lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame^] | 1 | GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory. |
| 2 | # Local configure fragment for sysdeps/i386. |
| 3 | |
| 4 | # We no longer support i386 since it lacks the atomic instructions |
| 5 | # required to implement NPTL threading. |
| 6 | if test "$config_machine" = i386; then |
| 7 | AC_MSG_ERROR([ |
| 8 | *** ERROR: Support for i386 is deprecated. |
| 9 | *** Please use host i786, i686, i585 or i486. |
| 10 | *** For example: /src/glibc/configure --host=i686-pc-linux-gnu ..."]) |
| 11 | fi |
| 12 | |
| 13 | # The GNU C Library can't be built for i386. There are several reasons for |
| 14 | # this restriction. The primary reason is that i386 lacks the atomic |
| 15 | # operations required to support the current NPTL implementation. While it is |
| 16 | # possible that such atomic operations could be emulated in the kernel to date |
| 17 | # no such work has been done to enable this. Even with NPTL disabled you still |
| 18 | # have no atomic.h implementation. Given the declining use of i386 we disable |
| 19 | # support for building with `-march=i386' or `-mcpu=i386.' We don't explicitly |
| 20 | # check for i386, instead we make sure the compiler has support for inlining |
| 21 | # the builtin __sync_val_compare_and_swap. If it does then we should have no |
| 22 | # problem building for i386. |
| 23 | LIBC_COMPILER_BUILTIN_INLINED( |
| 24 | [__sync_val_compare_and_swap], |
| 25 | [int a, b, c; __sync_val_compare_and_swap (&a, b, c);], |
| 26 | [-O0], |
| 27 | [libc_cv_unsupported_i386=no], |
| 28 | [AC_MSG_ERROR([ |
| 29 | *** Building with -march=i386/-mcpu=i386 is not supported. |
| 30 | *** Please use host i786, i686, i586, or i486. |
| 31 | *** For example: /source/glibc/configure CFLAGS='-O2 -march=i686' ...])]) |
| 32 | |
| 33 | AC_CHECK_HEADER([cpuid.h], , |
| 34 | [AC_MSG_ERROR([gcc must provide the <cpuid.h> header])], |
| 35 | [/* No default includes. */]) |
| 36 | |
| 37 | dnl Check if -msse4 works. |
| 38 | AC_CACHE_CHECK(for SSE4 support, libc_cv_cc_sse4, [dnl |
| 39 | LIBC_TRY_CC_OPTION([-msse4], [libc_cv_cc_sse4=yes], [libc_cv_cc_sse4=no]) |
| 40 | ]) |
| 41 | if test $libc_cv_cc_sse4 = yes; then |
| 42 | AC_DEFINE(HAVE_SSE4_SUPPORT) |
| 43 | fi |
| 44 | LIBC_CONFIG_VAR([config-cflags-sse4], [$libc_cv_cc_sse4]) |
| 45 | |
| 46 | dnl Check if -Wa,-mtune=i686 works. |
| 47 | AC_CACHE_CHECK(for assembler -mtune=i686 support, libc_cv_as_i686, [dnl |
| 48 | LIBC_TRY_CC_OPTION([-Wa,-mtune=i686], |
| 49 | [libc_cv_as_i686=yes], |
| 50 | [libc_cv_as_i686=no]) |
| 51 | ]) |
| 52 | LIBC_CONFIG_VAR([config-asflags-i686], [$libc_cv_as_i686]) |
| 53 | |
| 54 | dnl Check if -mavx works. |
| 55 | AC_CACHE_CHECK(for AVX support, libc_cv_cc_avx, [dnl |
| 56 | LIBC_TRY_CC_OPTION([-mavx], [libc_cv_cc_avx=yes], [libc_cv_cc_avx=no]) |
| 57 | ]) |
| 58 | if test $libc_cv_cc_avx = yes; then |
| 59 | AC_DEFINE(HAVE_AVX_SUPPORT) |
| 60 | fi |
| 61 | LIBC_CONFIG_VAR([config-cflags-avx], [$libc_cv_cc_avx]) |
| 62 | |
| 63 | dnl Check if -msse2avx works. |
| 64 | AC_CACHE_CHECK(for AVX encoding of SSE instructions, libc_cv_cc_sse2avx, [dnl |
| 65 | LIBC_TRY_CC_OPTION([-msse2avx], |
| 66 | [libc_cv_cc_sse2avx=yes], |
| 67 | [libc_cv_cc_sse2avx=no]) |
| 68 | ]) |
| 69 | if test $libc_cv_cc_sse2avx = yes; then |
| 70 | AC_DEFINE(HAVE_SSE2AVX_SUPPORT) |
| 71 | fi |
| 72 | LIBC_CONFIG_VAR([config-cflags-sse2avx], [$libc_cv_cc_sse2avx]) |
| 73 | |
| 74 | dnl Check if -mfma4 works. |
| 75 | AC_CACHE_CHECK(for FMA4 support, libc_cv_cc_fma4, [dnl |
| 76 | LIBC_TRY_CC_OPTION([-mfma4], [libc_cv_cc_fma4=yes], [libc_cv_cc_fma4=no]) |
| 77 | ]) |
| 78 | if test $libc_cv_cc_fma4 = yes; then |
| 79 | AC_DEFINE(HAVE_FMA4_SUPPORT) |
| 80 | fi |
| 81 | LIBC_CONFIG_VAR([have-mfma4], [$libc_cv_cc_fma4]) |
| 82 | |
| 83 | dnl Check if -mno-vzeroupper works. |
| 84 | AC_CACHE_CHECK(for -mno-vzeroupper support, libc_cv_cc_novzeroupper, [dnl |
| 85 | LIBC_TRY_CC_OPTION([-mno-vzeroupper], |
| 86 | [libc_cv_cc_novzeroupper=yes], |
| 87 | [libc_cv_cc_novzeroupper=no]) |
| 88 | ]) |
| 89 | LIBC_CONFIG_VAR([config-cflags-novzeroupper], [$libc_cv_cc_novzeroupper]) |
| 90 | |
| 91 | dnl Check whether asm supports Intel MPX |
| 92 | AC_CACHE_CHECK(for Intel MPX support, libc_cv_asm_mpx, [dnl |
| 93 | cat > conftest.s <<\EOF |
| 94 | bndmov %bnd0,(%esp) |
| 95 | EOF |
| 96 | if AC_TRY_COMMAND(${CC-cc} -c $ASFLAGS conftest.s 1>&AS_MESSAGE_LOG_FD); then |
| 97 | libc_cv_asm_mpx=yes |
| 98 | else |
| 99 | libc_cv_asm_mpx=no |
| 100 | fi |
| 101 | rm -f conftest*]) |
| 102 | if test $libc_cv_asm_mpx == yes; then |
| 103 | AC_DEFINE(HAVE_MPX_SUPPORT) |
| 104 | fi |
| 105 | |
| 106 | dnl Check if -mavx2 works. |
| 107 | AC_CACHE_CHECK(for AVX2 support, libc_cv_cc_avx2, [dnl |
| 108 | LIBC_TRY_CC_OPTION([-mavx2], [libc_cv_cc_avx2=yes], [libc_cv_cc_avx2=no]) |
| 109 | ]) |
| 110 | if test $libc_cv_cc_avx2 = yes; then |
| 111 | AC_DEFINE(HAVE_AVX2_SUPPORT) |
| 112 | fi |
| 113 | LIBC_CONFIG_VAR([config-cflags-avx2], [$libc_cv_cc_avx2]) |
| 114 | |
| 115 | AC_DEFINE(USE_REGPARMS) |
| 116 | |
| 117 | dnl It is always possible to access static and hidden symbols in an |
| 118 | dnl position independent way. |
| 119 | AC_DEFINE(PI_STATIC_AND_HIDDEN) |