diff -r e885c762cedd -r 584dc2e95e04 common/autoconf/platform.m4
--- a/common/autoconf/platform.m4	Thu Sep 05 10:58:25 2013 -0700
+++ b/common/autoconf/platform.m4	Thu Sep 12 12:29:17 2013 -0700
@@ -114,6 +114,11 @@
       VAR_OS_API=winapi
       VAR_OS_ENV=windows.msys
       ;;
+    *aix*)
+      VAR_OS=aix
+      VAR_OS_API=posix
+      VAR_OS_ENV=aix
+      ;;
     *)
       AC_MSG_ERROR([unsupported operating system $1])
       ;;
@@ -412,16 +417,17 @@
 [
   # keep track of c/cxx flags that we added outselves...
   #   to prevent emitting warning...
-  TARGET_BITS_FLAG="-m${OPENJDK_TARGET_CPU_BITS}"
-  AC_SUBST(TARGET_BITS_FLAG)
+  ADDED_CFLAGS=" ${COMPILER_TARGET_BITS_FLAG}${OPENJDK_TARGET_CPU_BITS}"
+  ADDED_CXXFLAGS=" ${COMPILER_TARGET_BITS_FLAG}${OPENJDK_TARGET_CPU_BITS}"
+  ADDED_LDFLAGS=" ${COMPILER_TARGET_BITS_FLAG}${OPENJDK_TARGET_CPU_BITS}"
 
-  CFLAGS="${CFLAGS} ${TARGET_BITS_FLAG}"
-  CXXFLAGS="${CXXFLAGS} ${TARGET_BITS_FLAG}"
-  LDFLAGS="${LDFLAGS} ${TARGET_BITS_FLAG}"
+  CFLAGS="${CFLAGS}${ADDED_CFLAGS}"
+  CXXFLAGS="${CXXFLAGS}${ADDED_CXXFLAGS}"
+  LDFLAGS="${LDFLAGS}${ADDED_LDFLAGS}"
 
-  CFLAGS_JDK="${CFLAGS_JDK} ${TARGET_BITS_FLAG}"
-  CXXFLAGS_JDK="${CXXFLAGS_JDK} ${TARGET_BITS_FLAG}"
-  LDFLAGS_JDK="${LDFLAGS_JDK} ${TARGET_BITS_FLAG}"
+  CFLAGS_JDK="${CFLAGS_JDK}${ADDED_CFLAGS}"
+  CXXFLAGS_JDK="${CXXFLAGS_JDK}${ADDED_CXXFLAGS}"
+  LDFLAGS_JDK="${LDFLAGS_JDK}${ADDED_LDFLAGS}"
 ])
 
 AC_DEFUN_ONCE([PLATFORM_SETUP_OPENJDK_TARGET_BITS],
@@ -433,8 +439,9 @@
 # is made at runtime.)
 #
 
-if test "x$OPENJDK_TARGET_OS" = xsolaris; then
-  # Always specify -m flags on Solaris
+if test "x$OPENJDK_TARGET_OS" = xsolaris || test "x$OPENJDK_TARGET_OS" = xaix; then
+  # Always specify -m flag on Solaris
+  # And -q on AIX because otherwise the compiler produces 32-bit objects by default
   PLATFORM_SET_COMPILER_TARGET_BITS_FLAGS
 elif test "x$COMPILE_TYPE" = xreduced; then
   if test "x$OPENJDK_TARGET_OS" != xwindows; then
@@ -456,19 +463,34 @@
 
 AC_CHECK_SIZEOF([int *], [1111])
 
-if test "x$SIZEOF_INT_P" != "x$ac_cv_sizeof_int_p"; then
-  # Workaround autoconf bug, see http://lists.gnu.org/archive/html/autoconf/2010-07/msg00004.html
-  SIZEOF_INT_P="$ac_cv_sizeof_int_p"
-fi
-
-if test "x$SIZEOF_INT_P" = x; then 
+# AC_CHECK_SIZEOF defines 'ac_cv_sizeof_int_p' to hold the number of bytes used by an 'int*'
+if test "x$ac_cv_sizeof_int_p" = x; then
     # The test failed, lets stick to the assumed value.
     AC_MSG_WARN([The number of bits in the target could not be determined, using $OPENJDK_TARGET_CPU_BITS.])
 else
-    TESTED_TARGET_CPU_BITS=`expr 8 \* $SIZEOF_INT_P`
+    TESTED_TARGET_CPU_BITS=`expr 8 \* $ac_cv_sizeof_int_p`
 
     if test "x$TESTED_TARGET_CPU_BITS" != "x$OPENJDK_TARGET_CPU_BITS"; then
-        AC_MSG_ERROR([The tested number of bits in the target ($TESTED_TARGET_CPU_BITS) differs from the number of bits expected to be found in the target ($OPENJDK_TARGET_CPU_BITS)])
+        # This situation may happen on 64-bit platforms where the compiler by default only generates 32-bit objects
+        # Let's try to implicitely set the compilers target architecture and retry the test
+        AC_MSG_NOTICE([The tested number of bits in the target ($TESTED_TARGET_CPU_BITS) differs from the number of bits expected to be found in the target ($OPENJDK_TARGET_CPU_BITS).])
+        AC_MSG_NOTICE([I'll retry after setting the platforms compiler target bits flag to ${COMPILER_TARGET_BITS_FLAG}${OPENJDK_TARGET_CPU_BITS}])
+        PLATFORM_SET_COMPILER_TARGET_BITS_FLAGS
+
+        # We have to unset 'ac_cv_sizeof_int_p' first, otherwise AC_CHECK_SIZEOF will use the previously cached value!
+        unset ac_cv_sizeof_int_p
+	# And we have to undef the definition of SIZEOF_INT_P in confdefs.h by the previous invocation of AC_CHECK_SIZEOF
+	cat >>confdefs.h <<_ACEOF
+#undef SIZEOF_INT_P
+_ACEOF
+
+        AC_CHECK_SIZEOF([int *], [1111])
+
+        TESTED_TARGET_CPU_BITS=`expr 8 \* $ac_cv_sizeof_int_p`
+
+        if test "x$TESTED_TARGET_CPU_BITS" != "x$OPENJDK_TARGET_CPU_BITS"; then
+            AC_MSG_ERROR([The tested number of bits in the target ($TESTED_TARGET_CPU_BITS) differs from the number of bits expected to be found in the target ($OPENJDK_TARGET_CPU_BITS)])
+        fi
     fi
 fi