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Diffstat (limited to 'contrib/bc/lib/testmul.c')
| -rw-r--r-- | contrib/bc/lib/testmul.c | 244 |
1 files changed, 244 insertions, 0 deletions
diff --git a/contrib/bc/lib/testmul.c b/contrib/bc/lib/testmul.c new file mode 100644 index 000000000000..f7044d67f26e --- /dev/null +++ b/contrib/bc/lib/testmul.c @@ -0,0 +1,244 @@ +/* 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; +} |