root/src/x64/cpu-x64.cc

DEFINITIONS

1. SetUp
2. SupportsCrankshaft
3. FlushICache
4. DebugBreak

// Copyright 2012 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
//       notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
//       copyright notice, this list of conditions and the following
//       disclaimer in the documentation and/or other materials provided
//       with the distribution.
//     * Neither the name of Google Inc. nor the names of its
//       contributors may be used to endorse or promote products derived
//       from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

// CPU specific code for x64 independent of OS goes here.

#if defined(__GNUC__) && !defined(__MINGW64__)
#include "third_party/valgrind/valgrind.h"
#endif

#include "v8.h"

#if defined(V8_TARGET_ARCH_X64)

#include "cpu.h"
#include "macro-assembler.h"

namespace v8 {
namespace internal {

void CPU::SetUp() {
  CpuFeatures::Probe();
}


bool CPU::SupportsCrankshaft() {
  return true;  // Yay!
}


void CPU::FlushICache(void* start, size_t size) {
  // No need to flush the instruction cache on Intel. On Intel instruction
  // cache flushing is only necessary when multiple cores running the same
  // code simultaneously. V8 (and JavaScript) is single threaded and when code
  // is patched on an intel CPU the core performing the patching will have its
  // own instruction cache updated automatically.

  // If flushing of the instruction cache becomes necessary Windows has the
  // API function FlushInstructionCache.

  // By default, valgrind only checks the stack for writes that might need to
  // invalidate already cached translated code.  This leads to random
  // instability when code patches or moves are sometimes unnoticed.  One
  // solution is to run valgrind with --smc-check=all, but this comes at a big
  // performance cost.  We can notify valgrind to invalidate its cache.
#ifdef VALGRIND_DISCARD_TRANSLATIONS
  unsigned res = VALGRIND_DISCARD_TRANSLATIONS(start, size);
  USE(res);
#endif
}


void CPU::DebugBreak() {
#ifdef _MSC_VER
  // To avoid Visual Studio runtime support the following code can be used
  // instead
  // __asm { int 3 }
  __debugbreak();
#else
  asm("int $3");
#endif
}

} }  // namespace v8::internal

#endif  // V8_TARGET_ARCH_X64