https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103873
Bug ID: 103873 Summary: wrong code at -O3 on x86_64-linux-gnu Product: gcc Version: unknown Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: zhendong.su at inf dot ethz.ch Target Milestone: --- It appears to be a recent regression. [568] % gcctk -v Using built-in specs. COLLECT_GCC=gcctk COLLECT_LTO_WRAPPER=/local/suz-local/software/local/gcc-trunk/libexec/gcc/x86_64-pc-linux-gnu/12.0.0/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: ../gcc-trunk/configure --disable-bootstrap --prefix=/local/suz-local/software/local/gcc-trunk --enable-languages=c,c++ --disable-werror --disable-multilib Thread model: posix Supported LTO compression algorithms: zlib gcc version 12.0.0 20211231 (experimental) (GCC) [569] % [569] % gcctk -O2 small.c; ./a.out [570] % [570] % gcctk -O3 small.c [571] % ./a.out Aborted [572] % [572] % cat small.c int a, b, c, d[3], e, f; int main() { if (b) goto L; for (; f < 1; f++) for (; a < 1; a++) { for (c = 0; c < 3; c++) for (e = 0; e < 3; e++) d[e] |= c; for (; b; b++) L:; } if (d[1] != 3) __builtin_abort(); return 0; }