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Diffstat (limited to 'm4/isinf.m4')
-rw-r--r-- | m4/isinf.m4 | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/m4/isinf.m4 b/m4/isinf.m4 new file mode 100644 index 000000000..6a2412350 --- /dev/null +++ b/m4/isinf.m4 @@ -0,0 +1,48 @@ +# isinf.m4 serial 3 +dnl Copyright (C) 2007-2010 Free Software Foundation, Inc. +dnl This file is free software; the Free Software Foundation +dnl gives unlimited permission to copy and/or distribute it, +dnl with or without modifications, as long as this notice is preserved. + +AC_DEFUN([gl_ISINF], +[ + AC_REQUIRE([gl_MATH_H_DEFAULTS]) + dnl Persuade glibc <math.h> to declare isinf. + AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS]) + AC_CHECK_DECLS([isinf], , , [#include <math.h>]) + if test "$ac_cv_have_decl_isinf" = yes; then + gl_CHECK_MATH_LIB([ISINF_LIBM], [x = isinf (x);]) + if test "$ISINF_LIBM" != missing; then + dnl Test whether isinf() on 'long double' works. + gl_ISINFL_WORKS + case "$gl_cv_func_isinfl_works" in + *yes) ;; + *) ISINF_LIBM=missing;; + esac + fi + fi + if test "$ac_cv_have_decl_isinf" != yes || + test "$ISINF_LIBM" = missing; then + REPLACE_ISINF=1 + AC_LIBOBJ([isinf]) + ISINF_LIBM= + fi + AC_SUBST([ISINF_LIBM]) +]) + +dnl Test whether isinf() correctly returns false for LDBL_MAX. +AC_DEFUN([gl_ISINFL_WORKS], +[ + AC_REQUIRE([AC_PROG_CC]) + AC_REQUIRE([gl_BIGENDIAN]) + AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles + AC_CACHE_CHECK([whether isinf(long double) works], [gl_cv_func_isinfl_works], + [ + AC_RUN_IFELSE([AC_LANG_PROGRAM([[#include <float.h> + #include <math.h>]], + [[return !!isinf(LDBL_MAX);]])], + [gl_cv_func_isinfl_works=yes], + [gl_cv_func_isinfl_works=no], + [gl_cv_func_isinfl_works="guessing no"]) + ]) +]) |