https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100810
Bug ID: 100810 Summary: wrong code at -O1 and above 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: --- [511] % 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 --enable-multilib --with-system-zlib Thread model: posix Supported LTO compression algorithms: zlib gcc version 12.0.0 20210528 (experimental) [master revision 4774807e6e5:0e2d976f72b:cd62d089f6021fd1ad4537b8182836d15b14514f] (GCC) [512] % [512] % gcctk -O0 small.c; ./a.out [513] % [513] % gcctk -O1 small.c [514] % ./a.out Aborted [515] % [515] % cat small.c int a, b = 1, c = 1, e, f = 1, g, h, j; volatile int d; static void k() { int i; h = b; if (c && a >= 0) { while (a) { i++; h--; } if (g) for (h = 0; h < 2; h++) ; if (!b) i &&d; } } static void l() { for (; j < 1; j++) if (!e && c && f) k(); } int main() { if (f) l(); if (h != 1) __builtin_abort(); return 0; }