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author | Joseph Myers <joseph@codesourcery.com> | 2016-03-09 00:30:59 +0000 |
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committer | Joseph Myers <joseph@codesourcery.com> | 2016-03-09 00:30:59 +0000 |
commit | 613c92b3b59df6a06784cde1d4f410cef0b6da96 (patch) | |
tree | efdcc70a56baf3ed21f7278b72efed5d2e8a9b27 /ChangeLog | |
parent | 3bd80c0de2f8e7ca8020d37739339636d169957e (diff) | |
download | glibc-613c92b3b59df6a06784cde1d4f410cef0b6da96.tar.gz glibc-613c92b3b59df6a06784cde1d4f410cef0b6da96.tar.xz glibc-613c92b3b59df6a06784cde1d4f410cef0b6da96.zip |
Fix ldbl-128ibm nearbyintl in non-default rounding modes (bug 19790).
The ldbl-128ibm implementation of nearbyintl uses logic that only works in round-to-nearest mode. This contrasts with rintl, which works in all rounding modes. Now, arguably nearbyintl could simply be aliased to rintl, given that spurious "inexact" is generally allowed for ldbl-128ibm, even for the underlying arithmetic operations. But given that the only point of nearbyintl is to avoid "inexact", this patch follows the more conservative approach of adding conditionals to the rintl implementation to make it suitable for use to implement nearbyintl, then builds it for nearbyintl with USE_AS_NEARBYINTL defined. The test test-nearbyint-except-2 shows up issues when traps on "inexact" are enabled, which turn out to be problems with the powerpc fenv_private.h implementation (two functions that should disable exception traps potentially failing to do so in some cases); this patch duly fixes that as well (I don't see any other existing cases where this would be user-visible; there isn't much use of *_NOEX, *hold* etc. in libm that requires exceptions to be discarded and not trapped on). Tested for powerpc. [BZ #19790] * sysdeps/ieee754/ldbl-128ibm/s_rintl.c [USE_AS_NEARBYINTL] (rintl): Define as macro. [USE_AS_NEARBYINTL] (__rintl): Likewise. (__rintl) [USE_AS_NEARBYINTL]: Use SET_RESTORE_ROUND_NOEX instead of fesetround. Ensure results are evaluated before end of scope. * sysdeps/ieee754/ldbl-128ibm/s_nearbyintl.c: Define USE_AS_NEARBYINTL and include s_rintl.c. * sysdeps/powerpc/fpu/fenv_private.h (libc_feholdsetround_ppc): Disable exception traps in new environment. (libc_feholdsetround_ppc_ctx): Likewise.
Diffstat (limited to 'ChangeLog')
-rw-r--r-- | ChangeLog | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/ChangeLog b/ChangeLog index 73a49a06e0..a6be76213e 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,17 @@ +2016-03-09 Joseph Myers <joseph@codesourcery.com> + + [BZ #19790] + * sysdeps/ieee754/ldbl-128ibm/s_rintl.c [USE_AS_NEARBYINTL] + (rintl): Define as macro. + [USE_AS_NEARBYINTL] (__rintl): Likewise. + (__rintl) [USE_AS_NEARBYINTL]: Use SET_RESTORE_ROUND_NOEX instead + of fesetround. Ensure results are evaluated before end of scope. + * sysdeps/ieee754/ldbl-128ibm/s_nearbyintl.c: Define + USE_AS_NEARBYINTL and include s_rintl.c. + * sysdeps/powerpc/fpu/fenv_private.h (libc_feholdsetround_ppc): + Disable exception traps in new environment. + (libc_feholdsetround_ppc_ctx): Likewise. + 2016-03-08 Roland McGrath <roland@hack.frob.com> * sysdeps/x86_64/tst-audit10.c: #include <cpu-features.h>. |