[llvm] [IR] Store fast-math flags in subclasses of Instruction (PR #191190)

[Alexis Engelke via llvm-commits]

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@@ -201,6 +201,9 @@ class FPMathOperator : public Operator {
 private:
   friend class Instruction;
 
+  unsigned short &getFMFValue();
+  unsigned short getFMFValue() const;
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aengelke wrote:

How is this different from getFastMathFlags? Could be called getFastMathFlagsImpl or similar? Also these should be LLVM_READONLY.

https://github.com/llvm/llvm-project/pull/191190