ART: Implement SuperblockCloner.
SuperblockCloner provides a feature of cloning subgraphs in a
smart, high level way without fine grain manipulation with IR;
data flow and graph properties are resolved/adjusted automatically.
The clone transformation is defined by specifying a set of basic
blocks to copy and a set of rules how to treat edges, remap their
successors. By using this approach such optimizations as Branch
Target Expansion, Loop Peeling, Loop Unrolling can be implemented.
Test: superblock_cloner_test.cc.
Change-Id: Ibeede38195376ca35f44ba9015491e50b3a5b87e
diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h
index d4382c6..180893d 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -826,6 +826,10 @@
// Finds blocks that are part of this loop.
void Populate();
+ // Updates blocks population of the loop and all of its outer' ones recursively after the
+ // population of the inner loop is updated.
+ void PopulateInnerLoopUpwards(HLoopInformation* inner_loop);
+
// Returns whether this loop information contains `block`.
// Note that this loop information *must* be populated before entering this function.
bool Contains(const HBasicBlock& block) const;
@@ -856,6 +860,12 @@
bool HasExitEdge() const;
+ // Resets back edge and blocks-in-loop data.
+ void ResetBasicBlockData() {
+ back_edges_.clear();
+ ClearAllBlocks();
+ }
+
private:
// Internal recursive implementation of `Populate`.
void PopulateRecursive(HBasicBlock* block);
@@ -998,6 +1008,18 @@
loop_information_->AddBackEdge(back_edge);
}
+ // Registers a back edge; if the block was not a loop header before the call associates a newly
+ // created loop info with it.
+ //
+ // Used in SuperblockCloner to preserve LoopInformation object instead of reseting loop
+ // info for all blocks during back edges recalculation.
+ void AddBackEdgeWhileUpdating(HBasicBlock* back_edge) {
+ if (loop_information_ == nullptr || loop_information_->GetHeader() != this) {
+ loop_information_ = new (graph_->GetAllocator()) HLoopInformation(this, graph_);
+ }
+ loop_information_->AddBackEdge(back_edge);
+ }
+
HGraph* GetGraph() const { return graph_; }
void SetGraph(HGraph* graph) { graph_ = graph; }
@@ -7298,19 +7320,19 @@
class CloneAndReplaceInstructionVisitor : public HGraphDelegateVisitor {
public:
explicit CloneAndReplaceInstructionVisitor(HGraph* graph)
- : HGraphDelegateVisitor(graph), instr_replaced_by_clones_count(0) {}
+ : HGraphDelegateVisitor(graph), instr_replaced_by_clones_count_(0) {}
void VisitInstruction(HInstruction* instruction) OVERRIDE {
if (instruction->IsClonable()) {
ReplaceInstrOrPhiByClone(instruction);
- instr_replaced_by_clones_count++;
+ instr_replaced_by_clones_count_++;
}
}
- size_t GetInstrReplacedByClonesCount() const { return instr_replaced_by_clones_count; }
+ size_t GetInstrReplacedByClonesCount() const { return instr_replaced_by_clones_count_; }
private:
- size_t instr_replaced_by_clones_count;
+ size_t instr_replaced_by_clones_count_;
DISALLOW_COPY_AND_ASSIGN(CloneAndReplaceInstructionVisitor);
};