Mercurial > dropbear
view etc/tune.c @ 163:8e94663164c6 libtommath LTM_DB_0.44
make pointers volatile so that memory zeroing won't get optimised away
author | Matt Johnston <matt@ucc.asn.au> |
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date | Sun, 02 Jan 2005 17:09:26 +0000 |
parents | d29b64170cf0 |
children | d8254fc979e9 |
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/* Tune the Karatsuba parameters * * Tom St Denis, [email protected] */ #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) #ifndef X86_TIMER /* generic ISO C timer */ ulong64 __T; void t_start(void) { __T = clock(); } ulong64 t_read(void) { return clock() - __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; }