-# roundf.m4 serial 4
-dnl Copyright (C) 2007 Free Software Foundation, Inc.
+# roundf.m4 serial 17
+dnl Copyright (C) 2007-2014 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_ROUNDF],
[
+ m4_divert_text([DEFAULTS], [gl_roundf_required=plain])
AC_REQUIRE([gl_MATH_H_DEFAULTS])
+
dnl Persuade glibc <math.h> to declare roundf().
AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
- AC_CHECK_DECLS([roundf], , , [#include <math.h>])
- if test "$ac_cv_have_decl_roundf" = yes; then
- gl_CHECK_MATH_LIB([ROUNDF_LIBM], [x = roundf (x);])
+
+ gl_CHECK_MATH_LIB([ROUNDF_LIBM], [x = roundf (x);],
+ [extern
+ #ifdef __cplusplus
+ "C"
+ #endif
+ float roundf (float);
+ ])
+ if test "$ROUNDF_LIBM" != missing; then
+ HAVE_ROUNDF=1
+ dnl Also check whether it's declared.
+ dnl IRIX 6.5 has roundf() in libm but doesn't declare it in <math.h>.
+ AC_CHECK_DECLS([roundf], , [HAVE_DECL_ROUNDF=0], [[#include <math.h>]])
+
+ dnl Test whether roundf() produces correct results. On mingw, for
+ dnl x = 1/2 - 2^-25, the system's roundf() returns a wrong result.
+ AC_REQUIRE([AC_PROG_CC])
+ AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+ AC_CACHE_CHECK([whether roundf works], [gl_cv_func_roundf_works],
+ [
+ save_LIBS="$LIBS"
+ LIBS="$LIBS $ROUNDF_LIBM"
+ AC_RUN_IFELSE([AC_LANG_SOURCE([[
+#include <float.h>
+#include <math.h>
+extern
+#ifdef __cplusplus
+"C"
+#endif
+float roundf (float);
+#ifdef _MSC_VER
+# pragma fenv_access (off)
+#endif
+int main()
+{
+ /* 2^FLT_MANT_DIG. */
+ static const float TWO_MANT_DIG =
+ /* Assume FLT_MANT_DIG <= 3 * 31.
+ Use the identity n = floor(n/3) + floor((n+1)/3) + floor((n+2)/3). */
+ (float) (1U << (FLT_MANT_DIG / 3))
+ * (float) (1U << ((FLT_MANT_DIG + 1) / 3))
+ * (float) (1U << ((FLT_MANT_DIG + 2) / 3));
+ volatile float x = 0.5f - 0.5f / TWO_MANT_DIG;
+ exit (x < 0.5f && roundf (x) != 0.0f);
+}]])], [gl_cv_func_roundf_works=yes], [gl_cv_func_roundf_works=no],
+ [case "$host_os" in
+ mingw*) gl_cv_func_roundf_works="guessing no";;
+ *) gl_cv_func_roundf_works="guessing yes";;
+ esac
+ ])
+ LIBS="$save_LIBS"
+ ])
+ case "$gl_cv_func_roundf_works" in
+ *no) REPLACE_ROUNDF=1 ;;
+ esac
+
+ m4_ifdef([gl_FUNC_ROUNDF_IEEE], [
+ if test $gl_roundf_required = ieee && test $REPLACE_ROUNDF = 0; then
+ AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+ AC_CACHE_CHECK([whether roundf works according to ISO C 99 with IEC 60559],
+ [gl_cv_func_roundf_ieee],
+ [
+ save_LIBS="$LIBS"
+ LIBS="$LIBS $ROUNDF_LIBM"
+ AC_RUN_IFELSE(
+ [AC_LANG_SOURCE([[
+#ifndef __NO_MATH_INLINES
+# define __NO_MATH_INLINES 1 /* for glibc */
+#endif
+#include <math.h>
+extern
+#ifdef __cplusplus
+"C"
+#endif
+float roundf (float);
+]gl_FLOAT_MINUS_ZERO_CODE[
+]gl_FLOAT_SIGNBIT_CODE[
+static float dummy (float f) { return 0; }
+int main (int argc, char *argv[])
+{
+ float (*my_roundf) (float) = argc ? roundf : dummy;
+ int result = 0;
+ /* Test whether roundf (-0.0f) is -0.0f. */
+ if (signbitf (minus_zerof) && !signbitf (my_roundf (minus_zerof)))
+ result |= 1;
+ /* Test whether roundf (-0.3f) is -0.0f. */
+ if (signbitf (-0.3f) && !signbitf (my_roundf (-0.3f)))
+ result |= 2;
+ return result;
+}
+ ]])],
+ [gl_cv_func_roundf_ieee=yes],
+ [gl_cv_func_roundf_ieee=no],
+ [case "$host_os" in
+ # Guess yes on glibc systems.
+ *-gnu*) gl_cv_func_roundf_ieee="guessing yes" ;;
+ # If we don't know, assume the worst.
+ *) gl_cv_func_roundf_ieee="guessing no" ;;
+ esac
+ ])
+ LIBS="$save_LIBS"
+ ])
+ case "$gl_cv_func_roundf_ieee" in
+ *yes) ;;
+ *) REPLACE_ROUNDF=1 ;;
+ esac
+ fi
+ ])
+ else
+ HAVE_ROUNDF=0
+ HAVE_DECL_ROUNDF=0
fi
- if test "$ac_cv_have_decl_roundf" != yes || test "$ROUNDF_LIBM" = missing; then
- REPLACE_ROUNDF=1
- AC_LIBOBJ([roundf])
- AC_CHECK_DECLS([ceilf, floorf], , , [#include <math.h>])
+ if test $HAVE_ROUNDF = 0 || test $REPLACE_ROUNDF = 1; then
+ dnl Find libraries needed to link lib/roundf.c.
+ AC_CHECK_DECLS([ceilf, floorf], , , [[#include <math.h>]])
if test "$ac_cv_have_decl_floorf" = yes \
&& test "$ac_cv_have_decl_ceilf" = yes; then
- gl_CHECK_MATH_LIB([ROUNDF_LIBM], [x = floorf (x) + ceilf (x);])
- if test "$ROUNDF_LIBM" != missing; then
- AC_DEFINE([HAVE_FLOORF_AND_CEILF], 1,
+ gl_FUNC_FLOORF_LIBS
+ gl_FUNC_CEILF_LIBS
+ if test "$FLOORF_LIBM" != '?' && test "$CEILF_LIBM" != '?'; then
+ AC_DEFINE([HAVE_FLOORF_AND_CEILF], [1],
[Define if the both the floorf() and ceilf() functions exist.])
+ ROUNDF_LIBM=
+ dnl Append $FLOORF_LIBM to ROUNDF_LIBM, avoiding gratuitous duplicates.
+ case " $ROUNDF_LIBM " in
+ *" $FLOORF_LIBM "*) ;;
+ *) ROUNDF_LIBM="$ROUNDF_LIBM $FLOORF_LIBM" ;;
+ esac
+ dnl Append $CEILF_LIBM to ROUNDF_LIBM, avoiding gratuitous duplicates.
+ case " $ROUNDF_LIBM " in
+ *" $CEILF_LIBM "*) ;;
+ *) ROUNDF_LIBM="$ROUNDF_LIBM $CEILF_LIBM" ;;
+ esac
else
ROUNDF_LIBM=
fi
projects / gnulib.git / blobdiff