changeset 16764:d48f227b07b4

New module 'ilogb'. * lib/math.in.h (ilogb): New declaration. * lib/ilogb.c: New file. * m4/ilogb.m4: New file. * m4/math_h.m4 (gl_MATH_H): Test whether ilogb is declared. (gl_MATH_H_DEFAULTS): Initialize GNULIB_ILOGB, HAVE_ILOGB, REPLACE_ILOGB. * modules/math (Makefile.am): Substitute GNULIB_ILOGB, HAVE_ILOGB, REPLACE_ILOGB. * modules/ilogb: New file. * tests/test-math-c++.cc: Check the declaration of ilogb. * doc/posix-functions/ilogb.texi: Mention the new module.
author Bruno Haible <bruno@clisp.org>
date Tue, 03 Apr 2012 18:59:33 +0200
parents a56cad559c24
children f3fe07944aae
files ChangeLog doc/posix-functions/ilogb.texi lib/ilogb.c lib/math.in.h m4/ilogb.m4 m4/math_h.m4 modules/ilogb modules/math tests/test-math-c++.cc
diffstat 9 files changed, 278 insertions(+), 5 deletions(-) [+]
line wrap: on
line diff
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,18 @@
+2012-04-03  Bruno Haible  <bruno@clisp.org>
+
+	New module 'ilogb'.
+	* lib/math.in.h (ilogb): New declaration.
+	* lib/ilogb.c: New file.
+	* m4/ilogb.m4: New file.
+	* m4/math_h.m4 (gl_MATH_H): Test whether ilogb is declared.
+	(gl_MATH_H_DEFAULTS): Initialize GNULIB_ILOGB, HAVE_ILOGB,
+	REPLACE_ILOGB.
+	* modules/math (Makefile.am): Substitute GNULIB_ILOGB, HAVE_ILOGB,
+	REPLACE_ILOGB.
+	* modules/ilogb: New file.
+	* tests/test-math-c++.cc: Check the declaration of ilogb.
+	* doc/posix-functions/ilogb.texi: Mention the new module.
+
 2012-04-03  Bruno Haible  <bruno@clisp.org>
 
 	math: Provide FP_ILOGB0 and FP_ILOGBNAN.
--- a/doc/posix-functions/ilogb.texi
+++ b/doc/posix-functions/ilogb.texi
@@ -4,15 +4,24 @@
 
 POSIX specification:@* @url{http://www.opengroup.org/onlinepubs/9699919799/functions/ilogb.html}
 
-Gnulib module: ---
+Gnulib module: ilogb
 
 Portability problems fixed by Gnulib:
 @itemize
+@item
+This function is missing on some platforms:
+Minix 3.1.8, IRIX 5.3, MSVC 9.
+@item
+This function returns a wrong result for a zero argument on some platforms:
+OpenBSD 4.9, AIX 5.1.
+@item
+This function returns a wrong result for an infinite argument on some platforms:
+NetBSD 5.1, OpenBSD 4.9.
+@item
+This function returns a wrong result for a NaN argument on some platforms:
+OpenBSD 4.9.
 @end itemize
 
 Portability problems not fixed by Gnulib:
 @itemize
-@item
-This function is missing on some platforms:
-Minix 3.1.8, IRIX 5.3, MSVC 9.
 @end itemize
new file mode 100644
--- /dev/null
+++ b/lib/ilogb.c
@@ -0,0 +1,68 @@
+/* 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/>.  */
+
+#if ! (defined USE_LONG_DOUBLE || defined USE_FLOAT)
+# include <config.h>
+#endif
+
+/* Specification.  */
+#include <math.h>
+
+#include <limits.h>
+
+#ifdef USE_LONG_DOUBLE
+# define ILOGB ilogbl
+# define DOUBLE long double
+# define L_(literal) literal##L
+# define FREXP frexpl
+# define ISNAN isnanl
+#elif ! defined USE_FLOAT
+# define ILOGB ilogb
+# define DOUBLE double
+# define L_(literal) literal
+# define FREXP frexp
+# define ISNAN isnand
+#else /* defined USE_FLOAT */
+# define ILOGB ilogbf
+# define DOUBLE float
+# define L_(literal) literal##f
+# define FREXP frexpf
+# define ISNAN isnanf
+#endif
+
+int
+ILOGB (DOUBLE x)
+{
+  if (isfinite (x))
+    {
+      if (x == L_(0.0))
+        return FP_ILOGB0;
+      else
+        {
+          int e;
+
+          (void) FREXP (x, &e);
+          return e - 1;
+        }
+    }
+  else
+    {
+      if (ISNAN (x))
+        return FP_ILOGBNAN;
+      else
+        return INT_MAX;
+    }
+}
--- a/lib/math.in.h
+++ b/lib/math.in.h
@@ -1087,6 +1087,30 @@
 #endif
 
 
+#if @GNULIB_ILOGB@
+# if @REPLACE_ILOGB@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef ilogb
+#   define ilogb rpl_ilogb
+#  endif
+_GL_FUNCDECL_RPL (ilogb, int, (double x));
+_GL_CXXALIAS_RPL (ilogb, int, (double x));
+# else
+#  if !@HAVE_ILOGB@
+_GL_FUNCDECL_SYS (ilogb, int, (double x));
+#  endif
+_GL_CXXALIAS_SYS (ilogb, int, (double x));
+# endif
+_GL_CXXALIASWARN (ilogb);
+#elif defined GNULIB_POSIXCHECK
+# undef ilogb
+# if HAVE_RAW_DECL_ILOGB
+_GL_WARN_ON_USE (ilogb, "ilogb is unportable - "
+                 "use gnulib module ilogb for portability");
+# endif
+#endif
+
+
 /* Return x * 2^exp.  */
 #if @GNULIB_LDEXPF@
 # if !@HAVE_LDEXPF@
new file mode 100644
--- /dev/null
+++ b/m4/ilogb.m4
@@ -0,0 +1,112 @@
+# ilogb.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_ILOGB],
+[
+  AC_REQUIRE([gl_MATH_H_DEFAULTS])
+
+  dnl Determine ILOGB_LIBM.
+  gl_MATHFUNC([ilogb], [int], [(double)])
+  if test $gl_cv_func_ilogb_no_libm = yes \
+     || test $gl_cv_func_ilogb_in_libm = yes; then
+    save_LIBS="$LIBS"
+    LIBS="$LIBS $ILOGB_LIBM"
+    gl_FUNC_ILOGB_WORKS
+    LIBS="$save_LIBS"
+    case "$gl_cv_func_ilogb_works" in
+      *yes) ;;
+      *) REPLACE_ILOGB=1 ;;
+    esac
+  else
+    HAVE_ILOGB=0
+  fi
+  if test $HAVE_ILOGB = 0 || test $REPLACE_ILOGB = 1; then
+    dnl Find libraries needed to link lib/ilogb.c.
+    AC_REQUIRE([gl_FUNC_FREXP])
+    AC_REQUIRE([gl_FUNC_ISNAND])
+    ILOGB_LIBM=
+    dnl Append $FREXP_LIBM to ILOGB_LIBM, avoiding gratuitous duplicates.
+    case " $ILOGB_LIBM " in
+      *" $FREXP_LIBM "*) ;;
+      *) ILOGB_LIBM="$ILOGB_LIBM $FREXP_LIBM" ;;
+    esac
+    dnl Append $ISNAND_LIBM to ILOGB_LIBM, avoiding gratuitous duplicates.
+    case " $ILOGB_LIBM " in
+      *" $ISNAND_LIBM "*) ;;
+      *) ILOGB_LIBM="$ILOGB_LIBM $ISNAND_LIBM" ;;
+    esac
+  fi
+  AC_SUBST([ILOGB_LIBM])
+])
+
+dnl Test whether ilogb() works.
+dnl On OpenBSD 4.9, AIX 5.1, ilogb(0.0) is wrong.
+dnl On NetBSD 5.1, OpenBSD 4.9, ilogb(Infinity) is wrong.
+dnl On OpenBSD 4.9, ilogb(NaN) is wrong.
+AC_DEFUN([gl_FUNC_ILOGB_WORKS],
+[
+  AC_REQUIRE([AC_PROG_CC])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+  AC_CACHE_CHECK([whether ilogb works], [gl_cv_func_ilogb_works],
+    [
+      AC_RUN_IFELSE(
+        [AC_LANG_SOURCE([[
+#include <limits.h>
+#include <math.h>
+/* Provide FP_ILOGB0, FP_ILOGBNAN, like in math.in.h.  */
+#if !(defined FP_ILOGB0 && defined FP_ILOGBNAN)
+# if defined __NetBSD__ || defined __sgi
+  /* NetBSD, IRIX 6.5: match what ilogb() does */
+#  define FP_ILOGB0   INT_MIN
+#  define FP_ILOGBNAN INT_MIN
+# elif defined _AIX
+  /* AIX 5.1: match what ilogb() does in AIX >= 5.2 */
+#  define FP_ILOGB0   INT_MIN
+#  define FP_ILOGBNAN INT_MAX
+# elif defined __sun
+  /* Solaris 9: match what ilogb() does */
+#  define FP_ILOGB0   (- INT_MAX)
+#  define FP_ILOGBNAN INT_MAX
+# endif
+#endif
+volatile double x;
+static double zero;
+static int dummy (double x) { return 0; }
+int main (int argc, char *argv[])
+{
+  int (*my_ilogb) (double) = argc ? ilogb : dummy;
+  int result = 0;
+  /* This test fails on OpenBSD 4.9, AIX 5.1.  */
+  {
+    x = 0.0;
+    if (my_ilogb (x) != FP_ILOGB0)
+      result |= 1;
+  }
+  /* This test fails on NetBSD 5.1, OpenBSD 4.9.  */
+  {
+    x = 1.0 / zero;
+    if (my_ilogb (x) != INT_MAX)
+      result |= 2;
+  }
+  /* This test fails on OpenBSD 4.9.  */
+  {
+    x = zero / zero;
+    if (my_ilogb (x) != FP_ILOGBNAN)
+      result |= 4;
+  }
+  return result;
+}
+]])],
+        [gl_cv_func_ilogb_works=yes],
+        [gl_cv_func_ilogb_works=no],
+        [case "$host_os" in
+           aix* | openbsd* | netbsd* | solaris*)
+              gl_cv_func_ilogb_works="guessing no";;
+           *) gl_cv_func_ilogb_works="guessing yes";;
+         esac
+        ])
+    ])
+])
--- a/m4/math_h.m4
+++ b/m4/math_h.m4
@@ -1,4 +1,4 @@
-# math_h.m4 serial 110
+# math_h.m4 serial 111
 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,
@@ -44,6 +44,7 @@
      expf expl exp2 exp2f exp2l expm1 expm1f expm1l
      fabsf fabsl floorf floorl fma fmaf fmal
      fmod fmodf fmodl frexpf frexpl hypotf hypotl
+     ilogb
      ldexpf ldexpl
      log logf logl log10 log10f log10l log1p log1pf log1pl log2 log2f log2l
      logb logbf logbl
@@ -108,6 +109,7 @@
   GNULIB_HYPOT=0;      AC_SUBST([GNULIB_HYPOT])
   GNULIB_HYPOTF=0;     AC_SUBST([GNULIB_HYPOTF])
   GNULIB_HYPOTL=0;     AC_SUBST([GNULIB_HYPOTL])
+  GNULIB_ILOGB=0;      AC_SUBST([GNULIB_ILOGB])
   GNULIB_ISFINITE=0;   AC_SUBST([GNULIB_ISFINITE])
   GNULIB_ISINF=0;      AC_SUBST([GNULIB_ISINF])
   GNULIB_ISNAN=0;      AC_SUBST([GNULIB_ISNAN])
@@ -186,6 +188,7 @@
   HAVE_FREXPF=1;               AC_SUBST([HAVE_FREXPF])
   HAVE_HYPOTF=1;               AC_SUBST([HAVE_HYPOTF])
   HAVE_HYPOTL=1;               AC_SUBST([HAVE_HYPOTL])
+  HAVE_ILOGB=1;                AC_SUBST([HAVE_ILOGB])
   HAVE_ISNANF=1;               AC_SUBST([HAVE_ISNANF])
   HAVE_ISNAND=1;               AC_SUBST([HAVE_ISNAND])
   HAVE_ISNANL=1;               AC_SUBST([HAVE_ISNANL])
@@ -276,6 +279,7 @@
   REPLACE_HYPOT=0;             AC_SUBST([REPLACE_HYPOT])
   REPLACE_HYPOTF=0;            AC_SUBST([REPLACE_HYPOTF])
   REPLACE_HYPOTL=0;            AC_SUBST([REPLACE_HYPOTL])
+  REPLACE_ILOGB=0;             AC_SUBST([REPLACE_ILOGB])
   REPLACE_ISFINITE=0;          AC_SUBST([REPLACE_ISFINITE])
   REPLACE_ISINF=0;             AC_SUBST([REPLACE_ISINF])
   REPLACE_ISNAN=0;             AC_SUBST([REPLACE_ISNAN])
new file mode 100644
--- /dev/null
+++ b/modules/ilogb
@@ -0,0 +1,34 @@
+Description:
+ilogb() function: get exponent as integer.
+
+Files:
+lib/ilogb.c
+m4/ilogb.m4
+m4/mathfunc.m4
+
+Depends-on:
+math
+isfinite        [test $HAVE_ILOGB = 0 || test $REPLACE_ILOGB = 1]
+frexp           [test $HAVE_ILOGB = 0 || test $REPLACE_ILOGB = 1]
+isnand          [test $HAVE_ILOGB = 0 || test $REPLACE_ILOGB = 1]
+
+configure.ac:
+gl_FUNC_ILOGB
+if test $HAVE_ILOGB = 0 || test $REPLACE_ILOGB = 1; then
+  AC_LIBOBJ([ilogb])
+fi
+gl_MATH_MODULE_INDICATOR([ilogb])
+
+Makefile.am:
+
+Include:
+<math.h>
+
+Link:
+$(ILOGB_LIBM)
+
+License:
+LGPL
+
+Maintainer:
+Bruno Haible
--- a/modules/math
+++ b/modules/math
@@ -72,6 +72,7 @@
 	      -e 's/@''GNULIB_HYPOT''@/$(GNULIB_HYPOT)/g' \
 	      -e 's/@''GNULIB_HYPOTF''@/$(GNULIB_HYPOTF)/g' \
 	      -e 's/@''GNULIB_HYPOTL''@/$(GNULIB_HYPOTL)/g' \
+	      -e 's/@''GNULIB_ILOGB''@/$(GNULIB_ILOGB)/g' \
 	      -e 's/@''GNULIB_ISFINITE''@/$(GNULIB_ISFINITE)/g' \
 	      -e 's/@''GNULIB_ISINF''@/$(GNULIB_ISINF)/g' \
 	      -e 's/@''GNULIB_ISNAN''@/$(GNULIB_ISNAN)/g' \
@@ -150,6 +151,7 @@
 	      -e 's|@''HAVE_FREXPF''@|$(HAVE_FREXPF)|g' \
 	      -e 's|@''HAVE_HYPOTF''@|$(HAVE_HYPOTF)|g' \
 	      -e 's|@''HAVE_HYPOTL''@|$(HAVE_HYPOTL)|g' \
+	      -e 's|@''HAVE_ILOGB''@|$(HAVE_ILOGB)|g' \
 	      -e 's|@''HAVE_ISNANF''@|$(HAVE_ISNANF)|g' \
 	      -e 's|@''HAVE_ISNAND''@|$(HAVE_ISNAND)|g' \
 	      -e 's|@''HAVE_ISNANL''@|$(HAVE_ISNANL)|g' \
@@ -241,6 +243,7 @@
 	      -e 's|@''REPLACE_HYPOT''@|$(REPLACE_HYPOT)|g' \
 	      -e 's|@''REPLACE_HYPOTF''@|$(REPLACE_HYPOTF)|g' \
 	      -e 's|@''REPLACE_HYPOTL''@|$(REPLACE_HYPOTL)|g' \
+	      -e 's|@''REPLACE_ILOGB''@|$(REPLACE_ILOGB)|g' \
 	      -e 's|@''REPLACE_ISFINITE''@|$(REPLACE_ISFINITE)|g' \
 	      -e 's|@''REPLACE_ISINF''@|$(REPLACE_ISINF)|g' \
 	      -e 's|@''REPLACE_ISNAN''@|$(REPLACE_ISNAN)|g' \
--- a/tests/test-math-c++.cc
+++ b/tests/test-math-c++.cc
@@ -194,6 +194,10 @@
                  (long double, long double));
 #endif
 
+#if GNULIB_TEST_ILOGB
+SIGNATURE_CHECK (GNULIB_NAMESPACE::ilogb, int, (double));
+#endif
+
 //SIGNATURE_CHECK (GNULIB_NAMESPACE::j0, double, (double));
 
 //SIGNATURE_CHECK (GNULIB_NAMESPACE::j1, double, (double));