1 /* Communication between reload.c and reload1.c.
2 Copyright (C) 1987, 91-95, 97, 1998 Free Software Foundation, Inc.
4 This file is part of GNU CC.
6 GNU CC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU CC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU CC; see the file COPYING. If not, write to
18 the Free Software Foundation, 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
22 /* If secondary reloads are the same for inputs and outputs, define those
25 #ifdef SECONDARY_RELOAD_CLASS
26 #define SECONDARY_INPUT_RELOAD_CLASS(CLASS, MODE, X) \
27 SECONDARY_RELOAD_CLASS (CLASS, MODE, X)
28 #define SECONDARY_OUTPUT_RELOAD_CLASS(CLASS, MODE, X) \
29 SECONDARY_RELOAD_CLASS (CLASS, MODE, X)
32 /* If either macro is defined, show that we need secondary reloads. */
33 #if defined(SECONDARY_INPUT_RELOAD_CLASS) || defined(SECONDARY_OUTPUT_RELOAD_CLASS)
34 #define HAVE_SECONDARY_RELOADS
37 /* If MEMORY_MOVE_COST isn't defined, give it a default here. */
38 #ifndef MEMORY_MOVE_COST
39 #ifdef HAVE_SECONDARY_RELOADS
40 #define MEMORY_MOVE_COST(MODE,CLASS,IN) \
41 (4 + memory_move_secondary_cost ((MODE), (CLASS), (IN)))
43 #define MEMORY_MOVE_COST(MODE,CLASS,IN) 4
46 extern int memory_move_secondary_cost PROTO ((enum machine_mode, enum reg_class, int));
48 /* See reload.c and reload1.c for comments on these variables. */
50 /* Maximum number of reloads we can need. */
51 #define MAX_RELOADS (2 * MAX_RECOG_OPERANDS * (MAX_REGS_PER_ADDRESS + 1))
53 extern enum reg_class reload_address_base_reg_class;
54 extern enum reg_class reload_address_index_reg_class;
55 extern rtx reload_in[MAX_RELOADS];
56 extern rtx reload_out[MAX_RELOADS];
57 extern rtx reload_in_reg[MAX_RELOADS];
58 extern rtx reload_out_reg[MAX_RELOADS];
59 extern enum reg_class reload_reg_class[MAX_RELOADS];
60 extern enum machine_mode reload_inmode[MAX_RELOADS];
61 extern enum machine_mode reload_outmode[MAX_RELOADS];
62 extern char reload_optional[MAX_RELOADS];
63 extern char reload_nongroup[MAX_RELOADS];
64 extern int reload_inc[MAX_RELOADS];
65 extern int reload_opnum[MAX_RELOADS];
66 extern int reload_secondary_p[MAX_RELOADS];
67 extern int reload_secondary_in_reload[MAX_RELOADS];
68 extern int reload_secondary_out_reload[MAX_RELOADS];
70 extern enum insn_code reload_secondary_in_icode[MAX_RELOADS];
71 extern enum insn_code reload_secondary_out_icode[MAX_RELOADS];
75 extern rtx reload_reg_rtx[MAX_RELOADS];
77 /* Encode the usage of a reload. The following codes are supported:
79 RELOAD_FOR_INPUT reload of an input operand
80 RELOAD_FOR_OUTPUT likewise, for output
81 RELOAD_FOR_INSN a reload that must not conflict with anything
82 used in the insn, but may conflict with
83 something used before or after the insn
84 RELOAD_FOR_INPUT_ADDRESS reload for parts of the address of an object
85 that is an input reload
86 RELOAD_FOR_INPADDR_ADDRESS reload needed for RELOAD_FOR_INPUT_ADDRESS
87 RELOAD_FOR_OUTPUT_ADDRESS like RELOAD_FOR INPUT_ADDRESS, for output
88 RELOAD_FOR_OUTADDR_ADDRESS reload needed for RELOAD_FOR_OUTPUT_ADDRESS
89 RELOAD_FOR_OPERAND_ADDRESS reload for the address of a non-reloaded
90 operand; these don't conflict with
92 RELOAD_FOR_OPADDR_ADDR reload needed for RELOAD_FOR_OPERAND_ADDRESS
93 reloads; usually secondary reloads
94 RELOAD_OTHER none of the above, usually multiple uses
95 RELOAD_FOR_OTHER_ADDRESS reload for part of the address of an input
96 that is marked RELOAD_OTHER.
98 This used to be "enum reload_when_needed" but some debuggers have trouble
99 with an enum tag and variable of the same name. */
103 RELOAD_FOR_INPUT, RELOAD_FOR_OUTPUT, RELOAD_FOR_INSN,
104 RELOAD_FOR_INPUT_ADDRESS, RELOAD_FOR_INPADDR_ADDRESS,
105 RELOAD_FOR_OUTPUT_ADDRESS, RELOAD_FOR_OUTADDR_ADDRESS,
106 RELOAD_FOR_OPERAND_ADDRESS, RELOAD_FOR_OPADDR_ADDR,
107 RELOAD_OTHER, RELOAD_FOR_OTHER_ADDRESS
110 extern enum reload_type reload_when_needed[MAX_RELOADS];
112 extern rtx *reg_equiv_constant;
113 extern rtx *reg_equiv_memory_loc;
114 extern rtx *reg_equiv_address;
115 extern rtx *reg_equiv_mem;
117 /* All the "earlyclobber" operands of the current insn
118 are recorded here. */
119 extern int n_earlyclobbers;
120 extern rtx reload_earlyclobbers[MAX_RECOG_OPERANDS];
122 /* Save the number of operands. */
123 extern int reload_n_operands;
125 /* First uid used by insns created by reload in this function.
126 Used in find_equiv_reg. */
127 extern int reload_first_uid;
129 /* Nonzero if indirect addressing is supported when the innermost MEM is
130 of the form (MEM (SYMBOL_REF sym)). It is assumed that the level to
131 which these are valid is the same as spill_indirect_levels, above. */
133 extern char indirect_symref_ok;
135 /* Nonzero if an address (plus (reg frame_pointer) (reg ...)) is valid. */
136 extern char double_reg_address_ok;
138 extern int num_not_at_initial_offset;
141 /* These arrays record the insn_code of insns that may be needed to
142 perform input and output reloads of special objects. They provide a
143 place to pass a scratch register. */
144 extern enum insn_code reload_in_optab[];
145 extern enum insn_code reload_out_optab[];
150 /* [0] is normal, [1] is nongroup. */
151 short regs[2][N_REG_CLASSES];
152 short groups[N_REG_CLASSES];
155 #if defined SET_HARD_REG_BIT && defined CLEAR_REG_SET
156 /* This structure describes instructions which are relevant for reload.
157 Apart from all regular insns, this also includes CODE_LABELs, since they
158 must be examined for register elimination. */
161 /* Links to the neighbour instructions. */
162 struct insn_chain *next, *prev;
164 /* Link through a chains set up by calculate_needs_all_insns, containing
165 all insns that need reloading. */
166 struct insn_chain *next_need_reload;
168 /* The basic block this insn is in. */
170 /* The rtx of the insn. */
172 /* Register life information: record all live hard registers, and all
173 live pseudos that have a hard register.
174 This information is recorded for the point immediately before the insn
175 (in live_before), and for the point within the insn at which all
176 outputs have just been written to (in live_after). */
180 /* For each class, size of group of consecutive regs
181 that is needed for the reloads of this class. */
182 char group_size[N_REG_CLASSES];
183 /* For each class, the machine mode which requires consecutive
184 groups of regs of that class.
185 If two different modes ever require groups of one class,
186 they must be the same size and equally restrictive for that class,
187 otherwise we can't handle the complexity. */
188 enum machine_mode group_mode[N_REG_CLASSES];
190 /* Indicates if a register was counted against the need for
191 groups. 0 means it can count against max_nongroup instead. */
192 HARD_REG_SET counted_for_groups;
194 /* Indicates if a register was counted against the need for
195 non-groups. 0 means it can become part of a new group.
196 During choose_reload_regs, 1 here means don't use this reg
197 as part of a group, even if it seems to be otherwise ok. */
198 HARD_REG_SET counted_for_nongroups;
200 /* Indicates which registers have already been used for spills. */
201 HARD_REG_SET used_spill_regs;
203 /* Describe the needs for reload registers of this insn. */
206 /* Nonzero if find_reloads said the insn requires reloading. */
207 unsigned int need_reload:1;
208 /* Nonzero if eliminate_regs_in_insn said it requires eliminations. */
209 unsigned int need_elim:1;
210 /* Nonzero if this insn was inserted by perform_caller_saves. */
211 unsigned int is_caller_save_insn:1;
214 /* A chain of insn_chain structures to describe all non-note insns in
216 extern struct insn_chain *reload_insn_chain;
218 /* Allocate a new insn_chain structure. */
219 extern struct insn_chain *new_insn_chain PROTO((void));
221 extern void compute_use_by_pseudos PROTO((HARD_REG_SET *, regset));
224 /* Functions from reload.c: */
226 /* Return a memory location that will be used to copy X in mode MODE.
227 If we haven't already made a location for this mode in this insn,
228 call find_reloads_address on the location being returned. */
229 extern rtx get_secondary_mem PROTO((rtx, enum machine_mode,
230 int, enum reload_type));
232 /* Clear any secondary memory locations we've made. */
233 extern void clear_secondary_mem PROTO((void));
235 /* Transfer all replacements that used to be in reload FROM to be in
237 extern void transfer_replacements PROTO((int, int));
239 /* IN_RTX is the value loaded by a reload that we now decided to inherit,
240 or a subpart of it. If we have any replacements registered for IN_RTX,
241 chancel the reloads that were supposed to load them.
242 Return non-zero if we chanceled any reloads. */
243 extern int remove_address_replacements PROTO((rtx in_rtx));
245 /* Like rtx_equal_p except that it allows a REG and a SUBREG to match
246 if they are the same hard reg, and has special hacks for
247 autoincrement and autodecrement. */
248 extern int operands_match_p PROTO((rtx, rtx));
250 /* Return the number of times character C occurs in string S. */
251 extern int n_occurrences PROTO((int, char *));
253 /* Return 1 if altering OP will not modify the value of CLOBBER. */
254 extern int safe_from_earlyclobber PROTO((rtx, rtx));
256 /* Search the body of INSN for values that need reloading and record them
257 with push_reload. REPLACE nonzero means record also where the values occur
258 so that subst_reloads can be used. */
259 extern int find_reloads PROTO((rtx, int, int, int, short *));
261 /* Compute the sum of X and Y, making canonicalizations assumed in an
262 address, namely: sum constant integers, surround the sum of two
263 constants with a CONST, put the constant as the second operand, and
264 group the constant on the outermost sum. */
265 extern rtx form_sum PROTO((rtx, rtx));
267 /* Substitute into the current INSN the registers into which we have reloaded
268 the things that need reloading. */
269 extern void subst_reloads PROTO((void));
271 /* Make a copy of any replacements being done into X and move those copies
272 to locations in Y, a copy of X. We only look at the highest level of
274 extern void copy_replacements PROTO((rtx, rtx));
276 /* Change any replacements being done to *X to be done to *Y */
277 extern void move_replacements PROTO((rtx *x, rtx *y));
279 /* If LOC was scheduled to be replaced by something, return the replacement.
280 Otherwise, return *LOC. */
281 extern rtx find_replacement PROTO((rtx *));
283 /* Return nonzero if register in range [REGNO, ENDREGNO)
284 appears either explicitly or implicitly in X
285 other than being stored into. */
286 extern int refers_to_regno_for_reload_p PROTO((int, int, rtx, rtx *));
288 /* Nonzero if modifying X will affect IN. */
289 extern int reg_overlap_mentioned_for_reload_p PROTO((rtx, rtx));
291 /* Return nonzero if anything in X contains a MEM. Look also for pseudo
293 extern int refers_to_mem_for_reload_p PROTO((rtx));
295 /* Check the insns before INSN to see if there is a suitable register
296 containing the same value as GOAL. */
297 extern rtx find_equiv_reg PROTO((rtx, rtx, enum reg_class, int, short *,
298 int, enum machine_mode));
300 /* Return 1 if register REGNO is the subject of a clobber in insn INSN. */
301 extern int regno_clobbered_p PROTO((int, rtx));
303 /* Functions in reload1.c: */
305 extern int reloads_conflict PROTO ((int, int));
307 int count_occurrences PROTO((rtx, rtx));
309 /* Initialize the reload pass once per compilation. */
310 extern void init_reload PROTO((void));
312 /* The reload pass itself. */
313 extern int reload PROTO((rtx, int, FILE *));
315 /* Mark the slots in regs_ever_live for the hard regs
316 used by pseudo-reg number REGNO. */
317 extern void mark_home_live PROTO((int));
319 /* Scan X and replace any eliminable registers (such as fp) with a
320 replacement (such as sp), plus an offset. */
321 extern rtx eliminate_regs PROTO((rtx, enum machine_mode, rtx));
323 /* Emit code to perform a reload from IN (which may be a reload register) to
324 OUT (which may also be a reload register). IN or OUT is from operand
325 OPNUM with reload type TYPE. */
326 extern rtx gen_reload PROTO((rtx, rtx, int, enum reload_type));
328 /* Deallocate the reload register used by reload number R. */
329 extern void deallocate_reload_reg PROTO((int r));
331 /* Functions in caller-save.c: */
333 /* Initialize for caller-save. */
334 extern void init_caller_save PROTO((void));
336 /* Initialize save areas by showing that we haven't allocated any yet. */
337 extern void init_save_areas PROTO((void));
339 /* Allocate save areas for any hard registers that might need saving. */
340 extern void setup_save_areas PROTO((void));
342 /* Find the places where hard regs are live across calls and save them. */
343 extern void save_call_clobbered_regs PROTO((void));