Revision: 21630
Author: bmeu...@chromium.org
Date: Tue Jun 3 10:59:11 2014 UTC
Log: Improve write barriers in optimized code.
Use a cheaper RecordWriteForMap() to update the
write barrier for maps. And skip the value check
in RecordWriteField() when we statically know that
the value is in new space (and therefore has "pointers
to here are interesting" flag set).
R=hpa...@chromium.org
Review URL: https://codereview.chromium.org/297763006
http://code.google.com/p/v8/source/detail?r=21630
Modified:
/branches/bleeding_edge/src/arm/lithium-codegen-arm.cc
/branches/bleeding_edge/src/arm/macro-assembler-arm.cc
/branches/bleeding_edge/src/arm/macro-assembler-arm.h
/branches/bleeding_edge/src/arm64/lithium-codegen-arm64.cc
/branches/bleeding_edge/src/arm64/macro-assembler-arm64.cc
/branches/bleeding_edge/src/arm64/macro-assembler-arm64.h
/branches/bleeding_edge/src/hydrogen-instructions.h
/branches/bleeding_edge/src/ia32/lithium-codegen-ia32.cc
/branches/bleeding_edge/src/ia32/macro-assembler-ia32.cc
/branches/bleeding_edge/src/ia32/macro-assembler-ia32.h
/branches/bleeding_edge/src/x64/lithium-codegen-x64.cc
/branches/bleeding_edge/src/x64/macro-assembler-x64.cc
/branches/bleeding_edge/src/x64/macro-assembler-x64.h
=======================================
--- /branches/bleeding_edge/src/arm/lithium-codegen-arm.cc Tue Jun 3
08:12:43 2014 UTC
+++ /branches/bleeding_edge/src/arm/lithium-codegen-arm.cc Tue Jun 3
10:59:11 2014 UTC
@@ -4084,14 +4084,11 @@
if (instr->hydrogen()->NeedsWriteBarrierForMap()) {
Register temp = ToRegister(instr->temp());
// Update the write barrier for the map field.
- __ RecordWriteField(object,
- HeapObject::kMapOffset,
- scratch,
- temp,
- GetLinkRegisterState(),
- kSaveFPRegs,
- OMIT_REMEMBERED_SET,
- OMIT_SMI_CHECK);
+ __ RecordWriteForMap(object,
+ scratch,
+ temp,
+ GetLinkRegisterState(),
+ kSaveFPRegs);
}
}
@@ -4109,7 +4106,8 @@
GetLinkRegisterState(),
kSaveFPRegs,
EMIT_REMEMBERED_SET,
- instr->hydrogen()->SmiCheckForWriteBarrier());
+ instr->hydrogen()->SmiCheckForWriteBarrier(),
+
instr->hydrogen()->PointersToHereCheckForValue());
}
} else {
__ ldr(scratch, FieldMemOperand(object, JSObject::kPropertiesOffset));
@@ -4125,7 +4123,8 @@
GetLinkRegisterState(),
kSaveFPRegs,
EMIT_REMEMBERED_SET,
- instr->hydrogen()->SmiCheckForWriteBarrier());
+ instr->hydrogen()->SmiCheckForWriteBarrier(),
+
instr->hydrogen()->PointersToHereCheckForValue());
}
}
}
@@ -4335,7 +4334,8 @@
GetLinkRegisterState(),
kSaveFPRegs,
EMIT_REMEMBERED_SET,
- check_needed);
+ check_needed,
+ instr->hydrogen()->PointersToHereCheckForValue());
}
}
@@ -4384,8 +4384,11 @@
__ mov(new_map_reg, Operand(to_map));
__ str(new_map_reg, FieldMemOperand(object_reg,
HeapObject::kMapOffset));
// Write barrier.
- __ RecordWriteField(object_reg, HeapObject::kMapOffset, new_map_reg,
- scratch, GetLinkRegisterState(), kDontSaveFPRegs);
+ __ RecordWriteForMap(object_reg,
+ new_map_reg,
+ scratch,
+ GetLinkRegisterState(),
+ kDontSaveFPRegs);
} else {
ASSERT(ToRegister(instr->context()).is(cp));
ASSERT(object_reg.is(r0));
=======================================
--- /branches/bleeding_edge/src/arm/macro-assembler-arm.cc Tue Jun 3
08:12:43 2014 UTC
+++ /branches/bleeding_edge/src/arm/macro-assembler-arm.cc Tue Jun 3
10:59:11 2014 UTC
@@ -453,7 +453,8 @@
LinkRegisterStatus lr_status,
SaveFPRegsMode save_fp,
RememberedSetAction remembered_set_action,
- SmiCheck smi_check) {
+ SmiCheck smi_check,
+ PointersToHereCheck pointers_to_here_check_for_value) {
// First, check if a write barrier is even needed. The tests below
// catch stores of Smis.
Label done;
@@ -482,7 +483,8 @@
lr_status,
save_fp,
remembered_set_action,
- OMIT_SMI_CHECK);
+ OMIT_SMI_CHECK,
+ pointers_to_here_check_for_value);
bind(&done);
@@ -493,24 +495,101 @@
mov(dst, Operand(BitCast<int32_t>(kZapValue + 8)));
}
}
+
+
+// Will clobber 4 registers: object, map, dst, ip. The
+// register 'object' contains a heap object pointer.
+void MacroAssembler::RecordWriteForMap(Register object,
+ Register map,
+ Register dst,
+ LinkRegisterStatus lr_status,
+ SaveFPRegsMode fp_mode) {
+ if (emit_debug_code()) {
+ ldr(dst, FieldMemOperand(map, HeapObject::kMapOffset));
+ cmp(dst, Operand(isolate()->factory()->meta_map()));
+ Check(eq, kWrongAddressOrValuePassedToRecordWrite);
+ }
+
+ if (!FLAG_incremental_marking) {
+ return;
+ }
+
+ // Count number of write barriers in generated code.
+ isolate()->counters()->write_barriers_static()->Increment();
+ // TODO(mstarzinger): Dynamic counter missing.
+
+ if (emit_debug_code()) {
+ ldr(ip, FieldMemOperand(object, HeapObject::kMapOffset));
+ cmp(ip, map);
+ Check(eq, kWrongAddressOrValuePassedToRecordWrite);
+ }
+
+ Label done;
+
+ // A single check of the map's pages interesting flag suffices, since it
is
+ // only set during incremental collection, and then it's also guaranteed
that
+ // the from object's page's interesting flag is also set. This
optimization
+ // relies on the fact that maps can never be in new space.
+ CheckPageFlag(map,
+ map, // Used as scratch.
+ MemoryChunk::kPointersToHereAreInterestingMask,
+ eq,
+ &done);
+
+ add(dst, object, Operand(HeapObject::kMapOffset - kHeapObjectTag));
+ if (emit_debug_code()) {
+ Label ok;
+ tst(dst, Operand((1 << kPointerSizeLog2) - 1));
+ b(eq, &ok);
+ stop("Unaligned cell in write barrier");
+ bind(&ok);
+ }
+
+ // Record the actual write.
+ if (lr_status == kLRHasNotBeenSaved) {
+ push(lr);
+ }
+ RecordWriteStub stub(isolate(), object, map, dst, OMIT_REMEMBERED_SET,
+ fp_mode);
+ CallStub(&stub);
+ if (lr_status == kLRHasNotBeenSaved) {
+ pop(lr);
+ }
+
+ bind(&done);
+
+ // Clobber clobbered registers when running with the debug-code flag
+ // turned on to provoke errors.
+ if (emit_debug_code()) {
+ mov(dst, Operand(BitCast<int32_t>(kZapValue + 12)));
+ mov(map, Operand(BitCast<int32_t>(kZapValue + 16)));
+ }
+}
// Will clobber 4 registers: object, address, scratch, ip. The
// register 'object' contains a heap object pointer. The heap object
// tag is shifted away.
-void MacroAssembler::RecordWrite(Register object,
- Register address,
- Register value,
- LinkRegisterStatus lr_status,
- SaveFPRegsMode fp_mode,
- RememberedSetAction remembered_set_action,
- SmiCheck smi_check) {
+void MacroAssembler::RecordWrite(
+ Register object,
+ Register address,
+ Register value,
+ LinkRegisterStatus lr_status,
+ SaveFPRegsMode fp_mode,
+ RememberedSetAction remembered_set_action,
+ SmiCheck smi_check,
+ PointersToHereCheck pointers_to_here_check_for_value) {
ASSERT(!object.is(value));
if (emit_debug_code()) {
ldr(ip, MemOperand(address));
cmp(ip, value);
Check(eq, kWrongAddressOrValuePassedToRecordWrite);
}
+
+ if (remembered_set_action == OMIT_REMEMBERED_SET &&
+ !FLAG_incremental_marking) {
+ return;
+ }
// Count number of write barriers in generated code.
isolate()->counters()->write_barriers_static()->Increment();
@@ -524,11 +603,13 @@
JumpIfSmi(value, &done);
}
- CheckPageFlag(value,
- value, // Used as scratch.
- MemoryChunk::kPointersToHereAreInterestingMask,
- eq,
- &done);
+ if (pointers_to_here_check_for_value !=
kPointersToHereAreAlwaysInteresting) {
+ CheckPageFlag(value,
+ value, // Used as scratch.
+ MemoryChunk::kPointersToHereAreInterestingMask,
+ eq,
+ &done);
+ }
CheckPageFlag(object,
value, // Used as scratch.
MemoryChunk::kPointersFromHereAreInterestingMask,
=======================================
--- /branches/bleeding_edge/src/arm/macro-assembler-arm.h Tue Jun 3
08:12:43 2014 UTC
+++ /branches/bleeding_edge/src/arm/macro-assembler-arm.h Tue Jun 3
10:59:11 2014 UTC
@@ -37,6 +37,10 @@
enum RememberedSetAction { EMIT_REMEMBERED_SET, OMIT_REMEMBERED_SET };
enum SmiCheck { INLINE_SMI_CHECK, OMIT_SMI_CHECK };
+enum PointersToHereCheck {
+ kPointersToHereMaybeInteresting,
+ kPointersToHereAreAlwaysInteresting
+};
enum LinkRegisterStatus { kLRHasNotBeenSaved, kLRHasBeenSaved };
@@ -244,7 +248,9 @@
LinkRegisterStatus lr_status,
SaveFPRegsMode save_fp,
RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
- SmiCheck smi_check = INLINE_SMI_CHECK);
+ SmiCheck smi_check = INLINE_SMI_CHECK,
+ PointersToHereCheck pointers_to_here_check_for_value =
+ kPointersToHereMaybeInteresting);
// As above, but the offset has the tag presubtracted. For use with
// MemOperand(reg, off).
@@ -256,7 +262,9 @@
LinkRegisterStatus lr_status,
SaveFPRegsMode save_fp,
RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
- SmiCheck smi_check = INLINE_SMI_CHECK) {
+ SmiCheck smi_check = INLINE_SMI_CHECK,
+ PointersToHereCheck pointers_to_here_check_for_value =
+ kPointersToHereMaybeInteresting) {
RecordWriteField(context,
offset + kHeapObjectTag,
value,
@@ -264,8 +272,16 @@
lr_status,
save_fp,
remembered_set_action,
- smi_check);
+ smi_check,
+ pointers_to_here_check_for_value);
}
+
+ void RecordWriteForMap(
+ Register object,
+ Register map,
+ Register dst,
+ LinkRegisterStatus lr_status,
+ SaveFPRegsMode save_fp);
// For a given |object| notify the garbage collector that the slot |
address|
// has been written. |value| is the object being stored. The value and
@@ -277,7 +293,9 @@
LinkRegisterStatus lr_status,
SaveFPRegsMode save_fp,
RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
- SmiCheck smi_check = INLINE_SMI_CHECK);
+ SmiCheck smi_check = INLINE_SMI_CHECK,
+ PointersToHereCheck pointers_to_here_check_for_value =
+ kPointersToHereMaybeInteresting);
// Push a handle.
void Push(Handle<Object> handle);
=======================================
--- /branches/bleeding_edge/src/arm64/lithium-codegen-arm64.cc Tue Jun 3
08:12:43 2014 UTC
+++ /branches/bleeding_edge/src/arm64/lithium-codegen-arm64.cc Tue Jun 3
10:59:11 2014 UTC
@@ -5320,7 +5320,8 @@
// Compute address of modified element and store it into key register.
__ Add(element_addr, mem_op.base(), mem_op.OffsetAsOperand());
__ RecordWrite(elements, element_addr, value, GetLinkRegisterState(),
- kSaveFPRegs, EMIT_REMEMBERED_SET, check_needed);
+ kSaveFPRegs, EMIT_REMEMBERED_SET, check_needed,
+ instr->hydrogen()->PointersToHereCheckForValue());
}
}
@@ -5379,14 +5380,11 @@
__ Str(new_map_value, FieldMemOperand(object, HeapObject::kMapOffset));
if (instr->hydrogen()->NeedsWriteBarrierForMap()) {
// Update the write barrier for the map field.
- __ RecordWriteField(object,
- HeapObject::kMapOffset,
- new_map_value,
- ToRegister(instr->temp1()),
- GetLinkRegisterState(),
- kSaveFPRegs,
- OMIT_REMEMBERED_SET,
- OMIT_SMI_CHECK);
+ __ RecordWriteForMap(object,
+ new_map_value,
+ ToRegister(instr->temp1()),
+ GetLinkRegisterState(),
+ kSaveFPRegs);
}
}
@@ -5428,7 +5426,8 @@
GetLinkRegisterState(),
kSaveFPRegs,
EMIT_REMEMBERED_SET,
- instr->hydrogen()->SmiCheckForWriteBarrier());
+ instr->hydrogen()->SmiCheckForWriteBarrier(),
+ instr->hydrogen()->PointersToHereCheckForValue());
}
}
@@ -5760,8 +5759,8 @@
__ Mov(new_map, Operand(to_map));
__ Str(new_map, FieldMemOperand(object, HeapObject::kMapOffset));
// Write barrier.
- __ RecordWriteField(object, HeapObject::kMapOffset, new_map, temp1,
- GetLinkRegisterState(), kDontSaveFPRegs);
+ __ RecordWriteForMap(object, new_map, temp1, GetLinkRegisterState(),
+ kDontSaveFPRegs);
} else {
{
UseScratchRegisterScope temps(masm());
=======================================
--- /branches/bleeding_edge/src/arm64/macro-assembler-arm64.cc Tue Jun 3
08:12:43 2014 UTC
+++ /branches/bleeding_edge/src/arm64/macro-assembler-arm64.cc Tue Jun 3
10:59:11 2014 UTC
@@ -4272,7 +4272,8 @@
LinkRegisterStatus lr_status,
SaveFPRegsMode save_fp,
RememberedSetAction remembered_set_action,
- SmiCheck smi_check) {
+ SmiCheck smi_check,
+ PointersToHereCheck pointers_to_here_check_for_value) {
// First, check if a write barrier is even needed. The tests below
// catch stores of Smis.
Label done;
@@ -4301,7 +4302,8 @@
lr_status,
save_fp,
remembered_set_action,
- OMIT_SMI_CHECK);
+ OMIT_SMI_CHECK,
+ pointers_to_here_check_for_value);
Bind(&done);
@@ -4312,6 +4314,77 @@
Mov(scratch, Operand(BitCast<int64_t>(kZapValue + 8)));
}
}
+
+
+// Will clobber: object, map, dst.
+// If lr_status is kLRHasBeenSaved, lr will also be clobbered.
+void MacroAssembler::RecordWriteForMap(Register object,
+ Register map,
+ Register dst,
+ LinkRegisterStatus lr_status,
+ SaveFPRegsMode fp_mode) {
+ ASM_LOCATION("MacroAssembler::RecordWrite");
+ ASSERT(!AreAliased(object, map));
+
+ if (emit_debug_code()) {
+ UseScratchRegisterScope temps(this);
+ Register temp = temps.AcquireX();
+
+ CompareMap(map, temp, isolate()->factory()->meta_map());
+ Check(eq, kWrongAddressOrValuePassedToRecordWrite);
+ }
+
+ if (!FLAG_incremental_marking) {
+ return;
+ }
+
+ if (emit_debug_code()) {
+ UseScratchRegisterScope temps(this);
+ Register temp = temps.AcquireX();
+
+ Ldr(temp, FieldMemOperand(object, HeapObject::kMapOffset));
+ Cmp(temp, map);
+ Check(eq, kWrongAddressOrValuePassedToRecordWrite);
+ }
+
+ // Count number of write barriers in generated code.
+ isolate()->counters()->write_barriers_static()->Increment();
+ // TODO(mstarzinger): Dynamic counter missing.
+
+ // First, check if a write barrier is even needed. The tests below
+ // catch stores of smis and stores into the young generation.
+ Label done;
+
+ // A single check of the map's pages interesting flag suffices, since it
is
+ // only set during incremental collection, and then it's also guaranteed
that
+ // the from object's page's interesting flag is also set. This
optimization
+ // relies on the fact that maps can never be in new space.
+ CheckPageFlagClear(map,
+ map, // Used as scratch.
+ MemoryChunk::kPointersToHereAreInterestingMask,
+ &done);
+
+ // Record the actual write.
+ if (lr_status == kLRHasNotBeenSaved) {
+ Push(lr);
+ }
+ Add(dst, object, HeapObject::kMapOffset - kHeapObjectTag);
+ RecordWriteStub stub(isolate(), object, map, dst, OMIT_REMEMBERED_SET,
+ fp_mode);
+ CallStub(&stub);
+ if (lr_status == kLRHasNotBeenSaved) {
+ Pop(lr);
+ }
+
+ Bind(&done);
+
+ // Clobber clobbered registers when running with the debug-code flag
+ // turned on to provoke errors.
+ if (emit_debug_code()) {
+ Mov(dst, Operand(BitCast<int64_t>(kZapValue + 12)));
+ Mov(map, Operand(BitCast<int64_t>(kZapValue + 16)));
+ }
+}
// Will clobber: object, address, value.
@@ -4319,13 +4392,15 @@
//
// The register 'object' contains a heap object pointer. The heap object
tag is
// shifted away.
-void MacroAssembler::RecordWrite(Register object,
- Register address,
- Register value,
- LinkRegisterStatus lr_status,
- SaveFPRegsMode fp_mode,
- RememberedSetAction remembered_set_action,
- SmiCheck smi_check) {
+void MacroAssembler::RecordWrite(
+ Register object,
+ Register address,
+ Register value,
+ LinkRegisterStatus lr_status,
+ SaveFPRegsMode fp_mode,
+ RememberedSetAction remembered_set_action,
+ SmiCheck smi_check,
+ PointersToHereCheck pointers_to_here_check_for_value) {
ASM_LOCATION("MacroAssembler::RecordWrite");
ASSERT(!AreAliased(object, value));
@@ -4351,10 +4426,12 @@
JumpIfSmi(value, &done);
}
- CheckPageFlagClear(value,
- value, // Used as scratch.
- MemoryChunk::kPointersToHereAreInterestingMask,
- &done);
+ if (pointers_to_here_check_for_value !=
kPointersToHereAreAlwaysInteresting) {
+ CheckPageFlagClear(value,
+ value, // Used as scratch.
+ MemoryChunk::kPointersToHereAreInterestingMask,
+ &done);
+ }
CheckPageFlagClear(object,
value, // Used as scratch.
MemoryChunk::kPointersFromHereAreInterestingMask,
=======================================
--- /branches/bleeding_edge/src/arm64/macro-assembler-arm64.h Tue Jun 3
08:12:43 2014 UTC
+++ /branches/bleeding_edge/src/arm64/macro-assembler-arm64.h Tue Jun 3
10:59:11 2014 UTC
@@ -89,6 +89,10 @@
enum RememberedSetAction { EMIT_REMEMBERED_SET, OMIT_REMEMBERED_SET };
enum SmiCheck { INLINE_SMI_CHECK, OMIT_SMI_CHECK };
+enum PointersToHereCheck {
+ kPointersToHereMaybeInteresting,
+ kPointersToHereAreAlwaysInteresting
+};
enum LinkRegisterStatus { kLRHasNotBeenSaved, kLRHasBeenSaved };
enum TargetAddressStorageMode {
CAN_INLINE_TARGET_ADDRESS,
@@ -1787,7 +1791,9 @@
LinkRegisterStatus lr_status,
SaveFPRegsMode save_fp,
RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
- SmiCheck smi_check = INLINE_SMI_CHECK);
+ SmiCheck smi_check = INLINE_SMI_CHECK,
+ PointersToHereCheck pointers_to_here_check_for_value =
+ kPointersToHereMaybeInteresting);
// As above, but the offset has the tag presubtracted. For use with
// MemOperand(reg, off).
@@ -1799,7 +1805,9 @@
LinkRegisterStatus lr_status,
SaveFPRegsMode save_fp,
RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
- SmiCheck smi_check = INLINE_SMI_CHECK) {
+ SmiCheck smi_check = INLINE_SMI_CHECK,
+ PointersToHereCheck pointers_to_here_check_for_value =
+ kPointersToHereMaybeInteresting) {
RecordWriteField(context,
offset + kHeapObjectTag,
value,
@@ -1807,8 +1815,16 @@
lr_status,
save_fp,
remembered_set_action,
- smi_check);
+ smi_check,
+ pointers_to_here_check_for_value);
}
+
+ void RecordWriteForMap(
+ Register object,
+ Register map,
+ Register dst,
+ LinkRegisterStatus lr_status,
+ SaveFPRegsMode save_fp);
// For a given |object| notify the garbage collector that the slot |
address|
// has been written. |value| is the object being stored. The value and
@@ -1820,7 +1836,9 @@
LinkRegisterStatus lr_status,
SaveFPRegsMode save_fp,
RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
- SmiCheck smi_check = INLINE_SMI_CHECK);
+ SmiCheck smi_check = INLINE_SMI_CHECK,
+ PointersToHereCheck pointers_to_here_check_for_value =
+ kPointersToHereMaybeInteresting);
// Checks the color of an object. If the object is already grey or black
// then we just fall through, since it is already live. If it is white
and
=======================================
--- /branches/bleeding_edge/src/hydrogen-instructions.h Tue Jun 3 10:40:36
2014 UTC
+++ /branches/bleeding_edge/src/hydrogen-instructions.h Tue Jun 3 10:59:11
2014 UTC
@@ -5713,6 +5713,20 @@
}
return true;
}
+
+
+inline PointersToHereCheck PointersToHereCheckForObject(HValue* object,
+ HValue* dominator)
{
+ while (object->IsInnerAllocatedObject()) {
+ object = HInnerAllocatedObject::cast(object)->base_object();
+ }
+ if (object == dominator &&
+ object->IsAllocate() &&
+ HAllocate::cast(object)->IsNewSpaceAllocation()) {
+ return kPointersToHereAreAlwaysInteresting;
+ }
+ return kPointersToHereMaybeInteresting;
+}
class HStoreGlobalCell V8_FINAL : public HUnaryOperation {
@@ -6731,6 +6745,10 @@
if (value()->type().IsHeapObject()) return OMIT_SMI_CHECK;
return INLINE_SMI_CHECK;
}
+
+ PointersToHereCheck PointersToHereCheckForValue() const {
+ return PointersToHereCheckForObject(value(), dominator());
+ }
Representation field_representation() const {
return access_.representation();
@@ -6890,9 +6908,9 @@
return Representation::None();
}
- HValue* elements() { return OperandAt(0); }
- HValue* key() { return OperandAt(1); }
- HValue* value() { return OperandAt(2); }
+ HValue* elements() const { return OperandAt(0); }
+ HValue* key() const { return OperandAt(1); }
+ HValue* value() const { return OperandAt(2); }
bool value_is_smi() const {
return IsFastSmiElementsKind(elements_kind_);
}
@@ -6935,6 +6953,10 @@
ReceiverObjectNeedsWriteBarrier(elements(), value(),
dominator());
}
}
+
+ PointersToHereCheck PointersToHereCheckForValue() const {
+ return PointersToHereCheckForObject(value(), dominator());
+ }
bool NeedsCanonicalization();
=======================================
--- /branches/bleeding_edge/src/ia32/lithium-codegen-ia32.cc Tue Jun 3
08:12:43 2014 UTC
+++ /branches/bleeding_edge/src/ia32/lithium-codegen-ia32.cc Tue Jun 3
10:59:11 2014 UTC
@@ -3995,21 +3995,12 @@
if (instr->hydrogen()->has_transition()) {
Handle<Map> transition = instr->hydrogen()->transition_map();
AddDeprecationDependency(transition);
- if (!instr->hydrogen()->NeedsWriteBarrierForMap()) {
- __ mov(FieldOperand(object, HeapObject::kMapOffset), transition);
- } else {
+ __ mov(FieldOperand(object, HeapObject::kMapOffset), transition);
+ if (instr->hydrogen()->NeedsWriteBarrierForMap()) {
Register temp = ToRegister(instr->temp());
Register temp_map = ToRegister(instr->temp_map());
- __ mov(temp_map, transition);
- __ mov(FieldOperand(object, HeapObject::kMapOffset), temp_map);
// Update the write barrier for the map field.
- __ RecordWriteField(object,
- HeapObject::kMapOffset,
- temp_map,
- temp,
- kSaveFPRegs,
- OMIT_REMEMBERED_SET,
- OMIT_SMI_CHECK);
+ __ RecordWriteForMap(object, transition, temp_map, temp,
kSaveFPRegs);
}
}
@@ -4050,7 +4041,8 @@
temp,
kSaveFPRegs,
EMIT_REMEMBERED_SET,
- instr->hydrogen()->SmiCheckForWriteBarrier());
+ instr->hydrogen()->SmiCheckForWriteBarrier(),
+ instr->hydrogen()->PointersToHereCheckForValue());
}
}
@@ -4219,7 +4211,8 @@
value,
kSaveFPRegs,
EMIT_REMEMBERED_SET,
- check_needed);
+ check_needed,
+ instr->hydrogen()->PointersToHereCheckForValue());
}
}
=======================================
--- /branches/bleeding_edge/src/ia32/macro-assembler-ia32.cc Tue Jun 3
08:12:43 2014 UTC
+++ /branches/bleeding_edge/src/ia32/macro-assembler-ia32.cc Tue Jun 3
10:59:11 2014 UTC
@@ -392,12 +392,14 @@
}
-void MacroAssembler::RecordWriteArray(Register object,
- Register value,
- Register index,
- SaveFPRegsMode save_fp,
- RememberedSetAction
remembered_set_action,
- SmiCheck smi_check) {
+void MacroAssembler::RecordWriteArray(
+ Register object,
+ Register value,
+ Register index,
+ SaveFPRegsMode save_fp,
+ RememberedSetAction remembered_set_action,
+ SmiCheck smi_check,
+ PointersToHereCheck pointers_to_here_check_for_value) {
// First, check if a write barrier is even needed. The tests below
// catch stores of Smis.
Label done;
@@ -416,8 +418,8 @@
lea(dst, Operand(object, index, times_half_pointer_size,
FixedArray::kHeaderSize - kHeapObjectTag));
- RecordWrite(
- object, dst, value, save_fp, remembered_set_action, OMIT_SMI_CHECK);
+ RecordWrite(object, dst, value, save_fp, remembered_set_action,
+ OMIT_SMI_CHECK, pointers_to_here_check_for_value);
bind(&done);
@@ -437,7 +439,8 @@
Register dst,
SaveFPRegsMode save_fp,
RememberedSetAction remembered_set_action,
- SmiCheck smi_check) {
+ SmiCheck smi_check,
+ PointersToHereCheck pointers_to_here_check_for_value) {
// First, check if a write barrier is even needed. The tests below
// catch stores of Smis.
Label done;
@@ -460,8 +463,8 @@
bind(&ok);
}
- RecordWrite(
- object, dst, value, save_fp, remembered_set_action, OMIT_SMI_CHECK);
+ RecordWrite(object, dst, value, save_fp, remembered_set_action,
+ OMIT_SMI_CHECK, pointers_to_here_check_for_value);
bind(&done);
@@ -501,6 +504,9 @@
if (!FLAG_incremental_marking) {
return;
}
+
+ // Compute the address.
+ lea(address, FieldOperand(object, HeapObject::kMapOffset));
// Count number of write barriers in generated code.
isolate()->counters()->write_barriers_static()->Increment();
@@ -517,12 +523,6 @@
&done,
Label::kNear);
- // Delay the initialization of |address| and |value| for the stub until
it's
- // known that the will be needed. Up until this point their values are
not
- // needed since they are embedded in the operands of instructions that
need
- // them.
- lea(address, FieldOperand(object, HeapObject::kMapOffset));
- mov(value, Immediate(map));
RecordWriteStub stub(isolate(), object, value, address,
OMIT_REMEMBERED_SET,
save_fp);
CallStub(&stub);
@@ -539,12 +539,14 @@
}
-void MacroAssembler::RecordWrite(Register object,
- Register address,
- Register value,
- SaveFPRegsMode fp_mode,
- RememberedSetAction remembered_set_action,
- SmiCheck smi_check) {
+void MacroAssembler::RecordWrite(
+ Register object,
+ Register address,
+ Register value,
+ SaveFPRegsMode fp_mode,
+ RememberedSetAction remembered_set_action,
+ SmiCheck smi_check,
+ PointersToHereCheck pointers_to_here_check_for_value) {
ASSERT(!object.is(value));
ASSERT(!object.is(address));
ASSERT(!value.is(address));
@@ -576,12 +578,14 @@
JumpIfSmi(value, &done, Label::kNear);
}
- CheckPageFlag(value,
- value, // Used as scratch.
- MemoryChunk::kPointersToHereAreInterestingMask,
- zero,
- &done,
- Label::kNear);
+ if (pointers_to_here_check_for_value !=
kPointersToHereAreAlwaysInteresting) {
+ CheckPageFlag(value,
+ value, // Used as scratch.
+ MemoryChunk::kPointersToHereAreInterestingMask,
+ zero,
+ &done,
+ Label::kNear);
+ }
CheckPageFlag(object,
value, // Used as scratch.
MemoryChunk::kPointersFromHereAreInterestingMask,
=======================================
--- /branches/bleeding_edge/src/ia32/macro-assembler-ia32.h Tue Jun 3
08:12:43 2014 UTC
+++ /branches/bleeding_edge/src/ia32/macro-assembler-ia32.h Tue Jun 3
10:59:11 2014 UTC
@@ -18,6 +18,10 @@
enum RememberedSetAction { EMIT_REMEMBERED_SET, OMIT_REMEMBERED_SET };
enum SmiCheck { INLINE_SMI_CHECK, OMIT_SMI_CHECK };
+enum PointersToHereCheck {
+ kPointersToHereMaybeInteresting,
+ kPointersToHereAreAlwaysInteresting
+};
enum RegisterValueType {
@@ -140,7 +144,9 @@
Register scratch,
SaveFPRegsMode save_fp,
RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
- SmiCheck smi_check = INLINE_SMI_CHECK);
+ SmiCheck smi_check = INLINE_SMI_CHECK,
+ PointersToHereCheck pointers_to_here_check_for_value =
+ kPointersToHereMaybeInteresting);
// As above, but the offset has the tag presubtracted. For use with
// Operand(reg, off).
@@ -151,14 +157,17 @@
Register scratch,
SaveFPRegsMode save_fp,
RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
- SmiCheck smi_check = INLINE_SMI_CHECK) {
+ SmiCheck smi_check = INLINE_SMI_CHECK,
+ PointersToHereCheck pointers_to_here_check_for_value =
+ kPointersToHereMaybeInteresting) {
RecordWriteField(context,
offset + kHeapObjectTag,
value,
scratch,
save_fp,
remembered_set_action,
- smi_check);
+ smi_check,
+ pointers_to_here_check_for_value);
}
// Notify the garbage collector that we wrote a pointer into a fixed
array.
@@ -173,7 +182,9 @@
Register index,
SaveFPRegsMode save_fp,
RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
- SmiCheck smi_check = INLINE_SMI_CHECK);
+ SmiCheck smi_check = INLINE_SMI_CHECK,
+ PointersToHereCheck pointers_to_here_check_for_value =
+ kPointersToHereMaybeInteresting);
// For page containing |object| mark region covering |address|
// dirty. |object| is the object being stored into, |value| is the
@@ -186,7 +197,9 @@
Register value,
SaveFPRegsMode save_fp,
RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
- SmiCheck smi_check = INLINE_SMI_CHECK);
+ SmiCheck smi_check = INLINE_SMI_CHECK,
+ PointersToHereCheck pointers_to_here_check_for_value =
+ kPointersToHereMaybeInteresting);
// For page containing |object| mark the region covering the object's map
// dirty. |object| is the object being stored into, |map| is the Map
object
=======================================
--- /branches/bleeding_edge/src/x64/lithium-codegen-x64.cc Tue Jun 3
08:12:43 2014 UTC
+++ /branches/bleeding_edge/src/x64/lithium-codegen-x64.cc Tue Jun 3
10:59:11 2014 UTC
@@ -4024,13 +4024,10 @@
__ Move(kScratchRegister, transition);
__ movp(FieldOperand(object, HeapObject::kMapOffset),
kScratchRegister);
// Update the write barrier for the map field.
- __ RecordWriteField(object,
- HeapObject::kMapOffset,
- kScratchRegister,
- temp,
- kSaveFPRegs,
- OMIT_REMEMBERED_SET,
- OMIT_SMI_CHECK);
+ __ RecordWriteForMap(object,
+ kScratchRegister,
+ temp,
+ kSaveFPRegs);
}
}
@@ -4090,7 +4087,8 @@
temp,
kSaveFPRegs,
EMIT_REMEMBERED_SET,
- hinstr->SmiCheckForWriteBarrier());
+ hinstr->SmiCheckForWriteBarrier(),
+ hinstr->PointersToHereCheckForValue());
}
}
@@ -4315,7 +4313,8 @@
value,
kSaveFPRegs,
EMIT_REMEMBERED_SET,
- check_needed);
+ check_needed,
+ hinstr->PointersToHereCheckForValue());
}
}
@@ -4360,9 +4359,8 @@
__ Move(new_map_reg, to_map, RelocInfo::EMBEDDED_OBJECT);
__ movp(FieldOperand(object_reg, HeapObject::kMapOffset), new_map_reg);
// Write barrier.
- ASSERT_NE(instr->temp(), NULL);
- __ RecordWriteField(object_reg, HeapObject::kMapOffset, new_map_reg,
- ToRegister(instr->temp()), kDontSaveFPRegs);
+ __ RecordWriteForMap(object_reg, new_map_reg,
ToRegister(instr->temp()),
+ kDontSaveFPRegs);
} else {
ASSERT(object_reg.is(rax));
ASSERT(ToRegister(instr->context()).is(rsi));
=======================================
--- /branches/bleeding_edge/src/x64/macro-assembler-x64.cc Tue Jun 3
08:12:43 2014 UTC
+++ /branches/bleeding_edge/src/x64/macro-assembler-x64.cc Tue Jun 3
10:59:11 2014 UTC
@@ -292,7 +292,8 @@
Register dst,
SaveFPRegsMode save_fp,
RememberedSetAction remembered_set_action,
- SmiCheck smi_check) {
+ SmiCheck smi_check,
+ PointersToHereCheck pointers_to_here_check_for_value) {
// First, check if a write barrier is even needed. The tests below
// catch stores of Smis.
Label done;
@@ -315,8 +316,8 @@
bind(&ok);
}
- RecordWrite(
- object, dst, value, save_fp, remembered_set_action, OMIT_SMI_CHECK);
+ RecordWrite(object, dst, value, save_fp, remembered_set_action,
+ OMIT_SMI_CHECK, pointers_to_here_check_for_value);
bind(&done);
@@ -329,12 +330,14 @@
}
-void MacroAssembler::RecordWriteArray(Register object,
- Register value,
- Register index,
- SaveFPRegsMode save_fp,
- RememberedSetAction
remembered_set_action,
- SmiCheck smi_check) {
+void MacroAssembler::RecordWriteArray(
+ Register object,
+ Register value,
+ Register index,
+ SaveFPRegsMode save_fp,
+ RememberedSetAction remembered_set_action,
+ SmiCheck smi_check,
+ PointersToHereCheck pointers_to_here_check_for_value) {
// First, check if a write barrier is even needed. The tests below
// catch stores of Smis.
Label done;
@@ -349,8 +352,8 @@
leap(dst, Operand(object, index, times_pointer_size,
FixedArray::kHeaderSize - kHeapObjectTag));
- RecordWrite(
- object, dst, value, save_fp, remembered_set_action, OMIT_SMI_CHECK);
+ RecordWrite(object, dst, value, save_fp, remembered_set_action,
+ OMIT_SMI_CHECK, pointers_to_here_check_for_value);
bind(&done);
@@ -363,12 +366,85 @@
}
-void MacroAssembler::RecordWrite(Register object,
- Register address,
- Register value,
- SaveFPRegsMode fp_mode,
- RememberedSetAction remembered_set_action,
- SmiCheck smi_check) {
+void MacroAssembler::RecordWriteForMap(Register object,
+ Register map,
+ Register dst,
+ SaveFPRegsMode fp_mode) {
+ ASSERT(!object.is(kScratchRegister));
+ ASSERT(!object.is(map));
+ ASSERT(!object.is(dst));
+ ASSERT(!map.is(dst));
+ AssertNotSmi(object);
+
+ if (emit_debug_code()) {
+ Label ok;
+ if (map.is(kScratchRegister)) pushq(map);
+ CompareMap(map, isolate()->factory()->meta_map());
+ if (map.is(kScratchRegister)) popq(map);
+ j(equal, &ok, Label::kNear);
+ int3();
+ bind(&ok);
+ }
+
+ if (!FLAG_incremental_marking) {
+ return;
+ }
+
+ if (emit_debug_code()) {
+ Label ok;
+ if (map.is(kScratchRegister)) pushq(map);
+ cmpp(map, FieldOperand(object, HeapObject::kMapOffset));
+ if (map.is(kScratchRegister)) popq(map);
+ j(equal, &ok, Label::kNear);
+ int3();
+ bind(&ok);
+ }
+
+ // Compute the address.
+ leap(dst, FieldOperand(object, HeapObject::kMapOffset));
+
+ // Count number of write barriers in generated code.
+ isolate()->counters()->write_barriers_static()->Increment();
+ IncrementCounter(isolate()->counters()->write_barriers_dynamic(), 1);
+
+ // First, check if a write barrier is even needed. The tests below
+ // catch stores of smis and stores into the young generation.
+ Label done;
+
+ // A single check of the map's pages interesting flag suffices, since it
is
+ // only set during incremental collection, and then it's also guaranteed
that
+ // the from object's page's interesting flag is also set. This
optimization
+ // relies on the fact that maps can never be in new space.
+ CheckPageFlag(map,
+ map, // Used as scratch.
+ MemoryChunk::kPointersToHereAreInterestingMask,
+ zero,
+ &done,
+ Label::kNear);
+
+ RecordWriteStub stub(isolate(), object, map, dst, OMIT_REMEMBERED_SET,
+ fp_mode);
+ CallStub(&stub);
+
+ bind(&done);
+
+ // Clobber clobbered registers when running with the debug-code flag
+ // turned on to provoke errors.
+ if (emit_debug_code()) {
+ Move(dst, kZapValue, Assembler::RelocInfoNone());
+ Move(map, kZapValue, Assembler::RelocInfoNone());
+ }
+}
+
+
+void MacroAssembler::RecordWrite(
+ Register object,
+ Register address,
+ Register value,
+ SaveFPRegsMode fp_mode,
+ RememberedSetAction remembered_set_action,
+ SmiCheck smi_check,
+ PointersToHereCheck pointers_to_here_check_for_value) {
ASSERT(!object.is(value));
ASSERT(!object.is(address));
ASSERT(!value.is(address));
@@ -400,12 +476,14 @@
JumpIfSmi(value, &done);
}
- CheckPageFlag(value,
- value, // Used as scratch.
- MemoryChunk::kPointersToHereAreInterestingMask,
- zero,
- &done,
- Label::kNear);
+ if (pointers_to_here_check_for_value !=
kPointersToHereAreAlwaysInteresting) {
+ CheckPageFlag(value,
+ value, // Used as scratch.
+ MemoryChunk::kPointersToHereAreInterestingMask,
+ zero,
+ &done,
+ Label::kNear);
+ }
CheckPageFlag(object,
value, // Used as scratch.
=======================================
--- /branches/bleeding_edge/src/x64/macro-assembler-x64.h Tue Jun 3
08:12:43 2014 UTC
+++ /branches/bleeding_edge/src/x64/macro-assembler-x64.h Tue Jun 3
10:59:11 2014 UTC
@@ -29,6 +29,10 @@
enum RememberedSetAction { EMIT_REMEMBERED_SET, OMIT_REMEMBERED_SET };
enum SmiCheck { INLINE_SMI_CHECK, OMIT_SMI_CHECK };
+enum PointersToHereCheck {
+ kPointersToHereMaybeInteresting,
+ kPointersToHereAreAlwaysInteresting
+};
enum SmiOperationConstraint {
PRESERVE_SOURCE_REGISTER,
@@ -220,7 +224,9 @@
Register scratch,
SaveFPRegsMode save_fp,
RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
- SmiCheck smi_check = INLINE_SMI_CHECK);
+ SmiCheck smi_check = INLINE_SMI_CHECK,
+ PointersToHereCheck pointers_to_here_check_for_value =
+ kPointersToHereMaybeInteresting);
// As above, but the offset has the tag presubtracted. For use with
// Operand(reg, off).
@@ -231,14 +237,17 @@
Register scratch,
SaveFPRegsMode save_fp,
RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
- SmiCheck smi_check = INLINE_SMI_CHECK) {
+ SmiCheck smi_check = INLINE_SMI_CHECK,
+ PointersToHereCheck pointers_to_here_check_for_value =
+ kPointersToHereMaybeInteresting) {
RecordWriteField(context,
offset + kHeapObjectTag,
value,
scratch,
save_fp,
remembered_set_action,
- smi_check);
+ smi_check,
+ pointers_to_here_check_for_value);
}
// Notify the garbage collector that we wrote a pointer into a fixed
array.
@@ -253,7 +262,15 @@
Register index,
SaveFPRegsMode save_fp,
RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
- SmiCheck smi_check = INLINE_SMI_CHECK);
+ SmiCheck smi_check = INLINE_SMI_CHECK,
+ PointersToHereCheck pointers_to_here_check_for_value =
+ kPointersToHereMaybeInteresting);
+
+ void RecordWriteForMap(
+ Register object,
+ Register map,
+ Register dst,
+ SaveFPRegsMode save_fp);
// For page containing |object| mark region covering |address|
// dirty. |object| is the object being stored into, |value| is the
@@ -266,7 +283,9 @@
Register value,
SaveFPRegsMode save_fp,
RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
- SmiCheck smi_check = INLINE_SMI_CHECK);
+ SmiCheck smi_check = INLINE_SMI_CHECK,
+ PointersToHereCheck pointers_to_here_check_for_value =
+ kPointersToHereMaybeInteresting);
//
---------------------------------------------------------------------------
// Debugger Support
--
--
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