LIMB_PLACE_VALUE
scarry >>= LIMB_PLACE_VALUE(LIMBPERM(i));
carry >>= LIMB_PLACE_VALUE(LIMBPERM(i));
fill += LIMB_PLACE_VALUE(LIMBPERM(j));
while (fill < LIMB_PLACE_VALUE(LIMBPERM(i)) && j < nbytes) {
fill -= LIMB_PLACE_VALUE(LIMBPERM(i));
buffer >>= LIMB_PLACE_VALUE(LIMBPERM(i));
#define LIMB_MASK(i) (((1) << LIMB_PLACE_VALUE(i)) - 1)
#define LIMB_MASK(i) (((1ULL) << LIMB_PLACE_VALUE(i)) - 1)