amd64/bareMetalOS-0.5.2/baremetal0.5.2/programs/prime.c

   1 // Prime Test Program (v1.2, September 7 2010)
   2 // Written by Ian Seyler
   3 //
   4 // This program checks all odd numbers between 3 and 'maxn' and determines if they are prime.
   5 // On exit the program will display the execution time and how many prime numbers were found.
   6 // Useful for testing runtime performance between Linux and BareMetal OS.
   7 //
   8 // BareMetal compile using GCC (Tested with 4.5.0)
   9 // gcc -c -m64 -nostdlib -nostartfiles -nodefaultlibs -mno-red-zone -o prime.o prime.c -DBAREMETAL
  10 // gcc -c -m64 -nostdlib -nostartfiles -nodefaultlibs -mno-red-zone -o libBareMetal.o libBareMetal.c
  11 // objcopy --remove-section .eh_frame --remove-section .rel.eh_frame --remove-section .rela.eh_frame prime.o
  12 // objcopy --remove-section .eh_frame --remove-section .rel.eh_frame --remove-section .rela.eh_frame libBareMetal.o
  13 // ld -T app.ld -o prime.app prime.o libBareMetal.o
  14 //
  15 // Linux compile using GCC (Tested with 4.5.0)
  16 // gcc -m64 -o prime prime.c -DLINUX
  17 // strip prime
  18 //
  19 // maxn = 500000        primes = 41538
  20 // maxn = 1000000       primes = 78498
  21 // maxn = 5000000       primes = 348513
  22 // maxn = 10000000      primes = 664579
  23
  24
  25 #ifdef LINUX
  26 #include <stdio.h>
  27 #include <time.h>
  28 #endif
  29
  30 #ifdef BAREMETAL
  31 #include "libBareMetal.h"
  32 #endif
  33
  34 int main()
  35 {
  36         // primes is set to 1 since we don't calculate for '2' as it is a known prime number
  37         register unsigned long i, j, maxn=1000000, primes=1;
  38
  39 #ifdef BAREMETAL
  40         unsigned char tstring[25];
  41         unsigned long start, finish;
  42         start = b_get_timercounter();
  43 #endif
  44
  45 #ifdef LINUX
  46         time_t start, finish;
  47         time(&start);
  48 #endif
  49
  50         for(i=3; i<=maxn; i+=2)
  51         {
  52                 for(j=2; j<=i-1; j++)
  53                 {
  54                         if(i%j==0) break; //Number is divisble by some other number. So break out
  55                 }
  56                 if(i==j)
  57                 {
  58                         primes = primes + 1;
  59                 }
  60         } //Continue loop up to max number
  61
  62 #ifdef LINUX
  63         time(&finish);
  64         printf("%u in %.0lf seconds\n", primes, difftime(finish, start));
  65 #endif
  66
  67 #ifdef BAREMETAL
  68         finish = b_get_timercounter();
  69         b_int_to_string(primes, tstring);
  70         b_print_string(tstring);
  71         b_print_string(" in ");
  72         finish = (finish - start) / 8;
  73         b_int_to_string(finish, tstring);
  74         b_print_string(tstring);
  75         b_print_string(" seconds\n");
  76 #endif
  77
  78         return 0;
  79 }
  80
  81 // EOF