https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70354
--- Comment #9 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Simpler testcase: unsigned long long a[64], b[64]; __attribute__((noinline, noclone)) void foo (void) { int i; for (i = 0; i < 64; i++) a[i] <<= (b[i] - 0x1200000000ULL); } int main () { int i; for (i = 0; i < 64; i++) { a[i] = 0x1234ULL; b[i] = 0x1200000000ULL + (i % 54); } foo (); for (i = 0; i < 64; i++) if (a[i] != (0x1234ULL << (i % 54))) __builtin_abort (); return 0; }