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 5This file is part of GCC. 6 7GCC is free software; you can redistribute it and/or modify it under 8the terms of the GNU General Public License as published by the Free 9Software Foundation; either version 2, or (at your option) any later 10version. 11 12GCC is distributed in the hope that it will be useful, but WITHOUT ANY 13WARRANTY; without even the implied warranty of MERCHANTABILITY or 14FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 15for more details. 16 17You should have received a copy of the GNU General Public License 18along with GCC; see the file COPYING. If not, write to the Free 19Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 2002110-1301, USA. */ 21 22/* Describe a value. */ 23typedef 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. */ 46struct 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. */ 59struct elt_list GTY(()) 60{ 61 struct elt_list *next; 62 cselib_val *elt; 63}; 64 65extern cselib_val *cselib_lookup (rtx, enum machine_mode, int); 66extern void cselib_init (bool record_memory); 67extern void cselib_clear_table (void); 68extern void cselib_finish (void); 69extern void cselib_process_insn (rtx); 70extern enum machine_mode cselib_reg_set_mode (rtx); 71extern int rtx_equal_for_cselib_p (rtx, rtx); 72extern int references_value_p (rtx, int); 73extern rtx cselib_subst_to_values (rtx); 74extern void cselib_invalidate_rtx (rtx); 75