Call a stub for the write barrier on ARM. This is a step

src/arm/macro-assembler-arm.cc

 // Copyright 2011 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 464 matching lines @@
   cmp(scratch, Operand(ExternalReference::new_space_start(isolate())));
   b(cond, branch);
 }
 
 
 void MacroAssembler::RecordWriteField(
     Register object,
     int offset,
     Register value,
     Register dst,
+    LinkRegisterStatus lr_status,
     SaveFPRegsMode save_fp,
     RememberedSetAction remembered_set_action,
     SmiCheck smi_check) {
   // First, check if a write barrier is even needed. The tests below
   // catch stores of Smis.
   Label done;
 
   // Skip barrier if writing a smi.
   if (smi_check == INLINE_SMI_CHECK) {
     JumpIfSmi(value, &done);
   }
 
   // Although the object register is tagged, the offset is relative to the start
   // of the object, so so offset must be a multiple of kPointerSize.
   ASSERT(IsAligned(offset, kPointerSize));
 
   add(dst, object, Operand(offset));
   if (emit_debug_code()) {
     Label ok;
     JumpIfNotSmi(dst, &ok);
     stop("Unaligned cell in write barrier");
     bind(&ok);
   }
 
-  RecordWrite(
-      object, dst, value, save_fp, remembered_set_action, OMIT_SMI_CHECK);
+  RecordWrite(object,
+              dst,
+              value,
+              lr_status,
+              save_fp,
+              remembered_set_action,
+              OMIT_SMI_CHECK);
 
   bind(&done);
 
   // Clobber clobbered input registers when running with the debug-code flag
   // turned on to provoke errors.
   if (emit_debug_code()) {
     mov(value, Operand(BitCast<int32_t>(kZapValue + 4)));
     mov(dst, Operand(BitCast<int32_t>(kZapValue + 8)));
   }
 }
 
 
 // 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 scratch,
+                                 Register value,
+                                 LinkRegisterStatus lr_status,
                                  SaveFPRegsMode fp_mode,
                                  RememberedSetAction remembered_set_action,
                                  SmiCheck smi_check) {
   // The compiled code assumes that record write doesn't change the
   // context register, so we check that none of the clobbered
   // registers are cp.
-  ASSERT(!address.is(cp) && !scratch.is(cp));
+  ASSERT(!address.is(cp) && !value.is(cp));
 
   Label done;
 
-  // First, test that the object is not in the new space.  We cannot set
-  // region marks for new space pages.
-  InNewSpace(object, scratch, eq, &done);
+  if (smi_check == INLINE_SMI_CHECK) {
+    ASSERT_EQ(0, kSmiTag);
+    tst(value, Operand(kSmiTagMask));
+    b(eq, &done);
+  }
+
+  CheckPageFlag(value,
+                value,  // Used as scratch.
+                MemoryChunk::POINTERS_TO_HERE_ARE_INTERESTING,
+                eq,
+                &done);
+  CheckPageFlag(object,
+                value,  // Used as scratch.
+                MemoryChunk::POINTERS_FROM_HERE_ARE_INTERESTING,
+                eq,
+                &done);
 
   // Record the actual write.
-  RememberedSetHelper(address, scratch, fp_mode);
+  if (lr_status == kLRHasNotBeenSaved) {
+    push(lr);
+  }
+  RecordWriteStub stub(object, value, address, remembered_set_action, fp_mode);
+  CallStub(&stub);
+  if (lr_status == kLRHasNotBeenSaved) {
+    pop(lr);
+  }
 
   bind(&done);
 
-  // Clobber all input registers when running with the debug-code flag
+  // Clobber clobbered registers when running with the debug-code flag
   // turned on to provoke errors.
   if (emit_debug_code()) {
     mov(address, Operand(BitCast<int32_t>(kZapValue + 12)));
-    mov(scratch, Operand(BitCast<int32_t>(kZapValue + 16)));
+    mov(value, Operand(BitCast<int32_t>(kZapValue + 16)));
   }
 }
 
 
 void MacroAssembler::RememberedSetHelper(Register address,
                                          Register scratch,
-                                         SaveFPRegsMode fp_mode) {
+                                         SaveFPRegsMode fp_mode,
+                                         RememberedSetFinalAction and_then) {
   Label done;
   // Load store buffer top.
   ExternalReference store_buffer =
       ExternalReference::store_buffer_top(isolate());
   mov(ip, Operand(store_buffer));
   ldr(scratch, MemOperand(ip));
   // Store pointer to buffer and increment buffer top.
   str(address, MemOperand(scratch, kPointerSize, PostIndex));
   // Write back new top of buffer.
   str(scratch, MemOperand(ip));
   // Call stub on end of buffer.
   // Check for end of buffer.
   tst(scratch, Operand(StoreBuffer::kStoreBufferOverflowBit));
-  b(eq, &done);
+  if (and_then == kFallThroughAtEnd) {
+    b(eq, &done);
+  } else {
+    ASSERT(and_then == kReturnAtEnd);
+    Ret(ne);
+  }
   push(lr);
   StoreBufferOverflowStub store_buffer_overflow =
       StoreBufferOverflowStub(fp_mode);
   CallStub(&store_buffer_overflow);
   pop(lr);
   bind(&done);
+  if (and_then == kReturnAtEnd) {
+    Ret();
+  }
 }
 
 
 // Push and pop all registers that can hold pointers.
 void MacroAssembler::PushSafepointRegisters() {
   // Safepoints expect a block of contiguous register values starting with r0:
   ASSERT(((1 << kNumSafepointSavedRegisters) - 1) == kSafepointSavedRegisters);
   // Safepoints expect a block of kNumSafepointRegisters values on the
   // stack, so adjust the stack for unsaved registers.
   const int num_unsaved = kNumSafepointRegisters - kNumSafepointSavedRegisters;
@@ skipping 2495 matching lines @@
     MemoryChunk::MemoryChunkFlags flag,
     Condition cc,
     Label* condition_met) {
   and_(scratch, object, Operand(~Page::kPageAlignmentMask));
   ldr(scratch, MemOperand(scratch, MemoryChunk::kFlagsOffset));
   tst(scratch, Operand(1 << flag));
   b(cc, condition_met);
 }
 
 
+void MacroAssembler::IsBlack(Register object,
+                             Register scratch0,
+                             Register scratch1,
+                             Label* is_black) {
+  HasColor(object, scratch0, scratch1, is_black, 1, 0);  // kBlackBitPattern.
+  ASSERT(strcmp(Marking::kBlackBitPattern, "10") == 0);
+}
+
+
+void MacroAssembler::HasColor(Register object,
+                              Register bitmap_scratch,
+                              Register mask_scratch,
+                              Label* has_color,
+                              int first_bit,
+                              int second_bit) {
+  ASSERT(!Aliasing(object, bitmap_scratch, mask_scratch, no_reg));
+
+  GetMarkBits(object, bitmap_scratch, mask_scratch);
+
+  Label other_color, word_boundary;
+  ldr(ip, MemOperand(bitmap_scratch, MemoryChunk::kHeaderSize));
+  tst(ip, Operand(mask_scratch));
+  b(first_bit == 1 ? eq : ne, &other_color);
+  // Shift left 1 by adding.
+  add(mask_scratch, mask_scratch, Operand(mask_scratch), SetCC);
+  b(eq, &word_boundary);
+  tst(ip, Operand(mask_scratch));
+  b(second_bit == 1 ? ne : eq, has_color);
+  jmp(&other_color);
+
+  bind(&word_boundary);
+  ldr(ip, MemOperand(bitmap_scratch, MemoryChunk::kHeaderSize + kPointerSize));
+  tst(ip, Operand(1));
+  b(second_bit == 1 ? ne : eq, has_color);
+  bind(&other_color);
+}
+
+
+void MacroAssembler::GetMarkBits(Register addr_reg,
+                                 Register bitmap_reg,
+                                 Register mask_reg) {
+  ASSERT(!Aliasing(addr_reg, bitmap_reg, mask_reg, no_reg));
+  and_(bitmap_reg, addr_reg, Operand(~Page::kPageAlignmentMask));
+  Ubfx(mask_reg, addr_reg, kPointerSizeLog2, Bitmap::kBitsPerCellLog2);
+  const int kLowBits = kPointerSizeLog2 + Bitmap::kBitsPerCellLog2;
+  Ubfx(ip, addr_reg, kLowBits, kPageSizeBits - kLowBits);
+  add(bitmap_reg, bitmap_reg, Operand(ip, LSL, kPointerSizeLog2));
+  mov(ip, Operand(1));
+  mov(mask_reg, Operand(ip, LSL, mask_reg));
+}
+
+
 void MacroAssembler::ClampUint8(Register output_reg, Register input_reg) {
   Usat(output_reg, 8, Operand(input_reg));
 }
 
 
 void MacroAssembler::ClampDoubleToUint8(Register result_reg,
                                         DoubleRegister input_reg,
                                         DoubleRegister temp_double_reg) {
   Label above_zero;
   Label done;
@@ skipping 29 matching lines @@
                                              Register descriptors) {
   ldr(descriptors,
       FieldMemOperand(map, Map::kInstanceDescriptorsOrBitField3Offset));
   Label not_smi;
   JumpIfNotSmi(descriptors, &not_smi);
   mov(descriptors, Operand(FACTORY->empty_descriptor_array()));
   bind(&not_smi);
 }
 
 
+bool Aliasing(Register r1, Register r2, Register r3, Register r4) {
+  if (r1.is(r2)) return true;
+  if (r1.is(r3)) return true;
+  if (r1.is(r4)) return true;
+  if (r2.is(r3)) return true;
+  if (r2.is(r4)) return true;
+  if (r3.is(r4)) return true;
+  return false;
+}
+
+
 CodePatcher::CodePatcher(byte* address, int instructions)
     : address_(address),
       instructions_(instructions),
       size_(instructions * Assembler::kInstrSize),
       masm_(Isolate::Current(), address, size_ + Assembler::kGap) {
   // Create a new macro assembler pointing to the address of the code to patch.
   // The size is adjusted with kGap on order for the assembler to generate size
   // bytes of instructions without failing with buffer size constraints.
   ASSERT(masm_.reloc_info_writer.pos() == address_ + size_ + Assembler::kGap);
 }
@@ skipping 22 matching lines @@
 void CodePatcher::EmitCondition(Condition cond) {
   Instr instr = Assembler::instr_at(masm_.pc_);
   instr = (instr & ~kCondMask) | cond;
   masm_.emit(instr);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM