Fix a bug about the iSCSI DHCP dependency issue.

[mirror_edk2.git] / StdLib / LibC / gdtoa / sum.c

/* $NetBSD: sum.c,v 1.1.1.1.14.1 2008/04/08 21:10:55 jdc Exp $ */\r
\r
/****************************************************************\r
\r
The author of this software is David M. Gay.\r
\r
Copyright (C) 1998 by Lucent Technologies\r
All Rights Reserved\r
\r
Permission to use, copy, modify, and distribute this software and\r
its documentation for any purpose and without fee is hereby\r
granted, provided that the above copyright notice appear in all\r
copies and that both that the copyright notice and this\r
permission notice and warranty disclaimer appear in supporting\r
documentation, and that the name of Lucent or any of its entities\r
not be used in advertising or publicity pertaining to\r
distribution of the software without specific, written prior\r
permission.\r
\r
LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,\r
INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.\r
IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY\r
SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES\r
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER\r
IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,\r
ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF\r
THIS SOFTWARE.\r
\r
****************************************************************/\r
\r
/* Please send bug reports to David M. Gay (dmg at acm dot org,\r
 * with " at " changed at "@" and " dot " changed to ".").  */\r
#include  <LibConfig.h>\r
\r
#include "gdtoaimp.h"\r
\r
 Bigint *\r
#ifdef KR_headers\r
sum(a, b) Bigint *a; Bigint *b;\r
#else\r
sum(Bigint *a, Bigint *b)\r
#endif\r
{\r
  Bigint *c;\r
  ULong carry, *xc, *xa, *xb, *xe, y;\r
#ifdef Pack_32\r
  ULong z;\r
#endif\r
\r
  if (a->wds < b->wds) {\r
    c = b; b = a; a = c;\r
    }\r
  c = Balloc(a->k);\r
  if (c == NULL)\r
    return NULL;\r
  c->wds = a->wds;\r
  carry = 0;\r
  xa = a->x;\r
  xb = b->x;\r
  xc = c->x;\r
  xe = xc + b->wds;\r
#ifdef Pack_32\r
  do {\r
    y = (*xa & 0xffff) + (*xb & 0xffff) + carry;\r
    carry = (y & 0x10000) >> 16;\r
    z = (*xa++ >> 16) + (*xb++ >> 16) + carry;\r
    carry = (z & 0x10000) >> 16;\r
    Storeinc(xc, z, y);\r
    }\r
    while(xc < xe);\r
  xe += a->wds - b->wds;\r
  while(xc < xe) {\r
    y = (*xa & 0xffff) + carry;\r
    carry = (y & 0x10000) >> 16;\r
    z = (*xa++ >> 16) + carry;\r
    carry = (z & 0x10000) >> 16;\r
    Storeinc(xc, z, y);\r
    }\r
#else\r
  do {\r
    y = *xa++ + *xb++ + carry;\r
    carry = (y & 0x10000) >> 16;\r
    *xc++ = y & 0xffff;\r
    }\r
    while(xc < xe);\r
  xe += a->wds - b->wds;\r
  while(xc < xe) {\r
    y = *xa++ + carry;\r
    carry = (y & 0x10000) >> 16;\r
    *xc++ = y & 0xffff;\r
    }\r
#endif\r
  if (carry) {\r
    if (c->wds == c->maxwds) {\r
      b = Balloc(c->k + 1);\r
      if (b == NULL)\r
        return NULL;\r
      Bcopy(b, c);\r
      Bfree(c);\r
      c = b;\r
      }\r
    c->x[c->wds++] = 1;\r
    }\r
  return c;\r
  }\r