+ return new_rtx;
+}
+\f
+/* A fake decl that is used as the MEM_EXPR of spill slots. */
+static GTY(()) tree spill_slot_decl;
+
+tree
+get_spill_slot_decl (bool force_build_p)
+{
+ tree d = spill_slot_decl;
+ rtx rd;
+
+ if (d || !force_build_p)
+ return d;
+
+ d = build_decl (VAR_DECL, get_identifier ("%sfp"), void_type_node);
+ DECL_ARTIFICIAL (d) = 1;
+ DECL_IGNORED_P (d) = 1;
+ TREE_USED (d) = 1;
+ TREE_THIS_NOTRAP (d) = 1;
+ spill_slot_decl = d;
+
+ rd = gen_rtx_MEM (BLKmode, frame_pointer_rtx);
+ MEM_NOTRAP_P (rd) = 1;
+ MEM_ATTRS (rd) = get_mem_attrs (new_alias_set (), d, const0_rtx,
+ NULL_RTX, 0, BLKmode);
+ SET_DECL_RTL (d, rd);
+
+ return d;
+}
+
+/* Given MEM, a result from assign_stack_local, fill in the memory
+ attributes as appropriate for a register allocator spill slot.
+ These slots are not aliasable by other memory. We arrange for
+ them all to use a single MEM_EXPR, so that the aliasing code can
+ work properly in the case of shared spill slots. */
+
+void
+set_mem_attrs_for_spill (rtx mem)
+{
+ alias_set_type alias;
+ rtx addr, offset;
+ tree expr;
+
+ expr = get_spill_slot_decl (true);
+ alias = MEM_ALIAS_SET (DECL_RTL (expr));
+
+ /* We expect the incoming memory to be of the form:
+ (mem:MODE (plus (reg sfp) (const_int offset)))
+ with perhaps the plus missing for offset = 0. */
+ addr = XEXP (mem, 0);
+ offset = const0_rtx;
+ if (GET_CODE (addr) == PLUS
+ && GET_CODE (XEXP (addr, 1)) == CONST_INT)
+ offset = XEXP (addr, 1);
+
+ MEM_ATTRS (mem) = get_mem_attrs (alias, expr, offset,
+ MEM_SIZE (mem), MEM_ALIGN (mem),
+ GET_MODE (mem));
+ MEM_NOTRAP_P (mem) = 1;