1 /* Common subexpression elimination for GNU compiler. 2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 3 1999, 2003, 2004, 2005 Free Software Foundation, Inc. 4 5 This file is part of GCC. 6 7 GCC is free software; you can redistribute it and/or modify it under 8 the terms of the GNU General Public License as published by the Free 9 Software Foundation; either version 2, or (at your option) any later 10 version. 11 12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY 13 WARRANTY; without even the implied warranty of MERCHANTABILITY or 14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 15 for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with GCC; see the file COPYING. If not, write to the Free 19 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 20 02110-1301, USA. */ 21 22 /* Describe a value. */ 23 typedef struct cselib_val_struct GTY(()) 24 { 25 /* The hash value. */ 26 unsigned int value; 27 union cselib_val_u 28 { 29 /* A VALUE rtx that points back to this structure. */ 30 rtx GTY ((tag ("1"))) val_rtx; 31 /* Used to keep a list of free cselib_val structures. */ 32 struct cselib_val_struct * GTY ((skip)) next_free; 33 } GTY ((desc ("1"))) u; 34 35 /* All rtl expressions that hold this value at the current time during a 36 scan. */ 37 struct elt_loc_list *locs; 38 /* If this value is used as an address, points to a list of values that 39 use it as an address in a MEM. */ 40 struct elt_list *addr_list; 41 42 struct cselib_val_struct *next_containing_mem; 43 } cselib_val; 44 45 /* A list of rtl expressions that hold the same value. */ 46 struct elt_loc_list GTY(()) 47 { 48 /* Next element in the list. */ 49 struct elt_loc_list *next; 50 /* An rtl expression that holds the value. */ 51 rtx loc; 52 /* The insn that made the equivalence. */ 53 rtx setting_insn; 54 /* True when setting insn is inside libcall. */ 55 bool in_libcall; 56 }; 57 58 /* A list of cselib_val structures. */ 59 struct elt_list GTY(()) 60 { 61 struct elt_list *next; 62 cselib_val *elt; 63 }; 64 65 extern cselib_val *cselib_lookup (rtx, enum machine_mode, int); 66 extern void cselib_init (bool record_memory); 67 extern void cselib_clear_table (void); 68 extern void cselib_finish (void); 69 extern void cselib_process_insn (rtx); 70 extern enum machine_mode cselib_reg_set_mode (rtx); 71 extern int rtx_equal_for_cselib_p (rtx, rtx); 72 extern int references_value_p (rtx, int); 73 extern rtx cselib_subst_to_values (rtx); 74 extern void cselib_invalidate_rtx (rtx); 75