Version 1.3.3
Fix issue 417: incorrect %t placeholder expansion.
Add .gitignore file similar to Chromium's one.
Fix SConstruct file to build with new logging code for Android.
API: added function to find instance of template in prototype
chain. Inlined Object::IsInstanceOf.
Land change to notify valgrind when we modify code on x86.
Add api call to determine whether a string can be externalized.
Add a write() command to d8.
git-svn-id: http://v8.googlecode.com/svn/trunk@2669 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
diff --git a/src/ia32/macro-assembler-ia32.cc b/src/ia32/macro-assembler-ia32.cc
index de0ef8e..7782aa9 100644
--- a/src/ia32/macro-assembler-ia32.cc
+++ b/src/ia32/macro-assembler-ia32.cc
@@ -54,41 +54,47 @@
Register scratch) {
Label fast;
- // Compute the page address from the heap object pointer, leave it
- // in 'object'.
+ // Compute the page start address from the heap object pointer, and reuse
+ // the 'object' register for it.
masm->and_(object, ~Page::kPageAlignmentMask);
+ Register page_start = object;
- // Compute the bit addr in the remembered set, leave it in "addr".
- masm->sub(addr, Operand(object));
+ // Compute the bit addr in the remembered set/index of the pointer in the
+ // page. Reuse 'addr' as pointer_offset.
+ masm->sub(addr, Operand(page_start));
masm->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.
- masm->cmp(addr, Page::kPageSize / kPointerSize);
+ masm->cmp(pointer_offset, Page::kPageSize / kPointerSize);
masm->j(less, &fast);
- // Adjust 'addr' to be relative to the start of the extra remembered set
- // and the page address in 'object' to be the address of the extra
- // remembered set.
- masm->sub(Operand(addr), Immediate(Page::kPageSize / kPointerSize));
- // Load the array length into 'scratch' and multiply by four to get the
- // size in bytes of the elements.
- masm->mov(scratch, Operand(object, Page::kObjectStartOffset
- + FixedArray::kLengthOffset));
- masm->shl(scratch, kObjectAlignmentBits);
- // Add the page header, array header, and array body size to the page
- // address.
- masm->add(Operand(object), Immediate(Page::kObjectStartOffset
- + FixedArray::kHeaderSize));
- masm->add(object, Operand(scratch));
+ // 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).
+ masm->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 'object', so that addressing the bit using 'pointer_offset'
+ // hits the extra RSet words.
+ masm->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
masm->bind(&fast);
- masm->bts(Operand(object, 0), addr);
+ masm->bts(Operand(page_start, Page::kRSetOffset), pointer_offset);
}