First simplistic implementation of escape analysis.

src/hydrogen-escape-analysis.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
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 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
 //       with the distribution.
 //     * Neither the name of Google Inc. nor the names of its
 //       contributors may be used to endorse or promote products derived
 //       from this software without specific prior written permission.
 //
 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-#ifndef V8_MARKING_THREAD_H_
-#define V8_MARKING_THREAD_H_
-
-#include "atomicops.h"
-#include "flags.h"
-#include "platform.h"
-#include "v8utils.h"
-
-#include "spaces.h"
-
-#include "heap.h"
+#include "hydrogen-escape-analysis.h"
 
 namespace v8 {
 namespace internal {
 
-class MarkingThread : public Thread {
- public:
-  explicit MarkingThread(Isolate* isolate);
 
-  void Run();
-  void Stop();
-  void StartMarking();
-  void WaitForMarkingThread();
+void HEscapeAnalysis::CollectIfNoEscapingUses(HInstruction* instr) {
+  for (HUseIterator it(instr->uses()); !it.Done(); it.Advance()) {
+    HValue* use = it.value();
+    if (use->HasEscapingOperandAt(it.index())) {
+      if (FLAG_trace_escape_analysis) {
+        PrintF("#%d (%s) escapes through #%d (%s) @%d\n", instr->id(),
+               instr->Mnemonic(), use->id(), use->Mnemonic(), it.index());
+      }
+      return;
+    }
+  }
+  if (FLAG_trace_escape_analysis) {
+    PrintF("#%d (%s) is being captured\n", instr->id(), instr->Mnemonic());
+  }
+  captured_.Add(instr, zone_);
+}
 
-  ~MarkingThread() {
-    delete start_marking_semaphore_;
-    delete end_marking_semaphore_;
-    delete stop_semaphore_;
+
+void HEscapeAnalysis::CollectCapturedValues() {
+  int block_count = graph_->blocks()->length();
+  for (int i = 0; i < block_count; ++i) {
+    HBasicBlock* block = graph_->blocks()->at(i);
+    for (HInstructionIterator it(block); !it.Done(); it.Advance()) {
+      HInstruction* instr = it.Current();
+      if (instr->IsAllocate() || instr->IsAllocateObject()) {
+        CollectIfNoEscapingUses(instr);
+      }
+    }
   }
+}
 
- private:
-  Isolate* isolate_;
-  Heap* heap_;
-  Semaphore* start_marking_semaphore_;
-  Semaphore* end_marking_semaphore_;
-  Semaphore* stop_semaphore_;
-  volatile AtomicWord stop_thread_;
-  int id_;
-  static Atomic32 id_counter_;
-};
+
+void HEscapeAnalysis::Analyze() {
+  HPhase phase("H_Escape analysis", graph_);
+  CollectCapturedValues();
+}
+
 
 } }  // namespace v8::internal
-
-#endif  // V8_MARKING_THREAD_H_