Improve comment. Thanks for Andrew for the suggestion.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151127 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ScalarEvolutionExpander.cpp b/lib/Analysis/ScalarEvolutionExpander.cpp
index a9473b4..d5f3b74 100644
--- a/lib/Analysis/ScalarEvolutionExpander.cpp
+++ b/lib/Analysis/ScalarEvolutionExpander.cpp
@@ -53,8 +53,9 @@
if (U->getType() == Ty)
if (CastInst *CI = dyn_cast<CastInst>(U))
if (CI->getOpcode() == Op) {
- // If the cast isn't where we want it or if it doesn't dominate
- // a use in BIP, fix it.
+ // If the cast isn't where we want it, create a new cast at IP.
+ // Likewise, do not reuse a cast at BIP because it must dominate
+ // instructions that might be inserted before BIP.
if (BasicBlock::iterator(CI) != IP || BIP == IP) {
// Create a new cast, and leave the old cast in place in case
// it is being used as an insert point. Clear its operand