root/src/ia32/cpu-ia32.cc

DEFINITIONS

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

// Copyright 2011 the V8 project authors. All rights reserved.
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// modification, are permitted provided that the following conditions are
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//
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// CPU specific code for ia32 independent of OS goes here.

#ifdef __GNUC__
#include "third_party/valgrind/valgrind.h"
#endif

#include "v8.h"

#if defined(V8_TARGET_ARCH_IA32)

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

namespace v8 {
namespace internal {

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


bool CPU::SupportsCrankshaft() {
  return CpuFeatures::IsSupported(SSE2);
}


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_IA32