glibc/sysdeps/ieee754
Paul Zimmermann 392b3f0971 replace tgammaf by the CORE-MATH implementation
The CORE-MATH implementation is correctly rounded (for any rounding mode).
This can be checked by exhaustive tests in a few minutes since there are
less than 2^32 values to check against for example GNU MPFR.
This patch also adds some bench values for tgammaf.

Tested on x86_64 and x86 (cfarm26).

With the initial GNU libc code it gave on an Intel(R) Core(TM) i7-8700:

      "tgammaf": {
       "": {
        "duration": 3.50188e+09,
        "iterations": 2e+07,
        "max": 602.891,
        "min": 65.1415,
        "mean": 175.094
       }
      }

With the new code:

      "tgammaf": {
       "": {
        "duration": 3.30825e+09,
        "iterations": 5e+07,
        "max": 211.592,
        "min": 32.0325,
        "mean": 66.1649
       }
      }

With the initial GNU libc code it gave on cfarm26 (i686):

  "tgammaf": {
   "": {
    "duration": 3.70505e+09,
    "iterations": 6e+06,
    "max": 2420.23,
    "min": 243.154,
    "mean": 617.509
   }
  }

With the new code:

  "tgammaf": {
   "": {
    "duration": 3.24497e+09,
    "iterations": 1.8e+07,
    "max": 1238.15,
    "min": 101.155,
    "mean": 180.276
   }
  }

Signed-off-by: Alexei Sibidanov <sibid@uvic.ca>
Signed-off-by: Paul Zimmermann <Paul.Zimmermann@inria.fr>

Changes in v2:
    - include <math.h> (fix the linknamespace failures)
    - restored original benchtests/strcoll-inputs/filelist#en_US.UTF-8 file
    - restored original wrapper code (math/w_tgammaf_compat.c),
      except for the dealing with the sign
    - removed the tgammaf/float entries in all libm-test-ulps files
    - address other comments from Joseph Myers
      (https://sourceware.org/pipermail/libc-alpha/2024-July/158736.html)

Changes in v3:
    - pass NULL argument for signgam from w_tgammaf_compat.c
    - use of math_narrow_eval
    - added more comments

Changes in v4:
    - initialize local_signgam to 0 in math/w_tgamma_template.c
    - replace sysdeps/ieee754/dbl-64/gamma_productf.c by dummy file

Changes in v5:
    - do not mention local_signgam any more in math/w_tgammaf_compat.c
    - initialize local_signgam to 1 instead of 0 in w_tgamma_template.c
      and added comment

Changes in v6:
    - pass NULL as 2nd argument of __ieee754_gammaf_r in
      w_tgammaf_compat.c, and check for NULL in e_gammaf_r.c

Changes in v7:
    - added Signed-off-by line for Alexei Sibidanov (author of the code)

Changes in v8:
    - added Signed-off-by line for Paul Zimmermann (submitted of the patch)

Changes in v9:
    - address comments from review by Adhemerval Zanella
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2024-10-11 11:12:32 +02:00
..
dbl-64 replace tgammaf by the CORE-MATH implementation 2024-10-11 11:12:32 +02:00
float128 Implement C23 logp1 2024-06-17 13:47:09 +00:00
flt-32 replace tgammaf by the CORE-MATH implementation 2024-10-11 11:12:32 +02:00
ldbl-64-128 math: Provide missing math symbols on libc.a (BZ 31781) 2024-05-23 09:36:08 -03:00
ldbl-96 Implement C23 logp1 2024-06-17 13:47:09 +00:00
ldbl-128 Implement C23 logp1 2024-06-17 13:47:09 +00:00
ldbl-128ibm Update copyright dates with scripts/update-copyrights 2024-01-01 10:53:40 -08:00
ldbl-128ibm-compat Implement C23 exp2m1, exp10m1 2024-06-17 16:31:49 +00:00
ldbl-opt Convert to autoconf 2.72 (vanilla release, no distribution patches) 2024-06-17 21:15:28 +02:00
soft-fp Update copyright dates with scripts/update-copyrights 2024-01-01 10:53:40 -08:00
ieee754.h Update copyright dates with scripts/update-copyrights 2024-01-01 10:53:40 -08:00
k_standard.c Use copysign functions not __copysign functions in glibc libm. 2018-09-27 20:04:48 +00:00
k_standardf.c Update copyright dates with scripts/update-copyrights 2024-01-01 10:53:40 -08:00
k_standardl.c Update copyright dates with scripts/update-copyrights 2024-01-01 10:53:40 -08:00
libm-alias-finite.h Update copyright dates with scripts/update-copyrights 2024-01-01 10:53:40 -08:00
Makefile Avoid -Wno-write-strings for k_standard.c. 2015-02-26 22:50:54 +00:00
s_lib_version.c Simplify math-svid-compat code. 2017-08-28 15:19:52 +00:00
s_matherr.c Obsolete matherr, _LIB_VERSION, libieee.a. 2017-08-21 17:45:10 +00:00
s_signgam.c Remove unnecessary math_private.h includes. 2018-09-28 21:53:33 +00:00