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__)
8#include "src/third_party/valgrind/valgrind.h"
9#endif
10
11#if V8_TARGET_ARCH_X64
12
13#include "src/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