MIPS: port Link function contexts directly to the previous context.

src/mips/code-stubs-mips.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 149 matching lines @@
   // Setup the object header.
   __ LoadRoot(a2, Heap::kContextMapRootIndex);
   __ sw(a2, FieldMemOperand(v0, HeapObject::kMapOffset));
   __ li(a2, Operand(Smi::FromInt(length)));
   __ sw(a2, FieldMemOperand(v0, FixedArray::kLengthOffset));
 
   // Setup the fixed slots.
   __ li(a1, Operand(Smi::FromInt(0)));
   __ sw(a3, MemOperand(v0, Context::SlotOffset(Context::CLOSURE_INDEX)));
   __ sw(v0, MemOperand(v0, Context::SlotOffset(Context::FCONTEXT_INDEX)));
-  __ sw(a1, MemOperand(v0, Context::SlotOffset(Context::PREVIOUS_INDEX)));
+  __ sw(cp, MemOperand(v0, Context::SlotOffset(Context::PREVIOUS_INDEX)));
   __ sw(a1, MemOperand(v0, Context::SlotOffset(Context::EXTENSION_INDEX)));
 
-  // Copy the global object from the surrounding context.
+  // Copy the global object from the previous context.
   __ lw(a1, MemOperand(cp, Context::SlotOffset(Context::GLOBAL_INDEX)));
   __ sw(a1, MemOperand(v0, Context::SlotOffset(Context::GLOBAL_INDEX)));
 
   // Initialize the rest of the slots to undefined.
   __ LoadRoot(a1, Heap::kUndefinedValueRootIndex);
   for (int i = Context::MIN_CONTEXT_SLOTS; i < length; i++) {
     __ sw(a1, MemOperand(v0, Context::SlotOffset(i)));
   }
 
   // Remove the on-stack argument and return.
@@ skipping 6471 matching lines @@
   __ mov(result, zero_reg);
   __ Ret();
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS