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