llvm-project

61a0653c - [VPlan] Fix first-order splices without header mask not using EVL (#146672)

[VPlan] Fix first-order splices without header mask not using EVL (#146672) This fixes a buildbot failure with EVL tail folding after #144666: https://lab.llvm.org/buildbot/#/builders/132/builds/1653 For a first-order recurrence to be correct with EVL tail folding we need to convert splices to vp splices with the EVL operand. Originally we did this by looking for users of the header mask and its users, and converting it in createEVLRecipe. However after #144666 a FOR splice might not actually use the header mask if it's based off e.g. an induction variable, and so we wouldn't pick it up in createEVLRecipe. This fixes this by converting FOR splices separately in a loop over all recipes in the plan, regardless of whether or not it uses the header mask. I think there was some conflation in createEVLRecipe between what was an optimisation and what was needed for correctness. Most of the transforms in it just exist to optimize the mask away and we should still emit correct code without them. So I've renamed it to make the separation clearer.