x68/fconvert.c

   1 /*
   2  * PROJECT C Library, X68000 PROGRAMMING INTERFACE DEFINITION
   3  * --------------------------------------------------------------------
   4  * This file is written by the Project C Library Group,  and completely
   5  * in public domain. You can freely use, copy, modify, and redistribute
   6  * the whole contents, without this notice.
   7  * --------------------------------------------------------------------
   8  * $Id$
   9  */
  10 /* changed 1997.2.3 by K.Okabe */
  11
  12 /* System headers */
  13 #include <stdlib.h>
  14 #include <sys/xstdlib.h>
  15
  16 /* Functions */
  17 char *fconvert (double x, int ndigit, int *decpt, int *sign, char *buffer)
  18 {
  19     int pos, n;
  20     char *src, *dst;
  21     char string[24];
  22     int figup;
  23
  24     /* 18·å¤ÎÊ¸»úÎó¤ËÊÑ´¹ */
  25     _dtos18 (x, decpt, sign, string);
  26
  27     /* ¥³¥Ô¡¼¸µ¥¢¥É¥ì¥¹¤òÀßÄê */
  28     src = string;
  29
  30     /* ¥³¥Ô¡¼Àè¥¢¥É¥ì¥¹¤òÀßÄê */
  31     dst = buffer;
  32
  33     /* ¾®¿ôÅÀ°ÌÃÖ¤òÆÀ¤ë */
  34     pos = *decpt;
  35
  36     /* ¾®¿ôÅÀ°ÌÃÖ¤¬Éé¤Ê¤é */
  37     if (pos < 0) {
  38
  39         /* Ëä¤á¤ë·å¿ô¤ò·×»» */
  40         n = min (-pos, ndigit);
  41
  42         /* ÀèÆ¬¤ò0¤ÇËä¤á¤ë */
  43         while (n-- > 0)
  44             *dst++ = '0';
  45
  46         /* ¾®¿ôÅÀ°ÌÃÖ¤Ï0¤Ë¤Ê¤ë */
  47         *decpt = 0;
  48
  49     }
  50
  51     /* »Ä¤ê¤Î¥³¥Ô¡¼·å¿ô */
  52     n = ndigit + pos;
  53
  54     /* ³ÊÇ¼Àè¤Ë¥³¥Ô¡¼ */
  55     while (n-- > 0) {
  56
  57         /* Â¤ê¤Ê¤¤ÉôÊ¬¤Ï0¤ÇËä¤á¤ë */
  58         if (*src == '\0') {
  59             while (n-- >= 0)
  60                 *dst++ = '0';
  61             break;
  62         }
  63
  64         /* ÊÑ´¹Ê¸»úÎó¤«¤é¥³¥Ô¡¼ */
  65         *dst++ = *src++;
  66
  67     }
  68
  69     /* ´Ý¤á¤ë */
  70     *decpt += (figup = _round (buffer, dst, *src));
  71
  72     /* ·«¤ê¾å¤¬¤ê¤¬¤¢¤ì¤ÐËöÈø¤Ë0¤òÄÉ²Ã¤¹¤ë */
  73     if (figup)
  74         *dst++ = '0';
  75
  76     /* ½ªÃ¼¤Ë NUL ¤òÂÇ¤Ä */
  77     *dst = '\0';
  78
  79     /* ¥¢¥É¥ì¥¹¤òÊÖ¤¹ */
  80     return buffer;
  81 }