[Bug target/113295] [14 Regression] SPEC 2006 416.gamess miscompares on Aarch64 when built with -Ofast -march=native -flto

2024-02-21 Thread tnfchris at gcc dot gnu.org via Gcc-bugs 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113295

--- Comment #3 from Tamar Christina  ---
I'm however able to reproduce it at -Ofast alone, no need for `-flto`

[Bug target/113295] [14 Regression] SPEC 2006 416.gamess miscompares on Aarch64 when built with -Ofast -march=native -flto

2024-02-21 Thread tnfchris at gcc dot gnu.org via Gcc-bugs 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113295

--- Comment #2 from Tamar Christina  ---
bisected to

commit g:2f46e3578d45ff060a0a329cb39d4f52878f9d5a
Author: Richard Sandiford 
Date:   Thu Dec 14 13:46:16 2023 +

aarch64: Improve handling of accumulators in early-ra

Being very simplistic, early-ra just models an allocno's live range
as a single interval.  This doesn't work well for single-register
accumulators that are updated multiple times in a loop, since in

and it still seems to be miscomparing today.

[Bug target/113295] [14 Regression] SPEC 2006 416.gamess miscompares on Aarch64 when built with -Ofast -march=native -flto

2024-02-19 Thread tnfchris at gcc dot gnu.org via Gcc-bugs 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113295

Tamar Christina  changed:

   What|Removed |Added

 Status|UNCONFIRMED |NEW
   Last reconfirmed||2024-02-19
 Ever confirmed|0   |1
   Priority|P3  |P1
 CC||tnfchris at gcc dot gnu.org

--- Comment #1 from Tamar Christina  ---
Ah, I missed this. Yeah we've seen it but didn't have time to track down untill
now.

however our CI shows it showed up between
g:ae034b9106fbdd855ec22ce221bb61a1a9a532c3 and
g:a064e4925afa1ad5f2f8c1350c4f57d631ce and
g:34d339bbd0c1f5b4ad9587e7ae8387c912cb028b is a target only change so unlikely
to be related.

bisecting.

[Bug target/113295] [14 Regression] SPEC 2006 416.gamess miscompares on Aarch64 when built with -Ofast -march=native -flto

2024-01-09 Thread pinskia at gcc dot gnu.org via Gcc-bugs 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113295

Andrew Pinski  changed:

   What|Removed |Added

Summary|SPEC 2006 416.gamess|[14 Regression] SPEC 2006
   |miscompares on Aarch64 when |416.gamess miscompares on
   |built with -Ofast   |Aarch64 when built with
   |-march=native -flto |-Ofast -march=native -flto
   Target Milestone|--- |14.0