[calls] Consistent call protocol for calls.

src/arm/lithium-codegen-arm.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/arm/lithium-codegen-arm.h"
 #include "src/arm/lithium-gap-resolver-arm.h"
 #include "src/base/bits.h"
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
 #include "src/cpu-profiler.h"
@@ skipping 3446 matching lines @@
       dont_adapt_arguments || formal_parameter_count == arity;
 
   Register function_reg = r1;
 
   LPointerMap* pointers = instr->pointer_map();
 
   if (can_invoke_directly) {
     // Change context.
     __ ldr(cp, FieldMemOperand(function_reg, JSFunction::kContextOffset));
 
-    // Set r0 to arguments count if adaption is not needed. Assumes that r0
-    // is available to write to at this point.
-    if (dont_adapt_arguments) {
-      __ mov(r0, Operand(arity));
-    }
+    // Always initialize r0 to the number of actual arguments.
+    __ mov(r0, Operand(arity));
 
     // Invoke function.
     __ ldr(ip, FieldMemOperand(function_reg, JSFunction::kCodeEntryOffset));
     __ Call(ip);
 
     // Set up deoptimization.
     RecordSafepointWithLazyDeopt(instr, RECORD_SIMPLE_SAFEPOINT);
   } else {
     SafepointGenerator generator(this, pointers, Safepoint::kLazyDeopt);
     ParameterCount count(arity);
@@ skipping 360 matching lines @@
     }
     generator.AfterCall();
   }
 }
 
 
 void LCodeGen::DoCallJSFunction(LCallJSFunction* instr) {
   DCHECK(ToRegister(instr->function()).is(r1));
   DCHECK(ToRegister(instr->result()).is(r0));
 
-  if (instr->hydrogen()->pass_argument_count()) {
-    __ mov(r0, Operand(instr->arity()));
-  }
+  __ mov(r0, Operand(instr->arity()));
 
   // Change context.
   __ ldr(cp, FieldMemOperand(r1, JSFunction::kContextOffset));
 
   // Load the code entry address
   __ ldr(ip, FieldMemOperand(r1, JSFunction::kCodeEntryOffset));
   __ Call(ip);
 
   RecordSafepointWithLazyDeopt(instr, RECORD_SIMPLE_SAFEPOINT);
 }
@@ skipping 2010 matching lines @@
   __ push(ToRegister(instr->function()));
   CallRuntime(Runtime::kPushBlockContext, 2, instr);
   RecordSafepoint(Safepoint::kNoLazyDeopt);
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8