Line data    Source code

       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     7229349 : 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     7229349 : }
      38             : 
      39             : }  // namespace internal
      40             : }  // namespace v8
      41             : 
      42             : #endif  // V8_TARGET_ARCH_X64