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| author | Joseph Myers <joseph@codesourcery.com> | 2016-05-24 17:42:10 +0000 |
|---|---|---|
| committer | Joseph Myers <joseph@codesourcery.com> | 2016-05-24 17:42:10 +0000 |
| commit | ac2cc6f021ae4503f1d51c2379d5551a8b05812b (patch) | |
| tree | af8e7b365bcd0a728f995bed568ce0203a147164 /sysdeps/ieee754/dbl-64/s_ceil.c | |
| parent | 6901def689b5c77465d34f07822989ec67e80c1e (diff) | |
| download | glibc-ac2cc6f021ae4503f1d51c2379d5551a8b05812b.tar.gz glibc-ac2cc6f021ae4503f1d51c2379d5551a8b05812b.tar.xz glibc-ac2cc6f021ae4503f1d51c2379d5551a8b05812b.zip | |
Do not raise "inexact" from generic ceil (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 ceil functions to align them with TS 18661-1 in this regard. Note that some architecture-specific versions may still raise "inexact", so the tests are not updated and the bug is not yet fixed. Tested for x86_64, x86 and mips64. [BZ #15479] * sysdeps/ieee754/dbl-64/s_ceil.c: Do not mention "inexact" exception in comment. (huge): Remove variable. (__ceil): Do not force "inexact" exception. * sysdeps/ieee754/dbl-64/wordsize-64/s_ceil.c: Do not mention "inexact" exception in comment. (huge): Remove variable. (__ceil): Do not force "inexact" exception. * sysdeps/ieee754/flt-32/s_ceilf.c (huge): Remove variable. (__ceilf): Do not force "inexact" exception. * sysdeps/ieee754/ldbl-128/s_ceill.c: Do not mention "inexact" exception in comment. (huge): Remove variable. (__ceill): Do not force "inexact" exception.
Diffstat (limited to 'sysdeps/ieee754/dbl-64/s_ceil.c')
| -rw-r--r-- | sysdeps/ieee754/dbl-64/s_ceil.c | 9 |
1 files changed, 1 insertions, 8 deletions
diff --git a/sysdeps/ieee754/dbl-64/s_ceil.c b/sysdeps/ieee754/dbl-64/s_ceil.c index b2154b407d..c291c26f57 100644 --- a/sysdeps/ieee754/dbl-64/s_ceil.c +++ b/sysdeps/ieee754/dbl-64/s_ceil.c @@ -15,15 +15,11 @@ * Return x rounded toward -inf to integral value * Method: * Bit twiddling. - * Exception: - * Inexact flag raised if x not equal to ceil(x). */ #include <math.h> #include <math_private.h> -static const double huge = 1.0e300; - double __ceil (double x) { @@ -33,9 +29,8 @@ __ceil (double x) j0 = ((i0 >> 20) & 0x7ff) - 0x3ff; if (j0 < 20) { - if (j0 < 0) /* raise inexact if x != 0 */ + if (j0 < 0) { - math_force_eval (huge + x); /* return 0*sign(x) if |x|<1 */ if (i0 < 0) { @@ -51,7 +46,6 @@ __ceil (double x) i = (0x000fffff) >> j0; if (((i0 & i) | i1) == 0) return x; /* x is integral */ - math_force_eval (huge + x); /* raise inexact flag */ if (i0 > 0) i0 += (0x00100000) >> j0; i0 &= (~i); i1 = 0; @@ -69,7 +63,6 @@ __ceil (double x) i = ((u_int32_t) (0xffffffff)) >> (j0 - 20); if ((i1 & i) == 0) return x; /* x is integral */ - math_force_eval (huge + x); /* raise inexact flag */ if (i0 > 0) { if (j0 == 20) |