diff options
Diffstat (limited to 'mfbt/Likely.h')
| -rw-r--r-- | mfbt/Likely.h | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/mfbt/Likely.h b/mfbt/Likely.h new file mode 100644 index 0000000..a217e60 --- /dev/null +++ b/mfbt/Likely.h @@ -0,0 +1,22 @@ +/* -*- 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__) && (__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 + +#endif /* mozilla_Likely_h_ */ |