[llvm] [FuncSpec] Update function specialization to handle phi-chains (PR #72903)

[Chuanqi Xu via llvm-commits]

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@@ -217,6 +217,10 @@ class InstCostVisitor : public InstVisitor<InstCostVisitor, Constant *> {
   Cost estimateSwitchInst(SwitchInst &I);
   Cost estimateBranchInst(BranchInst &I);
 
+  bool discoverTransitivelyIncomingValues(
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ChuanqiXu9 wrote:

How about adding comments here so that code readers can understand what is transitive phis and why should we care about them?

https://github.com/llvm/llvm-project/pull/72903