+#define CALLER_SAVE_REGS 0x0007ffff
+#define PREFERRED_REG_FIRST 19
+#define PREFERRED_REG_LAST 27
+
+#define DRC_DBG_REGMASK 3 // others done by do_insn_cmp_arm64
+#define do_insn_cmp do_insn_cmp_arm64
+
+// stack space
+#define SSP_CALLEE_REGS (8*12) // new_dyna_start caller's
+#define SSP_CALLER_REGS (8*20)
+#define SSP_ALL (SSP_CALLEE_REGS+SSP_CALLER_REGS)
+
+#define TARGET_SIZE_2 24 // 2^24 = 16 megabytes
+