S24
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 */
GG (b, c, d, a, in[ 0], S24, 3921069994U); /* 20 */
GG (b, c, d, a, in[ 4], S24, 3889429448U); /* 24 */
GG (b, c, d, a, in[ 8], S24, 1163531501U); /* 28 */
GG (b, c, d, a, in[12], S24, 2368359562U); /* 32 */
GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
GG (b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */