Support SM6.6 keyword "WaveSize" (#3871)

Resolves an issue #3385

Shader Model 6.6 added a new keyowrd, "WaveSize". See the following link
for more details:
  https://microsoft.github.io/DirectX-Specs/d3d/HLSL_SM_6_6_WaveSize.html

Co-authored-by: Yong He <yonghe@outlook.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/source/slang/slang-emit-hlsl.cpp b/source/slang/slang-emit-hlsl.cpp
index 92866f9c4..37411c93e 100644
--- a/source/slang/slang-emit-hlsl.cpp
+++ b/source/slang/slang-emit-hlsl.cpp
@@ -351,10 +351,22 @@ void HLSLSourceEmitter::emitEntryPointAttributesImpl(IRFunc* irFunc, IREntryPoin
             m_writer->emit(")]\n");
         };
 
+    auto emitWaveSizeAttribute = [&]()
+        {
+            Int waveSize;
+            if (getComputeWaveSize(irFunc, &waveSize))
+            {
+                m_writer->emit("[WaveSize(");
+                m_writer->emit(waveSize);
+                m_writer->emit(")]\n");
+            }
+        };
+
     switch (stage)
     {
         case Stage::Compute:
         {
+            emitWaveSizeAttribute();
             emitNumThreadsAttribute();
         }
         break;