[llvm-branch-commits] [llvm] [SimplifyCFG] Do not thread branches into uncontrolled convergent regions (PR #204958)

[Shilei Tian via llvm-branch-commits]

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@@ -3543,6 +3543,39 @@ static ConstantInt *getKnownValueOnEdge(Value *V, BasicBlock *From,
   return nullptr;
 }
 
+static bool isUncontrolledConvergentCall(CallBase *CB) {
+  return CB->isConvergent() && !isa<ConvergenceControlInst>(CB) &&
+         !CB->getConvergenceControlToken();
+}
+
+static bool reachesUncontrolledConvergentCallBeforeBlock(BasicBlock *From,
+                                                         BasicBlock *StopBB) {
+  SmallVector<BasicBlock *, 8> Worklist;
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shiltian wrote:

I think it is not safe because a non-convergent function can have convergent operations.

https://github.com/llvm/llvm-project/pull/204958