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@
25 /* The include_next requires a split double-inclusion guard. */
26 #@INCLUDE_NEXT_AS_FIRST_DIRECTIVE@ @NEXT_AS_FIRST_DIRECTIVE_MATH_H@
32 /* The definitions of _GL_FUNCDECL_RPL etc. are copied here. */
34 /* The definition of _GL_ARG_NONNULL is copied here. */
36 /* The definition of _GL_WARN_ON_USE is copied here. */
38 /* Helper macros to define a portability warning for the
39 classification macro FUNC called with VALUE. POSIX declares the
40 classification macros with an argument of real-floating (that is,
41 one of float, double, or long double). */
42 #define _GL_WARN_REAL_FLOATING_DECL(func) \
44 rpl_ ## func ## f (float f) \
49 rpl_ ## func ## d (double d) \
54 rpl_ ## func ## l (long double l) \
58 _GL_WARN_ON_USE (rpl_ ## func ## f, #func " is unportable - " \
59 "use gnulib module " #func " for portability"); \
60 _GL_WARN_ON_USE (rpl_ ## func ## d, #func " is unportable - " \
61 "use gnulib module " #func " for portability"); \
62 _GL_WARN_ON_USE (rpl_ ## func ## l, #func " is unportable - " \
63 "use gnulib module " #func " for portability")
64 #define _GL_WARN_REAL_FLOATING_IMPL(func, value) \
65 (sizeof (value) == sizeof (float) ? rpl_ ## func ## f (value) \
66 : sizeof (value) == sizeof (double) ? rpl_ ## func ## d (value) \
67 : rpl_ ## func ## l (value))
70 /* POSIX allows platforms that don't support NAN. But all major
71 machines in the past 15 years have supported something close to
72 IEEE NaN, so we define this unconditionally. We also must define
73 it on platforms like Solaris 10, where NAN is present but defined
74 as a function pointer rather than a floating point constant. */
75 #if !defined NAN || @REPLACE_NAN@
77 /* The Compaq (ex-DEC) C 6.4 compiler chokes on the expression 0.0 / 0.0. */
82 static float zero = 0.0f;
87 # define NAN (0.0f / 0.0f)
91 /* Solaris 10 defines HUGE_VAL, but as a function pointer rather
92 than a floating point constant. */
93 #if @REPLACE_HUGE_VAL@
95 # define HUGE_VAL (1.0 / 0.0)
102 If x finite and nonzero: 0.5 <= |mantissa| < 1.0.
103 If x is zero: mantissa = x, exp = 0.
104 If x is infinite or NaN: mantissa = x, exp unspecified.
105 Store exp in *EXPPTR and return mantissa. */
108 # if !(defined __cplusplus && defined GNULIB_NAMESPACE)
109 # define frexp rpl_frexp
111 _GL_FUNCDECL_RPL (frexp, double, (double x, int *expptr) _GL_ARG_NONNULL ((2)));
112 _GL_CXXALIAS_RPL (frexp, double, (double x, int *expptr));
114 _GL_CXXALIAS_SYS (frexp, double, (double x, int *expptr));
116 _GL_CXXALIASWARN (frexp);
117 #elif defined GNULIB_POSIXCHECK
119 /* Assume frexp is always declared. */
120 _GL_WARN_ON_USE (frexp, "frexp is unportable - "
121 "use gnulib module frexp for portability");
126 # if !@HAVE_DECL_LOGB@
127 _GL_EXTERN_C double logb (double x);
129 #elif defined GNULIB_POSIXCHECK
131 # if HAVE_RAW_DECL_LOGB
132 _GL_WARN_ON_USE (logb, "logb is unportable - "
133 "use gnulib module logb for portability");
139 # if !@HAVE_ACOSL@ || !@HAVE_DECL_ACOSL@
140 _GL_FUNCDECL_SYS (acosl, long double, (long double x));
142 _GL_CXXALIAS_SYS (acosl, long double, (long double x));
143 _GL_CXXALIASWARN (acosl);
144 #elif defined GNULIB_POSIXCHECK
146 # if HAVE_RAW_DECL_ACOSL
147 _GL_WARN_ON_USE (acosl, "acosl is unportable - "
148 "use gnulib module mathl for portability");
154 # if !@HAVE_ASINL@ || !@HAVE_DECL_ASINL@
155 _GL_FUNCDECL_SYS (asinl, long double, (long double x));
157 _GL_CXXALIAS_SYS (asinl, long double, (long double x));
158 _GL_CXXALIASWARN (asinl);
159 #elif defined GNULIB_POSIXCHECK
161 # if HAVE_RAW_DECL_ASINL
162 _GL_WARN_ON_USE (asinl, "asinl is unportable - "
163 "use gnulib module mathl for portability");
169 # if !@HAVE_ATANL@ || !@HAVE_DECL_ATANL@
170 _GL_FUNCDECL_SYS (atanl, long double, (long double x));
172 _GL_CXXALIAS_SYS (atanl, long double, (long double x));
173 _GL_CXXALIASWARN (atanl);
174 #elif defined GNULIB_POSIXCHECK
176 # if HAVE_RAW_DECL_ATANL
177 _GL_WARN_ON_USE (atanl, "atanl is unportable - "
178 "use gnulib module mathl for portability");
185 # if !(defined __cplusplus && defined GNULIB_NAMESPACE)
186 # define ceilf rpl_ceilf
188 _GL_FUNCDECL_RPL (ceilf, float, (float x));
189 _GL_CXXALIAS_RPL (ceilf, float, (float x));
191 # if !@HAVE_DECL_CEILF@
192 _GL_FUNCDECL_SYS (ceilf, float, (float x));
194 _GL_CXXALIAS_SYS (ceilf, float, (float x));
196 _GL_CXXALIASWARN (ceilf);
197 #elif defined GNULIB_POSIXCHECK
199 # if HAVE_RAW_DECL_CEILF
200 _GL_WARN_ON_USE (ceilf, "ceilf is unportable - "
201 "use gnulib module ceilf for portability");
207 # if !(defined __cplusplus && defined GNULIB_NAMESPACE)
208 # define ceill rpl_ceill
210 _GL_FUNCDECL_RPL (ceill, long double, (long double x));
211 _GL_CXXALIAS_RPL (ceill, long double, (long double x));
213 # if !@HAVE_DECL_CEILL@
214 _GL_FUNCDECL_SYS (ceill, long double, (long double x));
216 _GL_CXXALIAS_SYS (ceill, long double, (long double x));
218 _GL_CXXALIASWARN (ceill);
219 #elif defined GNULIB_POSIXCHECK
221 # if HAVE_RAW_DECL_CEILL
222 _GL_WARN_ON_USE (ceill, "ceill is unportable - "
223 "use gnulib module ceill for portability");
229 # if !@HAVE_COSL@ || !@HAVE_DECL_COSL@
230 _GL_FUNCDECL_SYS (cosl, long double, (long double x));
232 _GL_CXXALIAS_SYS (cosl, long double, (long double x));
233 _GL_CXXALIASWARN (cosl);
234 #elif defined GNULIB_POSIXCHECK
236 # if HAVE_RAW_DECL_COSL
237 _GL_WARN_ON_USE (cosl, "cosl is unportable - "
238 "use gnulib module mathl for portability");
244 # if !@HAVE_EXPL@ || !@HAVE_DECL_EXPL@
245 _GL_FUNCDECL_SYS (expl, long double, (long double x));
247 _GL_CXXALIAS_SYS (expl, long double, (long double x));
248 _GL_CXXALIASWARN (expl);
249 #elif defined GNULIB_POSIXCHECK
251 # if HAVE_RAW_DECL_EXPL
252 _GL_WARN_ON_USE (expl, "expl is unportable - "
253 "use gnulib module mathl for portability");
259 # if @REPLACE_FLOORF@
260 # if !(defined __cplusplus && defined GNULIB_NAMESPACE)
261 # define floorf rpl_floorf
263 _GL_FUNCDECL_RPL (floorf, float, (float x));
264 _GL_CXXALIAS_RPL (floorf, float, (float x));
266 # if !@HAVE_DECL_FLOORF@
267 _GL_FUNCDECL_SYS (floorf, float, (float x));
269 _GL_CXXALIAS_SYS (floorf, float, (float x));
271 _GL_CXXALIASWARN (floorf);
272 #elif defined GNULIB_POSIXCHECK
274 # if HAVE_RAW_DECL_FLOORF
275 _GL_WARN_ON_USE (floorf, "floorf is unportable - "
276 "use gnulib module floorf for portability");
281 # if @REPLACE_FLOORL@
282 # if !(defined __cplusplus && defined GNULIB_NAMESPACE)
283 # define floorl rpl_floorl
285 _GL_FUNCDECL_RPL (floorl, long double, (long double x));
286 _GL_CXXALIAS_RPL (floorl, long double, (long double x));
288 # if !@HAVE_DECL_FLOORL@
289 _GL_FUNCDECL_SYS (floorl, long double, (long double x));
291 _GL_CXXALIAS_SYS (floorl, long double, (long double x));
293 _GL_CXXALIASWARN (floorl);
294 #elif defined GNULIB_POSIXCHECK
296 # if HAVE_RAW_DECL_FLOORL
297 _GL_WARN_ON_USE (floorl, "floorl is unportable - "
298 "use gnulib module floorl for portability");
306 If x finite and nonzero: 0.5 <= |mantissa| < 1.0.
307 If x is zero: mantissa = x, exp = 0.
308 If x is infinite or NaN: mantissa = x, exp unspecified.
309 Store exp in *EXPPTR and return mantissa. */
310 #if @GNULIB_FREXPL@ && @REPLACE_FREXPL@
311 # if !(defined __cplusplus && defined GNULIB_NAMESPACE)
312 # define frexpl rpl_frexpl
314 _GL_FUNCDECL_RPL (frexpl, long double,
315 (long double x, int *expptr) _GL_ARG_NONNULL ((2)));
316 _GL_CXXALIAS_RPL (frexpl, long double, (long double x, int *expptr));
318 # if !@HAVE_DECL_FREXPL@
319 _GL_FUNCDECL_SYS (frexpl, long double,
320 (long double x, int *expptr) _GL_ARG_NONNULL ((2)));
323 _GL_CXXALIAS_SYS (frexpl, long double, (long double x, int *expptr));
326 #if @GNULIB_FREXPL@ && !(@REPLACE_FREXPL@ && !@HAVE_DECL_FREXPL@)
327 _GL_CXXALIASWARN (frexpl);
329 #if !@GNULIB_FREXPL@ && defined GNULIB_POSIXCHECK
331 # if HAVE_RAW_DECL_FREXPL
332 _GL_WARN_ON_USE (frexpl, "frexpl is unportable - "
333 "use gnulib module frexpl for portability");
338 /* Return x * 2^exp. */
339 #if @GNULIB_LDEXPL@ && @REPLACE_LDEXPL@
340 # if !(defined __cplusplus && defined GNULIB_NAMESPACE)
341 # define ldexpl rpl_ldexpl
343 _GL_FUNCDECL_RPL (ldexpl, long double, (long double x, int exp));
344 _GL_CXXALIAS_RPL (ldexpl, long double, (long double x, int exp));
346 # if !@HAVE_DECL_LDEXPL@
347 _GL_FUNCDECL_SYS (ldexpl, long double, (long double x, int exp));
350 _GL_CXXALIAS_SYS (ldexpl, long double, (long double x, int exp));
354 _GL_CXXALIASWARN (ldexpl);
356 #if !@GNULIB_LDEXPL@ && defined GNULIB_POSIXCHECK
358 # if HAVE_RAW_DECL_LDEXPL
359 _GL_WARN_ON_USE (ldexpl, "ldexpl is unportable - "
360 "use gnulib module ldexpl for portability");
366 # if !@HAVE_LOGL@ || !@HAVE_DECL_LOGL@
367 _GL_FUNCDECL_SYS (logl, long double, (long double x));
369 _GL_CXXALIAS_SYS (logl, long double, (long double x));
370 _GL_CXXALIASWARN (logl);
371 #elif defined GNULIB_POSIXCHECK
373 # if HAVE_RAW_DECL_LOGL
374 _GL_WARN_ON_USE (logl, "logl is unportable - "
375 "use gnulib module mathl for portability");
381 # if @REPLACE_ROUNDF@
382 # if !(defined __cplusplus && defined GNULIB_NAMESPACE)
384 # define roundf rpl_roundf
386 _GL_FUNCDECL_RPL (roundf, float, (float x));
387 _GL_CXXALIAS_RPL (roundf, float, (float x));
389 # if !@HAVE_DECL_ROUNDF@
390 _GL_FUNCDECL_SYS (roundf, float, (float x));
392 _GL_CXXALIAS_SYS (roundf, float, (float x));
394 _GL_CXXALIASWARN (roundf);
395 #elif defined GNULIB_POSIXCHECK
397 # if HAVE_RAW_DECL_ROUNDF
398 _GL_WARN_ON_USE (roundf, "roundf is unportable - "
399 "use gnulib module roundf for portability");
405 # if !(defined __cplusplus && defined GNULIB_NAMESPACE)
407 # define round rpl_round
409 _GL_FUNCDECL_RPL (round, double, (double x));
410 _GL_CXXALIAS_RPL (round, double, (double x));
412 # if !@HAVE_DECL_ROUND@
413 _GL_FUNCDECL_SYS (round, double, (double x));
415 _GL_CXXALIAS_SYS (round, double, (double x));
417 _GL_CXXALIASWARN (round);
418 #elif defined GNULIB_POSIXCHECK
420 # if HAVE_RAW_DECL_ROUND
421 _GL_WARN_ON_USE (round, "round is unportable - "
422 "use gnulib module round for portability");
427 # if @REPLACE_ROUNDL@
428 # if !(defined __cplusplus && defined GNULIB_NAMESPACE)
430 # define roundl rpl_roundl
432 _GL_FUNCDECL_RPL (roundl, long double, (long double x));
433 _GL_CXXALIAS_RPL (roundl, long double, (long double x));
435 # if !@HAVE_DECL_ROUNDL@
436 _GL_FUNCDECL_SYS (roundl, long double, (long double x));
438 _GL_CXXALIAS_SYS (roundl, long double, (long double x));
440 _GL_CXXALIASWARN (roundl);
441 #elif defined GNULIB_POSIXCHECK
443 # if HAVE_RAW_DECL_ROUNDL
444 _GL_WARN_ON_USE (roundl, "roundl is unportable - "
445 "use gnulib module roundl for portability");
451 # if !@HAVE_SINL@ || !@HAVE_DECL_SINL@
452 _GL_FUNCDECL_SYS (sinl, long double, (long double x));
454 _GL_CXXALIAS_SYS (sinl, long double, (long double x));
455 _GL_CXXALIASWARN (sinl);
456 #elif defined GNULIB_POSIXCHECK
458 # if HAVE_RAW_DECL_SINL
459 _GL_WARN_ON_USE (sinl, "sinl is unportable - "
460 "use gnulib module mathl for portability");
466 # if !@HAVE_SQRTL@ || !@HAVE_DECL_SQRTL@
467 _GL_FUNCDECL_SYS (sqrtl, long double, (long double x));
469 _GL_CXXALIAS_SYS (sqrtl, long double, (long double x));
470 _GL_CXXALIASWARN (sqrtl);
471 #elif defined GNULIB_POSIXCHECK
473 # if HAVE_RAW_DECL_SQRTL
474 _GL_WARN_ON_USE (sqrtl, "sqrtl is unportable - "
475 "use gnulib module mathl for portability");
481 # if !@HAVE_TANL@ || !@HAVE_DECL_TANL@
482 _GL_FUNCDECL_SYS (tanl, long double, (long double x));
484 _GL_CXXALIAS_SYS (tanl, long double, (long double x));
485 _GL_CXXALIASWARN (tanl);
486 #elif defined GNULIB_POSIXCHECK
488 # if HAVE_RAW_DECL_TANL
489 _GL_WARN_ON_USE (tanl, "tanl is unportable - "
490 "use gnulib module mathl for portability");
496 # if @REPLACE_TRUNCF@
497 # if !(defined __cplusplus && defined GNULIB_NAMESPACE)
498 # define truncf rpl_truncf
500 _GL_FUNCDECL_RPL (truncf, float, (float x));
501 _GL_CXXALIAS_RPL (truncf, float, (float x));
503 # if !@HAVE_DECL_TRUNCF@
504 _GL_FUNCDECL_SYS (truncf, float, (float x));
506 _GL_CXXALIAS_SYS (truncf, float, (float x));
508 _GL_CXXALIASWARN (truncf);
509 #elif defined GNULIB_POSIXCHECK
511 # if HAVE_RAW_DECL_TRUNCF
512 _GL_WARN_ON_USE (truncf, "truncf is unportable - "
513 "use gnulib module truncf for portability");
518 # if !@HAVE_DECL_TRUNC@
519 _GL_FUNCDECL_SYS (trunc, double, (double x));
521 _GL_CXXALIAS_SYS (trunc, double, (double x));
522 _GL_CXXALIASWARN (trunc);
523 #elif defined GNULIB_POSIXCHECK
525 # if HAVE_RAW_DECL_TRUNC
526 _GL_WARN_ON_USE (trunc, "trunc is unportable - "
527 "use gnulib module trunc for portability");
532 # if @REPLACE_TRUNCL@
533 # if !(defined __cplusplus && defined GNULIB_NAMESPACE)
535 # define truncl rpl_truncl
537 _GL_FUNCDECL_RPL (truncl, long double, (long double x));
538 _GL_CXXALIAS_RPL (truncl, long double, (long double x));
540 # if !@HAVE_DECL_TRUNCL@
541 _GL_FUNCDECL_SYS (truncl, long double, (long double x));
543 _GL_CXXALIAS_SYS (truncl, long double, (long double x));
545 _GL_CXXALIASWARN (truncl);
546 #elif defined GNULIB_POSIXCHECK
548 # if HAVE_RAW_DECL_TRUNCL
549 _GL_WARN_ON_USE (truncl, "truncl is unportable - "
550 "use gnulib module truncl for portability");
555 #if @GNULIB_ISFINITE@
556 # if @REPLACE_ISFINITE@
557 _GL_EXTERN_C int gl_isfinitef (float x);
558 _GL_EXTERN_C int gl_isfinited (double x);
559 _GL_EXTERN_C int gl_isfinitel (long double x);
561 # define isfinite(x) \
562 (sizeof (x) == sizeof (long double) ? gl_isfinitel (x) : \
563 sizeof (x) == sizeof (double) ? gl_isfinited (x) : \
566 #elif defined GNULIB_POSIXCHECK
567 # if defined isfinite
568 _GL_WARN_REAL_FLOATING_DECL (isfinite);
570 # define isfinite(x) _GL_WARN_REAL_FLOATING_IMPL (isfinite, x)
577 _GL_EXTERN_C int gl_isinff (float x);
578 _GL_EXTERN_C int gl_isinfd (double x);
579 _GL_EXTERN_C int gl_isinfl (long double x);
582 (sizeof (x) == sizeof (long double) ? gl_isinfl (x) : \
583 sizeof (x) == sizeof (double) ? gl_isinfd (x) : \
586 #elif defined GNULIB_POSIXCHECK
588 _GL_WARN_REAL_FLOATING_DECL (isinf);
590 # define isinf(x) _GL_WARN_REAL_FLOATING_IMPL (isinf, x)
596 /* Test for NaN for 'float' numbers. */
598 /* The original <math.h> included above provides a declaration of isnan macro
599 or (older) isnanf function. */
601 /* GCC 4.0 and newer provides three built-ins for isnan. */
603 # define isnanf(x) __builtin_isnanf ((float)(x))
606 # define isnanf(x) isnan ((float)(x))
609 /* Test whether X is a NaN. */
611 # define isnanf rpl_isnanf
612 _GL_EXTERN_C int isnanf (float x);
617 /* Test for NaN for 'double' numbers.
618 This function is a gnulib extension, unlike isnan() which applied only
619 to 'double' numbers earlier but now is a type-generic macro. */
621 /* The original <math.h> included above provides a declaration of isnan
624 /* GCC 4.0 and newer provides three built-ins for isnan. */
626 # define isnand(x) __builtin_isnan ((double)(x))
629 # define isnand(x) isnan ((double)(x))
632 /* Test whether X is a NaN. */
634 # define isnand rpl_isnand
635 _GL_EXTERN_C int isnand (double x);
640 /* Test for NaN for 'long double' numbers. */
642 /* The original <math.h> included above provides a declaration of isnan
643 macro or (older) isnanl function. */
645 /* GCC 4.0 and newer provides three built-ins for isnan. */
647 # define isnanl(x) __builtin_isnanl ((long double)(x))
650 # define isnanl(x) isnan ((long double)(x))
653 /* Test whether X is a NaN. */
655 # define isnanl rpl_isnanl
656 _GL_EXTERN_C int isnanl (long double x);
660 /* This must come *after* the snippets for GNULIB_ISNANF and GNULIB_ISNANL! */
663 /* We can't just use the isnanf macro (e.g.) as exposed by
664 isnanf.h (e.g.) here, because those may end up being macros
665 that recursively expand back to isnan. So use the gnulib
666 replacements for them directly. */
667 # if @HAVE_ISNANF@ && __GNUC__ >= 4
668 # define gl_isnan_f(x) __builtin_isnan ((float)(x))
670 _GL_EXTERN_C int rpl_isnanf (float x);
671 # define gl_isnan_f(x) rpl_isnanf (x)
673 # if @HAVE_ISNAND@ && __GNUC__ >= 4
674 # define gl_isnan_d(x) __builtin_isnan ((double)(x))
676 _GL_EXTERN_C int rpl_isnand (double x);
677 # define gl_isnan_d(x) rpl_isnand (x)
679 # if @HAVE_ISNANL@ && __GNUC__ >= 4
680 # define gl_isnan_l(x) __builtin_isnan ((long double)(x))
682 _GL_EXTERN_C int rpl_isnanl (long double x);
683 # define gl_isnan_l(x) rpl_isnanl (x)
687 (sizeof (x) == sizeof (long double) ? gl_isnan_l (x) : \
688 sizeof (x) == sizeof (double) ? gl_isnan_d (x) : \
691 /* Ensure isnan is a macro. */
695 #elif defined GNULIB_POSIXCHECK
697 _GL_WARN_REAL_FLOATING_DECL (isnan);
699 # define isnan(x) _GL_WARN_REAL_FLOATING_IMPL (isnan, x)
705 # if @REPLACE_SIGNBIT_USING_GCC@
707 /* GCC 4.0 and newer provides three built-ins for signbit. */
708 # define signbit(x) \
709 (sizeof (x) == sizeof (long double) ? __builtin_signbitl (x) : \
710 sizeof (x) == sizeof (double) ? __builtin_signbit (x) : \
711 __builtin_signbitf (x))
713 # if @REPLACE_SIGNBIT@
715 _GL_EXTERN_C int gl_signbitf (float arg);
716 _GL_EXTERN_C int gl_signbitd (double arg);
717 _GL_EXTERN_C int gl_signbitl (long double arg);
718 # if __GNUC__ >= 2 && !__STRICT_ANSI__
719 # define _GL_NUM_UINT_WORDS(type) \
720 ((sizeof (type) + sizeof (unsigned int) - 1) / sizeof (unsigned int))
721 # if defined FLT_SIGNBIT_WORD && defined FLT_SIGNBIT_BIT && !defined gl_signbitf
722 # define gl_signbitf_OPTIMIZED_MACRO
723 # define gl_signbitf(arg) \
724 ({ union { float _value; \
725 unsigned int _word[_GL_NUM_UINT_WORDS (float)]; \
728 (_m._word[FLT_SIGNBIT_WORD] >> FLT_SIGNBIT_BIT) & 1; \
731 # if defined DBL_SIGNBIT_WORD && defined DBL_SIGNBIT_BIT && !defined gl_signbitd
732 # define gl_signbitd_OPTIMIZED_MACRO
733 # define gl_signbitd(arg) \
734 ({ union { double _value; \
735 unsigned int _word[_GL_NUM_UINT_WORDS (double)]; \
738 (_m._word[DBL_SIGNBIT_WORD] >> DBL_SIGNBIT_BIT) & 1; \
741 # if defined LDBL_SIGNBIT_WORD && defined LDBL_SIGNBIT_BIT && !defined gl_signbitl
742 # define gl_signbitl_OPTIMIZED_MACRO
743 # define gl_signbitl(arg) \
744 ({ union { long double _value; \
745 unsigned int _word[_GL_NUM_UINT_WORDS (long double)]; \
748 (_m._word[LDBL_SIGNBIT_WORD] >> LDBL_SIGNBIT_BIT) & 1; \
752 # define signbit(x) \
753 (sizeof (x) == sizeof (long double) ? gl_signbitl (x) : \
754 sizeof (x) == sizeof (double) ? gl_signbitd (x) : \
757 #elif defined GNULIB_POSIXCHECK
759 _GL_WARN_REAL_FLOATING_DECL (signbit);
761 # define signbit(x) _GL_WARN_REAL_FLOATING_IMPL (signbit, x)
766 #endif /* _GL_MATH_H */
767 #endif /* _GL_MATH_H */