mdw@git.distorted.org.uk Git - mLib/blob - struct/buf-float.c

   1 /* -*-c-*-
   2  *
   3  * Encoding and decoding floating-point values
   4  *
   5  * (c) 2023 Straylight/Edgeware
   6  */
   7
   8 /*----- Licensing notice --------------------------------------------------*
   9  *
  10  * This file is part of the mLib utilities library.
  11  *
  12  * mLib is free software: you can redistribute it and/or modify it under
  13  * the terms of the GNU Library General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or (at
  15  * your option) any later version.
  16  *
  17  * mLib is distributed in the hope that it will be useful, but WITHOUT
  18  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  19  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
  20  * License for more details.
  21  *
  22  * You should have received a copy of the GNU Library General Public
  23  * License along with mLib.  If not, write to the Free Software
  24  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  25  * USA.
  26  */
  27
  28 /*----- Header files ------------------------------------------------------*/
  29
  30 #include <float.h>
  31 #include <math.h>
  32
  33 #include "bits.h"
  34 #include "buf.h"
  35 #include "fltfmt.h"
  36
  37 /*----- External functions ------------------------------------------------*/
  38
  39 /* --- @buf_getf{32,64}{,l,b} --- *
  40  *
  41  * Arguments:   @buf *b@ = a buffer to read from
  42  *              @float *x_out@, @double *x_out@ = where to put the result
  43  *
  44  * Returns:     Zero on success, %$-1$% on failure (and the buffer is
  45  *              broken).
  46  *
  47  * Use:         Get an IEEE Binary32 or Binary64 value from the buffer.
  48  *              Conversion is performed using the `fltfmt' machinery, with
  49  *              the usual round-to-nearest/ties-to-even rounding mode.
  50  */
  51
  52 int buf_getf32(buf *b, float *x_out)
  53 {
  54   const octet *p;
  55
  56   p = buf_get(b, 4); if (!p) return (-1);
  57   fltfmt_f32btoflt(x_out, p, FLTRND_NEAREVEN); return (0);
  58 }
  59
  60 int buf_getf32l(buf *b, float *x_out)
  61 {
  62   const octet *p;
  63
  64   p = buf_get(b, 4); if (!p) return (-1);
  65   fltfmt_f32ltoflt(x_out, p, FLTRND_NEAREVEN); return (0);
  66 }
  67
  68 int buf_getf32b(buf *b, float *x_out)
  69 {
  70   const octet *p;
  71
  72   p = buf_get(b, 4); if (!p) return (-1);
  73   fltfmt_f32ltoflt(x_out, p, FLTRND_NEAREVEN); return (0);
  74 }
  75
  76 int (dbuf_getf32)(dbuf *db, float *x_out)
  77   { return (dbuf_getf32(db, x_out)); }
  78 int (dbuf_getf32l)(dbuf *db, float *x_out)
  79   { return (dbuf_getf32l(db, x_out)); }
  80 int (dbuf_getf32b)(dbuf *db, float *x_out)
  81   { return (dbuf_getf32b(db, x_out)); }
  82
  83 int buf_getf64(buf *b, double *x_out)
  84 {
  85   const octet *p;
  86
  87   p = buf_get(b, 8); if (!p) return (-1);
  88   fltfmt_f64btodbl(x_out, p, FLTRND_NEAREVEN); return (0);
  89 }
  90
  91 int buf_getf64l(buf *b, double *x_out)
  92 {
  93   const octet *p;
  94
  95   p = buf_get(b, 8); if (!p) return (-1);
  96   fltfmt_f64ltodbl(x_out, p, FLTRND_NEAREVEN); return (0);
  97 }
  98
  99 int buf_getf64b(buf *b, double *x_out)
 100 {
 101   const octet *p;
 102
 103   p = buf_get(b, 8); if (!p) return (-1);
 104   fltfmt_f64ltodbl(x_out, p, FLTRND_NEAREVEN); return (0);
 105 }
 106
 107 int (dbuf_getf64)(dbuf *db, double *x_out)
 108   { return (dbuf_getf64(db, x_out)); }
 109 int (dbuf_getf64l)(dbuf *db, double *x_out)
 110   { return (dbuf_getf64l(db, x_out)); }
 111 int (dbuf_getf64b)(dbuf *db, double *x_out)
 112   { return (dbuf_getf64b(db, x_out)); }
 113
 114 /* --- @buf_putf{32,64}{,l,b} --- *
 115  *
 116  * Arguments:   @buf *b@ = a buffer to write to
 117  *              @double x@ = a number to write
 118  *
 119  * Returns:     Zero on success, %$-1$% on failure (and the buffer is
 120  *              broken).
 121  *
 122  * Use:         Get an IEEE Binary32 or Binary64 value from the buffer.
 123  *              Conversion is performed using the `fltfmt' machinery, with
 124  *              the usual round-to-nearest/ties-to-even rounding mode.
 125  */
 126
 127 int buf_putf32(buf *b, float x)
 128 {
 129   octet *p;
 130
 131   p = buf_get(b, 4); if (!p) return (-1);
 132   fltfmt_flttof32b(p, x, FLTRND_NEAREVEN); return (0);
 133 }
 134
 135 int buf_putf32l(buf *b, float x)
 136 {
 137   octet *p;
 138
 139   p = buf_get(b, 4); if (!p) return (-1);
 140   fltfmt_flttof32l(p, x, FLTRND_NEAREVEN); return (0);
 141 }
 142
 143 int buf_putf32b(buf *b, float x)
 144 {
 145   octet *p;
 146
 147   p = buf_get(b, 4); if (!p) return (-1);
 148   fltfmt_flttof32b(p, x, FLTRND_NEAREVEN); return (0);
 149 }
 150
 151 int (dbuf_putf32)(dbuf *db, float x)
 152   { return (dbuf_putf32(db, x)); }
 153 int (dbuf_putf32l)(dbuf *db, float x)
 154   { return (dbuf_putf32l(db, x)); }
 155 int (dbuf_putf32b)(dbuf *db, float x)
 156   { return (dbuf_putf32b(db, x)); }
 157
 158 int buf_putf64(buf *b, double x)
 159 {
 160   octet *p;
 161
 162   p = buf_get(b, 8); if (!p) return (-1);
 163   fltfmt_dbltof64b(p, x, FLTRND_NEAREVEN); return (0);
 164 }
 165
 166 int buf_putf64l(buf *b, double x)
 167 {
 168   octet *p;
 169
 170   p = buf_get(b, 8); if (!p) return (-1);
 171   fltfmt_dbltof64l(p, x, FLTRND_NEAREVEN); return (0);
 172 }
 173
 174 int buf_putf64b(buf *b, double x)
 175 {
 176   octet *p;
 177
 178   p = buf_get(b, 8); if (!p) return (-1);
 179   fltfmt_dbltof64b(p, x, FLTRND_NEAREVEN); return (0);
 180 }
 181
 182 int (dbuf_putf64)(dbuf *db, double x)
 183   { return (dbuf_putf64(db, x)); }
 184 int (dbuf_putf64l)(dbuf *db, double x)
 185   { return (dbuf_putf64l(db, x)); }
 186 int (dbuf_putf64b)(dbuf *db, double x)
 187   { return (dbuf_putf64b(db, x)); }
 188
 189 /*----- That's all, folks -------------------------------------------------*/