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 (a] alum.mit.edu> 32 # Copyright (c) 2008 Matteo Frigo 33 # Copyright (c) 2015 Michael Petch <mpetch (a] 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 63 AC_DEFUN([AX_GCC_X86_CPUID], 64 [AX_GCC_X86_CPUID_COUNT($1, 0) 65 ]) 66 67 AC_DEFUN([AX_GCC_X86_CPUID_COUNT], 68 [AC_REQUIRE([AC_PROG_CC]) 69 AC_LANG_PUSH([C]) 70 AC_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])]) 88 AC_LANG_POP([C]) 89 ]) 90
