To fully support hydrogen code stubs which accept a variable number of arguments,

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 2932 matching lines @@
     BitVector::Iterator save_iterator(doubles);
     int count = 0;
     while (!save_iterator.Done()) {
       __ vldr(DwVfpRegister::FromAllocationIndex(save_iterator.Current()),
                MemOperand(sp, count * kDoubleSize));
       save_iterator.Advance();
       count++;
     }
   }
   if (NeedsEagerFrame()) {
-    int32_t sp_delta = (GetParameterCount() + 1) * kPointerSize;
     __ mov(sp, fp);
     __ ldm(ia_w, sp, fp.bit() | lr.bit());
-    if (!info()->IsStub()) {
-      __ add(sp, sp, Operand(sp_delta));
+
+    if (instr->has_constant_parameter_count()) {
+      int parameter_count = ToInteger32(instr->constant_parameter_count());
+      int32_t sp_delta = (parameter_count + 1) * kPointerSize;
+      if (sp_delta != 0) {
+        __ add(sp, sp, Operand(sp_delta));
+      }
+    } else {
+      Register reg = ToRegister(instr->parameter_count());
+      __ add(reg, reg, Operand(1));
+      __ add(sp, sp, Operand(reg, LSL, kPointerSizeLog2));
     }
   }
   __ Jump(lr);
 }
 
 
 void LCodeGen::DoLoadGlobalCell(LLoadGlobalCell* instr) {
   Register result = ToRegister(instr->result());
   __ mov(ip, Operand(Handle<Object>(instr->hydrogen()->cell())));
   __ ldr(result, FieldMemOperand(ip, JSGlobalPropertyCell::kValueOffset));
@@ skipping 3423 matching lines @@
   __ sub(scratch, result, Operand(index, LSL, kPointerSizeLog2 - kSmiTagSize));
   __ ldr(result, FieldMemOperand(scratch,
                                  FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal