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authorAdhemerval Zanella <adhemerval.zanella@linaro.org>2017-12-05 15:27:03 -0200
committerAdhemerval Zanella <adhemerval.zanella@linaro.org>2017-12-05 16:27:44 -0200
commit94d80dfc7349b3545942fbbb1d5ff05f354afdf8 (patch)
tree07984816a08b1592f3a765cc211752fd2a7d3598 /elf/ifuncmain1.c
parent00d54af7c86cdcabc18c00619c229f49f4978610 (diff)
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math: Use sign as double for reduced case in sinf
This patch avoid an extra floating point to integer conversion in
reduced internal function for generic sinf by defining the sign as
double instead of integers.

There is no much difference on Haswell with GCC 7.2.1:

           Before        After
min          9.11        9.108
mean       21.982      21.9224

However H.J. Lu reported gains on Skylake:

Before:

  "sinf": {
   "": {
    "duration": 3.4044e+10,
    "iterations": 1.9942e+09,
    "max": 141.106,
    "min": 7.704,
    "mean": 17.0715
   }
  }

After:

  "sinf": {
   "": {
    "duration": 3.40665e+10,
    "iterations": 2.03199e+09,
    "max": 95.994,
    "min": 7.704,
    "mean": 16.765
   }
  }

Checked on x86_64-linux-gnu.

	* sysdeps/ieee754/flt-32/s_sinf.c (ones): Define as double.
	(reduced): Use ones as double instead of integer.
Diffstat (limited to 'elf/ifuncmain1.c')
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