new module 'fabsl'

[Bruno Haible]

The function fabsl() is one of those <math.h> functions that gnulib doesn't
provide so far. This patch adds it.


2012-02-25  Bruno Haible  <address@hidden>

        New module 'fabsl'.
        * lib/math.in.h (fabsl): New declaration.
        * lib/fabsl.c: New file.
        * m4/fabsl.m4: New file.
        * m4/math_h.m4 (gl_MATH_H): Test whether fabsl is declared.
        (gl_MATH_H_DEFAULTS): Initialize GNULIB_FABSL, HAVE_FABSL,
        REPLACE_FABSL.
        * modules/math (Makefile.am): Substitute GNULIB_FABSL, HAVE_FABSL,
        REPLACE_FABSL.
        * modules/fabsl: New file.
        * doc/posix-functions/fabsl.texi: Mention the new module.

================================= lib/fabsl.c =================================
/* Absolute value.
   Copyright (C) 2012 Free Software Foundation, Inc.

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#include <config.h>

/* Specification.  */
#include <math.h>

/* fabsl (x) can be defined as copysignl (x, 1.0L).
   Or, more directly, as (signbit (x) ? - x : x).  */

#if HAVE_SAME_LONG_DOUBLE_AS_DOUBLE

long double
fabsl (long double x)
{
  return fabs (x);
}

#else

long double
fabsl (long double x)
{
  return (signbit (x) ? - x : x);
}

#endif
================================= m4/fabsl.m4 =================================
# fabsl.m4 serial 1
dnl Copyright (C) 2011-2012 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.

AC_DEFUN([gl_FUNC_FABSL],
[
  AC_REQUIRE([gl_MATH_H_DEFAULTS])
  AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE])

  dnl Determine FABSL_LIBM.
  gl_MATHFUNC([fabsl], [long double], [(long double)])
  if test $gl_cv_func_fabsl_no_libm = yes \
     || test $gl_cv_func_fabsl_in_libm = yes; then
    save_LIBS="$LIBS"
    LIBS="$LIBS $FABSL_LIBM"
    gl_FUNC_FABSL_WORKS
    LIBS="$save_LIBS"
    case "$gl_cv_func_fabsl_works" in
      *yes) ;;
      *) REPLACE_FABSL=1 ;;
    esac
  else
    HAVE_FABSL=0
  fi
  if test $HAVE_FABSL = 0 || test $REPLACE_FABSL = 1; then
    dnl Find libraries needed to link lib/fabsl.c.
    if test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1; then
      AC_REQUIRE([gl_FUNC_FABS])
      FABSL_LIBM="$FABS_LIBM"
    else
      FABSL_LIBM=
    fi
  fi
  AC_SUBST([FABSL_LIBM])
])

dnl Test whether fabsl() works on a minus zero.
dnl On IRIX 6.5, with gcc 4.2.4 and without -fno-builtin-fabsl, the value is a
dnl minus zero rather than a positive zero.
AC_DEFUN([gl_FUNC_FABSL_WORKS],
[
  AC_REQUIRE([AC_PROG_CC])
  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
  AC_CACHE_CHECK([whether fabsl works], [gl_cv_func_fabsl_works],
    [
      AC_RUN_IFELSE(
        [AC_LANG_SOURCE([[
#include <float.h>
#include <math.h>
#include <string.h>
volatile long double x;
long double y;
long double zero = 0.0L;
int main ()
{
  x = - (LDBL_MIN * LDBL_MIN * LDBL_MIN);
  y = fabsl (x);
  return (memcmp (&y, &zero, sizeof y) != 0);
}
]])],
        [gl_cv_func_fabsl_works=yes],
        [gl_cv_func_fabsl_works=no],
        [case "$host_os" in
           irix*) gl_cv_func_fabsl_works="guessing no";;
           *)     gl_cv_func_fabsl_works="guessing yes";;
         esac
        ])
    ])
])
================================ modules/fabsl ================================
Description:
fabsl() function: absolute value.

Files:
lib/fabsl.c
m4/fabsl.m4
m4/mathfunc.m4

Depends-on:
math
fabs            [{ test $HAVE_FABSL = 0 || test $REPLACE_FABSL = 1; } && test 
$HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1]
signbit         [{ test $HAVE_FABSL = 0 || test $REPLACE_FABSL = 1; } && test 
$HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 0]

configure.ac:
gl_FUNC_FABSL
if test $HAVE_FABSL = 0 || test $REPLACE_FABSL = 1; then
  AC_LIBOBJ([fabsl])
fi
gl_MATH_MODULE_INDICATOR([fabsl])

Makefile.am:

Include:
<math.h>

Link:
$(FABSL_LIBM)

License:
LGPL

Maintainer:
Bruno Haible
===============================================================================
--- doc/posix-functions/fabsl.texi.orig Sat Feb 25 13:14:25 2012
+++ doc/posix-functions/fabsl.texi      Sat Feb 25 12:42:21 2012
@@ -4,18 +4,21 @@
 
 POSIX specification:@* 
@url{http://www.opengroup.org/onlinepubs/9699919799/functions/fabsl.html}
 
-Gnulib module: ---
+Gnulib module: fabsl
 
 Portability problems fixed by Gnulib:
 @itemize
address@hidden itemize
-
-Portability problems not fixed by Gnulib:
address@hidden
 @item
 This function is missing on some platforms:
 NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11, IRIX 6.5, Solaris 9, Cygwin, 
Interix 3.5, BeOS.
 @item
 This function is only defined as a macro with arguments on some platforms:
 MSVC 9.
address@hidden
+This function returns a minus zero for a minus zero argument on some platforms:
+IRIX 6.5 with gcc 4.2.4.
address@hidden itemize
+
+Portability problems not fixed by Gnulib:
address@hidden
 @end itemize
--- lib/math.in.h.orig  Sat Feb 25 13:14:25 2012
+++ lib/math.in.h       Sat Feb 25 12:57:18 2012
@@ -453,6 +453,30 @@
 # endif
 #endif
 
+#if @GNULIB_FABSL@
+# if @REPLACE_FABSL@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef fabsl
+#   define fabsl rpl_fabsl
+#  endif
+_GL_FUNCDECL_RPL (fabsl, long double, (long double x));
+_GL_CXXALIAS_RPL (fabsl, long double, (long double x));
+# else
+#  if address@hidden@
+#   undef fabsl
+_GL_FUNCDECL_SYS (fabsl, long double, (long double x));
+#  endif
+_GL_CXXALIAS_SYS (fabsl, long double, (long double x));
+# endif
+_GL_CXXALIASWARN (fabsl);
+#elif defined GNULIB_POSIXCHECK
+# undef fabsl
+# if HAVE_RAW_DECL_FABSL
+_GL_WARN_ON_USE (fabsl, "fabsl is unportable - "
+                 "use gnulib module fabsl for portability");
+# endif
+#endif
+
 
 #if @GNULIB_FLOORF@
 # if @REPLACE_FLOORF@
--- m4/math_h.m4.orig   Sat Feb 25 13:14:25 2012
+++ m4/math_h.m4        Sat Feb 25 12:57:42 2012
@@ -1,4 +1,4 @@
-# math_h.m4 serial 56
+# math_h.m4 serial 57
 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,
@@ -41,7 +41,7 @@
   gl_WARN_ON_USE_PREPARE([[#include <math.h>]],
     [acosf acosl asinf asinl atanf atanl
      ceilf ceill copysign copysignf copysignl cosf cosl coshf
-     expf expl fabsf floorf floorl fma fmaf fmal fmodf frexpf frexpl
+     expf expl fabsf fabsl floorf floorl fma fmaf fmal fmodf frexpf frexpl
      ldexpf ldexpl logb logf logl log10f modff powf
      rint rintf rintl round roundf roundl sinf sinl sinhf sqrtf sqrtl
      tanf tanl tanhf trunc truncf truncl])
@@ -77,6 +77,7 @@
   GNULIB_EXPF=0;      AC_SUBST([GNULIB_EXPF])
   GNULIB_EXPL=0;      AC_SUBST([GNULIB_EXPL])
   GNULIB_FABSF=0;     AC_SUBST([GNULIB_FABSF])
+  GNULIB_FABSL=0;     AC_SUBST([GNULIB_FABSL])
   GNULIB_FLOOR=0;     AC_SUBST([GNULIB_FLOOR])
   GNULIB_FLOORF=0;    AC_SUBST([GNULIB_FLOORF])
   GNULIB_FLOORL=0;    AC_SUBST([GNULIB_FLOORL])
@@ -136,6 +137,7 @@
   HAVE_EXPF=1;                 AC_SUBST([HAVE_EXPF])
   HAVE_EXPL=1;                 AC_SUBST([HAVE_EXPL])
   HAVE_FABSF=1;                AC_SUBST([HAVE_FABSF])
+  HAVE_FABSL=1;                AC_SUBST([HAVE_FABSL])
   HAVE_FMA=1;                  AC_SUBST([HAVE_FMA])
   HAVE_FMAF=1;                 AC_SUBST([HAVE_FMAF])
   HAVE_FMAL=1;                 AC_SUBST([HAVE_FMAL])
@@ -186,6 +188,7 @@
   REPLACE_CEIL=0;              AC_SUBST([REPLACE_CEIL])
   REPLACE_CEILF=0;             AC_SUBST([REPLACE_CEILF])
   REPLACE_CEILL=0;             AC_SUBST([REPLACE_CEILL])
+  REPLACE_FABSL=0;             AC_SUBST([REPLACE_FABSL])
   REPLACE_FLOOR=0;             AC_SUBST([REPLACE_FLOOR])
   REPLACE_FLOORF=0;            AC_SUBST([REPLACE_FLOORF])
   REPLACE_FLOORL=0;            AC_SUBST([REPLACE_FLOORL])
--- modules/math.orig   Sat Feb 25 13:14:25 2012
+++ modules/math        Sat Feb 25 12:58:07 2012
@@ -47,6 +47,7 @@
              -e 's/@''GNULIB_EXPF''@/$(GNULIB_EXPF)/g' \
              -e 's/@''GNULIB_EXPL''@/$(GNULIB_EXPL)/g' \
              -e 's/@''GNULIB_FABSF''@/$(GNULIB_FABSF)/g' \
+             -e 's/@''GNULIB_FABSL''@/$(GNULIB_FABSL)/g' \
              -e 's/@''GNULIB_FLOOR''@/$(GNULIB_FLOOR)/g' \
              -e 's/@''GNULIB_FLOORF''@/$(GNULIB_FLOORF)/g' \
              -e 's/@''GNULIB_FLOORL''@/$(GNULIB_FLOORL)/g' \
@@ -106,6 +107,7 @@
              -e 's|@''HAVE_EXPF''@|$(HAVE_EXPF)|g' \
              -e 's|@''HAVE_EXPL''@|$(HAVE_EXPL)|g' \
              -e 's|@''HAVE_FABSF''@|$(HAVE_FABSF)|g' \
+             -e 's|@''HAVE_FABSL''@|$(HAVE_FABSL)|g' \
              -e 's|@''HAVE_FMA''@|$(HAVE_FMA)|g' \
              -e 's|@''HAVE_FMAF''@|$(HAVE_FMAF)|g' \
              -e 's|@''HAVE_FMAL''@|$(HAVE_FMAL)|g' \
@@ -157,6 +159,7 @@
          sed -e 's|@''REPLACE_CEIL''@|$(REPLACE_CEIL)|g' \
              -e 's|@''REPLACE_CEILF''@|$(REPLACE_CEILF)|g' \
              -e 's|@''REPLACE_CEILL''@|$(REPLACE_CEILL)|g' \
+             -e 's|@''REPLACE_FABSL''@|$(REPLACE_FABSL)|g' \
              -e 's|@''REPLACE_FLOOR''@|$(REPLACE_FLOOR)|g' \
              -e 's|@''REPLACE_FLOORF''@|$(REPLACE_FLOORF)|g' \
              -e 's|@''REPLACE_FLOORL''@|$(REPLACE_FLOORL)|g' \