1/* Software floating-point emulation.
2 Copyright (C) 1997-2021 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 <https://www.gnu.org/licenses/>. */
31
32#ifndef SOFT_FP_H
33#define SOFT_FP_H 1
34
35#ifdef _LIBC
36# include <sfp-machine.h>
37#elif defined __KERNEL__
38/* The Linux kernel uses asm/ names for architecture-specific
39 files. */
40# include <asm/sfp-machine.h>
41#else
42# include "sfp-machine.h"
43#endif
44
45/* Allow sfp-machine to have its own byte order definitions. */
46#ifndef __BYTE_ORDER
47# ifdef _LIBC
48# include <endian.h>
49# else
50# error "endianness not defined by sfp-machine.h"
51# endif
52#endif
53
54/* For unreachable default cases in switch statements over bitwise OR
55 of FP_CLS_* values. */
56#if (defined __GNUC__ \
57 && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)))
58# define _FP_UNREACHABLE __builtin_unreachable ()
59#else
60# define _FP_UNREACHABLE abort ()
61#endif
62
63#if ((defined __GNUC__ \
64 && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6))) \
65 || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 201112L))
66# define _FP_STATIC_ASSERT(expr, msg) \
67 _Static_assert ((expr), msg)
68#else
69# define _FP_STATIC_ASSERT(expr, msg) \
70 extern int (*__Static_assert_function (void)) \
71 [!!sizeof (struct { int __error_if_negative: (expr) ? 2 : -1; })]
72#endif
73
74/* In the Linux kernel, some architectures have a single function that
75 uses different kinds of unpacking and packing depending on the
76 instruction being emulated, meaning it is not readily visible to
77 the compiler that variables from _FP_DECL and _FP_FRAC_DECL_*
78 macros are only used in cases where they were initialized. */
79#ifdef __KERNEL__
80# define _FP_ZERO_INIT = 0
81#else
82# define _FP_ZERO_INIT
83#endif
84
85#define _FP_WORKBITS 3
86#define _FP_WORK_LSB ((_FP_W_TYPE) 1 << 3)
87#define _FP_WORK_ROUND ((_FP_W_TYPE) 1 << 2)
88#define _FP_WORK_GUARD ((_FP_W_TYPE) 1 << 1)
89#define _FP_WORK_STICKY ((_FP_W_TYPE) 1 << 0)
90
91#ifndef FP_RND_NEAREST
92# define FP_RND_NEAREST 0
93# define FP_RND_ZERO 1
94# define FP_RND_PINF 2
95# define FP_RND_MINF 3
96#endif
97#ifndef FP_ROUNDMODE
98# define FP_ROUNDMODE FP_RND_NEAREST
99#endif
100
101/* By default don't care about exceptions. */
102#ifndef FP_EX_INVALID
103# define FP_EX_INVALID 0
104#endif
105#ifndef FP_EX_OVERFLOW
106# define FP_EX_OVERFLOW 0
107#endif
108#ifndef FP_EX_UNDERFLOW
109# define FP_EX_UNDERFLOW 0
110#endif
111#ifndef FP_EX_DIVZERO
112# define FP_EX_DIVZERO 0
113#endif
114#ifndef FP_EX_INEXACT
115# define FP_EX_INEXACT 0
116#endif
117#ifndef FP_EX_DENORM
118# define FP_EX_DENORM 0
119#endif
120
121/* Sub-exceptions of "invalid". */
122/* Signaling NaN operand. */
123#ifndef FP_EX_INVALID_SNAN
124# define FP_EX_INVALID_SNAN 0
125#endif
126/* Inf * 0. */
127#ifndef FP_EX_INVALID_IMZ
128# define FP_EX_INVALID_IMZ 0
129#endif
130/* fma (Inf, 0, c). */
131#ifndef FP_EX_INVALID_IMZ_FMA
132# define FP_EX_INVALID_IMZ_FMA 0
133#endif
134/* Inf - Inf. */
135#ifndef FP_EX_INVALID_ISI
136# define FP_EX_INVALID_ISI 0
137#endif
138/* 0 / 0. */
139#ifndef FP_EX_INVALID_ZDZ
140# define FP_EX_INVALID_ZDZ 0
141#endif
142/* Inf / Inf. */
143#ifndef FP_EX_INVALID_IDI
144# define FP_EX_INVALID_IDI 0
145#endif
146/* sqrt (negative). */
147#ifndef FP_EX_INVALID_SQRT
148# define FP_EX_INVALID_SQRT 0
149#endif
150/* Invalid conversion to integer. */
151#ifndef FP_EX_INVALID_CVI
152# define FP_EX_INVALID_CVI 0
153#endif
154/* Invalid comparison. */
155#ifndef FP_EX_INVALID_VC
156# define FP_EX_INVALID_VC 0
157#endif
158
159/* _FP_STRUCT_LAYOUT may be defined as an attribute to determine the
160 struct layout variant used for structures where bit-fields are used
161 to access specific parts of binary floating-point numbers. This is
162 required for systems where the default ABI uses struct layout with
163 differences in how consecutive bit-fields are laid out from the
164 default expected by soft-fp. */
165#ifndef _FP_STRUCT_LAYOUT
166# define _FP_STRUCT_LAYOUT
167#endif
168
169#ifdef _FP_DECL_EX
170# define FP_DECL_EX \
171 int _fex = 0; \
172 _FP_DECL_EX
173#else
174# define FP_DECL_EX int _fex = 0
175#endif
176
177/* Initialize any machine-specific state used in FP_ROUNDMODE,
178 FP_TRAPPING_EXCEPTIONS or FP_HANDLE_EXCEPTIONS. */
179#ifndef FP_INIT_ROUNDMODE
180# define FP_INIT_ROUNDMODE do {} while (0)
181#endif
182
183/* Initialize any machine-specific state used in
184 FP_TRAPPING_EXCEPTIONS or FP_HANDLE_EXCEPTIONS. */
185#ifndef FP_INIT_TRAPPING_EXCEPTIONS
186# define FP_INIT_TRAPPING_EXCEPTIONS FP_INIT_ROUNDMODE
187#endif
188
189/* Initialize any machine-specific state used in
190 FP_HANDLE_EXCEPTIONS. */
191#ifndef FP_INIT_EXCEPTIONS
192# define FP_INIT_EXCEPTIONS FP_INIT_TRAPPING_EXCEPTIONS
193#endif
194
195#ifndef FP_HANDLE_EXCEPTIONS
196# define FP_HANDLE_EXCEPTIONS do {} while (0)
197#endif
198
199/* Whether to flush subnormal inputs to zero with the same sign. */
200#ifndef FP_DENORM_ZERO
201# define FP_DENORM_ZERO 0
202#endif
203
204#ifndef FP_INHIBIT_RESULTS
205/* By default we write the results always.
206 sfp-machine may override this and e.g.
207 check if some exceptions are unmasked
208 and inhibit it in such a case. */
209# define FP_INHIBIT_RESULTS 0
210#endif
211
212#define FP_SET_EXCEPTION(ex) \
213 _fex |= (ex)
214
215#define FP_CUR_EXCEPTIONS \
216 (_fex)
217
218#ifndef FP_TRAPPING_EXCEPTIONS
219# define FP_TRAPPING_EXCEPTIONS 0
220#endif
221
222/* A file using soft-fp may define FP_NO_EXCEPTIONS before including
223 soft-fp.h to indicate that, although a macro used there could raise
224 exceptions, or do rounding and potentially thereby raise
225 exceptions, for some arguments, for the particular arguments used
226 in that file no exceptions or rounding can occur. Such a file
227 should not itself use macros relating to handling exceptions and
228 rounding modes; this is only for indirect uses (in particular, in
229 _FP_FROM_INT and the macros it calls). */
230#ifdef FP_NO_EXCEPTIONS
231
232# undef FP_SET_EXCEPTION
233# define FP_SET_EXCEPTION(ex) do {} while (0)
234
235# undef FP_CUR_EXCEPTIONS
236# define FP_CUR_EXCEPTIONS 0
237
238# undef FP_TRAPPING_EXCEPTIONS
239# define FP_TRAPPING_EXCEPTIONS 0
240
241# undef FP_ROUNDMODE
242# define FP_ROUNDMODE FP_RND_ZERO
243
244# undef _FP_TININESS_AFTER_ROUNDING
245# define _FP_TININESS_AFTER_ROUNDING 0
246
247#endif
248
249/* A file using soft-fp may define FP_NO_EXACT_UNDERFLOW before
250 including soft-fp.h to indicate that, although a macro used there
251 could allow for the case of exact underflow requiring the underflow
252 exception to be raised if traps are enabled, for the particular
253 arguments used in that file no exact underflow can occur. */
254#ifdef FP_NO_EXACT_UNDERFLOW
255# undef FP_TRAPPING_EXCEPTIONS
256# define FP_TRAPPING_EXCEPTIONS 0
257#endif
258
259#define _FP_ROUND_NEAREST(wc, X) \
260 do \
261 { \
262 if ((_FP_FRAC_LOW_##wc (X) & 15) != _FP_WORK_ROUND) \
263 _FP_FRAC_ADDI_##wc (X, _FP_WORK_ROUND); \
264 } \
265 while (0)
266
267#define _FP_ROUND_ZERO(wc, X) (void) 0
268
269#define _FP_ROUND_PINF(wc, X) \
270 do \
271 { \
272 if (!X##_s && (_FP_FRAC_LOW_##wc (X) & 7)) \
273 _FP_FRAC_ADDI_##wc (X, _FP_WORK_LSB); \
274 } \
275 while (0)
276
277#define _FP_ROUND_MINF(wc, X) \
278 do \
279 { \
280 if (X##_s && (_FP_FRAC_LOW_##wc (X) & 7)) \
281 _FP_FRAC_ADDI_##wc (X, _FP_WORK_LSB); \
282 } \
283 while (0)
284
285#define _FP_ROUND(wc, X) \
286 do \
287 { \
288 if (_FP_FRAC_LOW_##wc (X) & 7) \
289 { \
290 FP_SET_EXCEPTION (FP_EX_INEXACT); \
291 switch (FP_ROUNDMODE) \
292 { \
293 case FP_RND_NEAREST: \
294 _FP_ROUND_NEAREST (wc, X); \
295 break; \
296 case FP_RND_ZERO: \
297 _FP_ROUND_ZERO (wc, X); \
298 break; \
299 case FP_RND_PINF: \
300 _FP_ROUND_PINF (wc, X); \
301 break; \
302 case FP_RND_MINF: \
303 _FP_ROUND_MINF (wc, X); \
304 break; \
305 } \
306 } \
307 } \
308 while (0)
309
310#define FP_CLS_NORMAL 0
311#define FP_CLS_ZERO 1
312#define FP_CLS_INF 2
313#define FP_CLS_NAN 3
314
315#define _FP_CLS_COMBINE(x, y) (((x) << 2) | (y))
316
317#include "op-1.h"
318#include "op-2.h"
319#include "op-4.h"
320#include "op-8.h"
321#include "op-common.h"
322
323/* Sigh. Silly things longlong.h needs. */
324#define UWtype _FP_W_TYPE
325#define W_TYPE_SIZE _FP_W_TYPE_SIZE
326
327typedef int QItype __attribute__ ((mode (QI)));
328typedef int SItype __attribute__ ((mode (SI)));
329typedef int DItype __attribute__ ((mode (DI)));
330typedef unsigned int UQItype __attribute__ ((mode (QI)));
331typedef unsigned int USItype __attribute__ ((mode (SI)));
332typedef unsigned int UDItype __attribute__ ((mode (DI)));
333#if _FP_W_TYPE_SIZE == 32
334typedef unsigned int UHWtype __attribute__ ((mode (HI)));
335#elif _FP_W_TYPE_SIZE == 64
336typedef USItype UHWtype;
337#endif
338
339#ifndef CMPtype
340# define CMPtype int
341#endif
342
343#define SI_BITS (__CHAR_BIT__ * (int) sizeof (SItype))
344#define DI_BITS (__CHAR_BIT__ * (int) sizeof (DItype))
345
346#ifndef umul_ppmm
347# ifdef _LIBC
348# include <stdlib/longlong.h>
349# else
350# include "longlong.h"
351# endif
352#endif
353
354#endif /* !SOFT_FP_H */
355