Use iterator, moveNext(), current.

runtime/vm/intrinsifier_x64.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_X64.
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/intrinsifier.h"
 
 #include "vm/assembler.h"
@@ skipping 1387 matching lines @@
   __ j(EQUAL, &is_true, Assembler::kNearJump);
   __ LoadObject(RAX, bool_false);
   __ ret();
   __ Bind(&is_true);
   __ LoadObject(RAX, bool_true);
   __ ret();
   return true;
 }
 
 
-static intptr_t GetOffsetForField(const char* class_name_p,
-                                  const char* field_name_p) {
-  const String& class_name = String::Handle(Symbols::New(class_name_p));
-  const String& field_name = String::Handle(Symbols::New(field_name_p));
-  const Library& core_lib = Library::Handle(Library::CoreLibrary());
-  const Class& cls =
-      Class::Handle(core_lib.LookupClassAllowPrivate(class_name));
-  ASSERT(!cls.IsNull());
-  const Field& field = Field::ZoneHandle(cls.LookupInstanceField(field_name));
-  ASSERT(!field.IsNull());
-  return field.Offset();
-}
-
-
-static const char* kFixedSizeArrayIteratorClassName = "_FixedSizeArrayIterator";
-
-// Class 'FixedSizeArrayIterator':
-//   T next() {
-//     return _array[_pos++];
-//   }
-// Intrinsify: return _array[_pos++];
-// TODO(srdjan): Throw a 'StateError' exception if the iterator
-// has no more elements.
-bool Intrinsifier::FixedSizeArrayIterator_next(Assembler* assembler) {
-  Label fall_through;
-  const intptr_t array_offset =
-      GetOffsetForField(kFixedSizeArrayIteratorClassName, "_array");
-  const intptr_t pos_offset =
-      GetOffsetForField(kFixedSizeArrayIteratorClassName, "_pos");
-  ASSERT((array_offset >= 0) && (pos_offset >= 0));
-  // Receiver is not NULL.
-  __ movq(RAX, Address(RSP, + 1 * kWordSize));  // Receiver.
-  __ movq(RCX, FieldAddress(RAX, pos_offset));  // Field _pos.
-  // '_pos' cannot be greater than array length and therefore is always Smi.
-#if defined(DEBUG)
-  Label pos_ok;
-  __ testq(RCX, Immediate(kSmiTagMask));
-  __ j(ZERO, &pos_ok, Assembler::kNearJump);
-  __ Stop("pos must be Smi");
-  __ Bind(&pos_ok);
-#endif
-  // Check that we are not trying to call 'next' when 'hasNext' is false.
-  __ movq(RAX, FieldAddress(RAX, array_offset));  // Field _array.
-  __ cmpq(RCX, FieldAddress(RAX, Array::length_offset()));  // Range check.
-  __ j(ABOVE_EQUAL, &fall_through, Assembler::kNearJump);
-
-  // RCX is Smi, i.e, times 2.
-  ASSERT(kSmiTagShift == 1);
-  __ movq(RDI, FieldAddress(RAX, RCX, TIMES_4, sizeof(RawArray)));  // Result.
-  const Immediate value = Immediate(reinterpret_cast<int64_t>(Smi::New(1)));
-  __ addq(RCX, value);  // _pos++.
-  __ j(OVERFLOW, &fall_through, Assembler::kNearJump);
-  __ movq(RAX, Address(RSP, + 1 * kWordSize));  // Receiver.
-  __ StoreIntoObjectNoBarrier(RAX,
-                              FieldAddress(RAX, pos_offset),
-                              RCX);  // Store _pos.
-  __ movq(RAX, RDI);
-  __ ret();
-  __ Bind(&fall_through);
-  return false;
-}
-
-
-// Class 'FixedSizeArrayIterator':
-//   bool get hasNext {
-//     return _length > _pos;
-//   }
-bool Intrinsifier::FixedSizeArrayIterator_getHasNext(Assembler* assembler) {
-  Label fall_through, is_true;
-  const Bool& bool_true = Bool::ZoneHandle(Bool::True());
-  const Bool& bool_false = Bool::ZoneHandle(Bool::False());
-  const intptr_t length_offset =
-      GetOffsetForField(kFixedSizeArrayIteratorClassName, "_length");
-  const intptr_t pos_offset =
-      GetOffsetForField(kFixedSizeArrayIteratorClassName, "_pos");
-  __ movq(RAX, Address(RSP, + 1 * kWordSize));     // Receiver.
-  __ movq(RCX, FieldAddress(RAX, length_offset));  // Field _length.
-  __ movq(RAX, FieldAddress(RAX, pos_offset));     // Field _pos.
-  __ movq(RDI, RAX);
-  __ orq(RDI, RCX);
-  __ testq(RDI, Immediate(kSmiTagMask));
-  __ j(NOT_ZERO, &fall_through, Assembler::kNearJump);  // Non-smi _length/_pos.
-  __ cmpq(RCX, RAX);     // _length > _pos.
-  __ j(GREATER, &is_true, Assembler::kNearJump);
-  __ LoadObject(RAX, bool_false);
-  __ ret();
-  __ Bind(&is_true);
-  __ LoadObject(RAX, bool_true);
-  __ ret();
-  __ Bind(&fall_through);
-  return false;
-}
-
-
 bool Intrinsifier::String_getHashCode(Assembler* assembler) {
   Label fall_through;
   __ movq(RAX, Address(RSP, + 1 * kWordSize));  // String object.
   __ movq(RAX, FieldAddress(RAX, String::hash_offset()));
   __ cmpq(RAX, Immediate(0));
   __ j(EQUAL, &fall_through, Assembler::kNearJump);
   __ ret();
   __ Bind(&fall_through);
   // Hash not yet computed.
   return false;
@@ skipping 45 matching lines @@
   __ LoadObject(RAX, bool_true);
   __ ret();
   return true;
 }
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64