gecko-dev/mfbt/Likely.h
2012-12-18 13:22:28 -05:00

23 lines
731 B
C

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
/*
* MOZ_LIKELY and MOZ_UNLIKELY macros to hint to the compiler how a
* boolean predicate should be branch-predicted.
*/
#ifndef mozilla_Likely_h_
#define mozilla_Likely_h_
#if defined(__clang__) || defined(__GNUC__)
# define MOZ_LIKELY(x) (__builtin_expect(!!(x), 1))
# define MOZ_UNLIKELY(x) (__builtin_expect(!!(x), 0))
#else
# define MOZ_LIKELY(x) (!!(x))
# define MOZ_UNLIKELY(x) (!!(x))
#endif
#endif /* mozilla_Likely_h_ */