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Author: XChy

llvm/lib/Transforms/Vectorize/VectorCombine.cpp

@@ -872,11 +872,13 @@ bool VectorCombine::foldBitOpOfCastops(Instruction &I) {
 
   auto *SrcTy = LHSSrc->getType();
   auto *DstTy = I.getType();
-  // Only handle vector types with integer elements if the cast is not bitcast
+  // Bitcasts can handle scalar/vector mixes, such as i16 -> <16 x i1>.
+  // Other casts only handle vector types with integer elements.
   if (CastOpcode != Instruction::BitCast &&
       (!isa<FixedVectorType>(SrcTy) || !isa<FixedVectorType>(DstTy)))
     return false;
 
+  // Only integer scalar/vector values are legal for bitwise logic operations.
   if (!SrcTy->getScalarType()->isIntegerTy() ||
       !DstTy->getScalarType()->isIntegerTy())
     return false;