-# isnand.m4 serial 2
-dnl Copyright (C) 2007-2008 Free Software Foundation, Inc.
+# isnand.m4 serial 11
+dnl Copyright (C) 2007-2013 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.
+dnl Check how to get or define isnand().
+
+AC_DEFUN([gl_FUNC_ISNAND],
+[
+ AC_REQUIRE([gl_MATH_H_DEFAULTS])
+ ISNAND_LIBM=
+ gl_HAVE_ISNAND_NO_LIBM
+ if test $gl_cv_func_isnand_no_libm = no; then
+ gl_HAVE_ISNAND_IN_LIBM
+ if test $gl_cv_func_isnand_in_libm = yes; then
+ ISNAND_LIBM=-lm
+ fi
+ fi
+ dnl The variable gl_func_isnand set here is used by isnan.m4.
+ if test $gl_cv_func_isnand_no_libm = yes \
+ || test $gl_cv_func_isnand_in_libm = yes; then
+ gl_func_isnand=yes
+ else
+ gl_func_isnand=no
+ HAVE_ISNAND=0
+ fi
+ AC_SUBST([ISNAND_LIBM])
+])
+
dnl Check how to get or define isnand() without linking with libm.
AC_DEFUN([gl_FUNC_ISNAND_NO_LIBM],
[
- AC_CACHE_CHECK([whether isnan(double) can be used without linking with libm],
- [gl_cv_func_isnand_no_libm],
- [
- AC_TRY_LINK([#include <math.h>
- #if __GNUC__ >= 4
- # undef isnand
- # define isnand(x) __builtin_isnan ((double)(x))
- #else
- # undef isnand
- # define isnand(x) isnan ((double)(x))
- #endif
- double x;],
- [return isnand (x);],
- [gl_cv_func_isnand_no_libm=yes],
- [gl_cv_func_isnand_no_libm=no])
- ])
+ gl_HAVE_ISNAND_NO_LIBM
+ gl_func_isnand_no_libm=$gl_cv_func_isnand_no_libm
if test $gl_cv_func_isnand_no_libm = yes; then
- AC_DEFINE([HAVE_ISNAND_IN_LIBC], 1,
+ AC_DEFINE([HAVE_ISNAND_IN_LIBC], [1],
[Define if the isnan(double) function is available in libc.])
- else
- AC_LIBOBJ([isnand])
- gl_DOUBLE_EXPONENT_LOCATION
fi
])
-AC_DEFUN([gl_DOUBLE_EXPONENT_LOCATION],
+dnl Prerequisites of replacement isnand definition. It does not need -lm.
+AC_DEFUN([gl_PREREQ_ISNAND],
[
- AC_CACHE_CHECK([where to find the exponent in a 'double'],
- [gl_cv_cc_double_expbit0],
+ AC_REQUIRE([gl_DOUBLE_EXPONENT_LOCATION])
+])
+
+dnl Test whether isnand() can be used with libm.
+
+AC_DEFUN([gl_HAVE_ISNAND_IN_LIBM],
+[
+ AC_CACHE_CHECK([whether isnan(double) can be used with libm],
+ [gl_cv_func_isnand_in_libm],
[
- AC_TRY_RUN([
-#include <float.h>
-#include <stddef.h>
-#include <stdio.h>
-#include <string.h>
-#define NWORDS \
- ((sizeof (double) + sizeof (unsigned int) - 1) / sizeof (unsigned int))
-typedef union { double value; unsigned int word[NWORDS]; } memory_double;
-static unsigned int ored_words[NWORDS];
-static unsigned int anded_words[NWORDS];
-static void add_to_ored_words (double x)
-{
- memory_double m;
- size_t i;
- /* Clear it first, in case sizeof (double) < sizeof (memory_double). */
- memset (&m, 0, sizeof (memory_double));
- m.value = x;
- for (i = 0; i < NWORDS; i++)
- {
- ored_words[i] |= m.word[i];
- anded_words[i] &= m.word[i];
- }
-}
-int main ()
-{
- size_t j;
- FILE *fp = fopen ("conftest.out", "w");
- if (fp == NULL)
- return 1;
- for (j = 0; j < NWORDS; j++)
- anded_words[j] = ~ (unsigned int) 0;
- add_to_ored_words (0.25);
- add_to_ored_words (0.5);
- add_to_ored_words (1.0);
- add_to_ored_words (2.0);
- add_to_ored_words (4.0);
- /* Remove bits that are common (e.g. if representation of the first mantissa
- bit is explicit). */
- for (j = 0; j < NWORDS; j++)
- ored_words[j] &= ~anded_words[j];
- /* Now find the nonzero word. */
- for (j = 0; j < NWORDS; j++)
- if (ored_words[j] != 0)
- break;
- if (j < NWORDS)
- {
- size_t i;
- for (i = j + 1; i < NWORDS; i++)
- if (ored_words[i] != 0)
- {
- fprintf (fp, "unknown");
- return (fclose (fp) != 0);
- }
- for (i = 0; ; i++)
- if ((ored_words[j] >> i) & 1)
- {
- fprintf (fp, "word %d bit %d", (int) j, (int) i);
- return (fclose (fp) != 0);
- }
- }
- fprintf (fp, "unknown");
- return (fclose (fp) != 0);
-}
- ],
- [gl_cv_cc_double_expbit0=`cat conftest.out`],
- [gl_cv_cc_double_expbit0="unknown"],
- [
- dnl On ARM, there are two 'double' floating-point formats, used by
- dnl different sets of instructions: The older FPA instructions assume
- dnl that they are stored in big-endian word order, while the words
- dnl (like integer types) are stored in little-endian byte order.
- dnl The newer VFP instructions assume little-endian order consistenly.
- AC_EGREP_CPP([mixed_endianness], [
-#if defined arm || defined __arm || defined __arm__
- mixed_endianness
-#endif
- ],
- [gl_cv_cc_double_expbit0="unknown"],
- [
- pushdef([AC_MSG_CHECKING],[:])dnl
- pushdef([AC_MSG_RESULT],[:])dnl
- pushdef([AC_MSG_RESULT_UNQUOTED],[:])dnl
- AC_C_BIGENDIAN(
- [gl_cv_cc_double_expbit0="word 0 bit 20"],
- [gl_cv_cc_double_expbit0="word 1 bit 20"],
- [gl_cv_cc_double_expbit0="unknown"])
- popdef([AC_MSG_RESULT_UNQUOTED])dnl
- popdef([AC_MSG_RESULT])dnl
- popdef([AC_MSG_CHECKING])dnl
- ])
- ])
- rm -f conftest.out
+ save_LIBS="$LIBS"
+ LIBS="$LIBS -lm"
+ AC_LINK_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <math.h>
+ #if __GNUC__ >= 4
+ # undef isnand
+ # define isnand(x) __builtin_isnan ((double)(x))
+ #elif defined isnan
+ # undef isnand
+ # define isnand(x) isnan ((double)(x))
+ #endif
+ double x;]],
+ [[return isnand (x);]])],
+ [gl_cv_func_isnand_in_libm=yes],
+ [gl_cv_func_isnand_in_libm=no])
+ LIBS="$save_LIBS"
+ ])
+])
+
+AC_DEFUN([gl_HAVE_ISNAND_NO_LIBM],
+[
+ AC_CACHE_CHECK([whether isnan(double) can be used without linking with libm],
+ [gl_cv_func_isnand_no_libm],
+ [
+ AC_LINK_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <math.h>
+ #if __GNUC__ >= 4
+ # undef isnand
+ # define isnand(x) __builtin_isnan ((double)(x))
+ #else
+ # undef isnand
+ # define isnand(x) isnan ((double)(x))
+ #endif
+ double x;]],
+ [[return isnand (x);]])],
+ [gl_cv_func_isnand_no_libm=yes],
+ [gl_cv_func_isnand_no_libm=no])
])
- case "$gl_cv_cc_double_expbit0" in
- word*bit*)
- word=`echo "$gl_cv_cc_double_expbit0" | sed -e 's/word //' -e 's/ bit.*//'`
- bit=`echo "$gl_cv_cc_double_expbit0" | sed -e 's/word.*bit //'`
- AC_DEFINE_UNQUOTED([DBL_EXPBIT0_WORD], [$word],
- [Define as the word index where to find the exponent of 'double'.])
- AC_DEFINE_UNQUOTED([DBL_EXPBIT0_BIT], [$bit],
- [Define as the bit index in the word where to find bit 0 of the exponent of 'double'.])
- ;;
- esac
])
projects / gnulib.git / blobdiff