[HLSL] generate hlsl.wavesize attribute

[python3kgae]

Generate function attribute hlsl.wavesize from [WaveSize].

For #70118

[llvmbot]

@llvm/pr-subscribers-clang

@llvm/pr-subscribers-hlsl

Author: Xiang Li (python3kgae)

Changes

Generate function attribute hlsl.wavesize from [WaveSize].

For #70118

---

Full diff: https://github.com/llvm/llvm-project/pull/107176.diff

2 Files Affected:

• (modified) clang/lib/CodeGen/CGHLSLRuntime.cpp (+7)
• (added) clang/test/CodeGenHLSL/wavesize.hlsl (+25)

diff --git a/clang/lib/CodeGen/CGHLSLRuntime.cpp b/clang/lib/CodeGen/CGHLSLRuntime.cpp
index 4bd7b6ba58de0d..28ff1153c8e1e3 100644
--- a/clang/lib/CodeGen/CGHLSLRuntime.cpp
+++ b/clang/lib/CodeGen/CGHLSLRuntime.cpp
@@ -337,6 +337,13 @@ void clang::CodeGen::CGHLSLRuntime::setHLSLEntryAttributes(
                 NumThreadsAttr->getZ());
     Fn->addFnAttr(NumThreadsKindStr, NumThreadsStr);
   }
+  if (HLSLWaveSizeAttr *WaveSizeAttr = FD->getAttr<HLSLWaveSizeAttr>()) {
+    const StringRef WaveSizeKindStr = "hlsl.wavesize";
+    std::string WaveSizeStr =
+        formatv("{0},{1},{2}", WaveSizeAttr->getMin(), WaveSizeAttr->getMax(),
+                WaveSizeAttr->getPreferred());
+    Fn->addFnAttr(WaveSizeKindStr, WaveSizeStr);
+  }
 }
 
 static Value *buildVectorInput(IRBuilder<> &B, Function *F, llvm::Type *Ty) {
diff --git a/clang/test/CodeGenHLSL/wavesize.hlsl b/clang/test/CodeGenHLSL/wavesize.hlsl
new file mode 100644
index 00000000000000..ae4b2f17c543e0
--- /dev/null
+++ b/clang/test/CodeGenHLSL/wavesize.hlsl
@@ -0,0 +1,25 @@
+// RUN: %clang_cc1 -std=hlsl2021 -finclude-default-header -x hlsl -triple \
+// RUN:   dxil-pc-shadermodel6.6-compute %s -DSM66 -hlsl-entry foo \
+// RUN:   -emit-llvm -disable-llvm-passes -o - | FileCheck %s
+
+// RUN: %clang_cc1 -std=hlsl2021 -finclude-default-header -x hlsl -triple \
+// RUN:   dxil-pc-shadermodel6.8-compute %s -hlsl-entry foo \
+// RUN:   -emit-llvm -disable-llvm-passes -o - | FileCheck %s --check-prefix=CHECK-SM68
+
+
+// Make sure wavesize attribute get correct value for sm66 and sm68.
+// CHECK:define void @foo()
+// CHECK:"hlsl.wavesize"="8,0,0"
+
+// CHECK-SM68:define void @foo()
+// CHECK-SM68:"hlsl.wavesize"="8,128,64"
+
+[numthreads(16,8,1)]
+#ifdef SM66
+[WaveSize(8)]
+#else
+[WaveSize(8, 128, 64)]
+#endif
+void foo() {
+
+}