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

src/arm/lithium-codegen-arm.cc

Index: src/arm/lithium-codegen-arm.cc
diff --git a/src/arm/lithium-codegen-arm.cc b/src/arm/lithium-codegen-arm.cc
index 7c37e8ee8b2214ae6f9d901f3613c9e6101c86d7..d77d2ed496461e333cf884258a9ad00284d7f325 100644
--- a/src/arm/lithium-codegen-arm.cc
+++ b/src/arm/lithium-codegen-arm.cc
@@ -2764,16 +2764,20 @@ 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);
+  }
 }
 
 
@@ -2907,6 +2911,11 @@ void LCodeGen::DoPushArgument(LPushArgument* instr) {
 }
 
 
+void LCodeGen::DoPop(LPop* instr) {
+  __ Drop(instr->count());
+}
+
+
 void LCodeGen::DoThisFunction(LThisFunction* instr) {
   Register result = ToRegister(instr->result());
   __ LoadHeapObject(result, instr->hydrogen()->closure());