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Diffstat (limited to 'm4/floor.m4')
-rw-r--r-- | m4/floor.m4 | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/m4/floor.m4 b/m4/floor.m4 new file mode 100644 index 000000000..63e56d395 --- /dev/null +++ b/m4/floor.m4 @@ -0,0 +1,103 @@ +# floor.m4 serial 14 +dnl Copyright (C) 2007, 2009-2023 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_FLOOR], +[ + m4_divert_text([DEFAULTS], [gl_floor_required=plain]) + AC_REQUIRE([gl_MATH_H_DEFAULTS]) + dnl Test whether floor() can be used without libm. + gl_FUNC_FLOOR_LIBS + if test "$FLOOR_LIBM" = "?"; then + FLOOR_LIBM= + fi + m4_ifdef([gl_FUNC_FLOOR_IEEE], [ + if test $gl_floor_required = ieee && test $REPLACE_FLOOR = 0; then + AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles + AC_CACHE_CHECK([whether floor works according to ISO C 99 with IEC 60559], + [gl_cv_func_floor_ieee], + [ + save_LIBS="$LIBS" + LIBS="$LIBS $FLOOR_LIBM" + AC_RUN_IFELSE( + [AC_LANG_SOURCE([[ +#ifndef __NO_MATH_INLINES +# define __NO_MATH_INLINES 1 /* for glibc */ +#endif +#include <math.h> +]gl_DOUBLE_MINUS_ZERO_CODE[ +]gl_DOUBLE_SIGNBIT_CODE[ +static double dummy (double f) { return 0; } +int main (int argc, char *argv[]) +{ + double (* volatile my_floor) (double) = argc ? floor : dummy; + /* Test whether floor (-0.0) is -0.0. */ + if (signbitd (minus_zerod) && !signbitd (my_floor (minus_zerod))) + return 1; + return 0; +} + ]])], + [gl_cv_func_floor_ieee=yes], + [gl_cv_func_floor_ieee=no], + [case "$host_os" in + # Guess yes on glibc systems. + *-gnu* | gnu*) gl_cv_func_floor_ieee="guessing yes" ;; + # Guess yes on musl systems. + *-musl*) gl_cv_func_floor_ieee="guessing yes" ;; + # Guess yes on native Windows. + mingw*) gl_cv_func_floor_ieee="guessing yes" ;; + # If we don't know, obey --enable-cross-guesses. + *) gl_cv_func_floor_ieee="$gl_cross_guess_normal" ;; + esac + ]) + LIBS="$save_LIBS" + ]) + case "$gl_cv_func_floor_ieee" in + *yes) ;; + *) REPLACE_FLOOR=1 ;; + esac + fi + ]) + if test $REPLACE_FLOOR = 1; then + dnl No libraries are needed to link lib/floor.c. + FLOOR_LIBM= + fi + AC_SUBST([FLOOR_LIBM]) +]) + +# Determines the libraries needed to get the floor() function. +# Sets FLOOR_LIBM. +AC_DEFUN([gl_FUNC_FLOOR_LIBS], +[ + gl_CACHE_VAL_SILENT([gl_cv_func_floor_libm], [ + gl_cv_func_floor_libm=? + AC_LINK_IFELSE( + [AC_LANG_PROGRAM( + [[#ifndef __NO_MATH_INLINES + # define __NO_MATH_INLINES 1 /* for glibc */ + #endif + #include <math.h> + double (*funcptr) (double) = floor; + double x;]], + [[x = funcptr(x) + floor(x);]])], + [gl_cv_func_floor_libm=]) + if test "$gl_cv_func_floor_libm" = "?"; then + save_LIBS="$LIBS" + LIBS="$LIBS -lm" + AC_LINK_IFELSE( + [AC_LANG_PROGRAM( + [[#ifndef __NO_MATH_INLINES + # define __NO_MATH_INLINES 1 /* for glibc */ + #endif + #include <math.h> + double (*funcptr) (double) = floor; + double x;]], + [[x = funcptr(x) + floor(x);]])], + [gl_cv_func_floor_libm="-lm"]) + LIBS="$save_LIBS" + fi + ]) + FLOOR_LIBM="$gl_cv_func_floor_libm" +]) |