sys/lib/libkern/softfloat.h

   1 /* $NetBSD: softfloat.h,v 1.3 2006/02/16 20:17:20 perry Exp $ */
   2
   3 /* This is a derivative work. */
   4
   5 /*-
   6  * Copyright (c) 2001 The NetBSD Foundation, Inc.
   7  * All rights reserved.
   8  *
   9  * This code is derived from software contributed to The NetBSD Foundation
  10  * by Ross Harvey.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions and the following disclaimer.
  17  * 2. Redistributions in binary form must reproduce the above copyright
  18  *    notice, this list of conditions and the following disclaimer in the
  19  *    documentation and/or other materials provided with the distribution.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  23  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  24  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  25  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  26  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  27  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  28  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  29  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  30  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  31  * POSSIBILITY OF SUCH DAMAGE.
  32  */
  33
  34 /*
  35 ===============================================================================
  36
  37 This C header file is part of the SoftFloat IEC/IEEE Floating-point
  38 Arithmetic Package, Release 2a.
  39
  40 Written by John R. Hauser.  This work was made possible in part by the
  41 International Computer Science Institute, located at Suite 600, 1947 Center
  42 Street, Berkeley, California 94704.  Funding was partially provided by the
  43 National Science Foundation under grant MIP-9311980.  The original version
  44 of this code was written as part of a project to build a fixed-point vector
  45 processor in collaboration with the University of California at Berkeley,
  46 overseen by Profs. Nelson Morgan and John Wawrzynek.  More information
  47 is available through the Web page `http://HTTP.CS.Berkeley.EDU/~jhauser/
  48 arithmetic/SoftFloat.html'.
  49
  50 THIS SOFTWARE IS DISTRIBUTED AS IS, FOR FREE.  Although reasonable effort
  51 has been made to avoid it, THIS SOFTWARE MAY CONTAIN FAULTS THAT WILL AT
  52 TIMES RESULT IN INCORRECT BEHAVIOR.  USE OF THIS SOFTWARE IS RESTRICTED TO
  53 PERSONS AND ORGANIZATIONS WHO CAN AND WILL TAKE FULL RESPONSIBILITY FOR ANY
  54 AND ALL LOSSES, COSTS, OR OTHER PROBLEMS ARISING FROM ITS USE.
  55
  56 Derivative works are acceptable, even for commercial purposes, so long as
  57 (1) they include prominent notice that the work is derivative, and (2) they
  58 include prominent notice akin to these four paragraphs for those parts of
  59 this code that are retained.
  60
  61 ===============================================================================
  62 */
  63
  64 #include <sys/types.h>
  65
  66 #if !defined(_KERNEL) && !defined(_STANDALONE)
  67 #include <inttypes.h>
  68 #include <ieeefp.h>
  69 #else
  70 #include "sys/inttypes.h"
  71 #include "machine/ieeefp.h"
  72 #endif
  73 #include <sys/endian.h>
  74
  75 /*
  76 -------------------------------------------------------------------------------
  77 The macro `FLOATX80' must be defined to enable the extended double-precision
  78 floating-point format `floatx80'.  If this macro is not defined, the
  79 `floatx80' type will not be defined, and none of the functions that either
  80 input or output the `floatx80' type will be defined.  The same applies to
  81 the `FLOAT128' macro and the quadruple-precision format `float128'.
  82 -------------------------------------------------------------------------------
  83 */
  84 /* #define FLOATX80 */
  85 /* #define FLOAT128 */
  86
  87 /*
  88 -------------------------------------------------------------------------------
  89 Software IEC/IEEE floating-point types.
  90 -------------------------------------------------------------------------------
  91 */
  92 typedef u_int32_t float32;
  93 typedef u_int64_t float64;
  94 #ifdef FLOATX80
  95 typedef struct {
  96 #if BYTE_ORDER == BIG_ENDIAN
  97     u_int16_t high;
  98     u_int64_t low;
  99 #else
 100     u_int64_t low;
 101     u_int16_t high;
 102 #endif
 103 } floatx80;
 104 #endif
 105 #ifdef FLOAT128
 106 typedef struct {
 107     u_int64_t high, low;
 108 } float128;
 109 #endif
 110
 111 /*
 112  * Some of the global variables that used to be here have been removed for
 113  * fairly obvious (defopt-MULTIPROCESSOR) reasons.  The rest (which don't
 114  * change dynamically) will be removed later. [ross]
 115  */
 116
 117 #define float_rounding_mode() fpgetround()
 118
 119 /*
 120 -------------------------------------------------------------------------------
 121 Software IEC/IEEE floating-point underflow tininess-detection mode.
 122 -------------------------------------------------------------------------------
 123 */
 124
 125 extern int float_detect_tininess;
 126 enum {
 127     float_tininess_after_rounding  = 1,
 128     float_tininess_before_rounding = 0
 129 };
 130
 131 /*
 132 -------------------------------------------------------------------------------
 133 Software IEC/IEEE floating-point rounding mode.
 134 -------------------------------------------------------------------------------
 135 */
 136
 137 enum {
 138     float_round_nearest_even = FP_RN,
 139     float_round_to_zero      = FP_RZ,
 140     float_round_down         = FP_RM,
 141     float_round_up           = FP_RP
 142 };
 143
 144 /*
 145 -------------------------------------------------------------------------------
 146 Software IEC/IEEE floating-point exception flags.
 147 -------------------------------------------------------------------------------
 148 */
 149
 150 enum {
 151     float_flag_inexact   =  FP_X_IMP,
 152     float_flag_underflow =  FP_X_UFL,
 153     float_flag_overflow  =  FP_X_OFL,
 154     float_flag_divbyzero =  FP_X_DZ,
 155     float_flag_invalid   =  FP_X_INV
 156 };
 157
 158 /*
 159 -------------------------------------------------------------------------------
 160 Software IEC/IEEE integer-to-floating-point conversion routines.
 161 -------------------------------------------------------------------------------
 162 */
 163 float32 int32_to_float32( int );
 164 float64 int32_to_float64( int );
 165 #ifdef FLOATX80
 166 floatx80 int32_to_floatx80( int );
 167 #endif
 168 #ifdef FLOAT128
 169 float128 int32_to_float128( int );
 170 #endif
 171 #ifndef SOFTFLOAT_FOR_GCC /* __floatdi?f is in libgcc2.c */
 172 float32 int64_to_float32( int64_t );
 173 float64 int64_to_float64( int64_t );
 174 #ifdef FLOATX80
 175 floatx80 int64_to_floatx80( int64_t );
 176 #endif
 177 #ifdef FLOAT128
 178 float128 int64_to_float128( int64_t );
 179 #endif
 180 #endif
 181
 182 /*
 183 -------------------------------------------------------------------------------
 184 Software IEC/IEEE single-precision conversion routines.
 185 -------------------------------------------------------------------------------
 186 */
 187 int float32_to_int32( float32 );
 188 int float32_to_int32_round_to_zero( float32 );
 189 #ifndef SOFTFLOAT_FOR_GCC /* __fix?fdi provided by libgcc2.c */
 190 int64_t float32_to_int64( float32 );
 191 int64_t float32_to_int64_round_to_zero( float32 );
 192 #endif
 193 float64 float32_to_float64( float32 );
 194 #ifdef FLOATX80
 195 floatx80 float32_to_floatx80( float32 );
 196 #endif
 197 #ifdef FLOAT128
 198 float128 float32_to_float128( float32 );
 199 #endif
 200
 201 /*
 202 -------------------------------------------------------------------------------
 203 Software IEC/IEEE single-precision operations.
 204 -------------------------------------------------------------------------------
 205 */
 206 float32 float32_round_to_int( float32 );
 207 float32 float32_add( float32, float32 );
 208 float32 float32_sub( float32, float32 );
 209 float32 float32_mul( float32, float32 );
 210 float32 float32_div( float32, float32 );
 211 float32 float32_rem( float32, float32 );
 212 float32 float32_sqrt( float32 );
 213 int float32_eq( float32, float32 );
 214 int float32_le( float32, float32 );
 215 int float32_lt( float32, float32 );
 216 int float32_eq_signaling( float32, float32 );
 217 int float32_le_quiet( float32, float32 );
 218 int float32_lt_quiet( float32, float32 );
 219 #ifndef SOFTFLOAT_FOR_GCC
 220 int float32_is_signaling_nan( float32 );
 221 #endif
 222
 223 /*
 224 -------------------------------------------------------------------------------
 225 Software IEC/IEEE double-precision conversion routines.
 226 -------------------------------------------------------------------------------
 227 */
 228 int float64_to_int32( float64 );
 229 int float64_to_int32_round_to_zero( float64 );
 230 #ifndef SOFTFLOAT_FOR_GCC /* __fix?fdi provided by libgcc2.c */
 231 int64_t float64_to_int64( float64 );
 232 int64_t float64_to_int64_round_to_zero( float64 );
 233 #endif
 234 float32 float64_to_float32( float64 );
 235 #ifdef FLOATX80
 236 floatx80 float64_to_floatx80( float64 );
 237 #endif
 238 #ifdef FLOAT128
 239 float128 float64_to_float128( float64 );
 240 #endif
 241
 242 /*
 243 -------------------------------------------------------------------------------
 244 Software IEC/IEEE double-precision operations.
 245 -------------------------------------------------------------------------------
 246 */
 247 #define float64_default_nan 0xFFF8000000000000LL
 248
 249 static __inline int
 250 float64_is_nan(float64 a)
 251 {
 252         return 0xFFE0000000000000LL < a << 1;
 253 }
 254
 255 static __inline int
 256 float64_is_signaling_nan(float64 a)
 257 {
 258         return (a >> 51 & 0xFFF) == 0xFFE && (a & 0x0007FFFFFFFFFFFFLL);
 259 }
 260
 261 float64 float64_round_to_int( float64 );
 262 float64 float64_add( float64, float64 );
 263 float64 float64_sub( float64, float64 );
 264 float64 float64_mul( float64, float64 );
 265 float64 float64_div( float64, float64 );
 266 float64 float64_rem( float64, float64 );
 267 float64 float64_sqrt( float64 );
 268 int float64_eq( float64, float64 );
 269 int float64_le( float64, float64 );
 270 int float64_lt( float64, float64 );
 271 int float64_eq_signaling( float64, float64 );
 272 int float64_le_quiet( float64, float64 );
 273 int float64_lt_quiet( float64, float64 );
 274 #ifndef SOFTFLOAT_FOR_GCC
 275 int float64_is_signaling_nan( float64 );
 276 #endif
 277
 278 #ifdef FLOATX80
 279
 280 /*
 281 -------------------------------------------------------------------------------
 282 Software IEC/IEEE extended double-precision conversion routines.
 283 -------------------------------------------------------------------------------
 284 */
 285 int floatx80_to_int32( floatx80 );
 286 int floatx80_to_int32_round_to_zero( floatx80 );
 287 int64_t floatx80_to_int64( floatx80 );
 288 int64_t floatx80_to_int64_round_to_zero( floatx80 );
 289 float32 floatx80_to_float32( floatx80 );
 290 float64 floatx80_to_float64( floatx80 );
 291 #ifdef FLOAT128
 292 float128 floatx80_to_float128( floatx80 );
 293 #endif
 294
 295 /*
 296 -------------------------------------------------------------------------------
 297 Software IEC/IEEE extended double-precision rounding precision.  Valid
 298 values are 32, 64, and 80.
 299 -------------------------------------------------------------------------------
 300 */
 301 extern int floatx80_rounding_precision;
 302
 303 /*
 304 -------------------------------------------------------------------------------
 305 Software IEC/IEEE extended double-precision operations.
 306 -------------------------------------------------------------------------------
 307 */
 308 floatx80 floatx80_round_to_int( floatx80 );
 309 floatx80 floatx80_add( floatx80, floatx80 );
 310 floatx80 floatx80_sub( floatx80, floatx80 );
 311 floatx80 floatx80_mul( floatx80, floatx80 );
 312 floatx80 floatx80_div( floatx80, floatx80 );
 313 floatx80 floatx80_rem( floatx80, floatx80 );
 314 floatx80 floatx80_sqrt( floatx80 );
 315 int floatx80_eq( floatx80, floatx80 );
 316 int floatx80_le( floatx80, floatx80 );
 317 int floatx80_lt( floatx80, floatx80 );
 318 int floatx80_eq_signaling( floatx80, floatx80 );
 319 int floatx80_le_quiet( floatx80, floatx80 );
 320 int floatx80_lt_quiet( floatx80, floatx80 );
 321 int floatx80_is_signaling_nan( floatx80 );
 322
 323 #endif
 324
 325 #ifdef FLOAT128
 326
 327 /*
 328 -------------------------------------------------------------------------------
 329 Software IEC/IEEE quadruple-precision conversion routines.
 330 -------------------------------------------------------------------------------
 331 */
 332 int float128_to_int32( float128 );
 333 int float128_to_int32_round_to_zero( float128 );
 334 int64_t float128_to_int64( float128 );
 335 int64_t float128_to_int64_round_to_zero( float128 );
 336 float32 float128_to_float32( float128 );
 337 float64 float128_to_float64( float128 );
 338 #ifdef FLOATX80
 339 floatx80 float128_to_floatx80( float128 );
 340 #endif
 341
 342 /*
 343 -------------------------------------------------------------------------------
 344 Software IEC/IEEE quadruple-precision operations.
 345 -------------------------------------------------------------------------------
 346 */
 347 float128 float128_round_to_int( float128 );
 348 float128 float128_add( float128, float128 );
 349 float128 float128_sub( float128, float128 );
 350 float128 float128_mul( float128, float128 );
 351 float128 float128_div( float128, float128 );
 352 float128 float128_rem( float128, float128 );
 353 float128 float128_sqrt( float128 );
 354 int float128_eq( float128, float128 );
 355 int float128_le( float128, float128 );
 356 int float128_lt( float128, float128 );
 357 int float128_eq_signaling( float128, float128 );
 358 int float128_le_quiet( float128, float128 );
 359 int float128_lt_quiet( float128, float128 );
 360 int float128_is_signaling_nan( float128 );
 361
 362 #endif
 363