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comparison libtommath/etc/tune.c @ 284:eed26cff980b

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propagate from branch 'au.asn.ucc.matt.ltm.dropbear' (head 6c790cad5a7fa866ad062cb3a0c279f7ba788583) to branch 'au.asn.ucc.matt.dropbear' (head fff0894a0399405a9410ea1c6d118f342cf2aa64)
author Matt Johnston <matt@ucc.asn.au>
date Wed, 08 Mar 2006 13:23:49 +0000
parents
children 5ff8218bcee9
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283:bd240aa12ba7 284:eed26cff980b
1 /* Tune the Karatsuba parameters
2 *
3 * Tom St Denis, [email protected]
4 */
5 #include <tommath.h>
6 #include <time.h>
7
8 /* how many times todo each size mult. Depends on your computer. For slow computers
9 * this can be low like 5 or 10. For fast [re: Athlon] should be 25 - 50 or so
10 */
11 #define TIMES (1UL<<14UL)
12
13 /* RDTSC from Scott Duplichan */
14 static ulong64 TIMFUNC (void)
15 {
16 #if defined __GNUC__
17 #if defined(__i386__) || defined(__x86_64__)
18 unsigned long long a;
19 __asm__ __volatile__ ("rdtsc\nmovl %%eax,%0\nmovl %%edx,4+%0\n"::"m"(a):"%eax","%edx");
20 return a;
21 #else /* gcc-IA64 version */
22 unsigned long result;
23 __asm__ __volatile__("mov %0=ar.itc" : "=r"(result) :: "memory");
24 while (__builtin_expect ((int) result == -1, 0))
25 __asm__ __volatile__("mov %0=ar.itc" : "=r"(result) :: "memory");
26 return result;
27 #endif
28
29 // Microsoft and Intel Windows compilers
30 #elif defined _M_IX86
31 __asm rdtsc
32 #elif defined _M_AMD64
33 return __rdtsc ();
34 #elif defined _M_IA64
35 #if defined __INTEL_COMPILER
36 #include <ia64intrin.h>
37 #endif
38 return __getReg (3116);
39 #else
40 #error need rdtsc function for this build
41 #endif
42 }
43
44
45 #ifndef X86_TIMER
46
47 /* generic ISO C timer */
48 ulong64 LBL_T;
49 void t_start(void) { LBL_T = TIMFUNC(); }
50 ulong64 t_read(void) { return TIMFUNC() - LBL_T; }
51
52 #else
53 extern void t_start(void);
54 extern ulong64 t_read(void);
55 #endif
56
57 ulong64 time_mult(int size, int s)
58 {
59 unsigned long x;
60 mp_int a, b, c;
61 ulong64 t1;
62
63 mp_init (&a);
64 mp_init (&b);
65 mp_init (&c);
66
67 mp_rand (&a, size);
68 mp_rand (&b, size);
69
70 if (s == 1) {
71 KARATSUBA_MUL_CUTOFF = size;
72 } else {
73 KARATSUBA_MUL_CUTOFF = 100000;
74 }
75
76 t_start();
77 for (x = 0; x < TIMES; x++) {
78 mp_mul(&a,&b,&c);
79 }
80 t1 = t_read();
81 mp_clear (&a);
82 mp_clear (&b);
83 mp_clear (&c);
84 return t1;
85 }
86
87 ulong64 time_sqr(int size, int s)
88 {
89 unsigned long x;
90 mp_int a, b;
91 ulong64 t1;
92
93 mp_init (&a);
94 mp_init (&b);
95
96 mp_rand (&a, size);
97
98 if (s == 1) {
99 KARATSUBA_SQR_CUTOFF = size;
100 } else {
101 KARATSUBA_SQR_CUTOFF = 100000;
102 }
103
104 t_start();
105 for (x = 0; x < TIMES; x++) {
106 mp_sqr(&a,&b);
107 }
108 t1 = t_read();
109 mp_clear (&a);
110 mp_clear (&b);
111 return t1;
112 }
113
114 int
115 main (void)
116 {
117 ulong64 t1, t2;
118 int x, y;
119
120 for (x = 8; ; x += 2) {
121 t1 = time_mult(x, 0);
122 t2 = time_mult(x, 1);
123 printf("%d: %9llu %9llu, %9llu\n", x, t1, t2, t2 - t1);
124 if (t2 < t1) break;
125 }
126 y = x;
127
128 for (x = 8; ; x += 2) {
129 t1 = time_sqr(x, 0);
130 t2 = time_sqr(x, 1);
131 printf("%d: %9llu %9llu, %9llu\n", x, t1, t2, t2 - t1);
132 if (t2 < t1) break;
133 }
134 printf("KARATSUBA_MUL_CUTOFF = %d\n", y);
135 printf("KARATSUBA_SQR_CUTOFF = %d\n", x);
136
137 return 0;
138 }