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| author | Joseph Myers <joseph@codesourcery.com> | 2016-05-24 17:46:55 +0000 |
|---|---|---|
| committer | Joseph Myers <joseph@codesourcery.com> | 2016-05-24 17:46:55 +0000 |
| commit | 078d1cf8accf8e74390c3b091549afa4efbb113e (patch) | |
| tree | 1a098004bed55cfe49d11ac8f79642cd44a436aa /sysdeps/ieee754/ldbl-96/s_roundl.c | |
| parent | 876c5bd30cf44ab47ee46c08d06e6ba9ab2b338f (diff) | |
| download | glibc-078d1cf8accf8e74390c3b091549afa4efbb113e.tar.gz glibc-078d1cf8accf8e74390c3b091549afa4efbb113e.tar.xz glibc-078d1cf8accf8e74390c3b091549afa4efbb113e.zip | |
Do not raise "inexact" from generic round (bug 15479).
C99 and C11 allow but do not require ceil, floor, round and trunc to raise the "inexact" exception for noninteger arguments. TS 18661-1 requires that this exception not be raised by these functions. This aligns them with general IEEE semantics, where "inexact" is only raised if the final step of rounding the infinite-precision result to the result type is inexact; for these functions, the infinite-precision integer result is always representable in the result type, so "inexact" should never be raised. The generic implementations of ceil, floor and round functions contain code to force "inexact" to be raised. This patch removes it for round functions to align them with TS 18661-1 in this regard. The tests *are* updated by this patch; there are fewer architecture-specific versions than for ceil and floor, and I fixed the powerpc ones some time ago. If any others still have the issue, as shown by tests for round failing with spurious exceptions, they can be fixed separately by architecture maintainers or others. Tested for x86_64, x86 and mips64. [BZ #15479] * sysdeps/ieee754/dbl-64/s_round.c (huge): Remove variable. (__round): Do not force "inexact" exception. * sysdeps/ieee754/dbl-64/wordsize-64/s_round.c (huge): Remove variable. (__round): Do not force "inexact" exception. * sysdeps/ieee754/flt-32/s_roundf.c (huge): Remove variable. (__roundf): Do not force "inexact" exception. * sysdeps/ieee754/ldbl-128/s_roundl.c (huge): Remove variable. (__roundl): Do not force "inexact" exception. * sysdeps/ieee754/ldbl-96/s_roundl.c (huge): Remove variable. (__roundl): Do not force "inexact" exception. * math/libm-test.inc (round_test_data): Do not allow spurious "inexact" exceptions.
Diffstat (limited to 'sysdeps/ieee754/ldbl-96/s_roundl.c')
| -rw-r--r-- | sysdeps/ieee754/ldbl-96/s_roundl.c | 8 |
1 files changed, 0 insertions, 8 deletions
diff --git a/sysdeps/ieee754/ldbl-96/s_roundl.c b/sysdeps/ieee754/ldbl-96/s_roundl.c index 4f35c4847b..5a6988cd8b 100644 --- a/sysdeps/ieee754/ldbl-96/s_roundl.c +++ b/sysdeps/ieee754/ldbl-96/s_roundl.c @@ -22,9 +22,6 @@ #include <math_private.h> -static const long double huge = 1.0e4930L; - - long double __roundl (long double x) { @@ -37,7 +34,6 @@ __roundl (long double x) { if (j0 < 0) { - math_force_eval (huge + x); se &= 0x8000; i0 = i1 = 0; if (j0 == -1) @@ -53,8 +49,6 @@ __roundl (long double x) /* X is integral. */ return x; - /* Raise inexact if x != 0. */ - math_force_eval (huge + x); u_int32_t j = i0 + (0x40000000 >> j0); if (j < i0) se += 1; @@ -77,8 +71,6 @@ __roundl (long double x) /* X is integral. */ return x; - math_force_eval (huge + x); - /* Raise inexact if x != 0. */ u_int32_t j = i1 + (1 << (62 - j0)); if (j < i1) { |