commit files needed for zpm-fetchurl

[zpackage] / tomsfastmath / src / addsub / s_fp_add.c

diff --git a/tomsfastmath/src/addsub/s_fp_add.c b/tomsfastmath/src/addsub/s_fp_add.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>
+
+/* unsigned addition */
+void s_fp_add(fp_int *a, fp_int *b, fp_int *c)
+{
+  int      x, y, oldused;
+  register fp_word  t;
+
+  y       = MAX(a->used, b->used);
+  oldused = MIN(c->used, FP_SIZE);
+  c->used = y;
+ 
+  t = 0;
+  for (x = 0; x < y; x++) {
+      t         += ((fp_word)a->dp[x]) + ((fp_word)b->dp[x]);
+      c->dp[x]   = (fp_digit)t;
+      t        >>= DIGIT_BIT;
+  }
+  if (t != 0 && x < FP_SIZE) {
+     c->dp[c->used++] = (fp_digit)t;
+     ++x;
+  }
+
+  c->used = x;
+  for (; x < oldused; x++) {
+     c->dp[x] = 0;
+  }
+  fp_clamp(c);
+}
+
+/* $Source$ */
+/* $Revision$ */
+/* $Date$ */