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

src/arm/full-codegen-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 185 matching lines @@
       if (slot != NULL && slot->type() == Slot::CONTEXT) {
         int parameter_offset = StandardFrameConstants::kCallerSPOffset +
             (num_parameters - 1 - i) * kPointerSize;
         // Load parameter from stack.
         __ ldr(r0, MemOperand(fp, parameter_offset));
         // Store it in the context.
         MemOperand target = ContextOperand(cp, slot->index());
         __ str(r0, target);
 
         // Update the write barrier.
-        __ RecordWriteContextSlot(cp, target.offset(), r0, r3, kDontSaveFPRegs);
+        __ RecordWriteContextSlot(
+            cp, target.offset(), r0, r3, kLRHasBeenSaved, kDontSaveFPRegs);
       }
     }
   }
 
   Variable* arguments = scope()->arguments();
   if (arguments != NULL) {
     // Function uses arguments object.
     Comment cmnt(masm_, "[ Allocate arguments object");
     if (!function_in_register) {
       // Load this again, if it's used by the local context below.
@@ skipping 424 matching lines @@
                              Register src,
                              Register scratch1,
                              Register scratch2) {
   ASSERT(dst->type() != Slot::LOOKUP);  // Not yet implemented.
   ASSERT(!scratch1.is(src) && !scratch2.is(src));
   MemOperand location = EmitSlotSearch(dst, scratch1);
   __ str(src, location);
 
   // Emit the write barrier code if the location is in the heap.
   if (dst->type() == Slot::CONTEXT) {
-    __ RecordWriteContextSlot(
-        scratch1, location.offset(), src, scratch2, kDontSaveFPRegs);
+    __ RecordWriteContextSlot(scratch1,
+                              location.offset(),
+                              src,
+                              scratch2,
+                              kLRHasBeenSaved,
+                              kDontSaveFPRegs);
   }
 }
 
 
 void FullCodeGenerator::PrepareForBailoutBeforeSplit(State state,
                                                      bool should_normalize,
                                                      Label* if_true,
                                                      Label* if_false) {
   // Only prepare for bailouts before splits if we're in a test
   // context. Otherwise, we let the Visit function deal with the
@@ skipping 59 matching lines @@
         } else if (function != NULL) {
           VisitForAccumulatorValue(function);
           MemOperand target = ContextOperand(cp, slot->index());
           __ str(result_register(), target);
 
           // We know that we have written a function, which is not a smi.
           __ RecordWriteContextSlot(cp,
                                     target.offset(),
                                     result_register(),
                                     r2,
+                                    kLRHasBeenSaved,
                                     kDontSaveFPRegs,
                                     EMIT_REMEMBERED_SET,
                                     OMIT_SMI_CHECK);
         }
         break;
 
       case Slot::LOOKUP: {
         __ mov(r2, Operand(variable->name()));
         // Declaration nodes are always introduced in one of two modes.
         ASSERT(mode == Variable::VAR ||
@@ skipping 804 matching lines @@
     VisitForAccumulatorValue(subexpr);
 
     // Store the subexpression value in the array's elements.
     __ ldr(r1, MemOperand(sp));  // Copy of array literal.
     __ ldr(r1, FieldMemOperand(r1, JSObject::kElementsOffset));
     int offset = FixedArray::kHeaderSize + (i * kPointerSize);
     __ str(result_register(), FieldMemOperand(r1, offset));
 
     // Update the write barrier for the array store with r0 as the scratch
     // register.
-    __ RecordWriteField(r1, offset, result_register(), r2, kDontSaveFPRegs);
+    __ RecordWriteField(
+        r1, offset, result_register(), r2, kLRHasBeenSaved, kDontSaveFPRegs);
 
     PrepareForBailoutForId(expr->GetIdForElement(i), NO_REGISTERS);
   }
 
   if (result_saved) {
     context()->PlugTOS();
   } else {
     context()->Plug(r0);
   }
 }
@@ skipping 361 matching lines @@
         break;
       case Slot::CONTEXT: {
         __ ldr(r1, ContextOperand(cp, Context::FCONTEXT_INDEX));
         __ ldr(r2, ContextOperand(r1, slot->index()));
         __ LoadRoot(ip, Heap::kTheHoleValueRootIndex);
         __ cmp(r2, ip);
         __ b(ne, &skip);
         MemOperand target = ContextOperand(r1, slot->index());
         __ str(r0, target);
         __ mov(r3, r0);  // Preserve the stored value in r0.
-        __ RecordWriteContextSlot(r1, target.offset(), r3, r2, kDontSaveFPRegs);
+        __ RecordWriteContextSlot(
+            r1, target.offset(), r3, r2, kLRHasBeenSaved, kDontSaveFPRegs);
         break;
       }
       case Slot::LOOKUP:
         __ push(r0);
         __ mov(r0, Operand(slot->var()->name()));
         __ Push(cp, r0);  // Context and name.
         __ CallRuntime(Runtime::kInitializeConstContextSlot, 3);
         break;
     }
     __ bind(&skip);
 
   } else if (var->mode() != Variable::CONST) {
     // Perform the assignment for non-const variables.  Const assignments
     // are simply skipped.
     Slot* slot = var->AsSlot();
     switch (slot->type()) {
       case Slot::PARAMETER:
       case Slot::LOCAL:
         // Perform the assignment.
         __ str(result_register(), MemOperand(fp, SlotOffset(slot)));
         break;
 
       case Slot::CONTEXT: {
         MemOperand target = EmitSlotSearch(slot, r1);
         // Perform the assignment and issue the write barrier.
         __ str(result_register(), target);
         // The value of the assignment is in result_register().  RecordWrite
         // clobbers its second and third register arguments.
         __ mov(r3, result_register());
-        __ RecordWriteContextSlot(r1, target.offset(), r3, r2, kDontSaveFPRegs);
+        __ RecordWriteContextSlot(
+            r1, target.offset(), r3, r2, kLRHasBeenSaved, kDontSaveFPRegs);
         break;
       }
 
       case Slot::LOOKUP:
         // Call the runtime for the assignment.
         __ push(r0);  // Value.
         __ mov(r1, Operand(slot->var()->name()));
         __ mov(r0, Operand(Smi::FromInt(strict_mode_flag())));
         __ Push(cp, r1, r0);  // Context, name, strict mode.
         __ CallRuntime(Runtime::kStoreContextSlot, 4);
@@ skipping 983 matching lines @@
 
   // If the object is not a value type, return the value.
   __ CompareObjectType(r1, r2, r2, JS_VALUE_TYPE);
   __ b(ne, &done);
 
   // Store the value.
   __ str(r0, FieldMemOperand(r1, JSValue::kValueOffset));
   // Update the write barrier.  Save the value as it will be
   // overwritten by the write barrier code and is needed afterward.
   __ mov(r2, r0);
-  __ RecordWriteField(r1, JSValue::kValueOffset, r2, r3, kDontSaveFPRegs);
+  __ RecordWriteField(
+      r1, JSValue::kValueOffset, r2, r3, kLRHasBeenSaved, kDontSaveFPRegs);
 
   __ bind(&done);
   context()->Plug(r0);
 }
 
 
 void FullCodeGenerator::EmitNumberToString(ZoneList<Expression*>* args) {
   ASSERT_EQ(args->length(), 1);
 
   // Load the argument on the stack and call the stub.
@@ skipping 275 matching lines @@
 
   Label no_remembered_set;
   __ CheckPageFlag(elements,
                    scratch1,
                    MemoryChunk::SCAN_ON_SCAVENGE,
                    ne,
                    &no_remembered_set);
   // Possible optimization: do a check that both values are Smis
   // (or them and test against Smi mask.)
 
-  __ RememberedSetHelper(index1, scratch2, kDontSaveFPRegs);
-  __ RememberedSetHelper(index2, scratch2, kDontSaveFPRegs);
+  __ RememberedSetHelper(
+      index1, scratch2, kDontSaveFPRegs, MacroAssembler::kFallThroughAtEnd);
+  __ RememberedSetHelper(
+      index2, scratch2, kDontSaveFPRegs, MacroAssembler::kFallThroughAtEnd);
 
   __ bind(&no_remembered_set);
   // We are done. Drop elements from the stack, and return undefined.
   __ Drop(3);
   __ LoadRoot(r0, Heap::kUndefinedValueRootIndex);
   __ jmp(&done);
 
   __ bind(&slow_case);
   __ CallRuntime(Runtime::kSwapElements, 3);
 
@@ skipping 1094 matching lines @@
   __ mov(r1, Operand(r1, ASR, 1));  // Un-smi-tag value.
   __ add(pc, r1, Operand(masm_->CodeObject()));
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM