[PATCH] D130642: [GlobalISel] Handle IntToPtr constants in dbg.value

[Felipe de Azevedo Piovezan via Phabricator via llvm-commits]

fdeazeve added inline comments.


================
Comment at: llvm/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp:103
+      if (CE->getOpcode() == Instruction::IntToPtr)
+        return cast<const Constant>(CE->getOperand(0));
+    return &C;
----------------
nikic wrote:
> What's the `cast<const Constant>()` for?
This was done to drive the lambda return type deduction to `const Constant*`, which is the type of `&C`.

I thought `getOperand` would return a `Value`, but now that you mentioned it, I see that I was wrong, it already returns a `Constant`.

So I think this code could have been rewritten with an explicit return type of the lambda and the cast removed?

```cpp
auto *NumericConstant = [&] () -> const Constant* {
    if (const auto *CE = dyn_cast<ConstantExpr>(&C))
      if (CE->getOpcode() == Instruction::IntToPtr)
        return CE->getOperand(0);
    return &C;
  }();
```


Repository:
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https://reviews.llvm.org/D130642