Hydrogenized KeyedLoadGeneric stub: Fix FieldIndex::GetLoadByFieldIndex()

R=danno@chromium.org

Review URL: https://codereview.chromium.org/370573003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22238 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
parent 031526c5
......@@ -45,6 +45,8 @@ inline FieldIndex FieldIndex::ForPropertyIndex(Map* map,
}
// Takes an index as computed by GetLoadFieldByIndex and reconstructs a
// FieldIndex object from it.
inline FieldIndex FieldIndex::ForLoadByFieldIndex(Map* map, int orig_index) {
int field_index = orig_index;
int is_inobject = true;
......@@ -60,8 +62,32 @@ inline FieldIndex FieldIndex::ForLoadByFieldIndex(Map* map, int orig_index) {
first_inobject_offset = map->GetInObjectPropertyOffset(0);
field_index += JSObject::kHeaderSize / kPointerSize;
}
return FieldIndex(is_inobject, field_index, is_double,
FieldIndex result(is_inobject, field_index, is_double,
map->inobject_properties(), first_inobject_offset);
ASSERT(result.GetLoadByFieldIndex() == orig_index);
return result;
}
// 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.)
inline 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 / kPointerSize;
} else {
result -= FixedArray::kHeaderSize / kPointerSize;
result = -result - 1;
}
result <<= 1;
return is_double() ? (result | 1) : result;
}
......
......@@ -28,6 +28,8 @@ class FieldIndex V8_FINAL {
static FieldIndex ForLoadByFieldIndex(Map* map, int index);
static FieldIndex ForKeyedLookupCacheIndex(Map* map, int index);
int GetLoadByFieldIndex() const;
bool is_inobject() const {
return IsInObjectBits::decode(bit_field_);
}
......@@ -40,6 +42,7 @@ class FieldIndex V8_FINAL {
return index() * kPointerSize;
}
// Zero-indexed from beginning of the object.
int index() const {
return IndexBits::decode(bit_field_);
}
......@@ -49,6 +52,8 @@ class FieldIndex V8_FINAL {
return index() - first_inobject_property_offset() / kPointerSize;
}
// Zero-based from the first inobject property. Overflows to out-of-object
// properties.
int property_index() const {
ASSERT(!IsHiddenField::decode(bit_field_));
int result = index() - first_inobject_property_offset() / kPointerSize;
......@@ -58,21 +63,6 @@ class FieldIndex V8_FINAL {
return result;
}
int 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() - first_inobject_property_offset() / kPointerSize;
if (!is_inobject()) {
result = -result - 1;
}
result <<= 1;
return is_double() ? (result | 1) : result;
}
int GetKeyedLookupCacheIndex() const;
int GetLoadFieldStubKey() const {
......@@ -100,11 +90,14 @@ class FieldIndex V8_FINAL {
static const int kIndexBitsSize = kDescriptorIndexBitCount + 1;
// Index from beginning of object.
class IndexBits: public BitField<int, 0, kIndexBitsSize> {};
class IsInObjectBits: public BitField<bool, IndexBits::kNext, 1> {};
class IsDoubleBits: public BitField<bool, IsInObjectBits::kNext, 1> {};
// Number of inobject properties.
class InObjectPropertyBits: public BitField<int, IsDoubleBits::kNext,
kDescriptorIndexBitCount> {};
// Offset of first inobject property from beginning of object.
class FirstInobjectPropertyOffsetBits:
public BitField<int, InObjectPropertyBits::kNext, 7> {};
class IsHiddenField:
......
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