http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52865
Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Last reconfirmed| |2013-01-16 Ever Confirmed|0 |1 --- Comment #8 from Richard Biener <rguenth at gcc dot gnu.org> 2013-01-16 10:04:27 UTC --- In another bug I stated that while (1) { ... if (countm1.0 == 0) goto L.2; countm1.0 = countm1.0 + 4294967295; } L.2:; is bad for the vectorizer (the non-empty latch block). You instead want GFortran to emit while (1) { ... tem = countm1.0 countm1.0 = countm1.0 + 4294967295; if (tem == 0) goto L.2; } L.2:; where hopefully the addition does not overflow ... That said, somewhat lessening the restriction on empty latch blocks is certainly possible (IV increments should be fine), but it might be not as trivial as it looks.