[PATCH] D89456: [SCEV] Introduce SCEVPtrToIntExpr (PR46786)

[Max Kazantsev via Phabricator via llvm-commits]

mkazantsev added a comment.

I don't think that mixing `null` into AddRecs is correct and expected.



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Comment at: llvm/include/llvm/Analysis/ScalarEvolutionExpressions.h:100
+    static bool classof(const SCEV *S) {
+      return S->getSCEVType() == scPtrToInt || S->getSCEVType() == scTruncate ||
+             S->getSCEVType() == scZeroExtend ||
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Nit: better add it last, and keep it 1 per line.


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Comment at: llvm/test/Analysis/ScalarEvolution/max-backedge-taken-count-guard-info.ll:534
 ; CHECK-NEXT:    %text.addr.5 = phi i8* [ %incdec.ptr112, %while.cond111 ], [ null, %while.body ]
-; CHECK-NEXT:    --> {0,+,-1}<nw><%while.cond111> U: full-set S: full-set Exits: <<Unknown>> LoopDispositions: { %while.cond111: Computable, %while.body: Variant }
+; CHECK-NEXT:    --> {null,+,-1}<nw><%while.cond111> U: full-set S: full-set Exits: <<Unknown>> LoopDispositions: { %while.cond111: Computable, %while.body: Variant }
 ; CHECK-NEXT:    %incdec.ptr112 = getelementptr inbounds i8, i8* %text.addr.5, i64 -1
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What's the type of the AddRec here? Is it an integral-type AddRec with pointer base? If so, this will be a source of various bugs because the code relies on fact that AddRec's type matches Base's type in many places.


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