diff options
Diffstat (limited to 'libtommath/etc/tune.c')
-rw-r--r-- | libtommath/etc/tune.c | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/libtommath/etc/tune.c b/libtommath/etc/tune.c new file mode 100644 index 0000000..acb146f --- /dev/null +++ b/libtommath/etc/tune.c @@ -0,0 +1,138 @@ +/* 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; +} |