Optimizing: Reduce arena memory used by GraphChecker.
Use member variables to reuse the storage instead of
repeatedly allocating new storage for local variables.
Bug: 27690481
Change-Id: I614db9b8614d585653cfbff62e9cf7d7f0c58810
diff --git a/compiler/optimizing/graph_checker.cc b/compiler/optimizing/graph_checker.cc
index e5c8c47..f2e77e2 100644
--- a/compiler/optimizing/graph_checker.cc
+++ b/compiler/optimizing/graph_checker.cc
@@ -32,11 +32,9 @@
// Check consistency with respect to predecessors of `block`.
// Note: Counting duplicates with a sorted vector uses up to 6x less memory
- // than ArenaSafeMap<HBasicBlock*, size_t>.
- ArenaVector<HBasicBlock*> sorted_predecessors(
- block->GetPredecessors().begin(),
- block->GetPredecessors().end(),
- GetGraph()->GetArena()->Adapter(kArenaAllocGraphChecker));
+ // than ArenaSafeMap<HBasicBlock*, size_t> and also allows storage reuse.
+ ArenaVector<HBasicBlock*>& sorted_predecessors = blocks_storage_;
+ sorted_predecessors.assign(block->GetPredecessors().begin(), block->GetPredecessors().end());
std::sort(sorted_predecessors.begin(), sorted_predecessors.end());
for (auto it = sorted_predecessors.begin(), end = sorted_predecessors.end(); it != end; ) {
HBasicBlock* p = *it++;
@@ -57,11 +55,9 @@
// Check consistency with respect to successors of `block`.
// Note: Counting duplicates with a sorted vector uses up to 6x less memory
- // than ArenaSafeMap<HBasicBlock*, size_t>.
- ArenaVector<HBasicBlock*> sorted_successors(
- block->GetSuccessors().begin(),
- block->GetSuccessors().end(),
- GetGraph()->GetArena()->Adapter(kArenaAllocGraphChecker));
+ // than ArenaSafeMap<HBasicBlock*, size_t> and also allows storage reuse.
+ ArenaVector<HBasicBlock*>& sorted_successors = blocks_storage_;
+ sorted_successors.assign(block->GetSuccessors().begin(), block->GetSuccessors().end());
std::sort(sorted_successors.begin(), sorted_successors.end());
for (auto it = sorted_successors.begin(), end = sorted_successors.end(); it != end; ) {
HBasicBlock* s = *it++;
@@ -811,10 +807,11 @@
phi->GetRegNumber(),
type_str.str().c_str()));
} else {
- ArenaBitVector visited(GetGraph()->GetArena(),
- 0,
- /* expandable */ true,
- kArenaAllocGraphChecker);
+ // If we get here, make sure we allocate all the necessary storage at once
+ // because the BitVector reallocation strategy has very bad worst-case behavior.
+ ArenaBitVector& visited = visited_storage_;
+ visited.SetBit(GetGraph()->GetCurrentInstructionId());
+ visited.ClearAllBits();
if (!IsConstantEquivalent(phi, other_phi, &visited)) {
AddError(StringPrintf("Two phis (%d and %d) found for VReg %d but they "
"are not equivalents of constants.",
diff --git a/compiler/optimizing/graph_checker.h b/compiler/optimizing/graph_checker.h
index 27d5621..a536b30 100644
--- a/compiler/optimizing/graph_checker.h
+++ b/compiler/optimizing/graph_checker.h
@@ -33,7 +33,9 @@
seen_ids_(graph->GetArena(),
graph->GetCurrentInstructionId(),
false,
- kArenaAllocGraphChecker) {}
+ kArenaAllocGraphChecker),
+ blocks_storage_(graph->GetArena()->Adapter(kArenaAllocGraphChecker)),
+ visited_storage_(graph->GetArena(), 0u, true, kArenaAllocGraphChecker) {}
// Check the whole graph (in reverse post-order).
void Run() {
@@ -102,6 +104,10 @@
const char* const dump_prefix_;
ArenaBitVector seen_ids_;
+ // To reduce the total arena memory allocation, we reuse the same storage.
+ ArenaVector<HBasicBlock*> blocks_storage_;
+ ArenaBitVector visited_storage_;
+
DISALLOW_COPY_AND_ASSIGN(GraphChecker);
};