HelenOS sources

_unlikely         242 common/str.c   #define _unlikely(expr) __builtin_expect((expr), false)
_unlikely         242 kernel/generic/common/str.c #define _unlikely(expr) __builtin_expect((expr), false)
_unlikely         242 uspace/lib/c/common/str.c #define _unlikely(expr) __builtin_expect((expr), false)