https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102131
Hongtao.liu <crazylht at gmail dot com> changed:
What |Removed |Added
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CC| |crazylht at gmail dot com
--- Comment #13 from Hongtao.liu <crazylht at gmail dot com> ---
(In reply to CVS Commits from comment #11)
> The master branch has been updated by Richard Biener <rgue...@gcc.gnu.org>:
>
> https://gcc.gnu.org/g:f1af8528d34418bc874ae9d993ee0dc3559972d2
>
> commit r12-6844-gf1af8528d34418bc874ae9d993ee0dc3559972d2
> Author: Richard Biener <rguent...@suse.de>
> Date: Mon Jan 24 11:50:06 2022 +0100
>
> tree-optimization/102131 - fix niter analysis wrt overflow
>
> This fixes the overflow issues seen with analyzing
> BASE0 + STEP0 cmp BASE1 + STEP1 as BASE0 + STEP0 - STEP1 cmp BASE1
> by following the logic we have when simplifying comparisons.
>
> 2022-01-24 Richard Biener <rguent...@suse.de>
> Jiufu Guo <guoji...@linux.ibm.com>
>
> PR tree-optimization/100740
> PR tree-optimization/101508
> PR tree-optimization/101972
> PR tree-optimization/102131
> * tree-ssa-loop-niter.cc (number_of_iterations_cond): Properly
> constrain BASE0 + STEP0 cmp BASE1 + STEP1 to
> BASE0 + STEP0 - STEP1 cmp BASE1 transform.
>
> * gcc.dg/torture/pr100740.c: New testcase.
> * gcc.dg/torture/pr101508.c: Likewise.
> * gcc.dg/torture/pr101972.c: Likewise.
> * gcc.dg/torture/pr102131-1.c: Likewise.
> * gcc.dg/torture/pr102131-2.c: Likewise.
> * gcc.dg/torture/pr102131-3.c: Likewise.
> * gcc.dg/torture/pr102131-4.c: Likewise.
It regresses
https://gcc.gnu.org/pipermail/gcc-regression/2022-January/076279.html
