S24
GG ( b, c, d, a, in[ 0], S24, 3921069994UL); /* 20 */
GG ( b, c, d, a, in[ 4], S24, 3889429448UL); /* 24 */
GG ( b, c, d, a, in[ 8], S24, 1163531501UL); /* 28 */
GG ( b, c, d, a, in[12], S24, 2368359562UL); /* 32 */
GG ( b, c, d, a, in[ 0], S24, UL(3921069994)); /* 20 */
GG ( b, c, d, a, in[ 4], S24, UL(3889429448)); /* 24 */
GG ( b, c, d, a, in[ 8], S24, UL(1163531501)); /* 28 */
GG ( b, c, d, a, in[12], S24, UL(2368359562)); /* 32 */
GG (b, c, d, a, x[12], S24); /* 20 */
GG (b, c, d, a, x[13], S24); /* 24 */
GG (b, c, d, a, x[14], S24); /* 28 */
GG (b, c, d, a, x[15], S24); /* 32 */