[clang] [libc] [llvm] [clang] Make __builtin_exp and __builtin_expf constexpr. (PR #199808)

[Hubert Tong via cfe-commits]

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@@ -2737,7 +2741,8 @@ static bool checkFloatingPointResult(EvalInfo &Info, const Expr *E,
   // - the expression being evaluated is not a part of global variable
   //   initializer,
   // the evaluation probably need to be rejected.
-  return true;
+  Info.FFDiag(E, diag::note_constexpr_float_arithmetic_strict);
+  return false;
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hubert-reinterpretcast wrote:

The code returns `false` with the same diagnostic regardless of the `if` condition. Also, can you check the history of the FIXME and see if it still applies?

https://github.com/llvm/llvm-project/pull/199808