Skip loop optimization if there is no loop in the graph.
LinearizeGraph() does quite some allocations.
Also add some comments on the possible false positives of
some flags.
Test: m test-art-host
Change-Id: I80ef89a2dc031d601e7621d0b22060cd8c17fae3
diff --git a/compiler/optimizing/loop_optimization.cc b/compiler/optimizing/loop_optimization.cc
index 9583838..26c9ab8 100644
--- a/compiler/optimizing/loop_optimization.cc
+++ b/compiler/optimizing/loop_optimization.cc
@@ -71,7 +71,7 @@
void HLoopOptimization::Run() {
// Well-behaved loops only.
// TODO: make this less of a sledgehammer.
- if (graph_->HasTryCatch() || graph_->HasIrreducibleLoops()) {
+ if (!graph_->HasLoops() || graph_->HasTryCatch() || graph_->HasIrreducibleLoops()) {
return;
}
@@ -84,6 +84,10 @@
// Perform loop optimizations.
LocalRun();
+ if (top_loop_ == nullptr) {
+ graph_->SetHasLoops(false);
+ }
+
// Detach.
loop_allocator_ = nullptr;
last_loop_ = top_loop_ = nullptr;
diff --git a/compiler/optimizing/nodes.cc b/compiler/optimizing/nodes.cc
index 71a26eb..62c8910 100644
--- a/compiler/optimizing/nodes.cc
+++ b/compiler/optimizing/nodes.cc
@@ -688,6 +688,7 @@
contains_irreducible_loop_ = true;
graph->SetHasIrreducibleLoops(true);
}
+ graph->SetHasLoops(true);
}
HBasicBlock* HLoopInformation::GetPreHeader() const {
@@ -2032,9 +2033,19 @@
}
}
outer_graph->UpdateMaximumNumberOfOutVRegs(GetMaximumNumberOfOutVRegs());
+
if (HasBoundsChecks()) {
outer_graph->SetHasBoundsChecks(true);
}
+ if (HasLoops()) {
+ outer_graph->SetHasLoops(true);
+ }
+ if (HasIrreducibleLoops()) {
+ outer_graph->SetHasIrreducibleLoops(true);
+ }
+ if (HasTryCatch()) {
+ outer_graph->SetHasTryCatch(true);
+ }
HInstruction* return_value = nullptr;
if (GetBlocks().size() == 3) {
diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h
index 96f9aba..2f258db 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -323,6 +323,7 @@
temporaries_vreg_slots_(0),
has_bounds_checks_(false),
has_try_catch_(false),
+ has_loops_(false),
has_irreducible_loops_(false),
debuggable_(debuggable),
current_instruction_id_(start_instruction_id),
@@ -559,6 +560,9 @@
bool HasTryCatch() const { return has_try_catch_; }
void SetHasTryCatch(bool value) { has_try_catch_ = value; }
+ bool HasLoops() const { return has_loops_; }
+ void SetHasLoops(bool value) { has_loops_ = value; }
+
bool HasIrreducibleLoops() const { return has_irreducible_loops_; }
void SetHasIrreducibleLoops(bool value) { has_irreducible_loops_ = value; }
@@ -637,14 +641,26 @@
// Number of vreg size slots that the temporaries use (used in baseline compiler).
size_t temporaries_vreg_slots_;
- // Has bounds checks. We can totally skip BCE if it's false.
+ // Flag whether there are bounds checks in the graph. We can skip
+ // BCE if it's false. It's only best effort to keep it up to date in
+ // the presence of code elimination so there might be false positives.
bool has_bounds_checks_;
- // Flag whether there are any try/catch blocks in the graph. We will skip
- // try/catch-related passes if false.
+ // Flag whether there are try/catch blocks in the graph. We will skip
+ // try/catch-related passes if it's false. It's only best effort to keep
+ // it up to date in the presence of code elimination so there might be
+ // false positives.
bool has_try_catch_;
- // Flag whether there are any irreducible loops in the graph.
+ // Flag whether there are any loops in the graph. We can skip loop
+ // optimization if it's false. It's only best effort to keep it up
+ // to date in the presence of code elimination so there might be false
+ // positives.
+ bool has_loops_;
+
+ // Flag whether there are any irreducible loops in the graph. It's only
+ // best effort to keep it up to date in the presence of code elimination
+ // so there might be false positives.
bool has_irreducible_loops_;
// Indicates whether the graph should be compiled in a way that
