The Tor Browser: security/nss/lib/freebl/mpi/mulsqr.c@b8a032363ba2

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

     1 /*

     2  * Test whether to include squaring code given the current settings

     3  *

     4  * This Source Code Form is subject to the terms of the Mozilla Public

     5  * License, v. 2.0. If a copy of the MPL was not distributed with this

     6  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     8 #include <stdio.h>

     9 #include <stdlib.h>

    10 #include <limits.h>

    11 #include <time.h>

    13 #define MP_SQUARE 1  /* make sure squaring code is included */

    15 #include "mpi.h"

    16 #include "mpprime.h"

    18 int main(int argc, char *argv[])

    19 {

    20   int           ntests, prec, ix;

    21   unsigned int  seed;

    22   clock_t       start, stop;

    23   double        multime, sqrtime;

    24   mp_int        a, c;

    26   seed = (unsigned int)time(NULL);

    28   if(argc < 3) {

    29     fprintf(stderr, "Usage: %s <ntests> <nbits>\n", argv[0]);

    30     return 1;

    31   }

    33   if((ntests = abs(atoi(argv[1]))) == 0) {

    34     fprintf(stderr, "%s: must request at least 1 test.\n", argv[0]);

    35     return 1;

    36   }

    37   if((prec = abs(atoi(argv[2]))) < CHAR_BIT) {

    38     fprintf(stderr, "%s: must request at least %d bits.\n", argv[0],

    39 	    CHAR_BIT);

    40     return 1;

    41   }

    43   prec = (prec + (DIGIT_BIT - 1)) / DIGIT_BIT;

    45   mp_init_size(&a, prec);

    46   mp_init_size(&c, 2 * prec);

    48   /* Test multiplication by self */

    49   srand(seed);

    50   start = clock();

    51   for(ix = 0; ix < ntests; ix++) {

    52     mpp_random_size(&a, prec);

    53     mp_mul(&a, &a, &c);

    54   }

    55   stop = clock();

    57   multime = (double)(stop - start) / CLOCKS_PER_SEC;

    59   /* Test squaring */

    60   srand(seed);

    61   start = clock();

    62   for(ix = 0; ix < ntests; ix++) {

    63     mpp_random_size(&a, prec);

    64     mp_sqr(&a, &c);

    65   }

    66   stop = clock();

    68   sqrtime = (double)(stop - start) / CLOCKS_PER_SEC;

    70   printf("Multiply: %.4f\n", multime);

    71   printf("Square:   %.4f\n", sqrtime);

    72   if(multime < sqrtime) {

    73     printf("Speedup:  %.1f%%\n", 100.0 * (1.0 - multime / sqrtime));

    74     printf("Prefer:   multiply\n");

    75   } else {

    76     printf("Speedup:  %.1f%%\n", 100.0 * (1.0 - sqrtime / multime));

    77     printf("Prefer:   square\n");

    78   }

    80   mp_clear(&a); mp_clear(&c);

    81   return 0;

    83 }

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