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 | |
15 | namespace v8 { |
16 | namespace internal { |
17 | |
18 | void 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 | |