Revision: 20039
Author: [email protected]
Date: Tue Mar 18 15:01:55 2014 UTC
Log: A64: ElementsKind TODOs
Replace LoadElementsKind with LoadElementsKindFromMap, remove unneeded TODO
in
DoStringCharFromCode, improve constraints for DoCheckValue and improve code
for
ElementsKind checking in StoreArrayLiteralElementStub.
BUG=
[email protected]
Review URL: https://codereview.chromium.org/202853005
http://code.google.com/p/v8/source/detail?r=20039
Modified:
/branches/bleeding_edge/src/a64/code-stubs-a64.cc
/branches/bleeding_edge/src/a64/lithium-a64.cc
/branches/bleeding_edge/src/a64/lithium-a64.h
/branches/bleeding_edge/src/a64/lithium-codegen-a64.cc
/branches/bleeding_edge/src/a64/macro-assembler-a64.cc
/branches/bleeding_edge/src/a64/macro-assembler-a64.h
=======================================
--- /branches/bleeding_edge/src/a64/code-stubs-a64.cc Tue Mar 18 14:00:21
2014 UTC
+++ /branches/bleeding_edge/src/a64/code-stubs-a64.cc Tue Mar 18 15:01:55
2014 UTC
@@ -4791,12 +4791,6 @@
void StoreArrayLiteralElementStub::Generate(MacroAssembler* masm) {
- // TODO(all): Possible optimisations in this function:
- // 1. Merge CheckFastElements and CheckFastSmiElements, so that the map
- // bitfield is loaded only once.
- // 2. Refactor the Ldr/Add sequence at the start of fast_elements and
- // smi_element.
-
// x0 value element value to store
// x3 index_smi element index as smi
// sp[0] array_index_smi array literal index in function as smi
@@ -4812,9 +4806,23 @@
__ Ldr(array_map, FieldMemOperand(array, JSObject::kMapOffset));
Label double_elements, smi_element, fast_elements, slow_elements;
- __ CheckFastElements(array_map, x10, &double_elements);
+ Register bitfield2 = x10;
+ __ Ldrb(bitfield2, FieldMemOperand(array_map, Map::kBitField2Offset));
+
+ // Jump if array's ElementsKind is not FAST*_SMI_ELEMENTS, FAST_ELEMENTS
or
+ // FAST_HOLEY_ELEMENTS.
+ STATIC_ASSERT(FAST_SMI_ELEMENTS == 0);
+ STATIC_ASSERT(FAST_HOLEY_SMI_ELEMENTS == 1);
+ STATIC_ASSERT(FAST_ELEMENTS == 2);
+ STATIC_ASSERT(FAST_HOLEY_ELEMENTS == 3);
+ __ Cmp(bitfield2, Map::kMaximumBitField2FastHoleyElementValue);
+ __ B(hi, &double_elements);
+
__ JumpIfSmi(value, &smi_element);
- __ CheckFastSmiElements(array_map, x10, &fast_elements);
+
+ // Jump if array's ElementsKind is not FAST_ELEMENTS or
FAST_HOLEY_ELEMENTS.
+ __ Tbnz(bitfield2, MaskToBit(FAST_ELEMENTS << Map::kElementsKindShift),
+ &fast_elements);
// Store into the array literal requires an elements transition. Call
into
// the runtime.
@@ -5540,12 +5548,8 @@
__ Ldr(x10, FieldMemOperand(constructor,
JSFunction::kPrototypeOrInitialMapOffset));
- // TODO(jbramley): Add a helper function to read elements kind from an
- // existing map.
- // Load the map's "bit field 2" into result.
- __ Ldr(kind, FieldMemOperand(x10, Map::kBitField2Offset));
- // Retrieve elements_kind from bit field 2.
- __ Ubfx(kind, kind, Map::kElementsKindShift, Map::kElementsKindBitCount);
+ // Retrieve elements_kind from map.
+ __ LoadElementsKindFromMap(kind, x10);
if (FLAG_debug_code) {
Label done;
=======================================
--- /branches/bleeding_edge/src/a64/lithium-a64.cc Thu Mar 13 14:56:57 2014
UTC
+++ /branches/bleeding_edge/src/a64/lithium-a64.cc Tue Mar 18 15:01:55 2014
UTC
@@ -1176,12 +1176,8 @@
LInstruction* LChunkBuilder::DoCheckValue(HCheckValue* instr) {
- // We only need a temp register if the target is in new space, but we
can't
- // dereference the handle to test that here.
- // TODO(all): Check these constraints. The temp register is not always
used.
- LOperand* value = UseRegister(instr->value());
- LOperand* temp = TempRegister();
- return AssignEnvironment(new(zone()) LCheckValue(value, temp));
+ LOperand* value = UseRegisterAtStart(instr->value());
+ return AssignEnvironment(new(zone()) LCheckValue(value));
}
@@ -2292,7 +2288,6 @@
LInstruction* LChunkBuilder::DoStringCharFromCode(HStringCharFromCode*
instr) {
- // TODO(all) use at start and remove assert in codegen
LOperand* char_code = UseRegister(instr->value());
LOperand* context = UseAny(instr->context());
LStringCharFromCode* result =
@@ -2320,7 +2315,7 @@
ASSERT(instr->right()->representation().Equals(instr->representation()));
LOperand *left;
if (instr->left()->IsConstant() &&
- (HConstant::cast(instr->left())->Integer32Value() == 0)) {
+ (HConstant::cast(instr->left())->Integer32Value() == 0)) {
left = UseConstant(instr->left());
} else {
left = UseRegisterAtStart(instr->left());
=======================================
--- /branches/bleeding_edge/src/a64/lithium-a64.h Thu Mar 13 13:18:48 2014
UTC
+++ /branches/bleeding_edge/src/a64/lithium-a64.h Tue Mar 18 15:01:55 2014
UTC
@@ -965,15 +965,13 @@
};
-class LCheckValue V8_FINAL : public LTemplateInstruction<0, 1, 1> {
+class LCheckValue V8_FINAL : public LTemplateInstruction<0, 1, 0> {
public:
- LCheckValue(LOperand* value, LOperand* temp) {
+ explicit LCheckValue(LOperand* value) {
inputs_[0] = value;
- temps_[0] = temp;
}
LOperand* value() { return inputs_[0]; }
- LOperand* temp() { return temps_[0]; }
DECLARE_CONCRETE_INSTRUCTION(CheckValue, "check-value")
DECLARE_HYDROGEN_ACCESSOR(CheckValue)
=======================================
--- /branches/bleeding_edge/src/a64/lithium-codegen-a64.cc Tue Mar 18
14:26:26 2014 UTC
+++ /branches/bleeding_edge/src/a64/lithium-codegen-a64.cc Tue Mar 18
15:01:55 2014 UTC
@@ -2538,7 +2538,8 @@
Handle<HeapObject> object = instr->hydrogen()->object().handle();
AllowDeferredHandleDereference smi_check;
if (isolate()->heap()->InNewSpace(*object)) {
- Register temp = ToRegister(instr->temp());
+ UseScratchRegisterScope temps(masm());
+ Register temp = temps.AcquireX();
Handle<Cell> cell = isolate()->factory()->NewCell(object);
__ Mov(temp, Operand(Handle<Object>(cell)));
__ Ldr(temp, FieldMemOperand(temp, Cell::kValueOffset));
=======================================
--- /branches/bleeding_edge/src/a64/macro-assembler-a64.cc Tue Mar 18
14:00:21 2014 UTC
+++ /branches/bleeding_edge/src/a64/macro-assembler-a64.cc Tue Mar 18
15:01:55 2014 UTC
@@ -3678,11 +3678,9 @@
}
-void MacroAssembler::LoadElementsKind(Register result, Register object) {
- // Load map.
- __ Ldr(result, FieldMemOperand(object, HeapObject::kMapOffset));
+void MacroAssembler::LoadElementsKindFromMap(Register result, Register
map) {
// Load the map's "bit field 2".
- __ Ldrb(result, FieldMemOperand(result, Map::kBitField2Offset));
+ __ Ldrb(result, FieldMemOperand(map, Map::kBitField2Offset));
// Retrieve elements_kind from bit field 2.
__ Ubfx(result, result, Map::kElementsKindShift,
Map::kElementsKindBitCount);
}
@@ -3838,17 +3836,6 @@
Operand(Map::kMaximumBitField2FastHoleyElementValue), CFlag, hi);
B(hi, fail);
}
-
-
-void MacroAssembler::CheckFastSmiElements(Register map,
- Register scratch,
- Label* fail) {
- STATIC_ASSERT(FAST_SMI_ELEMENTS == 0);
- STATIC_ASSERT(FAST_HOLEY_SMI_ELEMENTS == 1);
- Ldrb(scratch, FieldMemOperand(map, Map::kBitField2Offset));
- Cmp(scratch, Map::kMaximumBitField2FastHoleySmiElementValue);
- B(hi, fail);
-}
// Note: The ARM version of this clobbers elements_reg, but this version
does
=======================================
--- /branches/bleeding_edge/src/a64/macro-assembler-a64.h Tue Mar 18
14:00:21 2014 UTC
+++ /branches/bleeding_edge/src/a64/macro-assembler-a64.h Tue Mar 18
15:01:55 2014 UTC
@@ -1469,9 +1469,9 @@
// flags. The object register is preserved.
void TestMapBitfield(Register object, uint64_t mask);
- // Load the elements kind field of an object, and return it in the result
+ // Load the elements kind field from a map, and return it in the result
// register.
- void LoadElementsKind(Register result, Register object);
+ void LoadElementsKindFromMap(Register result, Register map);
// Compare the object in a register to a value from the root list.
void CompareRoot(const Register& obj, Heap::RootListIndex index);
@@ -1535,19 +1535,11 @@
// Check if a map for a JSObject indicates that the object has fast
elements.
// Jump to the specified label if it does not.
- void CheckFastElements(Register map,
- Register scratch,
- Label* fail);
+ void CheckFastElements(Register map, Register scratch, Label* fail);
// Check if a map for a JSObject indicates that the object can have both
smi
// and HeapObject elements. Jump to the specified label if it does not.
- void CheckFastObjectElements(Register map,
- Register scratch,
- Label* fail);
-
- // Check if a map for a JSObject indicates that the object has fast smi
only
- // elements. Jump to the specified label if it does not.
- void CheckFastSmiElements(Register map, Register scratch, Label* fail);
+ void CheckFastObjectElements(Register map, Register scratch, Label*
fail);
// Check to see if number can be stored as a double in
FastDoubleElements.
// If it can, store it at the index specified by key_reg in the array,
--
--
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