| /**************************************************************************** |
| * lib/lib_libdtoa.c |
| * |
| * This file was ported to NuttX by Yolande Cates. |
| * |
| * Copyright (c) 1990, 1993 |
| * The Regents of the University of California. All rights reserved. |
| * |
| * This code is derived from software contributed to Berkeley by |
| * Chris Torek. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * 3. All advertising materials mentioning features or use of this software |
| * must display the following acknowledgement: |
| * This product includes software developed by the University of |
| * California, Berkeley and its contributors. |
| * 4. Neither the name of the University nor the names of its contributors |
| * may be used to endorse or promote products derived from this software |
| * without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| * |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * Included Files |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * Pre-processor Definitions |
| ****************************************************************************/ |
| |
| #define MAXEXP 308 |
| |
| /**************************************************************************** |
| * Private Type Declarations |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * Private Function Prototypes |
| ****************************************************************************/ |
| |
| static char* cvt(double value, int ndigits, int flags, char *sign, |
| int *decpt, int ch, int *length); |
| static int exponent(char *p0, int exp, int fmtch); |
| |
| /**************************************************************************** |
| * Global Constant Data |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * Global Variables |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * Private Constant Data |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * Private Variables |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * Private Functions |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * Name: cvt |
| ****************************************************************************/ |
| |
| static char* cvt(double value, int ndigits, int flags, char *sign, |
| int *decpt, int ch, int *length) |
| { |
| int mode, dsgn; |
| char *digits, *bp, *rve; |
| |
| if (ch == 'f') |
| { |
| mode = 3; /* ndigits after the decimal point */ |
| } |
| else |
| { |
| /* To obtain ndigits after the decimal point for the 'e' and 'E' |
| * formats, round to ndigits + 1 significant figures. |
| */ |
| |
| if (ch == 'e' || ch == 'E') |
| { |
| ndigits++; |
| } |
| mode = 2; /* ndigits significant digits */ |
| } |
| |
| if (value < 0) |
| { |
| value = -value; |
| *sign = '-'; |
| } |
| else |
| { |
| *sign = '\000'; |
| } |
| |
| digits = __dtoa(value, mode, ndigits, decpt, &dsgn, &rve); |
| if ((ch != 'g' && ch != 'G') || IS_ALTFORM(flags)) |
| { |
| /* Print trailing zeros */ |
| |
| bp = digits + ndigits; |
| if (ch == 'f') |
| { |
| if (*digits == '0' && value) |
| { |
| *decpt = -ndigits + 1; |
| } |
| bp += *decpt; |
| } |
| |
| if (value == 0) |
| { |
| /* kludge for __dtoa irregularity */ |
| |
| rve = bp; |
| } |
| |
| while (rve < bp) |
| { |
| *rve++ = '0'; |
| } |
| } |
| |
| *length = rve - digits; |
| return digits; |
| } |
| |
| /**************************************************************************** |
| * Name: exponent |
| ****************************************************************************/ |
| |
| static int exponent(FAR char *p0, int exp, int fmtch) |
| { |
| FAR char *p; |
| FAR char *t; |
| char expbuf[MAXEXP]; |
| |
| p = p0; |
| *p++ = fmtch; |
| if (exp < 0) |
| { |
| exp = -exp; |
| *p++ = '-'; |
| } |
| else |
| { |
| *p++ = '+'; |
| } |
| |
| t = expbuf + MAXEXP; |
| if (exp > 9) |
| { |
| do |
| { |
| *--t = (exp % 10) + '0'; |
| } |
| while ((exp /= 10) > 9); |
| *--t = exp + '0'; |
| for (; t < expbuf + MAXEXP; *p++ = *t++); |
| } |
| else |
| { |
| *p++ = '0'; |
| *p++ = exp + '0'; |
| } |
| return (p - p0); |
| } |
| |
| /**************************************************************************** |
| * Name: lib_dtoa |
| * |
| * Description: |
| * This is part of lib_vsprintf(). It handles the floating point formats. |
| * |
| ****************************************************************************/ |
| |
| static void lib_dtoa(FAR struct lib_outstream_s *obj, int ch, int prec, |
| uint8_t flags, double _double) |
| { |
| FAR char *cp; /* Handy char pointer (short term usage) */ |
| FAR char *cp_free = NULL; /* BIONIC: copy of cp to be freed after usage */ |
| char expstr[7]; /* Buffer for exponent string */ |
| char sign; /* Temporary negative sign for floats */ |
| int expt; /* Integer value of exponent */ |
| int expsize = 0; /* Character count for expstr */ |
| int ndig; /* Actual number of digits returned by cvt */ |
| int size; /* Size of converted field or string */ |
| int i; |
| |
| cp = cvt(_double, prec, flags, &sign, &expt, ch, &ndig); |
| cp_free = cp; |
| |
| if (ch == 'g' || ch == 'G') |
| { |
| /* 'g' or 'G' fmt */ |
| |
| if (expt <= -4 || expt > prec) |
| { |
| ch = (ch == 'g') ? 'e' : 'E'; |
| } |
| else |
| { |
| ch = 'g'; |
| } |
| } |
| |
| if (ch <= 'e') |
| { |
| /* 'e' or 'E' fmt */ |
| |
| --expt; |
| expsize = exponent(expstr, expt, ch); |
| size = expsize + ndig; |
| if (ndig > 1 || IS_ALTFORM(flags)) |
| { |
| ++size; |
| } |
| } |
| else if (ch == 'f') |
| { |
| /* f fmt */ |
| |
| if (expt > 0) |
| { |
| size = expt; |
| if (prec || IS_ALTFORM(flags)) |
| { |
| size += prec + 1; |
| } |
| } |
| else /* "0.X" */ |
| { |
| size = prec + 2; |
| } |
| } |
| else if (expt >= ndig) |
| { |
| /* fixed g fmt */ |
| |
| size = expt; |
| if (IS_ALTFORM(flags)) |
| { |
| ++size; |
| } |
| } |
| else |
| { |
| size = ndig + (expt > 0 ? 1 : 2 - expt); |
| } |
| |
| if (sign) |
| { |
| obj->put(obj, '-'); |
| } |
| |
| if (_double == 0) |
| { |
| /* kludge for __dtoa irregularity */ |
| |
| obj->put(obj, '0'); |
| if (expt < ndig || IS_ALTFORM(flags)) |
| { |
| obj->put(obj, '.'); |
| |
| i = ndig - 1; |
| while (i > 0) |
| { |
| obj->put(obj, '0'); |
| i--; |
| } |
| } |
| } |
| else if (expt <= 0) |
| { |
| obj->put(obj, '0'); |
| obj->put(obj, '.'); |
| |
| i = ndig; |
| while (i > 0) |
| { |
| obj->put(obj, *cp); |
| i--; |
| cp++; |
| } |
| } |
| else if (expt >= ndig) |
| { |
| i = ndig; |
| while (i > 0) |
| { |
| obj->put(obj, *cp); |
| i--; |
| cp++; |
| } |
| |
| i = expt - ndig; |
| while (i > 0) |
| { |
| obj->put(obj, '0'); |
| i--; |
| } |
| |
| if (IS_ALTFORM(flags)) |
| { |
| obj->put(obj, '.'); |
| } |
| } |
| else |
| { |
| /* print the integer */ |
| |
| i = expt; |
| while (i > 0) |
| { |
| obj->put(obj, *cp); |
| i--; |
| cp++; |
| } |
| |
| /* print the decimal place */ |
| |
| obj->put(obj, '.'); |
| |
| /* print the decimal */ |
| |
| i = ndig - expt; |
| while (i > 0) |
| { |
| obj->put(obj, *cp); |
| i--; |
| cp++; |
| } |
| } |
| } |
| |
| /**************************************************************************** |
| * Public Functions |
| ****************************************************************************/ |
| |
