[calls] Consistent call protocol for calls.

src/mips/lithium-codegen-mips.cc

 // Copyright 2012 the V8 project authors. All rights reserved.7
 // 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 3395 matching lines @@
   bool can_invoke_directly =
       dont_adapt_arguments || formal_parameter_count == arity;
 
   Register function_reg = a1;
   LPointerMap* pointers = instr->pointer_map();
 
   if (can_invoke_directly) {
     // Change context.
     __ lw(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) {
-      __ li(a0, Operand(arity));
-    }
+    // Always initialize a0 to the number of actual arguments.
+    __ li(a0, Operand(arity));
 
     // Invoke function.
     __ lw(at, FieldMemOperand(function_reg, JSFunction::kCodeEntryOffset));
     __ Call(at);
 
     // Set up deoptimization.
     RecordSafepointWithLazyDeopt(instr, RECORD_SIMPLE_SAFEPOINT);
   } else {
     SafepointGenerator generator(this, pointers, Safepoint::kLazyDeopt);
     ParameterCount count(arity);
@@ skipping 386 matching lines @@
     }
     generator.AfterCall();
   }
 }
 
 
 void LCodeGen::DoCallJSFunction(LCallJSFunction* instr) {
   DCHECK(ToRegister(instr->function()).is(a1));
   DCHECK(ToRegister(instr->result()).is(v0));
 
-  if (instr->hydrogen()->pass_argument_count()) {
-    __ li(a0, Operand(instr->arity()));
-  }
+  __ li(a0, Operand(instr->arity()));
 
   // Change context.
   __ lw(cp, FieldMemOperand(a1, JSFunction::kContextOffset));
 
   // Load the code entry address
   __ lw(at, FieldMemOperand(a1, JSFunction::kCodeEntryOffset));
   __ Call(at);
 
   RecordSafepointWithLazyDeopt(instr, RECORD_SIMPLE_SAFEPOINT);
 }
@@ skipping 2089 matching lines @@
   __ Push(at, ToRegister(instr->function()));
   CallRuntime(Runtime::kPushBlockContext, 2, instr);
   RecordSafepoint(Safepoint::kNoLazyDeopt);
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8