and distribute a |
| 54 | # modified version of the Autoconf Macro, you may extend this special |
| 55 | # exception to the GPL to apply to your modified version as well. |
| 56 | |
| 57 | #serial 1 |
| 58 | |
| 59 | AC_DEFUN([AX_GCC_X86_AVX_XGETBV], |
| 60 | [AC_REQUIRE([AC_PROG_CC]) |
| 61 | AC_LANG_PUSH([C]) |
| 62 | AC_CACHE_CHECK(for x86-AVX xgetbv $1 output, ax_cv_gcc_x86_avx_xgetbv_$1, |
| 63 | [AC_RUN_IFELSE([AC_LANG_PROGRAM([#include <stdio.h>], [ |
| 64 | int op = $1, eax, edx; |
| 65 | FILE *f; |
| 66 | /* Opcodes for xgetbv */ |
| 67 | __asm__(".byte 0x0f, 0x01, 0xd0" |
| 68 | : "=a" (eax), "=d" (edx) |
| 69 | : "c" (op)); |
| 70 | f = fopen("conftest_xgetbv", "w"); if (!f) return 1; |
| 71 | fprintf(f, "%x:%x\n", eax, edx); |
| 72 | fclose(f); |
| 73 | return 0; |
| 74 | ])], |
| 75 | [ax_cv_gcc_x86_avx_xgetbv_$1=`cat conftest_xgetbv`; rm -f conftest_xgetbv], |
| 76 | [ax_cv_gcc_x86_avx_xgetbv_$1=unknown; rm -f conftest_xgetbv], |
| 77 | [ax_cv_gcc_x86_avx_xgetbv_$1=unknown])]) |
| 78 | AC_LANG_POP([C]) |
| 79 | ]) |