Fix a scalar evolution bug. Reversing everything

does not work because of 0; 2>0 but -2U is also >0.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@49928 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index 4b4b97e28624bb9adb706ec585a026f8d45603a2..0508bb76c1ec83ab3a4982103b0f04df6d1ed3c6 100644 (file)
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -1980,8 +1980,7 @@ SCEVHandle ScalarEvolutionsImpl::ComputeIterationCount(const Loop *L) {
     break;
   }
   case ICmpInst::ICMP_UGT: {
-    SCEVHandle TC = HowManyLessThans(SE.getNegativeSCEV(LHS),
-                                     SE.getNegativeSCEV(RHS), L, false);
+    SCEVHandle TC = HowFarToZero(SE.getMinusSCEV(LHS, RHS), L);
     if (!isa<SCEVCouldNotCompute>(TC)) return TC;
     break;
   }