[llvm] [InstCombine] Fold fcmp into select (PR #86482)

[via llvm-commits]

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@@ -8020,6 +8020,10 @@ Instruction *InstCombinerImpl::visitFCmpInst(FCmpInst &I) {
       if (Instruction *NV = foldOpIntoPhi(I, cast<PHINode>(LHSI)))
         return NV;
       break;
+    case Instruction::Select:
+      if (Instruction *NV = FoldOpIntoSelect(I, cast<SelectInst>(LHSI)))
+        return NV;
+      break;
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goldsteinn wrote:

IMO here, we have the argument `FoldWithMultiUse` and it would be a bit confusing if we started to surreptitiously assume it.

https://github.com/llvm/llvm-project/pull/86482