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#include "src/v8.h"
12
13#if V8_TARGET_ARCH_X64
14
15#include "src/assembler.h"
16#include "src/macro-assembler.h"
17
18namespace v8 {
19namespace internal {
20
21void CpuFeatures::FlushICache(void* start, size_t size) {
22  // No need to flush the instruction cache on Intel. On Intel instruction
23  // cache flushing is only necessary when multiple cores running the same
24  // code simultaneously. V8 (and JavaScript) is single threaded and when code
25  // is patched on an intel CPU the core performing the patching will have its
26  // own instruction cache updated automatically.
27
28  // If flushing of the instruction cache becomes necessary Windows has the
29  // API function FlushInstructionCache.
30
31  // By default, valgrind only checks the stack for writes that might need to
32  // invalidate already cached translated code.  This leads to random
33  // instability when code patches or moves are sometimes unnoticed.  One
34  // solution is to run valgrind with --smc-check=all, but this comes at a big
35  // performance cost.  We can notify valgrind to invalidate its cache.
36#ifdef VALGRIND_DISCARD_TRANSLATIONS
37  unsigned res = VALGRIND_DISCARD_TRANSLATIONS(start, size);
38  USE(res);
39#endif
40}
41
42} }  // namespace v8::internal
43
44#endif  // V8_TARGET_ARCH_X64
45