# log1pl.m4 serial 10 dnl Copyright (C) 2012-2023 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_LOG1PL], [ m4_divert_text([DEFAULTS], [gl_log1pl_required=plain]) AC_REQUIRE([gl_MATH_H_DEFAULTS]) AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE]) AC_REQUIRE([gl_FUNC_LOG1P]) dnl Persuade glibc to declare log1pl(). AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS]) dnl Test whether log1pl() exists. Assume that log1pl(), if it exists, is dnl defined in the same library as log1p(). save_LIBS="$LIBS" LIBS="$LIBS $LOG1P_LIBM" AC_CHECK_FUNCS([log1pl]) LIBS="$save_LIBS" if test $ac_cv_func_log1pl = yes; then LOG1PL_LIBM="$LOG1P_LIBM" save_LIBS="$LIBS" LIBS="$LIBS $LOG1PL_LIBM" gl_FUNC_LOG1PL_WORKS LIBS="$save_LIBS" case "$gl_cv_func_log1pl_works" in *yes) ;; *) REPLACE_LOG1PL=1 ;; esac m4_ifdef([gl_FUNC_LOG1PL_IEEE], [ if test $gl_log1pl_required = ieee && test $REPLACE_LOG1PL = 0; then AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles AC_CACHE_CHECK([whether log1pl works according to ISO C 99 with IEC 60559], [gl_cv_func_log1pl_ieee], [ save_LIBS="$LIBS" LIBS="$LIBS $LOG1PL_LIBM" AC_RUN_IFELSE( [AC_LANG_SOURCE([[ #ifndef __NO_MATH_INLINES # define __NO_MATH_INLINES 1 /* for glibc */ #endif #include ]gl_LONG_DOUBLE_MINUS_ZERO_CODE[ ]gl_LONG_DOUBLE_SIGNBIT_CODE[ static long double dummy (long double x) { return 0; } int main (int argc, char *argv[]) { long double (* volatile my_log1pl) (long double) = argc ? log1pl : dummy; /* This test fails on AIX 7.1, IRIX 6.5. */ long double y = my_log1pl (minus_zerol); if (!(y == 0.0L) || (signbitl (minus_zerol) && !signbitl (y))) return 1; return 0; } ]])], [gl_cv_func_log1pl_ieee=yes], [gl_cv_func_log1pl_ieee=no], [case "$host_os" in # Guess yes on glibc systems. *-gnu* | gnu*) gl_cv_func_log1pl_ieee="guessing yes" ;; # Guess yes on musl systems. *-musl* | midipix*) gl_cv_func_log1pl_ieee="guessing yes" ;; # Guess yes on native Windows. mingw*) gl_cv_func_log1pl_ieee="guessing yes" ;; # If we don't know, obey --enable-cross-guesses. *) gl_cv_func_log1pl_ieee="$gl_cross_guess_normal" ;; esac ]) LIBS="$save_LIBS" ]) case "$gl_cv_func_log1pl_ieee" in *yes) ;; *) REPLACE_LOG1PL=1 ;; esac fi ]) else HAVE_LOG1PL=0 dnl Find libraries needed to link lib/log1pl.c. if test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1; then LOG1PL_LIBM="$LOG1P_LIBM" else AC_REQUIRE([gl_FUNC_ISNANL]) AC_REQUIRE([gl_FUNC_LOGL]) AC_REQUIRE([gl_FUNC_ROUNDL]) LOG1PL_LIBM= dnl Append $ISNANL_LIBM to LOG1PL_LIBM, avoiding gratuitous duplicates. case " $LOG1PL_LIBM " in *" $ISNANL_LIBM "*) ;; *) LOG1PL_LIBM="$LOG1PL_LIBM $ISNANL_LIBM" ;; esac dnl Append $LOGL_LIBM to LOG1PL_LIBM, avoiding gratuitous duplicates. case " $LOG1PL_LIBM " in *" $LOGL_LIBM "*) ;; *) LOG1PL_LIBM="$LOG1PL_LIBM $LOGL_LIBM" ;; esac dnl Append $ROUNDL_LIBM to LOG1PL_LIBM, avoiding gratuitous duplicates. case " $LOG1PL_LIBM " in *" $ROUNDL_LIBM "*) ;; *) LOG1PL_LIBM="$LOG1PL_LIBM $ROUNDL_LIBM" ;; esac fi fi AC_SUBST([LOG1PL_LIBM]) ]) dnl Test whether log1pl() works. dnl On musl 1.2.2/{arm64,s390x}, the result is accurate to only 16 digits. AC_DEFUN([gl_FUNC_LOG1PL_WORKS], [ AC_REQUIRE([AC_PROG_CC]) AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles AC_CACHE_CHECK([whether log1pl works], [gl_cv_func_log1pl_works], [ 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 log1pl extern #ifdef __cplusplus "C" #endif long double log1pl (long double); static long double dummy (long double x) { return 0; } int main (int argc, char *argv[]) { long double (* volatile my_log1pl) (long double) = argc ? log1pl : dummy; int result = 0; /* This test fails on musl 1.2.2/arm64, musl 1.2.2/s390x. */ { 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_log1pl (x); long double z = my_log1pl (- x / (1.0L + x)); long double err = (y + z) * TWO_LDBL_MANT_DIG; if (!(err >= -900.0L && err <= 900.0L)) result |= 1; } return result; } ]])], [gl_cv_func_log1pl_works=yes], [gl_cv_func_log1pl_works=no], [case "$host_os" in # Guess yes on glibc systems. *-gnu* | gnu*) gl_cv_func_log1pl_works="guessing yes" ;; # Guess no on musl systems. *-musl* | midipix*) gl_cv_func_log1pl_works="guessing no" ;; # Guess yes on native Windows. mingw*) gl_cv_func_log1pl_works="guessing yes" ;; # If we don't know, obey --enable-cross-guesses. *) gl_cv_func_log1pl_works="$gl_cross_guess_normal" ;; esac ]) ]) ])