src/platform-tls-win32.h

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#ifndef V8_PLATFORM_TLS_WIN32_H_
#define V8_PLATFORM_TLS_WIN32_H_

#include "checks.h"
#include "globals.h"
#include "win32-headers.h"

namespace v8 {
namespace internal {

#if defined(_WIN32) && !defined(_WIN64)

#define V8_FAST_TLS_SUPPORTED 1

inline intptr_t InternalGetExistingThreadLocal(intptr_t index) {
  const intptr_t kTibInlineTlsOffset = 0xE10;
  const intptr_t kTibExtraTlsOffset = 0xF94;
  const intptr_t kMaxInlineSlots = 64;
  const intptr_t kMaxSlots = kMaxInlineSlots + 1024;
  ASSERT(0 <= index && index < kMaxSlots);
  if (index < kMaxInlineSlots) {
    return static_cast<intptr_t>(__readfsdword(kTibInlineTlsOffset +
                                               kPointerSize * index));
  }
  intptr_t extra = static_cast<intptr_t>(__readfsdword(kTibExtraTlsOffset));
  ASSERT(extra != 0);
  return *reinterpret_cast<intptr_t*>(extra +
                                      kPointerSize * (index - kMaxInlineSlots));
}

#endif

} }  // namespace v8::internal

#endif  // V8_PLATFORM_TLS_WIN32_H_