[PATCH] D155356: [clang][Interp] Implement __builtin_nan family of functions

Tue Jul 18 12:42:56 PDT 2023

aaron.ballman added inline comments.

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Comment at: clang/test/AST/Interp/builtin-functions.cpp:44
+
+  constexpr float Nan2 = __builtin_nans([](){return "0xAE98";}()); // ref-error {{must be initialized by a constant expression}}
+}
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tbaeder wrote:
> aaron.ballman wrote:
> > Probably worth a comment here mentioning that the ref-error is a rejects-valid issue that the experimental compiler accepts correctly.
> I thought you said on Discord that the current interpreter is correct? I made the new one reject anything but string literals in https://reviews.llvm.org/D155545.
Oops, crossing streams as I just mentioned this in another review of yours in the same area.

I think I misunderstood the question on Discord when we were chatting. I was thinking the situation was more that Sema was allowing through something like `__builtin_nan(12);` and diagnosing it later during CodeGen. I think constexpr builtins should generally behave the same as regular constexpr functions the user could write.

I'm really sorry if I made extra work for you with this confusion!

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D155356/new/

https://reviews.llvm.org/D155356