--- a/common/autoconf/boot-jdk.m4	Tue Oct 20 08:24:24 2015 -0700
+++ b/common/autoconf/boot-jdk.m4	Tue Oct 20 10:33:25 2015 -0700
@@ -305,6 +305,16 @@
   BOOT_JDK_SOURCETARGET="-source 8 -target 8"
   AC_SUBST(BOOT_JDK_SOURCETARGET)
   AC_SUBST(JAVAC_FLAGS)
+
+  # Check if the boot jdk is 32 or 64 bit
+  if "$JAVA" -d64 -version > /dev/null 2>&1; then
+    BOOT_JDK_BITS="64"
+  else
+    BOOT_JDK_BITS="32"
+  fi
+  AC_MSG_CHECKING([if Boot JDK is 32 or 64 bits])
+  AC_MSG_RESULT([$BOOT_JDK_BITS])
+  AC_SUBST(BOOT_JDK_BITS)
 ])
 
 AC_DEFUN_ONCE([BOOTJDK_SETUP_BOOT_JDK_ARGUMENTS],
@@ -341,7 +351,7 @@
   # Maximum amount of heap memory.
   # Maximum stack size.
   JVM_MAX_HEAP=`expr $MEMORY_SIZE / 2`
-  if test "x$BUILD_NUM_BITS" = x32; then
+  if test "x$BOOT_JDK_BITS" = "x32"; then
     if test "$JVM_MAX_HEAP" -gt "1100"; then
       JVM_MAX_HEAP=1100
     elif test "$JVM_MAX_HEAP" -lt "512"; then
@@ -349,10 +359,7 @@
     fi
     STACK_SIZE=768
   else
-    # Running Javac on a JVM on a 64-bit machine, takes more space since 64-bit
-    # pointers are used. Apparently, we need to increase the heap and stack
-    # space for the jvm. More specifically, when running javac to build huge
-    # jdk batch
+    # Running a 64 bit JVM allows for and requires a bigger heap
     if test "$JVM_MAX_HEAP" -gt "1600"; then
       JVM_MAX_HEAP=1600
     elif test "$JVM_MAX_HEAP" -lt "512"; then

--- a/common/autoconf/generated-configure.sh	Tue Oct 20 08:24:24 2015 -0700
+++ b/common/autoconf/generated-configure.sh	Tue Oct 20 10:33:25 2015 -0700
@@ -815,6 +815,7 @@
 JAXP_TOPDIR
 CORBA_TOPDIR
 LANGTOOLS_TOPDIR
+BOOT_JDK_BITS
 JAVAC_FLAGS
 BOOT_JDK_SOURCETARGET
 JARSIGNER
@@ -4587,7 +4588,7 @@
 #CUSTOM_AUTOCONF_INCLUDE
 
 # Do not change or remove the following line, it is needed for consistency checks:
-DATE_WHEN_GENERATED=1444643341
+DATE_WHEN_GENERATED=1445354942
 
 ###############################################################################
 #
@@ -26920,6 +26921,18 @@
 
 
 
+  # Check if the boot jdk is 32 or 64 bit
+  if "$JAVA" -d64 -version > /dev/null 2>&1; then
+    BOOT_JDK_BITS="64"
+  else
+    BOOT_JDK_BITS="32"
+  fi
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking if Boot JDK is 32 or 64 bits" >&5
+$as_echo_n "checking if Boot JDK is 32 or 64 bits... " >&6; }
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $BOOT_JDK_BITS" >&5
+$as_echo "$BOOT_JDK_BITS" >&6; }
+
+
 
 ###############################################################################
 #
@@ -53099,7 +53112,7 @@
   # Maximum amount of heap memory.
   # Maximum stack size.
   JVM_MAX_HEAP=`expr $MEMORY_SIZE / 2`
-  if test "x$BUILD_NUM_BITS" = x32; then
+  if test "x$BOOT_JDK_BITS" = "x32"; then
     if test "$JVM_MAX_HEAP" -gt "1100"; then
       JVM_MAX_HEAP=1100
     elif test "$JVM_MAX_HEAP" -lt "512"; then
@@ -53107,10 +53120,7 @@
     fi
     STACK_SIZE=768
   else
-    # Running Javac on a JVM on a 64-bit machine, takes more space since 64-bit
-    # pointers are used. Apparently, we need to increase the heap and stack
-    # space for the jvm. More specifically, when running javac to build huge
-    # jdk batch
+    # Running a 64 bit JVM allows for and requires a bigger heap
     if test "$JVM_MAX_HEAP" -gt "1600"; then
       JVM_MAX_HEAP=1600
     elif test "$JVM_MAX_HEAP" -lt "512"; then