1 # isnand.m4 serial 11 2 dnl Copyright (C) 2007-2012 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. 6 7 dnl Check how to get or define isnand(). 8 9 AC_DEFUN([gl_FUNC_ISNAND], 10 [ 11 AC_REQUIRE([gl_MATH_H_DEFAULTS]) 12 ISNAND_LIBM= 13 gl_HAVE_ISNAND_NO_LIBM 14 if test $gl_cv_func_isnand_no_libm = no; then 15 gl_HAVE_ISNAND_IN_LIBM 16 if test $gl_cv_func_isnand_in_libm = yes; then 17 ISNAND_LIBM=-lm 18 fi 19 fi 20 dnl The variable gl_func_isnand set here is used by isnan.m4. 21 if test $gl_cv_func_isnand_no_libm = yes \ 22 || test $gl_cv_func_isnand_in_libm = yes; then 23 gl_func_isnand=yes 24 else 25 gl_func_isnand=no 26 HAVE_ISNAND=0 27 fi 28 AC_SUBST([ISNAND_LIBM]) 29 ]) 30 31 dnl Check how to get or define isnand() without linking with libm. 32 33 AC_DEFUN([gl_FUNC_ISNAND_NO_LIBM], 34 [ 35 gl_HAVE_ISNAND_NO_LIBM 36 gl_func_isnand_no_libm=$gl_cv_func_isnand_no_libm 37 if test $gl_cv_func_isnand_no_libm = yes; then 38 AC_DEFINE([HAVE_ISNAND_IN_LIBC], [1], 39 [Define if the isnan(double) function is available in libc.]) 40 fi 41 ]) 42 43 dnl Prerequisites of replacement isnand definition. It does not need -lm. 44 AC_DEFUN([gl_PREREQ_ISNAND], 45 [ 46 AC_REQUIRE([gl_DOUBLE_EXPONENT_LOCATION]) 47 ]) 48 49 dnl Test whether isnand() can be used with libm. 50 51 AC_DEFUN([gl_HAVE_ISNAND_IN_LIBM], 52 [ 53 AC_CACHE_CHECK([whether isnan(double) can be used with libm], 54 [gl_cv_func_isnand_in_libm], 55 [ 56 save_LIBS="$LIBS" 57 LIBS="$LIBS -lm" 58 AC_LINK_IFELSE( 59 [AC_LANG_PROGRAM( 60 [[#include <math.h> 61 #if __GNUC__ >= 4 62 # undef isnand 63 # define isnand(x) __builtin_isnan ((double)(x)) 64 #elif defined isnan 65 # undef isnand 66 # define isnand(x) isnan ((double)(x)) 67 #endif 68 double x;]], 69 [[return isnand (x);]])], 70 [gl_cv_func_isnand_in_libm=yes], 71 [gl_cv_func_isnand_in_libm=no]) 72 LIBS="$save_LIBS" 73 ]) 74 ]) 75 76 AC_DEFUN([gl_HAVE_ISNAND_NO_LIBM], 77 [ 78 AC_CACHE_CHECK([whether isnan(double) can be used without linking with libm], 79 [gl_cv_func_isnand_no_libm], 80 [ 81 AC_LINK_IFELSE( 82 [AC_LANG_PROGRAM( 83 [[#include <math.h> 84 #if __GNUC__ >= 4 85 # undef isnand 86 # define isnand(x) __builtin_isnan ((double)(x)) 87 #else 88 # undef isnand 89 # define isnand(x) isnan ((double)(x)) 90 #endif 91 double x;]], 92 [[return isnand (x);]])], 93 [gl_cv_func_isnand_no_libm=yes], 94 [gl_cv_func_isnand_no_libm=no]) 95 ]) 96 ]) 97
