[llvm] [LLVM][InstSimplify] Refactor simplifyBinaryIntrinsic to remove Call operand. (PR #196309)

[Nikita Popov via llvm-commits]

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@@ -121,8 +121,10 @@ class LLVM_ABI InstSimplifyFolder final : public IRBuilderFolder {
 
   Value *FoldBinaryIntrinsic(Intrinsic::ID ID, Value *LHS, Value *RHS, Type *Ty,
                              Instruction *FMFSource = nullptr) const override {
-    return simplifyBinaryIntrinsic(ID, Ty, LHS, RHS, SQ,
-                                   dyn_cast_if_present<CallBase>(FMFSource));
+    FastMathFlags FMF;
+    if (auto *FPMO = dyn_cast_if_present<FPMathOperator>(FMFSource))
+      FMF = FPMO->getFastMathFlags();
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nikic wrote:

It looks like this FMFSource argument is actually dead code, the only user passes null: https://github.com/llvm/llvm-project/blob/02c8eb80ae0d5bd841c81b5439cee197b29fe4fc/llvm/lib/IR/IRBuilder.cpp#L924-L925

This FMFSource argument should really just be an FMF argument as well and use `FMFSource.get(FMF)` as the value...

https://github.com/llvm/llvm-project/pull/196309