new module 'floorf'

[Bruno Haible]

floorf() is much like truncf().

2007-10-04  Bruno Haible  <address@hidden>

        * modules/floorf: New file.
        * lib/floor.c: New file.
        * lib/floorf.c: New file.
        * m4/floorf.m4: New file.
        * lib/math.in.h (floorf): New declaration.
        * m4/math_h.m4 (gl_MATH_H_DEFAULTS): Initialize GNULIB_FLOORF and
        HAVE_DECL_FLOORF.
        * modules/math (Makefile.am): Substitute also GNULIB_FLOORF and
        HAVE_DECL_FLOORF.
        * doc/functions/floorf.texi: Mention the 'floorf' module.

*** doc/functions/floorf.texi.orig      2007-10-05 02:59:52.000000000 +0200
--- doc/functions/floorf.texi   2007-10-05 02:42:40.000000000 +0200
***************
*** 4,18 ****
  
  POSIX specification: @url{http://www.opengroup.org/susv3xsh/floorf.html}
  
! Gnulib module: ---
  
  Portability problems fixed by Gnulib:
  @itemize
  @end itemize
  
  Portability problems not fixed by Gnulib:
  @itemize
- @item
- This function is missing on some platforms:
- AIX 5.1, HP-UX 11, Solaris 9.
  @end itemize
--- 4,18 ----
  
  POSIX specification: @url{http://www.opengroup.org/susv3xsh/floorf.html}
  
! Gnulib module: floorf
  
  Portability problems fixed by Gnulib:
  @itemize
+ @item
+ This function is missing on some platforms:
+ AIX 5.1, HP-UX 11, Solaris 9.
  @end itemize
  
  Portability problems not fixed by Gnulib:
  @itemize
  @end itemize
Changing permissions from . to 100644
*** lib/floor.c.orig    2003-09-23 19:59:22.000000000 +0200
--- lib/floor.c 2007-10-05 02:56:36.000000000 +0200
***************
*** 0 ****
--- 1,83 ----
+ /* Round towards negative infinity.
+    Copyright (C) 2007 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 2, 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, write to the Free Software Foundation,
+    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+ 
+ /* Written by Bruno Haible <address@hidden>, 2007.  */
+ 
+ #include <config.h>
+ 
+ /* Specification.  */
+ #include <math.h>
+ 
+ #include <float.h>
+ 
+ #ifdef USE_LONG_DOUBLE
+ # define FUNC floorl
+ # define DOUBLE long double
+ # define MANT_DIG LDBL_MANT_DIG
+ # define L_(literal) literal##L
+ #elif ! defined USE_FLOAT
+ # define FUNC floor
+ # define DOUBLE double
+ # define MANT_DIG DBL_MANT_DIG
+ # define L_(literal) literal
+ #else /* defined USE_FLOAT */
+ # define FUNC floorf
+ # define DOUBLE float
+ # define MANT_DIG FLT_MANT_DIG
+ # define L_(literal) literal##f
+ #endif
+ 
+ /* 2^(MANT_DIG-1).  */
+ static const double TWO_MANT_DIG =
+   /* Assume MANT_DIG <= 5 * 31.
+      Use the identity
+        n = floor(n/5) + floor((n+1)/5) + ... + floor((n+4)/5).  */
+   (DOUBLE) (1U << ((MANT_DIG - 1) / 5))
+   * (DOUBLE) (1U << ((MANT_DIG - 1 + 1) / 5))
+   * (DOUBLE) (1U << ((MANT_DIG - 1 + 2) / 5))
+   * (DOUBLE) (1U << ((MANT_DIG - 1 + 3) / 5))
+   * (DOUBLE) (1U << ((MANT_DIG - 1 + 4) / 5));
+ 
+ DOUBLE
+ FUNC (DOUBLE x)
+ {
+   /* The use of 'volatile' guarantees that excess precision bits are dropped
+      at each addition step and before the following comparison at the caller's
+      site.  It is necessary on x86 systems where double-floats are not IEEE
+      compliant by default, to avoid that the results become platform and 
compiler
+      option dependent.  'volatile' is a portable alternative to gcc's
+      -ffloat-store option.  */
+   volatile DOUBLE y = x;
+   volatile DOUBLE z = y;
+ 
+   /* Round to the next integer (nearest or up or down, doesn't matter).  */
+   if (z > L_(0.0))
+     {
+       z += TWO_MANT_DIG;
+       z -= TWO_MANT_DIG;
+     }
+   else if (z < L_(0.0))
+     {
+       z -= TWO_MANT_DIG;
+       z += TWO_MANT_DIG;
+     }
+   /* Enforce rounding down.  */
+   if (z > y)
+     z -= L_(1.0);
+ 
+   return z;
+ }
Changing permissions from . to 100644
*** lib/floorf.c.orig   2003-09-23 19:59:22.000000000 +0200
--- lib/floorf.c        2007-10-05 02:37:48.000000000 +0200
***************
*** 0 ****
--- 1,21 ----
+ /* Round towards negative infinity.
+    Copyright (C) 2007 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 2, 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, write to the Free Software Foundation,
+    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+ 
+ /* Written by Bruno Haible <address@hidden>, 2007.  */
+ 
+ #define USE_FLOAT
+ #include "floor.c"
*** lib/math.in.h.orig  2007-10-05 02:59:52.000000000 +0200
--- lib/math.in.h       2007-10-05 02:41:04.000000000 +0200
***************
*** 126,131 ****
--- 126,144 ----
  #endif
  
  
+ #if @GNULIB_FLOORF@
+ # if address@hidden@
+ #  define floorf rpl_floorf
+ extern float floorf (float x);
+ # endif
+ #elif defined GNULIB_POSIXCHECK
+ # undef floorf
+ # define floorf(x) \
+     (GL_LINK_WARNING ("floorf is unportable - " \
+                       "use gnulib module floorf for portability"), \
+      floorf (x))
+ #endif
+ 
  #if @GNULIB_MATHL@ || address@hidden@
  extern long double floorl (long double x);
  #endif
Changing permissions from . to 100644
*** m4/floorf.m4.orig   2003-09-23 19:59:22.000000000 +0200
--- m4/floorf.m4        2007-10-05 02:56:49.000000000 +0200
***************
*** 0 ****
--- 1,48 ----
+ # floorf.m4 serial 1
+ dnl Copyright (C) 2007 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_FLOORF],
+ [
+   AC_REQUIRE([gl_MATH_H_DEFAULTS])
+   dnl Persuade glibc <math.h> to declare floorf().
+   AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+   dnl Test whether floorf() is declared.
+   AC_CHECK_DECLS([floorf], , , [#include <math.h>])
+   if test "$ac_cv_have_decl_floorf" = yes; then
+     dnl Test whether floorf() can be used without libm.
+     FLOORF_LIBM=?
+     AC_TRY_LINK([
+        #ifndef __NO_MATH_INLINES
+        # define __NO_MATH_INLINES 1 /* for glibc */
+        #endif
+        #include <math.h>
+        float x;],
+       [x = floorf(x);],
+       [FLOORF_LIBM=])
+     if test "$FLOORF_LIBM" = "?"; then
+       save_LIBS="$LIBS"
+       LIBS="$LIBS -lm"
+       AC_TRY_LINK([
+          #ifndef __NO_MATH_INLINES
+          # define __NO_MATH_INLINES 1 /* for glibc */
+          #endif
+          #include <math.h>
+          float x;],
+         [x = floorf(x);],
+         [FLOORF_LIBM="-lm"])
+       LIBS="$save_LIBS"
+     fi
+     if test "$FLOORF_LIBM" = "?"; then
+       FLOORF_LIBM=
+     fi
+   else
+     HAVE_DECL_FLOORF=0
+     AC_LIBOBJ([floorf])
+     FLOORF_LIBM=
+   fi
+   AC_SUBST([HAVE_DECL_FLOORF])
+   AC_SUBST([FLOORF_LIBM])
+ ])
*** m4/math_h.m4.orig   2007-10-05 02:59:52.000000000 +0200
--- m4/math_h.m4        2007-10-05 02:41:52.000000000 +0200
***************
*** 19,24 ****
--- 19,25 ----
  
  AC_DEFUN([gl_MATH_H_DEFAULTS],
  [
+   GNULIB_FLOORF=0;  AC_SUBST([GNULIB_FLOORF])
    GNULIB_FREXP=0;   AC_SUBST([GNULIB_FREXP])
    GNULIB_FREXPL=0;  AC_SUBST([GNULIB_FREXPL])
    GNULIB_LDEXPL=0;  AC_SUBST([GNULIB_LDEXPL])
***************
*** 34,39 ****
--- 35,41 ----
    HAVE_DECL_CEILL=1;  AC_SUBST([HAVE_DECL_CEILL])
    HAVE_DECL_COSL=1;   AC_SUBST([HAVE_DECL_COSL])
    HAVE_DECL_EXPL=1;   AC_SUBST([HAVE_DECL_EXPL])
+   HAVE_DECL_FLOORF=1; AC_SUBST([HAVE_DECL_FLOORF])
    HAVE_DECL_FLOORL=1; AC_SUBST([HAVE_DECL_FLOORL])
    HAVE_DECL_FREXPL=1; AC_SUBST([HAVE_DECL_FREXPL])
    HAVE_DECL_LDEXPL=1; AC_SUBST([HAVE_DECL_LDEXPL])
Changing permissions from . to 100644
*** modules/floorf.orig 2003-09-23 19:59:22.000000000 +0200
--- modules/floorf      2007-10-05 02:33:18.000000000 +0200
***************
*** 0 ****
--- 1,31 ----
+ Description:
+ floorf() function: round towards negative infinity.
+ 
+ Files:
+ lib/floorf.c
+ lib/floor.c
+ m4/floorf.m4
+ 
+ Depends-on:
+ math
+ extensions
+ float
+ 
+ configure.ac:
+ gl_FUNC_FLOORF
+ gl_MATH_MODULE_INDICATOR([floorf])
+ 
+ Makefile.am:
+ 
+ Include:
+ <math.h>
+ 
+ Link:
+ $(FLOORF_LIBM)
+ 
+ License:
+ LGPL
+ 
+ Maintainer:
+ Bruno Haible
+ 
*** modules/math.orig   2007-10-05 02:59:52.000000000 +0200
--- modules/math        2007-10-05 02:42:25.000000000 +0200
***************
*** 22,27 ****
--- 22,28 ----
        { echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */' && \
          sed -e 's/@''INCLUDE_NEXT''@/$(INCLUDE_NEXT)/g' \
              -e 's|@''NEXT_MATH_H''@|$(NEXT_MATH_H)|g' \
+             -e 's|@''GNULIB_FLOORF''@|$(GNULIB_FLOORF)|g' \
              -e 's|@''GNULIB_FREXP''@|$(GNULIB_FREXP)|g' \
              -e 's|@''GNULIB_FREXPL''@|$(GNULIB_FREXPL)|g' \
              -e 's|@''GNULIB_LDEXPL''@|$(GNULIB_LDEXPL)|g' \
***************
*** 36,41 ****
--- 37,43 ----
              -e 's|@''HAVE_DECL_CEILL''@|$(HAVE_DECL_CEILL)|g' \
              -e 's|@''HAVE_DECL_COSL''@|$(HAVE_DECL_COSL)|g' \
              -e 's|@''HAVE_DECL_EXPL''@|$(HAVE_DECL_EXPL)|g' \
+             -e 's|@''HAVE_DECL_FLOORF''@|$(HAVE_DECL_FLOORF)|g' \
              -e 's|@''HAVE_DECL_FLOORL''@|$(HAVE_DECL_FLOORL)|g' \
              -e 's|@''HAVE_DECL_FREXPL''@|$(HAVE_DECL_FREXPL)|g' \
              -e 's|@''HAVE_DECL_LDEXPL''@|$(HAVE_DECL_LDEXPL)|g' \