| xf.li | bdd93d5 | 2023-05-12 07:10:14 -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 "$config_machine" = i386; then |
| 7 | AC_MSG_ERROR([ |
| 8 | *** ERROR: Support for i386 is deprecated. |
| 9 | *** Please use host i786, i686, i585 or i486. |
| 10 | *** For example: /src/glibc/configure --host=i686-pc-linux-gnu ..."]) |
| 11 | fi |
| 12 | |
| 13 | # The GNU C Library can't be built for i386. There are several reasons for |
| 14 | # this restriction. The primary reason is that i386 lacks the atomic |
| 15 | # operations required to support the current NPTL implementation. While it is |
| 16 | # possible that such atomic operations could be emulated in the kernel to date |
| 17 | # no such work has been done to enable this. Even with NPTL disabled you still |
| 18 | # have no atomic.h implementation. Given the declining use of i386 we disable |
| 19 | # support for building with `-march=i386' or `-mcpu=i386.' We don't explicitly |
| 20 | # check for i386, instead we make sure the compiler has support for inlining |
| 21 | # the builtin __sync_val_compare_and_swap. If it does then we should have no |
| 22 | # problem building for i386. |
| 23 | LIBC_COMPILER_BUILTIN_INLINED( |
| 24 | [__sync_val_compare_and_swap], |
| 25 | [int a, b, c; __sync_val_compare_and_swap (&a, b, c);], |
| 26 | [-O0], |
| 27 | [libc_cv_unsupported_i386=no], |
| 28 | [AC_MSG_ERROR([ |
| 29 | *** Building with -march=i386/-mcpu=i386 is not supported. |
| 30 | *** Please use host i786, i686, i586, or i486. |
| 31 | *** For example: /source/glibc/configure CFLAGS='-O2 -march=i686' ...])]) |
| 32 | |
| 33 | dnl Check whether asm supports Intel MPX |
| 34 | AC_CACHE_CHECK(for Intel MPX support, libc_cv_asm_mpx, [dnl |
| 35 | cat > conftest.s <<\EOF |
| 36 | bndmov %bnd0,(%esp) |
| 37 | EOF |
| 38 | if AC_TRY_COMMAND(${CC-cc} -c $ASFLAGS conftest.s 1>&AS_MESSAGE_LOG_FD); then |
| 39 | libc_cv_asm_mpx=yes |
| 40 | else |
| 41 | libc_cv_asm_mpx=no |
| 42 | fi |
| 43 | rm -f conftest*]) |
| 44 | if test $libc_cv_asm_mpx == yes; then |
| 45 | AC_DEFINE(HAVE_MPX_SUPPORT) |
| 46 | fi |
| 47 | |
| 48 | AC_DEFINE(USE_REGPARMS) |
| 49 | |
| 50 | dnl It is always possible to access static and hidden symbols in an |
| 51 | dnl position independent way. |
| 52 | AC_DEFINE(PI_STATIC_AND_HIDDEN) |