When ScalarEvolution is told to forget the trip count for a loop, have
it also forget any SCEVs associated with loop-header PHIs in the loop,
as they may be dependent on trip count information.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70633 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index d458399..a6d3954 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -2111,9 +2111,7 @@
// conservative estimates made without the benefit
// of trip count information.
if (ItCount.hasAnyInfo())
- for (BasicBlock::iterator I = L->getHeader()->begin();
- PHINode *PN = dyn_cast<PHINode>(I); ++I)
- deleteValueFromRecords(PN);
+ forgetLoopPHIs(L);
}
return Pair.first->second;
}
@@ -2124,6 +2122,16 @@
/// is deleted.
void ScalarEvolution::forgetLoopBackedgeTakenCount(const Loop *L) {
BackedgeTakenCounts.erase(L);
+ forgetLoopPHIs(L);
+}
+
+/// forgetLoopPHIs - Delete the memoized SCEVs associated with the
+/// PHI nodes in the given loop. This is used when the trip count of
+/// the loop may have changed.
+void ScalarEvolution::forgetLoopPHIs(const Loop *L) {
+ for (BasicBlock::iterator I = L->getHeader()->begin();
+ PHINode *PN = dyn_cast<PHINode>(I); ++I)
+ deleteValueFromRecords(PN);
}
/// ComputeBackedgeTakenCount - Compute the number of times the backedge