[llvm] [IR] Add CallBr intrinsics support (PR #133907)

[Matt Arsenault via llvm-commits]

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@@ -3385,8 +3385,26 @@ void SelectionDAGBuilder::visitCallBr(const CallBrInst &I) {
              {LLVMContext::OB_deopt, LLVMContext::OB_funclet}) &&
          "Cannot lower callbrs with arbitrary operand bundles yet!");
 
-  assert(I.isInlineAsm() && "Only know how to handle inlineasm callbr");
-  visitInlineAsm(I);
+  if (I.isInlineAsm()) {
+    visitInlineAsm(I);
+  } else if (I.getIntrinsicID() != Intrinsic::not_intrinsic) {
+    switch (I.getIntrinsicID()) {
+    default:
+      report_fatal_error("Unsupported intrinsic for callbr");
+    case Intrinsic::amdgcn_kill:
+      if (I.getNumIndirectDests() != 1)
+        report_fatal_error(
+            "amdgcn.kill supportes exactly one indirect destination");
+      CallInst *CI =
+          CallInst::Create(I.getFunctionType(), I.getCalledFunction(),
+                           SmallVector<Value *, 1>(I.args()));
+      visitCall(*CI);
+      CI->deleteValue();
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arsenm wrote:

Abstract the visitCall logic into a utility you can share. Codegen is not allowed to modify the IR 

https://github.com/llvm/llvm-project/pull/133907