https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115966
Bug ID: 115966
Summary: [15 Regression] Miscompilation of 403.gcc with -Ofast
-march=native on x86_64
Product: gcc
Version: 15.0
Status: UNCONFIRMED
Keywords: needs-bisection, wrong-code
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: pheeck at gcc dot gnu.org
Blocks: 26163
Target Milestone: ---
Host: x86_64-linux
Target: x86_64-linux
Compiling the 403.gcc CPU SPEC 2006 benchmark with -g -Ofast -march=native
-fpermissive (403.gcc no longer compiles without -fpermissive) on an x86_64
machine results in a miscompilation. Here is what the benchmark reports:
*** Miscompare of scilab.s; for details see
/home/gcc/buildworker/source/cpu2006/benchspec/CPU2006/403.gcc/run/run_peak_ref_amd64-m64-mine.0000/scilab.s.mis
157474: .long 1764174565
.long 1248582442
^
157475: .long 1072684140
.long 1072430610
^
157476: .long 103477976
.long 3882853149
^
157477: .long 1072638526
.long 1072384995
^
157478: .long 2763002310
.long 3786780864
^
157479: .long 1072546777
.long 1072746777
^
157484: .long 579723672
.long 1095315795
^
157485: .long 1072020921
.long 1072274451
^
157486: .long 1075822880
.long 1120461514
^
157487: .long 1071776283
.long 1071400834
^
I've seen this on AMD Zen4, Zen3 and Zen2 machines and on an Intel Ice Lake
machine.
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)
