[llvm] [ValueTracking] Handle recursive select/PHI in ComputeKnownBits/IsKnownNonZero (PR #114689)

[Yingwei Zheng via llvm-commits]

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@@ -1580,14 +1582,22 @@ static void computeKnownBitsFromOperator(const Operator *I,
                                                : SI->getTrueValue();
             IncDepth = Depth + 1;
           }
+        } else if (auto *IncPhi = dyn_cast<PHINode>(IncValue);
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dtcxzyw wrote:

We need a helper function `void breakSelfRecursion(Use &U, PHINode *PHI, Value*& ValOut, unsigned &DepthInOut, Instruction *&CtxIOut)` to avoid duplicate logic.


https://github.com/llvm/llvm-project/pull/114689