v8/src/field-index-inl.h
Jakob Kummerow 455200e009 [cleanup] Move some stuff out of objects-inl.h
HeapObject::SizeFromMap() was too large to get inlined anyway.
HeapObject::IsFoo() predicates should be implemented in foo-inl.h,
because that's what they depend on.
This patch also fixes up includes: dropping unnecessary ones from
object-inl.h, and adding them in other places that previously
relied on getting them transitively.

Bug: v8:8562
Change-Id: Id062bed67257d9dc1899f2d71f44cf69a1368c83
Reviewed-on: https://chromium-review.googlesource.com/c/1450778
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59478}
2019-02-09 00:34:12 +00:00

74 lines
2.8 KiB
C++

// Copyright 2014 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.
#ifndef V8_FIELD_INDEX_INL_H_
#define V8_FIELD_INDEX_INL_H_
#include "src/field-index.h"
#include "src/objects-inl.h"
#include "src/objects/descriptor-array-inl.h"
namespace v8 {
namespace internal {
FieldIndex FieldIndex::ForInObjectOffset(int offset, Encoding encoding) {
DCHECK_IMPLIES(encoding == kWord32, IsAligned(offset, kInt32Size));
DCHECK_IMPLIES(encoding == kTagged, IsAligned(offset, kTaggedSize));
DCHECK_IMPLIES(encoding == kDouble, IsAligned(offset, kDoubleSize));
return FieldIndex(true, offset, encoding, 0, 0);
}
FieldIndex FieldIndex::ForPropertyIndex(const Map map, int property_index,
Representation representation) {
DCHECK(map->instance_type() >= FIRST_NONSTRING_TYPE);
int inobject_properties = map->GetInObjectProperties();
bool is_inobject = property_index < inobject_properties;
int first_inobject_offset;
int offset;
if (is_inobject) {
first_inobject_offset = map->GetInObjectPropertyOffset(0);
offset = map->GetInObjectPropertyOffset(property_index);
} else {
first_inobject_offset = FixedArray::kHeaderSize;
property_index -= inobject_properties;
offset = PropertyArray::OffsetOfElementAt(property_index);
}
Encoding encoding = FieldEncoding(representation);
return FieldIndex(is_inobject, offset, encoding, inobject_properties,
first_inobject_offset);
}
// Returns the index format accepted by the HLoadFieldByIndex instruction.
// (In-object: zero-based from (object start + JSObject::kHeaderSize),
// out-of-object: zero-based from FixedArray::kHeaderSize.)
int FieldIndex::GetLoadByFieldIndex() const {
// For efficiency, the LoadByFieldIndex instruction takes an index that is
// optimized for quick access. If the property is inline, the index is
// positive. If it's out-of-line, the encoded index is -raw_index - 1 to
// disambiguate the zero out-of-line index from the zero inobject case.
// The index itself is shifted up by one bit, the lower-most bit
// signifying if the field is a mutable double box (1) or not (0).
int result = index();
if (is_inobject()) {
result -= JSObject::kHeaderSize / kTaggedSize;
} else {
result -= FixedArray::kHeaderSize / kTaggedSize;
result = -result - 1;
}
result = static_cast<uint32_t>(result) << 1;
return is_double() ? (result | 1) : result;
}
FieldIndex FieldIndex::ForDescriptor(const Map map, int descriptor_index) {
PropertyDetails details =
map->instance_descriptors()->GetDetails(descriptor_index);
int field_index = details.field_index();
return ForPropertyIndex(map, field_index, details.representation());
}
} // namespace internal
} // namespace v8
#endif // V8_FIELD_INDEX_INL_H_