-# signbit.m4 serial 7
-dnl Copyright (C) 2007-2010 Free Software Foundation, Inc.
+# signbit.m4 serial 11
+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,
dnl with or without modifications, as long as this notice is preserved.
REPLACE_SIGNBIT_USING_GCC=1
else
if test "$gl_cv_func_signbit" != yes; then
+ dnl REPLACE_SIGNBIT=1 makes sure the signbit[fdl] functions get built.
REPLACE_SIGNBIT=1
- AC_LIBOBJ([signbitf])
- AC_LIBOBJ([signbitd])
- AC_LIBOBJ([signbitl])
gl_FLOAT_SIGN_LOCATION
gl_DOUBLE_SIGN_LOCATION
gl_LONG_DOUBLE_SIGN_LOCATION
if test "$gl_cv_cc_float_signbit" = unknown; then
dnl Test whether copysignf() is declared.
- AC_CHECK_DECLS([copysignf], , , [#include <math.h>])
+ AC_CHECK_DECLS([copysignf], , , [[#include <math.h>]])
if test "$ac_cv_have_decl_copysignf" = yes; then
dnl Test whether copysignf() can be used without libm.
AC_CACHE_CHECK([whether copysignf can be used without linking with libm],
fi
if test "$gl_cv_cc_double_signbit" = unknown; then
dnl Test whether copysign() is declared.
- AC_CHECK_DECLS([copysign], , , [#include <math.h>])
+ AC_CHECK_DECLS([copysign], , , [[#include <math.h>]])
if test "$ac_cv_have_decl_copysign" = yes; then
dnl Test whether copysign() can be used without libm.
AC_CACHE_CHECK([whether copysign can be used without linking with libm],
fi
if test "$gl_cv_cc_long_double_signbit" = unknown; then
dnl Test whether copysignl() is declared.
- AC_CHECK_DECLS([copysignl], , , [#include <math.h>])
+ AC_CHECK_DECLS([copysignl], , , [[#include <math.h>]])
if test "$ac_cv_have_decl_copysignl" = yes; then
dnl Test whether copysignl() can be used without libm.
AC_CACHE_CHECK([whether copysignl can be used without linking with libm],
#else
long double m0l = -p0l;
#endif
- if (signbit (vf))
+ int result = 0;
+ if (signbit (vf)) /* link check */
vf++;
{
float plus_inf = 1.0f / p0f;
&& (memcmp (&m0f, &p0f, sizeof (float)) == 0 || signbit (m0f))
&& !signbit (plus_inf)
&& signbit (minus_inf)))
- return 1;
+ result |= 1;
}
- if (signbit (vd))
+ if (signbit (vd)) /* link check */
vd++;
{
double plus_inf = 1.0 / p0d;
&& (memcmp (&m0d, &p0d, sizeof (double)) == 0 || signbit (m0d))
&& !signbit (plus_inf)
&& signbit (minus_inf)))
- return 1;
+ result |= 2;
}
- if (signbit (vl))
+ if (signbit (vl)) /* link check */
vl++;
{
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;
+ if (signbit (255.0L))
+ result |= 4;
+ if (!signbit (-255.0L))
+ result |= 4;
+ if (signbit (p0l))
+ result |= 8;
+ if (!(memcmp (&m0l, &p0l, sizeof (long double)) == 0 || signbit (m0l)))
+ result |= 16;
+ if (signbit (plus_inf))
+ result |= 32;
+ if (!signbit (minus_inf))
+ result |= 64;
}
- return 0;
+ return result;
}
]])
{
/* More than one bit difference. */
fprintf (fp, "unknown");
- return 1;
+ return 2;
}
if (x)
{
{
/* No difference. */
fprintf (fp, "unknown");
- return 1;
+ return 3;
}
/* 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;
+ return 4;
}
for (i = 0; ; i++)
if ((m >> i) & 1)
break;
fprintf (fp, "word %d bit %d", (int) k, (int) i);
- return (fclose (fp) != 0);
+ if (fclose (fp) != 0)
+ return 5;
+ return 0;
}
]])],
[$2=`cat conftest.out`],
;;
esac
])
+
+# Expands to code that defines a function signbitf(float).
+# It extracts the sign bit of a non-NaN value.
+AC_DEFUN([gl_FLOAT_SIGNBIT_CODE],
+[
+ gl_FLOATTYPE_SIGNBIT_CODE([float], [f], [f])
+])
+
+# Expands to code that defines a function signbitd(double).
+# It extracts the sign bit of a non-NaN value.
+AC_DEFUN([gl_DOUBLE_SIGNBIT_CODE],
+[
+ gl_FLOATTYPE_SIGNBIT_CODE([double], [d], [])
+])
+
+# Expands to code that defines a function signbitl(long double).
+# It extracts the sign bit of a non-NaN value.
+AC_DEFUN([gl_LONG_DOUBLE_SIGNBIT_CODE],
+[
+ gl_FLOATTYPE_SIGNBIT_CODE([long double], [l], [L])
+])
+
+AC_DEFUN([gl_FLOATTYPE_SIGNBIT_CODE],
+[[
+static int
+signbit$2 ($1 value)
+{
+ typedef union { $1 f; unsigned char b[sizeof ($1)]; } float_union;
+ static float_union plus_one = { 1.0$3 }; /* unused bits are zero here */
+ static float_union minus_one = { -1.0$3 }; /* unused bits are zero here */
+ /* Compute the sign bit mask as the XOR of plus_one and minus_one. */
+ float_union u;
+ unsigned int i;
+ u.f = value;
+ for (i = 0; i < sizeof ($1); i++)
+ if (u.b[i] & (plus_one.b[i] ^ minus_one.b[i]))
+ return 1;
+ return 0;
+}
+]])