[PATCH] D126857: [HLSL] Add WaveActiveCountBits as Langugage builtin function for HLSL

[Anastasia Stulova via Phabricator via cfe-commits]

Anastasia added inline comments.


================
Comment at: clang/include/clang/Basic/Builtins.def:1697
+// HLSL
+LANGBUILTIN(WaveActiveCountBits, "Uib", "nc", HLSL_LANG)
+
----------------
FYI we most of time try to add a builtin name using a reserved identifier which is not part of the language standard (mostly prefixed by `__`). Then we add regular function that just calls the clang builtins. This way provides more flexibility to the implementers. However you might not need this... in which case using original name avoids an extra call.


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Comment at: clang/test/SemaHLSL/Wave.hlsl:7
+uint foo(bool b) {
+    return WaveActiveCountBits(b);
+}
----------------
if you are planning to add a proper CodeGen test later then here it might be sufficient to have a `-verify` test and check that the builtin is accepted with the right arguments... you might want to add a test checking that a diagnostic is provided when the arguments are wrong... although this is not strictly necessary as we already test clang builtins quite extensively.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D126857/new/

https://reviews.llvm.org/D126857