[contexts] Place the initial JSArray maps on the native context directly.

src/mips64/macro-assembler-mips64.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <limits.h>  // For LONG_MIN, LONG_MAX.
 
 #if V8_TARGET_ARCH_MIPS64
 
 #include "src/base/division-by-constant.h"
 #include "src/bootstrapper.h"
@@ skipping 5039 matching lines @@
   }
 }
 
 
 void MacroAssembler::LoadTransitionedArrayMapConditional(
     ElementsKind expected_kind,
     ElementsKind transitioned_kind,
     Register map_in_out,
     Register scratch,
     Label* no_map_match) {
+  DCHECK(IsFastElementsKind(expected_kind));
+  DCHECK(IsFastElementsKind(transitioned_kind));
+
   // Check that the function's map is the same as the expected cached map.
-  LoadNativeContextSlot(Context::JS_ARRAY_MAPS_INDEX, scratch);
-  int offset = expected_kind * kPointerSize + FixedArrayBase::kHeaderSize;
-  ld(at, FieldMemOperand(scratch, offset));
+  ld(scratch, NativeContextMemOperand());
+  ld(at, ContextMemOperand(scratch, Context::ArrayMapIndex(expected_kind)));
   Branch(no_map_match, ne, map_in_out, Operand(at));
 
   // Use the transitioned cached map.
-  offset = transitioned_kind * kPointerSize +
-      FixedArrayBase::kHeaderSize;
-  ld(map_in_out, FieldMemOperand(scratch, offset));
+  ld(map_in_out,
+     ContextMemOperand(scratch, Context::ArrayMapIndex(transitioned_kind)));
 }
 
 
 void MacroAssembler::LoadNativeContextSlot(int index, Register dst) {
   ld(dst, NativeContextMemOperand());
   ld(dst, ContextMemOperand(dst, index));
 }
 
 
 void MacroAssembler::LoadGlobalFunctionInitialMap(Register function,
@@ skipping 1219 matching lines @@
   if (mag.shift > 0) sra(result, result, mag.shift);
   srl(at, dividend, 31);
   Addu(result, result, Operand(at));
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_MIPS64