soft-fp/soft-fp.h

   1 /* Software floating-point emulation.
   2    Copyright (C) 1997-2014 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 /* Sub-exceptions of "invalid".  */
  87 /* Signaling NaN operand.  */
  88 #ifndef FP_EX_INVALID_SNAN
  89 # define FP_EX_INVALID_SNAN     0
  90 #endif
  91 /* Inf * 0.  */
  92 #ifndef FP_EX_INVALID_IMZ
  93 # define FP_EX_INVALID_IMZ      0
  94 #endif
  95 /* fma (Inf, 0, c).  */
  96 #ifndef FP_EX_INVALID_IMZ_FMA
  97 # define FP_EX_INVALID_IMZ_FMA  0
  98 #endif
  99 /* Inf - Inf.  */
 100 #ifndef FP_EX_INVALID_ISI
 101 # define FP_EX_INVALID_ISI      0
 102 #endif
 103 /* 0 / 0.  */
 104 #ifndef FP_EX_INVALID_ZDZ
 105 # define FP_EX_INVALID_ZDZ      0
 106 #endif
 107 /* Inf / Inf.  */
 108 #ifndef FP_EX_INVALID_IDI
 109 # define FP_EX_INVALID_IDI      0
 110 #endif
 111 /* sqrt (negative).  */
 112 #ifndef FP_EX_INVALID_SQRT
 113 # define FP_EX_INVALID_SQRT     0
 114 #endif
 115 /* Invalid conversion to integer.  */
 116 #ifndef FP_EX_INVALID_CVI
 117 # define FP_EX_INVALID_CVI      0
 118 #endif
 119 /* Invalid comparison.  */
 120 #ifndef FP_EX_INVALID_VC
 121 # define FP_EX_INVALID_VC       0
 122 #endif
 123
 124 /* _FP_STRUCT_LAYOUT may be defined as an attribute to determine the
 125    struct layout variant used for structures where bit-fields are used
 126    to access specific parts of binary floating-point numbers.  This is
 127    required for systems where the default ABI uses struct layout with
 128    differences in how consecutive bit-fields are laid out from the
 129    default expected by soft-fp.  */
 130 #ifndef _FP_STRUCT_LAYOUT
 131 # define _FP_STRUCT_LAYOUT
 132 #endif
 133
 134 #ifdef _FP_DECL_EX
 135 # define FP_DECL_EX                                     \
 136   int _fex = 0;                                         \
 137   _FP_DECL_EX
 138 #else
 139 # define FP_DECL_EX int _fex = 0
 140 #endif
 141
 142 /* Initialize any machine-specific state used in FP_ROUNDMODE,
 143    FP_TRAPPING_EXCEPTIONS or FP_HANDLE_EXCEPTIONS.  */
 144 #ifndef FP_INIT_ROUNDMODE
 145 # define FP_INIT_ROUNDMODE do {} while (0)
 146 #endif
 147
 148 /* Initialize any machine-specific state used in
 149    FP_TRAPPING_EXCEPTIONS or FP_HANDLE_EXCEPTIONS.  */
 150 #ifndef FP_INIT_TRAPPING_EXCEPTIONS
 151 # define FP_INIT_TRAPPING_EXCEPTIONS FP_INIT_ROUNDMODE
 152 #endif
 153
 154 /* Initialize any machine-specific state used in
 155    FP_HANDLE_EXCEPTIONS.  */
 156 #ifndef FP_INIT_EXCEPTIONS
 157 # define FP_INIT_EXCEPTIONS FP_INIT_TRAPPING_EXCEPTIONS
 158 #endif
 159
 160 #ifndef FP_HANDLE_EXCEPTIONS
 161 # define FP_HANDLE_EXCEPTIONS do {} while (0)
 162 #endif
 163
 164 /* Whether to flush subnormal inputs to zero with the same sign.  */
 165 #ifndef FP_DENORM_ZERO
 166 # define FP_DENORM_ZERO 0
 167 #endif
 168
 169 #ifndef FP_INHIBIT_RESULTS
 170 /* By default we write the results always.
 171    sfp-machine may override this and e.g.
 172    check if some exceptions are unmasked
 173    and inhibit it in such a case.  */
 174 # define FP_INHIBIT_RESULTS 0
 175 #endif
 176
 177 #define FP_SET_EXCEPTION(ex)                            \
 178   _fex |= (ex)
 179
 180 #define FP_CUR_EXCEPTIONS                               \
 181   (_fex)
 182
 183 #ifndef FP_TRAPPING_EXCEPTIONS
 184 # define FP_TRAPPING_EXCEPTIONS 0
 185 #endif
 186
 187 /* A file using soft-fp may define FP_NO_EXCEPTIONS before including
 188    soft-fp.h to indicate that, although a macro used there could raise
 189    exceptions, or do rounding and potentially thereby raise
 190    exceptions, for some arguments, for the particular arguments used
 191    in that file no exceptions or rounding can occur.  Such a file
 192    should not itself use macros relating to handling exceptions and
 193    rounding modes; this is only for indirect uses (in particular, in
 194    _FP_FROM_INT and the macros it calls).  */
 195 #ifdef FP_NO_EXCEPTIONS
 196
 197 # undef FP_SET_EXCEPTION
 198 # define FP_SET_EXCEPTION(ex) do {} while (0)
 199
 200 # undef FP_CUR_EXCEPTIONS
 201 # define FP_CUR_EXCEPTIONS 0
 202
 203 # undef FP_TRAPPING_EXCEPTIONS
 204 # define FP_TRAPPING_EXCEPTIONS 0
 205
 206 # undef FP_ROUNDMODE
 207 # define FP_ROUNDMODE FP_RND_ZERO
 208
 209 # undef _FP_TININESS_AFTER_ROUNDING
 210 # define _FP_TININESS_AFTER_ROUNDING 0
 211
 212 #endif
 213
 214 /* A file using soft-fp may define FP_NO_EXACT_UNDERFLOW before
 215    including soft-fp.h to indicate that, although a macro used there
 216    could allow for the case of exact underflow requiring the underflow
 217    exception to be raised if traps are enabled, for the particular
 218    arguments used in that file no exact underflow can occur.  */
 219 #ifdef FP_NO_EXACT_UNDERFLOW
 220 # undef FP_TRAPPING_EXCEPTIONS
 221 # define FP_TRAPPING_EXCEPTIONS 0
 222 #endif
 223
 224 #define _FP_ROUND_NEAREST(wc, X)                                \
 225   do                                                            \
 226     {                                                           \
 227       if ((_FP_FRAC_LOW_##wc (X) & 15) != _FP_WORK_ROUND)       \
 228         _FP_FRAC_ADDI_##wc (X, _FP_WORK_ROUND);                 \
 229     }                                                           \
 230   while (0)
 231
 232 #define _FP_ROUND_ZERO(wc, X)           (void) 0
 233
 234 #define _FP_ROUND_PINF(wc, X)                           \
 235   do                                                    \
 236     {                                                   \
 237       if (!X##_s && (_FP_FRAC_LOW_##wc (X) & 7))        \
 238         _FP_FRAC_ADDI_##wc (X, _FP_WORK_LSB);           \
 239     }                                                   \
 240   while (0)
 241
 242 #define _FP_ROUND_MINF(wc, X)                   \
 243   do                                            \
 244     {                                           \
 245       if (X##_s && (_FP_FRAC_LOW_##wc (X) & 7)) \
 246         _FP_FRAC_ADDI_##wc (X, _FP_WORK_LSB);   \
 247     }                                           \
 248   while (0)
 249
 250 #define _FP_ROUND(wc, X)                        \
 251   do                                            \
 252     {                                           \
 253       if (_FP_FRAC_LOW_##wc (X) & 7)            \
 254         {                                       \
 255           FP_SET_EXCEPTION (FP_EX_INEXACT);     \
 256           switch (FP_ROUNDMODE)                 \
 257             {                                   \
 258             case FP_RND_NEAREST:                \
 259               _FP_ROUND_NEAREST (wc, X);        \
 260               break;                            \
 261             case FP_RND_ZERO:                   \
 262               _FP_ROUND_ZERO (wc, X);           \
 263               break;                            \
 264             case FP_RND_PINF:                   \
 265               _FP_ROUND_PINF (wc, X);           \
 266               break;                            \
 267             case FP_RND_MINF:                   \
 268               _FP_ROUND_MINF (wc, X);           \
 269               break;                            \
 270             }                                   \
 271         }                                       \
 272     }                                           \
 273   while (0)
 274
 275 #define FP_CLS_NORMAL           0
 276 #define FP_CLS_ZERO             1
 277 #define FP_CLS_INF              2
 278 #define FP_CLS_NAN              3
 279
 280 #define _FP_CLS_COMBINE(x, y)   (((x) << 2) | (y))
 281
 282 #include "op-1.h"
 283 #include "op-2.h"
 284 #include "op-4.h"
 285 #include "op-8.h"
 286 #include "op-common.h"
 287
 288 /* Sigh.  Silly things longlong.h needs.  */
 289 #define UWtype          _FP_W_TYPE
 290 #define W_TYPE_SIZE     _FP_W_TYPE_SIZE
 291
 292 typedef int QItype __attribute__ ((mode (QI)));
 293 typedef int SItype __attribute__ ((mode (SI)));
 294 typedef int DItype __attribute__ ((mode (DI)));
 295 typedef unsigned int UQItype __attribute__ ((mode (QI)));
 296 typedef unsigned int USItype __attribute__ ((mode (SI)));
 297 typedef unsigned int UDItype __attribute__ ((mode (DI)));
 298 #if _FP_W_TYPE_SIZE == 32
 299 typedef unsigned int UHWtype __attribute__ ((mode (HI)));
 300 #elif _FP_W_TYPE_SIZE == 64
 301 typedef USItype UHWtype;
 302 #endif
 303
 304 #ifndef CMPtype
 305 # define CMPtype        int
 306 #endif
 307
 308 #define SI_BITS         (__CHAR_BIT__ * (int) sizeof (SItype))
 309 #define DI_BITS         (__CHAR_BIT__ * (int) sizeof (DItype))
 310
 311 #ifndef umul_ppmm
 312 # ifdef _LIBC
 313 #  include <stdlib/longlong.h>
 314 # else
 315 #  include "longlong.h"
 316 # endif
 317 #endif
 318
 319 #ifdef _LIBC
 320 # include <stdlib.h>
 321 #else
 322 extern void abort (void);
 323 #endif
 324
 325 #endif