Inline %_ArgumentsLength.

src/arm/codegen-arm.cc

 // Copyright 2010 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 3569 matching lines @@
   __ ldr(r1, MemOperand(r2, StandardFrameConstants::kMarkerOffset));
   __ cmp(r1, Operand(Smi::FromInt(StackFrame::CONSTRUCT)));
   cc_reg_ = eq;
 }
 
 
 void CodeGenerator::GenerateArgumentsLength(ZoneList<Expression*>* args) {
   VirtualFrame::SpilledScope spilled_scope;
   ASSERT(args->length() == 0);
 
-  // Seed the result with the formal parameters count, which will be used
-  // in case no arguments adaptor frame is found below the current frame.
+  Label exit;
+
+  // Get the number of formal parameters.
   __ mov(r0, Operand(Smi::FromInt(scope()->num_parameters())));
 
-  // Call the shared stub to get to the arguments.length.
-  ArgumentsAccessStub stub(ArgumentsAccessStub::READ_LENGTH);
-  frame_->CallStub(&stub, 0);
+  // Check if the calling frame is an arguments adaptor frame.
+  __ ldr(r2, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
+  __ ldr(r3, MemOperand(r2, StandardFrameConstants::kContextOffset));
+  __ cmp(r3, Operand(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
+  __ b(ne, &exit);
+
+  // Arguments adaptor case: Read the arguments length from the
+  // adaptor frame.
+  __ ldr(r0, MemOperand(r2, ArgumentsAdaptorFrameConstants::kLengthOffset));
+
+  __ bind(&exit);
   frame_->EmitPush(r0);
 }
 
 
 void CodeGenerator::GenerateArguments(ZoneList<Expression*>* args) {
   VirtualFrame::SpilledScope spilled_scope;
   ASSERT(args->length() == 1);
 
   // Satisfy contract with ArgumentsAccessStub:
   // Load the key into r1 and the formal parameters count into r0.
@@ skipping 3177 matching lines @@
   __ pop();
   __ pop();
   __ mov(pc, Operand(lr));  // Return.
 
   // Slow-case.  Tail call builtin.
   __ bind(&slow);
   __ InvokeBuiltin(Builtins::INSTANCE_OF, JUMP_JS);
 }
 
 
-void ArgumentsAccessStub::GenerateReadLength(MacroAssembler* masm) {
-  // Check if the calling frame is an arguments adaptor frame.
-  Label adaptor;
-  __ ldr(r2, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
-  __ ldr(r3, MemOperand(r2, StandardFrameConstants::kContextOffset));
-  __ cmp(r3, Operand(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
-  __ b(eq, &adaptor);
-
-  // Nothing to do: The formal number of parameters has already been
-  // passed in register r0 by calling function. Just return it.
-  __ Jump(lr);
-
-  // Arguments adaptor case: Read the arguments length from the
-  // adaptor frame and return it.
-  __ bind(&adaptor);
-  __ ldr(r0, MemOperand(r2, ArgumentsAdaptorFrameConstants::kLengthOffset));
-  __ Jump(lr);
-}
-
-
 void ArgumentsAccessStub::GenerateReadElement(MacroAssembler* masm) {
   // The displacement is the offset of the last parameter (if any)
   // relative to the frame pointer.
   static const int kDisplacement =
       StandardFrameConstants::kCallerSPOffset - kPointerSize;
 
   // Check that the key is a smi.
   Label slow;
   __ BranchOnNotSmi(r1, &slow);
 
@@ skipping 1130 matching lines @@
 
   // Just jump to runtime to add the two strings.
   __ bind(&string_add_runtime);
   __ TailCallRuntime(Runtime::kStringAdd, 2, 1);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal