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

[Nathan Gauër via cfe-commits]

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@@ -1130,8 +1130,96 @@ struct BitTest {
 
   static BitTest decodeBitTestBuiltin(unsigned BuiltinID);
 };
+
+// Returns the first convergence entry/loop/anchor instruction found in |BB|.
+// std::nullopt otherwise.
+std::optional<llvm::IntrinsicInst *> getConvergenceToken(llvm::BasicBlock *BB) {
+  for (auto &I : *BB) {
+    auto *II = dyn_cast<llvm::IntrinsicInst>(&I);
+    if (II && isConvergenceControlIntrinsic(II->getIntrinsicID()))
+      return II;
+  }
+  return std::nullopt;
+}
+
 } // namespace
 
+llvm::CallBase *
+CodeGenFunction::AddConvergenceControlAttr(llvm::CallBase *Input,
+                                           llvm::Value *ParentToken) {
+  llvm::Value *bundleArgs[] = {ParentToken};
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Keenuts wrote:

well, no... tried, and there is an overload which takes either an ArrayRef of a vector, so the inline array will cause an ambiguity :/

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