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| author | Segher Boessenkool <segher@kernel.crashing.org> | 2017-02-06 20:19:49 +0100 |
|---|---|---|
| committer | Segher Boessenkool <segher@gcc.gnu.org> | 2017-02-06 20:19:49 +0100 |
| commit | 176274c9bf515f3b71f00b2be71a9ee4771b271f (patch) | |
| tree | eebb74792325dc6a931fd34554fc77bf0e7a321a /gcc/omp-expand.c | |
| parent | 2568d8a1f6d3912e53c457a1ea080050a834cf32 (diff) | |
| download | gcc-176274c9bf515f3b71f00b2be71a9ee4771b271f.zip gcc-176274c9bf515f3b71f00b2be71a9ee4771b271f.tar.gz gcc-176274c9bf515f3b71f00b2be71a9ee4771b271f.tar.bz2 | |
sched: Do not move expensive insns speculatively (PR68664)
Scheduling should never move very expensive instructions to places they
are executed more frequently. This patch fixes that, reducing the
execution time of c-ray by over 40% (I tested on a BE Power7 system).
This introduces a new target hook sched.can_speculate_insn which returns
whether the scheduler is allowed to speculate a given instruction. The
rs6000 implementation disallows all divide and square root instructions.
PR rtl-optimization/68664
* target.def (can_speculate_insn): New hook.
* doc/tm.texi.in (TARGET_SCHED_CAN_SPECULATE_INSN): New hook.
* doc/tm.texi: Regenerate.
* sched-rgn.c (can_schedule_ready_p): Use the new hook.
* config/rs6000/rs6000.c (TARGET_SCHED_CAN_SPECULATE_INSN): New macro.
(rs6000_sched_can_speculate_insn): New function.
From-SVN: r245215
Diffstat (limited to 'gcc/omp-expand.c')
0 files changed, 0 insertions, 0 deletions