| # modfl.m4 serial 8 |
| dnl Copyright (C) 2011-2020 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_FUNC_MODFL], |
| [ |
| m4_divert_text([DEFAULTS], [gl_modfl_required=plain]) |
| AC_REQUIRE([gl_MATH_H_DEFAULTS]) |
| AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE]) |
| |
| dnl Persuade glibc <math.h> to declare modfl(). |
| AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS]) |
| |
| dnl Test whether modfl() exists. We cannot assume that modfl(), if it |
| dnl exists, is defined in the same library as modf(). This is not the case |
| dnl on FreeBSD, Solaris. |
| gl_MATHFUNC([modfl], [long double], [(long double, long double *)]) |
| if test $gl_cv_func_modfl_no_libm = yes \ |
| || test $gl_cv_func_modfl_in_libm = yes; then |
| : |
| m4_ifdef([gl_FUNC_MODFL_IEEE], [ |
| if test $gl_modfl_required = ieee && test $REPLACE_MODFL = 0; then |
| AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles |
| AC_CACHE_CHECK([whether modfl works according to ISO C 99 with IEC 60559], |
| [gl_cv_func_modfl_ieee], |
| [ |
| save_LIBS="$LIBS" |
| LIBS="$LIBS $MODFL_LIBM" |
| AC_RUN_IFELSE( |
| [AC_LANG_SOURCE([[ |
| #ifndef __NO_MATH_INLINES |
| # define __NO_MATH_INLINES 1 /* for glibc */ |
| #endif |
| #include <math.h> |
| ]gl_LONG_DOUBLE_MINUS_ZERO_CODE[ |
| ]gl_LONG_DOUBLE_SIGNBIT_CODE[ |
| /* Compare two numbers with ==. |
| This is a separate function because IRIX 6.5 "cc -O" miscompiles an |
| 'x == x' test. */ |
| static int |
| numeric_equal (long double x, long double y) |
| { |
| return x == y; |
| } |
| static long double dummy (long double x, long double *iptr) { return 0; } |
| long double zero; |
| long double minus_one = - 1.0L; |
| int main (int argc, char *argv[]) |
| { |
| long double (* volatile my_modfl) (long double, long double *) = argc ? modfl : dummy; |
| long double i; |
| long double f; |
| /* Test modfl(-Inf,...). |
| This test fails on IRIX 6.5, OSF/1 5.1, mingw. */ |
| f = my_modfl (minus_one / zero, &i); |
| if (!(f == 0.0L) || (signbitl (minus_zerol) && !signbitl (f))) |
| return 1; |
| return 0; |
| } |
| ]])], |
| [gl_cv_func_modfl_ieee=yes], |
| [gl_cv_func_modfl_ieee=no], |
| [case "$host_os" in |
| # Guess yes on glibc systems. |
| *-gnu* | gnu*) gl_cv_func_modfl_ieee="guessing yes" ;; |
| # Guess yes on musl systems. |
| *-musl*) gl_cv_func_modfl_ieee="guessing yes" ;; |
| # Guess yes on MSVC, no on mingw. |
| mingw*) AC_EGREP_CPP([Known], [ |
| #ifdef _MSC_VER |
| Known |
| #endif |
| ], |
| [gl_cv_func_modfl_ieee="guessing yes"], |
| [gl_cv_func_modfl_ieee="guessing no"]) |
| ;; |
| # If we don't know, obey --enable-cross-guesses. |
| *) gl_cv_func_modfl_ieee="$gl_cross_guess_normal" ;; |
| esac |
| ]) |
| LIBS="$save_LIBS" |
| ]) |
| case "$gl_cv_func_modfl_ieee" in |
| *yes) ;; |
| *) REPLACE_MODFL=1 ;; |
| esac |
| fi |
| ]) |
| else |
| HAVE_MODFL=0 |
| fi |
| if test $HAVE_MODFL = 0 || test $REPLACE_MODFL = 1; then |
| dnl Find libraries needed to link lib/modfl.c. |
| if test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1; then |
| AC_REQUIRE([gl_FUNC_MODF]) |
| MODFL_LIBM="$MODF_LIBM" |
| else |
| AC_REQUIRE([gl_FUNC_TRUNCL]) |
| MODFL_LIBM="$TRUNCL_LIBM" |
| fi |
| fi |
| AC_SUBST([MODFL_LIBM]) |
| ]) |