Optimize ScalarEvolution::getAddExpr's duplicate operand detection
by having it finish processing the whole operand list before
starting the whole getAddExpr process over again, instead of
immediately after the first duplicate is found.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110914 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index b3ddfc0..6e41048 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -1373,6 +1373,7 @@
// so, merge them together into an multiply expression. Since we sorted the
// list, these values are required to be adjacent.
const Type *Ty = Ops[0]->getType();
+ bool FoundMatch = false;
for (unsigned i = 0, e = Ops.size()-1; i != e; ++i)
if (Ops[i] == Ops[i+1]) { // X + Y + Y --> X + Y*2
// Found a match, merge the two values into a multiply, and add any
@@ -1381,10 +1382,13 @@
const SCEV *Mul = getMulExpr(Ops[i], Two);
if (Ops.size() == 2)
return Mul;
- Ops.erase(Ops.begin()+i, Ops.begin()+i+2);
- Ops.push_back(Mul);
- return getAddExpr(Ops, HasNUW, HasNSW);
+ Ops[i] = Mul;
+ Ops.erase(Ops.begin()+i+1);
+ --i; --e;
+ FoundMatch = true;
}
+ if (FoundMatch)
+ return getAddExpr(Ops, HasNUW, HasNSW);
// Check for truncates. If all the operands are truncated from the same
// type, see if factoring out the truncate would permit the result to be