https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117137
--- Comment #3 from Haochen Jiang <haochen.jiang at intel dot com> ---
>From my bisect:
5977b746db3925aaba37722f5312419d5f2968a5 is the first bad commit
commit 5977b746db3925aaba37722f5312419d5f2968a5
Author: Richard Biener <rguent...@suse.de>
Date: Tue Oct 8 09:01:01 2024 +0200
tree-optimization/117000 - elide .REDUC_IOR with compare against zero
The following adds a pattern to elide a .REDUC_IOR operation when
the result is compared against zero with a cbranch. I've resorted
to using can_compare_p since that's what RTL expansion eventually
checks - while GIMPLE allowed whole vector equality compares for long
I'll notice vector lowering won't lower unsupported ones and RTL
expansion doesn't seem to try using [u]cmp<vector-mode> optabs
(and neither x86 nor aarch64 implements those). There's cstore
but no target implements that for vector modes either.
PR tree-optimization/117000
* match.pd (.REDUC_IOR !=/== 0): New pattern.
* gimple-match-head.cc: Include memmodel.h and optabs.h.
* generic-match-head.cc: Likewise.
* gcc.target/i386/pr117000.c: New testcase.
gcc/generic-match-head.cc | 2 ++
gcc/gimple-match-head.cc | 2 ++
gcc/match.pd | 9 +++++++++
gcc/testsuite/gcc.target/i386/pr117000.c | 13 +++++++++++++
4 files changed, 26 insertions(+)
create mode 100644 gcc/testsuite/gcc.target/i386/pr117000.c
