Add complete ElementKind information directly to Map for objects with elements.

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 1658 matching lines @@
 
 
 void MacroAssembler::CompareRoot(Register obj,
                                  Heap::RootListIndex index) {
   ASSERT(!obj.is(ip));
   LoadRoot(ip, index);
   cmp(obj, ip);
 }
 
 
+void MacroAssembler::CheckFastElements(Register map,
+                                       Register scratch,
+                                       Label* fail) {
+  ldrb(scratch, FieldMemOperand(map, Map::kInstanceTypeOffset));
+  cmp(scratch, Operand(Map::kMaximumBitField2FastElementValue));

[Mads Ager (chromium), 2011/05/30 11:14:24]

Can we add some sort of STATIC_ASSERT here that will trigger if we change the
order of stuff so that it will no longer be safe to only check the top value?

Something like FAST_ELEMENTS == 0?

[danno, 2011/06/01 22:29:54]

Done.

+  b(hi, fail);
+}
+
+
 void MacroAssembler::CheckMap(Register obj,
                               Register scratch,
                               Handle<Map> map,
                               Label* fail,
                               SmiCheckType smi_check_type) {
   if (smi_check_type == DO_SMI_CHECK) {
     JumpIfSmi(obj, fail);
   }
   ldr(scratch, FieldMemOperand(obj, HeapObject::kMapOffset));
   mov(ip, Operand(map));
@@ skipping 1465 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