mfbt/Likely.h
author Boris Zbarsky <bzbarsky@mit.edu>
Wed, 29 Feb 2012 21:40:47 -0500
changeset 90916 857f74eb3947b0343e95fc2632652b3891976074
child 91015 c11552388c8bedab9bbb982938d0c41acddbf2a7
permissions -rw-r--r--
Bug 730100. Add a Bloom filter implementation. r=waldo

/* 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.
 */

#if defined(__clang__) || (defined(__GNUC__) && (__GNUC__ > 2))
#  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