>From 67df3cffac300d320307e8d7e494029098edc334 Mon Sep 17 00:00:00 2001 From: Bruno Haible Date: Sun, 20 Jan 2019 22:28:37 +0100 Subject: [PATCH 3/6] expm1l: Work around inaccurate implementation on NetBSD. * lib/math.in.h (expm1l): Test also REPLACE_EXPM1L. * m4/expm1l.m4 (gl_FUNC_EXPM1L): Add test for a certain accuracy. Set REPLACE_EXPM1L. * m4/math_h.m4 (gl_MATH_H_DEFAULTS): Initialize REPLACE_EXPM1L. * modules/math (Makefile.in): Substitute REPLACE_EXPM1L. * modules/expm1l (Depends-on, configure.ac): Test REPLACE_EXPM1L. * doc/posix-functions/expm1l.texi: Mention the NetBSD bug. --- ChangeLog | 11 +++++ doc/posix-functions/expm1l.texi | 4 ++ lib/math.in.h | 15 +++++-- m4/expm1l.m4 | 94 ++++++++++++++++++++++++++++++++++++++++- m4/math_h.m4 | 3 +- modules/expm1l | 14 +++--- modules/math | 1 + 7 files changed, 130 insertions(+), 12 deletions(-) diff --git a/ChangeLog b/ChangeLog index 80f00e2..07f3cc4 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,16 @@ 2019-01-20 Bruno Haible + expm1l: Work around inaccurate implementation on NetBSD. + * lib/math.in.h (expm1l): Test also REPLACE_EXPM1L. + * m4/expm1l.m4 (gl_FUNC_EXPM1L): Add test for a certain accuracy. Set + REPLACE_EXPM1L. + * m4/math_h.m4 (gl_MATH_H_DEFAULTS): Initialize REPLACE_EXPM1L. + * modules/math (Makefile.in): Substitute REPLACE_EXPM1L. + * modules/expm1l (Depends-on, configure.ac): Test REPLACE_EXPM1L. + * doc/posix-functions/expm1l.texi: Mention the NetBSD bug. + +2019-01-20 Bruno Haible + expl: Work around inaccurate implementation on NetBSD. * lib/math.in.h (expl): Test also REPLACE_EXPL. * m4/expl.m4 (gl_FUNC_EXPL): Add test for a certain accuracy. Set diff --git a/doc/posix-functions/expm1l.texi b/doc/posix-functions/expm1l.texi index 3ccf9b1..75534f2 100644 --- a/doc/posix-functions/expm1l.texi +++ b/doc/posix-functions/expm1l.texi @@ -14,6 +14,10 @@ FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, older IRIX @item This function is not declared on some platforms: IRIX 6.5. address@hidden +This function produces results which are accurate to only 16 digits on some +platforms: +NetBSD 8.0. @end itemize Portability problems not fixed by Gnulib: diff --git a/lib/math.in.h b/lib/math.in.h index c5f9b46..270caaf 100644 --- a/lib/math.in.h +++ b/lib/math.in.h @@ -760,11 +760,20 @@ _GL_WARN_ON_USE (expm1, "expm1 is unportable - " #endif #if @GNULIB_EXPM1L@ -# if address@hidden@ -# undef expm1l +# if @REPLACE_EXPM1L@ +# if !(defined __cplusplus && defined GNULIB_NAMESPACE) +# undef expm1l +# define expm1l rpl_expm1l +# endif +_GL_FUNCDECL_RPL (expm1l, long double, (long double x)); +_GL_CXXALIAS_RPL (expm1l, long double, (long double x)); +# else +# if address@hidden@ +# undef expm1l _GL_FUNCDECL_SYS (expm1l, long double, (long double x)); -# endif +# endif _GL_CXXALIAS_SYS (expm1l, long double, (long double x)); +# endif _GL_CXXALIASWARN (expm1l); #elif defined GNULIB_POSIXCHECK # undef expm1l diff --git a/m4/expm1l.m4 b/m4/expm1l.m4 index d074550..d2307f2 100644 --- a/m4/expm1l.m4 +++ b/m4/expm1l.m4 @@ -1,4 +1,4 @@ -# expm1l.m4 serial 2 +# expm1l.m4 serial 3 dnl Copyright (C) 2010-2019 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, @@ -69,9 +69,101 @@ AC_DEFUN([gl_FUNC_EXPM1L], 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 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); + long double err = (y + (1.0L + y) * z) * 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 yes on native Windows. + mingw*) gl_cv_func_expm1l_works="guessing yes" ;; + # If we don't know, assume the worst. + *) gl_cv_func_expm1l_works="guessing no" ;; + 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]) diff --git a/m4/math_h.m4 b/m4/math_h.m4 index 2eec8c4..bbbe5d4 100644 --- a/m4/math_h.m4 +++ b/m4/math_h.m4 @@ -1,4 +1,4 @@ -# math_h.m4 serial 117 +# math_h.m4 serial 118 dnl Copyright (C) 2007-2019 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, @@ -271,6 +271,7 @@ AC_DEFUN([gl_MATH_H_DEFAULTS], REPLACE_EXPL=0; AC_SUBST([REPLACE_EXPL]) REPLACE_EXPM1=0; AC_SUBST([REPLACE_EXPM1]) REPLACE_EXPM1F=0; AC_SUBST([REPLACE_EXPM1F]) + REPLACE_EXPM1L=0; AC_SUBST([REPLACE_EXPM1L]) REPLACE_EXP2=0; AC_SUBST([REPLACE_EXP2]) REPLACE_EXP2L=0; AC_SUBST([REPLACE_EXP2L]) REPLACE_FABSL=0; AC_SUBST([REPLACE_FABSL]) diff --git a/modules/expm1l b/modules/expm1l index 1f23a0d..f7137e2 100644 --- a/modules/expm1l +++ b/modules/expm1l @@ -8,16 +8,16 @@ m4/expm1l.m4 Depends-on: math extensions -expm1 [test $HAVE_EXPM1L = 0 && test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1] -float [test $HAVE_EXPM1L = 0 && test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 0] -isnanl [test $HAVE_EXPM1L = 0 && test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 0] -expl [test $HAVE_EXPM1L = 0 && test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 0] -roundl [test $HAVE_EXPM1L = 0 && test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 0] -ldexpl [test $HAVE_EXPM1L = 0 && test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 0] +expm1 [{ test $HAVE_EXPM1L = 0 || test $REPLACE_EXPM1L = 1; } && test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1] +float [{ test $HAVE_EXPM1L = 0 || test $REPLACE_EXPM1L = 1; } && test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 0] +isnanl [{ test $HAVE_EXPM1L = 0 || test $REPLACE_EXPM1L = 1; } && test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 0] +expl [{ test $HAVE_EXPM1L = 0 || test $REPLACE_EXPM1L = 1; } && test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 0] +roundl [{ test $HAVE_EXPM1L = 0 || test $REPLACE_EXPM1L = 1; } && test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 0] +ldexpl [{ test $HAVE_EXPM1L = 0 || test $REPLACE_EXPM1L = 1; } && test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 0] configure.ac: gl_FUNC_EXPM1L -if test $HAVE_EXPM1L = 0; then +if test $HAVE_EXPM1L = 0 || test $REPLACE_EXPM1L = 1; then AC_LIBOBJ([expm1l]) fi gl_MATH_MODULE_INDICATOR([expm1l]) diff --git a/modules/math b/modules/math index 77197e5..1f23a17 100644 --- a/modules/math +++ b/modules/math @@ -240,6 +240,7 @@ math.h: math.in.h $(top_builddir)/config.status $(CXXDEFS_H) $(ARG_NONNULL_H) $( -e 's|@''REPLACE_EXPL''@|$(REPLACE_EXPL)|g' \ -e 's|@''REPLACE_EXPM1''@|$(REPLACE_EXPM1)|g' \ -e 's|@''REPLACE_EXPM1F''@|$(REPLACE_EXPM1F)|g' \ + -e 's|@''REPLACE_EXPM1L''@|$(REPLACE_EXPM1L)|g' \ -e 's|@''REPLACE_EXP2''@|$(REPLACE_EXP2)|g' \ -e 's|@''REPLACE_EXP2L''@|$(REPLACE_EXP2L)|g' \ -e 's|@''REPLACE_FABSL''@|$(REPLACE_FABSL)|g' \ -- 2.7.4