BATC_BLKBYTES
#define BATC_BLKMASK (BATC_BLKBYTES-1)
#define round_batc(a) trunc_batc((a) + BATC_BLKBYTES - 1)
s_text += BATC_BLKBYTES;
s_data += BATC_BLKBYTES;
for (; sz != 0; sz -= BATC_BLKBYTES, pa += BATC_BLKBYTES) {