40 lines
1.1 KiB
C
40 lines
1.1 KiB
C
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/*
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* Copyright 2012 Facebook, Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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/**
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* Compiler hints to indicate the fast path of an "if" branch: whether
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* the if condition is likely to be true or false.
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*
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* @author Tudor Bosman (tudorb@fb.com)
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*/
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#ifndef FOLLY_BASE_LIKELY_H_
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#define FOLLY_BASE_LIKELY_H_
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#undef LIKELY
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#undef UNLIKELY
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#if defined(__GNUC__) && __GNUC__ >= 4
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#define LIKELY(x) (__builtin_expect((x), 1))
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#define UNLIKELY(x) (__builtin_expect((x), 0))
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#else
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#define LIKELY(x) (x)
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#define UNLIKELY(x) (x)
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#endif
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#endif /* FOLLY_BASE_LIKELY_H_ */
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