[Bug rtl-optimization/104814] [10/11/12 Regression] ifcvt: Deleting live variable in IF-CASE-2
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104814
--- Comment #5 from CVS Commits ---
The master branch has been updated by Jakub Jelinek :
https://gcc.gnu.org/g:a2645cd8fb33b36d737b310e26f4c47401305c7b
commit r12-7651-ga2645cd8fb33b36d737b310e26f4c47401305c7b
Author: Jakub Jelinek
Date: Tue Mar 15 09:12:03 2022 +0100
ifcvt: Punt if not onlyjump_p for find_if_case_{1,2} [PR104814]
find_if_case_{1,2} implicitly assumes conditional jumps and rewrites them,
so if they have extra side-effects or are say asm goto, things don't work
well, either the side-effects are lost or we could ICE.
In particular, the testcase below on s390x has there a doloop instruction
that decrements a register in addition to testing it for non-zero and
conditionally jumping based on that.
The following patch fixes that by punting for !onlyjump_p case, i.e.
if there are side-effects in the jump instruction or it isn't a plain PC
setter.
Also, it assumes BB_END (test_bb) will be always non-NULL, because basic
blocks with 2 non-abnormal successor edges should always have some
instruction
at the end that determines which edge to take.
2022-03-15 Jakub Jelinek
PR rtl-optimization/104814
* ifcvt.cc (find_if_case_1, find_if_case_2): Punt if test_bb
doesn't
end with onlyjump_p. Assume BB_END (test_bb) is always non-NULL.
* gcc.c-torture/execute/pr104814.c: New test.
[Bug rtl-optimization/104814] [10/11/12 Regression] ifcvt: Deleting live variable in IF-CASE-2
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104814 Jakub Jelinek changed: What|Removed |Added Assignee|unassigned at gcc dot gnu.org |jakub at gcc dot gnu.org Last reconfirmed||2022-03-11 Status|UNCONFIRMED |ASSIGNED Ever confirmed|0 |1 --- Comment #4 from Jakub Jelinek --- Created attachment 52612 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=52612=edit gcc12-pr104814.patch Untested fix.
[Bug rtl-optimization/104814] [10/11/12 Regression] ifcvt: Deleting live variable in IF-CASE-2
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104814 Richard Biener changed: What|Removed |Added Priority|P3 |P2
[Bug rtl-optimization/104814] [10/11/12 Regression] ifcvt: Deleting live variable in IF-CASE-2
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104814
--- Comment #3 from Stefan Schulze Frielinghaus
---
Oh forgot to mention it is just: gcc -O1 t.c
Works fine with -O{0,2,3}
[Bug rtl-optimization/104814] [10/11/12 Regression] ifcvt: Deleting live variable in IF-CASE-2
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104814 Jakub Jelinek changed: What|Removed |Added CC||jakub at gcc dot gnu.org --- Comment #2 from Jakub Jelinek --- What options is this with? Which isa/tuning?
[Bug rtl-optimization/104814] [10/11/12 Regression] ifcvt: Deleting live variable in IF-CASE-2
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104814 Richard Biener changed: What|Removed |Added Target Milestone|--- |10.4
[Bug rtl-optimization/104814] [10/11/12 Regression] ifcvt: Deleting live variable in IF-CASE-2
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104814 --- Comment #1 from Stefan Schulze Frielinghaus --- Created attachment 52571 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=52571=edit dump combine
