https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104543
Bug ID: 104543 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: --- This appears to be a recent regression. [588] % 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/12.0.1/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 --enable-multilib --with-system-zlib Thread model: posix Supported LTO compression algorithms: zlib gcc version 12.0.1 20220215 (experimental) [master r12-7236-g2c3309e3d0f] (GCC) [589] % [589] % gcctk -O2 small.c; ./a.out [590] % [590] % gcctk -O3 small.c [591] % ./a.out Aborted [592] % [592] % cat small.c int a[3], b, c; int e() { if (!c) { for (b = 0; b < 3; b++) for (c = 0; c < 3; c++) a[c] ^= 1; return -1; } return 0; } int main() { e(); if (a[1] != 1) __builtin_abort(); return 0; }