1 /* A GNU-like <math.h>.
3 Copyright (C) 2002-2003, 2007-2010 Free Software Foundation, Inc.
5 This program is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 3 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>. */
21 @PRAGMA_SYSTEM_HEADER@
24 /* The include_next requires a split double-inclusion guard. */
25 #@INCLUDE_NEXT_AS_FIRST_DIRECTIVE@ @NEXT_AS_FIRST_DIRECTIVE_MATH_H@
31 /* The definitions of _GL_FUNCDECL_RPL etc. are copied here. */
33 /* The definition of _GL_ARG_NONNULL is copied here. */
35 /* The definition of _GL_WARN_ON_USE is copied here. */
37 /* Helper macros to define a portability warning for the
38 classification macro FUNC called with VALUE. POSIX declares the
39 classification macros with an argument of real-floating (that is,
40 one of float, double, or long double). */
41 #define _GL_WARN_REAL_FLOATING_DECL(func) \
43 rpl_ ## func ## f (float f) \
48 rpl_ ## func ## d (double d) \
53 rpl_ ## func ## l (long double l) \
57 _GL_WARN_ON_USE (rpl_ ## func ## f, #func " is unportable - " \
58 "use gnulib module " #func " for portability"); \
59 _GL_WARN_ON_USE (rpl_ ## func ## d, #func " is unportable - " \
60 "use gnulib module " #func " for portability"); \
61 _GL_WARN_ON_USE (rpl_ ## func ## l, #func " is unportable - " \
62 "use gnulib module " #func " for portability")
63 #define _GL_WARN_REAL_FLOATING_IMPL(func, value) \
64 (sizeof (value) == sizeof (float) ? rpl_ ## func ## f (value) \
65 : sizeof (value) == sizeof (double) ? rpl_ ## func ## d (value) \
66 : rpl_ ## func ## l (value))
69 /* POSIX allows platforms that don't support NAN. But all major
70 machines in the past 15 years have supported something close to
71 IEEE NaN, so we define this unconditionally. We also must define
72 it on platforms like Solaris 10, where NAN is present but defined
73 as a function pointer rather than a floating point constant. */
74 #if !defined NAN || @REPLACE_NAN@
76 /* The Compaq (ex-DEC) C 6.4 compiler chokes on the expression 0.0 / 0.0. */
81 static float zero = 0.0f;
86 # define NAN (0.0f / 0.0f)
90 /* Solaris 10 defines HUGE_VAL, but as a function pointer rather
91 than a floating point constant. */
92 #if @REPLACE_HUGE_VAL@
94 # define HUGE_VAL (1.0 / 0.0)
101 If x finite and nonzero: 0.5 <= |mantissa| < 1.0.
102 If x is zero: mantissa = x, exp = 0.
103 If x is infinite or NaN: mantissa = x, exp unspecified.
104 Store exp in *EXPPTR and return mantissa. */
107 # if !(defined __cplusplus && defined GNULIB_NAMESPACE)
108 # define frexp rpl_frexp
110 _GL_FUNCDECL_RPL (frexp, double, (double x, int *expptr) _GL_ARG_NONNULL ((2)));
111 _GL_CXXALIAS_RPL (frexp, double, (double x, int *expptr));
113 _GL_CXXALIAS_SYS (frexp, double, (double x, int *expptr));
115 _GL_CXXALIASWARN (frexp);
116 #elif defined GNULIB_POSIXCHECK
118 /* Assume frexp is always declared. */
119 _GL_WARN_ON_USE (frexp, "frexp is unportable - "
120 "use gnulib module frexp for portability");
125 # if !@HAVE_DECL_LOGB@
126 _GL_EXTERN_C double logb (double x);
128 #elif defined GNULIB_POSIXCHECK
130 # if HAVE_RAW_DECL_LOGB
131 _GL_WARN_ON_USE (logb, "logb is unportable - "
132 "use gnulib module logb for portability");
138 # if !@HAVE_ACOSL@ || !@HAVE_DECL_ACOSL@
139 _GL_FUNCDECL_SYS (acosl, long double, (long double x));
141 _GL_CXXALIAS_SYS (acosl, long double, (long double x));
142 _GL_CXXALIASWARN (acosl);
143 #elif defined GNULIB_POSIXCHECK
145 # if HAVE_RAW_DECL_ACOSL
146 _GL_WARN_ON_USE (acosl, "acosl is unportable - "
147 "use gnulib module mathl for portability");
153 # if !@HAVE_ASINL@ || !@HAVE_DECL_ASINL@
154 _GL_FUNCDECL_SYS (asinl, long double, (long double x));
156 _GL_CXXALIAS_SYS (asinl, long double, (long double x));
157 _GL_CXXALIASWARN (asinl);
158 #elif defined GNULIB_POSIXCHECK
160 # if HAVE_RAW_DECL_ASINL
161 _GL_WARN_ON_USE (asinl, "asinl is unportable - "
162 "use gnulib module mathl for portability");
168 # if !@HAVE_ATANL@ || !@HAVE_DECL_ATANL@
169 _GL_FUNCDECL_SYS (atanl, long double, (long double x));
171 _GL_CXXALIAS_SYS (atanl, long double, (long double x));
172 _GL_CXXALIASWARN (atanl);
173 #elif defined GNULIB_POSIXCHECK
175 # if HAVE_RAW_DECL_ATANL
176 _GL_WARN_ON_USE (atanl, "atanl is unportable - "
177 "use gnulib module mathl for portability");
184 # if !(defined __cplusplus && defined GNULIB_NAMESPACE)
185 # define ceilf rpl_ceilf
187 _GL_FUNCDECL_RPL (ceilf, float, (float x));
188 _GL_CXXALIAS_RPL (ceilf, float, (float x));
190 # if !@HAVE_DECL_CEILF@
191 _GL_FUNCDECL_SYS (ceilf, float, (float x));
193 _GL_CXXALIAS_SYS (ceilf, float, (float x));
195 _GL_CXXALIASWARN (ceilf);
196 #elif defined GNULIB_POSIXCHECK
198 # if HAVE_RAW_DECL_CEILF
199 _GL_WARN_ON_USE (ceilf, "ceilf is unportable - "
200 "use gnulib module ceilf for portability");
206 # if !(defined __cplusplus && defined GNULIB_NAMESPACE)
207 # define ceill rpl_ceill
209 _GL_FUNCDECL_RPL (ceill, long double, (long double x));
210 _GL_CXXALIAS_RPL (ceill, long double, (long double x));
212 # if !@HAVE_DECL_CEILL@
213 _GL_FUNCDECL_SYS (ceill, long double, (long double x));
215 _GL_CXXALIAS_SYS (ceill, long double, (long double x));
217 _GL_CXXALIASWARN (ceill);
218 #elif defined GNULIB_POSIXCHECK
220 # if HAVE_RAW_DECL_CEILL
221 _GL_WARN_ON_USE (ceill, "ceill is unportable - "
222 "use gnulib module ceill for portability");
228 # if !@HAVE_COSL@ || !@HAVE_DECL_COSL@
229 _GL_FUNCDECL_SYS (cosl, long double, (long double x));
231 _GL_CXXALIAS_SYS (cosl, long double, (long double x));
232 _GL_CXXALIASWARN (cosl);
233 #elif defined GNULIB_POSIXCHECK
235 # if HAVE_RAW_DECL_COSL
236 _GL_WARN_ON_USE (cosl, "cosl is unportable - "
237 "use gnulib module mathl for portability");
243 # if !@HAVE_EXPL@ || !@HAVE_DECL_EXPL@
244 _GL_FUNCDECL_SYS (expl, long double, (long double x));
246 _GL_CXXALIAS_SYS (expl, long double, (long double x));
247 _GL_CXXALIASWARN (expl);
248 #elif defined GNULIB_POSIXCHECK
250 # if HAVE_RAW_DECL_EXPL
251 _GL_WARN_ON_USE (expl, "expl is unportable - "
252 "use gnulib module mathl for portability");
258 # if @REPLACE_FLOORF@
259 # if !(defined __cplusplus && defined GNULIB_NAMESPACE)
260 # define floorf rpl_floorf
262 _GL_FUNCDECL_RPL (floorf, float, (float x));
263 _GL_CXXALIAS_RPL (floorf, float, (float x));
265 # if !@HAVE_DECL_FLOORF@
266 _GL_FUNCDECL_SYS (floorf, float, (float x));
268 _GL_CXXALIAS_SYS (floorf, float, (float x));
270 _GL_CXXALIASWARN (floorf);
271 #elif defined GNULIB_POSIXCHECK
273 # if HAVE_RAW_DECL_FLOORF
274 _GL_WARN_ON_USE (floorf, "floorf is unportable - "
275 "use gnulib module floorf for portability");
280 # if @REPLACE_FLOORL@
281 # if !(defined __cplusplus && defined GNULIB_NAMESPACE)
282 # define floorl rpl_floorl
284 _GL_FUNCDECL_RPL (floorl, long double, (long double x));
285 _GL_CXXALIAS_RPL (floorl, long double, (long double x));
287 # if !@HAVE_DECL_FLOORL@
288 _GL_FUNCDECL_SYS (floorl, long double, (long double x));
290 _GL_CXXALIAS_SYS (floorl, long double, (long double x));
292 _GL_CXXALIASWARN (floorl);
293 #elif defined GNULIB_POSIXCHECK
295 # if HAVE_RAW_DECL_FLOORL
296 _GL_WARN_ON_USE (floorl, "floorl is unportable - "
297 "use gnulib module floorl for portability");
305 If x finite and nonzero: 0.5 <= |mantissa| < 1.0.
306 If x is zero: mantissa = x, exp = 0.
307 If x is infinite or NaN: mantissa = x, exp unspecified.
308 Store exp in *EXPPTR and return mantissa. */
309 #if @GNULIB_FREXPL@ && @REPLACE_FREXPL@
310 # if !(defined __cplusplus && defined GNULIB_NAMESPACE)
311 # define frexpl rpl_frexpl
313 _GL_FUNCDECL_RPL (frexpl, long double,
314 (long double x, int *expptr) _GL_ARG_NONNULL ((2)));
315 _GL_CXXALIAS_RPL (frexpl, long double, (long double x, int *expptr));
317 # if !@HAVE_DECL_FREXPL@
318 _GL_FUNCDECL_SYS (frexpl, long double,
319 (long double x, int *expptr) _GL_ARG_NONNULL ((2)));
322 _GL_CXXALIAS_SYS (frexpl, long double, (long double x, int *expptr));
325 #if @GNULIB_FREXPL@ && !(@REPLACE_FREXPL@ && !@HAVE_DECL_FREXPL@)
326 _GL_CXXALIASWARN (frexpl);
328 #if !@GNULIB_FREXPL@ && defined GNULIB_POSIXCHECK
330 # if HAVE_RAW_DECL_FREXPL
331 _GL_WARN_ON_USE (frexpl, "frexpl is unportable - "
332 "use gnulib module frexpl for portability");
337 /* Return x * 2^exp. */
338 #if @GNULIB_LDEXPL@ && @REPLACE_LDEXPL@
339 # if !(defined __cplusplus && defined GNULIB_NAMESPACE)
340 # define ldexpl rpl_ldexpl
342 _GL_FUNCDECL_RPL (ldexpl, long double, (long double x, int exp));
343 _GL_CXXALIAS_RPL (ldexpl, long double, (long double x, int exp));
345 # if !@HAVE_DECL_LDEXPL@
346 _GL_FUNCDECL_SYS (ldexpl, long double, (long double x, int exp));
349 _GL_CXXALIAS_SYS (ldexpl, long double, (long double x, int exp));
353 _GL_CXXALIASWARN (ldexpl);
355 #if !@GNULIB_LDEXPL@ && defined GNULIB_POSIXCHECK
357 # if HAVE_RAW_DECL_LDEXPL
358 _GL_WARN_ON_USE (ldexpl, "ldexpl is unportable - "
359 "use gnulib module ldexpl for portability");
365 # if !@HAVE_LOGL@ || !@HAVE_DECL_LOGL@
366 _GL_FUNCDECL_SYS (logl, long double, (long double x));
368 _GL_CXXALIAS_SYS (logl, long double, (long double x));
369 _GL_CXXALIASWARN (logl);
370 #elif defined GNULIB_POSIXCHECK
372 # if HAVE_RAW_DECL_LOGL
373 _GL_WARN_ON_USE (logl, "logl is unportable - "
374 "use gnulib module mathl for portability");
380 # if @REPLACE_ROUNDF@
381 # if !(defined __cplusplus && defined GNULIB_NAMESPACE)
383 # define roundf rpl_roundf
385 _GL_FUNCDECL_RPL (roundf, float, (float x));
386 _GL_CXXALIAS_RPL (roundf, float, (float x));
388 # if !@HAVE_DECL_ROUNDF@
389 _GL_FUNCDECL_SYS (roundf, float, (float x));
391 _GL_CXXALIAS_SYS (roundf, float, (float x));
393 _GL_CXXALIASWARN (roundf);
394 #elif defined GNULIB_POSIXCHECK
396 # if HAVE_RAW_DECL_ROUNDF
397 _GL_WARN_ON_USE (roundf, "roundf is unportable - "
398 "use gnulib module roundf for portability");
404 # if !(defined __cplusplus && defined GNULIB_NAMESPACE)
406 # define round rpl_round
408 _GL_FUNCDECL_RPL (round, double, (double x));
409 _GL_CXXALIAS_RPL (round, double, (double x));
411 # if !@HAVE_DECL_ROUND@
412 _GL_FUNCDECL_SYS (round, double, (double x));
414 _GL_CXXALIAS_SYS (round, double, (double x));
416 _GL_CXXALIASWARN (round);
417 #elif defined GNULIB_POSIXCHECK
419 # if HAVE_RAW_DECL_ROUND
420 _GL_WARN_ON_USE (round, "round is unportable - "
421 "use gnulib module round for portability");
426 # if @REPLACE_ROUNDL@
427 # if !(defined __cplusplus && defined GNULIB_NAMESPACE)
429 # define roundl rpl_roundl
431 _GL_FUNCDECL_RPL (roundl, long double, (long double x));
432 _GL_CXXALIAS_RPL (roundl, long double, (long double x));
434 # if !@HAVE_DECL_ROUNDL@
435 _GL_FUNCDECL_SYS (roundl, long double, (long double x));
437 _GL_CXXALIAS_SYS (roundl, long double, (long double x));
439 _GL_CXXALIASWARN (roundl);
440 #elif defined GNULIB_POSIXCHECK
442 # if HAVE_RAW_DECL_ROUNDL
443 _GL_WARN_ON_USE (roundl, "roundl is unportable - "
444 "use gnulib module roundl for portability");
450 # if !@HAVE_SINL@ || !@HAVE_DECL_SINL@
451 _GL_FUNCDECL_SYS (sinl, long double, (long double x));
453 _GL_CXXALIAS_SYS (sinl, long double, (long double x));
454 _GL_CXXALIASWARN (sinl);
455 #elif defined GNULIB_POSIXCHECK
457 # if HAVE_RAW_DECL_SINL
458 _GL_WARN_ON_USE (sinl, "sinl is unportable - "
459 "use gnulib module mathl for portability");
465 # if !@HAVE_SQRTL@ || !@HAVE_DECL_SQRTL@
466 _GL_FUNCDECL_SYS (sqrtl, long double, (long double x));
468 _GL_CXXALIAS_SYS (sqrtl, long double, (long double x));
469 _GL_CXXALIASWARN (sqrtl);
470 #elif defined GNULIB_POSIXCHECK
472 # if HAVE_RAW_DECL_SQRTL
473 _GL_WARN_ON_USE (sqrtl, "sqrtl is unportable - "
474 "use gnulib module mathl for portability");
480 # if !@HAVE_TANL@ || !@HAVE_DECL_TANL@
481 _GL_FUNCDECL_SYS (tanl, long double, (long double x));
483 _GL_CXXALIAS_SYS (tanl, long double, (long double x));
484 _GL_CXXALIASWARN (tanl);
485 #elif defined GNULIB_POSIXCHECK
487 # if HAVE_RAW_DECL_TANL
488 _GL_WARN_ON_USE (tanl, "tanl is unportable - "
489 "use gnulib module mathl for portability");
495 # if !@HAVE_DECL_TRUNCF@
496 _GL_FUNCDECL_SYS (truncf, float, (float x));
498 _GL_CXXALIAS_SYS (truncf, float, (float x));
499 _GL_CXXALIASWARN (truncf);
500 #elif defined GNULIB_POSIXCHECK
502 # if HAVE_RAW_DECL_TRUNCF
503 _GL_WARN_ON_USE (truncf, "truncf is unportable - "
504 "use gnulib module truncf for portability");
509 # if !@HAVE_DECL_TRUNC@
510 _GL_FUNCDECL_SYS (trunc, double, (double x));
512 _GL_CXXALIAS_SYS (trunc, double, (double x));
513 _GL_CXXALIASWARN (trunc);
514 #elif defined GNULIB_POSIXCHECK
516 # if HAVE_RAW_DECL_TRUNC
517 _GL_WARN_ON_USE (trunc, "trunc is unportable - "
518 "use gnulib module trunc for portability");
523 # if @REPLACE_TRUNCL@
524 # if !(defined __cplusplus && defined GNULIB_NAMESPACE)
526 # define truncl rpl_truncl
528 _GL_FUNCDECL_RPL (truncl, long double, (long double x));
529 _GL_CXXALIAS_RPL (truncl, long double, (long double x));
531 # if !@HAVE_DECL_TRUNCL@
532 _GL_FUNCDECL_SYS (truncl, long double, (long double x));
534 _GL_CXXALIAS_SYS (truncl, long double, (long double x));
536 _GL_CXXALIASWARN (truncl);
537 #elif defined GNULIB_POSIXCHECK
539 # if HAVE_RAW_DECL_TRUNCL
540 _GL_WARN_ON_USE (truncl, "truncl is unportable - "
541 "use gnulib module truncl for portability");
546 #if @GNULIB_ISFINITE@
547 # if @REPLACE_ISFINITE@
548 _GL_EXTERN_C int gl_isfinitef (float x);
549 _GL_EXTERN_C int gl_isfinited (double x);
550 _GL_EXTERN_C int gl_isfinitel (long double x);
552 # define isfinite(x) \
553 (sizeof (x) == sizeof (long double) ? gl_isfinitel (x) : \
554 sizeof (x) == sizeof (double) ? gl_isfinited (x) : \
557 #elif defined GNULIB_POSIXCHECK
558 # if defined isfinite
559 _GL_WARN_REAL_FLOATING_DECL (isfinite);
561 # define isfinite(x) _GL_WARN_REAL_FLOATING_IMPL (isfinite, x)
568 _GL_EXTERN_C int gl_isinff (float x);
569 _GL_EXTERN_C int gl_isinfd (double x);
570 _GL_EXTERN_C int gl_isinfl (long double x);
573 (sizeof (x) == sizeof (long double) ? gl_isinfl (x) : \
574 sizeof (x) == sizeof (double) ? gl_isinfd (x) : \
577 #elif defined GNULIB_POSIXCHECK
579 _GL_WARN_REAL_FLOATING_DECL (isinf);
581 # define isinf(x) _GL_WARN_REAL_FLOATING_IMPL (isinf, x)
587 /* Test for NaN for 'float' numbers. */
589 /* The original <math.h> included above provides a declaration of isnan macro
590 or (older) isnanf function. */
592 /* GCC 4.0 and newer provides three built-ins for isnan. */
594 # define isnanf(x) __builtin_isnanf ((float)(x))
597 # define isnanf(x) isnan ((float)(x))
600 /* Test whether X is a NaN. */
602 # define isnanf rpl_isnanf
603 _GL_EXTERN_C int isnanf (float x);
608 /* Test for NaN for 'double' numbers.
609 This function is a gnulib extension, unlike isnan() which applied only
610 to 'double' numbers earlier but now is a type-generic macro. */
612 /* The original <math.h> included above provides a declaration of isnan macro. */
614 /* GCC 4.0 and newer provides three built-ins for isnan. */
616 # define isnand(x) __builtin_isnan ((double)(x))
619 # define isnand(x) isnan ((double)(x))
622 /* Test whether X is a NaN. */
624 # define isnand rpl_isnand
625 _GL_EXTERN_C int isnand (double x);
630 /* Test for NaN for 'long double' numbers. */
632 /* The original <math.h> included above provides a declaration of isnan macro or (older) isnanl function. */
634 /* GCC 4.0 and newer provides three built-ins for isnan. */
636 # define isnanl(x) __builtin_isnanl ((long double)(x))
639 # define isnanl(x) isnan ((long double)(x))
642 /* Test whether X is a NaN. */
644 # define isnanl rpl_isnanl
645 _GL_EXTERN_C int isnanl (long double x);
649 /* This must come *after* the snippets for GNULIB_ISNANF and GNULIB_ISNANL! */
652 /* We can't just use the isnanf macro (e.g.) as exposed by
653 isnanf.h (e.g.) here, because those may end up being macros
654 that recursively expand back to isnan. So use the gnulib
655 replacements for them directly. */
656 # if @HAVE_ISNANF@ && __GNUC__ >= 4
657 # define gl_isnan_f(x) __builtin_isnan ((float)(x))
659 _GL_EXTERN_C int rpl_isnanf (float x);
660 # define gl_isnan_f(x) rpl_isnanf (x)
662 # if @HAVE_ISNAND@ && __GNUC__ >= 4
663 # define gl_isnan_d(x) __builtin_isnan ((double)(x))
665 _GL_EXTERN_C int rpl_isnand (double x);
666 # define gl_isnan_d(x) rpl_isnand (x)
668 # if @HAVE_ISNANL@ && __GNUC__ >= 4
669 # define gl_isnan_l(x) __builtin_isnan ((long double)(x))
671 _GL_EXTERN_C int rpl_isnanl (long double x);
672 # define gl_isnan_l(x) rpl_isnanl (x)
676 (sizeof (x) == sizeof (long double) ? gl_isnan_l (x) : \
677 sizeof (x) == sizeof (double) ? gl_isnan_d (x) : \
680 #elif defined GNULIB_POSIXCHECK
682 _GL_WARN_REAL_FLOATING_DECL (isnan);
684 # define isnan(x) _GL_WARN_REAL_FLOATING_IMPL (isnan, x)
690 # if @REPLACE_SIGNBIT_USING_GCC@
692 /* GCC 4.0 and newer provides three built-ins for signbit. */
693 # define signbit(x) \
694 (sizeof (x) == sizeof (long double) ? __builtin_signbitl (x) : \
695 sizeof (x) == sizeof (double) ? __builtin_signbit (x) : \
696 __builtin_signbitf (x))
698 # if @REPLACE_SIGNBIT@
700 _GL_EXTERN_C int gl_signbitf (float arg);
701 _GL_EXTERN_C int gl_signbitd (double arg);
702 _GL_EXTERN_C int gl_signbitl (long double arg);
703 # if __GNUC__ >= 2 && !__STRICT_ANSI__
704 # if defined FLT_SIGNBIT_WORD && defined FLT_SIGNBIT_BIT && !defined gl_signbitf
705 # define gl_signbitf_OPTIMIZED_MACRO
706 # define gl_signbitf(arg) \
707 ({ union { float _value; \
708 unsigned int _word[(sizeof (float) + sizeof (unsigned int) - 1) / sizeof (unsigned int)]; \
711 (_m._word[FLT_SIGNBIT_WORD] >> FLT_SIGNBIT_BIT) & 1; \
714 # if defined DBL_SIGNBIT_WORD && defined DBL_SIGNBIT_BIT && !defined gl_signbitd
715 # define gl_signbitd_OPTIMIZED_MACRO
716 # define gl_signbitd(arg) \
717 ({ union { double _value; \
718 unsigned int _word[(sizeof (double) + sizeof (unsigned int) - 1) / sizeof (unsigned int)]; \
721 (_m._word[DBL_SIGNBIT_WORD] >> DBL_SIGNBIT_BIT) & 1; \
724 # if defined LDBL_SIGNBIT_WORD && defined LDBL_SIGNBIT_BIT && !defined gl_signbitl
725 # define gl_signbitl_OPTIMIZED_MACRO
726 # define gl_signbitl(arg) \
727 ({ union { long double _value; \
728 unsigned int _word[(sizeof (long double) + sizeof (unsigned int) - 1) / sizeof (unsigned int)]; \
731 (_m._word[LDBL_SIGNBIT_WORD] >> LDBL_SIGNBIT_BIT) & 1; \
735 # define signbit(x) \
736 (sizeof (x) == sizeof (long double) ? gl_signbitl (x) : \
737 sizeof (x) == sizeof (double) ? gl_signbitd (x) : \
740 #elif defined GNULIB_POSIXCHECK
742 _GL_WARN_REAL_FLOATING_DECL (signbit);
744 # define signbit(x) _GL_WARN_REAL_FLOATING_IMPL (signbit, x)
749 #endif /* _GL_MATH_H */
750 #endif /* _GL_MATH_H */