New module 'ilogbf'.

* lib/math.in.h (ilogbf): New declaration.
* lib/ilogbf.c: New file.
* m4/ilogbf.m4: New file.
* m4/math_h.m4 (gl_MATH_H): Test whether ilogbf is declared.
(gl_MATH_H_DEFAULTS): Initialize GNULIB_ILOGBF, HAVE_ILOGBF,
REPLACE_ILOGBF.
* modules/math (Makefile.am): Substitute GNULIB_ILOGBF, HAVE_ILOGBF,
REPLACE_ILOGBF.
* modules/ilogbf: New file.
* tests/test-math-c++.cc: Check the declaration of ilogbf.
* doc/posix-functions/ilogbf.texi: Mention the new module.

9 files changed, 225 insertions, 6 deletions

diff --git a/ChangeLog b/ChangeLog
index 3e84e6dc28..efaaf640b1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,20 @@
 2012-04-03  Bruno Haible  <bruno@clisp.org>
 
+	New module 'ilogbf'.
+	* lib/math.in.h (ilogbf): New declaration.
+	* lib/ilogbf.c: New file.
+	* m4/ilogbf.m4: New file.
+	* m4/math_h.m4 (gl_MATH_H): Test whether ilogbf is declared.
+	(gl_MATH_H_DEFAULTS): Initialize GNULIB_ILOGBF, HAVE_ILOGBF,
+	REPLACE_ILOGBF.
+	* modules/math (Makefile.am): Substitute GNULIB_ILOGBF, HAVE_ILOGBF,
+	REPLACE_ILOGBF.
+	* modules/ilogbf: New file.
+	* tests/test-math-c++.cc: Check the declaration of ilogbf.
+	* doc/posix-functions/ilogbf.texi: Mention the new module.
+
+2012-04-03  Bruno Haible  <bruno@clisp.org>
+
 	Tests for module 'ilogb'.
 	* modules/ilogb-tests: New file.
 	* tests/test-ilogb.c: New file.
diff --git a/doc/posix-functions/ilogbf.texi b/doc/posix-functions/ilogbf.texi
index f496aaad9f..478cd898a9 100644
--- a/doc/posix-functions/ilogbf.texi
+++ b/doc/posix-functions/ilogbf.texi
@@ -4,15 +4,21 @@
 
 POSIX specification:@* @url{http://www.opengroup.org/onlinepubs/9699919799/functions/ilogbf.html}
 
-Gnulib module: ---
+Gnulib module: ilogbf
 
 Portability problems fixed by Gnulib:
 @itemize
+@item
+This function is missing on some platforms:
+Minix 3.1.8, AIX 5.1, HP-UX 11, IRIX 6.5, Solaris 9, MSVC 9.
+@item
+This function returns a wrong result for a zero argument on some platforms:
+OpenBSD 4.9.
+@item
+This function returns a wrong result for an infinite argument on some platforms:
+NetBSD 5.1, OpenBSD 4.9.
 @end itemize
 
 Portability problems not fixed by Gnulib:
 @itemize
-@item
-This function is missing on some platforms:
-Minix 3.1.8, AIX 5.1, HP-UX 11, IRIX 6.5, Solaris 9, MSVC 9.
 @end itemize
diff --git a/lib/ilogbf.c b/lib/ilogbf.c
new file mode 100644
index 0000000000..d6403d0423
--- /dev/null
+++ b/lib/ilogbf.c
@@ -0,0 +1,23 @@
+/* Floating-point exponent.
+   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>
+
+#define USE_FLOAT
+#include "ilogb.c"
diff --git a/lib/math.in.h b/lib/math.in.h
index 83ba3476bc..74fca3a5e4 100644
--- a/lib/math.in.h
+++ b/lib/math.in.h
@@ -1087,6 +1087,29 @@ _GL_WARN_ON_USE (hypotl, "hypotl is unportable - "
 #endif
 
 
+#if @GNULIB_ILOGBF@
+# if @REPLACE_ILOGBF@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef ilogbf
+#   define ilogbf rpl_ilogbf
+#  endif
+_GL_FUNCDECL_RPL (ilogbf, int, (float x));
+_GL_CXXALIAS_RPL (ilogbf, int, (float x));
+# else
+#  if !@HAVE_ILOGBF@
+_GL_FUNCDECL_SYS (ilogbf, int, (float x));
+#  endif
+_GL_CXXALIAS_SYS (ilogbf, int, (float x));
+# endif
+_GL_CXXALIASWARN (ilogbf);
+#elif defined GNULIB_POSIXCHECK
+# undef ilogbf
+# if HAVE_RAW_DECL_ILOGBF
+_GL_WARN_ON_USE (ilogbf, "ilogbf is unportable - "
+                 "use gnulib module ilogbf for portability");
+# endif
+#endif
+
 #if @GNULIB_ILOGB@
 # if @REPLACE_ILOGB@
 #  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
diff --git a/m4/ilogbf.m4 b/m4/ilogbf.m4
new file mode 100644
index 0000000000..1044dfa283
--- /dev/null
+++ b/m4/ilogbf.m4
@@ -0,0 +1,107 @@
+# ilogbf.m4 serial 1
+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,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_FUNC_ILOGBF],
+[
+  AC_REQUIRE([gl_MATH_H_DEFAULTS])
+
+  dnl Persuade glibc <math.h> to declare ilogbf().
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+
+  dnl Determine ILOGBF_LIBM.
+  gl_MATHFUNC([ilogbf], [int], [(float)])
+  if test $gl_cv_func_ilogbf_no_libm = yes \
+     || test $gl_cv_func_ilogbf_in_libm = yes; then
+    save_LIBS="$LIBS"
+    LIBS="$LIBS $ILOGBF_LIBM"
+    gl_FUNC_ILOGBF_WORKS
+    LIBS="$save_LIBS"
+    case "$gl_cv_func_ilogbf_works" in
+      *yes) ;;
+      *) REPLACE_ILOGBF=1 ;;
+    esac
+  else
+    HAVE_ILOGBF=0
+  fi
+  if test $HAVE_ILOGBF = 0 || test $REPLACE_ILOGBF = 1; then
+    dnl Find libraries needed to link lib/ilogbf.c.
+    AC_REQUIRE([gl_FUNC_FREXPF])
+    AC_REQUIRE([gl_FUNC_ISNANF])
+    ILOGBF_LIBM=
+    dnl Append $FREXPF_LIBM to ILOGBF_LIBM, avoiding gratuitous duplicates.
+    case " $ILOGBF_LIBM " in
+      *" $FREXPF_LIBM "*) ;;
+      *) ILOGBF_LIBM="$ILOGBF_LIBM $FREXPF_LIBM" ;;
+    esac
+    dnl Append $ISNANF_LIBM to ILOGBF_LIBM, avoiding gratuitous duplicates.
+    case " $ILOGBF_LIBM " in
+      *" $ISNANF_LIBM "*) ;;
+      *) ILOGBF_LIBM="$ILOGBF_LIBM $ISNANF_LIBM" ;;
+    esac
+  fi
+  AC_SUBST([ILOGBF_LIBM])
+])
+
+dnl Test whether ilogbf() works.
+dnl On OpenBSD 4.9, ilogbf(0.0) is wrong.
+dnl On NetBSD 5.1, OpenBSD 4.9, ilogbf(Infinity) is wrong.
+AC_DEFUN([gl_FUNC_ILOGBF_WORKS],
+[
+  AC_REQUIRE([AC_PROG_CC])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+  AC_CACHE_CHECK([whether ilogbf works], [gl_cv_func_ilogbf_works],
+    [
+      AC_RUN_IFELSE(
+        [AC_LANG_SOURCE([[
+#include <limits.h>
+#include <math.h>
+/* Provide FP_ILOGB0, FP_ILOGBNAN, like in math.in.h.  */
+#if !(defined FP_ILOGB0 && defined FP_ILOGBNAN)
+# if defined __NetBSD__ || defined __sgi
+  /* NetBSD, IRIX 6.5: match what ilogbf() does */
+#  define FP_ILOGB0   INT_MIN
+#  define FP_ILOGBNAN INT_MIN
+# elif defined _AIX
+  /* AIX 5.1: match what ilogbf() does in AIX >= 5.2 */
+#  define FP_ILOGB0   INT_MIN
+#  define FP_ILOGBNAN INT_MAX
+# elif defined __sun
+  /* Solaris 9: match what ilogbf() does */
+#  define FP_ILOGB0   (- INT_MAX)
+#  define FP_ILOGBNAN INT_MAX
+# endif
+#endif
+volatile float x;
+static float zero;
+static int dummy (float x) { return 0; }
+int main (int argc, char *argv[])
+{
+  int (*my_ilogbf) (float) = argc ? ilogbf : dummy;
+  int result = 0;
+  /* This test fails on OpenBSD 4.9.  */
+  {
+    x = 0.0f;
+    if (my_ilogbf (x) != FP_ILOGB0)
+      result |= 1;
+  }
+  /* This test fails on NetBSD 5.1, OpenBSD 4.9.  */
+  {
+    x = 1.0f / zero;
+    if (my_ilogbf (x) != INT_MAX)
+      result |= 2;
+  }
+  return result;
+}
+]])],
+        [gl_cv_func_ilogbf_works=yes],
+        [gl_cv_func_ilogbf_works=no],
+        [case "$host_os" in
+           openbsd* | netbsd*) gl_cv_func_ilogbf_works="guessing no";;
+           *)                  gl_cv_func_ilogbf_works="guessing yes";;
+         esac
+        ])
+    ])
+])
diff --git a/m4/math_h.m4 b/m4/math_h.m4
index d9735df133..c00c415d4a 100644
--- a/m4/math_h.m4
+++ b/m4/math_h.m4
@@ -1,4 +1,4 @@
-# math_h.m4 serial 111
+# math_h.m4 serial 112
 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,
@@ -44,7 +44,7 @@ AC_DEFUN([gl_MATH_H],
      expf expl exp2 exp2f exp2l expm1 expm1f expm1l
      fabsf fabsl floorf floorl fma fmaf fmal
      fmod fmodf fmodl frexpf frexpl hypotf hypotl
-     ilogb
+     ilogb ilogbf
      ldexpf ldexpl
      log logf logl log10 log10f log10l log1p log1pf log1pl log2 log2f log2l
      logb logbf logbl
@@ -110,6 +110,7 @@ AC_DEFUN([gl_MATH_H_DEFAULTS],
   GNULIB_HYPOTF=0;     AC_SUBST([GNULIB_HYPOTF])
   GNULIB_HYPOTL=0;     AC_SUBST([GNULIB_HYPOTL])
   GNULIB_ILOGB=0;      AC_SUBST([GNULIB_ILOGB])
+  GNULIB_ILOGBF=0;     AC_SUBST([GNULIB_ILOGBF])
   GNULIB_ISFINITE=0;   AC_SUBST([GNULIB_ISFINITE])
   GNULIB_ISINF=0;      AC_SUBST([GNULIB_ISINF])
   GNULIB_ISNAN=0;      AC_SUBST([GNULIB_ISNAN])
@@ -189,6 +190,7 @@ AC_DEFUN([gl_MATH_H_DEFAULTS],
   HAVE_HYPOTF=1;               AC_SUBST([HAVE_HYPOTF])
   HAVE_HYPOTL=1;               AC_SUBST([HAVE_HYPOTL])
   HAVE_ILOGB=1;                AC_SUBST([HAVE_ILOGB])
+  HAVE_ILOGBF=1;               AC_SUBST([HAVE_ILOGBF])
   HAVE_ISNANF=1;               AC_SUBST([HAVE_ISNANF])
   HAVE_ISNAND=1;               AC_SUBST([HAVE_ISNAND])
   HAVE_ISNANL=1;               AC_SUBST([HAVE_ISNANL])
@@ -280,6 +282,7 @@ AC_DEFUN([gl_MATH_H_DEFAULTS],
   REPLACE_HYPOTF=0;            AC_SUBST([REPLACE_HYPOTF])
   REPLACE_HYPOTL=0;            AC_SUBST([REPLACE_HYPOTL])
   REPLACE_ILOGB=0;             AC_SUBST([REPLACE_ILOGB])
+  REPLACE_ILOGBF=0;            AC_SUBST([REPLACE_ILOGBF])
   REPLACE_ISFINITE=0;          AC_SUBST([REPLACE_ISFINITE])
   REPLACE_ISINF=0;             AC_SUBST([REPLACE_ISINF])
   REPLACE_ISNAN=0;             AC_SUBST([REPLACE_ISNAN])
diff --git a/modules/ilogbf b/modules/ilogbf
new file mode 100644
index 0000000000..925078b6c7
--- /dev/null
+++ b/modules/ilogbf
@@ -0,0 +1,36 @@
+Description:
+ilogbf() function: get exponent as integer.
+
+Files:
+lib/ilogbf.c
+lib/ilogb.c
+m4/ilogbf.m4
+m4/mathfunc.m4
+
+Depends-on:
+math
+extensions
+isfinite        [test $HAVE_ILOGBF = 0 || test $REPLACE_ILOGBF = 1]
+frexpf          [test $HAVE_ILOGBF = 0 || test $REPLACE_ILOGBF = 1]
+isnanf          [test $HAVE_ILOGBF = 0 || test $REPLACE_ILOGBF = 1]
+
+configure.ac:
+gl_FUNC_ILOGBF
+if test $HAVE_ILOGBF = 0 || test $REPLACE_ILOGBF = 1; then
+  AC_LIBOBJ([ilogbf])
+fi
+gl_MATH_MODULE_INDICATOR([ilogbf])
+
+Makefile.am:
+
+Include:
+<math.h>
+
+Link:
+$(ILOGBF_LIBM)
+
+License:
+LGPL
+
+Maintainer:
+Bruno Haible
diff --git a/modules/math b/modules/math
index 3b7cbd66d2..a2ef168b14 100644
--- a/modules/math
+++ b/modules/math
@@ -73,6 +73,7 @@ math.h: math.in.h $(top_builddir)/config.status $(CXXDEFS_H) $(ARG_NONNULL_H) $(
 	      -e 's/@''GNULIB_HYPOTF''@/$(GNULIB_HYPOTF)/g' \
 	      -e 's/@''GNULIB_HYPOTL''@/$(GNULIB_HYPOTL)/g' \
 	      -e 's/@''GNULIB_ILOGB''@/$(GNULIB_ILOGB)/g' \
+	      -e 's/@''GNULIB_ILOGBF''@/$(GNULIB_ILOGBF)/g' \
 	      -e 's/@''GNULIB_ISFINITE''@/$(GNULIB_ISFINITE)/g' \
 	      -e 's/@''GNULIB_ISINF''@/$(GNULIB_ISINF)/g' \
 	      -e 's/@''GNULIB_ISNAN''@/$(GNULIB_ISNAN)/g' \
@@ -152,6 +153,7 @@ math.h: math.in.h $(top_builddir)/config.status $(CXXDEFS_H) $(ARG_NONNULL_H) $(
 	      -e 's|@''HAVE_HYPOTF''@|$(HAVE_HYPOTF)|g' \
 	      -e 's|@''HAVE_HYPOTL''@|$(HAVE_HYPOTL)|g' \
 	      -e 's|@''HAVE_ILOGB''@|$(HAVE_ILOGB)|g' \
+	      -e 's|@''HAVE_ILOGBF''@|$(HAVE_ILOGBF)|g' \
 	      -e 's|@''HAVE_ISNANF''@|$(HAVE_ISNANF)|g' \
 	      -e 's|@''HAVE_ISNAND''@|$(HAVE_ISNAND)|g' \
 	      -e 's|@''HAVE_ISNANL''@|$(HAVE_ISNANL)|g' \
@@ -244,6 +246,7 @@ math.h: math.in.h $(top_builddir)/config.status $(CXXDEFS_H) $(ARG_NONNULL_H) $(
 	      -e 's|@''REPLACE_HYPOTF''@|$(REPLACE_HYPOTF)|g' \
 	      -e 's|@''REPLACE_HYPOTL''@|$(REPLACE_HYPOTL)|g' \
 	      -e 's|@''REPLACE_ILOGB''@|$(REPLACE_ILOGB)|g' \
+	      -e 's|@''REPLACE_ILOGBF''@|$(REPLACE_ILOGBF)|g' \
 	      -e 's|@''REPLACE_ISFINITE''@|$(REPLACE_ISFINITE)|g' \
 	      -e 's|@''REPLACE_ISINF''@|$(REPLACE_ISINF)|g' \
 	      -e 's|@''REPLACE_ISNAN''@|$(REPLACE_ISNAN)|g' \
diff --git a/tests/test-math-c++.cc b/tests/test-math-c++.cc
index 7d1cc23f48..45fc2a3808 100644
--- a/tests/test-math-c++.cc
+++ b/tests/test-math-c++.cc
@@ -194,6 +194,9 @@ SIGNATURE_CHECK (GNULIB_NAMESPACE::hypotl, long double,
                  (long double, long double));
 #endif
 
+#if GNULIB_TEST_ILOGBF
+SIGNATURE_CHECK (GNULIB_NAMESPACE::ilogbf, int, (float));
+#endif
 #if GNULIB_TEST_ILOGB
 SIGNATURE_CHECK (GNULIB_NAMESPACE::ilogb, int, (double));
 #endif