[clang] [HLSL][SPIRV] Add convergence tokens to entry point wrapper (PR #112757)

[Steven Perron via cfe-commits]

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@@ -469,14 +480,21 @@ void CGHLSLRuntime::generateGlobalCtorDtorCalls() {
   for (auto &F : M.functions()) {
     if (!F.hasFnAttribute("hlsl.shader"))
       continue;
-    IRBuilder<> B(&F.getEntryBlock(), F.getEntryBlock().begin());
+    auto* Token = getConvergenceToken(F.getEntryBlock());
+    Instruction* IP = Token ? Token : &*F.getEntryBlock().begin();
+    IRBuilder<> B(IP);
+    std::vector<OperandBundleDef> OB;
+    if (Token) {
+      llvm::Value *bundleArgs[] = {Token};
+      OB.emplace_back("convergencectrl", bundleArgs);
+    }
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s-perron wrote:

I cannot test this code yet. Any path that I know of that would exercise this code will fail because we cannot translate HLSL types to SPIR-V types yet.

However, I do have an initial implementation for that in https://github.com/s-perron/llvm-project/tree/spirv_hlsl_type which showes this works.

https://github.com/llvm/llvm-project/pull/112757