| # exp2l.m4 serial 9 |
| dnl Copyright (C) 2010-2020 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_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 <math.h> 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 <math.h>. |
| AC_CHECK_DECL([exp2l], , [HAVE_DECL_EXP2L=0], [[#include <math.h>]]) |
| 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 <float.h> |
| #include <math.h> |
| /* Override the values of <float.h>, 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 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 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*) 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 $EXP2L_LIBM" |
| AC_RUN_IFELSE( |
| [AC_LANG_SOURCE([[ |
| #ifndef __NO_MATH_INLINES |
| # define __NO_MATH_INLINES 1 /* for glibc */ |
| #endif |
| #include <math.h> |
| #undef exp2l |
| extern |
| #ifdef __cplusplus |
| "C" |
| #endif |
| long double exp2l (long double); |
| static long double dummy (long double x) { return 0; } |
| static long double zero; |
| int main (int argc, char *argv[]) |
| { |
| long double (* volatile my_exp2l) (long double) = argc ? exp2l : dummy; |
| int result = 0; |
| /* This test fails on OpenBSD 4.9, where exp2l(NaN) = 0.0. */ |
| if (exp2l (zero / zero) == 0.0L) |
| result |= 1; |
| /* This test fails on IRIX 6.5, where exp2l(-Inf) = 1.0. */ |
| if (!(exp2l (-1.0L / zero) == 0.0L)) |
| result |= 2; |
| return result; |
| } |
| ]])], |
| [gl_cv_func_exp2l_ieee=yes], |
| [gl_cv_func_exp2l_ieee=no], |
| [case "$host_os" in |
| # Guess yes on glibc systems. |
| *-gnu* | gnu*) gl_cv_func_exp2l_ieee="guessing yes" ;; |
| # Guess yes on musl systems. |
| *-musl*) 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]) |
| ]) |
