Use CallBootstrapC stub for leaf native calls.

runtime/vm/stub_code_x64.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/assembler.h"
 #include "vm/compiler.h"
 #include "vm/dart_entry.h"
@@ skipping 176 matching lines @@
   }
 
   // Pass NativeArguments structure by value and call native function.
   __ movq(Address(RSP, isolate_offset), CTX);  // Set isolate in NativeArgs.
   __ movq(Address(RSP, argc_tag_offset), R10);  // Set argc in NativeArguments.
   __ movq(Address(RSP, argv_offset), RAX);  // Set argv in NativeArguments.
   __ leaq(RAX, Address(RBP, 2 * kWordSize));  // Compute return value addr.
   __ movq(Address(RSP, retval_offset), RAX);  // Set retval in NativeArguments.
   __ movq(RDI, RSP);  // Pass the pointer to the NativeArguments.
 
-  // Call native function (setsup scope if not leaf function).
-  Label leaf_call;
-  Label done;
-  __ testq(R10, Immediate(NativeArguments::AutoSetupScopeMask()));
-  __ j(ZERO, &leaf_call);
   __ movq(RSI, RBX);  // Pass pointer to function entrypoint.
   __ call(&NativeEntry::NativeCallWrapperLabel());
-  __ jmp(&done);
-  __ Bind(&leaf_call);
-  __ call(RBX);
-  __ Bind(&done);
 
   // Mark that the isolate is executing Dart code.
   __ movq(Address(CTX, Isolate::vm_tag_offset()),
           Immediate(VMTag::kScriptTagId));
 
   // Reset exit frame information in Isolate structure.
   __ movq(Address(CTX, Isolate::top_exit_frame_info_offset()), Immediate(0));
 
   // Load Context pointer from Isolate structure into R8.
   __ movq(R8, Address(CTX, Isolate::top_context_offset()));
@@ skipping 1594 matching lines @@
 
   __ movq(left, Address(RSP, 2 * kWordSize));
   __ movq(right, Address(RSP, 1 * kWordSize));
   GenerateIdenticalWithNumberCheckStub(assembler, left, right);
   __ ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64