kc3-lang/libtommath/etc/tune.c

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• Hash : f0b91a57
  Author :
  Date : 2006-04-06T19:49:59
  

  added libtommath-0.39

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• etc/tune.c

• /* Tune the Karatsuba parameters
   *
   * Tom St Denis, tomstdenis@gmail.com
   */
  #include <tommath.h>
  #include <time.h>
  
  /* how many times todo each size mult.  Depends on your computer.  For slow computers
   * this can be low like 5 or 10.  For fast [re: Athlon] should be 25 - 50 or so 
   */
  #define TIMES (1UL<<14UL)
  
  /* RDTSC from Scott Duplichan */
  static ulong64 TIMFUNC (void)
     {
     #if defined __GNUC__
        #if defined(__i386__) || defined(__x86_64__)
           unsigned long long a;
           __asm__ __volatile__ ("rdtsc\nmovl %%eax,%0\nmovl %%edx,4+%0\n"::"m"(a):"%eax","%edx");
           return a;
        #else /* gcc-IA64 version */
           unsigned long result;
           __asm__ __volatile__("mov %0=ar.itc" : "=r"(result) :: "memory");
           while (__builtin_expect ((int) result == -1, 0))
           __asm__ __volatile__("mov %0=ar.itc" : "=r"(result) :: "memory");
           return result;
        #endif
  
     // Microsoft and Intel Windows compilers
     #elif defined _M_IX86
       __asm rdtsc
     #elif defined _M_AMD64
       return __rdtsc ();
     #elif defined _M_IA64
       #if defined __INTEL_COMPILER
         #include <ia64intrin.h>
       #endif
        return __getReg (3116);
     #else
       #error need rdtsc function for this build
     #endif
     }
  
  
  #ifndef X86_TIMER
  
  /* generic ISO C timer */
  ulong64 LBL_T;
  void t_start(void) { LBL_T = TIMFUNC(); }
  ulong64 t_read(void) { return TIMFUNC() - LBL_T; }
  
  #else
  extern void t_start(void);
  extern ulong64 t_read(void);
  #endif
  
  ulong64 time_mult(int size, int s)
  {
    unsigned long     x;
    mp_int  a, b, c;
    ulong64 t1;
  
    mp_init (&a);
    mp_init (&b);
    mp_init (&c);
  
    mp_rand (&a, size);
    mp_rand (&b, size);
  
    if (s == 1) { 
        KARATSUBA_MUL_CUTOFF = size;
    } else {
        KARATSUBA_MUL_CUTOFF = 100000;
    }
  
    t_start();
    for (x = 0; x < TIMES; x++) {
        mp_mul(&a,&b,&c);
    }
    t1 = t_read();
    mp_clear (&a);
    mp_clear (&b);
    mp_clear (&c);
    return t1;
  }
  
  ulong64 time_sqr(int size, int s)
  {
    unsigned long     x;
    mp_int  a, b;
    ulong64 t1;
  
    mp_init (&a);
    mp_init (&b);
  
    mp_rand (&a, size);
  
    if (s == 1) { 
        KARATSUBA_SQR_CUTOFF = size;
    } else {
        KARATSUBA_SQR_CUTOFF = 100000;
    }
  
    t_start();
    for (x = 0; x < TIMES; x++) {
        mp_sqr(&a,&b);
    }
    t1 = t_read();
    mp_clear (&a);
    mp_clear (&b);
    return t1;
  }
  
  int
  main (void)
  {
    ulong64 t1, t2;
    int x, y;
  
    for (x = 8; ; x += 2) { 
       t1 = time_mult(x, 0);
       t2 = time_mult(x, 1);
       printf("%d: %9llu %9llu, %9llu\n", x, t1, t2, t2 - t1);
       if (t2 < t1) break;
    }
    y = x;
  
    for (x = 8; ; x += 2) { 
       t1 = time_sqr(x, 0);
       t2 = time_sqr(x, 1);
       printf("%d: %9llu %9llu, %9llu\n", x, t1, t2, t2 - t1);
       if (t2 < t1) break;
    }
    printf("KARATSUBA_MUL_CUTOFF = %d\n", y);
    printf("KARATSUBA_SQR_CUTOFF = %d\n", x);
  
    return 0;
  }
  
  /* $Source$ */
  /* $Revision$ */
  /* $Date$ */
  

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