https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111792
Bug ID: 111792 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. compiler Explorer: https://godbolt.org/z/7vfzPYTrn [537] % 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/14.0.0/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: ../gcc-trunk/configure --disable-bootstrap --enable-checking=yes --prefix=/local/suz-local/software/local/gcc-trunk --enable-sanitizers --enable-languages=c,c++ --disable-werror --enable-multilib Thread model: posix Supported LTO compression algorithms: zlib gcc version 14.0.0 20231013 (experimental) (GCC) [538] % [538] % gcctk -O2 small.c; ./a.out [539] % [539] % gcctk -O3 small.c [540] % ./a.out Aborted [541] % cat small.c int c, d, h, i, j, l, *n = &h; short e, f, g, *k, m; long o; short p(short p1, int q) { return q >= 32 || p1 > 5 >> q ? 1 : p1 << q; } long u(unsigned p1) { int r = 50, s, *t = &c; L: m && (*k = 0); for (d = 1; d; d--) for (s = 0; s < 3; s++) { *n = i ^ p1; *t = p1 > (unsigned)p((unsigned)(o = 4073709551615) >= p1 && 5, r); if (f) goto L; } for (; e < 1;) return j; int *b[2] = {&s, &r}; for (; l; l--) { long a[1]; for (r = 0; r < 1; r++) { h = a[0]; if (g) goto L; } } return 0; } int main() { u(6); if (c != 1) __builtin_abort(); return 0; }