1# =========================================================================== 2# https://www.gnu.org/software/autoconf-archive/ax_gcc_x86_cpuid.html 3# =========================================================================== 4# 5# SYNOPSIS 6# 7# AX_GCC_X86_CPUID(OP) 8# AX_GCC_X86_CPUID_COUNT(OP, COUNT) 9# 10# DESCRIPTION 11# 12# On Pentium and later x86 processors, with gcc or a compiler that has a 13# compatible syntax for inline assembly instructions, run a small program 14# that executes the cpuid instruction with input OP. This can be used to 15# detect the CPU type. AX_GCC_X86_CPUID_COUNT takes an additional COUNT 16# parameter that gets passed into register ECX before calling cpuid. 17# 18# On output, the values of the eax, ebx, ecx, and edx registers are stored 19# as hexadecimal strings as "eax:ebx:ecx:edx" in the cache variable 20# ax_cv_gcc_x86_cpuid_OP. 21# 22# If the cpuid instruction fails (because you are running a 23# cross-compiler, or because you are not using gcc, or because you are on 24# a processor that doesn't have this instruction), ax_cv_gcc_x86_cpuid_OP 25# is set to the string "unknown". 26# 27# This macro mainly exists to be used in AX_GCC_ARCHFLAG. 28# 29# LICENSE 30# 31# Copyright (c) 2008 Steven G. Johnson <stevenj@alum.mit.edu> 32# Copyright (c) 2008 Matteo Frigo 33# Copyright (c) 2015 Michael Petch <mpetch@capp-sysware.com> 34# 35# This program is free software: you can redistribute it and/or modify it 36# under the terms of the GNU General Public License as published by the 37# Free Software Foundation, either version 3 of the License, or (at your 38# option) any later version. 39# 40# This program is distributed in the hope that it will be useful, but 41# WITHOUT ANY WARRANTY; without even the implied warranty of 42# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General 43# Public License for more details. 44# 45# You should have received a copy of the GNU General Public License along 46# with this program. If not, see <https://www.gnu.org/licenses/>. 47# 48# As a special exception, the respective Autoconf Macro's copyright owner 49# gives unlimited permission to copy, distribute and modify the configure 50# scripts that are the output of Autoconf when processing the Macro. You 51# need not follow the terms of the GNU General Public License when using 52# or distributing such scripts, even though portions of the text of the 53# Macro appear in them. The GNU General Public License (GPL) does govern 54# all other use of the material that constitutes the Autoconf Macro. 55# 56# This special exception to the GPL applies to versions of the Autoconf 57# Macro released by the Autoconf Archive. When you make and distribute a 58# modified version of the Autoconf Macro, you may extend this special 59# exception to the GPL to apply to your modified version as well. 60 61#serial 10 62 63AC_DEFUN([AX_GCC_X86_CPUID], 64[AX_GCC_X86_CPUID_COUNT($1, 0) 65]) 66 67AC_DEFUN([AX_GCC_X86_CPUID_COUNT], 68[AC_REQUIRE([AC_PROG_CC]) 69AC_LANG_PUSH([C]) 70AC_CACHE_CHECK(for x86 cpuid $1 output, ax_cv_gcc_x86_cpuid_$1, 71 [AC_RUN_IFELSE([AC_LANG_PROGRAM([#include <stdio.h>], [ 72 int op = $1, level = $2, eax, ebx, ecx, edx; 73 FILE *f; 74 __asm__ __volatile__ ("xchg %%ebx, %1\n" 75 "cpuid\n" 76 "xchg %%ebx, %1\n" 77 : "=a" (eax), "=r" (ebx), "=c" (ecx), "=d" (edx) 78 : "a" (op), "2" (level)); 79 80 f = fopen("conftest_cpuid", "w"); if (!f) return 1; 81 fprintf(f, "%x:%x:%x:%x\n", eax, ebx, ecx, edx); 82 fclose(f); 83 return 0; 84])], 85 [ax_cv_gcc_x86_cpuid_$1=`cat conftest_cpuid`; rm -f conftest_cpuid], 86 [ax_cv_gcc_x86_cpuid_$1=unknown; rm -f conftest_cpuid], 87 [ax_cv_gcc_x86_cpuid_$1=unknown])]) 88AC_LANG_POP([C]) 89]) 90