cselib.h revision 96489
1/* Common subexpression elimination for GNU compiler. 2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 3 1999 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, 59 Temple Place - Suite 330, Boston, MA 2002111-1307, USA. */ 21 22/* Describe a value. */ 23typedef struct cselib_val_struct 24{ 25 /* The hash value. */ 26 unsigned int value; 27 union 28 { 29 /* A VALUE rtx that points back to this structure. */ 30 rtx val_rtx; 31 /* Used to keep a list of free cselib_val structures. */ 32 struct cselib_val_struct *next_free; 33 } 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} cselib_val; 42 43/* A list of rtl expressions that hold the same value. */ 44struct elt_loc_list 45{ 46 /* Next element in the list. */ 47 struct elt_loc_list *next; 48 /* An rtl expression that holds the value. */ 49 rtx loc; 50 /* The insn that made the equivalence. */ 51 rtx setting_insn; 52}; 53 54/* A list of cselib_val structures. */ 55struct elt_list 56{ 57 struct elt_list *next; 58 cselib_val *elt; 59}; 60 61extern cselib_val *cselib_lookup PARAMS ((rtx, enum machine_mode, int)); 62extern void cselib_update_varray_sizes PARAMS ((void)); 63extern void cselib_init PARAMS ((void)); 64extern void cselib_finish PARAMS ((void)); 65extern void cselib_process_insn PARAMS ((rtx)); 66extern int rtx_equal_for_cselib_p PARAMS ((rtx, rtx)); 67extern int references_value_p PARAMS ((rtx, int)); 68extern rtx cselib_subst_to_values PARAMS ((rtx)); 69