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 18 namespace v8 { 19 namespace internal { 20 FlushICache(void * start,size_t size)21 void 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