2 dnl Copyright (C) 2007-2010 Free Software Foundation, Inc.
3 dnl This file is free software; the Free Software Foundation
4 dnl gives unlimited permission to copy and/or distribute it,
5 dnl with or without modifications, as long as this notice is preserved.
7 AC_DEFUN([gl_FUNC_ISNANL],
9 AC_REQUIRE([gl_MATH_H_DEFAULTS])
11 gl_HAVE_ISNANL_NO_LIBM
12 if test $gl_cv_func_isnanl_no_libm = no; then
13 gl_HAVE_ISNANL_IN_LIBM
14 if test $gl_cv_func_isnanl_in_libm = yes; then
18 if test $gl_cv_func_isnanl_no_libm = yes \
19 || test $gl_cv_func_isnanl_in_libm = yes; then
21 LIBS="$LIBS $ISNANL_LIBM"
24 case "$gl_cv_func_isnanl_works" in
25 *yes) gl_func_isnanl=yes ;;
26 *) gl_func_isnanl=no; ISNANL_LIBM= ;;
31 if test $gl_func_isnanl != yes; then
35 AC_SUBST([ISNANL_LIBM])
38 AC_DEFUN([gl_FUNC_ISNANL_NO_LIBM],
40 gl_HAVE_ISNANL_NO_LIBM
41 gl_func_isnanl_no_libm=$gl_cv_func_isnanl_no_libm
42 if test $gl_func_isnanl_no_libm = yes; then
44 case "$gl_cv_func_isnanl_works" in
46 *) gl_func_isnanl_no_libm=no ;;
49 if test $gl_func_isnanl_no_libm = yes; then
50 AC_DEFINE([HAVE_ISNANL_IN_LIBC], [1],
51 [Define if the isnan(long double) function is available in libc.])
57 dnl Pull in replacement isnanl definition. It does not need -lm.
58 AC_DEFUN([gl_BUILD_ISNANL],
61 gl_LONG_DOUBLE_EXPONENT_LOCATION
64 dnl Test whether isnanl() can be used without libm.
65 AC_DEFUN([gl_HAVE_ISNANL_NO_LIBM],
67 AC_CACHE_CHECK([whether isnan(long double) can be used without linking with libm],
68 [gl_cv_func_isnanl_no_libm],
75 # define isnanl(x) __builtin_isnanl ((long double)(x))
78 # define isnanl(x) isnan ((long double)(x))
81 [[return isnanl (x);]])],
82 [gl_cv_func_isnanl_no_libm=yes],
83 [gl_cv_func_isnanl_no_libm=no])
87 dnl Test whether isnanl() can be used with libm.
88 AC_DEFUN([gl_HAVE_ISNANL_IN_LIBM],
90 AC_CACHE_CHECK([whether isnan(long double) can be used with libm],
91 [gl_cv_func_isnanl_in_libm],
100 # define isnanl(x) __builtin_isnanl ((long double)(x))
103 # define isnanl(x) isnan ((long double)(x))
106 [[return isnanl (x);]])],
107 [gl_cv_func_isnanl_in_libm=yes],
108 [gl_cv_func_isnanl_in_libm=no])
113 dnl Test whether isnanl() recognizes all numbers which are neither finite nor
114 dnl infinite. This test fails e.g. on NetBSD/i386 and on glibc/ia64.
115 dnl Also, the GCC >= 4.0 built-in __builtin_isnanl does not pass the tests
116 dnl - for pseudo-denormals on i686 and x86_64,
117 dnl - for pseudo-zeroes, unnormalized numbers, and pseudo-denormals on ia64.
118 AC_DEFUN([gl_FUNC_ISNANL_WORKS],
120 AC_REQUIRE([AC_PROG_CC])
121 AC_REQUIRE([gl_BIGENDIAN])
122 AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
123 AC_CACHE_CHECK([whether isnanl works], [gl_cv_func_isnanl_works],
132 # define isnanl(x) __builtin_isnanl ((long double)(x))
135 # define isnanl(x) isnan ((long double)(x))
138 ((sizeof (long double) + sizeof (unsigned int) - 1) / sizeof (unsigned int))
139 typedef union { unsigned int word[NWORDS]; long double value; }
141 /* On Irix 6.5, gcc 3.4.3 can't compute compile-time NaN, and needs the
142 runtime type conversion. */
144 static long double NaNl ()
150 # define NaNl() (0.0L / 0.0L)
154 memory_long_double m;
157 if (!isnanl (NaNl ()))
160 /* The isnanl function should be immune against changes in the sign bit and
161 in the mantissa bits. The xor operation twiddles a bit that can only be
162 a sign bit or a mantissa bit (since the exponent never extends to
165 m.word[NWORDS / 2] ^= (unsigned int) 1 << (sizeof (unsigned int) * CHAR_BIT - 1);
166 for (i = 0; i < NWORDS; i++)
168 if (!isnanl (m.value))
171 #if ((defined __ia64 && LDBL_MANT_DIG == 64) || (defined __x86_64__ || defined __amd64__) || (defined __i386 || defined __i386__ || defined _I386 || defined _M_IX86 || defined _X86_))
172 /* Representation of an 80-bit 'long double' as an initializer for a sequence
173 of 'unsigned int' words. */
174 # ifdef WORDS_BIGENDIAN
175 # define LDBL80_WORDS(exponent,manthi,mantlo) \
176 { ((unsigned int) (exponent) << 16) | ((unsigned int) (manthi) >> 16), \
177 ((unsigned int) (manthi) << 16) | (unsigned int) (mantlo) >> 16), \
178 (unsigned int) (mantlo) << 16 \
181 # define LDBL80_WORDS(exponent,manthi,mantlo) \
182 { mantlo, manthi, exponent }
185 static memory_long_double x =
186 { LDBL80_WORDS (0xFFFF, 0xC3333333, 0x00000000) };
187 if (!isnanl (x.value))
191 /* Signalling NaN. */
192 static memory_long_double x =
193 { LDBL80_WORDS (0xFFFF, 0x83333333, 0x00000000) };
194 if (!isnanl (x.value))
197 /* The isnanl function should recognize Pseudo-NaNs, Pseudo-Infinities,
198 Pseudo-Zeroes, Unnormalized Numbers, and Pseudo-Denormals, as defined in
199 Intel IA-64 Architecture Software Developer's Manual, Volume 1:
200 Application Architecture.
201 Table 5-2 "Floating-Point Register Encodings"
202 Figure 5-6 "Memory to Floating-Point Register Data Translation"
205 static memory_long_double x =
206 { LDBL80_WORDS (0xFFFF, 0x40000001, 0x00000000) };
207 if (!isnanl (x.value))
210 { /* Pseudo-Infinity. */
211 static memory_long_double x =
212 { LDBL80_WORDS (0xFFFF, 0x00000000, 0x00000000) };
213 if (!isnanl (x.value))
217 static memory_long_double x =
218 { LDBL80_WORDS (0x4004, 0x00000000, 0x00000000) };
219 if (!isnanl (x.value))
222 { /* Unnormalized number. */
223 static memory_long_double x =
224 { LDBL80_WORDS (0x4000, 0x63333333, 0x00000000) };
225 if (!isnanl (x.value))
228 { /* Pseudo-Denormal. */
229 static memory_long_double x =
230 { LDBL80_WORDS (0x0000, 0x83333333, 0x00000000) };
231 if (!isnanl (x.value))
238 [gl_cv_func_isnanl_works=yes],
239 [gl_cv_func_isnanl_works=no],
241 # Guess no on ia64, x86_64, i386.
242 ia64 | x86_64 | i*86) gl_cv_func_isnanl_works="guessing no";;
245 netbsd*) gl_cv_func_isnanl_works="guessing no";;
246 *) gl_cv_func_isnanl_works="guessing yes";;