bart | 0aeb186 | 2008-03-10 19:26:42 +0000 | [diff] [blame] | 1 | /** An OpenMP example. |
| 2 | * Based on the example listed on the following web page: |
| 3 | * http://developers.sun.com/sunstudio/downloads/ssx/tha/tha_using.html |
| 4 | */ |
| 5 | |
| 6 | |
| 7 | #include <assert.h> |
| 8 | #include <math.h> |
| 9 | #include <omp.h> |
| 10 | #include <stdio.h> |
| 11 | #include <stdlib.h> |
bart | 72ab1ff | 2008-03-12 16:48:07 +0000 | [diff] [blame] | 12 | #include <unistd.h> // getopt() |
bart | 8f822af | 2009-06-08 18:20:42 +0000 | [diff] [blame] | 13 | #include "../../drd/drd.h" |
bart | 0aeb186 | 2008-03-10 19:26:42 +0000 | [diff] [blame] | 14 | |
| 15 | |
| 16 | static int is_prime(int* const pflag, int v) |
| 17 | { |
| 18 | int i; |
| 19 | int bound = floor(sqrt ((double)v)) + 1; |
| 20 | |
| 21 | for (i = 2; i < bound; i++) |
| 22 | { |
| 23 | /* No need to check against known composites */ |
| 24 | if (!pflag[i]) |
| 25 | continue; |
| 26 | if (v % i == 0) |
| 27 | { |
| 28 | pflag[v] = 0; |
| 29 | return 0; |
| 30 | } |
| 31 | } |
| 32 | return (v > 1); |
| 33 | } |
| 34 | |
| 35 | int main(int argc, char **argv) |
| 36 | { |
| 37 | int i; |
| 38 | int total = 0; |
bart | 8f822af | 2009-06-08 18:20:42 +0000 | [diff] [blame] | 39 | int trace_total = 0; |
bart | 72ab1ff | 2008-03-12 16:48:07 +0000 | [diff] [blame] | 40 | int silent = 0; |
| 41 | int n; |
| 42 | int num_threads = 2; |
| 43 | int optchar; |
bart | 0aeb186 | 2008-03-10 19:26:42 +0000 | [diff] [blame] | 44 | int* primes; |
| 45 | int* pflag; |
| 46 | |
bart | 8f822af | 2009-06-08 18:20:42 +0000 | [diff] [blame] | 47 | while ((optchar = getopt(argc, argv, "qt:v")) != EOF) |
bart | 72ab1ff | 2008-03-12 16:48:07 +0000 | [diff] [blame] | 48 | { |
| 49 | switch (optchar) |
| 50 | { |
bart | 8f822af | 2009-06-08 18:20:42 +0000 | [diff] [blame] | 51 | case 'q': |
| 52 | silent = 1; |
| 53 | break; |
| 54 | case 't': |
| 55 | num_threads = atoi(optarg); |
| 56 | break; |
| 57 | case 'v': |
| 58 | trace_total = 1; |
| 59 | break; |
bart | 72ab1ff | 2008-03-12 16:48:07 +0000 | [diff] [blame] | 60 | default: |
| 61 | fprintf(stderr, "Error: unknown option '%c'.\n", optchar); |
| 62 | return 1; |
| 63 | } |
| 64 | } |
| 65 | |
| 66 | if (optind + 1 != argc) |
| 67 | { |
| 68 | fprintf(stderr, "Error: wrong number of arguments.\n"); |
bart | cfe9672 | 2008-07-01 13:16:23 +0000 | [diff] [blame] | 69 | return 1; |
bart | 72ab1ff | 2008-03-12 16:48:07 +0000 | [diff] [blame] | 70 | } |
| 71 | n = atoi(argv[optind]); |
| 72 | |
bart | 0aeb186 | 2008-03-10 19:26:42 +0000 | [diff] [blame] | 73 | // Not the most user-friendly way to do error checking, but better than |
| 74 | // nothing. |
| 75 | assert(n > 2); |
| 76 | assert(num_threads >= 1); |
| 77 | |
| 78 | primes = malloc(n * sizeof(primes[0])); |
| 79 | pflag = malloc(n * sizeof(pflag[0])); |
| 80 | |
| 81 | omp_set_num_threads(num_threads); |
| 82 | omp_set_dynamic(0); |
| 83 | |
bart | 0aeb186 | 2008-03-10 19:26:42 +0000 | [diff] [blame] | 84 | for (i = 0; i < n; i++) { |
| 85 | pflag[i] = 1; |
| 86 | } |
| 87 | |
bart | 8f822af | 2009-06-08 18:20:42 +0000 | [diff] [blame] | 88 | if (trace_total) |
| 89 | DRD_TRACE_VAR(total); |
| 90 | |
bart | 0aeb186 | 2008-03-10 19:26:42 +0000 | [diff] [blame] | 91 | #pragma omp parallel for |
| 92 | for (i = 2; i < n; i++) |
| 93 | { |
| 94 | if (is_prime(pflag, i)) |
| 95 | { |
| 96 | primes[total] = i; |
| 97 | total++; |
| 98 | } |
| 99 | } |
bart | 72ab1ff | 2008-03-12 16:48:07 +0000 | [diff] [blame] | 100 | if (! silent) |
bart | 0aeb186 | 2008-03-10 19:26:42 +0000 | [diff] [blame] | 101 | { |
bart | 72ab1ff | 2008-03-12 16:48:07 +0000 | [diff] [blame] | 102 | printf("Number of prime numbers between 2 and %d: %d\n", |
| 103 | n, total); |
| 104 | for (i = 0; i < total; i++) |
| 105 | { |
| 106 | printf("%d\n", primes[i]); |
| 107 | } |
bart | 0aeb186 | 2008-03-10 19:26:42 +0000 | [diff] [blame] | 108 | } |
| 109 | |
| 110 | free(pflag); |
| 111 | free(primes); |
| 112 | |
| 113 | return 0; |
| 114 | } |