[calls] Consistent call protocol for calls.

src/ia32/lithium-codegen-ia32.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.
 
 #if V8_TARGET_ARCH_IA32
 
 #include "src/base/bits.h"
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
 #include "src/codegen.h"
@@ skipping 3322 matching lines @@
       formal_parameter_count == SharedFunctionInfo::kDontAdaptArgumentsSentinel;
   bool can_invoke_directly =
       dont_adapt_arguments || formal_parameter_count == arity;
 
   Register function_reg = edi;
 
   if (can_invoke_directly) {
     // Change context.
     __ mov(esi, FieldOperand(function_reg, JSFunction::kContextOffset));
 
-    // Set eax to arguments count if adaption is not needed. Assumes that eax
-    // is available to write to at this point.
-    if (dont_adapt_arguments) {
-      __ mov(eax, arity);
-    }
+    // Always initialize eax to the number of actual arguments.
+    __ mov(eax, arity);
 
     // Invoke function directly.
     if (function.is_identical_to(info()->closure())) {
       __ CallSelf();
     } else {
       __ call(FieldOperand(function_reg, JSFunction::kCodeEntryOffset));
     }
     RecordSafepointWithLazyDeopt(instr, RECORD_SIMPLE_SAFEPOINT);
   } else {
     // We need to adapt arguments.
@@ skipping 41 matching lines @@
     }
     generator.AfterCall();
   }
 }
 
 
 void LCodeGen::DoCallJSFunction(LCallJSFunction* instr) {
   DCHECK(ToRegister(instr->function()).is(edi));
   DCHECK(ToRegister(instr->result()).is(eax));
 
-  if (instr->hydrogen()->pass_argument_count()) {
-    __ mov(eax, instr->arity());
-  }
+  __ mov(eax, instr->arity());
 
   // Change context.
   __ mov(esi, FieldOperand(edi, JSFunction::kContextOffset));
 
   bool is_self_call = false;
   if (instr->hydrogen()->function()->IsConstant()) {
     HConstant* fun_const = HConstant::cast(instr->hydrogen()->function());
     Handle<JSFunction> jsfun =
       Handle<JSFunction>::cast(fun_const->handle(isolate()));
     is_self_call = jsfun.is_identical_to(info()->closure());
@@ skipping 2332 matching lines @@
   RecordSafepoint(Safepoint::kNoLazyDeopt);
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_IA32