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| author | Joseph Myers <joseph@codesourcery.com> | 2016-09-23 21:54:21 +0000 |
|---|---|---|
| committer | Joseph Myers <joseph@codesourcery.com> | 2016-09-23 21:54:21 +0000 |
| commit | bb8081f57f23a3e1b28b1b7104f24d17da9a3d82 (patch) | |
| tree | 0987589e19a174ecc1550dfc366813e6102973ef /manual/arith.texi | |
| parent | 4775578486c8ee2aa09b402eb272eb932e7e0691 (diff) | |
| download | glibc-bb8081f57f23a3e1b28b1b7104f24d17da9a3d82.tar.gz | |
Add iszero.
TS 18661-1 adds an iszero classification macro to <math.h>. This
patch implements it for glibc. There are no new underlying functions
in libm because the implementation uses fpclassify when sNaN support
is required and a direct comparison otherwise; any optimizations for
this macro should be done through adding __builtin_iszero in GCC and
using it in the header for suitable GCC versions, not through adding
other optimized inline or out-of-line versions to glibc.
Tested for x86_64 and x86.
* math/math.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (iszero): New
macro.
* math/libm-test.inc (iszero_test_data): New array.
(iszero_test): New function.
(main): Call iszero_test.
* manual/arith.texi (Floating Point Classes): Document iszero.
* manual/libm-err-tab.pl: Update comment on interfaces without
ulps tabulated.
Diffstat (limited to 'manual/arith.texi')
| -rw-r--r-- | manual/arith.texi | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/manual/arith.texi b/manual/arith.texi index bfa236a50e..58f35781bb 100644 --- a/manual/arith.texi +++ b/manual/arith.texi @@ -414,6 +414,14 @@ This macro returns a nonzero value if @var{x} is subnormal. It is from TS 18661-1:2014. @end deftypefn +@comment math.h +@comment ISO +@deftypefn {Macro} int iszero (@emph{float-type} @var{x}) +@safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}} +This macro returns a nonzero value if @var{x} is zero. It is from TS +18661-1:2014. +@end deftypefn + Another set of floating-point classification functions was provided by BSD. @Theglibc{} also supports these functions; however, we recommend that you use the ISO C99 macros in new code. Those are standard |