diff options
Diffstat (limited to 'm4/ax_gcc_x86_cpuid.m4')
| -rw-r--r-- | m4/ax_gcc_x86_cpuid.m4 | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/m4/ax_gcc_x86_cpuid.m4 b/m4/ax_gcc_x86_cpuid.m4 new file mode 100644 index 0000000..df95465 --- /dev/null +++ b/m4/ax_gcc_x86_cpuid.m4 @@ -0,0 +1,89 @@ +# =========================================================================== +# https://www.gnu.org/software/autoconf-archive/ax_gcc_x86_cpuid.html +# =========================================================================== +# +# SYNOPSIS +# +# AX_GCC_X86_CPUID(OP) +# AX_GCC_X86_CPUID_COUNT(OP, COUNT) +# +# DESCRIPTION +# +# On Pentium and later x86 processors, with gcc or a compiler that has a +# compatible syntax for inline assembly instructions, run a small program +# that executes the cpuid instruction with input OP. This can be used to +# detect the CPU type. AX_GCC_X86_CPUID_COUNT takes an additional COUNT +# parameter that gets passed into register ECX before calling cpuid. +# +# On output, the values of the eax, ebx, ecx, and edx registers are stored +# as hexadecimal strings as "eax:ebx:ecx:edx" in the cache variable +# ax_cv_gcc_x86_cpuid_OP. +# +# If the cpuid 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_cpuid_OP +# is set to the string "unknown". +# +# This macro mainly exists to be used in AX_GCC_ARCHFLAG. +# +# LICENSE +# +# Copyright (c) 2008 Steven G. Johnson <stevenj@alum.mit.edu> +# Copyright (c) 2008 Matteo Frigo +# Copyright (c) 2015 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 <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 10 + +AC_DEFUN([AX_GCC_X86_CPUID], +[AX_GCC_X86_CPUID_COUNT($1, 0) +]) + +AC_DEFUN([AX_GCC_X86_CPUID_COUNT], +[AC_REQUIRE([AC_PROG_CC]) +AC_LANG_PUSH([C]) +AC_CACHE_CHECK(for x86 cpuid $1 output, ax_cv_gcc_x86_cpuid_$1, + [AC_RUN_IFELSE([AC_LANG_PROGRAM([#include <stdio.h>], [ + int op = $1, level = $2, eax, ebx, ecx, edx; + FILE *f; + __asm__ __volatile__ ("xchg %%ebx, %1\n" + "cpuid\n" + "xchg %%ebx, %1\n" + : "=a" (eax), "=r" (ebx), "=c" (ecx), "=d" (edx) + : "a" (op), "2" (level)); + + f = fopen("conftest_cpuid", "w"); if (!f) return 1; + fprintf(f, "%x:%x:%x:%x\n", eax, ebx, ecx, edx); + fclose(f); + return 0; +])], + [ax_cv_gcc_x86_cpuid_$1=`cat conftest_cpuid`; rm -f conftest_cpuid], + [ax_cv_gcc_x86_cpuid_$1=unknown; rm -f conftest_cpuid], + [ax_cv_gcc_x86_cpuid_$1=unknown])]) +AC_LANG_POP([C]) +]) |