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author | Ludovic Courtès <ludo@gnu.org> | 2012-07-06 23:25:57 +0200 |
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committer | Ludovic Courtès <ludo@gnu.org> | 2012-07-06 23:25:57 +0200 |
commit | 005de2e8273853e155c21767b1c8bdb4f3f3ca53 (patch) | |
tree | 1f215bb57b2bc61926e3d27357f7c43e993e73b9 /m4/round.m4 | |
parent | 32299e49e83b941082bee348c993630bb455a324 (diff) | |
download | guile-005de2e8273853e155c21767b1c8bdb4f3f3ca53.tar.gz |
Update Gnulib to v0.0-7509-g98a2286.
* Makefile.am (EXTRA_DIST): Add `m4/gnulib-cache.m4'.
* build-aux/git-version-gen: Keep unchanged.
Diffstat (limited to 'm4/round.m4')
-rw-r--r-- | m4/round.m4 | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/m4/round.m4 b/m4/round.m4 new file mode 100644 index 000000000..514c4f73e --- /dev/null +++ b/m4/round.m4 @@ -0,0 +1,142 @@ +# round.m4 serial 16 +dnl Copyright (C) 2007, 2009-2012 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_ROUND], +[ + m4_divert_text([DEFAULTS], [gl_round_required=plain]) + AC_REQUIRE([gl_MATH_H_DEFAULTS]) + + dnl Persuade glibc <math.h> to declare round(). + AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS]) + + gl_CHECK_MATH_LIB([ROUND_LIBM], [x = round (x);], + [extern + #ifdef __cplusplus + "C" + #endif + double round (double); + ]) + if test "$ROUND_LIBM" != missing; then + HAVE_ROUND=1 + dnl Also check whether it's declared. + dnl IRIX 6.5 has round() in libm but doesn't declare it in <math.h>. + AC_CHECK_DECLS([round], , [HAVE_DECL_ROUND=0], [[#include <math.h>]]) + + dnl Test whether round() produces correct results. On NetBSD 3.0, for + dnl x = 1/2 - 2^-54, the system's round() returns a wrong result. + AC_REQUIRE([AC_PROG_CC]) + AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles + AC_CACHE_CHECK([whether round works], [gl_cv_func_round_works], + [ + save_LIBS="$LIBS" + LIBS="$LIBS $ROUND_LIBM" + AC_RUN_IFELSE([AC_LANG_SOURCE([[ +#include <float.h> +#include <math.h> +extern +#ifdef __cplusplus +"C" +#endif +double round (double); +#ifdef _MSC_VER +# pragma fenv_access (off) +#endif +int main() +{ + /* 2^DBL_MANT_DIG. */ + static const double TWO_MANT_DIG = + /* Assume DBL_MANT_DIG <= 5 * 31. + Use the identity + n = floor(n/5) + floor((n+1)/5) + ... + floor((n+4)/5). */ + (double) (1U << (DBL_MANT_DIG / 5)) + * (double) (1U << ((DBL_MANT_DIG + 1) / 5)) + * (double) (1U << ((DBL_MANT_DIG + 2) / 5)) + * (double) (1U << ((DBL_MANT_DIG + 3) / 5)) + * (double) (1U << ((DBL_MANT_DIG + 4) / 5)); + volatile double x = 0.5 - 0.5 / TWO_MANT_DIG; + exit (x < 0.5 && round (x) != 0.0); +}]])], [gl_cv_func_round_works=yes], [gl_cv_func_round_works=no], + [case "$host_os" in + netbsd* | aix*) gl_cv_func_round_works="guessing no";; + *) gl_cv_func_round_works="guessing yes";; + esac + ]) + LIBS="$save_LIBS" + ]) + case "$gl_cv_func_round_works" in + *no) REPLACE_ROUND=1 ;; + esac + + m4_ifdef([gl_FUNC_ROUND_IEEE], [ + if test $gl_round_required = ieee && test $REPLACE_ROUND = 0; then + AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles + AC_CACHE_CHECK([whether round works according to ISO C 99 with IEC 60559], + [gl_cv_func_round_ieee], + [ + save_LIBS="$LIBS" + LIBS="$LIBS $ROUND_LIBM" + AC_RUN_IFELSE( + [AC_LANG_SOURCE([[ +#ifndef __NO_MATH_INLINES +# define __NO_MATH_INLINES 1 /* for glibc */ +#endif +#include <math.h> +extern +#ifdef __cplusplus +"C" +#endif +double round (double); +]gl_DOUBLE_MINUS_ZERO_CODE[ +]gl_DOUBLE_SIGNBIT_CODE[ +static double dummy (double f) { return 0; } +int main (int argc, char *argv[]) +{ + double (*my_round) (double) = argc ? round : dummy; + /* Test whether round (-0.0) is -0.0. */ + if (signbitd (minus_zerod) && !signbitd (my_round (minus_zerod))) + return 1; + return 0; +} + ]])], + [gl_cv_func_round_ieee=yes], + [gl_cv_func_round_ieee=no], + [case "$host_os" in + # Guess yes on glibc systems. + *-gnu*) gl_cv_func_round_ieee="guessing yes" ;; + # If we don't know, assume the worst. + *) gl_cv_func_round_ieee="guessing no" ;; + esac + ]) + LIBS="$save_LIBS" + ]) + case "$gl_cv_func_round_ieee" in + *yes) ;; + *) REPLACE_ROUND=1 ;; + esac + fi + ]) + else + HAVE_ROUND=0 + HAVE_DECL_ROUND=0 + fi + if test $HAVE_ROUND = 0 || test $REPLACE_ROUND = 1; then + dnl Find libraries needed to link lib/round.c. + gl_FUNC_FLOOR_LIBS + gl_FUNC_CEIL_LIBS + ROUND_LIBM= + dnl Append $FLOOR_LIBM to ROUND_LIBM, avoiding gratuitous duplicates. + case " $ROUND_LIBM " in + *" $FLOOR_LIBM "*) ;; + *) ROUND_LIBM="$ROUND_LIBM $FLOOR_LIBM" ;; + esac + dnl Append $CEIL_LIBM to ROUND_LIBM, avoiding gratuitous duplicates. + case " $ROUND_LIBM " in + *" $CEIL_LIBM "*) ;; + *) ROUND_LIBM="$ROUND_LIBM $CEIL_LIBM" ;; + esac + fi + AC_SUBST([ROUND_LIBM]) +]) |