[llvm] [LV] Skip sentinel value for FindLastIV reductions when start value is provably less than IV start. (PR #141788)

[Ramkumar Ramachandra via llvm-commits]

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@@ -97,9 +98,10 @@ class RecurrenceDescriptor {
         : IsRecurrence(IsRecur), PatternLastInst(I),
           RecKind(RecurKind::None), ExactFPMathInst(ExactFP) {}
 
-    InstDesc(Instruction *I, RecurKind K, Instruction *ExactFP = nullptr)
+    InstDesc(Instruction *I, RecurKind K, Value *Sentinel = nullptr,
+             Instruction *ExactFP = nullptr)
         : IsRecurrence(true), PatternLastInst(I), RecKind(K),
-          ExactFPMathInst(ExactFP) {}
+          ExactFPMathInst(ExactFP), SentinelValue(Sentinel) {}
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artagnon wrote:

I don't think ExactFP is ever used via this constructor call: you can strip it?

https://github.com/llvm/llvm-project/pull/141788