Make LinearizeGraph() public (and move it to nodes files)
Rationale:
It is strange that HLinearOrderIterator is defined (and visible)
in nodes.h, but clients have no way to build this order. This CL
makes the building available at the usual place.
Change-Id: Ib66f2edf6dfc8edd6b429bd4bea3ac7e37440b28
Tests: m test-art
diff --git a/compiler/optimizing/ssa_liveness_analysis.cc b/compiler/optimizing/ssa_liveness_analysis.cc
index a4d52d7..9ce34aa 100644
--- a/compiler/optimizing/ssa_liveness_analysis.cc
+++ b/compiler/optimizing/ssa_liveness_analysis.cc
@@ -23,119 +23,11 @@
namespace art {
void SsaLivenessAnalysis::Analyze() {
- LinearizeGraph();
+ graph_->Linearize();
NumberInstructions();
ComputeLiveness();
}
-static bool IsLoop(HLoopInformation* info) {
- return info != nullptr;
-}
-
-static bool InSameLoop(HLoopInformation* first_loop, HLoopInformation* second_loop) {
- return first_loop == second_loop;
-}
-
-static bool IsInnerLoop(HLoopInformation* outer, HLoopInformation* inner) {
- return (inner != outer)
- && (inner != nullptr)
- && (outer != nullptr)
- && inner->IsIn(*outer);
-}
-
-static void AddToListForLinearization(ArenaVector<HBasicBlock*>* worklist, HBasicBlock* block) {
- HLoopInformation* block_loop = block->GetLoopInformation();
- auto insert_pos = worklist->rbegin(); // insert_pos.base() will be the actual position.
- for (auto end = worklist->rend(); insert_pos != end; ++insert_pos) {
- HBasicBlock* current = *insert_pos;
- HLoopInformation* current_loop = current->GetLoopInformation();
- if (InSameLoop(block_loop, current_loop)
- || !IsLoop(current_loop)
- || IsInnerLoop(current_loop, block_loop)) {
- // The block can be processed immediately.
- break;
- }
- }
- worklist->insert(insert_pos.base(), block);
-}
-
-static bool IsLinearOrderWellFormed(const HGraph& graph) {
- for (HBasicBlock* header : graph.GetBlocks()) {
- if (header == nullptr || !header->IsLoopHeader()) {
- continue;
- }
-
- HLoopInformation* loop = header->GetLoopInformation();
- size_t num_blocks = loop->GetBlocks().NumSetBits();
- size_t found_blocks = 0u;
-
- for (HLinearOrderIterator it(graph); !it.Done(); it.Advance()) {
- HBasicBlock* current = it.Current();
- if (loop->Contains(*current)) {
- found_blocks++;
- if (found_blocks == 1u && current != header) {
- // First block is not the header.
- return false;
- } else if (found_blocks == num_blocks && !loop->IsBackEdge(*current)) {
- // Last block is not a back edge.
- return false;
- }
- } else if (found_blocks != 0u && found_blocks != num_blocks) {
- // Blocks are not adjacent.
- return false;
- }
- }
- DCHECK_EQ(found_blocks, num_blocks);
- }
-
- return true;
-}
-
-void SsaLivenessAnalysis::LinearizeGraph() {
- // Create a reverse post ordering with the following properties:
- // - Blocks in a loop are consecutive,
- // - Back-edge is the last block before loop exits.
-
- // (1): Record the number of forward predecessors for each block. This is to
- // ensure the resulting order is reverse post order. We could use the
- // current reverse post order in the graph, but it would require making
- // order queries to a GrowableArray, which is not the best data structure
- // for it.
- ArenaVector<uint32_t> forward_predecessors(graph_->GetBlocks().size(),
- graph_->GetArena()->Adapter(kArenaAllocSsaLiveness));
- for (HReversePostOrderIterator it(*graph_); !it.Done(); it.Advance()) {
- HBasicBlock* block = it.Current();
- size_t number_of_forward_predecessors = block->GetPredecessors().size();
- if (block->IsLoopHeader()) {
- number_of_forward_predecessors -= block->GetLoopInformation()->NumberOfBackEdges();
- }
- forward_predecessors[block->GetBlockId()] = number_of_forward_predecessors;
- }
-
- // (2): Following a worklist approach, first start with the entry block, and
- // iterate over the successors. When all non-back edge predecessors of a
- // successor block are visited, the successor block is added in the worklist
- // following an order that satisfies the requirements to build our linear graph.
- graph_->linear_order_.reserve(graph_->GetReversePostOrder().size());
- ArenaVector<HBasicBlock*> worklist(graph_->GetArena()->Adapter(kArenaAllocSsaLiveness));
- worklist.push_back(graph_->GetEntryBlock());
- do {
- HBasicBlock* current = worklist.back();
- worklist.pop_back();
- graph_->linear_order_.push_back(current);
- for (HBasicBlock* successor : current->GetSuccessors()) {
- int block_id = successor->GetBlockId();
- size_t number_of_remaining_predecessors = forward_predecessors[block_id];
- if (number_of_remaining_predecessors == 1) {
- AddToListForLinearization(&worklist, successor);
- }
- forward_predecessors[block_id] = number_of_remaining_predecessors - 1;
- }
- } while (!worklist.empty());
-
- DCHECK(graph_->HasIrreducibleLoops() || IsLinearOrderWellFormed(*graph_));
-}
-
void SsaLivenessAnalysis::NumberInstructions() {
int ssa_index = 0;
size_t lifetime_position = 0;