--- old/make/autoconf/flags-cflags.m4	2018-06-08 14:40:35.751835784 -0700
+++ new/make/autoconf/flags-cflags.m4	2018-06-08 14:40:35.527835792 -0700
@@ -764,6 +764,26 @@
     $1_WARNING_CFLAGS_JVM="-Wno-format-zero-length -Wtype-limits -Wuninitialized"
   fi
 
+  case $TOOLCHAIN_TYPE in
+    gcc)
+      $2NO_SPECULATIVE_CTI_CFLAGS="-mindirect-branch=thunk \
+          -mfunction-return=thunk -mindirect-branch-register"
+      ;;
+    microsoft)
+      $2NO_SPECULATIVE_CTI_CFLAGS="-Qspectre"
+      ;;
+    *)
+      $2NO_SPECULATIVE_CTI_CFLAGS=""
+      ;;
+  esac
+  if test -n "${$2NO_SPECULATIVE_CTI_CFLAGS}"; then
+    FLAGS_COMPILER_CHECK_ARGUMENTS(ARGUMENT: [${$2NO_SPECULATIVE_CTI_CFLAGS}],
+        IF_FALSE: [
+          $2NO_SPECULATIVE_CTI_CFLAGS=""
+        ]
+    )
+  fi
+
   # EXPORT to API
   CFLAGS_JVM_COMMON="$ALWAYS_CFLAGS_JVM $ALWAYS_DEFINES_JVM $TOOLCHAIN_CFLAGS_JVM \
       $OS_CFLAGS $OS_CFLAGS_JVM $CFLAGS_OS_DEF_JVM $DEBUG_CFLAGS_JVM \
@@ -782,8 +802,10 @@
   CFLAGS_JDK_COMMON_CXXONLY="$ALWAYS_DEFINES_JDK_CXXONLY $TOOLCHAIN_CFLAGS_JDK_CXXONLY \
       $WARNING_CFLAGS_JDK_CXXONLY ${$2EXTRA_CXXFLAGS}"
 
-  $1_CFLAGS_JVM="${$1_DEFINES_CPU_JVM} ${$1_CFLAGS_CPU} ${$1_CFLAGS_CPU_JVM} ${$1_TOOLCHAIN_CFLAGS} ${$1_WARNING_CFLAGS_JVM}"
-  $1_CFLAGS_JDK="${$1_DEFINES_CPU_JDK} ${$1_CFLAGS_CPU} ${$1_CFLAGS_CPU_JDK} ${$1_TOOLCHAIN_CFLAGS}"
+  $1_CFLAGS_JVM="${$1_DEFINES_CPU_JVM} ${$1_CFLAGS_CPU} ${$1_CFLAGS_CPU_JVM} \
+      ${$1_TOOLCHAIN_CFLAGS} ${$1_WARNING_CFLAGS_JVM}"
+  $1_CFLAGS_JDK="${$1_DEFINES_CPU_JDK} ${$1_CFLAGS_CPU} ${$1_CFLAGS_CPU_JDK} \
+      ${$1_TOOLCHAIN_CFLAGS}"
 
   $2JVM_CFLAGS="$CFLAGS_JVM_COMMON ${$1_CFLAGS_JVM} ${$2EXTRA_CXXFLAGS}"
 
@@ -797,6 +819,7 @@
   AC_SUBST($2CFLAGS_JDKEXE)
   AC_SUBST($2CXXFLAGS_JDKLIB)
   AC_SUBST($2CXXFLAGS_JDKEXE)
+  AC_SUBST($2NO_SPECULATIVE_CTI_CFLAGS)
 ])
 
 # FLAGS_SETUP_GCC6_COMPILER_FLAGS([PREFIX])