__start += ts - cshift; \
this_unit++; \
} \
for (; this_unit < end_unit - 1; this_unit++) { \
__v = _bt_piecewise_lshift(__v, ts); \
__start += ts - cshift; \
this_unit++; \
} \
for (; this_unit < end_unit - 1; this_unit++) { \
__v = _bt_piecewise_lshift(__v, ts); \