[llvm] [SCEV] Introduce IncrementNSUW, replacing NSSW (PR #219559)

[David Sherwood via llvm-commits]

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@@ -35,7 +35,13 @@ define void @test1(i32 %N, i32 %M) {
 ; CHECK-NEXT:  Loop %bb3: Unpredictable symbolic max backedge-taken count.
 ; CHECK-NEXT:  Loop %bb3: Predicated backedge-taken count is (1 + (-1 smax %M))
 ; CHECK-NEXT:   Predicates:
-; CHECK-NEXT:      {0,+,1}<%bb3> Added Flags: <nssw>
+; CHECK-NEXT:      {0,+,1}<%bb3> Added Flags: <nsuw>
+; CHECK-NEXT:  Loop %bb3: Predicated constant max backedge-taken count is i32 -2147483648
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david-arm wrote:

These checks look more expensive now and we're less likely to enter the loop?

https://github.com/llvm/llvm-project/pull/219559