# expm1l.m4 serial 11 dnl Copyright (C) 2010-2024 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_EXPM1L], [ AC_REQUIRE([gl_MATH_H_DEFAULTS]) AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE]) dnl Persuade glibc to declare expm1l(). AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS]) EXPM1L_LIBM= AC_CACHE_CHECK([whether expm1l() can be used without linking with libm], [gl_cv_func_expm1l_no_libm], [ AC_LINK_IFELSE( [AC_LANG_PROGRAM( [[#ifndef __NO_MATH_INLINES # define __NO_MATH_INLINES 1 /* for glibc */ #endif #include extern #ifdef __cplusplus "C" #endif long double expm1l (long double); long double (* volatile funcptr) (long double) = expm1l; long double x;]], [[return funcptr (x) > 0.5 || expm1l (x) > 0.5;]])], [gl_cv_func_expm1l_no_libm=yes], [gl_cv_func_expm1l_no_libm=no]) ]) if test $gl_cv_func_expm1l_no_libm = no; then AC_CACHE_CHECK([whether expm1l() can be used with libm], [gl_cv_func_expm1l_in_libm], [ save_LIBS="$LIBS" LIBS="$LIBS -lm" AC_LINK_IFELSE( [AC_LANG_PROGRAM( [[#ifndef __NO_MATH_INLINES # define __NO_MATH_INLINES 1 /* for glibc */ #endif #include extern #ifdef __cplusplus "C" #endif long double expm1l (long double); long double (* volatile funcptr) (long double) = expm1l; long double x;]], [[return funcptr (x) > 0.5 || expm1l (x) > 0.5;]])], [gl_cv_func_expm1l_in_libm=yes], [gl_cv_func_expm1l_in_libm=no]) LIBS="$save_LIBS" ]) if test $gl_cv_func_expm1l_in_libm = yes; then EXPM1L_LIBM=-lm fi fi if test $gl_cv_func_expm1l_no_libm = yes \ || test $gl_cv_func_expm1l_in_libm = yes; then HAVE_EXPM1L=1 dnl Also check whether it's declared. dnl IRIX 6.5 has expm1l() in libm but doesn't declare it in . AC_CHECK_DECL([expm1l], , [HAVE_DECL_EXPM1L=0], [[#include ]]) if test $REPLACE_EXPM1L = 0; then AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles AC_CACHE_CHECK([whether expm1l works], [gl_cv_func_expm1l_works], [ save_LIBS="$LIBS" LIBS="$LIBS $EXPM1L_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 expm1l extern #ifdef __cplusplus "C" #endif long double expm1l (long double); static long double dummy (long double x) { return 0; } int main (int argc, char *argv[]) { long double (* volatile my_expm1l) (long double) = argc ? expm1l : dummy; int result = 0; /* This test fails on musl 1.2.2/arm64, musl 1.2.2/s390x, Mac OS X 10.5, NetBSD 8.0. */ { 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 y = my_expm1l (x); long double z = my_expm1l (- x); volatile long double t = (1.0L + y) * z; long double err = (y + t) * TWO_LDBL_MANT_DIG; if (!(err >= -100.0L && err <= 100.0L)) result |= 1; } return result; } ]])], [gl_cv_func_expm1l_works=yes], [gl_cv_func_expm1l_works=no], [case "$host_os" in # Guess yes on glibc systems. *-gnu* | gnu*) gl_cv_func_expm1l_works="guessing yes" ;; # Guess no on musl systems. *-musl* | midipix*) gl_cv_func_expm1l_works="guessing no" ;; # Guess yes on native Windows. mingw* | windows*) gl_cv_func_expm1l_works="guessing yes" ;; # If we don't know, obey --enable-cross-guesses. *) gl_cv_func_expm1l_works="$gl_cross_guess_normal" ;; esac ]) LIBS="$save_LIBS" ]) case "$gl_cv_func_expm1l_works" in *yes) ;; *) REPLACE_EXPM1L=1 ;; esac fi else HAVE_EXPM1L=0 HAVE_DECL_EXPM1L=0 fi if test $HAVE_EXPM1L = 0 || test $REPLACE_EXPM1L = 1; then dnl Find libraries needed to link lib/expm1l.c. if test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1; then AC_REQUIRE([gl_FUNC_EXPM1]) EXPM1L_LIBM="$EXPM1_LIBM" else AC_REQUIRE([gl_FUNC_ISNANL]) AC_REQUIRE([gl_FUNC_EXPL]) AC_REQUIRE([gl_FUNC_ROUNDL]) AC_REQUIRE([gl_FUNC_LDEXPL]) EXPM1L_LIBM= dnl Append $ISNANL_LIBM to EXPM1L_LIBM, avoiding gratuitous duplicates. case " $EXPM1L_LIBM " in *" $ISNANL_LIBM "*) ;; *) EXPM1L_LIBM="$EXPM1L_LIBM $ISNANL_LIBM" ;; esac dnl Append $EXPL_LIBM to EXPM1L_LIBM, avoiding gratuitous duplicates. case " $EXPM1L_LIBM " in *" $EXPL_LIBM "*) ;; *) EXPM1L_LIBM="$EXPM1L_LIBM $EXPL_LIBM" ;; esac dnl Append $ROUNDL_LIBM to EXPM1L_LIBM, avoiding gratuitous duplicates. case " $EXPM1L_LIBM " in *" $ROUNDL_LIBM "*) ;; *) EXPM1L_LIBM="$EXPM1L_LIBM $ROUNDL_LIBM" ;; esac dnl Append $LDEXPL_LIBM to EXPM1L_LIBM, avoiding gratuitous duplicates. case " $EXPM1L_LIBM " in *" $LDEXPL_LIBM "*) ;; *) EXPM1L_LIBM="$EXPM1L_LIBM $LDEXPL_LIBM" ;; esac fi fi AC_SUBST([EXPM1L_LIBM]) ])