Revision: 21663
Author: [email protected]
Date: Wed Jun 4 07:18:06 2014 UTC
Log: Version 3.27.19.1 (merged r21657)
MIPS: Improve write barriers in optimized code.
[email protected]
BUG=
Review URL: https://codereview.chromium.org/314873003
http://code.google.com/p/v8/source/detail?r=21663
Modified:
/trunk/src/mips/lithium-codegen-mips.cc
/trunk/src/mips/macro-assembler-mips.cc
/trunk/src/mips/macro-assembler-mips.h
/trunk/src/version.cc
=======================================
--- /trunk/src/mips/lithium-codegen-mips.cc Wed Jun 4 00:06:13 2014 UTC
+++ /trunk/src/mips/lithium-codegen-mips.cc Wed Jun 4 07:18:06 2014 UTC
@@ -4077,14 +4077,11 @@
if (instr->hydrogen()->NeedsWriteBarrierForMap()) {
Register temp = ToRegister(instr->temp());
// Update the write barrier for the map field.
- __ RecordWriteField(object,
- HeapObject::kMapOffset,
- scratch,
- temp,
- GetRAState(),
- kSaveFPRegs,
- OMIT_REMEMBERED_SET,
- OMIT_SMI_CHECK);
+ __ RecordWriteForMap(object,
+ scratch,
+ temp,
+ GetRAState(),
+ kSaveFPRegs);
}
}
@@ -4102,7 +4099,8 @@
GetRAState(),
kSaveFPRegs,
EMIT_REMEMBERED_SET,
- instr->hydrogen()->SmiCheckForWriteBarrier());
+ instr->hydrogen()->SmiCheckForWriteBarrier(),
+
instr->hydrogen()->PointersToHereCheckForValue());
}
} else {
__ lw(scratch, FieldMemOperand(object, JSObject::kPropertiesOffset));
@@ -4118,7 +4116,8 @@
GetRAState(),
kSaveFPRegs,
EMIT_REMEMBERED_SET,
- instr->hydrogen()->SmiCheckForWriteBarrier());
+ instr->hydrogen()->SmiCheckForWriteBarrier(),
+
instr->hydrogen()->PointersToHereCheckForValue());
}
}
}
@@ -4338,7 +4337,8 @@
GetRAState(),
kSaveFPRegs,
EMIT_REMEMBERED_SET,
- check_needed);
+ check_needed,
+ instr->hydrogen()->PointersToHereCheckForValue());
}
}
@@ -4386,8 +4386,11 @@
__ li(new_map_reg, Operand(to_map));
__ sw(new_map_reg, FieldMemOperand(object_reg,
HeapObject::kMapOffset));
// Write barrier.
- __ RecordWriteField(object_reg, HeapObject::kMapOffset, new_map_reg,
- scratch, GetRAState(), kDontSaveFPRegs);
+ __ RecordWriteForMap(object_reg,
+ new_map_reg,
+ scratch,
+ GetRAState(),
+ kDontSaveFPRegs);
} else {
ASSERT(object_reg.is(a0));
ASSERT(ToRegister(instr->context()).is(cp));
=======================================
--- /trunk/src/mips/macro-assembler-mips.cc Wed Jun 4 00:06:13 2014 UTC
+++ /trunk/src/mips/macro-assembler-mips.cc Wed Jun 4 07:18:06 2014 UTC
@@ -194,7 +194,8 @@
RAStatus ra_status,
SaveFPRegsMode save_fp,
RememberedSetAction remembered_set_action,
- SmiCheck smi_check) {
+ SmiCheck smi_check,
+ PointersToHereCheck pointers_to_here_check_for_value) {
ASSERT(!AreAliased(value, dst, t8, object));
// First, check if a write barrier is even needed. The tests below
// catch stores of Smis.
@@ -224,7 +225,8 @@
ra_status,
save_fp,
remembered_set_action,
- OMIT_SMI_CHECK);
+ OMIT_SMI_CHECK,
+ pointers_to_here_check_for_value);
bind(&done);
@@ -235,18 +237,95 @@
li(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,
+ RAStatus ra_status,
+ SaveFPRegsMode fp_mode) {
+ if (emit_debug_code()) {
+ ASSERT(!dst.is(at));
+ lw(dst, FieldMemOperand(map, HeapObject::kMapOffset));
+ Check(eq,
+ kWrongAddressOrValuePassedToRecordWrite,
+ dst,
+ Operand(isolate()->factory()->meta_map()));
+ }
+
+ 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()) {
+ lw(at, FieldMemOperand(object, HeapObject::kMapOffset));
+ Check(eq,
+ kWrongAddressOrValuePassedToRecordWrite,
+ map,
+ Operand(at));
+ }
+
+ 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);
+
+ Addu(dst, object, Operand(HeapObject::kMapOffset - kHeapObjectTag));
+ if (emit_debug_code()) {
+ Label ok;
+ And(at, dst, Operand((1 << kPointerSizeLog2) - 1));
+ Branch(&ok, eq, at, Operand(zero_reg));
+ stop("Unaligned cell in write barrier");
+ bind(&ok);
+ }
+
+ // Record the actual write.
+ if (ra_status == kRAHasNotBeenSaved) {
+ push(ra);
+ }
+ RecordWriteStub stub(isolate(), object, map, dst, OMIT_REMEMBERED_SET,
+ fp_mode);
+ CallStub(&stub);
+ if (ra_status == kRAHasNotBeenSaved) {
+ pop(ra);
+ }
+
+ bind(&done);
+
+ // Clobber clobbered registers when running with the debug-code flag
+ // turned on to provoke errors.
+ if (emit_debug_code()) {
+ li(dst, Operand(BitCast<int32_t>(kZapValue + 12)));
+ li(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,
- RAStatus ra_status,
- SaveFPRegsMode fp_mode,
- RememberedSetAction remembered_set_action,
- SmiCheck smi_check) {
+void MacroAssembler::RecordWrite(
+ Register object,
+ Register address,
+ Register value,
+ RAStatus ra_status,
+ SaveFPRegsMode fp_mode,
+ RememberedSetAction remembered_set_action,
+ SmiCheck smi_check,
+ PointersToHereCheck pointers_to_here_check_for_value) {
ASSERT(!AreAliased(object, address, value, t8));
ASSERT(!AreAliased(object, address, value, t9));
@@ -255,6 +334,11 @@
Assert(
eq, kWrongAddressOrValuePassedToRecordWrite, at, Operand(value));
}
+
+ 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();
@@ -269,11 +353,13 @@
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,
=======================================
--- /trunk/src/mips/macro-assembler-mips.h Wed Jun 4 00:06:13 2014 UTC
+++ /trunk/src/mips/macro-assembler-mips.h Wed Jun 4 07:18:06 2014 UTC
@@ -71,6 +71,10 @@
enum RememberedSetAction { EMIT_REMEMBERED_SET, OMIT_REMEMBERED_SET };
enum SmiCheck { INLINE_SMI_CHECK, OMIT_SMI_CHECK };
+enum PointersToHereCheck {
+ kPointersToHereMaybeInteresting,
+ kPointersToHereAreAlwaysInteresting
+};
enum RAStatus { kRAHasNotBeenSaved, kRAHasBeenSaved };
Register GetRegisterThatIsNotOneOf(Register reg1,
@@ -365,7 +369,9 @@
RAStatus ra_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).
@@ -377,7 +383,9 @@
RAStatus ra_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,
@@ -385,8 +393,16 @@
ra_status,
save_fp,
remembered_set_action,
- smi_check);
+ smi_check,
+ pointers_to_here_check_for_value);
}
+
+ void RecordWriteForMap(
+ Register object,
+ Register map,
+ Register dst,
+ RAStatus ra_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
@@ -398,7 +414,9 @@
RAStatus ra_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);
//
---------------------------------------------------------------------------
=======================================
--- /trunk/src/version.cc Wed Jun 4 00:06:13 2014 UTC
+++ /trunk/src/version.cc Wed Jun 4 07:18:06 2014 UTC
@@ -35,7 +35,7 @@
#define MAJOR_VERSION 3
#define MINOR_VERSION 27
#define BUILD_NUMBER 19
-#define PATCH_LEVEL 0
+#define PATCH_LEVEL 1
// Use 1 for candidates and 0 otherwise.
// (Boolean macro values are not supported by all preprocessors.)
#define IS_CANDIDATE_VERSION 0
--
--
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