[PATCH] D32105: [IVUsers] don't bail out of normalizing non-affine add recs

[Sanjoy Das via Phabricator via llvm-commits]

This revision was automatically updated to reflect the committed changes.
Closed by commit rL301298: [IVUsers] Don't bail out of normalizing non-affine add recs (authored by sanjoy).

Changed prior to commit:
  https://reviews.llvm.org/D32105?vs=95366&id=96508#toc

Repository:
  rL LLVM

https://reviews.llvm.org/D32105

Files:
  llvm/trunk/lib/Analysis/IVUsers.cpp
  llvm/trunk/test/Analysis/IVUsers/quadradic-exit-value.ll


Index: llvm/trunk/lib/Analysis/IVUsers.cpp
===================================================================
--- llvm/trunk/lib/Analysis/IVUsers.cpp
+++ llvm/trunk/lib/Analysis/IVUsers.cpp
@@ -253,18 +253,8 @@
       const SCEV *OriginalISE = ISE;
 
       auto NormalizePred = [&](const SCEVAddRecExpr *AR) {
-        // We only allow affine AddRecs to be normalized, otherwise we would not
-        // be able to correctly denormalize.
-        // e.g. {1,+,3,+,2} == {-2,+,1,+,2} + {3,+,2}
-        // Normalized form:   {-2,+,1,+,2}
-        // Denormalized form: {1,+,3,+,2}
-        //
-        // However, denormalization would use a different step expression than
-        // normalization (see getPostIncExpr), generating the wrong final
-        // expression: {-2,+,1,+,2} + {1,+,2} => {-1,+,3,+,2}
         auto *L = AR->getLoop();
-        bool Result =
-            AR->isAffine() && IVUseShouldUsePostIncValue(User, I, L, DT);
+        bool Result = IVUseShouldUsePostIncValue(User, I, L, DT);
         if (Result)
           NewUse.PostIncLoops.insert(L);
         return Result;
Index: llvm/trunk/test/Analysis/IVUsers/quadradic-exit-value.ll
===================================================================
--- llvm/trunk/test/Analysis/IVUsers/quadradic-exit-value.ll
+++ llvm/trunk/test/Analysis/IVUsers/quadradic-exit-value.ll
@@ -36,7 +36,7 @@
 ; sure they aren't marked as post-inc users.
 ;
 ; CHECK-LABEL: IV Users for loop %test2.loop
-; CHECK-NO-LCSSA: %sext.us = {0,+,(16777216 + (-16777216 * %sub.us))<nuw><nsw>,+,33554432}<%test2.loop> in %f = ashr i32 %sext.us, 24
+; CHECK-NO-LCSSA: %sext.us = {0,+,(16777216 + (-16777216 * %sub.us))<nuw><nsw>,+,33554432}<%test2.loop> (post-inc with loop %test2.loop) in    %f = ashr i32 %sext.us, 24
 define i32 @test2() {
 entry:
   br label %test2.loop


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