ax_gcc_x86_cpuid.m4.htm (3313B)
1# =========================================================================== 2# http://www.gnu.org/software/autoconf-archive/ax_gcc_x86_cpuid.html 3# =========================================================================== 4# 5# SYNOPSIS 6# 7# AX_GCC_X86_CPUID(OP) 8# 9# DESCRIPTION 10# 11# On Pentium and later x86 processors, with gcc or a compiler that has a 12# compatible syntax for inline assembly instructions, run a small program 13# that executes the cpuid instruction with input OP. This can be used to 14# detect the CPU type. 15# 16# On output, the values of the eax, ebx, ecx, and edx registers are stored 17# as hexadecimal strings as "eax:ebx:ecx:edx" in the cache variable 18# ax_cv_gcc_x86_cpuid_OP. 19# 20# If the cpuid 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), ax_cv_gcc_x86_cpuid_OP 23# is set to the string "unknown". 24# 25# This macro mainly exists to be used in AX_GCC_ARCHFLAG. 26# 27# LICENSE 28# 29# Copyright (c) 2008 Steven G. Johnson <stevenj@alum.mit.edu> 30# Copyright (c) 2008 Matteo Frigo 31# 32# This program is free software: you can redistribute it and/or modify it 33# under the terms of the GNU General Public License as published by the 34# Free Software Foundation, either version 3 of the License, or (at your 35# option) any later version. 36# 37# This program is distributed in the hope that it will be useful, but 38# WITHOUT ANY WARRANTY; without even the implied warranty of 39# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General 40# Public License for more details. 41# 42# You should have received a copy of the GNU General Public License along 43# with this program. If not, see <http://www.gnu.org/licenses/>. 44# 45# As a special exception, the respective Autoconf Macro's copyright owner 46# gives unlimited permission to copy, distribute and modify the configure 47# scripts that are the output of Autoconf when processing the Macro. You 48# need not follow the terms of the GNU General Public License when using 49# or distributing such scripts, even though portions of the text of the 50# Macro appear in them. The GNU General Public License (GPL) does govern 51# all other use of the material that constitutes the Autoconf Macro. 52# 53# This special exception to the GPL applies to versions of the Autoconf 54# Macro released by the Autoconf Archive. When you make and distribute a 55# modified version of the Autoconf Macro, you may extend this special 56# exception to the GPL to apply to your modified version as well. 57 58#serial 7 59 60AC_DEFUN([AX_GCC_X86_CPUID], 61[AC_REQUIRE([AC_PROG_CC]) 62AC_LANG_PUSH([C]) 63AC_CACHE_CHECK(for x86 cpuid $1 output, ax_cv_gcc_x86_cpuid_$1, 64 [AC_RUN_IFELSE([AC_LANG_PROGRAM([#include <stdio.h>], [ 65 int op = $1, eax, ebx, ecx, edx; 66 FILE *f; 67 __asm__("cpuid" 68 : "=a" (eax), "=b" (ebx), "=c" (ecx), "=d" (edx) 69 : "a" (op)); 70 f = fopen("conftest_cpuid", "w"); if (!f) return 1; 71 fprintf(f, "%x:%x:%x:%x\n", eax, ebx, ecx, edx); 72 fclose(f); 73 return 0; 74])], 75 [ax_cv_gcc_x86_cpuid_$1=`cat conftest_cpuid`; rm -f conftest_cpuid], 76 [ax_cv_gcc_x86_cpuid_$1=unknown; rm -f conftest_cpuid], 77 [ax_cv_gcc_x86_cpuid_$1=unknown])]) 78AC_LANG_POP([C]) 79])