Tell ScalarEvolution to forget a loop before starting to delete it.
This way ScalarEvolution can examine the loop to determine what state
it needs to update, if it chooses.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75029 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/LoopDeletion.cpp b/lib/Transforms/Scalar/LoopDeletion.cpp
index 76a773a..38d0b39 100644
--- a/lib/Transforms/Scalar/LoopDeletion.cpp
+++ b/lib/Transforms/Scalar/LoopDeletion.cpp
@@ -199,7 +199,12 @@
// Because we're deleting a large chunk of code at once, the sequence in which
// we remove things is very important to avoid invalidation issues. Don't
// mess with this unless you have good reason and know what you're doing.
-
+
+ // Tell ScalarEvolution that the loop is deleted. Do this before
+ // deleting the loop so that ScalarEvolution can look at the loop
+ // to determine what it needs to clean up.
+ SE.forgetLoopBackedgeTakenCount(L);
+
// Move simple loop-invariant expressions out of the loop, since they
// might be needed by the exit phis.
for (Loop::block_iterator LI = L->block_begin(), LE = L->block_end();
@@ -248,11 +253,6 @@
(*LI)->dropAllReferences();
}
- // Tell ScalarEvolution that the loop is deleted. Do this before
- // deleting the loop so that ScalarEvolution can look at the loop
- // to determine what it needs to clean up.
- SE.forgetLoopBackedgeTakenCount(L);
-
// Erase the instructions and the blocks without having to worry
// about ordering because we already dropped the references.
// NOTE: This iteration is safe because erasing the block does not remove its