+/* Target-dependent globals. */
+struct GTY(()) target_rtl {
+ /* All references to the hard registers in global_rtl_index go through
+ these unique rtl objects. On machines where the frame-pointer and
+ arg-pointer are the same register, they use the same unique object.
+
+ After register allocation, other rtl objects which used to be pseudo-regs
+ may be clobbered to refer to the frame-pointer register.
+ But references that were originally to the frame-pointer can be
+ distinguished from the others because they contain frame_pointer_rtx.
+
+ When to use frame_pointer_rtx and hard_frame_pointer_rtx is a little
+ tricky: until register elimination has taken place hard_frame_pointer_rtx
+ should be used if it is being set, and frame_pointer_rtx otherwise. After
+ register elimination hard_frame_pointer_rtx should always be used.
+ On machines where the two registers are same (most) then these are the
+ same. */
+ rtx x_global_rtl[GR_MAX];
+
+ /* A unique representation of (REG:Pmode PIC_OFFSET_TABLE_REGNUM). */
+ rtx x_pic_offset_table_rtx;
+
+ /* A unique representation of (REG:Pmode RETURN_ADDRESS_POINTER_REGNUM).
+ This is used to implement __builtin_return_address for some machines;
+ see for instance the MIPS port. */
+ rtx x_return_address_pointer_rtx;
+
+ /* Commonly used RTL for hard registers. These objects are not
+ necessarily unique, so we allocate them separately from global_rtl.
+ They are initialized once per compilation unit, then copied into
+ regno_reg_rtx at the beginning of each function. */
+ rtx x_initial_regno_reg_rtx[FIRST_PSEUDO_REGISTER];
+
+ /* A sample (mem:M stack_pointer_rtx) rtx for each mode M. */
+ rtx x_top_of_stack[MAX_MACHINE_MODE];
+
+ /* Static hunks of RTL used by the aliasing code; these are treated
+ as persistent to avoid unnecessary RTL allocations. */
+ rtx x_static_reg_base_value[FIRST_PSEUDO_REGISTER];
+};
+
+extern GTY(()) struct target_rtl default_target_rtl;
+#if SWITCHABLE_TARGET
+extern struct target_rtl *this_target_rtl;
+#else
+#define this_target_rtl (&default_target_rtl)
+#endif
+
+#define global_rtl \
+ (this_target_rtl->x_global_rtl)
+#define pic_offset_table_rtx \
+ (this_target_rtl->x_pic_offset_table_rtx)
+#define return_address_pointer_rtx \
+ (this_target_rtl->x_return_address_pointer_rtx)
+#define top_of_stack \
+ (this_target_rtl->x_top_of_stack)