121 lines
1.8 KiB
C
121 lines
1.8 KiB
C
/* $NetBSD: dofptoa.c,v 1.2 2003/12/04 16:23:36 drochner Exp $ */
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/*
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* dofptoa - do the grunge work to convert an fp number to ascii
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*/
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#include <stdio.h>
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#include "ntp_fp.h"
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#include "lib_strbuf.h"
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#include "ntp_string.h"
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#include "ntp_stdlib.h"
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char *
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dofptoa(
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u_fp fpv,
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int neg,
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short ndec,
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int msec
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)
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{
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register u_char *cp, *cpend;
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register u_long val;
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register short dec;
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u_char cbuf[12];
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u_char *cpdec;
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char *buf;
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char *bp;
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/*
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* Get a string buffer before starting
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*/
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LIB_GETBUF(buf);
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/*
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* Zero out the buffer
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*/
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memset((char *)cbuf, 0, sizeof cbuf);
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/*
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* Set the pointers to point at the first
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* decimal place. Get a local copy of the value.
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*/
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cp = cpend = &cbuf[5];
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val = fpv;
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/*
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* If we have to, decode the integral part
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*/
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if (!(val & 0xffff0000))
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cp--;
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else {
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register u_short sv = (u_short)(val >> 16);
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register u_short tmp;
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register u_short ten = 10;
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do {
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tmp = sv;
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sv = (u_short) (sv/ten);
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*(--cp) = (u_char)(tmp - ((sv<<3) + (sv<<1)));
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} while (sv != 0);
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}
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/*
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* Figure out how much of the fraction to do
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*/
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if (msec) {
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dec = (short)(ndec + 3);
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if (dec < 3)
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dec = 3;
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cpdec = &cbuf[8];
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} else {
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dec = ndec;
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cpdec = cpend;
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}
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if (dec > 6)
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dec = 6;
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if (dec > 0) {
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do {
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val &= 0xffff;
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val = (val << 3) + (val << 1);
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*cpend++ = (u_char)(val >> 16);
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} while (--dec > 0);
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}
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if (val & 0x8000) {
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register u_char *tp;
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/*
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* Round it. Ick.
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*/
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tp = cpend;
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*(--tp) += 1;
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while (*tp >= 10) {
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*tp = 0;
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*(--tp) += 1;
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}
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}
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/*
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* Remove leading zeroes if necessary
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*/
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while (cp < (cpdec -1) && *cp == 0)
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cp++;
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/*
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* Copy it into the buffer, asciizing as we go.
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*/
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bp = buf;
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if (neg)
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*bp++ = '-';
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while (cp < cpend) {
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if (cp == cpdec)
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*bp++ = '.';
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*bp++ = (char)(*cp++ + '0');
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}
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*bp = '\0';
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return buf;
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}
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