-], result=yes)
- if test -z "$result"; then
- dnl Define it ourselves. Here we assume that the type 'size_t' is not wider
- dnl than the type 'unsigned long'.
- dnl The _AC_COMPUTE_INT macro works up to LONG_MAX, since it uses 'expr',
- dnl which is guaranteed to work from LONG_MIN to LONG_MAX.
- _AC_COMPUTE_INT([~(size_t)0 / 10], res_hi,
- [#include <stddef.h>], result=?)
- _AC_COMPUTE_INT([~(size_t)0 % 10], res_lo,
- [#include <stddef.h>], result=?)
- _AC_COMPUTE_INT([sizeof (size_t) <= sizeof (unsigned int)], fits_in_uint,
- [#include <stddef.h>], result=?)
- if test "$fits_in_uint" = 1; then
- dnl Even though SIZE_MAX fits in an unsigned int, it must be of type
- dnl 'unsigned long' if the type 'size_t' is the same as 'unsigned long'.
- AC_TRY_COMPILE([#include <stddef.h>
- extern size_t foo;
- extern unsigned long foo;
- ], [], fits_in_uint=0)
- fi
- if test -z "$result"; then
- if test "$fits_in_uint" = 1; then
- result="$res_hi$res_lo"U
+], [gl_cv_size_max=yes])
+ if test -z "$gl_cv_size_max"; then
+ dnl Define it ourselves. Here we assume that the type 'size_t' is not wider
+ dnl than the type 'unsigned long'. Try hard to find a definition that can
+ dnl be used in a preprocessor #if, i.e. doesn't contain a cast.
+ AC_COMPUTE_INT([size_t_bits_minus_1], [sizeof (size_t) * CHAR_BIT - 1],
+ [#include <stddef.h>
+#include <limits.h>], [size_t_bits_minus_1=])
+ AC_COMPUTE_INT([fits_in_uint], [sizeof (size_t) <= sizeof (unsigned int)],
+ [#include <stddef.h>], [fits_in_uint=])
+ if test -n "$size_t_bits_minus_1" && test -n "$fits_in_uint"; then
+ if test $fits_in_uint = 1; then
+ dnl Even though SIZE_MAX fits in an unsigned int, it must be of type
+ dnl 'unsigned long' if the type 'size_t' is the same as 'unsigned long'.
+ AC_TRY_COMPILE([#include <stddef.h>
+ extern size_t foo;
+ extern unsigned long foo;
+ ], [], [fits_in_uint=0])
+ fi
+ dnl We cannot use 'expr' to simplify this expression, because 'expr'
+ dnl works only with 'long' integers in the host environment, while we
+ dnl might be cross-compiling from a 32-bit platform to a 64-bit platform.
+ if test $fits_in_uint = 1; then
+ gl_cv_size_max="(((1U << $size_t_bits_minus_1) - 1) * 2 + 1)"
+ else
+ gl_cv_size_max="(((1UL << $size_t_bits_minus_1) - 1) * 2 + 1)"
+ fi