From 2477320a8d9de58ede68e2645ea53c10f71dcd57 Mon Sep 17 00:00:00 2001
From: Aart Bik <ajcbik@google.com>
Date: Thu, 26 Apr 2018 10:28:51 -0700
Subject: Step 1 of 2: conditional passes.

Rationale:
The change adds a return value to Run() in preparation of
conditional pass execution. The value returned by Run() is
best effort, returning false means no optimizations were
applied or no useful information was obtained. I filled
in a few cases with more exact information, others
still just return true. In addition, it integrates inlining
as a regular pass, avoiding the ugly "break" into
optimizations1 and optimziations2.

Bug: b/78171933, b/74026074

Test: test-art-host,target
Change-Id: Ia39c5c83c01dcd79841e4b623917d61c754cf075
---
 compiler/optimizing/loop_optimization.cc | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

(limited to 'compiler/optimizing/loop_optimization.cc')

diff --git a/compiler/optimizing/loop_optimization.cc b/compiler/optimizing/loop_optimization.cc
index 1462404932..7f1b319c12 100644
--- a/compiler/optimizing/loop_optimization.cc
+++ b/compiler/optimizing/loop_optimization.cc
@@ -608,11 +608,11 @@ HLoopOptimization::HLoopOptimization(HGraph* graph,
                                                       global_allocator_)) {
 }
 
-void HLoopOptimization::Run() {
+bool HLoopOptimization::Run() {
   // Skip if there is no loop or the graph has try-catch/irreducible loops.
   // TODO: make this less of a sledgehammer.
   if (!graph_->HasLoops() || graph_->HasTryCatch() || graph_->HasIrreducibleLoops()) {
-    return;
+    return false;
   }
 
   // Phase-local allocator.
@@ -620,7 +620,7 @@ void HLoopOptimization::Run() {
   loop_allocator_ = &allocator;
 
   // Perform loop optimizations.
-  LocalRun();
+  bool didLoopOpt = LocalRun();
   if (top_loop_ == nullptr) {
     graph_->SetHasLoops(false);  // no more loops
   }
@@ -628,13 +628,16 @@ void HLoopOptimization::Run() {
   // Detach.
   loop_allocator_ = nullptr;
   last_loop_ = top_loop_ = nullptr;
+
+  return didLoopOpt;
 }
 
 //
 // Loop setup and traversal.
 //
 
-void HLoopOptimization::LocalRun() {
+bool HLoopOptimization::LocalRun() {
+  bool didLoopOpt = false;
   // Build the linear order using the phase-local allocator. This step enables building
   // a loop hierarchy that properly reflects the outer-inner and previous-next relation.
   ScopedArenaVector<HBasicBlock*> linear_order(loop_allocator_->Adapter(kArenaAllocLinearOrder));
@@ -666,7 +669,7 @@ void HLoopOptimization::LocalRun() {
     vector_map_ = &map;
     vector_permanent_map_ = &perm;
     // Traverse.
-    TraverseLoopsInnerToOuter(top_loop_);
+    didLoopOpt = TraverseLoopsInnerToOuter(top_loop_);
     // Detach.
     iset_ = nullptr;
     reductions_ = nullptr;
@@ -674,6 +677,7 @@ void HLoopOptimization::LocalRun() {
     vector_map_ = nullptr;
     vector_permanent_map_ = nullptr;
   }
+  return didLoopOpt;
 }
 
 void HLoopOptimization::AddLoop(HLoopInformation* loop_info) {
-- 
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