Project Euler 46 solution optimized using SSE2

http://www.mathblog.dk/project-euler-46-odd-number-prime-square/

Not a hard one to code, but it can be optimized using SSE2 instructions. The code below runs with g++ 4.8.1:

g++ -g -c riddle.cpp -std=c++11 -msse2 -pg
g++ -o riddle.exe riddle.o -pg
objdump -d -M intel -S riddle.o > assembly.txt
riddle
gprof riddle.exe gmon.out > report.txt

And here is the code:

#if defined(__SSE2__)    #include <xmmintrin.h> //SSE    #include <emmintrin.h> //SSE2#endif#include <ctime>#include <cstdio>#include <iostream>#include <chrono>using namespace std;typedef unsigned long UL;#define MAX_PRIME_CNT 1000#define MAX_CNT 10001extern int primes[MAX_PRIME_CNT];bool SquareM[MAX_CNT] = {false};int startPrimeInx[MAX_CNT];#if defined(__SSE2__)    //  Debug only    void printM128I(const __m128i &v)    {        unsigned* p = (unsigned*)&v;        cout << p[0] << ":" << p[1] << ":" << p[2] << ":" << p[3] << endl;    }    //  Calculate a[i] * b[i], with i[0..3]    int sse_v[4] = {0};    inline __m128i pwr2_sse(const int &a, const int &b)    {        sse_v[0] = a; sse_v[2] = b;        __m128i mv = _mm_loadu_si128 ((__m128i *)sse_v);                return _mm_mul_epu32(mv, mv);    }    //  Calculate (a[i] - b[i]) >> 1, with i[0..3]    inline __m128i sub4_and_shl1_sse(int a[4], int *b)    {               __m128i va = _mm_loadu_si128 ((__m128i *)a);                __m128i vp = _mm_loadu_si128 ((__m128i *)b);                                return _mm_srli_epi32(_mm_sub_epi32(va, vp), 1);        }   #endifint main() {       auto start = std::chrono::high_resolution_clock::now();    //  Mark Perfect Square Numbers    int vec4[4] = {0};    for (int i = 0; i < 100; i +=4)    {#if defined(__SSE2__)        __m128i r = pwr2_sse(i, i + 1);             unsigned* val = (unsigned*) &r;        SquareM[val[0]] = SquareM[val[2]] = true;        r = pwr2_sse(i + 2, i + 3);             val = (unsigned*) &r;        SquareM[val[0]] = SquareM[val[2]] = true;   #else               SquareM[ i      *  i     ] =         SquareM[(i + 1) * (i + 1)] =            SquareM[(i + 2) * (i + 2)] =         SquareM[(i + 3) * (i + 3)] = true;          #endif          }    //  Pre-calculate start Prime index    register UL prevPrime, currPrime;    for (int i = 1; i < MAX_PRIME_CNT; i ++)    {               prevPrime = primes[i - 1];        currPrime = primes[i];        startPrimeInx[prevPrime] = -2;        for(int j = prevPrime + 2; j < currPrime; j +=2) // skip all evens            startPrimeInx[j] = i - 1;           }    //  Main Logic    register UL v = 1;    register int offset;    while(v += 2)    {               //register int offset = find1stSmallerPrime(v);         offset = startPrimeInx[v]; // pre-calculate it..                            while(offset >= 0)        {   #if defined(__SSE2__)            //  If we still have more than 4 primes to check,             //  we use SSE2 ins to check 4 primes all together            if(offset > 4)            {                int vv[4] = {v,v,v,v};                                              __m128i r = sub4_and_shl1_sse(vv, primes + offset - 3);                                                         unsigned * pinx = (unsigned *)&r;                               if(SquareM[pinx[3]] || SquareM[pinx[2]] || SquareM[pinx[1]] || SquareM[pinx[0]])                        break;                offset -= 4;            }            else            {                               if(SquareM[(v - primes[offset]) >> 1])  break;                offset--;            }#else            if(SquareM[(v - primes[offset]) >> 1])  break;            offset--;#endif        }           if(offset == -1) break;         }    printf("%lu\n", v);    //  Output time spent in milli-seconds    auto end = std::chrono::high_resolution_clock::now();    std::chrono::duration<double> diff = end-start;    cout << "Time(in second): "<<diff.count() << endl;    return 0;}//  Pre-loaded Primes//  Memory-Performance exchange//  int primes[MAX_PRIME_CNT] = {2,  3,  5,  7, 11, 13, 17, 19, 23, 29 , 31, 37, 41, 43, 47, 53, 59, 61, 67, 71 , 73, 79, 83, 89, 97, 101, 103, 107, 109, 113 , 127, 131, 137, 139, 149, 151, 157, 163, 167, 173 , 179, 181, 191, 193, 197, 199, 211, 223, 227, 229 , 233, 239, 241, 251, 257, 263, 269, 271, 277, 281 , 283, 293, 307, 311, 313, 317, 331, 337, 347, 349 , 353, 359, 367, 373, 379, 383, 389, 397, 401, 409 , 419, 421, 431, 433, 439, 443, 449, 457, 461, 463 , 467, 479, 487, 491, 499, 503, 509, 521, 523, 541 , 547, 557, 563, 569, 571, 577, 587, 593, 599, 601 , 607, 613, 617, 619, 631, 641, 643, 647, 653, 659 , 661, 673, 677, 683, 691, 701, 709, 719, 727, 733 , 739, 743, 751, 757, 761, 769, 773, 787, 797, 809 , 811, 821, 823, 827, 829, 839, 853, 857, 859, 863 , 877, 881, 883, 887, 907, 911, 919, 929, 937, 941 , 947, 953, 967, 971, 977, 983, 991, 997, 1009, 1013 , 1019, 1021, 1031, 1033, 1039, 1049, 1051, 1061, 1063, 1069 , 1087, 1091, 1093, 1097, 1103, 1109, 1117, 1123, 1129, 1151 , 1153, 1163, 1171, 1181, 1187, 1193, 1201, 1213, 1217, 1223 , 1229, 1231, 1237, 1249, 1259, 1277, 1279, 1283, 1289, 1291 , 1297, 1301, 1303, 1307, 1319, 1321, 1327, 1361, 1367, 1373 , 1381, 1399, 1409, 1423, 1427, 1429, 1433, 1439, 1447, 1451 , 1453, 1459, 1471, 1481, 1483, 1487, 1489, 1493, 1499, 1511 , 1523, 1531, 1543, 1549, 1553, 1559, 1567, 1571, 1579, 1583 , 1597, 1601, 1607, 1609, 1613, 1619, 1621, 1627, 1637, 1657 , 1663, 1667, 1669, 1693, 1697, 1699, 1709, 1721, 1723, 1733 , 1741, 1747, 1753, 1759, 1777, 1783, 1787, 1789, 1801, 1811 , 1823, 1831, 1847, 1861, 1867, 1871, 1873, 1877, 1879, 1889 , 1901, 1907, 1913, 1931, 1933, 1949, 1951, 1973, 1979, 1987 , 1993, 1997, 1999, 2003, 2011, 2017, 2027, 2029, 2039, 2053 , 2063, 2069, 2081, 2083, 2087, 2089, 2099, 2111, 2113, 2129 , 2131, 2137, 2141, 2143, 2153, 2161, 2179, 2203, 2207, 2213 , 2221, 2237, 2239, 2243, 2251, 2267, 2269, 2273, 2281, 2287 , 2293, 2297, 2309, 2311, 2333, 2339, 2341, 2347, 2351, 2357 , 2371, 2377, 2381, 2383, 2389, 2393, 2399, 2411, 2417, 2423 , 2437, 2441, 2447, 2459, 2467, 2473, 2477, 2503, 2521, 2531 , 2539, 2543, 2549, 2551, 2557, 2579, 2591, 2593, 2609, 2617 , 2621, 2633, 2647, 2657, 2659, 2663, 2671, 2677, 2683, 2687 , 2689, 2693, 2699, 2707, 2711, 2713, 2719, 2729, 2731, 2741 , 2749, 2753, 2767, 2777, 2789, 2791, 2797, 2801, 2803, 2819 , 2833, 2837, 2843, 2851, 2857, 2861, 2879, 2887, 2897, 2903 , 2909, 2917, 2927, 2939, 2953, 2957, 2963, 2969, 2971, 2999 , 3001, 3011, 3019, 3023, 3037, 3041, 3049, 3061, 3067, 3079 , 3083, 3089, 3109, 3119, 3121, 3137, 3163, 3167, 3169, 3181 , 3187, 3191, 3203, 3209, 3217, 3221, 3229, 3251, 3253, 3257 , 3259, 3271, 3299, 3301, 3307, 3313, 3319, 3323, 3329, 3331 , 3343, 3347, 3359, 3361, 3371, 3373, 3389, 3391, 3407, 3413 , 3433, 3449, 3457, 3461, 3463, 3467, 3469, 3491, 3499, 3511 , 3517, 3527, 3529, 3533, 3539, 3541, 3547, 3557, 3559, 3571 , 3581, 3583, 3593, 3607, 3613, 3617, 3623, 3631, 3637, 3643 , 3659, 3671, 3673, 3677, 3691, 3697, 3701, 3709, 3719, 3727 , 3733, 3739, 3761, 3767, 3769, 3779, 3793, 3797, 3803, 3821 , 3823, 3833, 3847, 3851, 3853, 3863, 3877, 3881, 3889, 3907 , 3911, 3917, 3919, 3923, 3929, 3931, 3943, 3947, 3967, 3989 , 4001, 4003, 4007, 4013, 4019, 4021, 4027, 4049, 4051, 4057 , 4073, 4079, 4091, 4093, 4099, 4111, 4127, 4129, 4133, 4139 , 4153, 4157, 4159, 4177, 4201, 4211, 4217, 4219, 4229, 4231 , 4241, 4243, 4253, 4259, 4261, 4271, 4273, 4283, 4289, 4297 , 4327, 4337, 4339, 4349, 4357, 4363, 4373, 4391, 4397, 4409 , 4421, 4423, 4441, 4447, 4451, 4457, 4463, 4481, 4483, 4493 , 4507, 4513, 4517, 4519, 4523, 4547, 4549, 4561, 4567, 4583 , 4591, 4597, 4603, 4621, 4637, 4639, 4643, 4649, 4651, 4657 , 4663, 4673, 4679, 4691, 4703, 4721, 4723, 4729, 4733, 4751 , 4759, 4783, 4787, 4789, 4793, 4799, 4801, 4813, 4817, 4831 , 4861, 4871, 4877, 4889, 4903, 4909, 4919, 4931, 4933, 4937 , 4943, 4951, 4957, 4967, 4969, 4973, 4987, 4993, 4999, 5003 , 5009, 5011, 5021, 5023, 5039, 5051, 5059, 5077, 5081, 5087 , 5099, 5101, 5107, 5113, 5119, 5147, 5153, 5167, 5171, 5179 , 5189, 5197, 5209, 5227, 5231, 5233, 5237, 5261, 5273, 5279 , 5281, 5297, 5303, 5309, 5323, 5333, 5347, 5351, 5381, 5387 , 5393, 5399, 5407, 5413, 5417, 5419, 5431, 5437, 5441, 5443 , 5449, 5471, 5477, 5479, 5483, 5501, 5503, 5507, 5519, 5521 , 5527, 5531, 5557, 5563, 5569, 5573, 5581, 5591, 5623, 5639 , 5641, 5647, 5651, 5653, 5657, 5659, 5669, 5683, 5689, 5693 , 5701, 5711, 5717, 5737, 5741, 5743, 5749, 5779, 5783, 5791 , 5801, 5807, 5813, 5821, 5827, 5839, 5843, 5849, 5851, 5857 , 5861, 5867, 5869, 5879, 5881, 5897, 5903, 5923, 5927, 5939 , 5953, 5981, 5987, 6007, 6011, 6029, 6037, 6043, 6047, 6053 , 6067, 6073, 6079, 6089, 6091, 6101, 6113, 6121, 6131, 6133 , 6143, 6151, 6163, 6173, 6197, 6199, 6203, 6211, 6217, 6221 , 6229, 6247, 6257, 6263, 6269, 6271, 6277, 6287, 6299, 6301 , 6311, 6317, 6323, 6329, 6337, 6343, 6353, 6359, 6361, 6367 , 6373, 6379, 6389, 6397, 6421, 6427, 6449, 6451, 6469, 6473 , 6481, 6491, 6521, 6529, 6547, 6551, 6553, 6563, 6569, 6571 , 6577, 6581, 6599, 6607, 6619, 6637, 6653, 6659, 6661, 6673 , 6679, 6689, 6691, 6701, 6703, 6709, 6719, 6733, 6737, 6761 , 6763, 6779, 6781, 6791, 6793, 6803, 6823, 6827, 6829, 6833 , 6841, 6857, 6863, 6869, 6871, 6883, 6899, 6907, 6911, 6917 , 6947, 6949, 6959, 6961, 6967, 6971, 6977, 6983, 6991, 6997 , 7001, 7013, 7019, 7027, 7039, 7043, 7057, 7069, 7079, 7103 , 7109, 7121, 7127, 7129, 7151, 7159, 7177, 7187, 7193, 7207, 7211, 7213, 7219, 7229, 7237, 7243, 7247, 7253, 7283, 7297 , 7307, 7309, 7321, 7331, 7333, 7349, 7351, 7369, 7393, 7411 , 7417, 7433, 7451, 7457, 7459, 7477, 7481, 7487, 7489, 7499 , 7507, 7517, 7523, 7529, 7537, 7541, 7547, 7549, 7559, 7561 , 7573, 7577, 7583, 7589, 7591, 7603, 7607, 7621, 7639, 7643 , 7649, 7669, 7673, 7681, 7687, 7691, 7699, 7703, 7717, 7723 , 7727, 7741, 7753, 7757, 7759, 7789, 7793, 7817, 7823, 7829 , 7841, 7853, 7867, 7873, 7877, 7879, 7883, 7901, 7907, 7919 };