Built-in JSON support

src/arm/ic-arm.cc

 // Copyright 2006-2008 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 109 matching lines @@
   __ bind(&done);  // t1 == t0 + 4*index
   __ ldr(r3, FieldMemOperand(t1, kElementsStartOffset + 2 * kPointerSize));
   __ tst(r3, Operand(PropertyDetails::TypeField::mask() << kSmiTagSize));
   __ b(ne, miss);
 
   // Get the value at the masked, scaled index and return.
   __ ldr(t1, FieldMemOperand(t1, kElementsStartOffset + 1 * kPointerSize));
 }
 
 
-// Helper function used to check that a value is either not a function
-// or is loaded if it is a function.
-static void GenerateCheckNonFunctionOrLoaded(MacroAssembler* masm,
-                                             Label* miss,
-                                             Register value,
-                                             Register scratch) {
+// Helper function used to check that a value is either not an object
+// or is loaded if it is an object.
+static void GenerateCheckNonObjectOrLoaded(MacroAssembler* masm,
+                                           Label* miss,
+                                           Register value,
+                                           Register scratch) {
   Label done;
   // Check if the value is a Smi.
   __ tst(value, Operand(kSmiTagMask));
   __ b(eq, &done);
-  // Check if the value is a function.
-  __ ldr(scratch, FieldMemOperand(value, HeapObject::kMapOffset));
-  __ ldrb(scratch, FieldMemOperand(scratch, Map::kInstanceTypeOffset));
-  __ cmp(scratch, Operand(JS_FUNCTION_TYPE));
-  __ b(ne, &done);
   // Check if the function has been loaded.

[Mads Ager (chromium), 2009/04/23 19:09:25]

function -> object

-  __ ldr(scratch,
-         FieldMemOperand(value, JSFunction::kSharedFunctionInfoOffset));
-  __ ldr(scratch,
-         FieldMemOperand(scratch, SharedFunctionInfo::kLazyLoadDataOffset));
-  __ cmp(scratch, Operand(Factory::undefined_value()));
+  __ ldr(scratch, FieldMemOperand(value, JSObject::kMapOffset));
+  __ ldrb(scratch, FieldMemOperand(scratch, Map::kBitField2Offset));
+  __ tst(scratch, Operand(1 << Map::kNeedsLoading));
   __ b(ne, miss);
   __ bind(&done);
 }
 
 
 void LoadIC::GenerateArrayLength(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- r2    : name
   //  -- lr    : return address
   //  -- [sp]  : receiver
@@ skipping 109 matching lines @@
                                  int argc,
                                  bool is_global_object,
                                  Label* miss) {
   // Search dictionary - put result in register r1.
   GenerateDictionaryLoad(masm, miss, r0, r1);
 
   // Check that the value isn't a smi.
   __ tst(r1, Operand(kSmiTagMask));
   __ b(eq, miss);
 
-  // Check that the value is a JSFunction.

[Mads Ager (chromium), 2009/04/23 19:09:25]

We need this JSFunction check.  We invoke r1 below as a function, so we need to
check that it is a function and otherwise go to the runtime system.

That is the reason for not using GenerateCheckNonFunctionOrLoaded here.

[Christian Plesner Hansen, 2009/04/24 08:11:22]

Oh, good point.

-  __ ldr(r0, FieldMemOperand(r1, HeapObject::kMapOffset));
-  __ ldrb(r0, FieldMemOperand(r0, Map::kInstanceTypeOffset));
-  __ cmp(r0, Operand(JS_FUNCTION_TYPE));
-  __ b(ne, miss);
-
   // Check that the function has been loaded.
-  __ ldr(r0, FieldMemOperand(r1, JSFunction::kSharedFunctionInfoOffset));
-  __ ldr(r0, FieldMemOperand(r0, SharedFunctionInfo::kLazyLoadDataOffset));
-  __ cmp(r0, Operand(Factory::undefined_value()));
+  __ ldr(r0, FieldMemOperand(r1, JSObject::kMapOffset));
+  __ ldrb(r0, FieldMemOperand(r0, Map::kBitField2Offset));
+  __ tst(r0, Operand(1 << Map::kNeedsLoading));
   __ b(ne, miss);
 
   // Patch the receiver with the global proxy if necessary.
   if (is_global_object) {
     __ ldr(r2, MemOperand(sp, argc * kPointerSize));
     __ ldr(r2, FieldMemOperand(r2, GlobalObject::kGlobalReceiverOffset));
     __ str(r2, MemOperand(sp, argc * kPointerSize));
   }
 
   // Invoke the function.
@@ skipping 163 matching lines @@
   __ cmp(r1, Operand(JS_GLOBAL_PROXY_TYPE));
   __ b(eq, &global);
 
   // Check for non-global object that requires access check.
   __ ldrb(r3, FieldMemOperand(r3, Map::kBitFieldOffset));
   __ tst(r3, Operand(1 << Map::kIsAccessCheckNeeded));
   __ b(ne, &miss);
 
   __ bind(&probe);
   GenerateDictionaryLoad(masm, &miss, r1, r0);
-  GenerateCheckNonFunctionOrLoaded(masm, &miss, r0, r1);
+  GenerateCheckNonObjectOrLoaded(masm, &miss, r0, r1);
   __ Ret();
 
   // Global object access: Check access rights.
   __ bind(&global);
   __ CheckAccessGlobalProxy(r0, r1, &miss);
   __ b(&probe);
 
   // Cache miss: Restore receiver from stack and jump to runtime.
   __ bind(&miss);
   Generate(masm, ExternalReference(IC_Utility(kLoadIC_Miss)));
@@ skipping 310 matching lines @@
 
   // Perform tail call to the entry.
   __ TailCallRuntime(f, 3);
 }
 
 
 #undef __
 
 
 } }  // namespace v8::internal