--- a/src/gcc/config/i386/gnu.h
+++ b/src/gcc/config/i386/gnu.h
@@ -39,9 +39,16 @@
 
 /* Not supported yet.  */
 # undef TARGET_THREAD_SSP_OFFSET
+/* i386 glibc provides __stack_chk_guard in %gs:0x14.  */
+/*
+#define TARGET_THREAD_SSP_OFFSET        0x14
+ */
 
-/* Not supported yet.  */
-# undef TARGET_CAN_SPLIT_STACK
-# undef TARGET_THREAD_SPLIT_STACK_OFFSET
-
+/* We only build the -fsplit-stack support in libgcc if the
+   assembler has full support for the CFI directives.  */
+#if HAVE_GAS_CFI_PERSONALITY_DIRECTIVE
+#define TARGET_CAN_SPLIT_STACK
+#endif
+/* We steal the last transactional memory word.  */
+#define TARGET_THREAD_SPLIT_STACK_OFFSET 0x30
 #endif