Fix/implement new write barrier for x64.

src/x64/macro-assembler-x64.cc

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 55 matching lines @@
 void MacroAssembler::CompareRoot(Register with, Heap::RootListIndex index) {
   cmpq(with, Operand(kRootRegister, index << kPointerSizeLog2));
 }
 
 
 void MacroAssembler::CompareRoot(Operand with, Heap::RootListIndex index) {
   LoadRoot(kScratchRegister, index);
   cmpq(with, kScratchRegister);
 }
 
-#ifdef ENABLE_CARDMARKING_WRITE_BARRIER
+
 void MacroAssembler::RecordWriteHelper(Register object,
                                        Register addr,
-                                       Register scratch) {
+                                       Register scratch,
+                                       SaveFPRegsMode save_fp) {
   if (FLAG_debug_code) {
     // Check that the object is not in new space.
     NearLabel not_in_new_space;
     InNewSpace(object, scratch, not_equal, &not_in_new_space);
     Abort("new-space object passed to RecordWriteHelper");
     bind(&not_in_new_space);
   }
 
-  // Compute the page start address from the heap object pointer, and reuse
-  // the 'object' register for it.
-  and_(object, Immediate(~Page::kPageAlignmentMask));
-
-  // Compute number of region covering addr. See Page::GetRegionNumberForAddress
-  // method for more details.
-  shrl(addr, Immediate(Page::kRegionSizeLog2));
-  andl(addr, Immediate(Page::kPageAlignmentMask >> Page::kRegionSizeLog2));
-
-  // Set dirty mark for region.
-  bts(Operand(object, Page::kDirtyFlagOffset), addr);
+  // Load write buffer top.
+  LoadRoot(scratch, Heap::kWriteBufferTopRootIndex);
+  // Store pointer to buffer.
+  movq(Operand(scratch, 0), addr);
+  // Increment buffer top.
+  addq(scratch, Immediate(kPointerSize));
+  // Write back new top of buffer.
+  StoreRoot(scratch, Heap::kWriteBufferTopRootIndex);
+  // Call stub on end of buffer.
+  NearLabel no_overflow;
+  // Check for end of buffer.
+  testq(scratch, Immediate(WriteBuffer::kWriteBufferOverflowBit));
+  j(equal, &no_overflow);
+  WriteBufferOverflowStub write_buffer_overflow =
+      WriteBufferOverflowStub(save_fp);
+  CallStub(&write_buffer_overflow);
+  bind(&no_overflow);
 }
 
 
 void MacroAssembler::RecordWrite(Register object,
                                  int offset,
                                  Register value,
-                                 Register index) {
+                                 Register index,
+                                 SaveFPRegsMode save_fp) {
   // The compiled code assumes that record write doesn't change the
   // context register, so we check that none of the clobbered
   // registers are rsi.
   ASSERT(!object.is(rsi) && !value.is(rsi) && !index.is(rsi));
 
   // First, check if a write barrier is even needed. The tests below
   // catch stores of Smis and stores into young gen.
   Label done;
   JumpIfSmi(value, &done);
 
-  RecordWriteNonSmi(object, offset, value, index);
+  RecordWriteNonSmi(object, offset, value, index, save_fp);
   bind(&done);
 
   // Clobber all input registers when running with the debug-code flag
   // turned on to provoke errors. This clobbering repeats the
   // clobbering done inside RecordWriteNonSmi but it's necessary to
   // avoid having the fast case for smis leave the registers
   // unchanged.
   if (FLAG_debug_code) {
     movq(object, BitCast<int64_t>(kZapValue), RelocInfo::NONE);
     movq(value, BitCast<int64_t>(kZapValue), RelocInfo::NONE);
     movq(index, BitCast<int64_t>(kZapValue), RelocInfo::NONE);
   }
 }
 
 
 void MacroAssembler::RecordWrite(Register object,
                                  Register address,
-                                 Register value) {
+                                 Register value,
+                                 SaveFPRegsMode save_fp) {
   // The compiled code assumes that record write doesn't change the
   // context register, so we check that none of the clobbered
   // registers are esi.
   ASSERT(!object.is(rsi) && !value.is(rsi) && !address.is(rsi));
 
   // First, check if a write barrier is even needed. The tests below
   // catch stores of Smis and stores into young gen.
   Label done;
   JumpIfSmi(value, &done);
 
   InNewSpace(object, value, equal, &done);
 
-  RecordWriteHelper(object, address, value);
+  RecordWriteHelper(object, address, value, save_fp);
 
   bind(&done);
 
   // Clobber all input registers when running with the debug-code flag
   // turned on to provoke errors.
   if (FLAG_debug_code) {
     movq(object, BitCast<int64_t>(kZapValue), RelocInfo::NONE);
     movq(address, BitCast<int64_t>(kZapValue), RelocInfo::NONE);
     movq(value, BitCast<int64_t>(kZapValue), RelocInfo::NONE);
   }
 }
 
 
 void MacroAssembler::RecordWriteNonSmi(Register object,
                                        int offset,
                                        Register scratch,
-                                       Register index) {
+                                       Register index,
+                                       SaveFPRegsMode save_fp) {
   Label done;
 
   if (FLAG_debug_code) {
     NearLabel okay;
     JumpIfNotSmi(object, &okay);
     Abort("MacroAssembler::RecordWriteNonSmi cannot deal with smis");
     bind(&okay);
 
     if (offset == 0) {
       // index must be int32.
@@ skipping 20 matching lines @@
   if (offset != 0) {
     lea(dst, Operand(object, offset));
   } else {
     // array access: calculate the destination address in the same manner as
     // KeyedStoreIC::GenerateGeneric.
     lea(dst, FieldOperand(object,
                           index,
                           times_pointer_size,
                           FixedArray::kHeaderSize));
   }
-  RecordWriteHelper(object, dst, scratch);
+  RecordWriteHelper(object, dst, scratch, save_fp);
 
   bind(&done);
 
   // Clobber all input registers when running with the debug-code flag
   // turned on to provoke errors.
   if (FLAG_debug_code) {
     movq(object, BitCast<int64_t>(kZapValue), RelocInfo::NONE);
     movq(scratch, BitCast<int64_t>(kZapValue), RelocInfo::NONE);
     movq(index, BitCast<int64_t>(kZapValue), RelocInfo::NONE);
   }
 }
-#endif
+
 
 void MacroAssembler::Assert(Condition cc, const char* msg) {
   if (FLAG_debug_code) Check(cc, msg);
 }
 
 
 void MacroAssembler::AssertFastElements(Register elements) {
   if (FLAG_debug_code) {
     NearLabel ok;
     CompareRoot(FieldOperand(elements, HeapObject::kMapOffset),
@@ skipping 2119 matching lines @@
   CPU::FlushICache(address_, size_);
 
   // Check that the code was patched as expected.
   ASSERT(masm_.pc_ == address_ + size_);
   ASSERT(masm_.reloc_info_writer.pos() == address_ + size_ + Assembler::kGap);
 }
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64