| GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory. |
| # Local configure fragment for sysdeps/i386. |
| |
| # We no longer support i386 since it lacks the atomic instructions |
| # required to implement NPTL threading. |
| if test "$config_machine" = i386; then |
| AC_MSG_ERROR([ |
| *** ERROR: Support for i386 is deprecated. |
| *** Please use host i786, i686, i585 or i486. |
| *** For example: /src/glibc/configure --host=i686-pc-linux-gnu ..."]) |
| fi |
| |
| # The GNU C Library can't be built for i386. There are several reasons for |
| # this restriction. The primary reason is that i386 lacks the atomic |
| # operations required to support the current NPTL implementation. While it is |
| # possible that such atomic operations could be emulated in the kernel to date |
| # no such work has been done to enable this. Even with NPTL disabled you still |
| # have no atomic.h implementation. Given the declining use of i386 we disable |
| # support for building with `-march=i386' or `-mcpu=i386.' We don't explicitly |
| # check for i386, instead we make sure the compiler has support for inlining |
| # the builtin __sync_val_compare_and_swap. If it does then we should have no |
| # problem building for i386. |
| LIBC_COMPILER_BUILTIN_INLINED( |
| [__sync_val_compare_and_swap], |
| [int a, b, c; __sync_val_compare_and_swap (&a, b, c);], |
| [-O0], |
| [libc_cv_unsupported_i386=no], |
| [AC_MSG_ERROR([ |
| *** Building with -march=i386/-mcpu=i386 is not supported. |
| *** Please use host i786, i686, i586, or i486. |
| *** For example: /source/glibc/configure CFLAGS='-O2 -march=i686' ...])]) |
| |
| AC_CHECK_HEADER([cpuid.h], , |
| [AC_MSG_ERROR([gcc must provide the <cpuid.h> header])], |
| [/* No default includes. */]) |
| |
| dnl Check if -msse4 works. |
| AC_CACHE_CHECK(for SSE4 support, libc_cv_cc_sse4, [dnl |
| LIBC_TRY_CC_OPTION([-msse4], [libc_cv_cc_sse4=yes], [libc_cv_cc_sse4=no]) |
| ]) |
| if test $libc_cv_cc_sse4 = yes; then |
| AC_DEFINE(HAVE_SSE4_SUPPORT) |
| fi |
| LIBC_CONFIG_VAR([config-cflags-sse4], [$libc_cv_cc_sse4]) |
| |
| dnl Check if -Wa,-mtune=i686 works. |
| AC_CACHE_CHECK(for assembler -mtune=i686 support, libc_cv_as_i686, [dnl |
| LIBC_TRY_CC_OPTION([-Wa,-mtune=i686], |
| [libc_cv_as_i686=yes], |
| [libc_cv_as_i686=no]) |
| ]) |
| LIBC_CONFIG_VAR([config-asflags-i686], [$libc_cv_as_i686]) |
| |
| dnl Check if -mavx works. |
| AC_CACHE_CHECK(for AVX support, libc_cv_cc_avx, [dnl |
| LIBC_TRY_CC_OPTION([-mavx], [libc_cv_cc_avx=yes], [libc_cv_cc_avx=no]) |
| ]) |
| if test $libc_cv_cc_avx = yes; then |
| AC_DEFINE(HAVE_AVX_SUPPORT) |
| fi |
| LIBC_CONFIG_VAR([config-cflags-avx], [$libc_cv_cc_avx]) |
| |
| dnl Check if -msse2avx works. |
| AC_CACHE_CHECK(for AVX encoding of SSE instructions, libc_cv_cc_sse2avx, [dnl |
| LIBC_TRY_CC_OPTION([-msse2avx], |
| [libc_cv_cc_sse2avx=yes], |
| [libc_cv_cc_sse2avx=no]) |
| ]) |
| if test $libc_cv_cc_sse2avx = yes; then |
| AC_DEFINE(HAVE_SSE2AVX_SUPPORT) |
| fi |
| LIBC_CONFIG_VAR([config-cflags-sse2avx], [$libc_cv_cc_sse2avx]) |
| |
| dnl Check if -mfma4 works. |
| AC_CACHE_CHECK(for FMA4 support, libc_cv_cc_fma4, [dnl |
| LIBC_TRY_CC_OPTION([-mfma4], [libc_cv_cc_fma4=yes], [libc_cv_cc_fma4=no]) |
| ]) |
| if test $libc_cv_cc_fma4 = yes; then |
| AC_DEFINE(HAVE_FMA4_SUPPORT) |
| fi |
| LIBC_CONFIG_VAR([have-mfma4], [$libc_cv_cc_fma4]) |
| |
| dnl Check if -mno-vzeroupper works. |
| AC_CACHE_CHECK(for -mno-vzeroupper support, libc_cv_cc_novzeroupper, [dnl |
| LIBC_TRY_CC_OPTION([-mno-vzeroupper], |
| [libc_cv_cc_novzeroupper=yes], |
| [libc_cv_cc_novzeroupper=no]) |
| ]) |
| LIBC_CONFIG_VAR([config-cflags-novzeroupper], [$libc_cv_cc_novzeroupper]) |
| |
| dnl It is always possible to access static and hidden symbols in an |
| dnl position independent way. |
| AC_DEFINE(PI_STATIC_AND_HIDDEN) |
