+2007-04-06 Bruno Haible <bruno@clisp.org>
+
+ * modules/signbit: New file.
+ * lib/signbitf.c: New file.
+ * lib/signbitd.c: New file.
+ * lib/signbitl.c: New file.
+ * m4/signbit.m4: New file.
+ * lib/math_.h (gl_signbitf, gl_signbitd, gl_signbitl): New declarations.
+ (signbit): New macro.
+ * m4/math_h.m4 (gl_MATH_H_DEFAULTS): Initialize GNULIB_SIGNBIT and
+ REPLACE_SIGNBIT.
+ * modules/math (Makefile.am) Substibute also GNULIB_SIGNBIT and
+ REPLACE_FREXPL into math.h.
+
2007-04-06 Bruno Haible <bruno@clisp.org>
* modules/isnanf-nolibm-tests: New file.
* m4/isc-posix.m4: New file.
-1998-05-10 Jim Meyering <meyering@ascend.com>
\ No newline at end of file
+1998-05-10 Jim Meyering <meyering@ascend.com>
#endif
+#if @GNULIB_SIGNBIT@
+# if @REPLACE_SIGNBIT@
+# undef signbit
+extern int gl_signbitf (float arg);
+extern int gl_signbitd (double arg);
+extern int gl_signbitl (long double arg);
+# if __GNUC__ >= 2 && !__STRICT_ANSI__
+# if defined FLT_SIGNBIT_WORD && defined FLT_SIGNBIT_BIT
+# define gl_signbitf(arg) \
+ ({ union { float _value; \
+ unsigned int _word[(sizeof (float) + sizeof (unsigned int) - 1) / sizeof (unsigned int)]; \
+ } _m; \
+ _m._value = (arg); \
+ (_m._word[FLT_SIGNBIT_WORD] >> FLT_SIGNBIT_BIT) & 1; \
+ })
+# endif
+# if defined DBL_SIGNBIT_WORD && defined DBL_SIGNBIT_BIT
+# define gl_signbitd(arg) \
+ ({ union { double _value; \
+ unsigned int _word[(sizeof (double) + sizeof (unsigned int) - 1) / sizeof (unsigned int)]; \
+ } _m; \
+ _m._value = (arg); \
+ (_m._word[DBL_SIGNBIT_WORD] >> DBL_SIGNBIT_BIT) & 1; \
+ })
+# endif
+# if defined LDBL_SIGNBIT_WORD && defined LDBL_SIGNBIT_BIT
+# define gl_signbitl(arg) \
+ ({ union { long double _value; \
+ unsigned int _word[(sizeof (long double) + sizeof (unsigned int) - 1) / sizeof (unsigned int)]; \
+ } _m; \
+ _m._value = (arg); \
+ (_m._word[LDBL_SIGNBIT_WORD] >> LDBL_SIGNBIT_BIT) & 1; \
+ })
+# endif
+# endif
+# define signbit(x) \
+ (sizeof (x) == sizeof (long double) ? gl_signbitl (x) : \
+ sizeof (x) == sizeof (double) ? gl_signbitd (x) : \
+ gl_signbitf (x))
+# endif
+#elif defined GNULIB_POSIXCHECK
+ /* How to override a macro? */
+#endif
+
+
#ifdef __cplusplus
}
#endif
--- /dev/null
+/* signbit() macro: Determine the sign bit of a floating-point number.
+ 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. */
+
+#include <config.h>
+
+/* Specification. */
+#include <math.h>
+
+#include <string.h>
+#include "isnan.h"
+#include "float+.h"
+
+#undef gl_signbitd
+
+int
+gl_signbitd (double arg)
+{
+#if defined DBL_SIGNBIT_WORD && defined DBL_SIGNBIT_BIT
+# define NWORDS \
+ ((sizeof (double) + sizeof (unsigned int) - 1) / sizeof (unsigned int))
+ union { double value; unsigned int word[NWORDS]; } m;
+ m.value = arg;
+ return (m.word[DBL_SIGNBIT_WORD] >> DBL_SIGNBIT_BIT) & 1;
+#else
+ /* This does not do the right thing for NaN, but this is irrelevant for
+ most use cases. */
+ if (isnan (arg))
+ return 0;
+ if (arg < 0.0)
+ return 1;
+ else if (arg == 0.0)
+ {
+ /* Distinguish 0.0 and -0.0. */
+ static double plus_zero = 0.0;
+ double arg_mem = arg;
+ return (memcmp (&plus_zero, &arg_mem, SIZEOF_DBL) != 0);
+ }
+ else
+ return 0;
+#endif
+}
--- /dev/null
+/* signbit() macro: Determine the sign bit of a floating-point number.
+ 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. */
+
+#include <config.h>
+
+/* Specification. */
+#include <math.h>
+
+#include <string.h>
+#include "isnanf.h"
+#include "float+.h"
+
+#undef gl_signbitf
+
+int
+gl_signbitf (float arg)
+{
+#if defined FLT_SIGNBIT_WORD && defined FLT_SIGNBIT_BIT
+# define NWORDS \
+ ((sizeof (float) + sizeof (unsigned int) - 1) / sizeof (unsigned int))
+ union { float value; unsigned int word[NWORDS]; } m;
+ m.value = arg;
+ return (m.word[FLT_SIGNBIT_WORD] >> FLT_SIGNBIT_BIT) & 1;
+#else
+ /* This does not do the right thing for NaN, but this is irrelevant for
+ most use cases. */
+ if (isnanf (arg))
+ return 0;
+ if (arg < 0.0f)
+ return 1;
+ else if (arg == 0.0f)
+ {
+ /* Distinguish 0.0f and -0.0f. */
+ static float plus_zero = 0.0f;
+ float arg_mem = arg;
+ return (memcmp (&plus_zero, &arg_mem, SIZEOF_FLT) != 0);
+ }
+ else
+ return 0;
+#endif
+}
--- /dev/null
+/* signbit() macro: Determine the sign bit of a floating-point number.
+ 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. */
+
+#include <config.h>
+
+/* Specification. */
+#include <math.h>
+
+#include <string.h>
+#include "isnanl-nolibm.h"
+#include "float+.h"
+
+#undef gl_signbitl
+
+int
+gl_signbitl (long double arg)
+{
+#if defined LDBL_SIGNBIT_WORD && defined LDBL_SIGNBIT_BIT
+# define NWORDS \
+ ((sizeof (long double) + sizeof (unsigned int) - 1) / sizeof (unsigned int))
+ union { long double value; unsigned int word[NWORDS]; } m;
+ m.value = arg;
+ return (m.word[LDBL_SIGNBIT_WORD] >> LDBL_SIGNBIT_BIT) & 1;
+#else
+ /* This does not do the right thing for NaN, but this is irrelevant for
+ most use cases. */
+ if (isnanl (arg))
+ return 0;
+ if (arg < 0.0L)
+ return 1;
+ else if (arg == 0.0L)
+ {
+ /* Distinguish 0.0L and -0.0L. */
+ static long double plus_zero = 0.0L;
+ long double arg_mem = arg;
+ return (memcmp (&plus_zero, &arg_mem, SIZEOF_LDBL) != 0);
+ }
+ else
+ return 0;
+#endif
+}
AC_DEFUN([gl_MATH_H_DEFAULTS],
[
- GNULIB_FREXP=0; AC_SUBST([GNULIB_FREXP])
- GNULIB_FREXPL=0; AC_SUBST([GNULIB_FREXPL])
- GNULIB_LDEXPL=0; AC_SUBST([GNULIB_LDEXPL])
- GNULIB_MATHL=0; AC_SUBST([GNULIB_MATHL])
+ GNULIB_FREXP=0; AC_SUBST([GNULIB_FREXP])
+ GNULIB_FREXPL=0; AC_SUBST([GNULIB_FREXPL])
+ GNULIB_LDEXPL=0; AC_SUBST([GNULIB_LDEXPL])
+ GNULIB_MATHL=0; AC_SUBST([GNULIB_MATHL])
+ GNULIB_SIGNBIT=0; AC_SUBST([GNULIB_SIGNBIT])
dnl Assume proper GNU behavior unless another module says otherwise.
HAVE_DECL_ACOSL=1; AC_SUBST([HAVE_DECL_ACOSL])
HAVE_DECL_ASINL=1; AC_SUBST([HAVE_DECL_ASINL])
REPLACE_FREXP=0; AC_SUBST([REPLACE_FREXP])
REPLACE_FREXPL=0; AC_SUBST([REPLACE_FREXPL])
REPLACE_LDEXPL=0; AC_SUBST([REPLACE_LDEXPL])
+ REPLACE_SIGNBIT=0; AC_SUBST([REPLACE_SIGNBIT])
])
--- /dev/null
+# signbit.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_SIGNBIT],
+[
+ AC_REQUIRE([gl_MATH_H_DEFAULTS])
+ AC_CACHE_CHECK([for signbit macro], [gl_cv_func_signbit],
+ [
+ AC_TRY_RUN([
+#include <math.h>
+#include <string.h>
+float p0f = 0.0f;
+float m0f = -0.0f;
+double p0d = 0.0;
+double m0d = -0.0;
+long double p0l = 0.0L;
+long double m0l = -0.0L;
+int main ()
+{
+ {
+ float plus_inf = 1.0f / p0f;
+ float minus_inf = -1.0f / p0f;
+ if (!(!signbit (255.0f)
+ && signbit (-255.0f)
+ && !signbit (p0f)
+ && (memcmp (&m0f, &p0f, sizeof (float)) == 0 || signbit (m0f))
+ && !signbit (plus_inf)
+ && signbit (minus_inf)))
+ return 1;
+ }
+ {
+ double plus_inf = 1.0 / p0d;
+ double minus_inf = -1.0 / p0d;
+ if (!(!signbit (255.0)
+ && signbit (-255.0)
+ && !signbit (p0d)
+ && (memcmp (&m0d, &p0d, sizeof (double)) == 0 || signbit (m0d))
+ && !signbit (plus_inf)
+ && signbit (minus_inf)))
+ return 1;
+ }
+ {
+ long double plus_inf = 1.0L / p0l;
+ long double minus_inf = -1.0L / p0l;
+ if (!(!signbit (255.0L)
+ && signbit (-255.0L)
+ && !signbit (p0l)
+ && (memcmp (&m0l, &p0l, sizeof (long double)) == 0 || signbit (m0l))
+ && !signbit (plus_inf)
+ && signbit (minus_inf)))
+ return 1;
+ }
+ return 0;
+}], [gl_cv_func_signbit=yes], [gl_cv_func_signbit=no],
+ [gl_cv_func_signbit="guessing no"])
+ ])
+ if test "$gl_cv_func_signbit" != yes; then
+ REPLACE_SIGNBIT=1
+ AC_LIBOBJ([signbitf])
+ AC_LIBOBJ([signbitd])
+ AC_LIBOBJ([signbitl])
+ gl_FLOAT_SIGN_LOCATION
+ gl_DOUBLE_SIGN_LOCATION
+ gl_LONG_DOUBLE_SIGN_LOCATION
+ fi
+])
+
+AC_DEFUN([gl_FLOAT_SIGN_LOCATION],
+[
+ gl_FLOATTYPE_SIGN_LOCATION([float], [gl_cv_cc_float_signbit], [f], [FLT])
+])
+
+AC_DEFUN([gl_DOUBLE_SIGN_LOCATION],
+[
+ gl_FLOATTYPE_SIGN_LOCATION([double], [gl_cv_cc_double_signbit], [], [DBL])
+])
+
+AC_DEFUN([gl_LONG_DOUBLE_SIGN_LOCATION],
+[
+ gl_FLOATTYPE_SIGN_LOCATION([long double], [gl_cv_cc_long_double_signbit], [L], [LDBL])
+])
+
+AC_DEFUN([gl_FLOATTYPE_SIGN_LOCATION],
+[
+ AC_CACHE_CHECK([where to find the sign bit in a '$1'],
+ [$2],
+ [
+ AC_TRY_RUN([
+#include <stddef.h>
+#include <stdio.h>
+#define NWORDS \
+ ((sizeof ($1) + sizeof (unsigned int) - 1) / sizeof (unsigned int))
+typedef union { $1 value; unsigned int word[NWORDS]; }
+ memory_float;
+static memory_float plus = { 1.0$3 };
+static memory_float minus = { -1.0$3 };
+int main ()
+{
+ size_t j, k, i;
+ unsigned int m;
+ FILE *fp = fopen ("conftest.out", "w");
+ if (fp == NULL)
+ return 1;
+ /* Find the different bit. */
+ k = 0; m = 0;
+ for (j = 0; j < NWORDS; j++)
+ {
+ unsigned int x = plus.word[j] ^ minus.word[j];
+ if ((x & (x - 1)) || (x && m))
+ {
+ /* More than one bit difference. */
+ fprintf (fp, "unknown");
+ return 1;
+ }
+ if (x)
+ {
+ k = j;
+ m = x;
+ }
+ }
+ if (m == 0)
+ {
+ /* No difference. */
+ fprintf (fp, "unknown");
+ return 1;
+ }
+ /* Now m = plus.word[k] ^ ~minus.word[k]. */
+ if (plus.word[k] & ~minus.word[k])
+ {
+ /* Oh? The sign bit is set in the positive and cleared in the negative
+ numbers? */
+ fprintf (fp, "unknown");
+ return 1;
+ }
+ for (i = 0; ; i++)
+ if ((m >> i) & 1)
+ break;
+ fprintf (fp, "word %d bit %d", (int) k, (int) i);
+ return (fclose (fp) != 0);
+}
+ ],
+ [$2=`cat conftest.out`],
+ [$2="unknown"],
+ [
+ dnl When cross-compiling, we don't know. It depends on the
+ dnl ABI and compiler version. There are too many cases.
+ $2="unknown"
+ ])
+ rm -f conftest.out
+ ])
+ case "$]$2[" in
+ word*bit*)
+ word=`echo "$]$2[" | sed -e 's/word //' -e 's/ bit.*//'`
+ bit=`echo "$]$2[" | sed -e 's/word.*bit //'`
+ AC_DEFINE_UNQUOTED([$4][_SIGNBIT_WORD], [$word],
+ [Define as the word index where to find the sign of '$1'.])
+ AC_DEFINE_UNQUOTED([$4][_SIGNBIT_BIT], [$bit],
+ [Define as the bit index in the word where to find the sign of '$1'.])
+ ;;
+ esac
+])
-e 's|@''GNULIB_FREXPL''@|$(GNULIB_FREXPL)|g' \
-e 's|@''GNULIB_LDEXPL''@|$(GNULIB_LDEXPL)|g' \
-e 's|@''GNULIB_MATHL''@|$(GNULIB_MATHL)|g' \
+ -e 's|@''GNULIB_SIGNBIT''@|$(GNULIB_SIGNBIT)|g' \
-e 's|@''HAVE_DECL_ACOSL''@|$(HAVE_DECL_ACOSL)|g' \
-e 's|@''HAVE_DECL_ASINL''@|$(HAVE_DECL_ASINL)|g' \
-e 's|@''HAVE_DECL_ATANL''@|$(HAVE_DECL_ATANL)|g' \
-e 's|@''REPLACE_FREXP''@|$(REPLACE_FREXP)|g' \
-e 's|@''REPLACE_FREXPL''@|$(REPLACE_FREXPL)|g' \
-e 's|@''REPLACE_LDEXPL''@|$(REPLACE_LDEXPL)|g' \
+ -e 's|@''REPLACE_SIGNBIT''@|$(REPLACE_SIGNBIT)|g' \
-e '/definition of GL_LINK_WARNING/r $(LINK_WARNING_H)' \
< $(srcdir)/math_.h; \
} > $@-t
--- /dev/null
+Description:
+signbit() macro: Determine the sign bit of a floating-point number.
+
+Files:
+lib/signbitf.c
+lib/signbitd.c
+lib/signbitl.c
+lib/float+.h
+m4/signbit.m4
+
+Depends-on:
+math
+isnanf-nolibm
+isnan-nolibm
+isnanl-nolibm
+fpieee
+
+configure.ac:
+gl_SIGNBIT
+gl_MATH_MODULE_INDICATOR([signbit])
+
+Makefile.am:
+
+Include:
+<math.h>
+
+License:
+LGPL
+
+Maintainer:
+Bruno Haible
+
projects / pspp / commitdiff