[llvm] [LAA] Be more careful when evaluating AddRecs at symbolic max BTC. (PR #128061)

[David Sherwood via llvm-commits]

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@@ -72,10 +72,10 @@ define void @all_exits_dominate_latch_countable_exits_at_most_500_iterations_not
 ; CHECK-NEXT:          %gep.A = getelementptr inbounds i32, ptr %A, i64 %iv
 ; CHECK-NEXT:      Grouped accesses:
 ; CHECK-NEXT:        Group [[GRP3]]:
-; CHECK-NEXT:          (Low: %B High: (2000 + %B))
+; CHECK-NEXT:          (Low: %B High: inttoptr (i64 -1 to ptr))
 ; CHECK-NEXT:            Member: {%B,+,4}<nuw><%loop.header>
 ; CHECK-NEXT:        Group [[GRP4]]:
-; CHECK-NEXT:          (Low: %A High: (2000 + %A))
+; CHECK-NEXT:          (Low: %A High: inttoptr (i64 -1 to ptr))
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david-arm wrote:

I'm probably missing something here, but this seems too conservative right? The loop absolutely cannot execute more than 500 times even if we take an early exit. Even before the High of `2000 + %A` was a conservative worst case based on not taking an early exit. Is the idea to fix existing bugs for now in this patch and possibly improve upon this later? Or have I just missed some fundamental reasoning?

https://github.com/llvm/llvm-project/pull/128061