Diff: math/mul/fp_mul_d.c

Revision:

4:cbaf466d717d

Parent:

0:35aa5be3b78d

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/math/mul/fp_mul_d.c	Tue Jun 10 14:23:09 2014 +0000
@@ -0,0 +1,40 @@
+/* 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.h>
+
+/* c = a * b */
+void fp_mul_d(fp_int *a, fp_digit b, fp_int *c)
+{
+   fp_word  w;
+   int      x, oldused;
+
+   oldused = c->used;
+   c->used = a->used;
+   c->sign = a->sign;
+   w       = 0;
+   for (x = 0; x < a->used; x++) {
+       w         = ((fp_word)a->dp[x]) * ((fp_word)b) + w;
+       c->dp[x]  = (fp_digit)w;
+       w         = w >> DIGIT_BIT;
+   }
+   if (w != 0 && (a->used != FP_SIZE)) {
+      c->dp[c->used++] = w;
+      ++x;
+   }
+   for (; x < oldused; x++) {
+      c->dp[x] = 0;
+   }
+   fp_clamp(c);
+}
+
+
+/* $Source: /cvs/libtom/tomsfastmath/src/mul/fp_mul_d.c,v $ */
+/* $Revision: 1.1 $ */
+/* $Date: 2006/12/31 21:25:53 $ */