When attempting to sign-extend an addrec by interpreting
the step value as unsigned, the start value and the addrec
itself still need to be treated as signed.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77078 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index 49af579..6592e0d 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -923,10 +923,10 @@
                        getTruncateOrZeroExtend(Step, Start->getType()));
           Add = getAddExpr(Start, UMul);
           OperandExtendedAdd =
-            getAddExpr(getZeroExtendExpr(Start, WideTy),
+            getAddExpr(getSignExtendExpr(Start, WideTy),
                        getMulExpr(getZeroExtendExpr(CastedMaxBECount, WideTy),
                                   getZeroExtendExpr(Step, WideTy)));
-          if (getZeroExtendExpr(Add, WideTy) == OperandExtendedAdd)
+          if (getSignExtendExpr(Add, WideTy) == OperandExtendedAdd)
             // Return the expression with the addrec on the outside.
             return getAddRecExpr(getSignExtendExpr(Start, Ty),
                                  getZeroExtendExpr(Step, Ty),