Fold a binary operator with constant operands when expanding code for a SCEV.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37602 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ScalarEvolutionExpander.cpp b/lib/Analysis/ScalarEvolutionExpander.cpp
index c8c683c..3e590d6 100644
--- a/lib/Analysis/ScalarEvolutionExpander.cpp
+++ b/lib/Analysis/ScalarEvolutionExpander.cpp
@@ -72,6 +72,11 @@
/// of work to avoid inserting an obviously redundant operation.
Value *SCEVExpander::InsertBinop(Instruction::BinaryOps Opcode, Value *LHS,
Value *RHS, Instruction *&InsertPt) {
+ // Fold a binop with constant operands.
+ if (Constant *CLHS = dyn_cast<Constant>(LHS))
+ if (Constant *CRHS = dyn_cast<Constant>(RHS))
+ return ConstantExpr::get(Opcode, CLHS, CRHS);
+
// Do a quick scan to see if we have this binop nearby. If so, reuse it.
unsigned ScanLimit = 6;
for (BasicBlock::iterator IP = InsertPt, E = InsertPt->getParent()->begin();