[llvm] [NFCI][IR] Add optional DataLayout argument to zero and null value related APIs (PR #183208)

[Nikita Popov via llvm-commits]

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@@ -52,7 +53,10 @@ class Constant : public User {
   Constant(const Constant &) = delete;
 
   /// Return true if this is the value that would be returned by getNullValue.
-  LLVM_ABI bool isNullValue() const;
+  LLVM_ABI bool isNullValue(const DataLayout *DL = nullptr) const;
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nikic wrote:

Why does isNullValue() need the DataLayout argument as well? Wouldn't that always be represented by ConstantPointerNull?

https://github.com/llvm/llvm-project/pull/183208