https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123547
Bug ID: 123547
Summary: [16 Regression] Miscompilation of 557.xz_r with -Ofast
Product: gcc
Version: 16.0
Status: UNCONFIRMED
Keywords: needs-bisection, needs-reduction, wrong-code
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: pheeck at gcc dot gnu.org
Blocks: 26163
Target Milestone: ---
Host: x86_64-pc-linux-gnu
Target: x86_64-pc-linux-gnu
Running 557.xz_r SPEC 2017 benchmark compiled with -Ofast results in a
segfault.
Not sure when exactly this started happening but it was certainly before
r16-6654-gc10076b34d3ede and I would guess that it couldn't have been more than
2 weeks ago since I would have noticed this sooner.
Also, while this most likely is miscompilation, it could also be GCC taking
advantage of some UB in 557.xz_r or something like that. I didn't yet analyze
this enough. I'm compiling the benchmark with -std=gnu17, btw.
Referenced Bugs:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=26163
[Bug 26163] [meta-bug] missed optimization in SPEC (2k17, 2k and 2k6 and 95)
