# exp2l.m4 serial 11 dnl Copyright (C) 2010-2023 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_EXP2L], [ m4_divert_text([DEFAULTS], [gl_exp2l_required=plain]) AC_REQUIRE([gl_MATH_H_DEFAULTS]) AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE]) AC_REQUIRE([gl_FUNC_EXP2]) dnl Persuade glibc to declare exp2l(). AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS]) dnl Test whether exp2l() exists. Assume that exp2l(), if it exists, is dnl defined in the same library as exp2(). save_LIBS="$LIBS" LIBS="$LIBS $EXP2_LIBM" AC_CHECK_FUNCS([exp2l]) LIBS="$save_LIBS" if test $ac_cv_func_exp2l = yes; then HAVE_EXP2L=1 EXP2L_LIBM="$EXP2_LIBM" dnl Also check whether it's declared. dnl IRIX 6.5 has exp2l() in libm but doesn't declare it in . AC_CHECK_DECL([exp2l], , [HAVE_DECL_EXP2L=0], [[#include ]]) if test $REPLACE_EXP2L = 0; then AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles AC_CACHE_CHECK([whether exp2l works], [gl_cv_func_exp2l_works], [ save_LIBS="$LIBS" LIBS="$LIBS $EXP2L_LIBM" AC_RUN_IFELSE( [AC_LANG_SOURCE([[ #ifndef __NO_MATH_INLINES # define __NO_MATH_INLINES 1 /* for glibc */ #endif #include #include /* Override the values of , like done in float.in.h. */ #if defined __i386__ && (defined __BEOS__ || defined __OpenBSD__) # undef LDBL_MANT_DIG # define LDBL_MANT_DIG 64 # undef LDBL_MIN_EXP # define LDBL_MIN_EXP (-16381) # undef LDBL_MAX_EXP # define LDBL_MAX_EXP 16384 #endif #if defined __i386__ && (defined __FreeBSD__ || defined __DragonFly__) # undef LDBL_MANT_DIG # define LDBL_MANT_DIG 64 # undef LDBL_MIN_EXP # define LDBL_MIN_EXP (-16381) # undef LDBL_MAX_EXP # define LDBL_MAX_EXP 16384 #endif #if (defined _ARCH_PPC || defined _POWER) && defined _AIX && (LDBL_MANT_DIG == 106) && defined __GNUC__ # undef LDBL_MIN_EXP # define LDBL_MIN_EXP DBL_MIN_EXP #endif #if defined __sgi && (LDBL_MANT_DIG >= 106) # undef LDBL_MANT_DIG # define LDBL_MANT_DIG 106 # if defined __GNUC__ # undef LDBL_MIN_EXP # define LDBL_MIN_EXP DBL_MIN_EXP # endif #endif #undef exp2l extern #ifdef __cplusplus "C" #endif long double exp2l (long double); static long double dummy (long double x) { return 0; } int main (int argc, char *argv[]) { long double (* volatile my_exp2l) (long double) = argc ? exp2l : dummy; int result = 0; /* This test fails on NetBSD 9.0. */ { const long double TWO_LDBL_MANT_DIG = /* 2^LDBL_MANT_DIG */ (long double) (1U << ((LDBL_MANT_DIG - 1) / 5)) * (long double) (1U << ((LDBL_MANT_DIG - 1 + 1) / 5)) * (long double) (1U << ((LDBL_MANT_DIG - 1 + 2) / 5)) * (long double) (1U << ((LDBL_MANT_DIG - 1 + 3) / 5)) * (long double) (1U << ((LDBL_MANT_DIG - 1 + 4) / 5)); long double x = 11.358L; long double err = (my_exp2l (x) * my_exp2l (- x) - 1.0L) * TWO_LDBL_MANT_DIG; if (!(err >= -100.0L && err <= 100.0L)) result |= 1; } return result; } ]])], [gl_cv_func_exp2l_works=yes], [gl_cv_func_exp2l_works=no], [case "$host_os" in # Guess yes on glibc systems. *-gnu* | gnu*) gl_cv_func_exp2l_works="guessing yes" ;; # Guess yes on musl systems. *-musl* | midipix*) gl_cv_func_exp2l_works="guessing yes" ;; # Guess yes on native Windows. mingw*) gl_cv_func_exp2l_works="guessing yes" ;; # If we don't know, obey --enable-cross-guesses. *) gl_cv_func_exp2l_works="$gl_cross_guess_normal" ;; esac ]) LIBS="$save_LIBS" ]) case "$gl_cv_func_exp2l_works" in *yes) ;; *) REPLACE_EXP2L=1 ;; esac fi m4_ifdef([gl_FUNC_EXP2L_IEEE], [ if test $gl_exp2l_required = ieee && test $REPLACE_EXP2L = 0; then AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles AC_CACHE_CHECK([whether exp2l works according to ISO C 99 with IEC 60559], [gl_cv_func_exp2l_ieee], [ save_LIBS="$LIBS" LIBS="$LIBS $EXP2L_LIBM" AC_RUN_IFELSE( [AC_LANG_SOURCE([[ #ifndef __NO_MATH_INLINES # define __NO_MATH_INLINES 1 /* for glibc */ #endif #include #undef exp2l extern #ifdef __cplusplus "C" #endif long double exp2l (long double); static long double dummy (long double x) { return 0; } static long double zero; int main (int argc, char *argv[]) { long double (* volatile my_exp2l) (long double) = argc ? exp2l : dummy; int result = 0; /* This test fails on OpenBSD 4.9, where exp2l(NaN) = 0.0. */ if (exp2l (zero / zero) == 0.0L) result |= 1; /* This test fails on IRIX 6.5, where exp2l(-Inf) = 1.0. */ if (!(exp2l (-1.0L / zero) == 0.0L)) result |= 2; return result; } ]])], [gl_cv_func_exp2l_ieee=yes], [gl_cv_func_exp2l_ieee=no], [case "$host_os" in # Guess yes on glibc systems. *-gnu* | gnu*) gl_cv_func_exp2l_ieee="guessing yes" ;; # Guess yes on musl systems. *-musl* | midipix*) gl_cv_func_exp2l_ieee="guessing yes" ;; # Guess yes on native Windows. mingw*) gl_cv_func_exp2l_ieee="guessing yes" ;; # If we don't know, obey --enable-cross-guesses. *) gl_cv_func_exp2l_ieee="$gl_cross_guess_normal" ;; esac ]) LIBS="$save_LIBS" ]) case "$gl_cv_func_exp2l_ieee" in *yes) ;; *) REPLACE_EXP2L=1 ;; esac fi ]) else HAVE_EXP2L=0 HAVE_DECL_EXP2L=0 fi if test $HAVE_EXP2L = 0 || test $REPLACE_EXP2L = 1; then dnl Find libraries needed to link lib/exp2l.c. if test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1; then EXP2L_LIBM="$EXP2_LIBM" else AC_REQUIRE([gl_FUNC_ISNANL]) AC_REQUIRE([gl_FUNC_ROUNDL]) AC_REQUIRE([gl_FUNC_LDEXPL]) EXP2L_LIBM= dnl Append $ISNANL_LIBM to EXP2L_LIBM, avoiding gratuitous duplicates. case " $EXP2L_LIBM " in *" $ISNANL_LIBM "*) ;; *) EXP2L_LIBM="$EXP2L_LIBM $ISNANL_LIBM" ;; esac dnl Append $ROUNDL_LIBM to EXP2L_LIBM, avoiding gratuitous duplicates. case " $EXP2L_LIBM " in *" $ROUNDL_LIBM "*) ;; *) EXP2L_LIBM="$EXP2L_LIBM $ROUNDL_LIBM" ;; esac dnl Append $LDEXPL_LIBM to EXP2L_LIBM, avoiding gratuitous duplicates. case " $EXP2L_LIBM " in *" $LDEXPL_LIBM "*) ;; *) EXP2L_LIBM="$EXP2L_LIBM $LDEXPL_LIBM" ;; esac fi fi AC_SUBST([EXP2L_LIBM]) ])