rte_branch_prediction.h - Man Page

#define likely(x)   __builtin_expect(!!(x), 1)
#define unlikely(x)   __builtin_expect(!!(x), 0)

Check if a branch is likely to be taken.

This compiler builtin allows the developer to indicate if a branch is likely to be taken. Example:

if (likely(x > 1)) do_stuff();

Definition at line 30 of file rte_branch_prediction.h.

Check if a branch is unlikely to be taken.

This compiler builtin allows the developer to indicate if a branch is unlikely to be taken. Example:

if (unlikely(x < 1)) do_stuff();

Definition at line 47 of file rte_branch_prediction.h.