Fast-codegen: Arguments object working on all platforms.

src/x64/macro-assembler-x64.cc

 // Copyright 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 2217 matching lines @@
                      no_reg,
                      gc_required,
                      TAG_OBJECT);
 
   // Set the map.
   LoadRoot(kScratchRegister, Heap::kHeapNumberMapRootIndex);
   movq(FieldOperand(result, HeapObject::kMapOffset), kScratchRegister);
 }
 
 
+void MacroAssembler::LoadContext(Register dst, int context_chain_length) {
+  if (context_chain_length > 0) {
+    // Move up the chain of contexts to the context containing the slot.
+    movq(dst, Operand(rsi, Context::SlotOffset(Context::CLOSURE_INDEX)));
+    // Load the function context (which is the incoming, outer context).
+    movq(rax, FieldOperand(rax, JSFunction::kContextOffset));
+    for (int i = 1; i < context_chain_length; i++) {
+      movq(dst, Operand(dst, Context::SlotOffset(Context::CLOSURE_INDEX)));
+      movq(dst, FieldOperand(dst, JSFunction::kContextOffset));
+    }
+    // The context may be an intermediate context, not a function context.
+    movq(dst, Operand(dst, Context::SlotOffset(Context::FCONTEXT_INDEX)));
+  } else {  // context is the current function context.
+    // The context may be an intermediate context, not a function context.
+    movq(dst, Operand(rsi, Context::SlotOffset(Context::FCONTEXT_INDEX)));
+  }
+}
+
+
 CodePatcher::CodePatcher(byte* address, int size)
     : address_(address), size_(size), masm_(address, size + Assembler::kGap) {
   // Create a new macro assembler pointing to the address of the code to patch.
   // The size is adjusted with kGap on order for the assembler to generate size
   // bytes of instructions without failing with buffer size constraints.
   ASSERT(masm_.reloc_info_writer.pos() == address_ + size_ + Assembler::kGap);
 }
 
 
 CodePatcher::~CodePatcher() {
   // Indicate that code has changed.
   CPU::FlushICache(address_, size_);
 
   // Check that the code was patched as expected.
   ASSERT(masm_.pc_ == address_ + size_);
   ASSERT(masm_.reloc_info_writer.pos() == address_ + size_ + Assembler::kGap);
 }
 
 } }  // namespace v8::internal