| # floor.m4 serial 14 |
| dnl Copyright (C) 2007, 2009-2020 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_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" |
| ]) |