Instead of testing whether an instruction dominates the loop preheader,
test whether it properly dominates the loop header. This is equivalent
when the loop has a preheader, and has the advantage of working when
the loop doesn't have a preheader. Since IVUsers doesn't Require
LoopSimplify, the loop isn't guaranteed to have a preheader.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82899 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/IVUsers.cpp b/lib/Analysis/IVUsers.cpp
index ecb7df8..543e017 100644
--- a/lib/Analysis/IVUsers.cpp
+++ b/lib/Analysis/IVUsers.cpp
@@ -121,11 +121,11 @@
Start = SE->getAddExpr(Start, AddRecStart);
- // If stride is an instruction, make sure it dominates the loop preheader.
+ // If stride is an instruction, make sure it properly dominates the header.
// Otherwise we could end up with a use before def situation.
if (!isa<SCEVConstant>(AddRecStride)) {
- BasicBlock *Preheader = L->getLoopPreheader();
- if (!AddRecStride->dominates(Preheader, DT))
+ BasicBlock *Header = L->getHeader();
+ if (!AddRecStride->properlyDominates(Header, DT))
return false;
DEBUG(errs() << "[" << L->getHeader()->getName()