Turn mark deoptimize on undefined into a proper HPhase.

This patch also removes the implicit recursion on phi operands,
using a loop and a worklist instead, to avoid potential stack
overflows.

R=dslomov@chromium.org

Review URL: https://codereview.chromium.org/21065003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15952 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/hydrogen-mark-deoptimize.cc

@@ -0,0 +1,71 @@
+// Copyright 2013 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// 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,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "hydrogen-mark-deoptimize.h"
+
+namespace v8 {
+namespace internal {
+
+void HMarkDeoptimizeOnUndefinedPhase::Run() {
+  const ZoneList<HPhi*>* phi_list = graph()->phi_list();
+  for (int i = 0; i < phi_list->length(); i++) {
+    HPhi* phi = phi_list->at(i);
+    if (phi->CheckFlag(HValue::kAllowUndefinedAsNaN)) {
+      for (HUseIterator it(phi->uses()); !it.Done(); it.Advance()) {
+        HValue* use_value = it.value();
+        if (!use_value->CheckFlag(HValue::kAllowUndefinedAsNaN)) {
+          ProcessPhi(phi);
+          break;
+        }
+      }
+    }
+  }
+}
+
+
+void HMarkDeoptimizeOnUndefinedPhase::ProcessPhi(HPhi* phi) {
+  ASSERT(phi->CheckFlag(HValue::kAllowUndefinedAsNaN));
+  ASSERT(worklist_.is_empty());
+
+  // Push the phi onto the worklist
+  phi->ClearFlag(HValue::kAllowUndefinedAsNaN);
+  worklist_.Add(phi, zone());
+
+  // Process all phis that can reach this phi
+  while (!worklist_.is_empty()) {
+    phi = worklist_.RemoveLast();
+    for (int i = phi->OperandCount() - 1; i >= 0; --i) {
+      HValue* input = phi->OperandAt(i);
+      if (input->IsPhi() && input->CheckFlag(HValue::kAllowUndefinedAsNaN)) {
+        input->ClearFlag(HValue::kAllowUndefinedAsNaN);
+        worklist_.Add(HPhi::cast(input), zone());
+      }
+    }
+  }
+}
+
+} }  // namespace v8::internal

src/hydrogen-mark-deoptimize.h

@@ -0,0 +1,63 @@
+// Copyright 2013 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// 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,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef V8_HYDROGEN_MARK_DEOPTIMIZE_H_
+#define V8_HYDROGEN_MARK_DEOPTIMIZE_H_
+
+#include "hydrogen.h"
+
+namespace v8 {
+namespace internal {
+
+
+// Compute DeoptimizeOnUndefined flag for phis.  Any phi that can reach a use
+// with DeoptimizeOnUndefined set must have DeoptimizeOnUndefined set.
+// Currently only HCompareNumericAndBranch, with double input representation,
+// has this flag set.  The flag is used by HChange tagged->double, which must
+// deoptimize if one of its uses has this flag set.
+class HMarkDeoptimizeOnUndefinedPhase : public HPhase {
+ public:
+  explicit HMarkDeoptimizeOnUndefinedPhase(HGraph* graph)
+      : HPhase("H_Mark deoptimize on undefined", graph),
+        worklist_(16, zone()) {}
+
+  void Run();
+
+ private:
+  void ProcessPhi(HPhi* phi);
+
+  // Preallocated worklist used as an optimization so we don't have
+  // to allocate a new ZoneList for every ProcessPhi() invocation.
+  ZoneList<HPhi*> worklist_;
+
+  DISALLOW_COPY_AND_ASSIGN(HMarkDeoptimizeOnUndefinedPhase);
+};
+
+
+} }  // namespace v8::internal
+
+#endif  // V8_HYDROGEN_MARK_DEOPTIMIZE_H_

src/hydrogen.cc

@@ -44,6 +44,7 @@
 #include "hydrogen-infer-representation.h"
 #include "hydrogen-infer-types.h"
 #include "hydrogen-gvn.h"
+#include "hydrogen-mark-deoptimize.h"
 #include "hydrogen-minus-zero.h"
 #include "hydrogen-osr.h"
 #include "hydrogen-range-analysis.h"
@@ -2514,38 +2515,6 @@ void HGraph::CollectPhis() {
 }
 
 
-void HGraph::RecursivelyMarkPhiDeoptimizeOnUndefined(HPhi* phi) {
-  if (!phi->CheckFlag(HValue::kAllowUndefinedAsNaN)) return;
-  phi->ClearFlag(HValue::kAllowUndefinedAsNaN);
-  for (int i = 0; i < phi->OperandCount(); ++i) {
-    HValue* input = phi->OperandAt(i);
-    if (input->IsPhi()) {
-      RecursivelyMarkPhiDeoptimizeOnUndefined(HPhi::cast(input));
-    }
-  }
-}
-
-
-void HGraph::MarkDeoptimizeOnUndefined() {
-  HPhase phase("H_MarkDeoptimizeOnUndefined", this);
-  // Compute DeoptimizeOnUndefined flag for phis.  Any phi that can reach a use
-  // with DeoptimizeOnUndefined set must have DeoptimizeOnUndefined set.
-  // Currently only HCompareNumericAndBranch, with double input representation,
-  // has this flag set.  The flag is used by HChange tagged->double, which must
-  // deoptimize if one of its uses has this flag set.
-  for (int i = 0; i < phi_list()->length(); i++) {
-    HPhi* phi = phi_list()->at(i);
-    for (HUseIterator it(phi->uses()); !it.Done(); it.Advance()) {
-      HValue* use_value = it.value();
-      if (!use_value->CheckFlag(HValue::kAllowUndefinedAsNaN)) {
-        RecursivelyMarkPhiDeoptimizeOnUndefined(phi);
-        break;
-      }
-    }
-  }
-}
-
-
 // Implementation of utility class to encapsulate the translation state for
 // a (possibly inlined) function.
 FunctionState::FunctionState(HOptimizedGraphBuilder* owner,
@@ -3018,7 +2987,7 @@ bool HGraph::Optimize(SmartArrayPointer<char>* bailout_reason) {
   // This must happen after inferring representations.
   Run<HMergeRemovableSimulatesPhase>();
 
-  MarkDeoptimizeOnUndefined();
+  Run<HMarkDeoptimizeOnUndefinedPhase>();
   Run<HRepresentationChangesPhase>();
 
   Run<HInferTypesPhase>();

src/hydrogen.h

@@ -316,7 +316,6 @@ class HGraph: public ZoneObject {
   HEnvironment* start_environment() const { return start_environment_; }
 
   void FinalizeUniqueValueIds();
-  void MarkDeoptimizeOnUndefined();
   bool ProcessArgumentsObject();
   void OrderBlocks();
   void AssignDominators();
@@ -464,7 +463,6 @@ class HGraph: public ZoneObject {
     phase.Run();
   }
 
-  void RecursivelyMarkPhiDeoptimizeOnUndefined(HPhi* phi);
   void CheckForBackEdge(HBasicBlock* block, HBasicBlock* successor);
   void SetupInformativeDefinitionsInBlock(HBasicBlock* block);
   void SetupInformativeDefinitionsRecursively(HBasicBlock* block);

tools/gyp/v8.gyp

@@ -361,6 +361,8 @@
         '../../src/hydrogen-infer-representation.h',
         '../../src/hydrogen-infer-types.cc',
         '../../src/hydrogen-infer-types.h',
+        '../../src/hydrogen-mark-deoptimize.cc',
+        '../../src/hydrogen-mark-deoptimize.h',
         '../../src/hydrogen-minus-zero.cc',
         '../../src/hydrogen-minus-zero.h',
         '../../src/hydrogen-range-analysis.cc',