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- # ===========================================================================
- # https://www.gnu.org/software/autoconf-archive/ax_check_x86_features.html
- # ===========================================================================
- #
- # SYNOPSIS
- #
- # AX_CHECK_X86_FEATURES([ACTION-IF-FOUND],[ACTION-IF-NOT-FOUND])
- #
- # DESCRIPTION
- #
- # Checks if the host cpu supports various x86 instruction set, the
- # instructions that will get tested are "mmx, popcnt, sse, sse2, sse3,
- # sse4.1, sse4.2, sse4a, avx, avx2, avx512f, fma, fma4, bmi, bmi2". If the
- # instruction set is supported by the host cpu, the C preprocessor macro
- # HAVE_XXX_INSTRUCTIONS is set to 1. The XXX is up-cased instruction case
- # with dot replaced by underscore. For example, the test for "sse4.2"
- # would export HAVE_SSE4_2_INSTRUCTIONS=1. Also the compiler flag
- # "-msse4.2" would be added to X86_FEATURE_CFLAGS variable, that can be
- # obtained in Makefile.am using @X86_FEATURE_CFLAGS@.
- #
- # If any of the test for the instruction set were succeeded, the configure
- # script would run ACTION-IF-FOUND if it is specified, or append
- # X86_FEATURE_CFLAGS to CFLAGS. If none of the instruction were found,
- # ACTION-IF-NOT-FOUND hook is triggered.
- #
- # This macro requires gcc extended builtin function "__builtin_cpu_init"
- # and "__builtin_cpu_supports" to detect the cpu features. It will error
- # out if the compiler doesn't has these builtins.
- #
- # See also AX_GCC_X86_CPU_SUPPORTS, which is the actual macro that perform
- # the checks for the instruction sets.
- #
- # LICENSE
- #
- # Copyright (c) 2016 Felix Chern <idryman@gmail.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 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, see <https://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 2
-
- AC_DEFUN([AX_CHECK_X86_FEATURES],
- [m4_foreach_w(
- [ax_x86_feature],
- [mmx popcnt sse sse2 sse3 sse4.1 sse4.2 sse4a avx avx2 avx512f fma fma4 bmi bmi2],
- [AX_GCC_X86_CPU_SUPPORTS(ax_x86_feature,
- [X86_FEATURE_CFLAGS="$X86_FEATURE_CFLAGS -m[]ax_x86_feature"],
- [])
- ])
- AC_SUBST([X86_FEATURE_CFLAGS])
- m4_ifval([$1],[$1],
- [CFLAGS="$CFLAGS $X86_FEATURE_CFLAGS"])
- $2
- ])
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