diff -r 86030362b0c5 common/autoconf/hotspot-spec.gmk.in
--- openjdk/common/autoconf/hotspot-spec.gmk.in	Mon Feb 29 06:45:20 2016 +0000
+++ openjdk/common/autoconf/hotspot-spec.gmk.in	Fri Mar 11 18:01:42 2016 +0000
@@ -109,7 +109,7 @@
 MT:=@HOTSPOT_MT@
 RC:=@HOTSPOT_RC@
 
-EXTRA_CFLAGS=@LEGACY_EXTRA_CFLAGS@
+EXTRA_CFLAGS=@LEGACY_EXTRA_CFLAGS@ $(NO_NULL_POINTER_CHECK_FLAG) $(NO_LIFETIME_DSE_CFLAG) $(CXXSTD_CXXFLAG)
 EXTRA_CXXFLAGS=@LEGACY_EXTRA_CXXFLAGS@
 EXTRA_LDFLAGS=@LEGACY_EXTRA_LDFLAGS@
 
diff -r 86030362b0c5 common/autoconf/spec.gmk.in
--- openjdk/common/autoconf/spec.gmk.in	Mon Feb 29 06:45:20 2016 +0000
+++ openjdk/common/autoconf/spec.gmk.in	Fri Mar 11 18:01:42 2016 +0000
@@ -320,6 +320,10 @@
 C_FLAG_DEPS:=@C_FLAG_DEPS@
 CXX_FLAG_DEPS:=@CXX_FLAG_DEPS@
 
+NO_NULL_POINTER_CHECK_FLAG=@NO_NULL_POINTER_CHECK_CFLAG@
+NO_LIFETIME_DSE_CFLAG=@NO_LIFETIME_DSE_CFLAG@
+CXXSTD_CXXFLAG=@CXXSTD_CXXFLAG@
+
 # Tools that potentially need to be cross compilation aware.
 CC:=@FIXPATH@ @CCACHE@ @CC@
 
diff -r 86030362b0c5 common/autoconf/toolchain.m4
--- openjdk/common/autoconf/toolchain.m4	Mon Feb 29 06:45:20 2016 +0000
+++ openjdk/common/autoconf/toolchain.m4	Fri Mar 11 18:01:42 2016 +0000
@@ -784,6 +784,10 @@
             CFLAGS_DEBUG_SYMBOLS="-g1"
             CXXFLAGS_DEBUG_SYMBOLS="-g1"
           fi
+	  CXXSTD_CXXFLAG="-std=gnu++98"
+	  TOOLCHAIN_CXX_COMPILER_CHECK_ARGUMENTS([$CXXSTD_CXXFLAG -Werror], [], [CXXSTD_CXXFLAG=""])
+	  CXXFLAGS_JDK="${CXXFLAGS_JDK} ${CXXSTD_CXXFLAG}"
+	  AC_SUBST([CXXSTD_CXXFLAG])
           ;;
         ossc )
           #
@@ -973,6 +977,16 @@
           CFLAGS_JDK="${CFLAGS_JDK} -fno-strict-aliasing"
           ;;
       esac
+      # These flags are required for GCC 6 builds but may not be available on earlier versions
+      NO_NULL_POINTER_CHECK_CFLAG="-fno-delete-null-pointer-checks"
+      TOOLCHAIN_COMPILER_CHECK_ARGUMENTS([$NO_NULL_POINTER_CHECK_CFLAG -Werror], [],
+    					 [NO_NULL_POINTER_CHECK_CFLAG=""])
+      AC_SUBST([NO_NULL_POINTER_CHECK_CFLAG])
+      NO_LIFETIME_DSE_CFLAG="-fno-lifetime-dse"
+      TOOLCHAIN_COMPILER_CHECK_ARGUMENTS([$NO_LIFETIME_DSE_CFLAG -Werror], [],
+    					 [NO_LIFETIME_DSE_CFLAG=""])
+      CFLAGS_JDK="${CFLAGS_JDK} ${NO_NULL_POINTER_CHECK_CFLAG} ${NO_LIFETIME_DSE_CFLAG}"
+      AC_SUBST([NO_LIFETIME_DSE_CFLAG])
       ;;
     ossc )
       CCXXFLAGS_JDK="$CCXXFLAGS $CCXXFLAGS_JDK -DTRACING -DMACRO_MEMSYS_OPS -DBREAKPTS"
@@ -1200,9 +1214,9 @@
 #                                   [RUN-IF-FALSE])
 # ------------------------------------------------------------
 # Check that the c and c++ compilers support an argument
-AC_DEFUN([TOOLCHAIN_COMPILER_CHECK_ARGUMENTS],
+AC_DEFUN([TOOLCHAIN_C_COMPILER_CHECK_ARGUMENTS],
 [
-  AC_MSG_CHECKING([if compiler supports "$1"])
+  AC_MSG_CHECKING([if the C compiler supports "$1"])
   supports=yes
 
   saved_cflags="$CFLAGS"
@@ -1213,6 +1227,19 @@
   AC_LANG_POP([C])
   CFLAGS="$saved_cflags"
 
+  AC_MSG_RESULT([$supports])
+  if test "x$supports" = "xyes" ; then
+    m4_ifval([$2], [$2], [:])
+  else
+    m4_ifval([$3], [$3], [:])
+  fi
+])
+
+AC_DEFUN([TOOLCHAIN_CXX_COMPILER_CHECK_ARGUMENTS],
+[
+  AC_MSG_CHECKING([if the C++ compiler supports "$1"])
+  supports=yes
+
   saved_cxxflags="$CXXFLAGS"
   CXXFLAGS="$CXXFLAG $1"
   AC_LANG_PUSH([C++])
@@ -1220,7 +1247,28 @@
       [supports=no])
   AC_LANG_POP([C++])
   CXXFLAGS="$saved_cxxflags"
+  
+  AC_MSG_RESULT([$supports])
+  if test "x$supports" = "xyes" ; then
+    m4_ifval([$2], [$2], [:])
+  else
+    m4_ifval([$3], [$3], [:])
+  fi
+])
 
+# TOOLCHAIN_COMPILER_CHECK_ARGUMENTS(ARGUMENT: [ARGUMENT], IF_TRUE: [RUN-IF-TRUE],
+#                                   IF_FALSE: [RUN-IF-FALSE])
+# ------------------------------------------------------------
+# Check that the c and c++ compilers support an argument
+AC_DEFUN([TOOLCHAIN_COMPILER_CHECK_ARGUMENTS],
+[
+  TOOLCHAIN_C_COMPILER_CHECK_ARGUMENTS([$1], [C_COMP_SUPPORTS="yes"], [C_COMP_SUPPORTS="no"])
+  TOOLCHAIN_CXX_COMPILER_CHECK_ARGUMENTS([$1], [CXX_COMP_SUPPORTS="yes"], [CXX_COMP_SUPPORTS="no"])
+
+  AC_MSG_CHECKING([if both compilers support "$1"])
+  supports=no
+  if test "x$C_COMP_SUPPORTS" = "xyes" -a "x$CXX_COMP_SUPPORTS" = "xyes"; then supports=yes; fi
+  
   AC_MSG_RESULT([$supports])
   if test "x$supports" = "xyes" ; then
     m4_ifval([$2], [$2], [:])