+#if defined(sparc_HOST_ARCH)
+// Don't use REG_base or R1 for gct on SPARC because they're getting clobbered
+// by something else. Not sure what yet. -- BL 2009/01/03
+
+extern __thread gc_thread* gct;
+#define DECLARE_GCT __thread gc_thread* gct;
+
+#elif defined(REG_Base) && !defined(i386_HOST_ARCH)