[calls] Consistent call protocol for calls.

src/arm64/lithium-codegen-arm64.cc

 // Copyright 2013 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/arm64/frames-arm64.h"
 #include "src/arm64/lithium-codegen-arm64.h"
 #include "src/arm64/lithium-gap-resolver-arm64.h"
 #include "src/base/bits.h"
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
@@ skipping 1978 matching lines @@
     // Try to confirm that function_reg (x1) is a tagged pointer.
     __ JumpIfNotSmi(function_reg, &is_not_smi);
     __ Abort(kExpectedFunctionObject);
     __ Bind(&is_not_smi);
   }
 
   if (can_invoke_directly) {
     // Change context.
     __ Ldr(cp, FieldMemOperand(function_reg, JSFunction::kContextOffset));
 
-    // Set the arguments count if adaption is not needed. Assumes that x0 is
-    // available to write to at this point.
-    if (dont_adapt_arguments) {
-      __ Mov(arity_reg, arity);
-    }
+    // Always initialize x0 to the number of actual arguments.
+    __ Mov(arity_reg, arity);
 
     // Invoke function.
     __ Ldr(x10, FieldMemOperand(function_reg, JSFunction::kCodeEntryOffset));
     __ Call(x10);
 
     // Set up deoptimization.
     RecordSafepointWithLazyDeopt(instr, RECORD_SIMPLE_SAFEPOINT);
   } else {
     SafepointGenerator generator(this, pointers, Safepoint::kLazyDeopt);
     ParameterCount count(arity);
@@ skipping 46 matching lines @@
   }
 
   RecordPushedArgumentsDelta(instr->hydrogen()->argument_delta());
 }
 
 
 void LCodeGen::DoCallJSFunction(LCallJSFunction* instr) {
   DCHECK(instr->IsMarkedAsCall());
   DCHECK(ToRegister(instr->function()).is(x1));
 
-  if (instr->hydrogen()->pass_argument_count()) {
-    __ Mov(x0, Operand(instr->arity()));
-  }
+  __ Mov(x0, Operand(instr->arity()));
 
   // Change context.
   __ Ldr(cp, FieldMemOperand(x1, JSFunction::kContextOffset));
 
   // Load the code entry address
   __ Ldr(x10, FieldMemOperand(x1, JSFunction::kCodeEntryOffset));
   __ Call(x10);
 
   RecordSafepointWithLazyDeopt(instr, RECORD_SIMPLE_SAFEPOINT);
   RecordPushedArgumentsDelta(instr->hydrogen()->argument_delta());
@@ skipping 3965 matching lines @@
   Handle<ScopeInfo> scope_info = instr->scope_info();
   __ Push(scope_info);
   __ Push(ToRegister(instr->function()));
   CallRuntime(Runtime::kPushBlockContext, 2, instr);
   RecordSafepoint(Safepoint::kNoLazyDeopt);
 }
 
 
 }  // namespace internal
 }  // namespace v8