Bug 405992: Implement native atomic operations for Linux/ARM. The patch is

contributed by Ilpo Ruotsalainen <ilpo.ruotsalainen@movial.fi>.  r=wtc.
Modified files: configure.in configure _linux.h

3 files changed, 167 insertions, 101 deletions

diff --git a/configure b/configure
index d22d2233..c33f6def 100755
--- a/configure
+++ b/configure
@@ -42,6 +42,9 @@ ac_help="$ac_help
 ac_help="$ac_help
   --enable-cplus          Enable some c++ api routines"
 ac_help="$ac_help
+  --with-arm-kuser        Use kuser helpers (Linux/ARM only)
+                          (Requires kernel 2.6.13 or later)"
+ac_help="$ac_help
   --with-macos-sdk=dir    Location of platform SDK to use (Mac OS X only)"
 ac_help="$ac_help
   --enable-macos-target=VER
@@ -625,7 +628,7 @@ else { echo "configure: error: can not run $ac_config_sub" 1>&2; exit 1; }
 fi
 
 echo $ac_n "checking host system type""... $ac_c" 1>&6
-echo "configure:629: checking host system type" >&5
+echo "configure:632: checking host system type" >&5
 
 host_alias=$host
 case "$host_alias" in
@@ -646,7 +649,7 @@ host_os=`echo $host | sed 's/^\([^-]*\)-\([^-]*\)-\(.*\)$/\3/'`
 echo "$ac_t""$host" 1>&6
 
 echo $ac_n "checking target system type""... $ac_c" 1>&6
-echo "configure:650: checking target system type" >&5
+echo "configure:653: checking target system type" >&5
 
 target_alias=$target
 case "$target_alias" in
@@ -664,7 +667,7 @@ target_os=`echo $target | sed 's/^\([^-]*\)-\([^-]*\)-\(.*\)$/\3/'`
 echo "$ac_t""$target" 1>&6
 
 echo $ac_n "checking build system type""... $ac_c" 1>&6
-echo "configure:668: checking build system type" >&5
+echo "configure:671: checking build system type" >&5
 
 build_alias=$build
 case "$build_alias" in
@@ -735,7 +738,7 @@ do
 # Extract the first word of "$ac_prog", so it can be a program name with args.
 set dummy $ac_prog; ac_word=$2
 echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:739: checking for $ac_word" >&5
+echo "configure:742: checking for $ac_word" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_CC'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -940,6 +943,18 @@ if test "${enable_cplus+set}" = set; then
 fi
  
 
+# Check whether --with-arm-kuser or --without-arm-kuser was given.
+if test "${with_arm_kuser+set}" = set; then
+  withval="$with_arm_kuser"
+   if test "$withval" = "yes"; then
+	    cat >> confdefs.h <<\EOF
+#define _PR_ARM_KUSER 1
+EOF
+
+      fi 
+fi
+
+
 # Check whether --with-macos-sdk or --without-macos-sdk was given.
 if test "${with_macos_sdk+set}" = set; then
   withval="$with_macos_sdk"
@@ -1051,7 +1066,7 @@ if test -z "$SKIP_PATH_CHECKS"; then
     # Extract the first word of "$WHOAMI whoami", so it can be a program name with args.
 set dummy $WHOAMI whoami; ac_word=$2
 echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:1055: checking for $ac_word" >&5
+echo "configure:1070: checking for $ac_word" >&5
 if eval "test \"`echo '$''{'ac_cv_path_WHOAMI'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -1122,13 +1137,13 @@ if test "$target" != "$host"; then
     _SAVE_LDFLAGS="$LDFLAGS"
 
     echo $ac_n "checking for $host compiler""... $ac_c" 1>&6
-echo "configure:1126: checking for $host compiler" >&5
+echo "configure:1141: checking for $host compiler" >&5
     for ac_prog in $HOST_CC gcc cc /usr/ucb/cc
 do
 # Extract the first word of "$ac_prog", so it can be a program name with args.
 set dummy $ac_prog; ac_word=$2
 echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:1132: checking for $ac_word" >&5
+echo "configure:1147: checking for $ac_word" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_HOST_CC'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -1174,16 +1189,16 @@ test -n "$HOST_CC" || HOST_CC=""""
     LDFLAGS="$HOST_LDFLAGS"
 
     echo $ac_n "checking whether the $host compiler ($HOST_CC $HOST_CFLAGS $HOST_LDFLAGS) works""... $ac_c" 1>&6
-echo "configure:1178: checking whether the $host compiler ($HOST_CC $HOST_CFLAGS $HOST_LDFLAGS) works" >&5
+echo "configure:1193: checking whether the $host compiler ($HOST_CC $HOST_CFLAGS $HOST_LDFLAGS) works" >&5
     cat > conftest.$ac_ext <<EOF
-#line 1180 "configure"
+#line 1195 "configure"
 #include "confdefs.h"
 
 int main() {
 return(0);
 ; return 0; }
 EOF
-if { (eval echo configure:1187: \"$ac_compile\") 1>&5; (eval $ac_compile) 2>&5; }; then
+if { (eval echo configure:1202: \"$ac_compile\") 1>&5; (eval $ac_compile) 2>&5; }; then
   rm -rf conftest*
   ac_cv_prog_host_cc_works=1 echo "$ac_t""yes" 1>&6
 else
@@ -1212,7 +1227,7 @@ do
 # Extract the first word of "$ac_prog", so it can be a program name with args.
 set dummy $ac_prog; ac_word=$2
 echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:1216: checking for $ac_word" >&5
+echo "configure:1231: checking for $ac_word" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_CC'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -1246,7 +1261,7 @@ test -n "$CC" || CC="echo"
     # Extract the first word of "gcc", so it can be a program name with args.
 set dummy gcc; ac_word=$2
 echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:1250: checking for $ac_word" >&5
+echo "configure:1265: checking for $ac_word" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_CC'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -1276,7 +1291,7 @@ if test -z "$CC"; then
   # Extract the first word of "cc", so it can be a program name with args.
 set dummy cc; ac_word=$2
 echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:1280: checking for $ac_word" >&5
+echo "configure:1295: checking for $ac_word" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_CC'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -1327,7 +1342,7 @@ fi
       # Extract the first word of "cl", so it can be a program name with args.
 set dummy cl; ac_word=$2
 echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:1331: checking for $ac_word" >&5
+echo "configure:1346: checking for $ac_word" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_CC'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -1359,7 +1374,7 @@ fi
 fi
 
 echo $ac_n "checking whether the C compiler ($CC $CFLAGS $LDFLAGS) works""... $ac_c" 1>&6
-echo "configure:1363: checking whether the C compiler ($CC $CFLAGS $LDFLAGS) works" >&5
+echo "configure:1378: checking whether the C compiler ($CC $CFLAGS $LDFLAGS) works" >&5
 
 ac_ext=c
 # CFLAGS is not in ac_cpp because -g, -O, etc. are not valid cpp options.
@@ -1370,12 +1385,12 @@ cross_compiling=$ac_cv_prog_cc_cross
 
 cat > conftest.$ac_ext << EOF
 
-#line 1374 "configure"
+#line 1389 "configure"
 #include "confdefs.h"
 
 main(){return(0);}
 EOF
-if { (eval echo configure:1379: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
+if { (eval echo configure:1394: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
   ac_cv_prog_cc_works=yes
   # If we can't run a trivial program, we are probably using a cross compiler.
   if (./conftest; exit) 2>/dev/null; then
@@ -1401,12 +1416,12 @@ if test $ac_cv_prog_cc_works = no; then
   { echo "configure: error: installation or configuration problem: C compiler cannot create executables." 1>&2; exit 1; }
 fi
 echo $ac_n "checking whether the C compiler ($CC $CFLAGS $LDFLAGS) is a cross-compiler""... $ac_c" 1>&6
-echo "configure:1405: checking whether the C compiler ($CC $CFLAGS $LDFLAGS) is a cross-compiler" >&5
+echo "configure:1420: checking whether the C compiler ($CC $CFLAGS $LDFLAGS) is a cross-compiler" >&5
 echo "$ac_t""$ac_cv_prog_cc_cross" 1>&6
 cross_compiling=$ac_cv_prog_cc_cross
 
 echo $ac_n "checking whether we are using GNU C""... $ac_c" 1>&6
-echo "configure:1410: checking whether we are using GNU C" >&5
+echo "configure:1425: checking whether we are using GNU C" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_gcc'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -1415,7 +1430,7 @@ else
   yes;
 #endif
 EOF
-if { ac_try='${CC-cc} -E conftest.c'; { (eval echo configure:1419: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; } | egrep yes >/dev/null 2>&1; then
+if { ac_try='${CC-cc} -E conftest.c'; { (eval echo configure:1434: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; } | egrep yes >/dev/null 2>&1; then
   ac_cv_prog_gcc=yes
 else
   ac_cv_prog_gcc=no
@@ -1434,7 +1449,7 @@ ac_test_CFLAGS="${CFLAGS+set}"
 ac_save_CFLAGS="$CFLAGS"
 CFLAGS=
 echo $ac_n "checking whether ${CC-cc} accepts -g""... $ac_c" 1>&6
-echo "configure:1438: checking whether ${CC-cc} accepts -g" >&5
+echo "configure:1453: checking whether ${CC-cc} accepts -g" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_cc_g'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -1471,7 +1486,7 @@ do
 # Extract the first word of "$ac_prog", so it can be a program name with args.
 set dummy $ac_prog; ac_word=$2
 echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:1475: checking for $ac_word" >&5
+echo "configure:1490: checking for $ac_word" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_CXX'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -1507,7 +1522,7 @@ do
 # Extract the first word of "$ac_prog", so it can be a program name with args.
 set dummy $ac_prog; ac_word=$2
 echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:1511: checking for $ac_word" >&5
+echo "configure:1526: checking for $ac_word" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_CXX'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -1539,7 +1554,7 @@ test -n "$CXX" || CXX="gcc"
 
 
 echo $ac_n "checking whether the C++ compiler ($CXX $CXXFLAGS $LDFLAGS) works""... $ac_c" 1>&6
-echo "configure:1543: checking whether the C++ compiler ($CXX $CXXFLAGS $LDFLAGS) works" >&5
+echo "configure:1558: checking whether the C++ compiler ($CXX $CXXFLAGS $LDFLAGS) works" >&5
 
 ac_ext=C
 # CXXFLAGS is not in ac_cpp because -g, -O, etc. are not valid cpp options.
@@ -1550,12 +1565,12 @@ cross_compiling=$ac_cv_prog_cxx_cross
 
 cat > conftest.$ac_ext << EOF
 
-#line 1554 "configure"
+#line 1569 "configure"
 #include "confdefs.h"
 
 int main(){return(0);}
 EOF
-if { (eval echo configure:1559: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
+if { (eval echo configure:1574: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
   ac_cv_prog_cxx_works=yes
   # If we can't run a trivial program, we are probably using a cross compiler.
   if (./conftest; exit) 2>/dev/null; then
@@ -1581,12 +1596,12 @@ if test $ac_cv_prog_cxx_works = no; then
   { echo "configure: error: installation or configuration problem: C++ compiler cannot create executables." 1>&2; exit 1; }
 fi
 echo $ac_n "checking whether the C++ compiler ($CXX $CXXFLAGS $LDFLAGS) is a cross-compiler""... $ac_c" 1>&6
-echo "configure:1585: checking whether the C++ compiler ($CXX $CXXFLAGS $LDFLAGS) is a cross-compiler" >&5
+echo "configure:1600: checking whether the C++ compiler ($CXX $CXXFLAGS $LDFLAGS) is a cross-compiler" >&5
 echo "$ac_t""$ac_cv_prog_cxx_cross" 1>&6
 cross_compiling=$ac_cv_prog_cxx_cross
 
 echo $ac_n "checking whether we are using GNU C++""... $ac_c" 1>&6
-echo "configure:1590: checking whether we are using GNU C++" >&5
+echo "configure:1605: checking whether we are using GNU C++" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_gxx'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -1595,7 +1610,7 @@ else
   yes;
 #endif
 EOF
-if { ac_try='${CXX-g++} -E conftest.C'; { (eval echo configure:1599: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; } | egrep yes >/dev/null 2>&1; then
+if { ac_try='${CXX-g++} -E conftest.C'; { (eval echo configure:1614: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; } | egrep yes >/dev/null 2>&1; then
   ac_cv_prog_gxx=yes
 else
   ac_cv_prog_gxx=no
@@ -1614,7 +1629,7 @@ ac_test_CXXFLAGS="${CXXFLAGS+set}"
 ac_save_CXXFLAGS="$CXXFLAGS"
 CXXFLAGS=
 echo $ac_n "checking whether ${CXX-g++} accepts -g""... $ac_c" 1>&6
-echo "configure:1618: checking whether ${CXX-g++} accepts -g" >&5
+echo "configure:1633: checking whether ${CXX-g++} accepts -g" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_cxx_g'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -1659,7 +1674,7 @@ do
 # Extract the first word of "$ac_prog", so it can be a program name with args.
 set dummy $ac_prog; ac_word=$2
 echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:1663: checking for $ac_word" >&5
+echo "configure:1678: checking for $ac_word" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_RANLIB'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -1694,7 +1709,7 @@ do
 # Extract the first word of "$ac_prog", so it can be a program name with args.
 set dummy $ac_prog; ac_word=$2
 echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:1698: checking for $ac_word" >&5
+echo "configure:1713: checking for $ac_word" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_AR'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -1729,7 +1744,7 @@ do
 # Extract the first word of "$ac_prog", so it can be a program name with args.
 set dummy $ac_prog; ac_word=$2
 echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:1733: checking for $ac_word" >&5
+echo "configure:1748: checking for $ac_word" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_AS'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -1764,7 +1779,7 @@ do
 # Extract the first word of "$ac_prog", so it can be a program name with args.
 set dummy $ac_prog; ac_word=$2
 echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:1768: checking for $ac_word" >&5
+echo "configure:1783: checking for $ac_word" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_LD'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -1799,7 +1814,7 @@ do
 # Extract the first word of "$ac_prog", so it can be a program name with args.
 set dummy $ac_prog; ac_word=$2
 echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:1803: checking for $ac_word" >&5
+echo "configure:1818: checking for $ac_word" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_STRIP'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -1834,7 +1849,7 @@ do
 # Extract the first word of "$ac_prog", so it can be a program name with args.
 set dummy $ac_prog; ac_word=$2
 echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:1838: checking for $ac_word" >&5
+echo "configure:1853: checking for $ac_word" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_WINDRES'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -1869,7 +1884,7 @@ else
     # Extract the first word of "gcc", so it can be a program name with args.
 set dummy gcc; ac_word=$2
 echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:1873: checking for $ac_word" >&5
+echo "configure:1888: checking for $ac_word" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_CC'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -1899,7 +1914,7 @@ if test -z "$CC"; then
   # Extract the first word of "cc", so it can be a program name with args.
 set dummy cc; ac_word=$2
 echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:1903: checking for $ac_word" >&5
+echo "configure:1918: checking for $ac_word" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_CC'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -1950,7 +1965,7 @@ fi
       # Extract the first word of "cl", so it can be a program name with args.
 set dummy cl; ac_word=$2
 echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:1954: checking for $ac_word" >&5
+echo "configure:1969: checking for $ac_word" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_CC'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -1982,7 +1997,7 @@ fi
 fi
 
 echo $ac_n "checking whether the C compiler ($CC $CFLAGS $LDFLAGS) works""... $ac_c" 1>&6
-echo "configure:1986: checking whether the C compiler ($CC $CFLAGS $LDFLAGS) works" >&5
+echo "configure:2001: checking whether the C compiler ($CC $CFLAGS $LDFLAGS) works" >&5
 
 ac_ext=c
 # CFLAGS is not in ac_cpp because -g, -O, etc. are not valid cpp options.
@@ -1993,12 +2008,12 @@ cross_compiling=$ac_cv_prog_cc_cross
 
 cat > conftest.$ac_ext << EOF
 
-#line 1997 "configure"
+#line 2012 "configure"
 #include "confdefs.h"
 
 main(){return(0);}
 EOF
-if { (eval echo configure:2002: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
+if { (eval echo configure:2017: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
   ac_cv_prog_cc_works=yes
   # If we can't run a trivial program, we are probably using a cross compiler.
   if (./conftest; exit) 2>/dev/null; then
@@ -2024,12 +2039,12 @@ if test $ac_cv_prog_cc_works = no; then
   { echo "configure: error: installation or configuration problem: C compiler cannot create executables." 1>&2; exit 1; }
 fi
 echo $ac_n "checking whether the C compiler ($CC $CFLAGS $LDFLAGS) is a cross-compiler""... $ac_c" 1>&6
-echo "configure:2028: checking whether the C compiler ($CC $CFLAGS $LDFLAGS) is a cross-compiler" >&5
+echo "configure:2043: checking whether the C compiler ($CC $CFLAGS $LDFLAGS) is a cross-compiler" >&5
 echo "$ac_t""$ac_cv_prog_cc_cross" 1>&6
 cross_compiling=$ac_cv_prog_cc_cross
 
 echo $ac_n "checking whether we are using GNU C""... $ac_c" 1>&6
-echo "configure:2033: checking whether we are using GNU C" >&5
+echo "configure:2048: checking whether we are using GNU C" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_gcc'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -2038,7 +2053,7 @@ else
   yes;
 #endif
 EOF
-if { ac_try='${CC-cc} -E conftest.c'; { (eval echo configure:2042: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; } | egrep yes >/dev/null 2>&1; then
+if { ac_try='${CC-cc} -E conftest.c'; { (eval echo configure:2057: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; } | egrep yes >/dev/null 2>&1; then
   ac_cv_prog_gcc=yes
 else
   ac_cv_prog_gcc=no
@@ -2057,7 +2072,7 @@ ac_test_CFLAGS="${CFLAGS+set}"
 ac_save_CFLAGS="$CFLAGS"
 CFLAGS=
 echo $ac_n "checking whether ${CC-cc} accepts -g""... $ac_c" 1>&6
-echo "configure:2061: checking whether ${CC-cc} accepts -g" >&5
+echo "configure:2076: checking whether ${CC-cc} accepts -g" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_cc_g'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -2097,7 +2112,7 @@ do
 # Extract the first word of "$ac_prog", so it can be a program name with args.
 set dummy $ac_prog; ac_word=$2
 echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:2101: checking for $ac_word" >&5
+echo "configure:2116: checking for $ac_word" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_CXX'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -2129,7 +2144,7 @@ test -n "$CXX" || CXX="gcc"
 
 
 echo $ac_n "checking whether the C++ compiler ($CXX $CXXFLAGS $LDFLAGS) works""... $ac_c" 1>&6
-echo "configure:2133: checking whether the C++ compiler ($CXX $CXXFLAGS $LDFLAGS) works" >&5
+echo "configure:2148: checking whether the C++ compiler ($CXX $CXXFLAGS $LDFLAGS) works" >&5
 
 ac_ext=C
 # CXXFLAGS is not in ac_cpp because -g, -O, etc. are not valid cpp options.
@@ -2140,12 +2155,12 @@ cross_compiling=$ac_cv_prog_cxx_cross
 
 cat > conftest.$ac_ext << EOF
 
-#line 2144 "configure"
+#line 2159 "configure"
 #include "confdefs.h"
 
 int main(){return(0);}
 EOF
-if { (eval echo configure:2149: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
+if { (eval echo configure:2164: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
   ac_cv_prog_cxx_works=yes
   # If we can't run a trivial program, we are probably using a cross compiler.
   if (./conftest; exit) 2>/dev/null; then
@@ -2171,12 +2186,12 @@ if test $ac_cv_prog_cxx_works = no; then
   { echo "configure: error: installation or configuration problem: C++ compiler cannot create executables." 1>&2; exit 1; }
 fi
 echo $ac_n "checking whether the C++ compiler ($CXX $CXXFLAGS $LDFLAGS) is a cross-compiler""... $ac_c" 1>&6
-echo "configure:2175: checking whether the C++ compiler ($CXX $CXXFLAGS $LDFLAGS) is a cross-compiler" >&5
+echo "configure:2190: checking whether the C++ compiler ($CXX $CXXFLAGS $LDFLAGS) is a cross-compiler" >&5
 echo "$ac_t""$ac_cv_prog_cxx_cross" 1>&6
 cross_compiling=$ac_cv_prog_cxx_cross
 
 echo $ac_n "checking whether we are using GNU C++""... $ac_c" 1>&6
-echo "configure:2180: checking whether we are using GNU C++" >&5
+echo "configure:2195: checking whether we are using GNU C++" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_gxx'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -2185,7 +2200,7 @@ else
   yes;
 #endif
 EOF
-if { ac_try='${CXX-g++} -E conftest.C'; { (eval echo configure:2189: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; } | egrep yes >/dev/null 2>&1; then
+if { ac_try='${CXX-g++} -E conftest.C'; { (eval echo configure:2204: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; } | egrep yes >/dev/null 2>&1; then
   ac_cv_prog_gxx=yes
 else
   ac_cv_prog_gxx=no
@@ -2204,7 +2219,7 @@ ac_test_CXXFLAGS="${CXXFLAGS+set}"
 ac_save_CXXFLAGS="$CXXFLAGS"
 CXXFLAGS=
 echo $ac_n "checking whether ${CXX-g++} accepts -g""... $ac_c" 1>&6
-echo "configure:2208: checking whether ${CXX-g++} accepts -g" >&5
+echo "configure:2223: checking whether ${CXX-g++} accepts -g" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_cxx_g'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -2238,7 +2253,7 @@ fi
         fi
     fi
     echo $ac_n "checking how to run the C preprocessor""... $ac_c" 1>&6
-echo "configure:2242: checking how to run the C preprocessor" >&5
+echo "configure:2257: checking how to run the C preprocessor" >&5
 # On Suns, sometimes $CPP names a directory.
 if test -n "$CPP" && test -d "$CPP"; then
   CPP=
@@ -2253,13 +2268,13 @@ else
   # On the NeXT, cc -E runs the code through the compiler's parser,
   # not just through cpp.
   cat > conftest.$ac_ext <<EOF
-#line 2257 "configure"
+#line 2272 "configure"
 #include "confdefs.h"
 #include <assert.h>
 Syntax Error
 EOF
 ac_try="$ac_cpp conftest.$ac_ext >/dev/null 2>conftest.out"
-{ (eval echo configure:2263: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
+{ (eval echo configure:2278: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
 ac_err=`grep -v '^ *+' conftest.out | grep -v "^conftest.${ac_ext}\$"`
 if test -z "$ac_err"; then
   :
@@ -2270,13 +2285,13 @@ else
   rm -rf conftest*
   CPP="${CC-cc} -E -traditional-cpp"
   cat > conftest.$ac_ext <<EOF
-#line 2274 "configure"
+#line 2289 "configure"
 #include "confdefs.h"
 #include <assert.h>
 Syntax Error
 EOF
 ac_try="$ac_cpp conftest.$ac_ext >/dev/null 2>conftest.out"
-{ (eval echo configure:2280: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
+{ (eval echo configure:2295: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
 ac_err=`grep -v '^ *+' conftest.out | grep -v "^conftest.${ac_ext}\$"`
 if test -z "$ac_err"; then
   :
@@ -2287,13 +2302,13 @@ else
   rm -rf conftest*
   CPP="${CC-cc} -nologo -E"
   cat > conftest.$ac_ext <<EOF
-#line 2291 "configure"
+#line 2306 "configure"
 #include "confdefs.h"
 #include <assert.h>
 Syntax Error
 EOF
 ac_try="$ac_cpp conftest.$ac_ext >/dev/null 2>conftest.out"
-{ (eval echo configure:2297: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
+{ (eval echo configure:2312: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
 ac_err=`grep -v '^ *+' conftest.out | grep -v "^conftest.${ac_ext}\$"`
 if test -z "$ac_err"; then
   :
@@ -2320,7 +2335,7 @@ echo "$ac_t""$CPP" 1>&6
     # Extract the first word of "ranlib", so it can be a program name with args.
 set dummy ranlib; ac_word=$2
 echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:2324: checking for $ac_word" >&5
+echo "configure:2339: checking for $ac_word" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_RANLIB'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -2352,7 +2367,7 @@ do
 # Extract the first word of "$ac_prog", so it can be a program name with args.
 set dummy $ac_prog; ac_word=$2
 echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:2356: checking for $ac_word" >&5
+echo "configure:2371: checking for $ac_word" >&5
 if eval "test \"`echo '$''{'ac_cv_path_AS'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -2393,7 +2408,7 @@ do
 # Extract the first word of "$ac_prog", so it can be a program name with args.
 set dummy $ac_prog; ac_word=$2
 echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:2397: checking for $ac_word" >&5
+echo "configure:2412: checking for $ac_word" >&5
 if eval "test \"`echo '$''{'ac_cv_path_AR'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -2434,7 +2449,7 @@ do
 # Extract the first word of "$ac_prog", so it can be a program name with args.
 set dummy $ac_prog; ac_word=$2
 echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:2438: checking for $ac_word" >&5
+echo "configure:2453: checking for $ac_word" >&5
 if eval "test \"`echo '$''{'ac_cv_path_LD'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -2475,7 +2490,7 @@ do
 # Extract the first word of "$ac_prog", so it can be a program name with args.
 set dummy $ac_prog; ac_word=$2
 echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:2479: checking for $ac_word" >&5
+echo "configure:2494: checking for $ac_word" >&5
 if eval "test \"`echo '$''{'ac_cv_path_STRIP'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -2516,7 +2531,7 @@ do
 # Extract the first word of "$ac_prog", so it can be a program name with args.
 set dummy $ac_prog; ac_word=$2
 echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:2520: checking for $ac_word" >&5
+echo "configure:2535: checking for $ac_word" >&5
 if eval "test \"`echo '$''{'ac_cv_path_WINDRES'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -2584,7 +2599,7 @@ else
 fi
 
 echo $ac_n "checking for gcc -pipe support""... $ac_c" 1>&6
-echo "configure:2588: checking for gcc -pipe support" >&5
+echo "configure:2603: checking for gcc -pipe support" >&5
 if test -n "$GNU_CC" && test -n "$GNU_CXX" && test -n "$GNU_AS"; then
     echo '#include <stdio.h>' > dummy-hello.c
     echo 'int main() { printf("Hello World\n"); return 0; }' >> dummy-hello.c
@@ -2599,14 +2614,14 @@ if test -n "$GNU_CC" && test -n "$GNU_CXX" && test -n "$GNU_AS"; then
         _SAVE_CFLAGS=$CFLAGS
         CFLAGS="$CFLAGS -pipe"
         cat > conftest.$ac_ext <<EOF
-#line 2603 "configure"
+#line 2618 "configure"
 #include "confdefs.h"
  #include <stdio.h> 
 int main() {
 printf("Hello World\n");
 ; return 0; }
 EOF
-if { (eval echo configure:2610: \"$ac_compile\") 1>&5; (eval $ac_compile) 2>&5; }; then
+if { (eval echo configure:2625: \"$ac_compile\") 1>&5; (eval $ac_compile) 2>&5; }; then
   rm -rf conftest*
   _res_gcc_pipe="yes"
 else
@@ -2633,7 +2648,7 @@ fi
 
 if test "$GNU_CC"; then
     echo $ac_n "checking for visibility(hidden) attribute""... $ac_c" 1>&6
-echo "configure:2637: checking for visibility(hidden) attribute" >&5
+echo "configure:2652: checking for visibility(hidden) attribute" >&5
 if eval "test \"`echo '$''{'ac_cv_visibility_hidden'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -2657,7 +2672,7 @@ echo "$ac_t""$ac_cv_visibility_hidden" 1>&6
 EOF
 
         echo $ac_n "checking for visibility pragma support""... $ac_c" 1>&6
-echo "configure:2661: checking for visibility pragma support" >&5
+echo "configure:2676: checking for visibility pragma support" >&5
 if eval "test \"`echo '$''{'ac_cv_visibility_pragma'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -2710,7 +2725,7 @@ do
 # Extract the first word of "$ac_prog", so it can be a program name with args.
 set dummy $ac_prog; ac_word=$2
 echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:2714: checking for $ac_word" >&5
+echo "configure:2729: checking for $ac_word" >&5
 if eval "test \"`echo '$''{'ac_cv_path_PERL'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -2967,17 +2982,17 @@ EOF
     DSO_LDOPTS='-brtl -bnortllib -bM:SRE -bnoentry -bexpall -blibpath:/usr/lib:/lib'
     ac_safe=`echo "sys/atomic_op.h" | sed 'y%./+-%__p_%'`
 echo $ac_n "checking for sys/atomic_op.h""... $ac_c" 1>&6
-echo "configure:2971: checking for sys/atomic_op.h" >&5
+echo "configure:2986: checking for sys/atomic_op.h" >&5
 if eval "test \"`echo '$''{'ac_cv_header_$ac_safe'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
   cat > conftest.$ac_ext <<EOF
-#line 2976 "configure"
+#line 2991 "configure"
 #include "confdefs.h"
 #include <sys/atomic_op.h>
 EOF
 ac_try="$ac_cpp conftest.$ac_ext >/dev/null 2>conftest.out"
-{ (eval echo configure:2981: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
+{ (eval echo configure:2996: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
 ac_err=`grep -v '^ *+' conftest.out | grep -v "^conftest.${ac_ext}\$"`
 if test -z "$ac_err"; then
   rm -rf conftest*
@@ -3134,7 +3149,7 @@ EOF
         _DEBUG_FLAGS='-gdwarf-2 -O0'
         MKSHLIB='$(CCC) $(DSO_LDOPTS) -o $@'
         echo $ac_n "checking for gethostbyaddr in -lbind""... $ac_c" 1>&6
-echo "configure:3138: checking for gethostbyaddr in -lbind" >&5
+echo "configure:3153: checking for gethostbyaddr in -lbind" >&5
 ac_lib_var=`echo bind'_'gethostbyaddr | sed 'y%./+-%__p_%'`
 if eval "test \"`echo '$''{'ac_cv_lib_$ac_lib_var'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
@@ -3142,7 +3157,7 @@ else
   ac_save_LIBS="$LIBS"
 LIBS="-lbind  $LIBS"
 cat > conftest.$ac_ext <<EOF
-#line 3146 "configure"
+#line 3161 "configure"
 #include "confdefs.h"
 /* Override any gcc2 internal prototype to avoid an error.  */
 /* We use char because int might match the return type of a gcc2
@@ -3153,7 +3168,7 @@ int main() {
 gethostbyaddr()
 ; return 0; }
 EOF
-if { (eval echo configure:3157: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
+if { (eval echo configure:3172: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
   rm -rf conftest*
   eval "ac_cv_lib_$ac_lib_var=yes"
 else
@@ -4488,17 +4503,17 @@ EOF
         _OPTIMIZE_FLAGS="$_OPTIMIZE_FLAGS -Olimit 4000"
         ac_safe=`echo "machine/builtins.h" | sed 'y%./+-%__p_%'`
 echo $ac_n "checking for machine/builtins.h""... $ac_c" 1>&6
-echo "configure:4492: checking for machine/builtins.h" >&5
+echo "configure:4507: checking for machine/builtins.h" >&5
 if eval "test \"`echo '$''{'ac_cv_header_$ac_safe'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
   cat > conftest.$ac_ext <<EOF
-#line 4497 "configure"
+#line 4512 "configure"
 #include "confdefs.h"
 #include <machine/builtins.h>
 EOF
 ac_try="$ac_cpp conftest.$ac_ext >/dev/null 2>conftest.out"
-{ (eval echo configure:4502: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
+{ (eval echo configure:4517: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
 ac_err=`grep -v '^ *+' conftest.out | grep -v "^conftest.${ac_ext}\$"`
 if test -z "$ac_err"; then
   rm -rf conftest*
@@ -5068,7 +5083,7 @@ case $target in
     ;;
 *)
     echo $ac_n "checking for dlopen in -ldl""... $ac_c" 1>&6
-echo "configure:5072: checking for dlopen in -ldl" >&5
+echo "configure:5087: checking for dlopen in -ldl" >&5
 ac_lib_var=`echo dl'_'dlopen | sed 'y%./+-%__p_%'`
 if eval "test \"`echo '$''{'ac_cv_lib_$ac_lib_var'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
@@ -5076,7 +5091,7 @@ else
   ac_save_LIBS="$LIBS"
 LIBS="-ldl  $LIBS"
 cat > conftest.$ac_ext <<EOF
-#line 5080 "configure"
+#line 5095 "configure"
 #include "confdefs.h"
 /* Override any gcc2 internal prototype to avoid an error.  */
 /* We use char because int might match the return type of a gcc2
@@ -5087,7 +5102,7 @@ int main() {
 dlopen()
 ; return 0; }
 EOF
-if { (eval echo configure:5091: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
+if { (eval echo configure:5106: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
   rm -rf conftest*
   eval "ac_cv_lib_$ac_lib_var=yes"
 else
@@ -5104,17 +5119,17 @@ if eval "test \"`echo '$ac_cv_lib_'$ac_lib_var`\" = yes"; then
   echo "$ac_t""yes" 1>&6
   ac_safe=`echo "dlfcn.h" | sed 'y%./+-%__p_%'`
 echo $ac_n "checking for dlfcn.h""... $ac_c" 1>&6
-echo "configure:5108: checking for dlfcn.h" >&5
+echo "configure:5123: checking for dlfcn.h" >&5
 if eval "test \"`echo '$''{'ac_cv_header_$ac_safe'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
   cat > conftest.$ac_ext <<EOF
-#line 5113 "configure"
+#line 5128 "configure"
 #include "confdefs.h"
 #include <dlfcn.h>
 EOF
 ac_try="$ac_cpp conftest.$ac_ext >/dev/null 2>conftest.out"
-{ (eval echo configure:5118: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
+{ (eval echo configure:5133: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
 ac_err=`grep -v '^ *+' conftest.out | grep -v "^conftest.${ac_ext}\$"`
 if test -z "$ac_err"; then
   rm -rf conftest*
@@ -5147,13 +5162,13 @@ esac
 
 if test $ac_cv_prog_gcc = yes; then
     echo $ac_n "checking whether ${CC-cc} needs -traditional""... $ac_c" 1>&6
-echo "configure:5151: checking whether ${CC-cc} needs -traditional" >&5
+echo "configure:5166: checking whether ${CC-cc} needs -traditional" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_gcc_traditional'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
     ac_pattern="Autoconf.*'x'"
   cat > conftest.$ac_ext <<EOF
-#line 5157 "configure"
+#line 5172 "configure"
 #include "confdefs.h"
 #include <sgtty.h>
 Autoconf TIOCGETP
@@ -5171,7 +5186,7 @@ rm -f conftest*
 
   if test $ac_cv_prog_gcc_traditional = no; then
     cat > conftest.$ac_ext <<EOF
-#line 5175 "configure"
+#line 5190 "configure"
 #include "confdefs.h"
 #include <termio.h>
 Autoconf TCGETA
@@ -5195,12 +5210,12 @@ fi
 for ac_func in lchown strerror
 do
 echo $ac_n "checking for $ac_func""... $ac_c" 1>&6
-echo "configure:5199: checking for $ac_func" >&5
+echo "configure:5214: checking for $ac_func" >&5
 if eval "test \"`echo '$''{'ac_cv_func_$ac_func'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
   cat > conftest.$ac_ext <<EOF
-#line 5204 "configure"
+#line 5219 "configure"
 #include "confdefs.h"
 /* System header to define __stub macros and hopefully few prototypes,
     which can conflict with char $ac_func(); below.  */
@@ -5223,7 +5238,7 @@ $ac_func();
 
 ; return 0; }
 EOF
-if { (eval echo configure:5227: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
+if { (eval echo configure:5242: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
   rm -rf conftest*
   eval "ac_cv_func_$ac_func=yes"
 else
@@ -5264,7 +5279,7 @@ hpux*)
 if test -z "$GNU_CC"; then
 
     echo $ac_n "checking for +Olit support""... $ac_c" 1>&6
-echo "configure:5268: checking for +Olit support" >&5
+echo "configure:5283: checking for +Olit support" >&5
 if eval "test \"`echo '$''{'ac_cv_hpux_usable_olit_option'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -5303,7 +5318,7 @@ darwin*)
 *)
     
 echo $ac_n "checking for pthread_create in -lpthreads""... $ac_c" 1>&6
-echo "configure:5307: checking for pthread_create in -lpthreads" >&5
+echo "configure:5322: checking for pthread_create in -lpthreads" >&5
 echo "
     #include <pthread.h> 
     void *foo(void *v) { return v; } 
@@ -5325,7 +5340,7 @@ echo "
         echo "$ac_t""no" 1>&6
         
 echo $ac_n "checking for pthread_create in -lpthread""... $ac_c" 1>&6
-echo "configure:5329: checking for pthread_create in -lpthread" >&5
+echo "configure:5344: checking for pthread_create in -lpthread" >&5
 echo "
     #include <pthread.h> 
     void *foo(void *v) { return v; } 
@@ -5347,7 +5362,7 @@ echo "
         echo "$ac_t""no" 1>&6
         
 echo $ac_n "checking for pthread_create in -lc_r""... $ac_c" 1>&6
-echo "configure:5351: checking for pthread_create in -lc_r" >&5
+echo "configure:5366: checking for pthread_create in -lc_r" >&5
 echo "
     #include <pthread.h> 
     void *foo(void *v) { return v; } 
@@ -5369,7 +5384,7 @@ echo "
         echo "$ac_t""no" 1>&6
         
 echo $ac_n "checking for pthread_create in -lc""... $ac_c" 1>&6
-echo "configure:5373: checking for pthread_create in -lc" >&5
+echo "configure:5388: checking for pthread_create in -lc" >&5
 echo "
     #include <pthread.h> 
     void *foo(void *v) { return v; } 
@@ -5514,7 +5529,7 @@ if test -n "$USE_PTHREADS"; then
       rm -f conftest*
    ac_cv_have_dash_pthread=no
    echo $ac_n "checking whether ${CC-cc} accepts -pthread""... $ac_c" 1>&6
-echo "configure:5518: checking whether ${CC-cc} accepts -pthread" >&5
+echo "configure:5533: checking whether ${CC-cc} accepts -pthread" >&5
    echo 'int main() { return 0; }' | cat > conftest.c
    ${CC-cc} -pthread -o conftest conftest.c > conftest.out 2>&1
    if test $? -eq 0; then
@@ -5537,7 +5552,7 @@ echo "configure:5518: checking whether ${CC-cc} accepts -pthread" >&5
 			    ac_cv_have_dash_pthreads=no
     if test "$ac_cv_have_dash_pthread" = "no"; then
 	    echo $ac_n "checking whether ${CC-cc} accepts -pthreads""... $ac_c" 1>&6
-echo "configure:5541: checking whether ${CC-cc} accepts -pthreads" >&5
+echo "configure:5556: checking whether ${CC-cc} accepts -pthreads" >&5
     	echo 'int main() { return 0; }' | cat > conftest.c
 	    ${CC-cc} -pthreads -o conftest conftest.c > conftest.out 2>&1
     	if test $? -eq 0; then
diff --git a/configure.in b/configure.in
index 656c2eb1..5da67d5a 100644
--- a/configure.in
+++ b/configure.in
@@ -243,6 +243,13 @@ AC_ARG_ENABLE(cplus,
 	    USE_CPLUS=1
       fi]) 
 
+AC_ARG_WITH(arm-kuser,
+    [  --with-arm-kuser        Use kuser helpers (Linux/ARM only)
+                          (Requires kernel 2.6.13 or later)],
+    [ if test "$withval" = "yes"; then
+	    AC_DEFINE(_PR_ARM_KUSER)
+      fi ])
+
 dnl ========================================================
 dnl = Mac OS X SDK support
 dnl ========================================================
diff --git a/pr/include/md/_linux.h b/pr/include/md/_linux.h
index c6ee449e..1350f79d 100644
--- a/pr/include/md/_linux.h
+++ b/pr/include/md/_linux.h
@@ -207,6 +207,50 @@ extern PRInt32 _PR_ppc_AtomicSet(PRInt32 *val, PRInt32 newval);
 })
 #endif
 
+#if defined(__arm__) && defined(_PR_ARM_KUSER)
+#define _PR_HAVE_ATOMIC_OPS
+#define _MD_INIT_ATOMIC()
+
+/*
+ * The kernel provides this helper function at a fixed address with a fixed
+ * ABI signature, directly callable from user space.
+ *
+ * Definition:
+ * Atomically store newval in *ptr if *ptr is equal to oldval.
+ * Return zero if *ptr was changed or non-zero if no exchange happened.
+ */
+typedef int (__kernel_cmpxchg_t)(int oldval, int newval, volatile int *ptr);
+#define __kernel_cmpxchg (*(__kernel_cmpxchg_t *)0xffff0fc0)
+
+#define _MD_ATOMIC_INCREMENT(ptr) _MD_ATOMIC_ADD(ptr, 1)
+#define _MD_ATOMIC_DECREMENT(ptr) _MD_ATOMIC_ADD(ptr, -1)
+
+static inline PRInt32 _MD_ATOMIC_ADD(PRInt32 *ptr, PRInt32 n)
+{
+    PRInt32 ov, nv;
+    volatile PRInt32 *vp = ptr;
+
+    do {
+        ov = *vp;
+        nv = ov + n;
+    } while (__kernel_cmpxchg(ov, nv, vp));
+
+    return nv;
+}
+
+static inline PRInt32 _MD_ATOMIC_SET(PRInt32 *ptr, PRInt32 nv)
+{
+    PRInt32 ov;
+    volatile PRInt32 *vp = ptr;
+
+    do {
+        ov = *vp;
+    } while (__kernel_cmpxchg(ov, nv, vp));
+
+    return ov;
+}
+#endif
+
 #define USE_SETJMP
 #if defined(__GLIBC__) && __GLIBC__ >= 2
 #define _PR_POLL_AVAILABLE