CANTMASK2
t->t_hold.__sigbits[2] = FILLSET2 & ~CANTMASK2;
#define MASKSET2 (FILLSET2 & ~CANTMASK2)
set.__sigbits[2] = FILLSET2 & ~CANTMASK2;
t->t_hold.__sigbits[2] = FILLSET2 & ~CANTMASK2;
#if (CANTMASK1 == 0 && CANTMASK2 == 0)
{CANTMASK0, CANTMASK1, CANTMASK2};
(ks)->__sigbits[2] = (us)->__sigbits[2] & (FILLSET2 & ~CANTMASK2))
bits2 &= (FILLSET2 & ~CANTMASK2);