1 /* Common subexpression elimination for GNU compiler. 2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 3 1998, 1999, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 4 Free Software Foundation, Inc. 5 6 This file is part of GCC. 7 8 GCC is free software; you can redistribute it and/or modify it under 9 the terms of the GNU General Public License as published by the Free 10 Software Foundation; either version 3, or (at your option) any later 11 version. 12 13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY 14 WARRANTY; without even the implied warranty of MERCHANTABILITY or 15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 16 for more details. 17 18 You should have received a copy of the GNU General Public License 19 along with GCC; see the file COPYING3. If not see 20 <http://www.gnu.org/licenses/>. */ 21 22 /* Describe a value. */ 23 typedef struct GTY(()) cselib_val_struct { 24 /* The hash value. */ 25 unsigned int hash; 26 27 /* A unique id assigned to values. */ 28 int uid; 29 30 /* A VALUE rtx that points back to this structure. */ 31 rtx val_rtx; 32 33 /* All rtl expressions that hold this value at the current time during a 34 scan. */ 35 struct elt_loc_list *locs; 36 37 /* If this value is used as an address, points to a list of values that 38 use it as an address in a MEM. */ 39 struct elt_list *addr_list; 40 41 struct cselib_val_struct *next_containing_mem; 42 } cselib_val; 43 44 /* A list of rtl expressions that hold the same value. */ 45 struct GTY(()) elt_loc_list { 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. */ 55 struct GTY(()) elt_list { 56 struct elt_list *next; 57 cselib_val *elt; 58 }; 59 60 /* Describe a single set that is part of an insn. */ 61 struct cselib_set 62 { 63 rtx src; 64 rtx dest; 65 cselib_val *src_elt; 66 cselib_val *dest_addr_elt; 67 }; 68 69 enum cselib_record_what 70 { 71 CSELIB_RECORD_MEMORY = 1, 72 CSELIB_PRESERVE_CONSTANTS = 2 73 }; 74 75 extern void (*cselib_discard_hook) (cselib_val *); 76 extern void (*cselib_record_sets_hook) (rtx insn, struct cselib_set *sets, 77 int n_sets); 78 79 extern cselib_val *cselib_lookup (rtx, enum machine_mode, int); 80 extern cselib_val *cselib_lookup_from_insn (rtx, enum machine_mode, int, rtx); 81 extern void cselib_init (int); 82 extern void cselib_clear_table (void); 83 extern void cselib_finish (void); 84 extern void cselib_process_insn (rtx); 85 extern enum machine_mode cselib_reg_set_mode (const_rtx); 86 extern int rtx_equal_for_cselib_p (rtx, rtx); 87 extern int references_value_p (const_rtx, int); 88 extern rtx cselib_expand_value_rtx (rtx, bitmap, int); 89 typedef rtx (*cselib_expand_callback)(rtx, bitmap, int, void *); 90 extern rtx cselib_expand_value_rtx_cb (rtx, bitmap, int, 91 cselib_expand_callback, void *); 92 extern bool cselib_dummy_expand_value_rtx_cb (rtx, bitmap, int, 93 cselib_expand_callback, void *); 94 extern rtx cselib_subst_to_values (rtx); 95 extern void cselib_invalidate_rtx (rtx); 96 97 extern void cselib_reset_table (unsigned int); 98 extern unsigned int cselib_get_next_uid (void); 99 extern void cselib_preserve_value (cselib_val *); 100 extern bool cselib_preserved_value_p (cselib_val *); 101 extern void cselib_preserve_only_values (void); 102 extern void cselib_preserve_cfa_base_value (cselib_val *, unsigned int); 103 104 extern void dump_cselib_table (FILE *); 105