367df18050
It can happen that after widening of the IV, flattening may not be possible, e.g. when it is deemed unprofitable. We were not properly checking this, which resulted in flattening being applied when it shouldn't, also leading to incorrect results (miscompilation). This should fix PR51980 (https://bugs.llvm.org/show_bug.cgi?id=51980) Differential Revision: https://reviews.llvm.org/D110712