1// Copyright 2012 the V8 project authors. All rights reserved. 2// Use of this source code is governed by a BSD-style license that can be 3// found in the LICENSE file. 4 5// CPU specific code for x64 independent of OS goes here. 6 7#if defined(__GNUC__) && !defined(__MINGW64__) && !defined(GOOGLE3) 8#include "src/third_party/valgrind/valgrind.h" 9#endif 10 11#if V8_TARGET_ARCH_X64 12 13#include "src/codegen/cpu-features.h" 14 15namespace v8 { 16namespace internal { 17 18void CpuFeatures::FlushICache(void* start, size_t size) { 19 // No need to flush the instruction cache on Intel. On Intel instruction 20 // cache flushing is only necessary when multiple cores running the same 21 // code simultaneously. V8 (and JavaScript) is single threaded and when code 22 // is patched on an intel CPU the core performing the patching will have its 23 // own instruction cache updated automatically. 24 25 // If flushing of the instruction cache becomes necessary Windows has the 26 // API function FlushInstructionCache. 27 28 // By default, valgrind only checks the stack for writes that might need to 29 // invalidate already cached translated code. This leads to random 30 // instability when code patches or moves are sometimes unnoticed. One 31 // solution is to run valgrind with --smc-check=all, but this comes at a big 32 // performance cost. We can notify valgrind to invalidate its cache. 33#ifdef VALGRIND_DISCARD_TRANSLATIONS 34 unsigned res = VALGRIND_DISCARD_TRANSLATIONS(start, size); 35 USE(res); 36#endif 37} 38 39} // namespace internal 40} // namespace v8 41 42#endif // V8_TARGET_ARCH_X64 43