glibc/sysdeps/s390/configure.ac
Stefan Liebler e9b424881a S390: Do not set FE_INEXACT with feraiseexcept (FE_OWERFLOW|FE_UNDERFLOW).
On s390 feraiseexcept (FE_OVERFLOW|FE_UNDERFLOW) sets FE_INEXACT, too.
This patch uses z196 zarch load rounded instruction which can suppress
FE_INEXACT exception if gcc has z196 support in used configuration.
Otherwise FE_INEXACT flag is set as before. The gcc support is tested
in a new configure-check.

A comment in fsetexcptflg.c is corrected as new exceptions are not
executed with the next floating-point instruction if fpc is set with
_FPU_SETCW macro. It seems the comment was copied e.g. from
sysdeps/x86_64/fpu/fsetexcptflg.c file.

ChangeLog:

	* config.h.in (HAVE_S390_MIN_Z196_ZARCH_ASM_SUPPORT):
	New undefine.
	* sysdeps/s390/configure.ac: Add test for z196 zarch support.
	* sysdeps/s390/configure: Regenerated.
	* sysdeps/s390/fpu/fraiseexcpt.c (__feraiseexcept): Use ledbra
	instruction for raising over-/underflow if z196 zarch is supported
	by default.
	* sysdeps/s390/fpu/fsetexcptflg.c (fesetexceptflag):
	Correct comment.
2016-08-31 14:54:55 +02:00

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GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory.
# Local configure fragment for sysdeps/s390.
dnl It is always possible to access static and hidden symbols in an
dnl position independent way.
AC_DEFINE(PI_STATIC_AND_HIDDEN)
dnl Accept as 2.24 or newer.
AC_CHECK_PROG_VER(AS, $AS, --version,
[GNU assembler.* \([0-9]*\.[0-9.]*\)],
[2.2[4-9]*|2.[3-9][0-9]*|[3-9].*|[1-9][0-9]*], critic_missing="$critic_missing The program AS is required in version >= 2.24 for target S390.")
AC_CACHE_CHECK(for __builtin_tbegin, libc_cv_gcc_builtin_tbegin, [dnl
cat > conftest.c <<\EOF
#include <htmintrin.h>
void testtransaction ()
{
if (__builtin_tbegin (0) == _HTM_TBEGIN_STARTED)
{
__builtin_tend ();
}
}
EOF
dnl
dnl test, if the tbegin instruction is used by __builtin_tbegin
if AC_TRY_COMMAND([${CC-cc} -mhtm -O2 -S conftest.c -o - | grep -w tbegin > /dev/null]) ;
then
libc_cv_gcc_builtin_tbegin=yes
else
libc_cv_gcc_builtin_tbegin=no
fi
rm -f conftest* ])
if test "$enable_lock_elision" = yes && test "$libc_cv_gcc_builtin_tbegin" = no ; then
critic_missing="$critic_missing The used GCC has no support for __builtin_tbegin, which is needed for lock-elision on target S390."
fi
AC_CACHE_CHECK(for S390 vector instruction support, libc_cv_asm_s390_vx, [dnl
cat > conftest.c <<\EOF
void testvecinsn ()
{
__asm__ (".machine \"z13\" \n\t"
".machinemode \"zarch_nohighgprs\" \n\t"
"vistrbs %%v16,%%v17 \n\t"
"locghie %%r1,0" : :);
}
EOF
dnl
dnl test, if assembler supports S390 vector instructions
if AC_TRY_COMMAND([${CC-cc} --shared conftest.c -o conftest.o &> /dev/null]) ;
then
libc_cv_asm_s390_vx=yes
else
libc_cv_asm_s390_vx=no
fi
rm -f conftest* ])
if test "$libc_cv_asm_s390_vx" = yes ;
then
AC_DEFINE(HAVE_S390_VX_ASM_SUPPORT)
else
AC_MSG_WARN([Use binutils with vector-support in order to use optimized implementations.])
fi
AC_CACHE_CHECK(for S390 vector support in gcc, libc_cv_gcc_s390_vx, [dnl
cat > conftest.c <<\EOF
void testvecclobber ()
{
__asm__ ("" : : : "v16");
}
EOF
dnl
dnl test, if gcc supports S390 vector registers as clobber in inline assembly
if AC_TRY_COMMAND([${CC-cc} --shared conftest.c -o conftest.o &> /dev/null]) ;
then
libc_cv_gcc_s390_vx=yes
else
libc_cv_gcc_s390_vx=no
fi
rm -f conftest* ])
if test "$libc_cv_gcc_s390_vx" = yes ;
then
AC_DEFINE(HAVE_S390_VX_GCC_SUPPORT)
fi
AC_CACHE_CHECK(for S390 z196 zarch instruction support as default,
libc_cv_asm_s390_min_z196_zarch, [dnl
cat > conftest.c <<\EOF
float testinsn (double e)
{
float d;
__asm__ ("ledbra %0,5,%1,4" : "=f" (d) : "f" (e) );
return d;
}
EOF
dnl
dnl test, if assembler supports S390 z196 zarch instructions as default
if AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS --shared conftest.c
-o conftest.o &> /dev/null]) ;
then
libc_cv_asm_s390_min_z196_zarch=yes
else
libc_cv_asm_s390_min_z196_zarch=no
fi
rm -f conftest* ])
if test "$libc_cv_asm_s390_min_z196_zarch" = yes ;
then
AC_DEFINE(HAVE_S390_MIN_Z196_ZARCH_ASM_SUPPORT)
fi
test -n "$critic_missing" && AC_MSG_ERROR([
*** $critic_missing])