sha512_block_data_order
sha512_block_data_order(c, data, 1);
sha512_block_data_order(c, p, 1);
sha512_block_data_order(c, data, len/sizeof(c->u));
sha512_block_data_order(c, p, 1);
sha512_block_data_order(c, p, 1);
void sha512_block_data_order(SHA512_CTX *ctx, const void *in, size_t num);