glibc/sysdeps/x86/configure.ac
H.J. Lu 29807a271e x86: Properly set x86 minimum ISA level [BZ #31883]
Properly set libc_cv_have_x86_isa_level in shell for MINIMUM_X86_ISA_LEVEL
defined as

(__X86_ISA_V1 + __X86_ISA_V2 + __X86_ISA_V3 + __X86_ISA_V4)

Also set __X86_ISA_V2 to 1 for i386 if __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8
is defined.  There are no changes in config.h nor in config.make on x86-64.
On i386, -march=x86-64-v2 with GCC generates

 #define MINIMUM_X86_ISA_LEVEL 2

in config.h and

have-x86-isa-level = 2

in config.make.  This fixes BZ #31883.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
2024-06-12 14:27:54 -07:00

125 lines
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GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory.
# Local configure fragment for sysdeps/x86.
# Check if linker supports x86 ISA level.
AC_CACHE_CHECK([for linker x86 ISA level support],
libc_cv_include_x86_isa_level, [dnl
cat > conftest1.S <<EOF
#ifdef __LP64__
# define P2ALIGN 3
#else
# define P2ALIGN 2
#endif
.section ".note.gnu.property", "a"
.p2align P2ALIGN
.long 1f - 0f /* name length. */
.long 4f - 1f /* data length. */
/* NT_GNU_PROPERTY_TYPE_0 */
.long 5 /* note type. */
0:
.asciz "GNU" /* vendor name. */
1:
.p2align P2ALIGN
/* GNU_PROPERTY_X86_ISA_1_NEEDED */
.long 0xc0008002 /* pr_type. */
.long 3f - 2f /* pr_datasz. */
2:
.long 0x1
3:
.p2align P2ALIGN
4:
EOF
cat > conftest2.S <<EOF
#ifdef __LP64__
# define P2ALIGN 3
#else
# define P2ALIGN 2
#endif
.section ".note.gnu.property", "a"
.p2align P2ALIGN
.long 1f - 0f /* name length. */
.long 4f - 1f /* data length. */
/* NT_GNU_PROPERTY_TYPE_0 */
.long 5 /* note type. */
0:
.asciz "GNU" /* vendor name. */
1:
.p2align P2ALIGN
/* GNU_PROPERTY_X86_ISA_1_NEEDED */
.long 0xc0008002 /* pr_type. */
.long 3f - 2f /* pr_datasz. */
2:
.long 0x2
3:
.p2align P2ALIGN
4:
EOF
libc_cv_include_x86_isa_level=no
if AC_TRY_COMMAND(${CC-cc} $CFLAGS $CPPFLAGS -nostartfiles -nostdlib -r -o conftest conftest1.S conftest2.S); then
count=`LC_ALL=C $READELF -n conftest | grep NT_GNU_PROPERTY_TYPE_0 | wc -l`
if test "$count" = 1; then
libc_cv_include_x86_isa_level=yes
fi
fi
rm -f conftest*])
if test $libc_cv_include_x86_isa_level = yes; then
AC_DEFINE(INCLUDE_X86_ISA_LEVEL)
AC_CACHE_CHECK([for LAHF/SAHF instruction support],
libc_cv_have_x86_lahf_sahf, [dnl
libc_cv_have_x86_lahf_sahf=no
if AC_TRY_COMMAND(${CC-cc} $CFLAGS $CPPFLAGS -fverbose-asm -S -o - -x c /dev/null) | grep -qE '(-msahf\b|-march=x86-64-v)'; then
libc_cv_have_x86_lahf_sahf=yes
fi])
if test $libc_cv_have_x86_lahf_sahf = yes; then
AC_DEFINE(HAVE_X86_LAHF_SAHF)
ISAFLAG="-DHAVE_X86_LAHF_SAHF"
fi
AC_CACHE_CHECK([for MOVBE instruction support],
libc_cv_have_x86_movbe, [dnl
libc_cv_have_x86_movbe=no
if AC_TRY_COMMAND(${CC-cc} $CFLAGS $CPPFLAGS -fverbose-asm -S -o - -x c /dev/null) | grep -qE '(-mmovbe\b|-march=x86-64-v(@<:@3-9@:>@|@<:@1-9@:>@@<:@0-9@:>@))'; then
libc_cv_have_x86_movbe=yes
fi])
if test $libc_cv_have_x86_movbe = yes; then
AC_DEFINE(HAVE_X86_MOVBE)
ISAFLAG="$ISAFLAG -DHAVE_X86_MOVBE"
fi
# Check for ISA level support.
AC_CACHE_CHECK([for ISA level support],
libc_cv_have_x86_isa_level, [dnl
cat > conftest.c <<EOF
#include <sysdeps/x86/isa-level.h>
#if MINIMUM_X86_ISA_LEVEL >= 4
libc_cv_have_x86_isa_level=4
#elif MINIMUM_X86_ISA_LEVEL == 3
libc_cv_have_x86_isa_level=3
#elif MINIMUM_X86_ISA_LEVEL == 2
libc_cv_have_x86_isa_level=2
#elif defined __x86_64__
libc_cv_have_x86_isa_level=baseline
#elif MINIMUM_X86_ISA_LEVEL == 1
libc_cv_have_x86_isa_level=1
#else
libc_cv_have_x86_isa_level=0
#endif
EOF
eval `${CC-cc} $CFLAGS $CPPFLAGS $ISAFLAG -I$srcdir -E conftest.c | grep libc_cv_have_x86_isa_level`
rm -rf conftest*])
elif test $base_machine = x86_64; then
libc_cv_have_x86_isa_level=baseline
else
libc_cv_have_x86_isa_level=0
fi
if test $libc_cv_have_x86_isa_level = baseline; then
AC_DEFINE_UNQUOTED(MINIMUM_X86_ISA_LEVEL, 1)
else
AC_DEFINE_UNQUOTED(MINIMUM_X86_ISA_LEVEL, $libc_cv_have_x86_isa_level)
fi
LIBC_CONFIG_VAR([have-x86-isa-level], [$libc_cv_have_x86_isa_level])
LIBC_CONFIG_VAR([x86-isa-level-3-or-above], [3 4])
LIBC_CONFIG_VAR([enable-x86-isa-level], [$libc_cv_include_x86_isa_level])
dnl Static PIE is supported.
AC_DEFINE(SUPPORT_STATIC_PIE)