ART: ChildBlockIterator Implementation
- Added the API to be able to walk through a BasicBlock's children directly.
- When calling Reset(GrowableArray*), there is an assignment to the g_list_
member. This is not possible with the g_list_ being const.
Change-Id: I25d06484fd93848d80ccf96a1324058370b2ee46
Signed-Off-By: Jean Christophe Beyler <jean.christophe.beyler@intel.com>
Signed-off-by: Razvan A Lupusoru <razvan.a.lupusoru@intel.com>
Signed-off-by: Yixin Shou <yixin.shou@intel.com>
Signed-off-by: Chao-ying Fu <chao-ying.fu@intel.com>
Signed-off-by: Udayan Banerji <udayan.banerji@intel.com>
diff --git a/compiler/dex/mir_graph.cc b/compiler/dex/mir_graph.cc
index 30d0bc3..ca90a83 100644
--- a/compiler/dex/mir_graph.cc
+++ b/compiler/dex/mir_graph.cc
@@ -1257,4 +1257,55 @@
DoDFSPreOrderSSARename(GetEntryBlock());
}
+ChildBlockIterator::ChildBlockIterator(BasicBlock* bb, MIRGraph* mir_graph)
+ : basic_block_(bb), mir_graph_(mir_graph), visited_fallthrough_(false),
+ visited_taken_(false), have_successors_(false) {
+ // Check if we actually do have successors.
+ if (basic_block_ != 0 && basic_block_->successor_block_list_type != kNotUsed) {
+ have_successors_ = true;
+ successor_iter_.Reset(basic_block_->successor_blocks);
+ }
+}
+
+BasicBlock* ChildBlockIterator::Next() {
+ // We check if we have a basic block. If we don't we cannot get next child.
+ if (basic_block_ == nullptr) {
+ return nullptr;
+ }
+
+ // If we haven't visited fallthrough, return that.
+ if (visited_fallthrough_ == false) {
+ visited_fallthrough_ = true;
+
+ BasicBlock* result = mir_graph_->GetBasicBlock(basic_block_->fall_through);
+ if (result != nullptr) {
+ return result;
+ }
+ }
+
+ // If we haven't visited taken, return that.
+ if (visited_taken_ == false) {
+ visited_taken_ = true;
+
+ BasicBlock* result = mir_graph_->GetBasicBlock(basic_block_->taken);
+ if (result != nullptr) {
+ return result;
+ }
+ }
+
+ // We visited both taken and fallthrough. Now check if we have successors we need to visit.
+ if (have_successors_ == true) {
+ // Get information about next successor block.
+ SuccessorBlockInfo* successor_block_info = successor_iter_.Next();
+
+ // If we don't have anymore successors, return nullptr.
+ if (successor_block_info != nullptr) {
+ return mir_graph_->GetBasicBlock(successor_block_info->block);
+ }
+ }
+
+ // We do not have anything.
+ return nullptr;
+}
+
} // namespace art
diff --git a/compiler/dex/mir_graph.h b/compiler/dex/mir_graph.h
index c728d84..85a2d04 100644
--- a/compiler/dex/mir_graph.h
+++ b/compiler/dex/mir_graph.h
@@ -341,6 +341,29 @@
int key;
};
+/**
+ * @class ChildBlockIterator
+ * @brief Enable an easy iteration of the children.
+ */
+class ChildBlockIterator {
+ public:
+ /**
+ * @brief Constructs a child iterator.
+ * @param bb The basic whose children we need to iterate through.
+ * @param mir_graph The MIRGraph used to get the basic block during iteration.
+ */
+ ChildBlockIterator(BasicBlock* bb, MIRGraph* mir_graph);
+ BasicBlock* Next();
+
+ private:
+ BasicBlock* basic_block_;
+ MIRGraph* mir_graph_;
+ bool visited_fallthrough_;
+ bool visited_taken_;
+ bool have_successors_;
+ GrowableArray<SuccessorBlockInfo*>::Iterator successor_iter_;
+};
+
/*
* Whereas a SSA name describes a definition of a Dalvik vreg, the RegLocation describes
* the type of an SSA name (and, can also be used by code generators to record where the
diff --git a/compiler/utils/growable_array.h b/compiler/utils/growable_array.h
index 659b4f7..e703d8e 100644
--- a/compiler/utils/growable_array.h
+++ b/compiler/utils/growable_array.h
@@ -78,7 +78,7 @@
private:
size_t idx_;
- GrowableArray* const g_list_;
+ GrowableArray* g_list_;
};
GrowableArray(ArenaAllocator* arena, size_t init_length, OatListKind kind = kGrowableArrayMisc)