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2 pj 1
/* Project:     OSLib
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 * Description: The OS Construction Kit
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 * Date:                1.6.2000
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 * Idea by:             Luca Abeni & Gerardo Lamastra
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 *
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 * OSLib is an SO project aimed at developing a common, easy-to-use
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 * low-level infrastructure for developing OS kernels and Embedded
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 * Applications; it partially derives from the HARTIK project but it
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 * currently is independently developed.
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 *
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 * OSLib is distributed under GPL License, and some of its code has
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 * been derived from the Linux kernel source; also some important
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 * ideas come from studying the DJGPP go32 extender.
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 *
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 * We acknowledge the Linux Community, Free Software Foundation,
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 * D.J. Delorie and all the other developers who believe in the
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 * freedom of software and ideas.
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 *
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 * For legalese, check out the included GPL license.
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 */
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#include <arch/i386/stdlib.h>
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#include <arch/i386/string.h>
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#include <arch/i386/limits.h>
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#include <arch/i386/float.h>
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#include <ll/i386/mem.h>
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#include <arch/stdarg.h>
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#include <arch/ctype.h>
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#include <arch/math.h>
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#include "sprintf.h"
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FILE(ecvt);
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unsigned ecvt(double v,char *buffer,int width,int prec,int flag)
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{
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    register int len=0;
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    long int exponent,abs_exponent;
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    /* Manage Inf & NaN */
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    if (isspecial(v,buffer)) return(strlen(buffer));
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    /* Check for negative value & add optional + sign */
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    if (v < 0) {
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        *buffer++ = '-';
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        v = -v;
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        len++;
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    } else if (flag & ADD_PLUS) {
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        *buffer++ = '+';
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        len++;
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    }  
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    /* Zero check! */
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    if (v < DBL_MIN) {
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        *buffer++ = '0';
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        *buffer = 0;
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        return(1);
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    }
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    /* Evaluate the exponent */
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    if (v < 1) {
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        exponent = 0;
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        while (v < 1.0) {
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            v *= 10.0;
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            exponent--;
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        }
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    }
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    else {
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        exponent = 0;
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        while (v >= 10.0) {
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            v /= 10.0;
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            exponent++;
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        }
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    }
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    abs_exponent = abs(exponent);
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    if (abs_exponent > 99) width -= 3;
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    else if (abs_exponent > 9) width -= 2;
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    else if (exponent > 0) width -= 1;
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    /* Now the number as IP in range [0,1] */
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    /* Convert this as a fixed point format */
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    len += fcvt(v,buffer,width,prec,flag | RESPECT_WIDTH);
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    /* Now convert the exponent */
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    if (exponent == 0) return(len);
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    buffer += len;
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    *buffer++ = 'e';
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    len += dcvt(exponent,buffer,10,exponent/10+2,ADD_PLUS)+1;
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    return(len);
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}