NetBSD/gnu/dist/bc/lib/testmul.c

245 lines
4.5 KiB
C

/* compute the crossover for recursive and simple multiplication */
#include <stdio.h>
#include <time.h>
#include "number.h"
#ifndef VARARGS
#include <stdarg.h>
#else
#include <varargs.h>
#endif
/* from number.c ... */
extern int mul_base_digits;
/* extern int mul_small_digits; */
extern bc_num _one_;
/* global variables */
int test_n = 1000;
int test_time = 30 * CLOCKS_PER_SEC; /* 30 seconds */
/* Other things for number.c. */
int std_only;
void
out_of_memory()
{
fprintf (stderr, "Fatal error: Out of memory for malloc.\n");
exit (1);
}
/* Runtime error will print a message and stop the machine. */
#ifndef VARARGS
#ifdef __STDC__
void
rt_error (char *mesg, ...)
#else
void
rt_error (mesg)
char *mesg;
#endif
#else
void
rt_error (mesg, va_alist)
char *mesg;
#endif
{
va_list args;
char error_mesg [255];
#ifndef VARARGS
va_start (args, mesg);
#else
va_start (args);
#endif
vsprintf (error_mesg, mesg, args);
va_end (args);
fprintf (stderr, "Runtime error: %s\n", error_mesg);
}
/* A runtime warning tells of some action taken by the processor that
may change the program execution but was not enough of a problem
to stop the execution. */
#ifndef VARARGS
#ifdef __STDC__
void
rt_warn (char *mesg, ...)
#else
void
rt_warn (mesg)
char *mesg;
#endif
#else
void
rt_warn (mesg, va_alist)
char *mesg;
#endif
{
va_list args;
char error_mesg [255];
#ifndef VARARGS
va_start (args, mesg);
#else
va_start (args);
#endif
vsprintf (error_mesg, mesg, args);
va_end (args);
fprintf (stderr, "Runtime warning: %s\n", error_mesg);
}
void
out_char (int ch)
{
putchar (ch);
}
/* Time stuff !!! */
int
timeit ( bc_num a, bc_num b, int *n)
{
clock_t first;
int i, res;
bc_num c;
bc_init_num (&c);
first = clock();
*n = 0;
do {
for (i=0; i<test_n; i++)
bc_multiply(a,b,&c,0);
*n += test_n;
res = (int) (clock() - first);
} while (res < test_time);
return res;
}
int debug = 0; /* Print debugging messages? */
int main (int argc, char **argv)
{
bc_num ten, num, expo, big;
int min, max, mid;
#if 0
int smallsize;
#endif
int n1, n2;
clock_t t1, t2;
float permul1, permul2;
/* args? */
if (argc > 1)
if (strcmp (argv[1], "-d") == 0)
debug = 1;
bc_init_numbers();
bc_init_num (&ten);
bc_init_num (&num);
bc_init_num (&expo);
bc_init_num (&big);
bc_int2num (&ten, 10);
if (debug)
fprintf (stderr, "Timings are for %d multiplies\n"
"Minimum time is %d seconds\n", test_n,
test_time/CLOCKS_PER_SEC);
/* Two of the same size */
min = 10;
max = 500;
if (debug)
fprintf (stderr, "Testing numbers of the same length.\n");
while (min < max) {
mid = (min+max)/2;
if (debug) fprintf (stderr,"Checking %d...\n", mid);
bc_int2num (&expo, mid);
bc_raise (ten, expo, &num, 0);
bc_sub (num, _one_, &num, 0);
mul_base_digits = 2*mid+1;
t1 = timeit (num, num, &n1);
permul1 = (float)t1/(float)n1;
mul_base_digits = 2*mid-1;
t2 = timeit (num, num, &n2);
permul2 = (float)t2/(float)n2;
if (permul1 < permul2)
min = mid+1;
else
max = mid-1;
if (debug) {
fprintf (stderr, "n1 = %d :: n2 = %d\n", n1, n2);
fprintf (stderr, "p1 = %f :: p2 = %f\n", permul1, permul2);
}
}
if (debug)
fprintf (stderr, "Base digits crossover at %d digits\n", min);
printf ("#define MUL_BASE_DIGITS %d\n", 2*min);
#if 0
mul_base_digits = min;
/* Small one times a big one. */
smallsize = min/2;
bc_int2num (&expo, smallsize);
bc_raise (ten, expo, &big, 0);
bc_sub (num, _one_, &big, 0);
min = min / 2;
max = 500;
if (debug)
fprintf (stderr, "Testing numbers of the different length.\n");
while (min < max) {
mid = (min+max)/2;
if (debug) fprintf (stderr, "Checking %d...\n", mid);
bc_int2num (&expo, mid-smallsize);
bc_raise (ten, expo, &num, 0);
bc_sub (num, _one_, &num, 0);
mul_small_digits = mid+1;
t1 = timeit (big, num, &n1);
permul1 = (float)t1/(float)n1;
mul_small_digits = mid-1;
t2 = timeit (big, num, &n2);
permul2 = (float)t2/(float)n2;
if (permul1 < permul2)
min = mid+1;
else
max = mid-1;
if (debug) {
fprintf (stderr, "n1 = %d :: n2 = %d\n", n1, n2);
fprintf (stderr, "p1 = %f :: p2 = %f\n", permul1, permul2);
}
}
if (debug)
fprintf (stderr, "Non equal digits crossover at %d total digits\n", min);
printf ("#define MUL_SMALL_DIGITS = %d\n", min);
#endif
return 0;
}