Another SCEV issue from PR2607; essentially the same issue, but this

time applying to the implicit comparison in smin expressions. The 
correct way to transform an inequality into the opposite 
inequality, either signed or unsigned, is with a not expression.

I looked through the SCEV code, and I don't think there are any more 
occurrences of this issue.

llvm-svn: 54194

1 files changed, 4 insertions, 4 deletions

diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp
index 14c1389b434..bf6bc0b5dc2 100644
--- a/llvm/lib/Analysis/ScalarEvolution.cpp
+++ b/llvm/lib/Analysis/ScalarEvolution.cpp
@@ -1789,10 +1789,10 @@ SCEVHandle ScalarEvolutionsImpl::createSCEV(Value *V) {
         if (LHS == U->getOperand(1) && RHS == U->getOperand(2))
           return SE.getSMaxExpr(getSCEV(LHS), getSCEV(RHS));
         else if (LHS == U->getOperand(2) && RHS == U->getOperand(1))
-          // -smax(-x, -y) == smin(x, y).
-          return SE.getNegativeSCEV(SE.getSMaxExpr(
-                                        SE.getNegativeSCEV(getSCEV(LHS)),
-                                        SE.getNegativeSCEV(getSCEV(RHS))));
+          // ~smax(~x, ~y) == smin(x, y).
+          return SE.getNotSCEV(SE.getSMaxExpr(
+                                   SE.getNotSCEV(getSCEV(LHS)),
+                                   SE.getNotSCEV(getSCEV(RHS))));
         break;
       case ICmpInst::ICMP_ULT:
       case ICmpInst::ICMP_ULE: