[llvm] [SPIRV] Fix vector bitcast check in LegalizePointerCast (PR #164997)

[Lucie Choi via llvm-commits]

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@@ -73,16 +73,23 @@ class SPIRVLegalizePointerCast : public FunctionPass {
   // Returns the loaded value.
   Value *loadVectorFromVector(IRBuilder<> &B, FixedVectorType *SourceType,
                               FixedVectorType *TargetType, Value *Source) {
-    assert(TargetType->getNumElements() <= SourceType->getNumElements());
     LoadInst *NewLoad = B.CreateLoad(SourceType, Source);
     buildAssignType(B, SourceType, NewLoad);
     Value *AssignValue = NewLoad;
     if (TargetType->getElementType() != SourceType->getElementType()) {
+      const DataLayout &DL = B.GetInsertBlock()->getModule()->getDataLayout();
+      [[maybe_unused]] TypeSize TargetTypeSize =
+          DL.getTypeSizeInBits(TargetType);
+      [[maybe_unused]] TypeSize SourceTypeSize =
+          DL.getTypeSizeInBits(SourceType);
+      assert(TargetTypeSize == SourceTypeSize);
       AssignValue = B.CreateIntrinsic(Intrinsic::spv_bitcast,
                                       {TargetType, SourceType}, {NewLoad});
       buildAssignType(B, TargetType, AssignValue);
+      return AssignValue;
     }
 
+    assert(TargetType->getNumElements() < SourceType->getNumElements());
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luciechoi wrote:

> assert(TargetType->getNumElements() < SourceType->getNumElements());

Double checking if it should be `<=`

https://github.com/llvm/llvm-project/pull/164997