bdead275bb
R=mvstanton@chromium.org Review URL: https://codereview.chromium.org/528773002 git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@23566 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
130 lines
4.2 KiB
C++
130 lines
4.2 KiB
C++
// Copyright 2014 the V8 project authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#ifndef V8_FIELD_INDEX_INL_H_
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#define V8_FIELD_INDEX_INL_H_
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#include "src/field-index.h"
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namespace v8 {
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namespace internal {
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inline FieldIndex FieldIndex::ForInObjectOffset(int offset, Map* map) {
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DCHECK((offset % kPointerSize) == 0);
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int index = offset / kPointerSize;
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if (map == NULL) {
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return FieldIndex(true, index, false, index + 1, 0, true);
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}
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int first_inobject_offset = map->GetInObjectPropertyOffset(0);
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if (offset < first_inobject_offset) {
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return FieldIndex(true, index, false, 0, 0, true);
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} else {
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return FieldIndex::ForPropertyIndex(map, offset / kPointerSize);
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}
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}
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inline FieldIndex FieldIndex::ForPropertyIndex(Map* map,
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int property_index,
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bool is_double) {
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DCHECK(map->instance_type() >= FIRST_NONSTRING_TYPE);
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int inobject_properties = map->inobject_properties();
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bool is_inobject = property_index < inobject_properties;
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int first_inobject_offset;
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if (is_inobject) {
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first_inobject_offset = map->GetInObjectPropertyOffset(0);
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} else {
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first_inobject_offset = FixedArray::kHeaderSize;
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property_index -= inobject_properties;
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}
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return FieldIndex(is_inobject,
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property_index + first_inobject_offset / kPointerSize,
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is_double, inobject_properties, first_inobject_offset);
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}
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// Takes an index as computed by GetLoadFieldByIndex and reconstructs a
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// FieldIndex object from it.
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inline FieldIndex FieldIndex::ForLoadByFieldIndex(Map* map, int orig_index) {
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int field_index = orig_index;
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int is_inobject = true;
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bool is_double = field_index & 1;
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int first_inobject_offset = 0;
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field_index >>= 1;
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if (field_index < 0) {
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field_index = -(field_index + 1);
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is_inobject = false;
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first_inobject_offset = FixedArray::kHeaderSize;
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field_index += FixedArray::kHeaderSize / kPointerSize;
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} else {
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first_inobject_offset = map->GetInObjectPropertyOffset(0);
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field_index += JSObject::kHeaderSize / kPointerSize;
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}
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FieldIndex result(is_inobject, field_index, is_double,
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map->inobject_properties(), first_inobject_offset);
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DCHECK(result.GetLoadByFieldIndex() == orig_index);
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return result;
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}
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// Returns the index format accepted by the HLoadFieldByIndex instruction.
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// (In-object: zero-based from (object start + JSObject::kHeaderSize),
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// out-of-object: zero-based from FixedArray::kHeaderSize.)
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inline int FieldIndex::GetLoadByFieldIndex() const {
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// For efficiency, the LoadByFieldIndex instruction takes an index that is
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// optimized for quick access. If the property is inline, the index is
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// positive. If it's out-of-line, the encoded index is -raw_index - 1 to
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// disambiguate the zero out-of-line index from the zero inobject case.
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// The index itself is shifted up by one bit, the lower-most bit
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// signifying if the field is a mutable double box (1) or not (0).
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int result = index();
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if (is_inobject()) {
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result -= JSObject::kHeaderSize / kPointerSize;
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} else {
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result -= FixedArray::kHeaderSize / kPointerSize;
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result = -result - 1;
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}
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result <<= 1;
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return is_double() ? (result | 1) : result;
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}
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inline FieldIndex FieldIndex::ForDescriptor(Map* map, int descriptor_index) {
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PropertyDetails details =
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map->instance_descriptors()->GetDetails(descriptor_index);
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int field_index =
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map->instance_descriptors()->GetFieldIndex(descriptor_index);
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return ForPropertyIndex(map, field_index,
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details.representation().IsDouble());
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}
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inline FieldIndex FieldIndex::ForKeyedLookupCacheIndex(Map* map, int index) {
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if (FLAG_compiled_keyed_generic_loads) {
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return ForLoadByFieldIndex(map, index);
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} else {
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return ForPropertyIndex(map, index);
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}
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}
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inline FieldIndex FieldIndex::FromFieldAccessStubKey(int key) {
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return FieldIndex(key);
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}
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inline int FieldIndex::GetKeyedLookupCacheIndex() const {
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if (FLAG_compiled_keyed_generic_loads) {
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return GetLoadByFieldIndex();
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} else {
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return property_index();
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}
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}
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} } // namespace v8::internal
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#endif
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