[Bug tree-optimization/71815] SLSR misses several PHI candidate cases

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71815 Bill Schmidt changed: What|Removed |Added Status|NEW |RESOLVED Resolution|---

[Bug tree-optimization/71815] SLSR misses several PHI candidate cases

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71815 --- Comment #11 from Bill Schmidt --- Author: wschmidt Date: Mon Jun 26 14:19:33 2017 New Revision: 249649 URL: https://gcc.gnu.org/viewcvs?rev=249649=gcc=rev Log: [gcc] 2016-06-26 Bill Schmidt PR

[Bug tree-optimization/71815] SLSR misses several PHI candidate cases

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71815 --- Comment #10 from Bill Schmidt --- I re-ran benchmarks today and the results that I saw before are no longer present. The patch is neutral with regard to SPEC cpu2006 performance on ppc64le. So I'll plan to have this patch reviewed.

[Bug tree-optimization/71815] SLSR misses several PHI candidate cases

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71815 --- Comment #9 from Bill Schmidt --- I'm not comfortable with the results of the patch. Overall I see a slight improvement for SPECint CPU2006 and a slightly larger degradation for SPECfp CPU2006. But there are some individual slowdowns that

[Bug tree-optimization/71815] SLSR misses several PHI candidate cases

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71815 --- Comment #8 from Bill Schmidt --- Created attachment 39085 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=39085=edit Patch under test Attaching a patch that passes regstrap. I want to do a little benchmarking before submitting it

[Bug tree-optimization/71815] SLSR misses several PHI candidate cases

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71815 --- Comment #7 from Bill Schmidt --- I have a prototype that fixes this in the obvious way and it causes both slsr-35.c and slsr-36.c to pass again without turning off code hoisting. I'll do a regstrap and then work on some benchmark testing.

[Bug tree-optimization/71815] SLSR misses several PHI candidate cases

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71815 --- Comment #6 from Bill Schmidt --- Actually, it looks like a similar problem for the unknown stride case. Again there is logic that relies on single-reached-use for determining what expressions go dead. We need to factor in expressions that

[Bug tree-optimization/71815] SLSR misses several PHI candidate cases

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71815 --- Comment #5 from Bill Schmidt --- I'll note that in the case where the stride is known (slsr-35.c), SLSR is making at least a somewhat rational decision based on cost not to strength-reduce the phi candidate. In this case the stride is a

[Bug tree-optimization/71815] SLSR misses several PHI candidate cases

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71815 Bill Schmidt changed: What|Removed |Added Status|UNCONFIRMED |NEW Last reconfirmed|

[Bug tree-optimization/71815] SLSR misses several PHI candidate cases

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71815 --- Comment #3 from Bill Schmidt --- OK. I'm busy wrapping up some things before a vacation, but I'll plan to look into this when I get back.

[Bug tree-optimization/71815] SLSR misses several PHI candidate cases

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71815 --- Comment #2 from rguenther at suse dot de --- On Fri, 8 Jul 2016, wschmidt at gcc dot gnu.org wrote: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71815 > > --- Comment #1 from Bill Schmidt --- > Interesting. How do we enable/disable

[Bug tree-optimization/71815] SLSR misses several PHI candidate cases

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71815 --- Comment #1 from Bill Schmidt --- Interesting. How do we enable/disable code hoisting? I don't see a documented option for this.