[clang] [llvm] [clang][HLSL][SPRI-V] Add convergence intrinsics (PR #80680)

[Chris B via cfe-commits]

Nathan =?utf-8?q?Gauër?= <brioche at google.com>,
Nathan =?utf-8?q?Gauër?= <brioche at google.com>,
Nathan =?utf-8?q?Gauër?= <brioche at google.com>
Message-ID:
In-Reply-To: <llvm.org/llvm/llvm-project/pull/80680 at github.com>


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@@ -1297,5 +1297,10 @@ _HLSL_AVAILABILITY(shadermodel, 6.0)
 _HLSL_BUILTIN_ALIAS(__builtin_hlsl_wave_active_count_bits)
 uint WaveActiveCountBits(bool Val);
 
+/// \brief Returns the index of the current lane within the current wave.
+_HLSL_AVAILABILITY(shadermodel, 6.0)
+_HLSL_BUILTIN_ALIAS(__builtin_hlsl_wave_get_lane_index)
+uint WaveGetLaneIndex();
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llvm-beanz wrote:

We should probably also apply `__attribute__((convergent))` to this function declaration. I know we didn't do that on the `WaveActiveCountBits` declaration, but we also didn't properly implement codegen for that.

https://github.com/llvm/llvm-project/pull/80680