[PATCH] D89381: [SCEV] Use nw flag and symbolic iteration count to sharpen ranges of AddRecs

[Max Kazantsev via Phabricator via llvm-commits]

mkazantsev added inline comments.


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Comment at: llvm/test/Analysis/ScalarEvolution/no-wrap-symbolic-becount.ll:10
 ; CHECK-NEXT:    %indvars.iv = phi i64 [ %indvars.iv.next, %backedge ], [ %0, %entry ]
-; CHECK-NEXT:    --> {(zext i32 %start to i64),+,-1}<nsw><%loop> U: [-4294967295,4294967296) S: [-4294967295,4294967296) Exits: <<Unknown>> LoopDispositions: { %loop: Computable }
+; CHECK-NEXT:    --> {(zext i32 %start to i64),+,-1}<nsw><%loop> U: [-4294967295,4294967296) S: [0,4294967296) Exits: <<Unknown>> LoopDispositions: { %loop: Computable }
 ; CHECK-NEXT:    %iv = phi i32 [ %start, %entry ], [ %iv.next, %backedge ]
----------------
Unsigned range here can also be made [0,0,4294967296)...


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  https://reviews.llvm.org/D89381/new/

https://reviews.llvm.org/D89381