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;
+}