[LV] Clarify code in isPredicatedInst (NFC) (#134251)
diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index 807136f..72dbef1 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -3236,11 +3236,9 @@
// TODO: Fold into LoopVectorizationLegality::isMaskRequired.
bool LoopVectorizationCostModel::isPredicatedInst(Instruction *I) const {
- // If predication is not needed, avoid it.
// TODO: We can use the loop-preheader as context point here and get
// context sensitive reasoning for isSafeToSpeculativelyExecute.
- if (!blockNeedsPredicationForAnyReason(I->getParent()) ||
- isSafeToSpeculativelyExecute(I) ||
+ if (isSafeToSpeculativelyExecute(I) ||
(isa<LoadInst, StoreInst, CallInst>(I) && !Legal->isMaskRequired(I)) ||
isa<BranchInst, SwitchInst, PHINode, AllocaInst>(I))
return false;
@@ -3250,6 +3248,10 @@
if (Legal->blockNeedsPredication(I->getParent()))
return true;
+ // If we're not folding the tail by masking, predication is unnecessary.
+ if (!foldTailByMasking())
+ return false;
+
// All that remain are instructions with side-effects originally executed in
// the loop unconditionally, but now execute under a tail-fold mask (only)
// having at least one active lane (the first). If the side-effects of the
