Move Hydrogen and Lithium to src/crankshaft/

src/hydrogen-representation-changes.cc

-// Copyright 2013 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "src/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_to_smi = use_value->CheckFlag(HValue::kTruncatingToSmi);
-  bool is_truncating_to_int = use_value->CheckFlag(HValue::kTruncatingToInt32);
-  if (value->IsConstant()) {
-    HConstant* constant = HConstant::cast(value);
-    // Try to create a new copy of the constant with the new representation.
-    if (is_truncating_to_int && to.IsInteger32()) {
-      Maybe<HConstant*> res = constant->CopyToTruncatedInt32(graph()->zone());
-      if (res.IsJust()) new_value = res.FromJust();
-    } else {
-      new_value = constant->CopyToRepresentation(to, graph()->zone());
-    }
-  }
-
-  if (new_value == NULL) {
-    new_value = new(graph()->zone()) HChange(
-        value, to, is_truncating_to_smi, is_truncating_to_int);
-    if (!use_value->operand_position(use_index).IsUnknown()) {
-      new_value->set_position(use_value->operand_position(use_index));
-    } else {
-      DCHECK(!FLAG_hydrogen_track_positions ||
-             !graph()->info()->IsOptimizing());
-    }
-  }
-
-  new_value->InsertBefore(next);
-  use_value->SetOperandAt(use_index, new_value);
-}
-
-
-static bool IsNonDeoptingIntToSmiChange(HChange* change) {
-  Representation from_rep = change->from();
-  Representation to_rep = change->to();
-  // Flags indicating Uint32 operations are set in a later Hydrogen phase.
-  DCHECK(!change->CheckFlag(HValue::kUint32));
-  return from_rep.IsInteger32() && to_rep.IsSmi() && SmiValuesAre32Bits();
-}
-
-
-void HRepresentationChangesPhase::InsertRepresentationChangesForValue(
-    HValue* value) {
-  Representation r = value->representation();
-  if (r.IsNone()) {
-#ifdef DEBUG
-    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);
-      DCHECK(req.IsNone());
-    }
-#endif
-    return;
-  }
-  if (value->HasNoUses()) {
-    if (value->IsForceRepresentation()) value->DeleteAndReplaceWith(NULL);
-    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;
-
-    // If this is an HForceRepresentation instruction, and an HChange has been
-    // inserted above it, examine the input representation of the HChange. If
-    // that's int32, and this HForceRepresentation use is int32, and int32 to
-    // smi changes can't cause deoptimisation, set the input of the use to the
-    // input of the HChange.
-    if (value->IsForceRepresentation()) {
-      HValue* input = HForceRepresentation::cast(value)->value();
-      if (input->IsChange()) {
-        HChange* change = HChange::cast(input);
-        if (change->from().Equals(req) && IsNonDeoptingIntToSmiChange(change)) {
-          use_value->SetOperandAt(use_index, change->value());
-          continue;
-        }
-      }
-    }
-    InsertRepresentationChangeForUse(value, use_value, use_index, req);
-  }
-  if (value->HasNoUses()) {
-    DCHECK(value->IsConstant() || value->IsForceRepresentation());
-    value->DeleteAndReplaceWith(NULL);
-  } else {
-    // 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*> int_worklist(8, zone());
-  ZoneList<HPhi*> smi_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);
-    } else if (phi->representation().IsSmi()) {
-      phi->SetFlag(HValue::kTruncatingToSmi);
-      phi->SetFlag(HValue::kTruncatingToInt32);
-    }
-  }
-
-  for (int i = 0; i < phi_list->length(); i++) {
-    HPhi* phi = phi_list->at(i);
-    HValue* value = NULL;
-    if (phi->representation().IsSmiOrInteger32() &&
-        !phi->CheckUsesForFlag(HValue::kTruncatingToInt32, &value)) {
-      int_worklist.Add(phi, zone());
-      phi->ClearFlag(HValue::kTruncatingToInt32);
-      if (FLAG_trace_representation) {
-        PrintF("#%d Phi is not truncating Int32 because of #%d %s\n",
-               phi->id(), value->id(), value->Mnemonic());
-      }
-    }
-
-    if (phi->representation().IsSmi() &&
-        !phi->CheckUsesForFlag(HValue::kTruncatingToSmi, &value)) {
-      smi_worklist.Add(phi, zone());
-      phi->ClearFlag(HValue::kTruncatingToSmi);
-      if (FLAG_trace_representation) {
-        PrintF("#%d Phi is not truncating Smi because of #%d %s\n",
-               phi->id(), value->id(), value->Mnemonic());
-      }
-    }
-  }
-
-  while (!int_worklist.is_empty()) {
-    HPhi* current = int_worklist.RemoveLast();
-    for (int i = 0; i < current->OperandCount(); ++i) {
-      HValue* input = current->OperandAt(i);
-      if (input->IsPhi() &&
-          input->representation().IsSmiOrInteger32() &&
-          input->CheckFlag(HValue::kTruncatingToInt32)) {
-        if (FLAG_trace_representation) {
-          PrintF("#%d Phi is not truncating Int32 because of #%d %s\n",
-                 input->id(), current->id(), current->Mnemonic());
-        }
-        input->ClearFlag(HValue::kTruncatingToInt32);
-        int_worklist.Add(HPhi::cast(input), zone());
-      }
-    }
-  }
-
-  while (!smi_worklist.is_empty()) {
-    HPhi* current = smi_worklist.RemoveLast();
-    for (int i = 0; i < current->OperandCount(); ++i) {
-      HValue* input = current->OperandAt(i);
-      if (input->IsPhi() &&
-          input->representation().IsSmi() &&
-          input->CheckFlag(HValue::kTruncatingToSmi)) {
-        if (FLAG_trace_representation) {
-          PrintF("#%d Phi is not truncating Smi because of #%d %s\n",
-                 input->id(), current->id(), current->Mnemonic());
-        }
-        input->ClearFlag(HValue::kTruncatingToSmi);
-        smi_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 internal
-}  // namespace v8