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authorStefan Liebler <stli@linux.vnet.ibm.com>2016-08-31 14:54:55 +0200
committerStefan Liebler <stli@linux.vnet.ibm.com>2016-08-31 14:54:55 +0200
commite9b424881a4f85284e56d8b561c54ff57a7c1c9b (patch)
treef039d44b1026ba426ef87f128c85e2abdb224f36 /config.h.in
parentaaf30454802855d439f3d4d1a12fd6b905621029 (diff)
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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 'config.h.in')
-rw-r--r--config.h.in3
1 files changed, 3 insertions, 0 deletions
diff --git a/config.h.in b/config.h.in
index 856ef6a69c..8cd08b0e89 100644
--- a/config.h.in
+++ b/config.h.in
@@ -70,6 +70,9 @@
 /* Define if assembler supports AVX512DQ.  */
 #undef  HAVE_AVX512DQ_ASM_SUPPORT
 
+/* Define if assembler supports z196 zarch instructions as default on S390.  */
+#undef  HAVE_S390_MIN_Z196_ZARCH_ASM_SUPPORT
+
 /* Define if assembler supports vector instructions on S390.  */
 #undef  HAVE_S390_VX_ASM_SUPPORT