SH_CIRCLEQ_PREVP
(void *)head : SH_CIRCLEQ_PREVP(elm, field, type))
SH_CIRCLEQ_PREVP(listelm, field, type)->field.scqe_next;\
if (SH_CIRCLEQ_PREVP(listelm, field, type) == (void *)(head)) \
SH_CIRCLEQ_PREVP(listelm, \
SH_PTR_TO_OFF(SH_CIRCLEQ_PREVP(listelm, \
if (SH_CIRCLEQ_PREVP(elm, field, type) == (void *)(head)) \
SH_CIRCLEQ_PREVP(elm, field, type)->field.scqe_next += \