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| author | Stefan Liebler <stli@linux.vnet.ibm.com> | 2016-08-31 14:54:55 +0200 |
|---|---|---|
| committer | Stefan Liebler <stli@linux.vnet.ibm.com> | 2016-08-31 14:54:55 +0200 |
| commit | e9b424881a4f85284e56d8b561c54ff57a7c1c9b (patch) | |
| tree | f039d44b1026ba426ef87f128c85e2abdb224f36 /sysdeps/s390/configure.ac | |
| parent | aaf30454802855d439f3d4d1a12fd6b905621029 (diff) | |
| download | glibc-e9b424881a4f85284e56d8b561c54ff57a7c1c9b.zip glibc-e9b424881a4f85284e56d8b561c54ff57a7c1c9b.tar.gz glibc-e9b424881a4f85284e56d8b561c54ff57a7c1c9b.tar.bz2 | |
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.
Diffstat (limited to 'sysdeps/s390/configure.ac')
| -rw-r--r-- | sysdeps/s390/configure.ac | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/sysdeps/s390/configure.ac b/sysdeps/s390/configure.ac index 1db6d84..8a782e7 100644 --- a/sysdeps/s390/configure.ac +++ b/sysdeps/s390/configure.ac @@ -86,5 +86,31 @@ 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]) |