gdb/dfp.c

   1 /* Decimal floating point support for GDB.
   2
   3    Copyright 2007, 2008 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21
  22 /* The order of the following headers is important for making sure
  23    decNumber structure is large enough to hold decimal128 digits.  */
  24
  25 #include "dpd/decimal128.h"
  26 #include "dpd/decimal64.h"
  27 #include "dpd/decimal32.h"
  28
  29 /* In GDB, we are using an array of gdb_byte to represent decimal values.
  30    They are stored in host byte order.  This routine does the conversion if
  31    the target byte order is different.  */
  32 static void
  33 match_endianness (const gdb_byte *from, int len, gdb_byte *to)
  34 {
  35   int i;
  36
  37 #if WORDS_BIGENDIAN
  38 #define OPPOSITE_BYTE_ORDER BFD_ENDIAN_LITTLE
  39 #else
  40 #define OPPOSITE_BYTE_ORDER BFD_ENDIAN_BIG
  41 #endif
  42
  43   if (gdbarch_byte_order (current_gdbarch) == OPPOSITE_BYTE_ORDER)
  44     for (i = 0; i < len; i++)
  45       to[i] = from[len - i - 1];
  46   else
  47     for (i = 0; i < len; i++)
  48       to[i] = from[i];
  49
  50   return;
  51 }
  52
  53 /* Convert decimal type to its string representation.  LEN is the length
  54    of the decimal type, 4 bytes for decimal32, 8 bytes for decimal64 and
  55    16 bytes for decimal128.  */
  56 void
  57 decimal_to_string (const gdb_byte *decbytes, int len, char *s)
  58 {
  59   gdb_byte dec[16];
  60
  61   match_endianness (decbytes, len, dec);
  62   switch (len)
  63     {
  64       case 4:
  65         decimal32ToString ((decimal32 *) dec, s);
  66         break;
  67       case 8:
  68         decimal64ToString ((decimal64 *) dec, s);
  69         break;
  70       case 16:
  71         decimal128ToString ((decimal128 *) dec, s);
  72         break;
  73       default:
  74         error (_("Unknown decimal floating point type."));
  75         break;
  76     }
  77 }
  78
  79 /* Convert the string form of a decimal value to its decimal representation.
  80    LEN is the length of the decimal type, 4 bytes for decimal32, 8 bytes for
  81    decimal64 and 16 bytes for decimal128.  */
  82 int
  83 decimal_from_string (gdb_byte *decbytes, int len, const char *string)
  84 {
  85   decContext set;
  86   gdb_byte dec[16];
  87
  88   switch (len)
  89     {
  90       case 4:
  91         decContextDefault (&set, DEC_INIT_DECIMAL32);
  92         set.traps = 0;
  93         decimal32FromString ((decimal32 *) dec, string, &set);
  94         break;
  95       case 8:
  96         decContextDefault (&set, DEC_INIT_DECIMAL64);
  97         set.traps = 0;
  98         decimal64FromString ((decimal64 *) dec, string, &set);
  99         break;
 100       case 16:
 101         decContextDefault (&set, DEC_INIT_DECIMAL128);
 102         set.traps = 0;
 103         decimal128FromString ((decimal128 *) dec, string, &set);
 104         break;
 105       default:
 106         error (_("Unknown decimal floating point type."));
 107         break;
 108     }
 109
 110   match_endianness (dec, len, decbytes);
 111
 112   return 1;
 113 }