[dcl.attr.likelihood] (original) (raw)

Recommended practice:The use of the likely attribute is intended to allow implementations to optimize for the case where paths of execution including it are arbitrarily more likely than any alternative path of execution that does not include such an attribute on a statement or label.

The use of the unlikely attribute is intended to allow implementations to optimize for the case where paths of execution including it are arbitrarily more unlikely than any alternative path of execution that does not include such an attribute on a statement or label.

A path of execution includes a label if and only if it contains a jump to that label.

[ Note

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Excessive usage of either of these attributes is liable to result in performance degradation.

— end note

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