Mercurial > hg > octave-lyh > gnulib-hg
changeset 16697:6b65a767165c
sqrtl: Bypass broken implementation in OpenBSD 5.1/SPARC.
* lib/math.in.h (sqrtl): Replace it if REPLACE_SQRTL is 1.
* m4/sqrtl.m4 (gl_FUNC_SQRTL_WORKS): New macro.
(gl_FUNC_SQRTL): Invoke it. Set REPLACE_SQRTL to 1 if sqrtl() produces
too big rounding errors.
* m4/math_h.m4 (gl_MATH_H_DEFAULTS): Initialize REPLACE_SQRTL.
* modules/math (Makefile.am): Substitute REPLACE_SQRTL.
* modules/sqrtl (configure.ac): Consider REPLACE_SQRTL.
(Depends-on): Update conditions.
* tests/test-sqrtl.c (my_ldexpl): New function.
(main): Add test of a particular value.
* doc/posix-functions/sqrtl.texi: Mention the OpenBSD 5.1/SPARC bug.
author | Bruno Haible <bruno@clisp.org> |
---|---|
date | Wed, 14 Mar 2012 01:51:10 +0100 |
parents | a61aad62576e |
children | bf76aa416bc7 |
files | ChangeLog doc/posix-functions/sqrtl.texi lib/math.in.h m4/math_h.m4 m4/sqrtl.m4 modules/math modules/sqrtl tests/test-sqrtl.c |
diffstat | 8 files changed, 128 insertions(+), 11 deletions(-) [+] |
line wrap: on
line diff
--- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,18 @@ +2012-03-13 Bruno Haible <bruno@clisp.org> + + sqrtl: Bypass broken implementation in OpenBSD 5.1/SPARC. + * lib/math.in.h (sqrtl): Replace it if REPLACE_SQRTL is 1. + * m4/sqrtl.m4 (gl_FUNC_SQRTL_WORKS): New macro. + (gl_FUNC_SQRTL): Invoke it. Set REPLACE_SQRTL to 1 if sqrtl() produces + too big rounding errors. + * m4/math_h.m4 (gl_MATH_H_DEFAULTS): Initialize REPLACE_SQRTL. + * modules/math (Makefile.am): Substitute REPLACE_SQRTL. + * modules/sqrtl (configure.ac): Consider REPLACE_SQRTL. + (Depends-on): Update conditions. + * tests/test-sqrtl.c (my_ldexpl): New function. + (main): Add test of a particular value. + * doc/posix-functions/sqrtl.texi: Mention the OpenBSD 5.1/SPARC bug. + 2012-03-13 Pádraig Brady <P@draigBrady.com> doc: Update timer_* platform portability notes.
--- a/doc/posix-functions/sqrtl.texi +++ b/doc/posix-functions/sqrtl.texi @@ -17,6 +17,9 @@ @item This function is not declared on some platforms: MacOS X 10.3. +@item +This function produces very imprecise results on some platforms: +OpenBSD 5.1/SPARC. @end itemize Portability problems not fixed by Gnulib:
--- a/lib/math.in.h +++ b/lib/math.in.h @@ -1698,11 +1698,20 @@ #endif #if @GNULIB_SQRTL@ -# if !@HAVE_SQRTL@ || !@HAVE_DECL_SQRTL@ -# undef sqrtl +# if @REPLACE_SQRTL@ +# if !(defined __cplusplus && defined GNULIB_NAMESPACE) +# undef sqrtl +# define sqrtl rpl_sqrtl +# endif +_GL_FUNCDECL_RPL (sqrtl, long double, (long double x)); +_GL_CXXALIAS_RPL (sqrtl, long double, (long double x)); +# else +# if !@HAVE_SQRTL@ || !@HAVE_DECL_SQRTL@ +# undef sqrtl _GL_FUNCDECL_SYS (sqrtl, long double, (long double x)); +# endif +_GL_CXXALIAS_SYS (sqrtl, long double, (long double x)); # endif -_GL_CXXALIAS_SYS (sqrtl, long double, (long double x)); _GL_CXXALIASWARN (sqrtl); #elif defined GNULIB_POSIXCHECK # undef sqrtl
--- a/m4/math_h.m4 +++ b/m4/math_h.m4 @@ -1,4 +1,4 @@ -# math_h.m4 serial 103 +# math_h.m4 serial 104 dnl Copyright (C) 2007-2012 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, @@ -295,6 +295,7 @@ REPLACE_ROUNDL=0; AC_SUBST([REPLACE_ROUNDL]) REPLACE_SIGNBIT=0; AC_SUBST([REPLACE_SIGNBIT]) REPLACE_SIGNBIT_USING_GCC=0; AC_SUBST([REPLACE_SIGNBIT_USING_GCC]) + REPLACE_SQRTL=0; AC_SUBST([REPLACE_SQRTL]) REPLACE_TRUNC=0; AC_SUBST([REPLACE_TRUNC]) REPLACE_TRUNCF=0; AC_SUBST([REPLACE_TRUNCF]) REPLACE_TRUNCL=0; AC_SUBST([REPLACE_TRUNCL])
--- a/m4/sqrtl.m4 +++ b/m4/sqrtl.m4 @@ -1,4 +1,4 @@ -# sqrtl.m4 serial 7 +# sqrtl.m4 serial 8 dnl Copyright (C) 2010-2012 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, @@ -58,9 +58,20 @@ dnl Also check whether it's declared. dnl MacOS X 10.3 has sqrtl() in libc but doesn't declare it in <math.h>. AC_CHECK_DECL([sqrtl], , [HAVE_DECL_SQRTL=0], [[#include <math.h>]]) + + save_LIBS="$LIBS" + LIBS="$LIBS $SQRTL_LIBM" + gl_FUNC_SQRTL_WORKS + LIBS="$save_LIBS" + case "$gl_cv_func_sqrtl_works" in + *yes) ;; + *) REPLACE_SQRTL=1 ;; + esac else HAVE_DECL_SQRTL=0 HAVE_SQRTL=0 + fi + if test $HAVE_SQRTL = 0 || test $REPLACE_SQRTL = 1; then dnl Find libraries needed to link lib/sqrtl.c. if test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1; then AC_REQUIRE([gl_FUNC_SQRT]) @@ -94,3 +105,56 @@ fi AC_SUBST([SQRTL_LIBM]) ]) + +dnl Test whether sqrtl() works. +dnl On OpenBSD 5.1/SPARC, sqrtl(8.1974099812331540680810141969554806865L) has +dnl rounding errors that eat up the last 8 to 9 decimal digits. +AC_DEFUN([gl_FUNC_SQRTL_WORKS], +[ + AC_REQUIRE([AC_PROG_CC]) + AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles + AC_CACHE_CHECK([whether sqrtl works], [gl_cv_func_sqrtl_works], + [ + AC_RUN_IFELSE( + [AC_LANG_SOURCE([[ +#include <float.h> +#include <math.h> +extern +#ifdef __cplusplus +"C" +#endif +long double sqrtl (long double); +static long double +my_ldexpl (long double x, int d) +{ + for (; d > 0; d--) + x *= 2.0L; + for (; d < 0; d++) + x *= 0.5L; + return x; +} +volatile long double x; +volatile long double y; +long double z; +int main () +{ + x = 8.1974099812331540680810141969554806865L; + y = sqrtl (x); + z = y * y - x; + z = my_ldexpl (z, LDBL_MANT_DIG); + if (z < 0) + z = - z; + if (z > 100.0L) + return 1; + return 0; +} +]])], + [gl_cv_func_sqrtl_works=yes], + [gl_cv_func_sqrtl_works=no], + [case "$host_os" in + osf*) gl_cv_func_sqrtl_works="guessing no";; + *) gl_cv_func_sqrtl_works="guessing yes";; + esac + ]) + ]) +])
--- a/modules/math +++ b/modules/math @@ -262,6 +262,7 @@ -e 's|@''REPLACE_ROUNDL''@|$(REPLACE_ROUNDL)|g' \ -e 's|@''REPLACE_SIGNBIT''@|$(REPLACE_SIGNBIT)|g' \ -e 's|@''REPLACE_SIGNBIT_USING_GCC''@|$(REPLACE_SIGNBIT_USING_GCC)|g' \ + -e 's|@''REPLACE_SQRTL''@|$(REPLACE_SQRTL)|g' \ -e 's|@''REPLACE_TRUNC''@|$(REPLACE_TRUNC)|g' \ -e 's|@''REPLACE_TRUNCF''@|$(REPLACE_TRUNCF)|g' \ -e 's|@''REPLACE_TRUNCL''@|$(REPLACE_TRUNCL)|g' \
--- a/modules/sqrtl +++ b/modules/sqrtl @@ -8,15 +8,15 @@ Depends-on: math extensions -sqrt [test $HAVE_SQRTL = 0] -float [test $HAVE_SQRTL = 0 && test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 0] -isnanl [test $HAVE_SQRTL = 0 && test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 0] -frexpl [test $HAVE_SQRTL = 0 && test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 0] -ldexpl [test $HAVE_SQRTL = 0 && test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 0] +sqrt [{ test $HAVE_SQRTL = 0 || test $REPLACE_SQRTL = 1; }] +float [{ test $HAVE_SQRTL = 0 || test $REPLACE_SQRTL = 1; } && test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 0] +isnanl [{ test $HAVE_SQRTL = 0 || test $REPLACE_SQRTL = 1; } && test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 0] +frexpl [{ test $HAVE_SQRTL = 0 || test $REPLACE_SQRTL = 1; } && test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 0] +ldexpl [{ test $HAVE_SQRTL = 0 || test $REPLACE_SQRTL = 1; } && test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 0] configure.ac: gl_FUNC_SQRTL -if test $HAVE_SQRTL = 0; then +if test $HAVE_SQRTL = 0 || test $REPLACE_SQRTL = 1; then AC_LIBOBJ([sqrtl]) fi gl_MATH_MODULE_INDICATOR([sqrtl])
--- a/tests/test-sqrtl.c +++ b/tests/test-sqrtl.c @@ -35,6 +35,16 @@ #define RANDOM randoml #include "test-sqrt.h" +static long double +my_ldexpl (long double x, int d) +{ + for (; d > 0; d--) + x *= 2.0L; + for (; d < 0; d++) + x *= 0.5L; + return x; +} + int main () { @@ -47,6 +57,20 @@ y = sqrtl (x); ASSERT (y >= 0.7745966692L && y <= 0.7745966693L); + /* Another particular value. */ + { + long double z; + long double err; + + x = 8.1974099812331540680810141969554806865L; + y = sqrtl (x); + z = y * y - x; + err = my_ldexpl (z, LDBL_MANT_DIG); + if (err < 0) + err = - err; + ASSERT (err <= 100.0L); + } + test_function (); return 0;