[stubs] Optimize LoadGlobalViaContextStub and StoreGlobalViaContextStub.

src/code-stubs-hydrogen.cc

 // Copyright 2012 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/v8.h"
 
 #include "src/bailout-reason.h"
 #include "src/code-stubs.h"
 #include "src/field-index.h"
 #include "src/hydrogen.h"
@@ skipping 1596 matching lines @@
   return value;
 }
 
 
 Handle<Code> StoreGlobalStub::GenerateCode() {
   return DoGenerateCode(this);
 }
 
 
 template <>
-HValue* CodeStubGraphBuilder<LoadGlobalViaContextStub>::BuildCodeStub() {
-  LoadGlobalViaContextStub* stub = casted_stub();
-  int depth_value = stub->depth();
-  HValue* depth = GetParameter(0);
-  HValue* slot_index = GetParameter(1);
-  HValue* name = GetParameter(2);
-
-  // Choose between dynamic or static context script fetching versions.
-  depth = depth_value < LoadGlobalViaContextStub::kDynamicDepth
-              ? nullptr
-              : AddUncasted<HForceRepresentation>(depth, Representation::Smi());
-  slot_index =
-      AddUncasted<HForceRepresentation>(slot_index, Representation::Smi());
-
-  HValue* script_context = BuildGetParentContext(depth, depth_value);
-  HValue* cell =
-      Add<HLoadKeyed>(script_context, slot_index, nullptr, FAST_ELEMENTS);
-
-  HValue* value = Add<HLoadNamedField>(cell, nullptr,
-                                       HObjectAccess::ForPropertyCellValue());
-
-  IfBuilder builder(this);
-  HValue* hole_value = graph()->GetConstantHole();
-  builder.IfNot<HCompareObjectEqAndBranch, HValue*>(value, hole_value);
-  builder.Then();
-  { Push(value); }
-  builder.Else();
-  {
-    Add<HPushArguments>(script_context, slot_index, name);
-    Push(Add<HCallRuntime>(
-        isolate()->factory()->empty_string(),
-        Runtime::FunctionForId(Runtime::kLoadGlobalViaContext), 3));
-  }
-  builder.End();
-  return Pop();
-}
-
-
-Handle<Code> LoadGlobalViaContextStub::GenerateCode() {
-  return DoGenerateCode(this);
-}
-
-
-template <>
-HValue* CodeStubGraphBuilder<StoreGlobalViaContextStub>::BuildCodeStub() {
-  StoreGlobalViaContextStub* stub = casted_stub();
-  int depth_value = stub->depth();
-  HValue* depth = GetParameter(0);
-  HValue* slot_index = GetParameter(1);
-  HValue* name = GetParameter(2);
-  HValue* value = GetParameter(3);
-
-  // Choose between dynamic or static context script fetching versions.
-  depth = depth_value < StoreGlobalViaContextStub::kDynamicDepth
-              ? nullptr
-              : AddUncasted<HForceRepresentation>(depth, Representation::Smi());
-  slot_index =
-      AddUncasted<HForceRepresentation>(slot_index, Representation::Smi());
-
-  HValue* script_context = BuildGetParentContext(depth, depth_value);
-  HValue* cell =
-      Add<HLoadKeyed>(script_context, slot_index, nullptr, FAST_ELEMENTS);
-
-  // Fast case that requires storing to cell.
-  HIfContinuation if_fast_store_continuation(graph()->CreateBasicBlock(),
-                                             graph()->CreateBasicBlock());
-
-  // Fast case that does not require storing to cell.
-  HIfContinuation if_fast_no_store_continuation(graph()->CreateBasicBlock(),
-                                                graph()->CreateBasicBlock());
-
-  // This stub does the same as StoreGlobalStub but in a dynamic manner.
-
-  HValue* cell_contents = Add<HLoadNamedField>(
-      cell, nullptr, HObjectAccess::ForPropertyCellValue());
-
-  IfBuilder if_hole(this);
-  HValue* hole_value = graph()->GetConstantHole();
-  if_hole.IfNot<HCompareObjectEqAndBranch, HValue*>(cell_contents, hole_value);
-  if_hole.Then();
-  {
-    HValue* details = Add<HLoadNamedField>(
-        cell, nullptr, HObjectAccess::ForPropertyCellDetails());
-    HValue* cell_type =
-        BuildDecodeField<PropertyDetails::PropertyCellTypeField>(details);
-
-    // The code below relies on this.
-    STATIC_ASSERT(PropertyCellType::kUndefined < PropertyCellType::kConstant);
-    STATIC_ASSERT(PropertyCellType::kConstant <
-                  PropertyCellType::kConstantType);
-    STATIC_ASSERT(PropertyCellType::kConstant < PropertyCellType::kMutable);
-
-    // Handle all cell type cases.
-    IfBuilder if_not_const(this);
-
-    int cell_type_constant = static_cast<int>(PropertyCellType::kConstant);
-    if_not_const.If<HCompareNumericAndBranch, HValue*>(
-        cell_type, Add<HConstant>(cell_type_constant), Token::GT);
-    if_not_const.Then();
-    {
-      // kConstantType or kMutable.
-      IfBuilder if_const_type(this);
-      int cell_type_constant_type =
-          static_cast<int>(PropertyCellType::kConstantType);
-      if_const_type.If<HCompareNumericAndBranch, HValue*>(
-          cell_type, Add<HConstant>(cell_type_constant_type), Token::EQ);
-      if_const_type.Then();
-      {
-        // Check that either both value and cell_contents are smi or
-        // both have the same map.
-        IfBuilder if_cell_is_smi(this);
-        if_cell_is_smi.If<HIsSmiAndBranch>(cell_contents);
-        if_cell_is_smi.Then();
-        {
-          IfBuilder if_value_is_smi(this);
-          if_value_is_smi.If<HIsSmiAndBranch>(value);
-          if_value_is_smi.Then();
-          {
-            // Both cell_contents and value are smis, do store.
-          }
-          if_value_is_smi.Else();  // Slow case.
-          if_value_is_smi.JoinContinuation(&if_fast_store_continuation);
-        }
-        if_cell_is_smi.Else();
-        {
-          IfBuilder if_value_is_heap_object(this);
-          if_value_is_heap_object.IfNot<HIsSmiAndBranch>(value);
-          if_value_is_heap_object.Then();
-          {
-            // Both cell_contents and value are heap objects, do store.
-            HValue* expected_map = Add<HLoadNamedField>(
-                cell_contents, nullptr, HObjectAccess::ForMap());
-            HValue* map =
-                Add<HLoadNamedField>(value, nullptr, HObjectAccess::ForMap());
-            IfBuilder map_check(this);
-            map_check.If<HCompareObjectEqAndBranch>(expected_map, map);
-            map_check.Then();
-            map_check.Else();  // Slow case.
-            map_check.JoinContinuation(&if_fast_store_continuation);
-
-            // The accessor case is handled by the map check above, since
-            // the value must not have a AccessorPair map.
-          }
-          if_value_is_heap_object.Else();  // Slow case.
-          if_value_is_heap_object.JoinContinuation(&if_fast_store_continuation);
-        }
-        if_cell_is_smi.EndUnreachable();
-      }
-      if_const_type.Else();
-      {
-        // Check that the property kind is kData.
-        HValue* kind = BuildDecodeField<PropertyDetails::KindField>(details);
-        HValue* data_kind_value = Add<HConstant>(kData);
-
-        IfBuilder builder(this);
-        builder.If<HCompareNumericAndBranch, HValue*>(kind, data_kind_value,
-                                                      Token::EQ);
-        builder.Then();
-        builder.Else();  // Slow case.
-        builder.JoinContinuation(&if_fast_store_continuation);
-      }
-      if_const_type.EndUnreachable();
-    }
-    if_not_const.Else();
-    {
-      // kUndefined or kConstant, just check that the value matches.
-      IfBuilder builder(this);
-      builder.If<HCompareObjectEqAndBranch>(cell_contents, value);
-      builder.Then();
-      builder.Else();  // Slow case.
-      builder.JoinContinuation(&if_fast_no_store_continuation);
-    }
-    if_not_const.EndUnreachable();
-  }
-  if_hole.Else();  // Slow case.
-  if_hole.JoinContinuation(&if_fast_store_continuation);
-
-  // Do store for fast case.
-  IfBuilder if_fast_store(this, &if_fast_store_continuation);
-  if_fast_store.Then();
-  {
-    // All checks are done, store the value to the cell.
-    Add<HStoreNamedField>(cell, HObjectAccess::ForPropertyCellValue(), value);
-  }
-  if_fast_store.Else();
-  if_fast_store.JoinContinuation(&if_fast_no_store_continuation);
-
-  // Bailout to runtime call for slow case.
-  IfBuilder if_no_fast_store(this, &if_fast_no_store_continuation);
-  if_no_fast_store.Then();
-  {
-    // Nothing else to do.
-  }
-  if_no_fast_store.Else();
-  {
-    // Slow case, call runtime.
-    HInstruction* lang_mode = Add<HConstant>(casted_stub()->language_mode());
-    Add<HPushArguments>(script_context, slot_index, name, value);
-    Add<HPushArguments>(lang_mode);
-    Add<HCallRuntime>(isolate()->factory()->empty_string(),
-                      Runtime::FunctionForId(Runtime::kStoreGlobalViaContext),
-                      5);
-  }
-  if_no_fast_store.End();
-  return value;
-}
-
-
-Handle<Code> StoreGlobalViaContextStub::GenerateCode() {
-  return DoGenerateCode(this);
-}
-
-
-template <>
 HValue* CodeStubGraphBuilder<ElementsTransitionAndStoreStub>::BuildCodeStub() {
   HValue* value = GetParameter(ElementsTransitionAndStoreStub::kValueIndex);
   HValue* map = GetParameter(ElementsTransitionAndStoreStub::kMapIndex);
   HValue* key = GetParameter(ElementsTransitionAndStoreStub::kKeyIndex);
   HValue* object = GetParameter(ElementsTransitionAndStoreStub::kObjectIndex);
 
   if (FLAG_trace_elements_transitions) {
     // Tracing elements transitions is the job of the runtime.
     Add<HDeoptimize>(Deoptimizer::kTracingElementsTransitions,
                      Deoptimizer::EAGER);
@@ skipping 646 matching lines @@
   return Pop();
 }
 
 
 Handle<Code> KeyedLoadGenericStub::GenerateCode() {
   return DoGenerateCode(this);
 }
 
 }  // namespace internal
 }  // namespace v8