Quick: In GVN, apply modifications early if outside loop.
To improve GVN performance, apply modifications to blocks
outside loops during the initial convergence phase. During
the post processing phase, apply modifications only to the
blocks belonging to loops.
Also clean up the check whether to run the LVN and add the
capability to limit the maximum number of nested loops we
allow the GVN to process.
Change-Id: Ie7f1254f91a442397c06a325d5d314d8f58e5012
diff --git a/compiler/dex/dataflow_iterator-inl.h b/compiler/dex/dataflow_iterator-inl.h
index 89f2b5c..6e25db6 100644
--- a/compiler/dex/dataflow_iterator-inl.h
+++ b/compiler/dex/dataflow_iterator-inl.h
@@ -115,6 +115,30 @@
return res;
}
+inline BasicBlock* TopologicalSortIterator::Next(bool had_change) {
+ // Update changed: if had_changed is true, we remember it for the whole iteration.
+ changed_ |= had_change;
+
+ while (loop_head_stack_->size() != 0u &&
+ (*loop_ends_)[loop_head_stack_->back().first] == idx_) {
+ loop_head_stack_->pop_back();
+ }
+
+ if (idx_ == end_idx_) {
+ return nullptr;
+ }
+
+ // Get next block and return it.
+ BasicBlockId idx = idx_;
+ idx_ += 1;
+ BasicBlock* bb = mir_graph_->GetBasicBlock((*block_id_list_)[idx]);
+ DCHECK(bb != nullptr);
+ if ((*loop_ends_)[idx] != 0u) {
+ loop_head_stack_->push_back(std::make_pair(idx, false)); // Not recalculating.
+ }
+ return bb;
+}
+
inline BasicBlock* LoopRepeatingTopologicalSortIterator::Next(bool had_change) {
if (idx_ != 0) {
// Mark last processed block visited.