ART: Fix loop information after dead code elimination
Compilation failed when only some blocks of a loop were removed during
dead code elimination.
Bug: 20680703
Change-Id: If31025169ca493f0d7f7f2788576e98d05f03394
diff --git a/compiler/optimizing/nodes.cc b/compiler/optimizing/nodes.cc
index 699987c..f07f4c7 100644
--- a/compiler/optimizing/nodes.cc
+++ b/compiler/optimizing/nodes.cc
@@ -376,7 +376,6 @@
}
HBasicBlock* HLoopInformation::GetPreHeader() const {
- DCHECK_EQ(header_->GetPredecessors().Size(), 2u);
return header_->GetDominator();
}
@@ -1038,6 +1037,20 @@
SetGraph(nullptr);
}
+void HBasicBlock::UpdateLoopInformation() {
+ // Check if loop information points to a dismantled loop. If so, replace with
+ // the loop information of a larger loop which contains this block, or nullptr
+ // otherwise. We iterate in case the larger loop has been destroyed too.
+ while (IsInLoop() && loop_information_->GetBackEdges().IsEmpty()) {
+ if (IsLoopHeader()) {
+ HSuspendCheck* suspend_check = loop_information_->GetSuspendCheck();
+ DCHECK_EQ(suspend_check->GetBlock(), this);
+ RemoveInstruction(suspend_check);
+ }
+ loop_information_ = loop_information_->GetPreHeader()->GetLoopInformation();
+ }
+}
+
void HBasicBlock::MergeWith(HBasicBlock* other) {
DCHECK_EQ(GetGraph(), other->GetGraph());
DCHECK(GetDominatedBlocks().Contains(other));