[PATCH] D152351: [clang] Add __builtin_isfpclass

[Aaron Ballman via Phabricator via cfe-commits]

aaron.ballman added a comment.

In D152351#4402785 <https://reviews.llvm.org/D152351#4402785>, @arsenm wrote:

> Also should get mentioned in the builtin docs and release notes

+1, also, should there be named constants for the mask values?



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Comment at: clang/include/clang/Basic/Builtins.def:491
 BUILTIN(__builtin_isnormal,   "i.", "FnctE")
+BUILTIN(__builtin_isfpclass,  "iCi.", "nctE")
 
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`E` in the third arguments means it can be constant evaluated in the frontend, but I don't see any code or tests for that.


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Comment at: clang/lib/Sema/SemaChecking.cpp:2776-2778
+  case Builtin::BI__builtin_isfpclass:
+    if (SemaBuiltinConstantArgRange(TheCall, 0, 0, llvm::fcAllFlags))
+      return ExprError();
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Do we diagnose if the second argument to the call isn't a floating-point value? e.g., `__builtin_isfpclass(0x1, some_struct)`


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Comment at: clang/test/Sema/builtins.c:384
+  return __builtin_isfpclass(1024, x); // expected-error {{argument value 1024 is outside the valid range [0, 1023]}}
+}
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arsenm wrote:
> What happens if you pass complex?
What happens if you pass a non-float second argument, or a bit mask that doesn't match any of the valid values, or a bit mask that matches multiple valid values?


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