Import code from previous AssetBuilder version

thirdparty/libtommath/bn_mp_mul_d.c

@@ -0,0 +1,75 @@
+#include "tommath_private.h"
+#ifdef BN_MP_MUL_D_C
+/* LibTomMath, multiple-precision integer library -- Tom St Denis
+ *
+ * LibTomMath is a library that provides multiple-precision
+ * integer arithmetic as well as number theoretic functionality.
+ *
+ * The library was designed directly after the MPI library by
+ * Michael Fromberger but has been written from scratch with
+ * additional optimizations in place.
+ *
+ * SPDX-License-Identifier: Unlicense
+ */
+
+/* multiply by a digit */
+int mp_mul_d(const mp_int *a, mp_digit b, mp_int *c)
+{
+   mp_digit u, *tmpa, *tmpc;
+   mp_word  r;
+   int      ix, res, olduse;
+
+   /* make sure c is big enough to hold a*b */
+   if (c->alloc < (a->used + 1)) {
+      if ((res = mp_grow(c, a->used + 1)) != MP_OKAY) {
+         return res;
+      }
+   }
+
+   /* get the original destinations used count */
+   olduse = c->used;
+
+   /* set the sign */
+   c->sign = a->sign;
+
+   /* alias for a->dp [source] */
+   tmpa = a->dp;
+
+   /* alias for c->dp [dest] */
+   tmpc = c->dp;
+
+   /* zero carry */
+   u = 0;
+
+   /* compute columns */
+   for (ix = 0; ix < a->used; ix++) {
+      /* compute product and carry sum for this term */
+      r       = (mp_word)u + ((mp_word)*tmpa++ * (mp_word)b);
+
+      /* mask off higher bits to get a single digit */
+      *tmpc++ = (mp_digit)(r & (mp_word)MP_MASK);
+
+      /* send carry into next iteration */
+      u       = (mp_digit)(r >> (mp_word)DIGIT_BIT);
+   }
+
+   /* store final carry [if any] and increment ix offset  */
+   *tmpc++ = u;
+   ++ix;
+
+   /* now zero digits above the top */
+   while (ix++ < olduse) {
+      *tmpc++ = 0;
+   }
+
+   /* set used count */
+   c->used = a->used + 1;
+   mp_clamp(c);
+
+   return MP_OKAY;
+}
+#endif
+
+/* ref:         HEAD -> master, tag: v1.1.0 */
+/* git commit:  08549ad6bc8b0cede0b357a9c341c5c6473a9c55 */
+/* commit time: 2019-01-28 20:32:32 +0100 */