soft-fp/soft-fp.h

   1 /* Software floating-point emulation.
   2    Copyright (C) 1997-2013 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Richard Henderson (rth@cygnus.com),
   5                   Jakub Jelinek (jj@ultra.linux.cz),
   6                   David S. Miller (davem@redhat.com) and
   7                   Peter Maydell (pmaydell@chiark.greenend.org.uk).
   8
   9    The GNU C Library is free software; you can redistribute it and/or
  10    modify it under the terms of the GNU Lesser General Public
  11    License as published by the Free Software Foundation; either
  12    version 2.1 of the License, or (at your option) any later version.
  13
  14    In addition to the permissions in the GNU Lesser General Public
  15    License, the Free Software Foundation gives you unlimited
  16    permission to link the compiled version of this file into
  17    combinations with other programs, and to distribute those
  18    combinations without any restriction coming from the use of this
  19    file.  (The Lesser General Public License restrictions do apply in
  20    other respects; for example, they cover modification of the file,
  21    and distribution when not linked into a combine executable.)
  22
  23    The GNU C Library is distributed in the hope that it will be useful,
  24    but WITHOUT ANY WARRANTY; without even the implied warranty of
  25    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  26    Lesser General Public License for more details.
  27
  28    You should have received a copy of the GNU Lesser General Public
  29    License along with the GNU C Library; if not, see
  30    <http://www.gnu.org/licenses/>.  */
  31
  32 #ifndef SOFT_FP_H
  33 #define SOFT_FP_H
  34
  35 #ifdef _LIBC
  36 #include <sfp-machine.h>
  37 #else
  38 #include "sfp-machine.h"
  39 #endif
  40
  41 /* Allow sfp-machine to have its own byte order definitions. */
  42 #ifndef __BYTE_ORDER
  43 #ifdef _LIBC
  44 #include <endian.h>
  45 #else
  46 #error "endianness not defined by sfp-machine.h"
  47 #endif
  48 #endif
  49
  50 #define _FP_WORKBITS            3
  51 #define _FP_WORK_LSB            ((_FP_W_TYPE)1 << 3)
  52 #define _FP_WORK_ROUND          ((_FP_W_TYPE)1 << 2)
  53 #define _FP_WORK_GUARD          ((_FP_W_TYPE)1 << 1)
  54 #define _FP_WORK_STICKY         ((_FP_W_TYPE)1 << 0)
  55
  56 #ifndef FP_RND_NEAREST
  57 # define FP_RND_NEAREST         0
  58 # define FP_RND_ZERO            1
  59 # define FP_RND_PINF            2
  60 # define FP_RND_MINF            3
  61 #endif
  62 #ifndef FP_ROUNDMODE
  63 # define FP_ROUNDMODE           FP_RND_NEAREST
  64 #endif
  65
  66 /* By default don't care about exceptions. */
  67 #ifndef FP_EX_INVALID
  68 #define FP_EX_INVALID           0
  69 #endif
  70 #ifndef FP_EX_OVERFLOW
  71 #define FP_EX_OVERFLOW          0
  72 #endif
  73 #ifndef FP_EX_UNDERFLOW
  74 #define FP_EX_UNDERFLOW         0
  75 #endif
  76 #ifndef FP_EX_DIVZERO
  77 #define FP_EX_DIVZERO           0
  78 #endif
  79 #ifndef FP_EX_INEXACT
  80 #define FP_EX_INEXACT           0
  81 #endif
  82 #ifndef FP_EX_DENORM
  83 #define FP_EX_DENORM            0
  84 #endif
  85
  86 /* _FP_STRUCT_LAYOUT may be defined as an attribute to determine the
  87    struct layout variant used for structures where bit-fields are used
  88    to access specific parts of binary floating-point numbers.  This is
  89    required for systems where the default ABI uses struct layout with
  90    differences in how consecutive bit-fields are laid out from the
  91    default expected by soft-fp.  */
  92 #ifndef _FP_STRUCT_LAYOUT
  93 #define _FP_STRUCT_LAYOUT
  94 #endif
  95
  96 #ifdef _FP_DECL_EX
  97 #define FP_DECL_EX                                      \
  98   int _fex = 0;                                         \
  99   _FP_DECL_EX
 100 #else
 101 #define FP_DECL_EX int _fex = 0
 102 #endif
 103
 104 /* Initialize any machine-specific state used in FP_ROUNDMODE,
 105    FP_TRAPPING_EXCEPTIONS or FP_HANDLE_EXCEPTIONS.  */
 106 #ifndef FP_INIT_ROUNDMODE
 107 #define FP_INIT_ROUNDMODE do {} while (0)
 108 #endif
 109
 110 /* Initialize any machine-specific state used in
 111    FP_HANDLE_EXCEPTIONS.  */
 112 #ifndef FP_INIT_EXCEPTIONS
 113 #define FP_INIT_EXCEPTIONS FP_INIT_ROUNDMODE
 114 #endif
 115
 116 #ifndef FP_HANDLE_EXCEPTIONS
 117 #define FP_HANDLE_EXCEPTIONS do {} while (0)
 118 #endif
 119
 120 #ifndef FP_INHIBIT_RESULTS
 121 /* By default we write the results always.
 122  * sfp-machine may override this and e.g.
 123  * check if some exceptions are unmasked
 124  * and inhibit it in such a case.
 125  */
 126 #define FP_INHIBIT_RESULTS 0
 127 #endif
 128
 129 #define FP_SET_EXCEPTION(ex)                            \
 130   _fex |= (ex)
 131
 132 #define FP_UNSET_EXCEPTION(ex)                          \
 133   _fex &= ~(ex)
 134
 135 #define FP_CLEAR_EXCEPTIONS                             \
 136   _fex = 0
 137
 138 #define FP_CUR_EXCEPTIONS                               \
 139   (_fex)
 140
 141 #ifndef FP_TRAPPING_EXCEPTIONS
 142 #define FP_TRAPPING_EXCEPTIONS 0
 143 #endif
 144
 145 /* A file using soft-fp may define FP_NO_EXCEPTIONS before including
 146    soft-fp.h to indicate that, although a macro used there could raise
 147    exceptions, or do rounding and potentially thereby raise
 148    exceptions, for some arguments, for the particular arguments used
 149    in that file no exceptions or rounding can occur.  Such a file
 150    should not itself use macros relating to handling exceptions and
 151    rounding modes; this is only for indirect uses (in particular, in
 152    _FP_FROM_INT and the macros it calls).  */
 153 #ifdef FP_NO_EXCEPTIONS
 154
 155 #undef FP_SET_EXCEPTION
 156 #define FP_SET_EXCEPTION(ex) do {} while (0)
 157
 158 #undef FP_CUR_EXCEPTIONS
 159 #define FP_CUR_EXCEPTIONS 0
 160
 161 #undef FP_TRAPPING_EXCEPTIONS
 162 #define FP_TRAPPING_EXCEPTIONS 0
 163
 164 #undef FP_ROUNDMODE
 165 #define FP_ROUNDMODE FP_RND_ZERO
 166
 167 #endif
 168
 169 #define _FP_ROUND_NEAREST(wc, X)                        \
 170 do {                                                    \
 171     if ((_FP_FRAC_LOW_##wc(X) & 15) != _FP_WORK_ROUND)  \
 172       _FP_FRAC_ADDI_##wc(X, _FP_WORK_ROUND);            \
 173 } while (0)
 174
 175 #define _FP_ROUND_ZERO(wc, X)           (void)0
 176
 177 #define _FP_ROUND_PINF(wc, X)                           \
 178 do {                                                    \
 179     if (!X##_s && (_FP_FRAC_LOW_##wc(X) & 7))           \
 180       _FP_FRAC_ADDI_##wc(X, _FP_WORK_LSB);              \
 181 } while (0)
 182
 183 #define _FP_ROUND_MINF(wc, X)                           \
 184 do {                                                    \
 185     if (X##_s && (_FP_FRAC_LOW_##wc(X) & 7))            \
 186       _FP_FRAC_ADDI_##wc(X, _FP_WORK_LSB);              \
 187 } while (0)
 188
 189 #define _FP_ROUND(wc, X)                        \
 190 do {                                            \
 191         if (_FP_FRAC_LOW_##wc(X) & 7)           \
 192           {                                     \
 193             FP_SET_EXCEPTION(FP_EX_INEXACT);    \
 194             switch (FP_ROUNDMODE)               \
 195               {                                 \
 196               case FP_RND_NEAREST:              \
 197                 _FP_ROUND_NEAREST(wc,X);        \
 198                 break;                          \
 199               case FP_RND_ZERO:                 \
 200                 _FP_ROUND_ZERO(wc,X);           \
 201                 break;                          \
 202               case FP_RND_PINF:                 \
 203                 _FP_ROUND_PINF(wc,X);           \
 204                 break;                          \
 205               case FP_RND_MINF:                 \
 206                 _FP_ROUND_MINF(wc,X);           \
 207                 break;                          \
 208               }                                 \
 209           }                                     \
 210 } while (0)
 211
 212 #define FP_CLS_NORMAL           0
 213 #define FP_CLS_ZERO             1
 214 #define FP_CLS_INF              2
 215 #define FP_CLS_NAN              3
 216
 217 #define _FP_CLS_COMBINE(x,y)    (((x) << 2) | (y))
 218
 219 #include "op-1.h"
 220 #include "op-2.h"
 221 #include "op-4.h"
 222 #include "op-8.h"
 223 #include "op-common.h"
 224
 225 /* Sigh.  Silly things longlong.h needs.  */
 226 #define UWtype          _FP_W_TYPE
 227 #define W_TYPE_SIZE     _FP_W_TYPE_SIZE
 228
 229 typedef int QItype __attribute__((mode(QI)));
 230 typedef int SItype __attribute__((mode(SI)));
 231 typedef int DItype __attribute__((mode(DI)));
 232 typedef unsigned int UQItype __attribute__((mode(QI)));
 233 typedef unsigned int USItype __attribute__((mode(SI)));
 234 typedef unsigned int UDItype __attribute__((mode(DI)));
 235 #if _FP_W_TYPE_SIZE == 32
 236 typedef unsigned int UHWtype __attribute__((mode(HI)));
 237 #elif _FP_W_TYPE_SIZE == 64
 238 typedef USItype UHWtype;
 239 #endif
 240
 241 #ifndef CMPtype
 242 #define CMPtype         int
 243 #endif
 244
 245 #define SI_BITS         (__CHAR_BIT__ * (int)sizeof(SItype))
 246 #define DI_BITS         (__CHAR_BIT__ * (int)sizeof(DItype))
 247
 248 #ifndef umul_ppmm
 249 #ifdef _LIBC
 250 #include <stdlib/longlong.h>
 251 #else
 252 #include "longlong.h"
 253 #endif
 254 #endif
 255
 256 #ifdef _LIBC
 257 #include <stdlib.h>
 258 #else
 259 extern void abort (void);
 260 #endif
 261
 262 #endif