[Mlir-commits] [mlir] [mlir][ptr] Add constantop convertion (PR #204846)

[Fabian Mora]

================
@@ -370,6 +382,33 @@ LogicalResult TypeOffsetOpConversion::matchAndRewrite(
   return success();
 }
 
+//===----------------------------------------------------------------------===//
+// ConstantOpConversion
+//===----------------------------------------------------------------------===//
+
+LogicalResult ConstantOpConversion::matchAndRewrite(
+    ptr::ConstantOp op, OpAdaptor adaptor,
+    ConversionPatternRewriter &rewriter) const {
+  TypedAttr value = op.getValue();
+  Type resultType = getTypeConverter()->convertType(op.getType());
+  if (!resultType)
+    return rewriter.notifyMatchFailure(op, "Couldn't convert the result type");
+
+  if (isa<ptr::NullAttr>(value)) {
+    rewriter.replaceOpWithNewOp<LLVM::ZeroOp>(op, resultType);
+  } else if (auto addrAttr = dyn_cast<ptr::AddressAttr>(value)) {
+    Type intType = rewriter.getIntegerType(addrAttr.getValue().getBitWidth());
+    Value intConst = LLVM::ConstantOp::create(rewriter, op.getLoc(), intType,
+                                              addrAttr.getValue());
+    rewriter.replaceOpWithNewOp<LLVM::IntToPtrOp>(op, resultType, intConst);
+  } else {
+    return rewriter.notifyMatchFailure(
+        op, "unsupported value attribute kind: " +
+                value.getAbstractAttribute().getName());
+  }
+  return success();
+}
----------------
fabianmcg wrote:

Always prefer code that returns early and decreases indentation, it makes it more readable.

```suggestion
  if (isa<ptr::NullAttr>(value)) {
    rewriter.replaceOpWithNewOp<LLVM::ZeroOp>(op, resultType);
    return success();
  } 
  auto addrAttr = dyn_cast<ptr::AddressAttr>(value);
  // Early-exit if unknown attribute.
  if (!addrAttr) {
    return rewriter.notifyMatchFailure(
        op, "unsupported value attribute kind: " +
                value.getAbstractAttribute().getName());
  }
  Type intType = rewriter.getIntegerType(addrAttr.getValue().getBitWidth());
   Value intConst = LLVM::ConstantOp::create(rewriter, op.getLoc(), intType,
                                            addrAttr.getValue());
  rewriter.replaceOpWithNewOp<LLVM::IntToPtrOp>(op, resultType, intConst);
  return success();
}
```

https://github.com/llvm/llvm-project/pull/204846