Turn array index dehoisting into a proper HPhase.

R=mvstanton@chromium.org

Review URL: https://codereview.chromium.org/18562009

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15627 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/hydrogen-dehoist.cc

+// 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-dehoist.h"
+
+namespace v8 {
+namespace internal {
+
+static void DehoistArrayIndex(ArrayInstructionInterface* array_operation) {
+  HValue* index = array_operation->GetKey()->ActualValue();
+  if (!index->representation().IsSmiOrInteger32()) return;
+  if (!index->IsAdd() && !index->IsSub()) return;
+
+  HConstant* constant;
+  HValue* subexpression;
+  HBinaryOperation* binary_operation = HBinaryOperation::cast(index);
+  if (binary_operation->left()->IsConstant()) {
+    subexpression = binary_operation->right();
+    constant = HConstant::cast(binary_operation->left());
+  } else if (binary_operation->right()->IsConstant()) {
+    subexpression = binary_operation->left();
+    constant = HConstant::cast(binary_operation->right());
+  } else {
+    return;
+  }
+
+  if (!constant->HasInteger32Value()) return;
+  int32_t sign = binary_operation->IsSub() ? -1 : 1;
+  int32_t value = constant->Integer32Value() * sign;
+  // We limit offset values to 30 bits because we want to avoid the risk of
+  // overflows when the offset is added to the object header size.
+  if (value >= 1 << 30 || value < 0) return;
+  array_operation->SetKey(subexpression);
+  if (binary_operation->HasNoUses()) {
+    binary_operation->DeleteAndReplaceWith(NULL);
+  }
+  array_operation->SetIndexOffset(static_cast<uint32_t>(value));
+  array_operation->SetDehoisted(true);
+}
+
+
+void HDehoistIndexComputationsPhase::Run() {
+  const ZoneList<HBasicBlock*>* blocks(graph()->blocks());
+  for (int i = 0; i < blocks->length(); ++i) {
+    for (HInstructionIterator it(blocks->at(i)); !it.Done(); it.Advance()) {
+      HInstruction* instr = it.Current();
+      if (instr->IsLoadKeyed()) {
+        DehoistArrayIndex(HLoadKeyed::cast(instr));
+      } else if (instr->IsStoreKeyed()) {
+        DehoistArrayIndex(HStoreKeyed::cast(instr));
+      }
+    }
+  }
+}
+
+} }  // namespace v8::internal

src/hydrogen-dehoist.h

+// 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_DEHOIST_H_
+#define V8_HYDROGEN_DEHOIST_H_
+
+#include "hydrogen.h"
+
+namespace v8 {
+namespace internal {
+
+
+class HDehoistIndexComputationsPhase : public HPhase {
+ public:
+  explicit HDehoistIndexComputationsPhase(HGraph* graph)
+      : HPhase("H_Dehoist index computations", graph) { }
+
+  void Run();
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(HDehoistIndexComputationsPhase);
+};
+
+
+} }  // namespace v8::internal
+
+#endif  // V8_HYDROGEN_DEHOIST_H_

src/hydrogen.cc

@@ -36,6 +36,7 @@
 #include "hydrogen-bce.h"
 #include "hydrogen-canonicalize.h"
 #include "hydrogen-dce.h"
+#include "hydrogen-dehoist.h"
 #include "hydrogen-environment-liveness.h"
 #include "hydrogen-escape-analysis.h"
 #include "hydrogen-infer-representation.h"
@@ -3078,7 +3079,7 @@ bool HGraph::Optimize(SmartArrayPointer<char>* bailout_reason) {
   if (FLAG_array_bounds_checks_elimination && !FLAG_idefs) {
     Run<HBoundsCheckEliminationPhase>();
   }
-  if (FLAG_array_index_dehoisting) DehoistSimpleArrayIndexComputations();
+  if (FLAG_array_index_dehoisting) Run<HDehoistIndexComputationsPhase>();
   if (FLAG_dead_code_elimination) Run<HDeadCodeEliminationPhase>();
 
   RestoreActualValues();
@@ -3131,77 +3132,6 @@ void HGraph::SetupInformativeDefinitions() {
 }
 
 
-static void DehoistArrayIndex(ArrayInstructionInterface* array_operation) {
-  HValue* index = array_operation->GetKey()->ActualValue();
-  if (!index->representation().IsSmiOrInteger32()) return;
-
-  HConstant* constant;
-  HValue* subexpression;
-  int32_t sign;
-  if (index->IsAdd()) {
-    sign = 1;
-    HAdd* add = HAdd::cast(index);
-    if (add->left()->IsConstant()) {
-      subexpression = add->right();
-      constant = HConstant::cast(add->left());
-    } else if (add->right()->IsConstant()) {
-      subexpression = add->left();
-      constant = HConstant::cast(add->right());
-    } else {
-      return;
-    }
-  } else if (index->IsSub()) {
-    sign = -1;
-    HSub* sub = HSub::cast(index);
-    if (sub->left()->IsConstant()) {
-      subexpression = sub->right();
-      constant = HConstant::cast(sub->left());
-    } else if (sub->right()->IsConstant()) {
-      subexpression = sub->left();
-      constant = HConstant::cast(sub->right());
-    } else {
-      return;
-    }
-  } else {
-    return;
-  }
-
-  if (!constant->HasInteger32Value()) return;
-  int32_t value = constant->Integer32Value() * sign;
-  // We limit offset values to 30 bits because we want to avoid the risk of
-  // overflows when the offset is added to the object header size.
-  if (value >= 1 << 30 || value < 0) return;
-  array_operation->SetKey(subexpression);
-  if (index->HasNoUses()) {
-    index->DeleteAndReplaceWith(NULL);
-  }
-  ASSERT(value >= 0);
-  array_operation->SetIndexOffset(static_cast<uint32_t>(value));
-  array_operation->SetDehoisted(true);
-}
-
-
-void HGraph::DehoistSimpleArrayIndexComputations() {
-  HPhase phase("H_Dehoist index computations", this);
-  for (int i = 0; i < blocks()->length(); ++i) {
-    for (HInstructionIterator it(blocks()->at(i)); !it.Done(); it.Advance()) {
-      HInstruction* instr = it.Current();
-      ArrayInstructionInterface* array_instruction = NULL;
-      if (instr->IsLoadKeyed()) {
-        HLoadKeyed* op = HLoadKeyed::cast(instr);
-        array_instruction = static_cast<ArrayInstructionInterface*>(op);
-      } else if (instr->IsStoreKeyed()) {
-        HStoreKeyed* op = HStoreKeyed::cast(instr);
-        array_instruction = static_cast<ArrayInstructionInterface*>(op);
-      } else {
-        continue;
-      }
-      DehoistArrayIndex(array_instruction);
-    }
-  }
-}
-
-
 void HGraph::RestoreActualValues() {
   HPhase phase("H_Restore actual values", this);
 

tools/gyp/v8.gyp

@@ -341,6 +341,8 @@
         '../../src/hydrogen-canonicalize.h',
         '../../src/hydrogen-dce.cc',
         '../../src/hydrogen-dce.h',
+        '../../src/hydrogen-dehoist.cc',
+        '../../src/hydrogen-dehoist.h',
         '../../src/hydrogen-environment-liveness.cc',
         '../../src/hydrogen-environment-liveness.h',
         '../../src/hydrogen-escape-analysis.cc',