ARM: Implement native substring copying.

src/arm/macro-assembler-arm.h

 // Copyright 2006-2009 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 15 matching lines @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #ifndef V8_ARM_MACRO_ASSEMBLER_ARM_H_
 #define V8_ARM_MACRO_ASSEMBLER_ARM_H_
 
 #include "assembler.h"
 
 namespace v8 {
 namespace internal {
 
+// ----------------------------------------------------------------------------
+// Static helper functions
+
+// Generate a MemOperand for loading a field from an object.
+static inline MemOperand FieldMemOperand(Register object, int offset) {
+  return MemOperand(object, offset - kHeapObjectTag);
+}
+
 
 // Give alias names to registers
 const Register cp = { 8 };  // JavaScript context pointer
-
+const Register roots = { 10 };  // Roots array pointer.
 
 enum InvokeJSFlags {
   CALL_JS,
   JUMP_JS
 };
 
 
 // MacroAssembler implements a collection of frequently used macros.
 class MacroAssembler: public Assembler {
  public:
@@ skipping 152 matching lines @@
                           Register scratch2,
                           Label* gc_required,
                           AllocationFlags flags);
 
   // Undo allocation in new space. The object passed and objects allocated after
   // it will no longer be allocated. The caller must make sure that no pointers
   // are left to the object(s) no longer allocated as they would be invalid when
   // allocation is undone.
   void UndoAllocationInNewSpace(Register object, Register scratch);
 
+
+  void AllocateTwoByteString(Register result,
+                             Register length,
+                             Register scratch1,
+                             Register scratch2,
+                             Register scratch3,
+                             Label* gc_required);
+  void AllocateAsciiString(Register result,
+                           Register length,
+                           Register scratch1,
+                           Register scratch2,
+                           Register scratch3,
+                           Label* gc_required);
+
+
   // ---------------------------------------------------------------------------
   // Support functions.
 
   // Try to get function prototype of a function and puts the value in
   // the result register. Checks that the function really is a
   // function and jumps to the miss label if the fast checks fail. The
   // function register will be untouched; the other registers may be
   // clobbered.
   void TryGetFunctionPrototype(Register function,
                                Register result,
@@ skipping 14 matching lines @@
 
   // Compare instance type in a map.  map contains a valid map object whose
   // object type should be compared with the given type.  This both
   // sets the flags and leaves the object type in the type_reg register.  It
   // leaves the heap object in the heap_object register unless the heap_object
   // register is the same register as type_reg.
   void CompareInstanceType(Register map,
                            Register type_reg,
                            InstanceType type);
 
+
+  // Load and check the instance type of an object for being a string.
+  // Loads the type into the second argument register.
+  // Returns a condition that will be enabled if the object was a string.
+  Condition IsObjectStringType(Register obj,
+                               Register type) {
+    ldr(type, FieldMemOperand(obj, HeapObject::kMapOffset));
+    ldrb(type, FieldMemOperand(type, Map::kInstanceTypeOffset));
+    tst(type, Operand(kIsNotStringMask));
+    ASSERT_EQ(0, kStringTag);
+    return eq;
+  }
+
+
   inline void BranchOnSmi(Register value, Label* smi_label) {
     tst(value, Operand(kSmiTagMask));
     b(eq, smi_label);
   }
 
   inline void BranchOnNotSmi(Register value, Label* not_smi_label) {
     tst(value, Operand(kSmiTagMask));
     b(ne, not_smi_label);
   }
 
@@ skipping 158 matching lines @@
   int instructions_;  // Number of instructions of the expected patch size.
   int size_;  // Number of bytes of the expected patch size.
   MacroAssembler masm_;  // Macro assembler used to generate the code.
 };
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 
 // -----------------------------------------------------------------------------
 // Static helper functions.
 
-// Generate a MemOperand for loading a field from an object.
-static inline MemOperand FieldMemOperand(Register object, int offset) {
-  return MemOperand(object, offset - kHeapObjectTag);
-}
-
-
 #ifdef GENERATED_CODE_COVERAGE
 #define CODE_COVERAGE_STRINGIFY(x) #x
 #define CODE_COVERAGE_TOSTRING(x) CODE_COVERAGE_STRINGIFY(x)
 #define __FILE_LINE__ __FILE__ ":" CODE_COVERAGE_TOSTRING(__LINE__)
 #define ACCESS_MASM(masm) masm->stop(__FILE_LINE__); masm->
 #else
 #define ACCESS_MASM(masm) masm->
 #endif
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ARM_MACRO_ASSEMBLER_ARM_H_