acinclude/ax_gcc_x86_cpuid.m4.htm
author Sam Lantinga <slouken@libsdl.org>
Fri, 26 Aug 2016 12:18:08 -0700
changeset 10226 cb13d22b7f09
parent 5029 5d7d48157be7
permissions -rw-r--r--
Added SDL_PrivateJoystickAdded() and SDL_PrivateJoystickRemoved()
Updated the removal code to iterate over all joystick add messages instead of just the first one.
     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 
    60 AC_DEFUN([AX_GCC_X86_CPUID],
    61 [AC_REQUIRE([AC_PROG_CC])
    62 AC_LANG_PUSH([C])
    63 AC_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])])
    78 AC_LANG_POP([C])
    79 ])