https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101173
Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Target Milestone|--- |9.5 Keywords| |wrong-code CC| |amker at gcc dot gnu.org Summary|wrong code at -O3 on |[9/10/11/12 Regression] |x86_64-linux-gnu |wrong code at -O3 on | |x86_64-linux-gnu Ever confirmed|0 |1 Version|unknown |12.0 Known to work| |7.5.0 Priority|P3 |P2 Last reconfirmed| |2021-06-23 Status|UNCONFIRMED |NEW Known to fail| |8.5.0 --- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> --- Confirmed. int a[6][9]; int c; int main() { a[1][3] = 8; for (int b = 1; b <= 5; b++) for (int d = 0; d <= 5; d++) for (c = 0; c <= 5; c++) a[b][c] = a[b][c + 2] & 216; for (int e = 0; e < 6; e++) for (int f = 0; f < 9; f++) if (a[e][f] != 0) __builtin_abort (); return 0; } Fails with -O -floop-interchange already.