diff options
Diffstat (limited to 'gnulib-m4/frexp.m4')
| -rw-r--r-- | gnulib-m4/frexp.m4 | 112 |
1 files changed, 69 insertions, 43 deletions
diff --git a/gnulib-m4/frexp.m4 b/gnulib-m4/frexp.m4 index 3a450f6..04f4067 100644 --- a/gnulib-m4/frexp.m4 +++ b/gnulib-m4/frexp.m4 @@ -1,5 +1,5 @@ -# frexp.m4 serial 7 -dnl Copyright (C) 2007, 2008, 2009, 2010 Free Software Foundation, Inc. +# frexp.m4 serial 15 +dnl Copyright (C) 2007-2015 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. @@ -7,25 +7,19 @@ dnl with or without modifications, as long as this notice is preserved. AC_DEFUN([gl_FUNC_FREXP], [ AC_REQUIRE([gl_MATH_H_DEFAULTS]) + AC_REQUIRE([gl_CHECK_FREXP_NO_LIBM]) FREXP_LIBM= - AC_CACHE_CHECK([whether frexp() can be used without linking with libm], - [gl_cv_func_frexp_no_libm], - [ - AC_TRY_LINK([#include <math.h> - double x;], - [int e; return frexp (x, &e) > 0;], - [gl_cv_func_frexp_no_libm=yes], - [gl_cv_func_frexp_no_libm=no]) - ]) if test $gl_cv_func_frexp_no_libm = no; then AC_CACHE_CHECK([whether frexp() can be used with libm], [gl_cv_func_frexp_in_libm], [ save_LIBS="$LIBS" LIBS="$LIBS -lm" - AC_TRY_LINK([#include <math.h> - double x;], - [int e; return frexp (x, &e) > 0;], + AC_LINK_IFELSE( + [AC_LANG_PROGRAM( + [[#include <math.h> + double x;]], + [[int e; return frexp (x, &e) > 0;]])], [gl_cv_func_frexp_in_libm=yes], [gl_cv_func_frexp_in_libm=no]) LIBS="$save_LIBS" @@ -50,8 +44,6 @@ AC_DEFUN([gl_FUNC_FREXP], if test $gl_func_frexp = yes; then AC_DEFINE([HAVE_FREXP], [1], [Define if the frexp() function is available and works.]) - else - AC_LIBOBJ([frexp]) fi AC_SUBST([FREXP_LIBM]) ]) @@ -59,15 +51,7 @@ AC_DEFUN([gl_FUNC_FREXP], AC_DEFUN([gl_FUNC_FREXP_NO_LIBM], [ AC_REQUIRE([gl_MATH_H_DEFAULTS]) - AC_CACHE_CHECK([whether frexp() can be used without linking with libm], - [gl_cv_func_frexp_no_libm], - [ - AC_TRY_LINK([#include <math.h> - double x;], - [int e; return frexp (x, &e) > 0;], - [gl_cv_func_frexp_no_libm=yes], - [gl_cv_func_frexp_no_libm=no]) - ]) + AC_REQUIRE([gl_CHECK_FREXP_NO_LIBM]) if test $gl_cv_func_frexp_no_libm = yes; then gl_FUNC_FREXP_WORKS case "$gl_cv_func_frexp_works" in @@ -82,31 +66,71 @@ AC_DEFUN([gl_FUNC_FREXP_NO_LIBM], if test $gl_func_frexp_no_libm = yes; then AC_DEFINE([HAVE_FREXP_IN_LIBC], [1], [Define if the frexp() function is available in libc.]) - else - AC_LIBOBJ([frexp]) fi ]) +dnl Test whether frexp() can be used without linking with libm. +dnl Set gl_cv_func_frexp_no_libm to 'yes' or 'no' accordingly. +AC_DEFUN([gl_CHECK_FREXP_NO_LIBM], +[ + AC_CACHE_CHECK([whether frexp() can be used without linking with libm], + [gl_cv_func_frexp_no_libm], + [ + AC_LINK_IFELSE( + [AC_LANG_PROGRAM( + [[#include <math.h> + double x;]], + [[int e; return frexp (x, &e) > 0;]])], + [gl_cv_func_frexp_no_libm=yes], + [gl_cv_func_frexp_no_libm=no]) + ]) +]) + dnl Test whether frexp() works also on denormalized numbers (this fails e.g. on dnl NetBSD 3.0), on infinite numbers (this fails e.g. on IRIX 6.5 and mingw), -dnl and on negative zero (this fails e.g. on NetBSD 4.99). +dnl and on negative zero (this fails e.g. on NetBSD 4.99 and mingw). AC_DEFUN([gl_FUNC_FREXP_WORKS], [ AC_REQUIRE([AC_PROG_CC]) AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles + AC_CHECK_DECLS_ONCE([alarm]) AC_CACHE_CHECK([whether frexp works], [gl_cv_func_frexp_works], [ - AC_TRY_RUN([ + AC_RUN_IFELSE( + [AC_LANG_SOURCE([[ #include <float.h> #include <math.h> #include <string.h> +#if HAVE_DECL_ALARM +# include <signal.h> +# include <unistd.h> +#endif +/* HP cc on HP-UX 10.20 has a bug with the constant expression -0.0. + ICC 10.0 has a bug when optimizing the expression -zero. + The expression -DBL_MIN * DBL_MIN does not work when cross-compiling + to PowerPC on Mac OS X 10.5. */ +#if defined __hpux || defined __sgi || defined __ICC +static double +compute_minus_zero (void) +{ + return -DBL_MIN * DBL_MIN; +} +# define minus_zero compute_minus_zero () +#else +double minus_zero = -0.0; +#endif int main() { + int result = 0; int i; volatile double x; -/* HP cc on HP-UX 10.20 has a bug with the constant expression -0.0. - So we use -zero instead. */ double zero = 0.0; +#if HAVE_DECL_ALARM + /* NeXTstep 3.3 frexp() runs into an endless loop when called on an infinite + number. Let the test fail in this case. */ + signal (SIGALRM, SIG_DFL); + alarm (5); +#endif /* Test on denormalized numbers. */ for (i = 1, x = 1.0; i >= DBL_MIN_EXP; i--, x *= 0.5) ; @@ -117,30 +141,32 @@ int main() /* On machines with IEEE754 arithmetic: x = 1.11254e-308, exp = -1022. On NetBSD: y = 0.75. Correct: y = 0.5. */ if (y != 0.5) - return 1; + result |= 1; } /* Test on infinite numbers. */ - x = 1.0 / 0.0; + x = 1.0 / zero; { int exp; double y = frexp (x, &exp); if (y != x) - return 1; + result |= 2; } /* Test on negative zero. */ - x = -zero; + x = minus_zero; { int exp; double y = frexp (x, &exp); if (memcmp (&y, &x, sizeof x)) - return 1; + result |= 4; } - return 0; -}], [gl_cv_func_frexp_works=yes], [gl_cv_func_frexp_works=no], - [case "$host_os" in - netbsd* | irix* | mingw*) gl_cv_func_frexp_works="guessing no";; - *) gl_cv_func_frexp_works="guessing yes";; - esac - ]) + return result; +}]])], + [gl_cv_func_frexp_works=yes], + [gl_cv_func_frexp_works=no], + [case "$host_os" in + netbsd* | irix* | mingw*) gl_cv_func_frexp_works="guessing no";; + *) gl_cv_func_frexp_works="guessing yes";; + esac + ]) ]) ]) |