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Author: Hardcode84

mlir/lib/Conversion/ArithToLLVM/ArithToLLVM.cpp

@@ -54,7 +54,8 @@ struct ConstrainedVectorConvertToLLVMPattern
   }
 };
 
-/// No-op bitcast.
+/// No-op bitcast. Propagate type input arg if converted source and dest types
+/// are the same.
 struct IdentityBitcastLowering final
     : public OpConversionPattern<arith::BitcastOp> {
   using OpConversionPattern::OpConversionPattern;
@@ -63,7 +64,8 @@ struct IdentityBitcastLowering final
   matchAndRewrite(arith::BitcastOp op, OpAdaptor adaptor,
                   ConversionPatternRewriter &rewriter) const final {
     Value src = adaptor.getIn();
-    if (src.getType() != getTypeConverter()->convertType(op.getType()))
+    Type resultType = getTypeConverter()->convertType(op.getType());
+    if (src.getType() != resultType)
       return rewriter.notifyMatchFailure(op, "Types are different");
 
     rewriter.replaceOp(op, src);

mlir/lib/Conversion/LLVMCommon/VectorPattern.cpp

@@ -104,6 +104,8 @@ LogicalResult LLVM::detail::handleMultidimensionalVectors(
 }
 
 static bool isVectorCompatibleType(Type type) {
+  // Limit `vectorOneToOneRewrite` to scalar and vector types (and to
+  // `LLVM::LLVMArrayType` which have a special handling).
   return isa<LLVM::LLVMArrayType, VectorType, IntegerType, FloatType>(type) &&
          LLVM::isCompatibleType(type);
 }