SA_BLOCK_MASK
& SA_BLOCK_MASK];
r = p == NULL ? NULL : p[n & SA_BLOCK_MASK];
i = (posn >> (OPENSSL_SA_BLOCK_BITS * level)) & SA_BLOCK_MASK;
p += posn & SA_BLOCK_MASK;
idx = (idx & ~SA_BLOCK_MASK) | n;