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| author | Paul A. Clarke <pc@us.ibm.com> | 2019-06-20 11:57:18 -0500 |
|---|---|---|
| committer | Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com> | 2019-06-30 08:40:44 -0300 |
| commit | 3db85a9814784a74536a1f0e7b7ddbfef7dc84bb (patch) | |
| tree | 38c7cbbeae1d517b1fd54e723bf55e0d8887abe1 /ChangeLog | |
| parent | d064591266634a8ff55b645181167b8626c793c9 (diff) | |
| download | glibc-3db85a9814784a74536a1f0e7b7ddbfef7dc84bb.zip glibc-3db85a9814784a74536a1f0e7b7ddbfef7dc84bb.tar.gz glibc-3db85a9814784a74536a1f0e7b7ddbfef7dc84bb.tar.bz2 | |
powerpc: Use faster means to access FPSCR when possible in some cases
Using 'mffs' instruction to read the Floating Point Status Control Register
(FPSCR) can force a processor flush in some cases, with undesirable
performance impact. If the values of the bits in the FPSCR which force the
flush are not needed, an instruction that is new to POWER9 (ISA version 3.0),
'mffsl' can be used instead.
Cases included: get_rounding_mode, fegetround, fegetmode, fegetexcept.
* sysdeps/powerpc/bits/fenvinline.h (__fegetround): Use
__fegetround_ISA300() or __fegetround_ISA2() as appropriate.
(__fegetround_ISA300) New.
(__fegetround_ISA2) New.
* sysdeps/powerpc/fpu_control.h (IS_ISA300): New.
(_FPU_MFFS): Move implementation...
(_FPU_GETCW): Here.
(_FPU_MFFSL): Move implementation....
(_FPU_GET_RC_ISA300): Here. New.
(_FPU_GET_RC): Use _FPU_GET_RC_ISA300() or _FPU_GETCW() as appropriate.
* sysdeps/powerpc/fpu/fenv_libc.h (fegetenv_status_ISA300): New.
(fegetenv_status): New.
* sysdeps/powerpc/fpu/fegetmode.c (fegetmode): Use fegetenv_status()
instead of fegetenv_register().
* sysdeps/powerpc/fpu/fegetexcept.c (__fegetexcept): Likewise.
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
Diffstat (limited to 'ChangeLog')
| -rw-r--r-- | ChangeLog | 18 |
1 files changed, 18 insertions, 0 deletions
@@ -1,3 +1,21 @@ +2019-06-30 Paul A. Clarke <pc@us.ibm.com> + + * sysdeps/powerpc/bits/fenvinline.h (__fegetround): Use + __fegetround_ISA300() or __fegetround_ISA2() as appropriate. + (__fegetround_ISA300) New. + (__fegetround_ISA2) New. + * sysdeps/powerpc/fpu_control.h (IS_ISA300): New. + (_FPU_MFFS): Move implementation... + (_FPU_GETCW): Here. + (_FPU_MFFSL): Move implementation.... + (_FPU_GET_RC_ISA300): Here. New. + (_FPU_GET_RC): Use _FPU_GET_RC_ISA300() or _FPU_GETCW() as appropriate. + * sysdeps/powerpc/fpu/fenv_libc.h (fegetenv_status_ISA300): New. + (fegetenv_status): New. + * sysdeps/powerpc/fpu/fegetmode.c (fegetmode): Use fegetenv_status() + instead of fegetenv_register(). + * sysdeps/powerpc/fpu/fegetexcept.c (__fegetexcept): Likewise. + 2019-06-28 Wilco Dijkstra <wdijkstr@arm.com> * benchtests/bench-math-inlines.c: Increase iterations. |