Second try: checks whether right shift extends the sign bit.

Adds caching and reverts back the 'return' to 'exit()' in
AC_TRY_RUN as recommended by the Autoconf documentation.
This commit is contained in:
Vladimir Marangozov 2000-07-12 05:05:06 +00:00
parent 0582df98d3
commit a618028e45
2 changed files with 34 additions and 19 deletions

39
configure vendored
View file

@ -1,6 +1,6 @@
#! /bin/sh
# From configure.in Revision: 1.135
# From configure.in Revision: 1.136
# Guess values for system-dependent variables and create Makefiles.
# Generated automatically using autoconf version 2.13
@ -5604,33 +5604,44 @@ fi
# or fills with zeros (like the Cray J90, according to Tim Peters).
echo $ac_n "checking whether right shift extends the sign bit""... $ac_c" 1>&6
echo "configure:5607: checking whether right shift extends the sign bit" >&5
if eval "test \"`echo '$''{'ac_cv_rshift_extends_sign'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
if test "$cross_compiling" = yes; then
{ echo "configure: error: can not run test program while cross compiling" 1>&2; exit 1; }
else
cat > conftest.$ac_ext <<EOF
#line 5612 "configure"
#line 5616 "configure"
#include "confdefs.h"
int main()
{
return ((-1)>>3 == -1) ? 1 : 0;
exit(((-1)>>3 == -1) ? 0 : 1);
}
EOF
if { (eval echo configure:5621: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext} && (./conftest; exit) 2>/dev/null
if { (eval echo configure:5625: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext} && (./conftest; exit) 2>/dev/null
then
ac_cv_rshift_extends_sign=yes
else
echo "configure: failed program was:" >&5
cat conftest.$ac_ext >&5
rm -fr conftest*
ac_cv_rshift_extends_sign=no
fi
rm -fr conftest*
fi
fi
echo "$ac_t""$ac_cv_rshift_extends_sign" 1>&6
if test "$ac_cv_rshift_extends_sign" = no
then
cat >> confdefs.h <<\EOF
#define SIGNED_RIGHT_SHIFT_ZERO_FILLS 1
EOF
echo "$ac_t""yes" 1>&6
else
echo "configure: failed program was:" >&5
cat conftest.$ac_ext >&5
rm -fr conftest*
echo "$ac_t""no" 1>&6
fi
rm -fr conftest*
fi
@ -5642,12 +5653,12 @@ cat >> confdefs.h <<\EOF
#endif
EOF
echo $ac_n "checking for socklen_t""... $ac_c" 1>&6
echo "configure:5646: checking for socklen_t" >&5
echo "configure:5657: checking for socklen_t" >&5
if eval "test \"`echo '$''{'ac_cv_type_socklen_t'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
cat > conftest.$ac_ext <<EOF
#line 5651 "configure"
#line 5662 "configure"
#include "confdefs.h"
#include <sys/types.h>
#if STDC_HEADERS

View file

@ -1139,15 +1139,19 @@ AC_C_BIGENDIAN
# Check whether right shifting a negative integer extends the sign bit
# or fills with zeros (like the Cray J90, according to Tim Peters).
AC_MSG_CHECKING(whether right shift extends the sign bit)
AC_CACHE_VAL(ac_cv_rshift_extends_sign, [
AC_TRY_RUN([
int main()
{
return ((-1)>>3 == -1) ? 1 : 0;
exit(((-1)>>3 == -1) ? 0 : 1);
}
],
[AC_DEFINE(SIGNED_RIGHT_SHIFT_ZERO_FILLS)
AC_MSG_RESULT(yes)],
[AC_MSG_RESULT(no)])
], ac_cv_rshift_extends_sign=yes, ac_cv_rshift_extends_sign=no)])
AC_MSG_RESULT($ac_cv_rshift_extends_sign)
if test "$ac_cv_rshift_extends_sign" = no
then
AC_DEFINE(SIGNED_RIGHT_SHIFT_ZERO_FILLS)
fi
# THIS MUST BE LAST, IT CAN BREAK OTHER TESTS!
# Add sys/socket.h to confdefs.h