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| author | Joseph Myers <josmyers@redhat.com> | 2025-05-14 10:51:46 +0000 |
|---|---|---|
| committer | Joseph Myers <josmyers@redhat.com> | 2025-05-14 10:51:46 +0000 |
| commit | 06caf53adfae0c93062edd62f83eed16ab5cec0b (patch) | |
| tree | 75282662b640f39f04d13b7ba79eb3e9fb79e5ea /sysdeps/ieee754/ldbl-opt | |
| parent | 36189c76fb9c0b281de23381ae5a462a7e102ee6 (diff) | |
| download | glibc-master.zip glibc-master.tar.gz glibc-master.tar.bz2 | |
C23 adds various <math.h> function families originally defined in TS
18661-4. Add the rootn functions, which compute the Yth root of X for
integer Y (with a domain error if Y is 0, even if X is a NaN). The
integer exponent has type long long int in C23; it was intmax_t in TS
18661-4, and as with other interfaces changed after their initial
appearance in the TS, I don't think we need to support the original
version of the interface.
As with pown and compoundn, I strongly encourage searching for worst
cases for ulps error for these implementations (necessarily
non-exhaustively, given the size of the input space). I also expect a
custom implementation for a given format could be much faster as well
as more accurate, although the implementation is simpler than those
for pown and compoundn.
This completes adding to glibc those TS 18661-4 functions (ignoring
DFP) that are included in C23. See
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118592 regarding the C23
mathematical functions (not just the TS 18661-4 ones) missing built-in
functions in GCC, where such functions might usefully be added.
Tested for x86_64 and x86, and with build-many-glibcs.py.
Diffstat (limited to 'sysdeps/ieee754/ldbl-opt')
| -rw-r--r-- | sysdeps/ieee754/ldbl-opt/Makefile | 2 | ||||
| -rw-r--r-- | sysdeps/ieee754/ldbl-opt/nldbl-rootn.c | 8 |
2 files changed, 10 insertions, 0 deletions
diff --git a/sysdeps/ieee754/ldbl-opt/Makefile b/sysdeps/ieee754/ldbl-opt/Makefile index 72369eb..c9791c5 100644 --- a/sysdeps/ieee754/ldbl-opt/Makefile +++ b/sysdeps/ieee754/ldbl-opt/Makefile @@ -181,6 +181,7 @@ libnldbl-calls = \ remainder \ remquo \ rint \ + rootn \ round \ roundeven \ rsqrt \ @@ -384,6 +385,7 @@ CFLAGS-nldbl-powr.c = -fno-builtin-powrl CFLAGS-nldbl-remainder.c = -fno-builtin-remainderl -fno-builtin-dreml CFLAGS-nldbl-remquo.c = -fno-builtin-remquol CFLAGS-nldbl-rint.c = -fno-builtin-rintl +CFLAGS-nldbl-rootn.c = -fno-builtin-rootnl CFLAGS-nldbl-round.c = -fno-builtin-roundl CFLAGS-nldbl-roundeven.c = -fno-builtin-roundevenl CFLAGS-nldbl-rsqrt.c = -fno-builtin-rsqrtl diff --git a/sysdeps/ieee754/ldbl-opt/nldbl-rootn.c b/sysdeps/ieee754/ldbl-opt/nldbl-rootn.c new file mode 100644 index 0000000..fb0d860 --- /dev/null +++ b/sysdeps/ieee754/ldbl-opt/nldbl-rootn.c @@ -0,0 +1,8 @@ +#include "nldbl-compat.h" + +double +attribute_hidden +rootnl (double x, long long int y) +{ + return rootn (x, y); +} |