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Unified Diff: src/ia32/macro-assembler-ia32.cc

Issue 2255004: Cardmarking writebarrier. (Closed)
Patch Set: Created 10 years, 7 months ago
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Index: src/ia32/macro-assembler-ia32.cc
diff --git a/src/ia32/macro-assembler-ia32.cc b/src/ia32/macro-assembler-ia32.cc
index ba2fe2dd4ec273d4455f97c6461121d7ed5e1679..5caa4c41864310376cc77bc38f73ba00d753f979 100644
--- a/src/ia32/macro-assembler-ia32.cc
+++ b/src/ia32/macro-assembler-ia32.cc
@@ -60,49 +60,17 @@ void MacroAssembler::RecordWriteHelper(Register object,
bind(&not_in_new_space);
}
- Label fast;
-
// Compute the page start address from the heap object pointer, and reuse
// the 'object' register for it.
and_(object, ~Page::kPageAlignmentMask);
- Register page_start = object;
-
- // Compute the bit addr in the remembered set/index of the pointer in the
- // page. Reuse 'addr' as pointer_offset.
- sub(addr, Operand(page_start));
- shr(addr, kObjectAlignmentBits);
- Register pointer_offset = addr;
-
- // If the bit offset lies beyond the normal remembered set range, it is in
- // the extra remembered set area of a large object.
- cmp(pointer_offset, Page::kPageSize / kPointerSize);
- j(less, &fast);
-
- // Adjust 'page_start' so that addressing using 'pointer_offset' hits the
- // extra remembered set after the large object.
-
- // Find the length of the large object (FixedArray).
- mov(scratch, Operand(page_start, Page::kObjectStartOffset
- + FixedArray::kLengthOffset));
- Register array_length = scratch;
-
- // Extra remembered set starts right after the large object (a FixedArray), at
- // page_start + kObjectStartOffset + objectSize
- // where objectSize is FixedArray::kHeaderSize + kPointerSize * array_length.
- // Add the delta between the end of the normal RSet and the start of the
- // extra RSet to 'page_start', so that addressing the bit using
- // 'pointer_offset' hits the extra RSet words.
- lea(page_start,
- Operand(page_start, array_length, times_pointer_size,
- Page::kObjectStartOffset + FixedArray::kHeaderSize
- - Page::kRSetEndOffset));
-
- // NOTE: For now, we use the bit-test-and-set (bts) x86 instruction
- // to limit code size. We should probably evaluate this decision by
- // measuring the performance of an equivalent implementation using
- // "simpler" instructions
- bind(&fast);
- bts(Operand(page_start, Page::kRSetOffset), pointer_offset);
+
+ // Compute number of region covering addr. See Page::GetRegionNumberForAddress
+ // method for more details.
+ and_(addr, Page::kPageAlignmentMask);
+ shr(addr, Page::kRegionSizeLog2);
+
+ // Set dirty mark for region.
+ bts(Operand(object, Page::kDirtyFlagOffset), addr);
}
@@ -130,7 +98,7 @@ void MacroAssembler::InNewSpace(Register object,
}
-// Set the remembered set bit for [object+offset].
+// For page containing |object| mark region covering [object+offset] dirty.
// object is the object being stored into, value is the object being stored.
// If offset is zero, then the scratch register contains the array index into
// the elements array represented as a Smi.
@@ -142,9 +110,8 @@ void MacroAssembler::RecordWrite(Register object, int offset,
// registers are esi.
ASSERT(!object.is(esi) && !value.is(esi) && !scratch.is(esi));
- // First, check if a remembered set write is even needed. The tests below
- // catch stores of Smis and stores into young gen (which does not have space
- // for the remembered set bits).
+ // First, check if a write barrier is even needed. The tests below
+ // catch stores of Smis and stores into young gen.
Label done;
// Skip barrier if writing a smi.
@@ -160,47 +127,19 @@ void MacroAssembler::RecordWrite(Register object, int offset,
ASSERT(IsAligned(offset, kPointerSize) ||
IsAligned(offset + kHeapObjectTag, kPointerSize));
- // We use optimized write barrier code if the word being written to is not in
- // a large object chunk or is in the first page of a large object chunk.
- // We make sure that an offset is inside the right limits whether it is
- // tagged or untagged.
- if ((offset > 0) && (offset < Page::kMaxHeapObjectSize - kHeapObjectTag)) {
- // Compute the bit offset in the remembered set, leave it in 'value'.
- lea(value, Operand(object, offset));
- and_(value, Page::kPageAlignmentMask);
- shr(value, kPointerSizeLog2);
-
- // Compute the page address from the heap object pointer, leave it in
- // 'object'.
- and_(object, ~Page::kPageAlignmentMask);
-
- // NOTE: For now, we use the bit-test-and-set (bts) x86 instruction
- // to limit code size. We should probably evaluate this decision by
- // measuring the performance of an equivalent implementation using
- // "simpler" instructions
- bts(Operand(object, Page::kRSetOffset), value);
+ Register dst = scratch;
+ if (offset != 0) {
+ lea(dst, Operand(object, offset));
} else {
- Register dst = scratch;
- if (offset != 0) {
- lea(dst, Operand(object, offset));
- } else {
- // array access: calculate the destination address in the same manner as
- // KeyedStoreIC::GenerateGeneric. Multiply a smi by 2 to get an offset
- // into an array of words.
- ASSERT_EQ(1, kSmiTagSize);
- ASSERT_EQ(0, kSmiTag);
- lea(dst, Operand(object, dst, times_half_pointer_size,
- FixedArray::kHeaderSize - kHeapObjectTag));
- }
- // If we are already generating a shared stub, not inlining the
- // record write code isn't going to save us any memory.
- if (generating_stub()) {
- RecordWriteHelper(object, dst, value);
- } else {
- RecordWriteStub stub(object, dst, value);
- CallStub(&stub);
- }
+ // Array access: calculate the destination address in the same manner as
+ // KeyedStoreIC::GenerateGeneric. Multiply a smi by 2 to get an offset
+ // into an array of words.
+ ASSERT_EQ(1, kSmiTagSize);
+ ASSERT_EQ(0, kSmiTag);
+ lea(dst, Operand(object, dst, times_half_pointer_size,
+ FixedArray::kHeaderSize - kHeapObjectTag));
}
+ RecordWriteHelper(object, dst, value);
bind(&done);
@@ -1384,6 +1323,7 @@ void MacroAssembler::InvokeFunction(Register fun,
mov(edx, FieldOperand(edi, JSFunction::kSharedFunctionInfoOffset));
mov(esi, FieldOperand(edi, JSFunction::kContextOffset));
mov(ebx, FieldOperand(edx, SharedFunctionInfo::kFormalParameterCountOffset));
+ SmiUntag(ebx);
mov(edx, FieldOperand(edx, SharedFunctionInfo::kCodeOffset));
lea(edx, FieldOperand(edx, Code::kHeaderSize));
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