commit files needed for zpm-fetchurl

[zpackage] / tomsfastmath / src / bit / fp_count_bits.c

diff --git a/tomsfastmath/src/bit/fp_count_bits.c b/tomsfastmath/src/bit/fp_count_bits.c
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+/* TomsFastMath, a fast ISO C bignum library.
+ * 
+ * This project is meant to fill in where LibTomMath
+ * falls short.  That is speed ;-)
+ *
+ * This project is public domain and free for all purposes.
+ * 
+ * Tom St Denis, tomstdenis@gmail.com
+ */
+#include <tfm_private.h>
+
+int fp_count_bits (fp_int * a)
+{
+  int     r;
+  fp_digit q;
+
+  /* shortcut */
+  if (a->used == 0) {
+    return 0;
+  }
+
+  /* get number of digits and add that */
+  r = (a->used - 1) * DIGIT_BIT;
+
+  /* take the last digit and count the bits in it */
+  q = a->dp[a->used - 1];
+  while (q > ((fp_digit) 0)) {
+    ++r;
+    q >>= ((fp_digit) 1);
+  }
+  return r;
+}
+
+/* $Source$ */
+/* $Revision$ */
+/* $Date$ */