Merge r10187, r10188 from the bleeding_edge to the 3.7 branch.
Rescan cells at the end of mark-sweep. This means they don't need a
write barrier.
Review URL: http://codereview.chromium.org/8816021
------------------------------------------------------------------------
Remove write barriers for cells on x64, ARM and MIPS.
Review URL: http://codereview.chromium.org/8834005
------------------------------------------------------------------------
Review URL: http://codereview.chromium.org/9190007
git-svn-id: http://v8.googlecode.com/svn/branches/3.7@10392 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
diff --git a/src/arm/lithium-codegen-arm.cc b/src/arm/lithium-codegen-arm.cc
index 6bc868e..0a4a691 100644
--- a/src/arm/lithium-codegen-arm.cc
+++ b/src/arm/lithium-codegen-arm.cc
@@ -2266,21 +2266,7 @@
// Store the value.
__ str(value, FieldMemOperand(scratch, JSGlobalPropertyCell::kValueOffset));
-
- // Cells are always in the remembered set.
- if (instr->hydrogen()->NeedsWriteBarrier()) {
- HType type = instr->hydrogen()->value()->type();
- SmiCheck check_needed =
- type.IsHeapObject() ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
- __ RecordWriteField(scratch,
- JSGlobalPropertyCell::kValueOffset,
- value,
- scratch2,
- kLRHasBeenSaved,
- kSaveFPRegs,
- OMIT_REMEMBERED_SET,
- check_needed);
- }
+ // Cells are always rescanned, so no write barrier here.
}
diff --git a/src/arm/stub-cache-arm.cc b/src/arm/stub-cache-arm.cc
index 47778f5..d229ae6 100644
--- a/src/arm/stub-cache-arm.cc
+++ b/src/arm/stub-cache-arm.cc
@@ -2587,15 +2587,7 @@
// Store the value in the cell.
__ str(r0, FieldMemOperand(r4, JSGlobalPropertyCell::kValueOffset));
-
- __ mov(r1, r0);
- __ RecordWriteField(r4,
- JSGlobalPropertyCell::kValueOffset,
- r1,
- r2,
- kLRHasNotBeenSaved,
- kDontSaveFPRegs,
- OMIT_REMEMBERED_SET);
+ // Cells are always rescanned, so no write barrier here.
Counters* counters = masm()->isolate()->counters();
__ IncrementCounter(counters->named_store_global_inline(), 1, r4, r3);
diff --git a/src/ia32/code-stubs-ia32.cc b/src/ia32/code-stubs-ia32.cc
index fbae95c..3a286f0 100644
--- a/src/ia32/code-stubs-ia32.cc
+++ b/src/ia32/code-stubs-ia32.cc
@@ -4540,7 +4540,8 @@
// megamorphic.
__ cmp(ecx, Immediate(UninitializedSentinel(isolate)));
__ j(equal, &initialize, Label::kNear);
- // MegamorphicSentinel is a root so no write-barrier is needed.
+ // MegamorphicSentinel is an immortal immovable object (undefined) so no
+ // write-barrier is needed.
__ mov(FieldOperand(ebx, JSGlobalPropertyCell::kValueOffset),
Immediate(MegamorphicSentinel(isolate)));
__ jmp(&call, Label::kNear);
@@ -4548,14 +4549,7 @@
// An uninitialized cache is patched with the function.
__ bind(&initialize);
__ mov(FieldOperand(ebx, JSGlobalPropertyCell::kValueOffset), edi);
- __ mov(ecx, edi);
- __ RecordWriteField(ebx,
- JSGlobalPropertyCell::kValueOffset,
- ecx,
- edx,
- kDontSaveFPRegs,
- OMIT_REMEMBERED_SET, // Cells are rescanned.
- OMIT_SMI_CHECK);
+ // No need for a write barrier here - cells are rescanned.
__ bind(&call);
}
@@ -4587,6 +4581,8 @@
// non-function case.
__ mov(ebx, Operand(esp, 0));
__ mov(ebx, Operand(ebx, 1));
+ // MegamorphicSentinel is an immortal immovable object (undefined) so no
+ // write barrier is needed.
__ mov(FieldOperand(ebx, JSGlobalPropertyCell::kValueOffset),
Immediate(MegamorphicSentinel(isolate)));
}
diff --git a/src/ia32/lithium-codegen-ia32.cc b/src/ia32/lithium-codegen-ia32.cc
index 8b778f3..aacce59 100644
--- a/src/ia32/lithium-codegen-ia32.cc
+++ b/src/ia32/lithium-codegen-ia32.cc
@@ -2139,20 +2139,7 @@
// Store the value.
__ mov(FieldOperand(object, offset), value);
-
- // Cells are always in the remembered set.
- if (instr->hydrogen()->NeedsWriteBarrier()) {
- HType type = instr->hydrogen()->value()->type();
- SmiCheck check_needed =
- type.IsHeapObject() ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
- __ RecordWriteField(object,
- offset,
- value,
- address,
- kSaveFPRegs,
- OMIT_REMEMBERED_SET,
- check_needed);
- }
+ // Cells are always rescanned, so no write barrier here.
}
diff --git a/src/ia32/stub-cache-ia32.cc b/src/ia32/stub-cache-ia32.cc
index aa8f47a..722d718 100644
--- a/src/ia32/stub-cache-ia32.cc
+++ b/src/ia32/stub-cache-ia32.cc
@@ -2522,23 +2522,9 @@
// Store the value in the cell.
__ mov(cell_operand, eax);
- Label done;
- __ test(eax, Immediate(kSmiTagMask));
- __ j(zero, &done);
-
- __ mov(ecx, eax);
- __ lea(edx, cell_operand);
- // Cells are always in the remembered set.
- __ RecordWrite(ebx, // Object.
- edx, // Address.
- ecx, // Value.
- kDontSaveFPRegs,
- OMIT_REMEMBERED_SET,
- OMIT_SMI_CHECK);
+ // No write barrier here, because cells are always rescanned.
// Return the value (register eax).
- __ bind(&done);
-
Counters* counters = isolate()->counters();
__ IncrementCounter(counters->named_store_global_inline(), 1);
__ ret(0);
diff --git a/src/mark-compact.cc b/src/mark-compact.cc
index 1bca5f6..db5ed0f 100644
--- a/src/mark-compact.cc
+++ b/src/mark-compact.cc
@@ -2100,6 +2100,24 @@
PrepareForCodeFlushing();
+ if (was_marked_incrementally_) {
+ // There is no write barrier on cells so we have to scan them now at the end
+ // of the incremental marking.
+ {
+ HeapObjectIterator cell_iterator(heap()->cell_space());
+ HeapObject* cell;
+ while ((cell = cell_iterator.Next()) != NULL) {
+ ASSERT(cell->IsJSGlobalPropertyCell());
+ if (IsMarked(cell)) {
+ int offset = JSGlobalPropertyCell::kValueOffset;
+ StaticMarkingVisitor::VisitPointer(
+ heap(),
+ reinterpret_cast<Object**>(cell->address() + offset));
+ }
+ }
+ }
+ }
+
RootMarkingVisitor root_visitor(heap());
MarkRoots(&root_visitor);
diff --git a/src/mips/lithium-codegen-mips.cc b/src/mips/lithium-codegen-mips.cc
index 5fe904e..54c6dd6 100644
--- a/src/mips/lithium-codegen-mips.cc
+++ b/src/mips/lithium-codegen-mips.cc
@@ -2141,21 +2141,7 @@
// Store the value.
__ sw(value, FieldMemOperand(scratch, JSGlobalPropertyCell::kValueOffset));
-
- // Cells are always in the remembered set.
- if (instr->hydrogen()->NeedsWriteBarrier()) {
- HType type = instr->hydrogen()->value()->type();
- SmiCheck check_needed =
- type.IsHeapObject() ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
- __ RecordWriteField(scratch,
- JSGlobalPropertyCell::kValueOffset,
- value,
- scratch2,
- kRAHasBeenSaved,
- kSaveFPRegs,
- OMIT_REMEMBERED_SET,
- check_needed);
- }
+ // Cells are always rescanned, so no write barrier here.
}
diff --git a/src/mips/stub-cache-mips.cc b/src/mips/stub-cache-mips.cc
index 76452f0..9f214a3 100644
--- a/src/mips/stub-cache-mips.cc
+++ b/src/mips/stub-cache-mips.cc
@@ -2605,15 +2605,7 @@
// Store the value in the cell.
__ sw(a0, FieldMemOperand(t0, JSGlobalPropertyCell::kValueOffset));
__ mov(v0, a0); // Stored value must be returned in v0.
-
- // This trashes a0 but the value is returned in v0 anyway.
- __ RecordWriteField(t0,
- JSGlobalPropertyCell::kValueOffset,
- a0,
- a2,
- kRAHasNotBeenSaved,
- kDontSaveFPRegs,
- OMIT_REMEMBERED_SET);
+ // Cells are always rescanned, so no write barrier here.
Counters* counters = masm()->isolate()->counters();
__ IncrementCounter(counters->named_store_global_inline(), 1, a1, a3);
diff --git a/src/version.cc b/src/version.cc
index 9b243be..115181e 100644
--- a/src/version.cc
+++ b/src/version.cc
@@ -35,7 +35,7 @@
#define MAJOR_VERSION 3
#define MINOR_VERSION 7
#define BUILD_NUMBER 12
-#define PATCH_LEVEL 16
+#define PATCH_LEVEL 17
// Use 1 for candidates and 0 otherwise.
// (Boolean macro values are not supported by all preprocessors.)
#define IS_CANDIDATE_VERSION 0
diff --git a/src/x64/lithium-codegen-x64.cc b/src/x64/lithium-codegen-x64.cc
index bc9c3ce..623c4b4 100644
--- a/src/x64/lithium-codegen-x64.cc
+++ b/src/x64/lithium-codegen-x64.cc
@@ -2049,25 +2049,7 @@
// Store the value.
__ movq(Operand(address, 0), value);
-
- if (instr->hydrogen()->NeedsWriteBarrier()) {
- Label smi_store;
- HType type = instr->hydrogen()->value()->type();
- if (!type.IsHeapNumber() && !type.IsString() && !type.IsNonPrimitive()) {
- __ JumpIfSmi(value, &smi_store, Label::kNear);
- }
-
- int offset = JSGlobalPropertyCell::kValueOffset - kHeapObjectTag;
- __ lea(object, Operand(address, -offset));
- // Cells are always in the remembered set.
- __ RecordWrite(object,
- address,
- value,
- kSaveFPRegs,
- OMIT_REMEMBERED_SET,
- OMIT_SMI_CHECK);
- __ bind(&smi_store);
- }
+ // Cells are always rescanned, so no write barrier here.
}
diff --git a/src/x64/stub-cache-x64.cc b/src/x64/stub-cache-x64.cc
index 5a81c89..58994f2 100644
--- a/src/x64/stub-cache-x64.cc
+++ b/src/x64/stub-cache-x64.cc
@@ -2370,23 +2370,9 @@
// Store the value in the cell.
__ movq(cell_operand, rax);
- Label done;
- __ JumpIfSmi(rax, &done);
-
- __ movq(rcx, rax);
- __ lea(rdx, cell_operand);
- // Cells are always in the remembered set.
- __ RecordWrite(rbx, // Object.
- rdx, // Address.
- rcx, // Value.
- kDontSaveFPRegs,
- OMIT_REMEMBERED_SET,
- OMIT_SMI_CHECK);
-
+ // Cells are always rescanned, so no write barrier here.
// Return the value (register rax).
- __ bind(&done);
-
Counters* counters = isolate()->counters();
__ IncrementCounter(counters->named_store_global_inline(), 1);
__ ret(0);
