summaryrefslogtreecommitdiff
path: root/acinclude.m4
blob: d542154f191ccb83cc196c9bc65647790a1bc0ee (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
dnl  MPFR specific autoconf macros

dnl  Copyright 2000, 2002-2016 Free Software Foundation, Inc.
dnl  Contributed by the AriC and Caramba projects, INRIA.
dnl
dnl  This file is part of the GNU MPFR Library.
dnl
dnl  The GNU MPFR Library is free software; you can redistribute it and/or modify
dnl  it under the terms of the GNU Lesser General Public License as published
dnl  by the Free Software Foundation; either version 3 of the License, or (at
dnl  your option) any later version.
dnl
dnl  The GNU MPFR Library is distributed in the hope that it will be useful, but
dnl  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
dnl  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
dnl  License for more details.
dnl
dnl  You should have received a copy of the GNU Lesser General Public License
dnl  along with the GNU MPFR Library; see the file COPYING.LESSER.  If not, see
dnl  http://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc.,
dnl  51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.

dnl  autoconf 2.60 is necessary because of the use of AC_PROG_SED.
dnl  The following line allows the autoconf wrapper (when installed)
dnl  to work as expected.
dnl  If you change the required version, please update README.dev too!
AC_PREREQ(2.60)

dnl ------------------------------------------------------------
dnl You must put in MPFR_CONFIGS everything which configure MPFR
dnl except:
dnl   - Everything dealing with CC and CFLAGS in particular the ABI
dnl     but the IEEE-754 specific flags must be set here.
dnl   - Tests that depend on gmp.h (see MPFR_CHECK_DBL2INT_BUG as an example:
dnl     a function needs to be defined and called in configure.ac).
dnl   - GMP's linkage.
dnl   - Libtool stuff.
dnl   - Handling of special arguments of MPFR's configure.
AC_DEFUN([MPFR_CONFIGS],
[
AC_REQUIRE([AC_OBJEXT])
AC_REQUIRE([MPFR_CHECK_LIBM])
AC_REQUIRE([MPFR_CHECK_LIBQUADMATH])
AC_REQUIRE([AC_HEADER_TIME])
AC_REQUIRE([AC_CANONICAL_HOST])

AC_CHECK_HEADER([limits.h],, AC_MSG_ERROR([limits.h not found]))
AC_CHECK_HEADER([float.h],,  AC_MSG_ERROR([float.h not found]))
AC_CHECK_HEADER([string.h],, AC_MSG_ERROR([string.h not found]))

dnl Check for locales
AC_CHECK_HEADERS([locale.h])

dnl Check for wide characters (wchar_t and wint_t)
AC_CHECK_HEADERS([wchar.h])

dnl Check for stdargs
AC_CHECK_HEADER([stdarg.h],[AC_DEFINE([HAVE_STDARG],1,[Define if stdarg])],
  [AC_CHECK_HEADER([varargs.h],,
    AC_MSG_ERROR([stdarg.h or varargs.h not found]))])

dnl sys/fpu.h - MIPS specific
AC_CHECK_HEADERS([sys/time.h sys/fpu.h])

dnl Android has a <locale.h>, but not the following members.
AC_CHECK_MEMBERS([struct lconv.decimal_point, struct lconv.thousands_sep],,,
  [#include <locale.h>])

dnl Check how to get `alloca'
AC_FUNC_ALLOCA

dnl SIZE_MAX macro
gl_SIZE_MAX

dnl va_copy macro
AC_MSG_CHECKING([how to copy va_list])
AC_LINK_IFELSE([AC_LANG_PROGRAM([[
#include <stdarg.h>
]], [[
   va_list ap1, ap2;
   va_copy(ap1, ap2);
]])], [
   AC_MSG_RESULT([va_copy])
   AC_DEFINE(HAVE_VA_COPY)
], [AC_LINK_IFELSE([AC_LANG_PROGRAM([[
#include <stdarg.h>
]], [[
   va_list ap1, ap2;
   __va_copy(ap1, ap2);
]])], [AC_DEFINE([HAVE___VA_COPY]) AC_MSG_RESULT([__va_copy])],
   [AC_MSG_RESULT([memcpy])])])

dnl FIXME: The functions memmove, memset and strtol are really needed by
dnl MPFR, but if they are implemented as macros, this is also OK (in our
dnl case).  So, we do not return an error, but their tests are currently
dnl useless.
dnl Moreover, for memmove and memset, when gcc -Werror is used, these
dnl functions are considered to be missing because of a "conflicting
dnl types for built-in function" error. Possible workarounds if the
dnl results of this test are used (thus one doesn't want an error):
dnl   * If "$GCC" is set, disable built-ins by adding -fno-builtin
dnl     to $CFLAGS for this test (this would yield a failure if such
dnl     functions are defined only as built-ins, but does this occur
dnl     in practice?).
dnl   * Enable -Werror only for the main compilation (and possibly
dnl     some particular tests) via a new configure option.
dnl gettimeofday is not defined for MinGW
AC_CHECK_FUNCS([memmove memset setlocale strtol gettimeofday signal])

dnl We cannot use AC_CHECK_FUNCS on sigaction, because while this
dnl function may be provided by the C library, its prototype and
dnl associated structure may not be available, e.g. when compiling
dnl with "gcc -std=c99".
AC_MSG_CHECKING(for sigaction and its associated structure)
AC_LINK_IFELSE([AC_LANG_PROGRAM([[
#include <signal.h>
static int f (int (*func)(int, const struct sigaction *, struct sigaction *))
{ return 0; }
]], [[
 return f(sigaction);
]])], [
   AC_MSG_RESULT(yes)
   AC_DEFINE(HAVE_SIGACTION, 1,
    [Define if you have a working sigaction function.])
],[AC_MSG_RESULT(no)])

dnl Check for IEEE-754 switches on Alpha
case $host in
alpha*-*-*)
  saved_CFLAGS="$CFLAGS"
  AC_CACHE_CHECK([for IEEE-754 switches], mpfr_cv_ieee_switches, [
  if test -n "$GCC"; then
    mpfr_cv_ieee_switches="-mfp-rounding-mode=d -mieee-with-inexact"
  else
    mpfr_cv_ieee_switches="-fprm d -ieee_with_inexact"
  fi
  CFLAGS="$CFLAGS $mpfr_cv_ieee_switches"
  AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[]])], , mpfr_cv_ieee_switches="none")
  ])
  if test "$mpfr_cv_ieee_switches" = "none"; then
    CFLAGS="$saved_CFLAGS"
  else
    CFLAGS="$saved_CFLAGS $mpfr_cv_ieee_switches"
  fi
esac

dnl check for long long
AC_CHECK_TYPE([long long int],
   AC_DEFINE(HAVE_LONG_LONG, 1, [Define if compiler supports long long]),,)

dnl intmax_t is C99
AC_CHECK_TYPES([intmax_t])
if test "$ac_cv_type_intmax_t" = yes; then
  AC_CACHE_CHECK([for working INTMAX_MAX], mpfr_cv_have_intmax_max, [
    saved_CPPFLAGS="$CPPFLAGS"
    CPPFLAGS="$CPPFLAGS -I$srcdir/src"
    AC_COMPILE_IFELSE([AC_LANG_PROGRAM(
        [[#include "mpfr-intmax.h"]],
        [[intmax_t x = INTMAX_MAX; (void) x;]]
      )],
      mpfr_cv_have_intmax_max=yes, mpfr_cv_have_intmax_max=no)
    CPPFLAGS="$saved_CPPFLAGS"
  ])
  if test "$mpfr_cv_have_intmax_max" = "yes"; then
    AC_DEFINE(MPFR_HAVE_INTMAX_MAX,1,[Define if you have a working INTMAX_MAX.])
  fi
  AC_CACHE_CHECK([for working printf length modifier for intmax_t],
                 mpfr_cv_printf_maxlm, [
    saved_CPPFLAGS="$CPPFLAGS"
    CPPFLAGS="$CPPFLAGS -I$srcdir/src"
    for modifier in j ll l
    do
      AC_RUN_IFELSE([AC_LANG_PROGRAM([[
#include <stdio.h>
#include <string.h>
#include "mpfr-intmax.h"
]],[[
  char s[64];
  sprintf (s, "%${modifier}d %${modifier}u",
           (intmax_t) -17, (uintmax_t) 42);
  return strcmp (s, "-17 42") != 0;
]])],
       mpfr_cv_printf_maxlm=${modifier}; break,
       mpfr_cv_printf_maxlm=none,
dnl We assume that j is working when cross-compiling.
       mpfr_cv_printf_maxlm=j; break
      )
    done
    CPPFLAGS="$saved_CPPFLAGS"
  ])
  if test "$mpfr_cv_printf_maxlm" != "none"; then
    AC_DEFINE_UNQUOTED([MPFR_PRINTF_MAXLM],["$mpfr_cv_printf_maxlm"],
      [Define to a working printf length modifier for intmax_t])
  fi
fi

AC_CHECK_TYPE( [union fpc_csr],
   AC_DEFINE(HAVE_FPC_CSR,1,[Define if union fpc_csr is available]), ,
[
#if HAVE_SYS_FPU_H
#  include <sys/fpu.h>
#endif
])

dnl Check for _Noreturn function specifier (ISO C11)
AC_CACHE_CHECK([for _Noreturn], mpfr_cv_have_noreturn, [
  AC_COMPILE_IFELSE([AC_LANG_SOURCE([[_Noreturn void foo(int);]])],
    mpfr_cv_have_noreturn=yes, mpfr_cv_have_noreturn=no)
])
if test "$mpfr_cv_have_noreturn" = "yes"; then
  AC_DEFINE(MPFR_HAVE_NORETURN,1,[Define if the _Noreturn function specifier is supported.])
fi

dnl Check for __builtin_unreachable
AC_CACHE_CHECK([for __builtin_unreachable], mpfr_cv_have_builtin_unreachable,
[
  AC_LINK_IFELSE([AC_LANG_PROGRAM(
      [[int x;]],
      [[if (x) __builtin_unreachable(); ]]
    )],
    mpfr_cv_have_builtin_unreachable=yes,
    mpfr_cv_have_builtin_unreachable=no)
])
if test "$mpfr_cv_have_builtin_unreachable" = "yes"; then
  AC_DEFINE(MPFR_HAVE_BUILTIN_UNREACHABLE, 1,
   [Define if the __builtin_unreachable GCC built-in is supported.])
fi

dnl Check for fesetround
AC_CACHE_CHECK([for fesetround], mpfr_cv_have_fesetround, [
saved_LIBS="$LIBS"
LIBS="$LIBS $MPFR_LIBM"
AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <fenv.h>]], [[fesetround(FE_TONEAREST);]])],
  mpfr_cv_have_fesetround=yes, mpfr_cv_have_fesetround=no)
LIBS="$saved_LIBS"
])
if test "$mpfr_cv_have_fesetround" = "yes"; then
  AC_DEFINE(MPFR_HAVE_FESETROUND,1,[Define if you have the `fesetround' function via the <fenv.h> header file.])
fi

dnl Check for gcc float-conversion bug; if need be, -ffloat-store is used to
dnl force the conversion to the destination type when a value is stored to
dnl a variable (see ISO C99 standard 5.1.2.3#13, 6.3.1.5#2, 6.3.1.8#2). This
dnl is important concerning the exponent range. Note that this doesn't solve
dnl the double-rounding problem.
if test -n "$GCC"; then
  AC_CACHE_CHECK([for gcc float-conversion bug], mpfr_cv_gcc_floatconv_bug, [
  saved_LIBS="$LIBS"
  LIBS="$LIBS $MPFR_LIBM"
  AC_RUN_IFELSE([AC_LANG_SOURCE([[
#include <float.h>
#ifdef MPFR_HAVE_FESETROUND
#include <fenv.h>
#endif
static double get_max (void);
int main (void) {
  double x = 0.5;
  double y;
  int i;
  for (i = 1; i <= 11; i++)
    x *= x;
  if (x != 0)
    return 1;
#ifdef MPFR_HAVE_FESETROUND
  /* Useful test for the G4 PowerPC */
  fesetround(FE_TOWARDZERO);
  x = y = get_max ();
  x *= 2.0;
  if (x != y)
    return 1;
#endif
  return 0;
}
static double get_max (void) { static volatile double d = DBL_MAX; return d; }
  ]])],
     [mpfr_cv_gcc_floatconv_bug="no"],
     [mpfr_cv_gcc_floatconv_bug="yes, use -ffloat-store"],
     [mpfr_cv_gcc_floatconv_bug="cannot test, use -ffloat-store"])
  LIBS="$saved_LIBS"
  ])
  if test "$mpfr_cv_gcc_floatconv_bug" != "no"; then
    CFLAGS="$CFLAGS -ffloat-store"
  fi
fi

dnl Check if subnormal (denormalized) numbers are supported
AC_CACHE_CHECK([for subnormal numbers], mpfr_cv_have_denorms, [
AC_RUN_IFELSE([AC_LANG_SOURCE([[
#include <stdio.h>
int main (void) {
  double x = 2.22507385850720138309e-308;
  fprintf (stderr, "%e\n", x / 2.0);
  return 2.0 * (x / 2.0) != x;
}
]])],
   [mpfr_cv_have_denorms="yes"],
   [mpfr_cv_have_denorms="no"],
   [mpfr_cv_have_denorms="cannot test, assume no"])
])
if test "$mpfr_cv_have_denorms" = "yes"; then
  AC_DEFINE(HAVE_DENORMS,1,[Define if subnormal (denormalized) floats work.])
fi

dnl Check if signed zeros are supported. Note: the test will fail
dnl if the division by 0 generates a trap.
AC_CACHE_CHECK([for signed zeros], mpfr_cv_have_signedz, [
AC_RUN_IFELSE([AC_LANG_SOURCE([[
int main (void) {
  return 1.0 / 0.0 == 1.0 / -0.0;
}
]])],
   [mpfr_cv_have_signedz="yes"],
   [mpfr_cv_have_signedz="no"],
   [mpfr_cv_have_signedz="cannot test, assume no"])
])
if test "$mpfr_cv_have_signedz" = "yes"; then
  AC_DEFINE(HAVE_SIGNEDZ,1,[Define if signed zeros are supported.])
fi

dnl Check the FP division by 0 fails (e.g. on a non-IEEE-754 platform).
dnl In such a case, MPFR_ERRDIVZERO is defined to disable the tests
dnl involving a FP division by 0.
dnl For the developers: to check whether all these tests are disabled,
dnl configure MPFR with "-DMPFR_TESTS_DIVBYZERO -DMPFR_ERRDIVZERO".
AC_CACHE_CHECK([if the FP division by 0 fails], mpfr_cv_errdivzero, [
AC_RUN_IFELSE([AC_LANG_SOURCE([[
int main (void) {
  volatile double d = 0.0, x;
  x = 0.0 / d;
  x = 1.0 / d;
  (void) x;
  return 0;
}
]])],
   [mpfr_cv_errdivzero="no"],
   [mpfr_cv_errdivzero="yes"],
   [mpfr_cv_errdivzero="cannot test, assume no"])
])
if test "$mpfr_cv_errdivzero" = "yes"; then
  AC_DEFINE(MPFR_ERRDIVZERO,1,[Define if the FP division by 0 fails.])
  AC_MSG_WARN([The floating-point division by 0 fails instead of])
  AC_MSG_WARN([returning a special value: NaN or infinity. Tests])
  AC_MSG_WARN([involving a FP division by 0 will be disabled.])
fi

dnl Check whether NAN != NAN (as required by the IEEE-754 standard,
dnl but not by the ISO C standard). For instance, this is false with
dnl MIPSpro 7.3.1.3m under IRIX64. By default, assume this is true.
AC_CACHE_CHECK([if NAN == NAN], mpfr_cv_nanisnan, [
AC_RUN_IFELSE([AC_LANG_SOURCE([[
#include <stdio.h>
#include <math.h>
#ifndef NAN
# define NAN (0.0/0.0)
#endif
int main (void) {
  double d;
  d = NAN;
  return d != d;
}
]])],
   [mpfr_cv_nanisnan="yes"],
   [mpfr_cv_nanisnan="no"],
   [mpfr_cv_nanisnan="cannot test, assume no"])
])
if test "$mpfr_cv_nanisnan" = "yes"; then
  AC_DEFINE(MPFR_NANISNAN,1,[Define if NAN == NAN.])
  AC_MSG_WARN([The test NAN != NAN is false. The probable reason is that])
  AC_MSG_WARN([your compiler optimizes floating-point expressions in an])
  AC_MSG_WARN([unsafe way because some option, such as -ffast-math or])
  AC_MSG_WARN([-fast (depending on the compiler), has been used.  You])
  AC_MSG_WARN([should NOT use such an option, otherwise MPFR functions])
  AC_MSG_WARN([such as mpfr_get_d and mpfr_set_d may return incorrect])
  AC_MSG_WARN([results on special FP numbers (e.g. NaN or signed zeros).])
  AC_MSG_WARN([If you did not use such an option, please send us a bug])
  AC_MSG_WARN([report so that we can try to find a workaround for your])
  AC_MSG_WARN([platform and/or document the behavior.])
fi

dnl Check if the chars '0' to '9' are consecutive values
AC_MSG_CHECKING([if charset has consecutive values])
AC_RUN_IFELSE([AC_LANG_PROGRAM([[
char *number = "0123456789";
char *lower  = "abcdefghijklmnopqrstuvwxyz";
char *upper  = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
]],[[
 int i;
 unsigned char *p;
 for (p = (unsigned char*) number, i = 0; i < 9; i++)
   if ( (*p)+1 != *(p+1) ) return 1;
 for (p = (unsigned char*) lower, i = 0; i < 25; i++)
   if ( (*p)+1 != *(p+1) ) return 1;
 for (p = (unsigned char*) upper, i = 0; i < 25; i++)
   if ( (*p)+1 != *(p+1) ) return 1;
]])], [AC_MSG_RESULT(yes)],[
 AC_MSG_RESULT(no)
 AC_DEFINE(MPFR_NO_CONSECUTIVE_CHARSET,1,[Charset is not consecutive])
], [AC_MSG_RESULT(cannot test)])

dnl Must be checked with the LIBM
dnl but we don't want to add the LIBM to MPFR dependency.
dnl Can't use AC_CHECK_FUNCS since the function may be in LIBM but
dnl not exported in math.h
saved_LIBS="$LIBS"
LIBS="$LIBS $MPFR_LIBM"
dnl AC_CHECK_FUNCS([round trunc floor ceil nearbyint])
AC_MSG_CHECKING(for math/round)
AC_LINK_IFELSE([AC_LANG_PROGRAM([[
#include <math.h>
static int f (double (*func)(double)) { return 0; }
]], [[
 return f(round);
]])], [
   AC_MSG_RESULT(yes)
   AC_DEFINE(HAVE_ROUND, 1,[Have ISO C99 round function])
],[AC_MSG_RESULT(no)])

AC_MSG_CHECKING(for math/trunc)
AC_LINK_IFELSE([AC_LANG_PROGRAM([[
#include <math.h>
static int f (double (*func)(double)) { return 0; }
]], [[
 return f(trunc);
]])], [
   AC_MSG_RESULT(yes)
   AC_DEFINE(HAVE_TRUNC, 1,[Have ISO C99 trunc function])
],[AC_MSG_RESULT(no)])

AC_MSG_CHECKING(for math/floor)
AC_LINK_IFELSE([AC_LANG_PROGRAM([[
#include <math.h>
static int f (double (*func)(double)) { return 0; }
]], [[
 return f(floor);
]])], [
   AC_MSG_RESULT(yes)
   AC_DEFINE(HAVE_FLOOR, 1,[Have ISO C99 floor function])
],[AC_MSG_RESULT(no)])

AC_MSG_CHECKING(for math/ceil)
AC_LINK_IFELSE([AC_LANG_PROGRAM([[
#include <math.h>
static int f (double (*func)(double)) { return 0; }
]], [[
 return f(ceil);
]])], [
   AC_MSG_RESULT(yes)
   AC_DEFINE(HAVE_CEIL, 1,[Have ISO C99 ceil function])
],[AC_MSG_RESULT(no)])

AC_MSG_CHECKING(for math/nearbyint)
AC_LINK_IFELSE([AC_LANG_PROGRAM([[
#include <math.h>
static int f (double (*func)(double)) { return 0; }
]], [[
 return f(nearbyint);
]])], [
   AC_MSG_RESULT(yes)
   AC_DEFINE(HAVE_NEARBYINT, 1,[Have ISO C99 nearbyint function])
],[AC_MSG_RESULT(no)])

LIBS="$saved_LIBS"

dnl Now try to check the long double format
MPFR_C_LONG_DOUBLE_FORMAT

if test "$enable_logging" = yes; then
  if test "$enable_thread_safe" = yes; then
    AC_MSG_ERROR([Enable either `Logging' or `thread-safe', not both])
  else
    enable_thread_safe=no
  fi
fi

dnl Check if thread-local variables are supported.
dnl At least two problems can occur in practice:
dnl 1. The compilation fails, e.g. because the compiler doesn't know
dnl    about the __thread keyword.
dnl 2. The compilation succeeds, but the system doesn't support TLS or
dnl    there is some ld configuration problem. One of the effects can
dnl    be that thread-local variables always evaluate to 0. So, it is
dnl    important to run the test below.
if test "$enable_thread_safe" != no; then
AC_MSG_CHECKING(for TLS support using C11)
saved_CPPFLAGS="$CPPFLAGS"
CPPFLAGS="$CPPFLAGS -I$srcdir/src"
AC_RUN_IFELSE([AC_LANG_SOURCE([[
#define MPFR_USE_THREAD_SAFE 1
#define MPFR_USE_C11_THREAD_SAFE 1
#include "mpfr-thread.h"
MPFR_THREAD_ATTR int x = 17;
int main (void) {
  return x != 17;
}
  ]])],
     [AC_MSG_RESULT(yes)
      AC_DEFINE([MPFR_USE_THREAD_SAFE],1,[Build MPFR as thread safe])
      AC_DEFINE([MPFR_USE_C11_THREAD_SAFE],1,[Build MPFR as thread safe using C11])
      tls_c11_support=yes
     ],
     [AC_MSG_RESULT(no)
     ],
     [AC_MSG_RESULT([cannot test, assume no])
     ])
CPPFLAGS="$saved_CPPFLAGS"

if test "$tls_c11_support" != "yes"
then

 AC_MSG_CHECKING(for TLS support)
 saved_CPPFLAGS="$CPPFLAGS"
 CPPFLAGS="$CPPFLAGS -I$srcdir/src"
 AC_RUN_IFELSE([AC_LANG_SOURCE([[
 #define MPFR_USE_THREAD_SAFE 1
 #include "mpfr-thread.h"
 MPFR_THREAD_ATTR int x = 17;
 int main (void) {
   return x != 17;
 }
   ]])],
      [AC_MSG_RESULT(yes)
       AC_DEFINE([MPFR_USE_THREAD_SAFE],1,[Build MPFR as thread safe])
      ],
      [AC_MSG_RESULT(no)
       if test "$enable_thread_safe" = yes; then
         AC_MSG_ERROR([please configure with --disable-thread-safe])
       fi
      ],
      [if test "$enable_thread_safe" = yes; then
         AC_MSG_RESULT([cannot test, assume yes])
         AC_DEFINE([MPFR_USE_THREAD_SAFE],1,[Build MPFR as thread safe])
       else
         AC_MSG_RESULT([cannot test, assume no])
       fi
      ])
 CPPFLAGS="$saved_CPPFLAGS"
 fi
fi

dnl Check if Static Assertions are supported.
AC_MSG_CHECKING(for Static Assertion support)
saved_CPPFLAGS="$CPPFLAGS"
CPPFLAGS="$CPPFLAGS -I$srcdir/src"
AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
#define MPFR_USE_STATIC_ASSERT 1
#include "mpfr-sassert.h"

/* Test if Static Assertions work */
MPFR_DECL_STATIC_ASSERT(sizeof(char) <= sizeof(int));

int main (void) {
  MPFR_DECL_STATIC_ASSERT(sizeof(int) <= sizeof(long));
  int x;
  (void) (x = 1);  /* cast to void: avoid a warning, at least with GCC */
  /* Test of the macro after a declaraction and a statement. */
  MPFR_STAT_STATIC_ASSERT(sizeof(short) <= sizeof(int));
  return 0;
}
  ]])],
     [AC_MSG_RESULT(yes)
      AC_DEFINE([MPFR_USE_STATIC_ASSERT],1,[Build MPFR with Static Assertions])
     ],
     [AC_MSG_RESULT(no)
     ],
     [AC_MSG_RESULT([cannot test, assume no])
     ])
CPPFLAGS="$saved_CPPFLAGS"

])
dnl end of MPFR_CONFIGS


dnl MPFR_CHECK_GMP
dnl --------------
dnl Check GMP library vs header. Useful if the user provides --with-gmp
dnl with a directory containing a GMP version that doesn't have the
dnl correct ABI: the previous tests won't trigger the error if the same
dnl GMP version with the right ABI is installed on the system, as this
dnl library is automatically selected by the linker, while the header
dnl (which depends on the ABI) of the --with-gmp include directory is
dnl used.
dnl Note: if the error is changed to a warning due to that fact that
dnl libtool is not used, then the same thing should be done for the
dnl other tests based on GMP.
AC_DEFUN([MPFR_CHECK_GMP], [
AC_REQUIRE([MPFR_CONFIGS])dnl
AC_CACHE_CHECK([for GMP library vs header correctness], mpfr_cv_check_gmp, [
AC_RUN_IFELSE([AC_LANG_PROGRAM([[
#include <stdio.h>
#include <limits.h>
#include <gmp.h>
]], [[
  fprintf (stderr, "GMP_NAIL_BITS     = %d\n", (int) GMP_NAIL_BITS);
  fprintf (stderr, "GMP_NUMB_BITS     = %d\n", (int) GMP_NUMB_BITS);
  fprintf (stderr, "mp_bits_per_limb  = %d\n", (int) mp_bits_per_limb);
  fprintf (stderr, "sizeof(mp_limb_t) = %d\n", (int) sizeof(mp_limb_t));
  if (GMP_NAIL_BITS != 0)
    {
      fprintf (stderr, "GMP_NAIL_BITS != 0\n");
      return 1;
    }
  if (GMP_NUMB_BITS != mp_bits_per_limb)
    {
      fprintf (stderr, "GMP_NUMB_BITS != mp_bits_per_limb\n");
      return 2;
    }
  if (GMP_NUMB_BITS != sizeof(mp_limb_t) * CHAR_BIT)
    {
      fprintf (stderr, "GMP_NUMB_BITS != sizeof(mp_limb_t) * CHAR_BIT\n");
      return 3;
    }
  return 0;
]])], [mpfr_cv_check_gmp="yes"],
      [mpfr_cv_check_gmp="no (exit status is $?)"],
      [mpfr_cv_check_gmp="cannot test, assume yes"])
])
case $mpfr_cv_check_gmp in
no*)
  AC_MSG_ERROR([bad GMP library or header - ABI problem?
See 'config.log' for details.])
esac
])


dnl MPFR_CHECK_DBL2INT_BUG
dnl ----------------------
dnl Check for double-to-integer conversion bug
dnl https://gforge.inria.fr/tracker/index.php?func=detail&aid=14435
dnl For the exit status, the lowest values (including some values after 128)
dnl are reserved for various system errors. So, let's use the largest values
dnl below 255 for errors in the test itself.
dnl The following problem has been seen under Solaris in config.log,
dnl i.e. the failure to link with libgmp wasn't detected in the first
dnl test:
dnl   configure: checking if gmp.h version and libgmp version are the same
dnl   configure: gcc -o conftest -Wall -Wmissing-prototypes [...]
dnl   configure: $? = 0
dnl   configure: ./conftest
dnl   ld.so.1: conftest: fatal: libgmp.so.10: open failed: No such file [...]
dnl   configure: $? = 0
dnl   configure: result: yes
dnl   configure: checking for double-to-integer conversion bug
dnl   configure: gcc -o conftest -Wall -Wmissing-prototypes [...]
dnl   configure: $? = 0
dnl   configure: ./conftest
dnl   ld.so.1: conftest: fatal: libgmp.so.10: open failed: No such file [...]
dnl   ./configure[1680]: eval: line 1: 1971: Killed
dnl   configure: $? = 9
dnl   configure: program exited with status 9
AC_DEFUN([MPFR_CHECK_DBL2INT_BUG], [
AC_REQUIRE([MPFR_CONFIGS])dnl
AC_CACHE_CHECK([for double-to-integer conversion bug], mpfr_cv_dbl_int_bug, [
AC_RUN_IFELSE([AC_LANG_PROGRAM([[
#include <gmp.h>
]], [[
  double d;
  mp_limb_t u;
  int i;

  d = 1.0;
  for (i = 0; i < GMP_NUMB_BITS - 1; i++)
    d = d + d;
  u = (mp_limb_t) d;
  for (; i > 0; i--)
    {
      if (u & 1)
        break;
      u = u >> 1;
    }
  return (i == 0 && u == 1UL) ? 0 : 254 - i;
]])], [mpfr_cv_dbl_int_bug="no"],
      [mpfr_cv_dbl_int_bug="yes or failed to exec (exit status is $?)"],
      [mpfr_cv_dbl_int_bug="cannot test, assume not present"])
])
case $mpfr_cv_dbl_int_bug in
yes*)
  AC_MSG_ERROR([double-to-integer conversion is incorrect.
You need to use another compiler (or lower the optimization level).])
esac
])

dnl MPFR_CHECK_MP_LIMB_T_VS_LONG
dnl ----------------------------
dnl Check that a long can fit in a mp_limb_t.
dnl If so, it set the define MPFR_LONG_WITHIN_LIMB
AC_DEFUN([MPFR_CHECK_MP_LIMB_T_VS_LONG], [
AC_REQUIRE([MPFR_CONFIGS])
AC_CACHE_CHECK([for long to fit in mp_limb_t], mpfr_cv_long_within_limb, [
saved_CPPFLAGS="$CPPFLAGS"
CPPFLAGS="$CPPFLAGS -I$srcdir/src"
AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
#include <gmp.h>
#include "mpfr-sassert.h"
]], [[
  MPFR_STAT_STATIC_ASSERT ((mp_limb_t) -1 >= (unsigned long) -1);
  return 0;
]])], [mpfr_cv_long_within_limb="yes"],
      [mpfr_cv_long_within_limb="no"],
      [mpfr_cv_long_within_limb="cannot test, assume not present"])
])
case $mpfr_cv_long_within_limb in
yes*)
      AC_DEFINE([MPFR_LONG_WITHIN_LIMB],1,[long can be stored in mp_limb_t])
esac
CPPFLAGS="$saved_CPPFLAGS"
])

dnl MPFR_PARSE_DIRECTORY
dnl Input:  $1 = a string to a relative or absolute directory
dnl Output: $2 = the variable to set with the absolute directory
AC_DEFUN([MPFR_PARSE_DIRECTORY],
[
 dnl Check if argument is a directory
 if test -d $1 ; then
    dnl Get the absolute path of the directory
    dnl in case of relative directory.
    dnl If realpath is not a valid command,
    dnl an error is produced and we keep the given path.
    local_tmp=`realpath $1 2>/dev/null`
    if test "$local_tmp" != "" ; then
       if test -d "$local_tmp" ; then
           $2="$local_tmp"
       else
           $2=$1
       fi
    else
       $2=$1
    fi
    dnl Check for space in the directory
    if test `echo $1|cut -d' ' -f1` != $1 ; then
        AC_MSG_ERROR($1 directory shall not contain any space.)
    fi
 else
    AC_MSG_ERROR($1 shall be a valid directory)
 fi
])


dnl  MPFR_C_LONG_DOUBLE_FORMAT
dnl  -------------------------
dnl  Determine the format of a long double.
dnl
dnl  The object file is grepped, so as to work when cross compiling.  A
dnl  start and end sequence is included to avoid false matches, and
dnl  allowance is made for the desired data crossing an "od -b" line
dnl  boundary.  The test number is a small integer so it should appear
dnl  exactly, no rounding or truncation etc.
dnl
dnl  "od -b" is supported even by Unix V7, and the awk script used doesn't
dnl  have functions or anything, so even an "old" awk should suffice.
dnl
dnl  The 10-byte IEEE extended format is generally padded to either 12 or 16
dnl  bytes for alignment purposes.  The SVR4 i386 ABI is 12 bytes, or i386
dnl  gcc -m128bit-long-double selects 16 bytes.  IA-64 is 16 bytes in LP64
dnl  mode, or 12 bytes in ILP32 mode.  The first 10 bytes is the relevant
dnl  part in all cases (big and little endian).
dnl
dnl  Enhancements:
dnl
dnl  Could match more formats, but no need to worry until there's code
dnl  wanting to use them.
dnl
dnl  Don't want to duplicate the double matching from GMP_C_DOUBLE_FORMAT,
dnl  perhaps we should merge with that macro, to match data formats
dnl  irrespective of the C type in question.  Or perhaps just let the code
dnl  use DOUBLE macros when sizeof(double)==sizeof(long double).

AC_DEFUN([MPFR_C_LONG_DOUBLE_FORMAT],
[AC_REQUIRE([AC_PROG_CC])
AC_REQUIRE([AC_PROG_AWK])
AC_REQUIRE([AC_OBJEXT])
AC_CHECK_TYPES([long double])
AC_CACHE_CHECK([format of `long double' floating point],
                mpfr_cv_c_long_double_format,
[mpfr_cv_c_long_double_format=unknown
if test "$ac_cv_type_long_double" != yes; then
  mpfr_cv_c_long_double_format="not available"
else
  cat >conftest.c <<\EOF
[
/* "before" is 16 bytes to ensure there's no padding between it and "x".
   We're not expecting any "long double" bigger than 16 bytes or with
   alignment requirements stricter than 16 bytes.  */
struct {
  char         before[16];
  long double  x;
  char         after[8];
} foo = {
  { '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0',
    '\001', '\043', '\105', '\147', '\211', '\253', '\315', '\357' },
  -123456789.0,
  { '\376', '\334', '\272', '\230', '\166', '\124', '\062', '\020' }
};
]
EOF
  mpfr_compile="$CC $CFLAGS $CPPFLAGS -c conftest.c >&AS_MESSAGE_LOG_FD 2>&1"
  if AC_TRY_EVAL(mpfr_compile); then
    cat >conftest.awk <<\EOF
[
BEGIN {
  found = 0
}

# got[] holds a sliding window of bytes read the input.  got[0] is the most
# recent byte read, and got[31] the oldest byte read, so when looking to
# match some data the indices are "reversed".
#
{
  for (f = 2; f <= NF; f++)
    {
      # new byte, shift others up
      for (i = 31; i >= 0; i--)
        got[i+1] = got[i];
      got[0] = $f;

      # end sequence
      if (got[7] != "376") continue
      if (got[6] != "334") continue
      if (got[5] != "272") continue
      if (got[4] != "230") continue
      if (got[3] != "166") continue
      if (got[2] != "124") continue
      if (got[1] != "062") continue
      if (got[0] != "020") continue

      # start sequence, with 8-byte body
      if (got[23] == "001" && \
          got[22] == "043" && \
          got[21] == "105" && \
          got[20] == "147" && \
          got[19] == "211" && \
          got[18] == "253" && \
          got[17] == "315" && \
          got[16] == "357")
        {
          saw = " (" got[15] \
                 " " got[14] \
                 " " got[13] \
                 " " got[12] \
                 " " got[11] \
                 " " got[10] \
                 " " got[9]  \
                 " " got[8] ")"

          if (got[15] == "301" && \
              got[14] == "235" && \
              got[13] == "157" && \
              got[12] == "064" && \
              got[11] == "124" && \
              got[10] == "000" && \
              got[9] ==  "000" && \
              got[8] ==  "000")
            {
              print "IEEE double, big endian"
              found = 1
              exit
            }

          if (got[15] == "000" && \
              got[14] == "000" && \
              got[13] == "000" && \
              got[12] == "124" && \
              got[11] == "064" && \
              got[10] == "157" && \
              got[9] ==  "235" && \
              got[8] ==  "301")
            {
              print "IEEE double, little endian"
              found = 1
              exit
            }
        }

      # start sequence, with 12-byte body
      if (got[27] == "001" && \
          got[26] == "043" && \
          got[25] == "105" && \
          got[24] == "147" && \
          got[23] == "211" && \
          got[22] == "253" && \
          got[21] == "315" && \
          got[20] == "357")
        {
          saw = " (" got[19] \
                 " " got[18] \
                 " " got[17] \
                 " " got[16] \
                 " " got[15] \
                 " " got[14] \
                 " " got[13] \
                 " " got[12] \
                 " " got[11] \
                 " " got[10] \
                 " " got[9]  \
                 " " got[8] ")"

          if (got[19] == "000" && \
              got[18] == "000" && \
              got[17] == "000" && \
              got[16] == "000" && \
              got[15] == "240" && \
              got[14] == "242" && \
              got[13] == "171" && \
              got[12] == "353" && \
              got[11] == "031" && \
              got[10] == "300")
            {
              print "IEEE extended, little endian"
              found = 1
              exit
            }

          if (got[19] == "300" && \
              got[18] == "031" && \
              got[17] == "000" && \
              got[16] == "000" && \
              got[15] == "353" && \
              got[14] == "171" && \
              got[13] == "242" && \
              got[12] == "240" && \
              got[11] == "000" && \
              got[10] == "000" && \
              got[09] == "000" && \
              got[08] == "000")
            {
              # format found on m68k
              print "IEEE extended, big endian"
              found = 1
              exit
            }
        }

      # start sequence, with 16-byte body
      if (got[31] == "001" && \
          got[30] == "043" && \
          got[29] == "105" && \
          got[28] == "147" && \
          got[27] == "211" && \
          got[26] == "253" && \
          got[25] == "315" && \
          got[24] == "357")
        {
          saw = " (" got[23] \
                 " " got[22] \
                 " " got[21] \
                 " " got[20] \
                 " " got[19] \
                 " " got[18] \
                 " " got[17] \
                 " " got[16] \
                 " " got[15] \
                 " " got[14] \
                 " " got[13] \
                 " " got[12] \
                 " " got[11] \
                 " " got[10] \
                 " " got[9]  \
                 " " got[8] ")"

          if (got[23] == "000" && \
              got[22] == "000" && \
              got[21] == "000" && \
              got[20] == "000" && \
              got[19] == "240" && \
              got[18] == "242" && \
              got[17] == "171" && \
              got[16] == "353" && \
              got[15] == "031" && \
              got[14] == "300")
            {
              print "IEEE extended, little endian"
              found = 1
              exit
            }

          if (got[23] == "300" && \
              got[22] == "031" && \
              got[21] == "326" && \
              got[20] == "363" && \
              got[19] == "105" && \
              got[18] == "100" && \
              got[17] == "000" && \
              got[16] == "000" && \
              got[15] == "000" && \
              got[14] == "000" && \
              got[13] == "000" && \
              got[12] == "000" && \
              got[11] == "000" && \
              got[10] == "000" && \
              got[9]  == "000" && \
              got[8]  == "000")
            {
              # format used on HP 9000/785 under HP-UX
              print "IEEE quad, big endian"
              found = 1
              exit
            }

          if (got[23] == "000" && \
              got[22] == "000" && \
              got[21] == "000" && \
              got[20] == "000" && \
              got[19] == "000" && \
              got[18] == "000" && \
              got[17] == "000" && \
              got[16] == "000" && \
              got[15] == "000" && \
              got[14] == "000" && \
              got[13] == "100" && \
              got[12] == "105" && \
              got[11] == "363" && \
              got[10] == "326" && \
              got[9]  == "031" && \
	      got[8]  == "300")
            {
              print "IEEE quad, little endian"
              found = 1
              exit
            }

          if (got[23] == "301" && \
              got[22] == "235" && \
              got[21] == "157" && \
              got[20] == "064" && \
              got[19] == "124" && \
              got[18] == "000" && \
              got[17] == "000" && \
              got[16] == "000" && \
              got[15] == "000" && \
              got[14] == "000" && \
              got[13] == "000" && \
              got[12] == "000" && \
              got[11] == "000" && \
              got[10] == "000" && \
              got[9]  == "000" && \
              got[8]  == "000")
            {
              # format used on 32-bit PowerPC (Mac OS X and Debian GNU/Linux)
              print "possibly double-double, big endian"
              found = 1
              exit
            }

          if (got[23] == "000" && \
              got[22] == "000" && \
              got[21] == "000" && \
              got[20] == "124" && \
              got[19] == "064" && \
              got[18] == "157" && \
              got[17] == "235" && \
              got[16] == "301" && \
              got[15] == "000" && \
              got[14] == "000" && \
              got[13] == "000" && \
              got[12] == "000" && \
              got[11] == "000" && \
              got[10] == "000" && \
              got[9]  == "000" && \
              got[8]  == "000")
            {
              # format used on ppc64le
              print "possibly double-double, little endian"
              found = 1
              exit
            }
        }
    }
}

END {
  if (! found)
    print "unknown", saw
}
]
EOF
    mpfr_cv_c_long_double_format=`od -b conftest.$OBJEXT | $AWK -f conftest.awk`
    case $mpfr_cv_c_long_double_format in
    unknown*)
      echo "cannot match anything, conftest.$OBJEXT contains" >&AS_MESSAGE_LOG_FD
      od -b conftest.$OBJEXT >&AS_MESSAGE_LOG_FD
      ;;
    esac
  else
    AC_MSG_WARN([oops, cannot compile test program])
  fi
fi
rm -f conftest*
])

AH_VERBATIM([HAVE_LDOUBLE],
[/* Define one of the following to 1 for the format of a `long double'.
   If your format is not among these choices, or you don't know what it is,
   then leave all undefined.
   IEEE_EXT is the 10-byte IEEE extended precision format.
   IEEE_QUAD is the 16-byte IEEE quadruple precision format.
   LITTLE or BIG is the endianness.  */
#undef HAVE_LDOUBLE_IEEE_EXT_LITTLE
#undef HAVE_LDOUBLE_IEEE_QUAD_BIG])

case $mpfr_cv_c_long_double_format in
  "IEEE double, big endian")
    AC_DEFINE(HAVE_LDOUBLE_IS_DOUBLE, 1)
    ;;
  "IEEE double, little endian")
    AC_DEFINE(HAVE_LDOUBLE_IS_DOUBLE, 1)
    ;;
  "IEEE extended, little endian")
    AC_DEFINE(HAVE_LDOUBLE_IEEE_EXT_LITTLE, 1)
    ;;
  "IEEE extended, big endian")
    AC_DEFINE(HAVE_LDOUBLE_IEEE_EXT_BIG, 1)
    ;;
  "IEEE quad, big endian")
    AC_DEFINE(HAVE_LDOUBLE_IEEE_QUAD_BIG, 1)
    ;;
  "IEEE quad, little endian")
    AC_DEFINE(HAVE_LDOUBLE_IEEE_QUAD_LITTLE, 1)
    ;;
  "possibly double-double, big endian")
    AC_MSG_WARN([This format is known on GCC/PowerPC platforms,])
    AC_MSG_WARN([but due to GCC PR26374, we can't test further.])
    AC_MSG_WARN([You can safely ignore this warning, though.])
    AC_DEFINE(HAVE_LDOUBLE_MAYBE_DOUBLE_DOUBLE, 1)
    ;;
  "possibly double-double, little endian")
    AC_MSG_WARN([This format is known on GCC/PowerPC platforms,])
    AC_MSG_WARN([but due to GCC PR26374, we can't test further.])
    AC_MSG_WARN([You can safely ignore this warning, though.])
    AC_DEFINE(HAVE_LDOUBLE_MAYBE_DOUBLE_DOUBLE, 1)
    ;;
  unknown* | "not available")
    ;;
  *)
    AC_MSG_WARN([oops, unrecognised float format: $mpfr_cv_c_long_double_format])
    ;;
esac
])

dnl  MPFR_CHECK_LIBM
dnl  ---------------
dnl  Determine a math library -lm to use.

AC_DEFUN([MPFR_CHECK_LIBM],
[AC_REQUIRE([AC_CANONICAL_HOST])
AC_SUBST(MPFR_LIBM,'')
case $host in
  *-*-beos* | *-*-cygwin* | *-*-pw32*)
    # According to libtool AC CHECK LIBM, these systems don't have libm
    ;;
  *-*-solaris*)
    # On Solaris the math functions new in C99 are in -lm9x.
    # FIXME: Do we need -lm9x as well as -lm, or just instead of?
    AC_CHECK_LIB(m9x, main, MPFR_LIBM="-lm9x")
    AC_CHECK_LIB(m,   main, MPFR_LIBM="$MPFR_LIBM -lm")
    ;;
  *-ncr-sysv4.3*)
    # FIXME: What does -lmw mean?  Libtool AC CHECK LIBM does it this way.
    AC_CHECK_LIB(mw, _mwvalidcheckl, MPFR_LIBM="-lmw")
    AC_CHECK_LIB(m, main, MPFR_LIBM="$MPFR_LIBM -lm")
    ;;
  *)
    AC_CHECK_LIB(m, main, MPFR_LIBM="-lm")
    ;;
esac
])

dnl  MPFR_CHECK_LIBQUADMATH
dnl  ---------------
dnl  Determine a math library -lquadmath to use.

AC_DEFUN([MPFR_CHECK_LIBQUADMATH],
[AC_REQUIRE([AC_CANONICAL_HOST])
AC_SUBST(MPFR_LIBQUADMATH,'')
case $host in
  *)
    AC_CHECK_LIB(quadmath, main, MPFR_LIBQUADMATH="-lquadmath")
    ;;
esac
])

dnl  MPFR_LD_SEARCH_PATHS_FIRST
dnl  --------------------------

AC_DEFUN([MPFR_LD_SEARCH_PATHS_FIRST],
[case "$LD $LDFLAGS" in
  *-Wl,-search_paths_first*) ;;
  *) AC_MSG_CHECKING([if the compiler understands -Wl,-search_paths_first])
     saved_LDFLAGS="$LDFLAGS"
     LDFLAGS="-Wl,-search_paths_first $LDFLAGS"
     AC_LINK_IFELSE([AC_LANG_PROGRAM([[]], [[]])],
       [AC_MSG_RESULT(yes)],
       [AC_MSG_RESULT(no)]
        LDFLAGS="$saved_LDFLAGS")
     ;;
 esac
])


dnl  GMP_C_ATTRIBUTE_MODE
dnl  --------------------
dnl  Introduced in gcc 2.2, but perhaps not in all Apple derived versions.
dnl  Needed for mpfr-longlong.h; this is currently necessary for s390.
dnl
dnl  TODO: Replace this with a cleaner type size detection, as this
dnl  solution only works with gcc and assumes CHAR_BIT == 8. Probably use
dnl  <stdint.h>, and <https://gcc.gnu.org/viewcvs/gcc/trunk/config/stdint.m4>
dnl  as a fallback.

AC_DEFUN([GMP_C_ATTRIBUTE_MODE],
[AC_CACHE_CHECK([whether gcc __attribute__ ((mode (XX))) works],
               gmp_cv_c_attribute_mode,
[AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[typedef int SItype __attribute__ ((mode (SI)));]], [[]])],
 gmp_cv_c_attribute_mode=yes, gmp_cv_c_attribute_mode=no)
])
if test $gmp_cv_c_attribute_mode = yes; then
 AC_DEFINE(HAVE_ATTRIBUTE_MODE, 1,
 [Define to 1 if the compiler accepts gcc style __attribute__ ((mode (XX)))])
fi
])


dnl  MPFR_FUNC_GMP_PRINTF_SPEC
dnl  ------------------------------------
dnl  MPFR_FUNC_GMP_PRINTF_SPEC(spec, type, [includes], [if-true], [if-false])
dnl  Check if gmp_sprintf supports the conversion specification 'spec'
dnl  with type 'type'.
dnl  Expand 'if-true' if printf supports 'spec', 'if-false' otherwise.

AC_DEFUN([MPFR_FUNC_GMP_PRINTF_SPEC],[
AC_MSG_CHECKING(if gmp_printf supports "%$1")
AC_RUN_IFELSE([AC_LANG_PROGRAM([[
#include <stdio.h>
#include <string.h>
$3
#include <gmp.h>
]], [[
  char s[256];
  $2 a = 17;

  if (gmp_sprintf (s, "(%0.0$1)(%d)", a, 42) == -1) return 1;
  return (strcmp (s, "(17)(42)") != 0);
]])],
  [AC_MSG_RESULT(yes)
  $4],
  [AC_MSG_RESULT(no)
  $5],
  [AC_MSG_RESULT(cross-compiling, assuming yes)
  $4])
])


dnl MPFR_CHECK_PRINTF_SPEC
dnl ----------------------
dnl Check if gmp_printf supports some optional length modifiers.
dnl Defined symbols are negative to shorten the gcc command line.

AC_DEFUN([MPFR_CHECK_PRINTF_SPEC], [
AC_REQUIRE([MPFR_CONFIGS])dnl
if test "$ac_cv_type_intmax_t" = yes; then
 MPFR_FUNC_GMP_PRINTF_SPEC([jd], [intmax_t], [
#ifdef HAVE_INTTYPES_H
# include <inttypes.h>
#endif
#ifdef HAVE_STDINT_H
# include <stdint.h>
#endif
         ],,
         [AC_DEFINE([NPRINTF_J], 1, [gmp_printf cannot read intmax_t])])
fi

MPFR_FUNC_GMP_PRINTF_SPEC([hhd], [char], [
#include <gmp.h>
         ],,
         [AC_DEFINE([NPRINTF_HH], 1, [gmp_printf cannot use `hh' length modifier])])

MPFR_FUNC_GMP_PRINTF_SPEC([lld], [long long int], [
#include <gmp.h>
         ],,
         [AC_DEFINE([NPRINTF_LL], 1, [gmp_printf cannot read long long int])])

MPFR_FUNC_GMP_PRINTF_SPEC([Lf], [long double], [
#include <gmp.h>
         ],
         [AC_DEFINE([PRINTF_L], 1, [gmp_printf can read long double])],
         [AC_DEFINE([NPRINTF_L], 1, [gmp_printf cannot read long double])])

MPFR_FUNC_GMP_PRINTF_SPEC([td], [ptrdiff_t], [
#if defined (__cplusplus)
#include <cstddef>
#else
#include <stddef.h>
#endif
#include <gmp.h>
    ],
    [AC_DEFINE([PRINTF_T], 1, [gmp_printf can read ptrdiff_t])],
    [AC_DEFINE([NPRINTF_T], 1, [gmp_printf cannot read ptrdiff_t])])
])