[llvm] [ConstantFold] Fold `log1p` and `log1pf` when the input parameter is a constant value. (PR #112113)

[via llvm-commits]

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@@ -2394,6 +2395,11 @@ static Constant *ConstantFoldScalarCall1(StringRef Name,
       if (!APF.isZero() && TLI->has(Func))
         return ConstantFoldFP(logb, APF, Ty);
       break;
+    case LibFunc_log1p:
+    case LibFunc_log1pf:
+      if (APF > APFloat(APF.getSemantics(), "-1") && TLI->has(Func))
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c8ef wrote:

Using `-1` directly seems to pick a different constructor and not achieve the intended behavior. Using `-1.0` will pick a deleted constructor, so I opted to use `"-1"` here.

https://github.com/llvm/llvm-project/pull/112113