Revert "[mlir] ArithToLLVM: fix memref bitcast lowering" (llvm#126895)

Reverts llvm#125148

bot failures

mlir/lib/Conversion/ArithToLLVM/ArithToLLVM.cpp

@@ -54,25 +54,6 @@ struct ConstrainedVectorConvertToLLVMPattern
   }
 };
 
-/// 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;
-
-  LogicalResult
-  matchAndRewrite(arith::BitcastOp op, OpAdaptor adaptor,
-                  ConversionPatternRewriter &rewriter) const final {
-    Value src = adaptor.getIn();
-    Type resultType = getTypeConverter()->convertType(op.getType());
-    if (src.getType() != resultType)
-      return rewriter.notifyMatchFailure(op, "Types are different");
-
-    rewriter.replaceOp(op, src);
-    return success();
-  }
-};
-
 //===----------------------------------------------------------------------===//
 // Straightforward Op Lowerings
 //===----------------------------------------------------------------------===//
@@ -543,9 +524,6 @@ void mlir::arith::registerConvertArithToLLVMInterface(
 
 void mlir::arith::populateArithToLLVMConversionPatterns(
     const LLVMTypeConverter &converter, RewritePatternSet &patterns) {
-
-  patterns.add<IdentityBitcastLowering>(converter, patterns.getContext());
-
   // clang-format off
   patterns.add<
     AddFOpLowering,

mlir/lib/Conversion/LLVMCommon/VectorPattern.cpp

@@ -103,14 +103,6 @@ LogicalResult LLVM::detail::handleMultidimensionalVectors(
   return success();
 }
 
-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, LLVM::LLVMPointerType, VectorType,
-             IntegerType, FloatType>(type) &&
-         LLVM::isCompatibleType(type);
-}
-
 LogicalResult LLVM::detail::vectorOneToOneRewrite(
     Operation *op, StringRef targetOp, ValueRange operands,
     ArrayRef<NamedAttribute> targetAttrs,
@@ -119,7 +111,7 @@ LogicalResult LLVM::detail::vectorOneToOneRewrite(
   assert(!operands.empty());
 
   // Cannot convert ops if their operands are not of LLVM type.
-  if (!llvm::all_of(operands.getTypes(), isVectorCompatibleType))
+  if (!llvm::all_of(operands.getTypes(), isCompatibleType))
     return failure();
 
   auto llvmNDVectorTy = operands[0].getType();

mlir/test/Conversion/ArithToLLVM/arith-to-llvm.mlir

@@ -727,15 +727,3 @@ func.func @ops_supporting_overflow(%arg0: i64, %arg1: i64) {
   %3 = arith.shli %arg0, %arg1 overflow<nsw, nuw> : i64
   return
 }
-
-// -----
-
-// CHECK-LABEL: func @memref_bitcast
-//  CHECK-SAME:   (%[[ARG:.*]]: memref<?xi16>)
-//       CHECK:   %[[V1:.*]] = builtin.unrealized_conversion_cast %[[ARG]] : memref<?xi16> to !llvm.struct<(ptr, ptr, i64, array<1 x i64>, array<1 x i64>)>
-//       CHECK:   %[[V2:.*]] = builtin.unrealized_conversion_cast %[[V1]] : !llvm.struct<(ptr, ptr, i64, array<1 x i64>, array<1 x i64>)> to memref<?xbf16>
-//       CHECK:   return %[[V2]]
-func.func @memref_bitcast(%1: memref<?xi16>) -> memref<?xbf16> {
-  %2 = arith.bitcast %1 : memref<?xi16> to memref<?xbf16>
-  func.return %2 : memref<?xbf16>
-}