Turn the representation changes into a proper HPhase.

R=mvstanton@chromium.org

Review URL: https://codereview.chromium.org/18832002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15541 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/hydrogen-representation-changes.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-representation-changes.h"
+
+namespace v8 {
+namespace internal {
+
+void HRepresentationChangesPhase::InsertRepresentationChangeForUse(
+    HValue* value, HValue* use_value, int use_index, Representation to) {
+  // Insert the representation change right before its use. For phi-uses we
+  // insert at the end of the corresponding predecessor.
+  HInstruction* next = NULL;
+  if (use_value->IsPhi()) {
+    next = use_value->block()->predecessors()->at(use_index)->end();
+  } else {
+    next = HInstruction::cast(use_value);
+  }
+  // For constants we try to make the representation change at compile
+  // time. When a representation change is not possible without loss of
+  // information we treat constants like normal instructions and insert the
+  // change instructions for them.
+  HInstruction* new_value = NULL;
+  bool is_truncating = use_value->CheckFlag(HValue::kTruncatingToInt32);
+  bool allow_undefined_as_nan =
+      use_value->CheckFlag(HValue::kAllowUndefinedAsNaN);
+  if (value->IsConstant()) {
+    HConstant* constant = HConstant::cast(value);
+    // Try to create a new copy of the constant with the new representation.
+    new_value = (is_truncating && to.IsInteger32())
+        ? constant->CopyToTruncatedInt32(graph()->zone())
+        : constant->CopyToRepresentation(to, graph()->zone());
+  }
+
+  if (new_value == NULL) {
+    new_value = new(graph()->zone()) HChange(value, to,
+                                             is_truncating,
+                                             allow_undefined_as_nan);
+  }
+
+  new_value->InsertBefore(next);
+  use_value->SetOperandAt(use_index, new_value);
+}
+
+
+void HRepresentationChangesPhase::InsertRepresentationChangesForValue(
+    HValue* value) {
+  Representation r = value->representation();
+  if (r.IsNone()) return;
+  if (value->HasNoUses()) return;
+
+  for (HUseIterator it(value->uses()); !it.Done(); it.Advance()) {
+    HValue* use_value = it.value();
+    int use_index = it.index();
+    Representation req = use_value->RequiredInputRepresentation(use_index);
+    if (req.IsNone() || req.Equals(r)) continue;
+    InsertRepresentationChangeForUse(value, use_value, use_index, req);
+  }
+  if (value->HasNoUses()) {
+    ASSERT(value->IsConstant());
+    value->DeleteAndReplaceWith(NULL);
+  }
+
+  // The only purpose of a HForceRepresentation is to represent the value
+  // after the (possible) HChange instruction.  We make it disappear.
+  if (value->IsForceRepresentation()) {
+    value->DeleteAndReplaceWith(HForceRepresentation::cast(value)->value());
+  }
+}
+
+
+void HRepresentationChangesPhase::Run() {
+  // Compute truncation flag for phis: Initially assume that all
+  // int32-phis allow truncation and iteratively remove the ones that
+  // are used in an operation that does not allow a truncating
+  // conversion.
+  ZoneList<HPhi*> worklist(8, zone());
+
+  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->representation().IsInteger32()) {
+      phi->SetFlag(HValue::kTruncatingToInt32);
+    }
+  }
+
+  for (int i = 0; i < phi_list->length(); i++) {
+    HPhi* phi = phi_list->at(i);
+    for (HUseIterator it(phi->uses()); !it.Done(); it.Advance()) {
+      // If a Phi is used as a non-truncating int32 or as a double,
+      // clear its "truncating" flag.
+      HValue* use = it.value();
+      Representation input_representation =
+          use->RequiredInputRepresentation(it.index());
+      if (!input_representation.IsInteger32() ||
+          !use->CheckFlag(HValue::kTruncatingToInt32)) {
+        if (FLAG_trace_representation) {
+          PrintF("#%d Phi is not truncating because of #%d %s\n",
+                 phi->id(), it.value()->id(), it.value()->Mnemonic());
+        }
+        phi->ClearFlag(HValue::kTruncatingToInt32);
+        worklist.Add(phi, zone());
+        break;
+      }
+    }
+  }
+
+  while (!worklist.is_empty()) {
+    HPhi* current = worklist.RemoveLast();
+    for (int i = 0; i < current->OperandCount(); ++i) {
+      HValue* input = current->OperandAt(i);
+      if (input->IsPhi() &&
+          input->representation().IsInteger32() &&
+          input->CheckFlag(HValue::kTruncatingToInt32)) {
+        if (FLAG_trace_representation) {
+          PrintF("#%d Phi is not truncating because of #%d %s\n",
+                 input->id(), current->id(), current->Mnemonic());
+        }
+        input->ClearFlag(HValue::kTruncatingToInt32);
+        worklist.Add(HPhi::cast(input), zone());
+      }
+    }
+  }
+
+  const ZoneList<HBasicBlock*>* blocks(graph()->blocks());
+  for (int i = 0; i < blocks->length(); ++i) {
+    // Process phi instructions first.
+    const HBasicBlock* block(blocks->at(i));
+    const ZoneList<HPhi*>* phis = block->phis();
+    for (int j = 0; j < phis->length(); j++) {
+      InsertRepresentationChangesForValue(phis->at(j));
+    }
+
+    // Process normal instructions.
+    for (HInstruction* current = block->first(); current != NULL; ) {
+      HInstruction* next = current->next();
+      InsertRepresentationChangesForValue(current);
+      current = next;
+    }
+  }
+}
+
+} }  // namespace v8::internal

src/hydrogen-representation-changes.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_REPRESENTATION_CHANGES_H_
+#define V8_HYDROGEN_REPRESENTATION_CHANGES_H_
+
+#include "hydrogen.h"
+
+namespace v8 {
+namespace internal {
+
+
+class HRepresentationChangesPhase : public HPhase {
+ public:
+  explicit HRepresentationChangesPhase(HGraph* graph)
+      : HPhase("H_Representation changes", graph) { }
+
+  void Run();
+
+ private:
+  void InsertRepresentationChangeForUse(HValue* value,
+                                        HValue* use_value,
+                                        int use_index,
+                                        Representation to);
+  void InsertRepresentationChangesForValue(HValue* value);
+};
+
+
+} }  // namespace v8::internal
+
+#endif  // V8_HYDROGEN_REPRESENTATION_CHANGES_H_

src/hydrogen.cc

@@ -43,6 +43,7 @@
 #include "hydrogen-osr.h"
 #include "hydrogen-range-analysis.h"
 #include "hydrogen-redundant-phi.h"
+#include "hydrogen-representation-changes.h"
 #include "hydrogen-sce.h"
 #include "hydrogen-uint32-analysis.h"
 #include "lithium-allocator.h"
@@ -2668,141 +2669,6 @@ void HGraph::PropagateMinusZeroChecks(HValue* value, BitVector* visited) {
 }
 
 
-void HGraph::InsertRepresentationChangeForUse(HValue* value,
-                                              HValue* use_value,
-                                              int use_index,
-                                              Representation to) {
-  // Insert the representation change right before its use. For phi-uses we
-  // insert at the end of the corresponding predecessor.
-  HInstruction* next = NULL;
-  if (use_value->IsPhi()) {
-    next = use_value->block()->predecessors()->at(use_index)->end();
-  } else {
-    next = HInstruction::cast(use_value);
-  }
-  // For constants we try to make the representation change at compile
-  // time. When a representation change is not possible without loss of
-  // information we treat constants like normal instructions and insert the
-  // change instructions for them.
-  HInstruction* new_value = NULL;
-  bool is_truncating = use_value->CheckFlag(HValue::kTruncatingToInt32);
-  bool allow_undefined_as_nan =
-      use_value->CheckFlag(HValue::kAllowUndefinedAsNaN);
-  if (value->IsConstant()) {
-    HConstant* constant = HConstant::cast(value);
-    // Try to create a new copy of the constant with the new representation.
-    new_value = (is_truncating && to.IsInteger32())
-        ? constant->CopyToTruncatedInt32(zone())
-        : constant->CopyToRepresentation(to, zone());
-  }
-
-  if (new_value == NULL) {
-    new_value = new(zone()) HChange(value, to,
-                                    is_truncating, allow_undefined_as_nan);
-  }
-
-  new_value->InsertBefore(next);
-  use_value->SetOperandAt(use_index, new_value);
-}
-
-
-void HGraph::InsertRepresentationChangesForValue(HValue* value) {
-  Representation r = value->representation();
-  if (r.IsNone()) return;
-  if (value->HasNoUses()) return;
-
-  for (HUseIterator it(value->uses()); !it.Done(); it.Advance()) {
-    HValue* use_value = it.value();
-    int use_index = it.index();
-    Representation req = use_value->RequiredInputRepresentation(use_index);
-    if (req.IsNone() || req.Equals(r)) continue;
-    InsertRepresentationChangeForUse(value, use_value, use_index, req);
-  }
-  if (value->HasNoUses()) {
-    ASSERT(value->IsConstant());
-    value->DeleteAndReplaceWith(NULL);
-  }
-
-  // The only purpose of a HForceRepresentation is to represent the value
-  // after the (possible) HChange instruction.  We make it disappear.
-  if (value->IsForceRepresentation()) {
-    value->DeleteAndReplaceWith(HForceRepresentation::cast(value)->value());
-  }
-}
-
-
-void HGraph::InsertRepresentationChanges() {
-  HPhase phase("H_Representation changes", this);
-
-  // Compute truncation flag for phis: Initially assume that all
-  // int32-phis allow truncation and iteratively remove the ones that
-  // are used in an operation that does not allow a truncating
-  // conversion.
-  ZoneList<HPhi*> worklist(8, zone());
-
-  for (int i = 0; i < phi_list()->length(); i++) {
-    HPhi* phi = phi_list()->at(i);
-    if (phi->representation().IsInteger32()) {
-      phi->SetFlag(HValue::kTruncatingToInt32);
-    }
-  }
-
-  for (int i = 0; i < phi_list()->length(); i++) {
-    HPhi* phi = phi_list()->at(i);
-    for (HUseIterator it(phi->uses()); !it.Done(); it.Advance()) {
-      // If a Phi is used as a non-truncating int32 or as a double,
-      // clear its "truncating" flag.
-      HValue* use = it.value();
-      Representation input_representation =
-          use->RequiredInputRepresentation(it.index());
-      if (!input_representation.IsInteger32() ||
-          !use->CheckFlag(HValue::kTruncatingToInt32)) {
-        if (FLAG_trace_representation) {
-          PrintF("#%d Phi is not truncating because of #%d %s\n",
-                 phi->id(), it.value()->id(), it.value()->Mnemonic());
-        }
-        phi->ClearFlag(HValue::kTruncatingToInt32);
-        worklist.Add(phi, zone());
-        break;
-      }
-    }
-  }
-
-  while (!worklist.is_empty()) {
-    HPhi* current = worklist.RemoveLast();
-    for (int i = 0; i < current->OperandCount(); ++i) {
-      HValue* input = current->OperandAt(i);
-      if (input->IsPhi() &&
-          input->representation().IsInteger32() &&
-          input->CheckFlag(HValue::kTruncatingToInt32)) {
-        if (FLAG_trace_representation) {
-          PrintF("#%d Phi is not truncating because of #%d %s\n",
-                 input->id(), current->id(), current->Mnemonic());
-        }
-        input->ClearFlag(HValue::kTruncatingToInt32);
-        worklist.Add(HPhi::cast(input), zone());
-      }
-    }
-  }
-
-  for (int i = 0; i < blocks_.length(); ++i) {
-    // Process phi instructions first.
-    const ZoneList<HPhi*>* phis = blocks_[i]->phis();
-    for (int j = 0; j < phis->length(); j++) {
-      InsertRepresentationChangesForValue(phis->at(j));
-    }
-
-    // Process normal instructions.
-    HInstruction* current = blocks_[i]->first();
-    while (current != NULL) {
-      HInstruction* next = current->next();
-      InsertRepresentationChangesForValue(current);
-      current = next;
-    }
-  }
-}
-
-
 void HGraph::RecursivelyMarkPhiDeoptimizeOnUndefined(HPhi* phi) {
   if (!phi->CheckFlag(HValue::kAllowUndefinedAsNaN)) return;
   phi->ClearFlag(HValue::kAllowUndefinedAsNaN);
@@ -3334,7 +3200,7 @@ bool HGraph::Optimize(SmartArrayPointer<char>* bailout_reason) {
   MergeRemovableSimulates();
 
   MarkDeoptimizeOnUndefined();
-  InsertRepresentationChanges();
+  Run<HRepresentationChangesPhase>();
 
   Run<HInferTypesPhase>();
 

src/hydrogen.h

@@ -293,7 +293,6 @@ class HGraph: public ZoneObject {
   void FinalizeUniqueValueIds();
   void InsertTypeConversions();
   void MergeRemovableSimulates();
-  void InsertRepresentationChanges();
   void MarkDeoptimizeOnUndefined();
   void ComputeMinusZeroChecks();
   bool ProcessArgumentsObject();
@@ -452,11 +451,6 @@ class HGraph: public ZoneObject {
   void InsertTypeConversions(HInstruction* instr);
   void PropagateMinusZeroChecks(HValue* value, BitVector* visited);
   void RecursivelyMarkPhiDeoptimizeOnUndefined(HPhi* phi);
-  void InsertRepresentationChangeForUse(HValue* value,
-                                        HValue* use_value,
-                                        int use_index,
-                                        Representation to);
-  void InsertRepresentationChangesForValue(HValue* value);
   void CheckForBackEdge(HBasicBlock* block, HBasicBlock* successor);
   void SetupInformativeDefinitionsInBlock(HBasicBlock* block);
   void SetupInformativeDefinitionsRecursively(HBasicBlock* block);

tools/gyp/v8.gyp

@@ -357,6 +357,8 @@
         '../../src/hydrogen-range-analysis.h',
         '../../src/hydrogen-redundant-phi.cc',
         '../../src/hydrogen-redundant-phi.h',
+        '../../src/hydrogen-representation-changes.cc',
+        '../../src/hydrogen-representation-changes.h',
         '../../src/hydrogen-sce.cc',
         '../../src/hydrogen-sce.h',
         '../../src/hydrogen-uint32-analysis.cc',