Reland arguments access support for inlined functions (r11109,r11118).

src/arm/lithium-codegen-arm.cc

 // Copyright 2012 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 2746 matching lines @@
 
   Handle<Code> ic = isolate()->builtins()->KeyedLoadIC_Initialize();
   CallCode(ic, RelocInfo::CODE_TARGET, instr);
 }
 
 
 void LCodeGen::DoArgumentsElements(LArgumentsElements* instr) {
   Register scratch = scratch0();
   Register result = ToRegister(instr->result());
 
-  // Check if the calling frame is an arguments adaptor frame.
-  Label done, adapted;
-  __ ldr(scratch, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
-  __ ldr(result, MemOperand(scratch, StandardFrameConstants::kContextOffset));
-  __ cmp(result, Operand(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
+  if (instr->from_inlined()) {
+    __ add(result, sp, Operand(-2 * kPointerSize));

[Kevin Millikin (Chromium), 2012/04/11 11:49:18]

add?  sub?

I think it's weird to have this off-by-two in both the inlined and non-inlined
cases.  For the inlined case there is a sub here and then an add at every
element access to compensate.  For the non-inlined case there is an add at every
element access instead of just having one here.

I guess the reason is that ArgumentsLength would then have to change, but the
way we do that seems like it could be better, too.  (Setting a register to
either fp or not fp, then comparing it to fp to see if we set it to fp or not
fp, then issuing a duplicate memory load of caller fp if we have an adaptor....)

[Vyacheslav Egorov (Chromium), 2012/04/11 12:47:28]

Off by one is there to avoid changing access code.

On 2012/04/11 11:49:18, Kevin Millikin wrote:

+  } else {
+    // Check if the calling frame is an arguments adaptor frame.
+    Label done, adapted;
+    __ ldr(scratch, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
+    __ ldr(result, MemOperand(scratch, StandardFrameConstants::kContextOffset));
+    __ cmp(result, Operand(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
 
-  // Result is the frame pointer for the frame if not adapted and for the real
-  // frame below the adaptor frame if adapted.
-  __ mov(result, fp, LeaveCC, ne);
-  __ mov(result, scratch, LeaveCC, eq);
+    // Result is the frame pointer for the frame if not adapted and for the real
+    // frame below the adaptor frame if adapted.
+    __ mov(result, fp, LeaveCC, ne);
+    __ mov(result, scratch, LeaveCC, eq);
+  }
 }
 
 
 void LCodeGen::DoArgumentsLength(LArgumentsLength* instr) {
   Register elem = ToRegister(instr->InputAt(0));
   Register result = ToRegister(instr->result());
 
   Label done;
 
   // If no arguments adaptor frame the number of arguments is fixed.
@@ skipping 113 matching lines @@
   LOperand* argument = instr->InputAt(0);
   if (argument->IsDoubleRegister() || argument->IsDoubleStackSlot()) {
     Abort("DoPushArgument not implemented for double type.");
   } else {
     Register argument_reg = EmitLoadRegister(argument, ip);
     __ push(argument_reg);
   }
 }
 
 
+void LCodeGen::DoPop(LPop* instr) {
+  __ Drop(instr->count());
+}
+
+
 void LCodeGen::DoThisFunction(LThisFunction* instr) {
   Register result = ToRegister(instr->result());
   __ LoadHeapObject(result, instr->hydrogen()->closure());
 }
 
 
 void LCodeGen::DoContext(LContext* instr) {
   Register result = ToRegister(instr->result());
   __ mov(result, cp);
 }
@@ skipping 2225 matching lines @@
   __ sub(scratch, result, Operand(index, LSL, kPointerSizeLog2 - kSmiTagSize));
   __ ldr(result, FieldMemOperand(scratch,
                                  FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal