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-rw-r--r--libtommath/etc/tune.c138
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;
+}