New module 'floorf'.

9 files changed, 217 insertions, 4 deletions

diff --git a/ChangeLog b/ChangeLog
index 024eabc23b..d20f769eb5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,16 @@
+2007-10-04  Bruno Haible  <bruno@clisp.org>
+
+	* 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.
+
 2007-10-04  Benoit Sigoure  <tsuna@lrde.epita.fr>
             Bruno Haible  <bruno@clisp.org>
 
diff --git a/doc/functions/floorf.texi b/doc/functions/floorf.texi
index 27541b6272..a3b2301cd2 100644
--- a/doc/functions/floorf.texi
+++ b/doc/functions/floorf.texi
@@ -4,15 +4,15 @@
 
 POSIX specification: @url{http://www.opengroup.org/susv3xsh/floorf.html}
 
-Gnulib module: ---
+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
-@item
-This function is missing on some platforms:
-AIX 5.1, HP-UX 11, Solaris 9.
 @end itemize
diff --git a/lib/floor.c b/lib/floor.c
new file mode 100644
index 0000000000..0b2bb8a288
--- /dev/null
+++ b/lib/floor.c
@@ -0,0 +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 <bruno@clisp.org>, 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;
+}
diff --git a/lib/floorf.c b/lib/floorf.c
new file mode 100644
index 0000000000..769d4523ae
--- /dev/null
+++ b/lib/floorf.c
@@ -0,0 +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 <bruno@clisp.org>, 2007.  */
+
+#define USE_FLOAT
+#include "floor.c"
diff --git a/lib/math.in.h b/lib/math.in.h
index fb70011ce9..179e0c5426 100644
--- a/lib/math.in.h
+++ b/lib/math.in.h
@@ -126,6 +126,19 @@ extern long double expl (long double x);
 #endif
 
 
+#if @GNULIB_FLOORF@
+# if !@HAVE_DECL_FLOORF@
+#  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@ || !@HAVE_DECL_FLOORL@
 extern long double floorl (long double x);
 #endif
diff --git a/m4/floorf.m4 b/m4/floorf.m4
new file mode 100644
index 0000000000..184c2ee54e
--- /dev/null
+++ b/m4/floorf.m4
@@ -0,0 +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])
+])
diff --git a/m4/math_h.m4 b/m4/math_h.m4
index d9a8cc44d0..d5ef0b6827 100644
--- a/m4/math_h.m4
+++ b/m4/math_h.m4
@@ -19,6 +19,7 @@ AC_DEFUN([gl_MATH_MODULE_INDICATOR],
 
 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])
@@ -34,6 +35,7 @@ AC_DEFUN([gl_MATH_H_DEFAULTS],
   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])
diff --git a/modules/floorf b/modules/floorf
new file mode 100644
index 0000000000..47b9d5ca24
--- /dev/null
+++ b/modules/floorf
@@ -0,0 +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:
+$(FLOORF_LIBM)
+
+License:
+LGPL
+
+Maintainer:
+Bruno Haible
+
diff --git a/modules/math b/modules/math
index db0faee12e..a5ae2795cd 100644
--- a/modules/math
+++ b/modules/math
@@ -22,6 +22,7 @@ math.h: math.in.h
 	{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */' && \
 	  sed -e 's/@''INCLUDE_NEXT''@/$(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''@|$(GNULIB_LDEXPL)|g' \
@@ -36,6 +37,7 @@ math.h: math.in.h
 	      -e 's|@''HAVE_DECL_CEILL''@|$(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' \