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2bbd3819 | 1 | /* Allocate registers within a basic block, for GNU compiler. |
2e1253f3 | 2 | Copyright (C) 1987, 88, 91, 93-6, 1997 Free Software Foundation, Inc. |
2bbd3819 RS |
3 | |
4 | This file is part of GNU CC. | |
5 | ||
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) | |
9 | any later version. | |
10 | ||
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. | |
15 | ||
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 | |
a35311b0 RK |
18 | the Free Software Foundation, 59 Temple Place - Suite 330, |
19 | Boston, MA 02111-1307, USA. */ | |
2bbd3819 RS |
20 | |
21 | ||
22 | /* Allocation of hard register numbers to pseudo registers is done in | |
23 | two passes. In this pass we consider only regs that are born and | |
24 | die once within one basic block. We do this one basic block at a | |
25 | time. Then the next pass allocates the registers that remain. | |
26 | Two passes are used because this pass uses methods that work only | |
27 | on linear code, but that do a better job than the general methods | |
28 | used in global_alloc, and more quickly too. | |
29 | ||
30 | The assignments made are recorded in the vector reg_renumber | |
31 | whose space is allocated here. The rtl code itself is not altered. | |
32 | ||
33 | We assign each instruction in the basic block a number | |
34 | which is its order from the beginning of the block. | |
35 | Then we can represent the lifetime of a pseudo register with | |
36 | a pair of numbers, and check for conflicts easily. | |
37 | We can record the availability of hard registers with a | |
38 | HARD_REG_SET for each instruction. The HARD_REG_SET | |
39 | contains 0 or 1 for each hard reg. | |
40 | ||
41 | To avoid register shuffling, we tie registers together when one | |
42 | dies by being copied into another, or dies in an instruction that | |
43 | does arithmetic to produce another. The tied registers are | |
44 | allocated as one. Registers with different reg class preferences | |
45 | can never be tied unless the class preferred by one is a subclass | |
46 | of the one preferred by the other. | |
47 | ||
48 | Tying is represented with "quantity numbers". | |
49 | A non-tied register is given a new quantity number. | |
50 | Tied registers have the same quantity number. | |
51 | ||
52 | We have provision to exempt registers, even when they are contained | |
53 | within the block, that can be tied to others that are not contained in it. | |
54 | This is so that global_alloc could process them both and tie them then. | |
55 | But this is currently disabled since tying in global_alloc is not | |
56 | yet implemented. */ | |
57 | ||
6cad67d2 JL |
58 | /* Pseudos allocated here cannot be reallocated by global.c if the hard |
59 | register is used as a spill register. So we don't allocate such pseudos | |
60 | here if their preferred class is likely to be used by spills. */ | |
61 | ||
2bbd3819 | 62 | #include "config.h" |
e9a25f70 | 63 | #include <stdio.h> |
2bbd3819 RS |
64 | #include "rtl.h" |
65 | #include "flags.h" | |
66 | #include "basic-block.h" | |
67 | #include "regs.h" | |
68 | #include "hard-reg-set.h" | |
69 | #include "insn-config.h" | |
70 | #include "recog.h" | |
71 | #include "output.h" | |
72 | \f | |
73 | /* Next quantity number available for allocation. */ | |
74 | ||
75 | static int next_qty; | |
76 | ||
77 | /* In all the following vectors indexed by quantity number. */ | |
78 | ||
79 | /* Element Q is the hard reg number chosen for quantity Q, | |
80 | or -1 if none was found. */ | |
81 | ||
82 | static short *qty_phys_reg; | |
83 | ||
84 | /* We maintain two hard register sets that indicate suggested hard registers | |
85 | for each quantity. The first, qty_phys_copy_sugg, contains hard registers | |
86 | that are tied to the quantity by a simple copy. The second contains all | |
87 | hard registers that are tied to the quantity via an arithmetic operation. | |
88 | ||
89 | The former register set is given priority for allocation. This tends to | |
90 | eliminate copy insns. */ | |
91 | ||
92 | /* Element Q is a set of hard registers that are suggested for quantity Q by | |
93 | copy insns. */ | |
94 | ||
95 | static HARD_REG_SET *qty_phys_copy_sugg; | |
96 | ||
97 | /* Element Q is a set of hard registers that are suggested for quantity Q by | |
98 | arithmetic insns. */ | |
99 | ||
100 | static HARD_REG_SET *qty_phys_sugg; | |
101 | ||
51b86d8b | 102 | /* Element Q is the number of suggested registers in qty_phys_copy_sugg. */ |
2bbd3819 | 103 | |
51b86d8b | 104 | static short *qty_phys_num_copy_sugg; |
2bbd3819 | 105 | |
0f41302f | 106 | /* Element Q is the number of suggested registers in qty_phys_sugg. */ |
2bbd3819 | 107 | |
51b86d8b | 108 | static short *qty_phys_num_sugg; |
2bbd3819 RS |
109 | |
110 | /* Element Q is the number of refs to quantity Q. */ | |
111 | ||
aabf56ce | 112 | static int *qty_n_refs; |
2bbd3819 RS |
113 | |
114 | /* Element Q is a reg class contained in (smaller than) the | |
115 | preferred classes of all the pseudo regs that are tied in quantity Q. | |
116 | This is the preferred class for allocating that quantity. */ | |
117 | ||
118 | static enum reg_class *qty_min_class; | |
119 | ||
120 | /* Insn number (counting from head of basic block) | |
121 | where quantity Q was born. -1 if birth has not been recorded. */ | |
122 | ||
123 | static int *qty_birth; | |
124 | ||
125 | /* Insn number (counting from head of basic block) | |
126 | where quantity Q died. Due to the way tying is done, | |
127 | and the fact that we consider in this pass only regs that die but once, | |
128 | a quantity can die only once. Each quantity's life span | |
129 | is a set of consecutive insns. -1 if death has not been recorded. */ | |
130 | ||
131 | static int *qty_death; | |
132 | ||
133 | /* Number of words needed to hold the data in quantity Q. | |
134 | This depends on its machine mode. It is used for these purposes: | |
135 | 1. It is used in computing the relative importances of qtys, | |
136 | which determines the order in which we look for regs for them. | |
137 | 2. It is used in rules that prevent tying several registers of | |
138 | different sizes in a way that is geometrically impossible | |
139 | (see combine_regs). */ | |
140 | ||
141 | static int *qty_size; | |
142 | ||
143 | /* This holds the mode of the registers that are tied to qty Q, | |
144 | or VOIDmode if registers with differing modes are tied together. */ | |
145 | ||
146 | static enum machine_mode *qty_mode; | |
147 | ||
148 | /* Number of times a reg tied to qty Q lives across a CALL_INSN. */ | |
149 | ||
150 | static int *qty_n_calls_crossed; | |
151 | ||
e4600702 RK |
152 | /* Register class within which we allocate qty Q if we can't get |
153 | its preferred class. */ | |
2bbd3819 | 154 | |
e4600702 | 155 | static enum reg_class *qty_alternate_class; |
2bbd3819 RS |
156 | |
157 | /* Element Q is the SCRATCH expression for which this quantity is being | |
158 | allocated or 0 if this quantity is allocating registers. */ | |
159 | ||
160 | static rtx *qty_scratch_rtx; | |
161 | ||
0f64b8f6 RK |
162 | /* Element Q is nonzero if this quantity has been used in a SUBREG |
163 | that changes its size. */ | |
164 | ||
165 | static char *qty_changes_size; | |
166 | ||
2bbd3819 RS |
167 | /* Element Q is the register number of one pseudo register whose |
168 | reg_qty value is Q, or -1 is this quantity is for a SCRATCH. This | |
169 | register should be the head of the chain maintained in reg_next_in_qty. */ | |
170 | ||
aabf56ce | 171 | static int *qty_first_reg; |
2bbd3819 RS |
172 | |
173 | /* If (REG N) has been assigned a quantity number, is a register number | |
174 | of another register assigned the same quantity number, or -1 for the | |
175 | end of the chain. qty_first_reg point to the head of this chain. */ | |
176 | ||
aabf56ce | 177 | static int *reg_next_in_qty; |
2bbd3819 RS |
178 | |
179 | /* reg_qty[N] (where N is a pseudo reg number) is the qty number of that reg | |
180 | if it is >= 0, | |
181 | of -1 if this register cannot be allocated by local-alloc, | |
182 | or -2 if not known yet. | |
183 | ||
184 | Note that if we see a use or death of pseudo register N with | |
185 | reg_qty[N] == -2, register N must be local to the current block. If | |
186 | it were used in more than one block, we would have reg_qty[N] == -1. | |
187 | This relies on the fact that if reg_basic_block[N] is >= 0, register N | |
188 | will not appear in any other block. We save a considerable number of | |
189 | tests by exploiting this. | |
190 | ||
191 | If N is < FIRST_PSEUDO_REGISTER, reg_qty[N] is undefined and should not | |
192 | be referenced. */ | |
193 | ||
194 | static int *reg_qty; | |
195 | ||
196 | /* The offset (in words) of register N within its quantity. | |
197 | This can be nonzero if register N is SImode, and has been tied | |
198 | to a subreg of a DImode register. */ | |
199 | ||
200 | static char *reg_offset; | |
201 | ||
202 | /* Vector of substitutions of register numbers, | |
203 | used to map pseudo regs into hardware regs. | |
204 | This is set up as a result of register allocation. | |
205 | Element N is the hard reg assigned to pseudo reg N, | |
206 | or is -1 if no hard reg was assigned. | |
207 | If N is a hard reg number, element N is N. */ | |
208 | ||
209 | short *reg_renumber; | |
210 | ||
211 | /* Set of hard registers live at the current point in the scan | |
212 | of the instructions in a basic block. */ | |
213 | ||
214 | static HARD_REG_SET regs_live; | |
215 | ||
216 | /* Each set of hard registers indicates registers live at a particular | |
217 | point in the basic block. For N even, regs_live_at[N] says which | |
218 | hard registers are needed *after* insn N/2 (i.e., they may not | |
219 | conflict with the outputs of insn N/2 or the inputs of insn N/2 + 1. | |
220 | ||
221 | If an object is to conflict with the inputs of insn J but not the | |
222 | outputs of insn J + 1, we say it is born at index J*2 - 1. Similarly, | |
223 | if it is to conflict with the outputs of insn J but not the inputs of | |
224 | insn J + 1, it is said to die at index J*2 + 1. */ | |
225 | ||
226 | static HARD_REG_SET *regs_live_at; | |
227 | ||
bd5f197a RK |
228 | int *scratch_block; |
229 | rtx *scratch_list; | |
230 | int scratch_list_length; | |
231 | static int scratch_index; | |
232 | ||
2bbd3819 RS |
233 | /* Communicate local vars `insn_number' and `insn' |
234 | from `block_alloc' to `reg_is_set', `wipe_dead_reg', and `alloc_qty'. */ | |
235 | static int this_insn_number; | |
236 | static rtx this_insn; | |
237 | ||
c25a4c25 | 238 | /* Used to communicate changes made by update_equiv_regs to |
68342d36 RK |
239 | memref_referenced_p. reg_equiv_replacement is set for any REG_EQUIV note |
240 | found or created, so that we can keep track of what memory accesses might | |
241 | be created later, e.g. by reload. */ | |
242 | ||
c25a4c25 RK |
243 | static rtx *reg_equiv_replacement; |
244 | ||
82c68a78 RK |
245 | static void alloc_qty PROTO((int, enum machine_mode, int, int)); |
246 | static void alloc_qty_for_scratch PROTO((rtx, int, rtx, int, int)); | |
247 | static void validate_equiv_mem_from_store PROTO((rtx, rtx)); | |
248 | static int validate_equiv_mem PROTO((rtx, rtx, rtx)); | |
a1729519 | 249 | static int contains_replace_regs PROTO((rtx, char *)); |
82c68a78 RK |
250 | static int memref_referenced_p PROTO((rtx, rtx)); |
251 | static int memref_used_between_p PROTO((rtx, rtx, rtx)); | |
252 | static void optimize_reg_copy_1 PROTO((rtx, rtx, rtx)); | |
253 | static void optimize_reg_copy_2 PROTO((rtx, rtx, rtx)); | |
254 | static void update_equiv_regs PROTO((void)); | |
255 | static void block_alloc PROTO((int)); | |
51b86d8b | 256 | static int qty_sugg_compare PROTO((int, int)); |
2f23fcc9 | 257 | static int qty_sugg_compare_1 PROTO((const GENERIC_PTR, const GENERIC_PTR)); |
82c68a78 | 258 | static int qty_compare PROTO((int, int)); |
2f23fcc9 | 259 | static int qty_compare_1 PROTO((const GENERIC_PTR, const GENERIC_PTR)); |
82c68a78 RK |
260 | static int combine_regs PROTO((rtx, rtx, int, int, rtx, int)); |
261 | static int reg_meets_class_p PROTO((int, enum reg_class)); | |
262 | static int reg_classes_overlap_p PROTO((enum reg_class, enum reg_class, | |
263 | int)); | |
264 | static void update_qty_class PROTO((int, int)); | |
265 | static void reg_is_set PROTO((rtx, rtx)); | |
266 | static void reg_is_born PROTO((rtx, int)); | |
267 | static void wipe_dead_reg PROTO((rtx, int)); | |
268 | static int find_free_reg PROTO((enum reg_class, enum machine_mode, | |
269 | int, int, int, int, int)); | |
270 | static void mark_life PROTO((int, enum machine_mode, int)); | |
271 | static void post_mark_life PROTO((int, enum machine_mode, int, int, int)); | |
272 | static int no_conflict_p PROTO((rtx, rtx, rtx)); | |
3061cc54 | 273 | static int requires_inout PROTO((char *)); |
2bbd3819 RS |
274 | \f |
275 | /* Allocate a new quantity (new within current basic block) | |
276 | for register number REGNO which is born at index BIRTH | |
277 | within the block. MODE and SIZE are info on reg REGNO. */ | |
278 | ||
279 | static void | |
280 | alloc_qty (regno, mode, size, birth) | |
281 | int regno; | |
282 | enum machine_mode mode; | |
283 | int size, birth; | |
284 | { | |
285 | register int qty = next_qty++; | |
286 | ||
287 | reg_qty[regno] = qty; | |
288 | reg_offset[regno] = 0; | |
289 | reg_next_in_qty[regno] = -1; | |
290 | ||
291 | qty_first_reg[qty] = regno; | |
292 | qty_size[qty] = size; | |
293 | qty_mode[qty] = mode; | |
294 | qty_birth[qty] = birth; | |
b1f21e0a | 295 | qty_n_calls_crossed[qty] = REG_N_CALLS_CROSSED (regno); |
2bbd3819 | 296 | qty_min_class[qty] = reg_preferred_class (regno); |
e4600702 | 297 | qty_alternate_class[qty] = reg_alternate_class (regno); |
b1f21e0a MM |
298 | qty_n_refs[qty] = REG_N_REFS (regno); |
299 | qty_changes_size[qty] = REG_CHANGES_SIZE (regno); | |
2bbd3819 RS |
300 | } |
301 | \f | |
302 | /* Similar to `alloc_qty', but allocates a quantity for a SCRATCH rtx | |
303 | used as operand N in INSN. We assume here that the SCRATCH is used in | |
304 | a CLOBBER. */ | |
305 | ||
306 | static void | |
307 | alloc_qty_for_scratch (scratch, n, insn, insn_code_num, insn_number) | |
308 | rtx scratch; | |
309 | int n; | |
310 | rtx insn; | |
311 | int insn_code_num, insn_number; | |
312 | { | |
313 | register int qty; | |
314 | enum reg_class class; | |
315 | char *p, c; | |
316 | int i; | |
317 | ||
7fe4336e | 318 | #ifdef REGISTER_CONSTRAINTS |
2bbd3819 RS |
319 | /* If we haven't yet computed which alternative will be used, do so now. |
320 | Then set P to the constraints for that alternative. */ | |
321 | if (which_alternative == -1) | |
322 | if (! constrain_operands (insn_code_num, 0)) | |
323 | return; | |
324 | ||
325 | for (p = insn_operand_constraint[insn_code_num][n], i = 0; | |
326 | *p && i < which_alternative; p++) | |
327 | if (*p == ',') | |
328 | i++; | |
329 | ||
330 | /* Compute the class required for this SCRATCH. If we don't need a | |
331 | register, the class will remain NO_REGS. If we guessed the alternative | |
332 | number incorrectly, reload will fix things up for us. */ | |
333 | ||
334 | class = NO_REGS; | |
335 | while ((c = *p++) != '\0' && c != ',') | |
336 | switch (c) | |
337 | { | |
338 | case '=': case '+': case '?': | |
339 | case '#': case '&': case '!': | |
340 | case '*': case '%': | |
341 | case '0': case '1': case '2': case '3': case '4': | |
342 | case 'm': case '<': case '>': case 'V': case 'o': | |
343 | case 'E': case 'F': case 'G': case 'H': | |
344 | case 's': case 'i': case 'n': | |
345 | case 'I': case 'J': case 'K': case 'L': | |
346 | case 'M': case 'N': case 'O': case 'P': | |
347 | #ifdef EXTRA_CONSTRAINT | |
348 | case 'Q': case 'R': case 'S': case 'T': case 'U': | |
349 | #endif | |
350 | case 'p': | |
351 | /* These don't say anything we care about. */ | |
352 | break; | |
353 | ||
354 | case 'X': | |
355 | /* We don't need to allocate this SCRATCH. */ | |
356 | return; | |
357 | ||
358 | case 'g': case 'r': | |
359 | class = reg_class_subunion[(int) class][(int) GENERAL_REGS]; | |
360 | break; | |
361 | ||
362 | default: | |
363 | class | |
364 | = reg_class_subunion[(int) class][(int) REG_CLASS_FROM_LETTER (c)]; | |
365 | break; | |
366 | } | |
367 | ||
e15eb3aa | 368 | if (class == NO_REGS) |
2bbd3819 RS |
369 | return; |
370 | ||
7fe4336e RK |
371 | #else /* REGISTER_CONSTRAINTS */ |
372 | ||
373 | class = GENERAL_REGS; | |
374 | #endif | |
375 | ||
376 | ||
2bbd3819 RS |
377 | qty = next_qty++; |
378 | ||
379 | qty_first_reg[qty] = -1; | |
380 | qty_scratch_rtx[qty] = scratch; | |
381 | qty_size[qty] = GET_MODE_SIZE (GET_MODE (scratch)); | |
382 | qty_mode[qty] = GET_MODE (scratch); | |
383 | qty_birth[qty] = 2 * insn_number - 1; | |
384 | qty_death[qty] = 2 * insn_number + 1; | |
385 | qty_n_calls_crossed[qty] = 0; | |
386 | qty_min_class[qty] = class; | |
e4600702 | 387 | qty_alternate_class[qty] = NO_REGS; |
2bbd3819 | 388 | qty_n_refs[qty] = 1; |
0f64b8f6 | 389 | qty_changes_size[qty] = 0; |
2bbd3819 RS |
390 | } |
391 | \f | |
392 | /* Main entry point of this file. */ | |
393 | ||
394 | void | |
395 | local_alloc () | |
396 | { | |
397 | register int b, i; | |
398 | int max_qty; | |
399 | ||
400 | /* Leaf functions and non-leaf functions have different needs. | |
401 | If defined, let the machine say what kind of ordering we | |
402 | should use. */ | |
403 | #ifdef ORDER_REGS_FOR_LOCAL_ALLOC | |
404 | ORDER_REGS_FOR_LOCAL_ALLOC; | |
405 | #endif | |
406 | ||
407 | /* Promote REG_EQUAL notes to REG_EQUIV notes and adjust status of affected | |
408 | registers. */ | |
409 | update_equiv_regs (); | |
410 | ||
411 | /* This sets the maximum number of quantities we can have. Quantity | |
d45cf215 | 412 | numbers start at zero and we can have one for each pseudo plus the |
6dc42e49 | 413 | number of SCRATCHes in the largest block, in the worst case. */ |
2bbd3819 RS |
414 | max_qty = (max_regno - FIRST_PSEUDO_REGISTER) + max_scratch; |
415 | ||
416 | /* Allocate vectors of temporary data. | |
417 | See the declarations of these variables, above, | |
418 | for what they mean. */ | |
419 | ||
e15eb3aa RK |
420 | /* There can be up to MAX_SCRATCH * N_BASIC_BLOCKS SCRATCHes to allocate. |
421 | Instead of allocating this much memory from now until the end of | |
422 | reload, only allocate space for MAX_QTY SCRATCHes. If there are more | |
423 | reload will allocate them. */ | |
424 | ||
bd5f197a RK |
425 | scratch_list_length = max_qty; |
426 | scratch_list = (rtx *) xmalloc (scratch_list_length * sizeof (rtx)); | |
4c9a05bc | 427 | bzero ((char *) scratch_list, scratch_list_length * sizeof (rtx)); |
bd5f197a | 428 | scratch_block = (int *) xmalloc (scratch_list_length * sizeof (int)); |
4c9a05bc | 429 | bzero ((char *) scratch_block, scratch_list_length * sizeof (int)); |
bd5f197a RK |
430 | scratch_index = 0; |
431 | ||
2bbd3819 | 432 | qty_phys_reg = (short *) alloca (max_qty * sizeof (short)); |
4c9a05bc RK |
433 | qty_phys_copy_sugg |
434 | = (HARD_REG_SET *) alloca (max_qty * sizeof (HARD_REG_SET)); | |
fc0e5bd0 | 435 | qty_phys_num_copy_sugg = (short *) alloca (max_qty * sizeof (short)); |
2bbd3819 | 436 | qty_phys_sugg = (HARD_REG_SET *) alloca (max_qty * sizeof (HARD_REG_SET)); |
fc0e5bd0 | 437 | qty_phys_num_sugg = (short *) alloca (max_qty * sizeof (short)); |
2bbd3819 RS |
438 | qty_birth = (int *) alloca (max_qty * sizeof (int)); |
439 | qty_death = (int *) alloca (max_qty * sizeof (int)); | |
440 | qty_scratch_rtx = (rtx *) alloca (max_qty * sizeof (rtx)); | |
aabf56ce | 441 | qty_first_reg = (int *) alloca (max_qty * sizeof (int)); |
2bbd3819 | 442 | qty_size = (int *) alloca (max_qty * sizeof (int)); |
4c9a05bc RK |
443 | qty_mode |
444 | = (enum machine_mode *) alloca (max_qty * sizeof (enum machine_mode)); | |
2bbd3819 | 445 | qty_n_calls_crossed = (int *) alloca (max_qty * sizeof (int)); |
4c9a05bc RK |
446 | qty_min_class |
447 | = (enum reg_class *) alloca (max_qty * sizeof (enum reg_class)); | |
448 | qty_alternate_class | |
449 | = (enum reg_class *) alloca (max_qty * sizeof (enum reg_class)); | |
aabf56ce | 450 | qty_n_refs = (int *) alloca (max_qty * sizeof (int)); |
0f64b8f6 | 451 | qty_changes_size = (char *) alloca (max_qty * sizeof (char)); |
2bbd3819 RS |
452 | |
453 | reg_qty = (int *) alloca (max_regno * sizeof (int)); | |
454 | reg_offset = (char *) alloca (max_regno * sizeof (char)); | |
aabf56ce | 455 | reg_next_in_qty = (int *) alloca (max_regno * sizeof (int)); |
2bbd3819 | 456 | |
39379e67 MM |
457 | /* Allocate the reg_renumber array */ |
458 | allocate_reg_info (max_regno, FALSE, TRUE); | |
2bbd3819 RS |
459 | |
460 | /* Determine which pseudo-registers can be allocated by local-alloc. | |
461 | In general, these are the registers used only in a single block and | |
462 | which only die once. However, if a register's preferred class has only | |
cde62d1a | 463 | a few entries, don't allocate this register here unless it is preferred |
2bbd3819 RS |
464 | or nothing since retry_global_alloc won't be able to move it to |
465 | GENERAL_REGS if a reload register of this class is needed. | |
466 | ||
467 | We need not be concerned with which block actually uses the register | |
468 | since we will never see it outside that block. */ | |
469 | ||
470 | for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++) | |
471 | { | |
b1f21e0a | 472 | if (REG_BASIC_BLOCK (i) >= 0 && REG_N_DEATHS (i) == 1 |
e4600702 | 473 | && (reg_alternate_class (i) == NO_REGS |
cde62d1a | 474 | || ! CLASS_LIKELY_SPILLED_P (reg_preferred_class (i)))) |
2bbd3819 RS |
475 | reg_qty[i] = -2; |
476 | else | |
477 | reg_qty[i] = -1; | |
478 | } | |
479 | ||
480 | /* Force loop below to initialize entire quantity array. */ | |
481 | next_qty = max_qty; | |
482 | ||
483 | /* Allocate each block's local registers, block by block. */ | |
484 | ||
485 | for (b = 0; b < n_basic_blocks; b++) | |
486 | { | |
487 | /* NEXT_QTY indicates which elements of the `qty_...' | |
488 | vectors might need to be initialized because they were used | |
489 | for the previous block; it is set to the entire array before | |
490 | block 0. Initialize those, with explicit loop if there are few, | |
491 | else with bzero and bcopy. Do not initialize vectors that are | |
492 | explicit set by `alloc_qty'. */ | |
493 | ||
494 | if (next_qty < 6) | |
495 | { | |
496 | for (i = 0; i < next_qty; i++) | |
497 | { | |
498 | qty_scratch_rtx[i] = 0; | |
499 | CLEAR_HARD_REG_SET (qty_phys_copy_sugg[i]); | |
51b86d8b | 500 | qty_phys_num_copy_sugg[i] = 0; |
2bbd3819 | 501 | CLEAR_HARD_REG_SET (qty_phys_sugg[i]); |
51b86d8b | 502 | qty_phys_num_sugg[i] = 0; |
2bbd3819 RS |
503 | } |
504 | } | |
505 | else | |
506 | { | |
507 | #define CLEAR(vector) \ | |
4c9a05bc | 508 | bzero ((char *) (vector), (sizeof (*(vector))) * next_qty); |
2bbd3819 RS |
509 | |
510 | CLEAR (qty_scratch_rtx); | |
511 | CLEAR (qty_phys_copy_sugg); | |
51b86d8b | 512 | CLEAR (qty_phys_num_copy_sugg); |
2bbd3819 | 513 | CLEAR (qty_phys_sugg); |
51b86d8b | 514 | CLEAR (qty_phys_num_sugg); |
2bbd3819 RS |
515 | } |
516 | ||
517 | next_qty = 0; | |
518 | ||
519 | block_alloc (b); | |
520 | #ifdef USE_C_ALLOCA | |
521 | alloca (0); | |
522 | #endif | |
523 | } | |
524 | } | |
525 | \f | |
526 | /* Depth of loops we are in while in update_equiv_regs. */ | |
527 | static int loop_depth; | |
528 | ||
529 | /* Used for communication between the following two functions: contains | |
530 | a MEM that we wish to ensure remains unchanged. */ | |
531 | static rtx equiv_mem; | |
532 | ||
533 | /* Set nonzero if EQUIV_MEM is modified. */ | |
534 | static int equiv_mem_modified; | |
535 | ||
536 | /* If EQUIV_MEM is modified by modifying DEST, indicate that it is modified. | |
537 | Called via note_stores. */ | |
538 | ||
539 | static void | |
540 | validate_equiv_mem_from_store (dest, set) | |
541 | rtx dest; | |
542 | rtx set; | |
543 | { | |
544 | if ((GET_CODE (dest) == REG | |
545 | && reg_overlap_mentioned_p (dest, equiv_mem)) | |
546 | || (GET_CODE (dest) == MEM | |
9ae8ffe7 | 547 | && true_dependence (dest, VOIDmode, equiv_mem, rtx_varies_p))) |
2bbd3819 RS |
548 | equiv_mem_modified = 1; |
549 | } | |
550 | ||
551 | /* Verify that no store between START and the death of REG invalidates | |
552 | MEMREF. MEMREF is invalidated by modifying a register used in MEMREF, | |
553 | by storing into an overlapping memory location, or with a non-const | |
554 | CALL_INSN. | |
555 | ||
556 | Return 1 if MEMREF remains valid. */ | |
557 | ||
558 | static int | |
559 | validate_equiv_mem (start, reg, memref) | |
560 | rtx start; | |
561 | rtx reg; | |
562 | rtx memref; | |
563 | { | |
564 | rtx insn; | |
565 | rtx note; | |
566 | ||
567 | equiv_mem = memref; | |
568 | equiv_mem_modified = 0; | |
569 | ||
570 | /* If the memory reference has side effects or is volatile, it isn't a | |
571 | valid equivalence. */ | |
572 | if (side_effects_p (memref)) | |
573 | return 0; | |
574 | ||
575 | for (insn = start; insn && ! equiv_mem_modified; insn = NEXT_INSN (insn)) | |
576 | { | |
577 | if (GET_RTX_CLASS (GET_CODE (insn)) != 'i') | |
578 | continue; | |
579 | ||
580 | if (find_reg_note (insn, REG_DEAD, reg)) | |
581 | return 1; | |
582 | ||
583 | if (GET_CODE (insn) == CALL_INSN && ! RTX_UNCHANGING_P (memref) | |
584 | && ! CONST_CALL_P (insn)) | |
585 | return 0; | |
586 | ||
587 | note_stores (PATTERN (insn), validate_equiv_mem_from_store); | |
588 | ||
589 | /* If a register mentioned in MEMREF is modified via an | |
590 | auto-increment, we lose the equivalence. Do the same if one | |
591 | dies; although we could extend the life, it doesn't seem worth | |
592 | the trouble. */ | |
593 | ||
594 | for (note = REG_NOTES (insn); note; note = XEXP (note, 1)) | |
595 | if ((REG_NOTE_KIND (note) == REG_INC | |
596 | || REG_NOTE_KIND (note) == REG_DEAD) | |
597 | && GET_CODE (XEXP (note, 0)) == REG | |
598 | && reg_overlap_mentioned_p (XEXP (note, 0), memref)) | |
599 | return 0; | |
600 | } | |
601 | ||
602 | return 0; | |
603 | } | |
a1729519 JW |
604 | |
605 | /* TRUE if X uses any registers for which reg_equiv_replace is true. */ | |
606 | ||
607 | static int | |
608 | contains_replace_regs (x, reg_equiv_replace) | |
609 | rtx x; | |
610 | char *reg_equiv_replace; | |
611 | { | |
612 | int i, j; | |
613 | char *fmt; | |
614 | enum rtx_code code = GET_CODE (x); | |
615 | ||
616 | switch (code) | |
617 | { | |
618 | case CONST_INT: | |
619 | case CONST: | |
620 | case LABEL_REF: | |
621 | case SYMBOL_REF: | |
622 | case CONST_DOUBLE: | |
623 | case PC: | |
624 | case CC0: | |
625 | case HIGH: | |
626 | case LO_SUM: | |
627 | return 0; | |
628 | ||
629 | case REG: | |
630 | return reg_equiv_replace[REGNO (x)]; | |
631 | } | |
632 | ||
633 | fmt = GET_RTX_FORMAT (code); | |
634 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
635 | switch (fmt[i]) | |
636 | { | |
637 | case 'e': | |
638 | if (contains_replace_regs (XEXP (x, i), reg_equiv_replace)) | |
639 | return 1; | |
640 | break; | |
641 | case 'E': | |
642 | for (j = XVECLEN (x, i) - 1; j >= 0; j--) | |
643 | if (contains_replace_regs (XVECEXP (x, i, j), reg_equiv_replace)) | |
644 | return 1; | |
645 | break; | |
646 | } | |
647 | ||
648 | return 0; | |
649 | } | |
2bbd3819 RS |
650 | \f |
651 | /* TRUE if X references a memory location that would be affected by a store | |
652 | to MEMREF. */ | |
653 | ||
654 | static int | |
655 | memref_referenced_p (memref, x) | |
656 | rtx x; | |
657 | rtx memref; | |
658 | { | |
659 | int i, j; | |
660 | char *fmt; | |
661 | enum rtx_code code = GET_CODE (x); | |
662 | ||
663 | switch (code) | |
664 | { | |
2bbd3819 RS |
665 | case CONST_INT: |
666 | case CONST: | |
667 | case LABEL_REF: | |
668 | case SYMBOL_REF: | |
669 | case CONST_DOUBLE: | |
670 | case PC: | |
671 | case CC0: | |
672 | case HIGH: | |
673 | case LO_SUM: | |
674 | return 0; | |
675 | ||
c25a4c25 | 676 | case REG: |
3298a1b1 RK |
677 | return (reg_equiv_replacement[REGNO (x)] |
678 | && memref_referenced_p (memref, | |
c25a4c25 RK |
679 | reg_equiv_replacement[REGNO (x)])); |
680 | ||
2bbd3819 | 681 | case MEM: |
9ae8ffe7 | 682 | if (true_dependence (memref, VOIDmode, x, rtx_varies_p)) |
2bbd3819 RS |
683 | return 1; |
684 | break; | |
685 | ||
686 | case SET: | |
687 | /* If we are setting a MEM, it doesn't count (its address does), but any | |
688 | other SET_DEST that has a MEM in it is referencing the MEM. */ | |
689 | if (GET_CODE (SET_DEST (x)) == MEM) | |
690 | { | |
691 | if (memref_referenced_p (memref, XEXP (SET_DEST (x), 0))) | |
692 | return 1; | |
693 | } | |
694 | else if (memref_referenced_p (memref, SET_DEST (x))) | |
695 | return 1; | |
696 | ||
697 | return memref_referenced_p (memref, SET_SRC (x)); | |
e9a25f70 JL |
698 | |
699 | default: | |
700 | break; | |
2bbd3819 RS |
701 | } |
702 | ||
703 | fmt = GET_RTX_FORMAT (code); | |
704 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
705 | switch (fmt[i]) | |
706 | { | |
707 | case 'e': | |
708 | if (memref_referenced_p (memref, XEXP (x, i))) | |
709 | return 1; | |
710 | break; | |
711 | case 'E': | |
712 | for (j = XVECLEN (x, i) - 1; j >= 0; j--) | |
713 | if (memref_referenced_p (memref, XVECEXP (x, i, j))) | |
714 | return 1; | |
715 | break; | |
716 | } | |
717 | ||
718 | return 0; | |
719 | } | |
720 | ||
721 | /* TRUE if some insn in the range (START, END] references a memory location | |
722 | that would be affected by a store to MEMREF. */ | |
723 | ||
724 | static int | |
725 | memref_used_between_p (memref, start, end) | |
726 | rtx memref; | |
727 | rtx start; | |
728 | rtx end; | |
729 | { | |
730 | rtx insn; | |
731 | ||
732 | for (insn = NEXT_INSN (start); insn != NEXT_INSN (end); | |
733 | insn = NEXT_INSN (insn)) | |
734 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i' | |
735 | && memref_referenced_p (memref, PATTERN (insn))) | |
736 | return 1; | |
737 | ||
738 | return 0; | |
739 | } | |
740 | \f | |
741 | /* INSN is a copy from SRC to DEST, both registers, and SRC does not die | |
742 | in INSN. | |
743 | ||
744 | Search forward to see if SRC dies before either it or DEST is modified, | |
745 | but don't scan past the end of a basic block. If so, we can replace SRC | |
746 | with DEST and let SRC die in INSN. | |
747 | ||
748 | This will reduce the number of registers live in that range and may enable | |
749 | DEST to be tied to SRC, thus often saving one register in addition to a | |
750 | register-register copy. */ | |
751 | ||
752 | static void | |
d45cf215 | 753 | optimize_reg_copy_1 (insn, dest, src) |
2bbd3819 RS |
754 | rtx insn; |
755 | rtx dest; | |
756 | rtx src; | |
757 | { | |
758 | rtx p, q; | |
759 | rtx note; | |
760 | rtx dest_death = 0; | |
761 | int sregno = REGNO (src); | |
762 | int dregno = REGNO (dest); | |
763 | ||
e9a25f70 | 764 | /* We don't want to mess with hard regs if register classes are small. */ |
2bbd3819 | 765 | if (sregno == dregno |
f95182a4 ILT |
766 | || (SMALL_REGISTER_CLASSES |
767 | && (sregno < FIRST_PSEUDO_REGISTER | |
768 | || dregno < FIRST_PSEUDO_REGISTER)) | |
2bbd3819 RS |
769 | /* We don't see all updates to SP if they are in an auto-inc memory |
770 | reference, so we must disallow this optimization on them. */ | |
771 | || sregno == STACK_POINTER_REGNUM || dregno == STACK_POINTER_REGNUM) | |
772 | return; | |
773 | ||
774 | for (p = NEXT_INSN (insn); p; p = NEXT_INSN (p)) | |
775 | { | |
776 | if (GET_CODE (p) == CODE_LABEL || GET_CODE (p) == JUMP_INSN | |
777 | || (GET_CODE (p) == NOTE | |
778 | && (NOTE_LINE_NUMBER (p) == NOTE_INSN_LOOP_BEG | |
779 | || NOTE_LINE_NUMBER (p) == NOTE_INSN_LOOP_END))) | |
780 | break; | |
781 | ||
782 | if (GET_RTX_CLASS (GET_CODE (p)) != 'i') | |
783 | continue; | |
784 | ||
785 | if (reg_set_p (src, p) || reg_set_p (dest, p) | |
786 | /* Don't change a USE of a register. */ | |
787 | || (GET_CODE (PATTERN (p)) == USE | |
788 | && reg_overlap_mentioned_p (src, XEXP (PATTERN (p), 0)))) | |
789 | break; | |
790 | ||
d9983d6c | 791 | /* See if all of SRC dies in P. This test is slightly more |
0f41302f | 792 | conservative than it needs to be. */ |
d9983d6c RK |
793 | if ((note = find_regno_note (p, REG_DEAD, sregno)) != 0 |
794 | && GET_MODE (XEXP (note, 0)) == GET_MODE (src)) | |
2bbd3819 RS |
795 | { |
796 | int failed = 0; | |
797 | int length = 0; | |
d9983d6c | 798 | int d_length = 0; |
2bbd3819 | 799 | int n_calls = 0; |
d9983d6c | 800 | int d_n_calls = 0; |
2bbd3819 RS |
801 | |
802 | /* We can do the optimization. Scan forward from INSN again, | |
803 | replacing regs as we go. Set FAILED if a replacement can't | |
804 | be done. In that case, we can't move the death note for SRC. | |
805 | This should be rare. */ | |
806 | ||
807 | /* Set to stop at next insn. */ | |
808 | for (q = next_real_insn (insn); | |
809 | q != next_real_insn (p); | |
810 | q = next_real_insn (q)) | |
811 | { | |
d9983d6c | 812 | if (reg_overlap_mentioned_p (src, PATTERN (q))) |
2bbd3819 | 813 | { |
d9983d6c RK |
814 | /* If SRC is a hard register, we might miss some |
815 | overlapping registers with validate_replace_rtx, | |
816 | so we would have to undo it. We can't if DEST is | |
817 | present in the insn, so fail in that combination | |
818 | of cases. */ | |
819 | if (sregno < FIRST_PSEUDO_REGISTER | |
820 | && reg_mentioned_p (dest, PATTERN (q))) | |
821 | failed = 1; | |
822 | ||
823 | /* Replace all uses and make sure that the register | |
824 | isn't still present. */ | |
825 | else if (validate_replace_rtx (src, dest, q) | |
826 | && (sregno >= FIRST_PSEUDO_REGISTER | |
827 | || ! reg_overlap_mentioned_p (src, | |
828 | PATTERN (q)))) | |
2bbd3819 RS |
829 | { |
830 | /* We assume that a register is used exactly once per | |
831 | insn in the updates below. If this is not correct, | |
832 | no great harm is done. */ | |
833 | if (sregno >= FIRST_PSEUDO_REGISTER) | |
b1f21e0a | 834 | REG_N_REFS (sregno) -= loop_depth; |
2bbd3819 | 835 | if (dregno >= FIRST_PSEUDO_REGISTER) |
b1f21e0a | 836 | REG_N_REFS (dregno) += loop_depth; |
2bbd3819 RS |
837 | } |
838 | else | |
d9983d6c RK |
839 | { |
840 | validate_replace_rtx (dest, src, q); | |
841 | failed = 1; | |
842 | } | |
2bbd3819 RS |
843 | } |
844 | ||
845 | /* Count the insns and CALL_INSNs passed. If we passed the | |
846 | death note of DEST, show increased live length. */ | |
847 | length++; | |
848 | if (dest_death) | |
d9983d6c | 849 | d_length++; |
2bbd3819 | 850 | |
da2c9ff9 RK |
851 | /* If the insn in which SRC dies is a CALL_INSN, don't count it |
852 | as a call that has been crossed. Otherwise, count it. */ | |
853 | if (q != p && GET_CODE (q) == CALL_INSN) | |
2bbd3819 RS |
854 | { |
855 | n_calls++; | |
856 | if (dest_death) | |
d9983d6c | 857 | d_n_calls++; |
2bbd3819 RS |
858 | } |
859 | ||
860 | /* If DEST dies here, remove the death note and save it for | |
d9983d6c RK |
861 | later. Make sure ALL of DEST dies here; again, this is |
862 | overly conservative. */ | |
2bbd3819 | 863 | if (dest_death == 0 |
d9983d6c RK |
864 | && (dest_death = find_regno_note (q, REG_DEAD, dregno)) != 0 |
865 | && GET_MODE (XEXP (dest_death, 0)) == GET_MODE (dest)) | |
2bbd3819 RS |
866 | remove_note (q, dest_death); |
867 | } | |
868 | ||
869 | if (! failed) | |
870 | { | |
871 | if (sregno >= FIRST_PSEUDO_REGISTER) | |
872 | { | |
b1f21e0a | 873 | if (REG_LIVE_LENGTH (sregno) >= 0) |
c7b1ed2b | 874 | { |
b1f21e0a | 875 | REG_LIVE_LENGTH (sregno) -= length; |
c7b1ed2b RK |
876 | /* reg_live_length is only an approximation after |
877 | combine if sched is not run, so make sure that we | |
878 | still have a reasonable value. */ | |
b1f21e0a MM |
879 | if (REG_LIVE_LENGTH (sregno) < 2) |
880 | REG_LIVE_LENGTH (sregno) = 2; | |
c7b1ed2b RK |
881 | } |
882 | ||
b1f21e0a | 883 | REG_N_CALLS_CROSSED (sregno) -= n_calls; |
2bbd3819 RS |
884 | } |
885 | ||
d9983d6c RK |
886 | if (dregno >= FIRST_PSEUDO_REGISTER) |
887 | { | |
b1f21e0a MM |
888 | if (REG_LIVE_LENGTH (dregno) >= 0) |
889 | REG_LIVE_LENGTH (dregno) += d_length; | |
c7b1ed2b | 890 | |
b1f21e0a | 891 | REG_N_CALLS_CROSSED (dregno) += d_n_calls; |
d9983d6c RK |
892 | } |
893 | ||
2bbd3819 RS |
894 | /* Move death note of SRC from P to INSN. */ |
895 | remove_note (p, note); | |
896 | XEXP (note, 1) = REG_NOTES (insn); | |
897 | REG_NOTES (insn) = note; | |
898 | } | |
899 | ||
900 | /* Put death note of DEST on P if we saw it die. */ | |
901 | if (dest_death) | |
902 | { | |
903 | XEXP (dest_death, 1) = REG_NOTES (p); | |
904 | REG_NOTES (p) = dest_death; | |
905 | } | |
906 | ||
907 | return; | |
908 | } | |
d9983d6c RK |
909 | |
910 | /* If SRC is a hard register which is set or killed in some other | |
911 | way, we can't do this optimization. */ | |
912 | else if (sregno < FIRST_PSEUDO_REGISTER | |
913 | && dead_or_set_p (p, src)) | |
914 | break; | |
2bbd3819 RS |
915 | } |
916 | } | |
d45cf215 RS |
917 | \f |
918 | /* INSN is a copy of SRC to DEST, in which SRC dies. See if we now have | |
919 | a sequence of insns that modify DEST followed by an insn that sets | |
920 | SRC to DEST in which DEST dies, with no prior modification of DEST. | |
921 | (There is no need to check if the insns in between actually modify | |
922 | DEST. We should not have cases where DEST is not modified, but | |
923 | the optimization is safe if no such modification is detected.) | |
924 | In that case, we can replace all uses of DEST, starting with INSN and | |
925 | ending with the set of SRC to DEST, with SRC. We do not do this | |
926 | optimization if a CALL_INSN is crossed unless SRC already crosses a | |
058e0bb9 | 927 | call or if DEST dies before the copy back to SRC. |
d45cf215 RS |
928 | |
929 | It is assumed that DEST and SRC are pseudos; it is too complicated to do | |
930 | this for hard registers since the substitutions we may make might fail. */ | |
931 | ||
932 | static void | |
933 | optimize_reg_copy_2 (insn, dest, src) | |
934 | rtx insn; | |
935 | rtx dest; | |
936 | rtx src; | |
937 | { | |
938 | rtx p, q; | |
939 | rtx set; | |
940 | int sregno = REGNO (src); | |
941 | int dregno = REGNO (dest); | |
942 | ||
943 | for (p = NEXT_INSN (insn); p; p = NEXT_INSN (p)) | |
944 | { | |
945 | if (GET_CODE (p) == CODE_LABEL || GET_CODE (p) == JUMP_INSN | |
946 | || (GET_CODE (p) == NOTE | |
947 | && (NOTE_LINE_NUMBER (p) == NOTE_INSN_LOOP_BEG | |
948 | || NOTE_LINE_NUMBER (p) == NOTE_INSN_LOOP_END))) | |
949 | break; | |
950 | ||
951 | if (GET_RTX_CLASS (GET_CODE (p)) != 'i') | |
952 | continue; | |
953 | ||
954 | set = single_set (p); | |
955 | if (set && SET_SRC (set) == dest && SET_DEST (set) == src | |
956 | && find_reg_note (p, REG_DEAD, dest)) | |
957 | { | |
958 | /* We can do the optimization. Scan forward from INSN again, | |
959 | replacing regs as we go. */ | |
960 | ||
961 | /* Set to stop at next insn. */ | |
962 | for (q = insn; q != NEXT_INSN (p); q = NEXT_INSN (q)) | |
963 | if (GET_RTX_CLASS (GET_CODE (q)) == 'i') | |
964 | { | |
965 | if (reg_mentioned_p (dest, PATTERN (q))) | |
966 | { | |
967 | PATTERN (q) = replace_rtx (PATTERN (q), dest, src); | |
968 | ||
969 | /* We assume that a register is used exactly once per | |
970 | insn in the updates below. If this is not correct, | |
971 | no great harm is done. */ | |
b1f21e0a MM |
972 | REG_N_REFS (dregno) -= loop_depth; |
973 | REG_N_REFS (sregno) += loop_depth; | |
d45cf215 RS |
974 | } |
975 | ||
976 | ||
977 | if (GET_CODE (q) == CALL_INSN) | |
978 | { | |
b1f21e0a MM |
979 | REG_N_CALLS_CROSSED (dregno)--; |
980 | REG_N_CALLS_CROSSED (sregno)++; | |
d45cf215 RS |
981 | } |
982 | } | |
983 | ||
984 | remove_note (p, find_reg_note (p, REG_DEAD, dest)); | |
b1f21e0a | 985 | REG_N_DEATHS (dregno)--; |
d45cf215 | 986 | remove_note (insn, find_reg_note (insn, REG_DEAD, src)); |
b1f21e0a | 987 | REG_N_DEATHS (sregno)--; |
d45cf215 RS |
988 | return; |
989 | } | |
990 | ||
991 | if (reg_set_p (src, p) | |
058e0bb9 | 992 | || find_reg_note (p, REG_DEAD, dest) |
b1f21e0a | 993 | || (GET_CODE (p) == CALL_INSN && REG_N_CALLS_CROSSED (sregno) == 0)) |
d45cf215 RS |
994 | break; |
995 | } | |
996 | } | |
2bbd3819 RS |
997 | \f |
998 | /* Find registers that are equivalent to a single value throughout the | |
999 | compilation (either because they can be referenced in memory or are set once | |
1000 | from a single constant). Lower their priority for a register. | |
1001 | ||
1002 | If such a register is only referenced once, try substituting its value | |
1003 | into the using insn. If it succeeds, we can eliminate the register | |
1004 | completely. */ | |
1005 | ||
1006 | static void | |
1007 | update_equiv_regs () | |
1008 | { | |
1009 | rtx *reg_equiv_init_insn = (rtx *) alloca (max_regno * sizeof (rtx *)); | |
68342d36 RK |
1010 | /* Set when an attempt should be made to replace a register with the |
1011 | associated reg_equiv_replacement entry at the end of this function. */ | |
1012 | char *reg_equiv_replace | |
1013 | = (char *) alloca (max_regno * sizeof *reg_equiv_replace); | |
2bbd3819 | 1014 | rtx insn; |
2e1253f3 | 1015 | int block, depth; |
2bbd3819 | 1016 | |
c25a4c25 RK |
1017 | reg_equiv_replacement = (rtx *) alloca (max_regno * sizeof (rtx *)); |
1018 | ||
4c9a05bc RK |
1019 | bzero ((char *) reg_equiv_init_insn, max_regno * sizeof (rtx *)); |
1020 | bzero ((char *) reg_equiv_replacement, max_regno * sizeof (rtx *)); | |
68342d36 | 1021 | bzero ((char *) reg_equiv_replace, max_regno * sizeof *reg_equiv_replace); |
2bbd3819 RS |
1022 | |
1023 | init_alias_analysis (); | |
1024 | ||
1025 | loop_depth = 1; | |
1026 | ||
1027 | /* Scan the insns and find which registers have equivalences. Do this | |
1028 | in a separate scan of the insns because (due to -fcse-follow-jumps) | |
1029 | a register can be set below its use. */ | |
1030 | for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) | |
1031 | { | |
1032 | rtx note; | |
1033 | rtx set = single_set (insn); | |
49ddab16 | 1034 | rtx dest, src; |
2bbd3819 RS |
1035 | int regno; |
1036 | ||
1037 | if (GET_CODE (insn) == NOTE) | |
1038 | { | |
1039 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG) | |
1040 | loop_depth++; | |
1041 | else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END) | |
1042 | loop_depth--; | |
1043 | } | |
1044 | ||
1045 | /* If this insn contains more (or less) than a single SET, ignore it. */ | |
1046 | if (set == 0) | |
1047 | continue; | |
1048 | ||
1049 | dest = SET_DEST (set); | |
49ddab16 | 1050 | src = SET_SRC (set); |
2bbd3819 RS |
1051 | |
1052 | /* If this sets a MEM to the contents of a REG that is only used | |
1053 | in a single basic block, see if the register is always equivalent | |
1054 | to that memory location and if moving the store from INSN to the | |
1055 | insn that set REG is safe. If so, put a REG_EQUIV note on the | |
a1729519 JW |
1056 | initializing insn. |
1057 | ||
1058 | Don't add a REG_EQUIV note if the insn already has one. The existing | |
1059 | REG_EQUIV is likely more useful than the one we are adding. | |
1060 | ||
1061 | If one of the regs in the address is marked as reg_equiv_replace, | |
1062 | then we can't add this REG_EQUIV note. The reg_equiv_replace | |
1063 | optimization may move the set of this register immediately before | |
1064 | insn, which puts it after reg_equiv_init_insn[regno], and hence | |
1065 | the mention in the REG_EQUIV note would be to an uninitialized | |
1066 | pseudo. */ | |
2bbd3819 RS |
1067 | |
1068 | if (GET_CODE (dest) == MEM && GET_CODE (SET_SRC (set)) == REG | |
1069 | && (regno = REGNO (SET_SRC (set))) >= FIRST_PSEUDO_REGISTER | |
b1f21e0a | 1070 | && REG_BASIC_BLOCK (regno) >= 0 |
2bbd3819 | 1071 | && reg_equiv_init_insn[regno] != 0 |
a1729519 JW |
1072 | && ! find_reg_note (insn, REG_EQUIV, NULL_RTX) |
1073 | && ! contains_replace_regs (XEXP (dest, 0), reg_equiv_replace) | |
2bbd3819 RS |
1074 | && validate_equiv_mem (reg_equiv_init_insn[regno], SET_SRC (set), |
1075 | dest) | |
1076 | && ! memref_used_between_p (SET_DEST (set), | |
1077 | reg_equiv_init_insn[regno], insn)) | |
1078 | REG_NOTES (reg_equiv_init_insn[regno]) | |
1079 | = gen_rtx (EXPR_LIST, REG_EQUIV, dest, | |
1080 | REG_NOTES (reg_equiv_init_insn[regno])); | |
1081 | ||
1082 | /* If this is a register-register copy where SRC is not dead, see if we | |
1083 | can optimize it. */ | |
1084 | if (flag_expensive_optimizations && GET_CODE (dest) == REG | |
1085 | && GET_CODE (SET_SRC (set)) == REG | |
1086 | && ! find_reg_note (insn, REG_DEAD, SET_SRC (set))) | |
d45cf215 RS |
1087 | optimize_reg_copy_1 (insn, dest, SET_SRC (set)); |
1088 | ||
1089 | /* Similarly for a pseudo-pseudo copy when SRC is dead. */ | |
1090 | else if (flag_expensive_optimizations && GET_CODE (dest) == REG | |
1091 | && REGNO (dest) >= FIRST_PSEUDO_REGISTER | |
1092 | && GET_CODE (SET_SRC (set)) == REG | |
1093 | && REGNO (SET_SRC (set)) >= FIRST_PSEUDO_REGISTER | |
1094 | && find_reg_note (insn, REG_DEAD, SET_SRC (set))) | |
1095 | optimize_reg_copy_2 (insn, dest, SET_SRC (set)); | |
2bbd3819 RS |
1096 | |
1097 | /* Otherwise, we only handle the case of a pseudo register being set | |
49ddab16 JL |
1098 | once and only if neither the source nor the destination are |
1099 | in a register class that's likely to be spilled. */ | |
2bbd3819 RS |
1100 | if (GET_CODE (dest) != REG |
1101 | || (regno = REGNO (dest)) < FIRST_PSEUDO_REGISTER | |
b1f21e0a | 1102 | || REG_N_SETS (regno) != 1 |
49ddab16 JL |
1103 | || CLASS_LIKELY_SPILLED_P (reg_preferred_class (REGNO (dest))) |
1104 | || (GET_CODE (src) == REG | |
1105 | && REGNO (src) >= FIRST_PSEUDO_REGISTER | |
1106 | && CLASS_LIKELY_SPILLED_P (reg_preferred_class (REGNO (src))))) | |
2bbd3819 RS |
1107 | continue; |
1108 | ||
b1ec3c92 | 1109 | note = find_reg_note (insn, REG_EQUAL, NULL_RTX); |
2bbd3819 | 1110 | |
39dfb55a JL |
1111 | #ifdef DONT_RECORD_EQUIVALENCE |
1112 | /* Allow the target to reject promotions of some REG_EQUAL notes to | |
1113 | REG_EQUIV notes. | |
1114 | ||
1115 | In some cases this can improve register allocation if the existence | |
1116 | of the REG_EQUIV note is likely to increase the lifetime of a register | |
1117 | that is likely to be spilled. | |
1118 | ||
1119 | It may also be necessary if the target can't handle certain constant | |
1120 | expressions appearing randomly in insns, but for whatever reason | |
1121 | those expressions must be considered legitimate constant expressions | |
1122 | to prevent them from being forced into memory. */ | |
1123 | if (note && DONT_RECORD_EQUIVALENCE (note)) | |
1124 | note = NULL; | |
1125 | #endif | |
1126 | ||
2bbd3819 RS |
1127 | /* Record this insn as initializing this register. */ |
1128 | reg_equiv_init_insn[regno] = insn; | |
1129 | ||
1130 | /* If this register is known to be equal to a constant, record that | |
1131 | it is always equivalent to the constant. */ | |
1132 | if (note && CONSTANT_P (XEXP (note, 0))) | |
1133 | PUT_MODE (note, (enum machine_mode) REG_EQUIV); | |
1134 | ||
1135 | /* If this insn introduces a "constant" register, decrease the priority | |
1136 | of that register. Record this insn if the register is only used once | |
1137 | more and the equivalence value is the same as our source. | |
1138 | ||
1139 | The latter condition is checked for two reasons: First, it is an | |
1140 | indication that it may be more efficient to actually emit the insn | |
1141 | as written (if no registers are available, reload will substitute | |
1142 | the equivalence). Secondly, it avoids problems with any registers | |
1143 | dying in this insn whose death notes would be missed. | |
1144 | ||
1145 | If we don't have a REG_EQUIV note, see if this insn is loading | |
1146 | a register used only in one basic block from a MEM. If so, and the | |
1147 | MEM remains unchanged for the life of the register, add a REG_EQUIV | |
1148 | note. */ | |
1149 | ||
b1ec3c92 | 1150 | note = find_reg_note (insn, REG_EQUIV, NULL_RTX); |
2bbd3819 | 1151 | |
b1f21e0a | 1152 | if (note == 0 && REG_BASIC_BLOCK (regno) >= 0 |
2bbd3819 RS |
1153 | && GET_CODE (SET_SRC (set)) == MEM |
1154 | && validate_equiv_mem (insn, dest, SET_SRC (set))) | |
1155 | REG_NOTES (insn) = note = gen_rtx (EXPR_LIST, REG_EQUIV, SET_SRC (set), | |
1156 | REG_NOTES (insn)); | |
1157 | ||
68342d36 | 1158 | if (note) |
2bbd3819 RS |
1159 | { |
1160 | int regno = REGNO (dest); | |
1161 | ||
68342d36 RK |
1162 | reg_equiv_replacement[regno] = XEXP (note, 0); |
1163 | ||
1164 | /* Don't mess with things live during setjmp. */ | |
b1f21e0a | 1165 | if (REG_LIVE_LENGTH (regno) >= 0) |
68342d36 RK |
1166 | { |
1167 | /* Note that the statement below does not affect the priority | |
1168 | in local-alloc! */ | |
b1f21e0a | 1169 | REG_LIVE_LENGTH (regno) *= 2; |
2bbd3819 | 1170 | |
2bbd3819 | 1171 | |
68342d36 RK |
1172 | /* If the register is referenced exactly twice, meaning it is |
1173 | set once and used once, indicate that the reference may be | |
1174 | replaced by the equivalence we computed above. If the | |
1175 | register is only used in one basic block, this can't succeed | |
1176 | or combine would have done it. | |
2bbd3819 | 1177 | |
68342d36 RK |
1178 | It would be nice to use "loop_depth * 2" in the compare |
1179 | below. Unfortunately, LOOP_DEPTH need not be constant within | |
1180 | a basic block so this would be too complicated. | |
2bbd3819 | 1181 | |
68342d36 RK |
1182 | This case normally occurs when a parameter is read from |
1183 | memory and then used exactly once, not in a loop. */ | |
1184 | ||
b1f21e0a MM |
1185 | if (REG_N_REFS (regno) == 2 |
1186 | && REG_BASIC_BLOCK (regno) < 0 | |
68342d36 RK |
1187 | && rtx_equal_p (XEXP (note, 0), SET_SRC (set))) |
1188 | reg_equiv_replace[regno] = 1; | |
1189 | } | |
2bbd3819 RS |
1190 | } |
1191 | } | |
1192 | ||
2e1253f3 ILT |
1193 | /* Now scan all regs killed in an insn to see if any of them are |
1194 | registers only used that once. If so, see if we can replace the | |
1195 | reference with the equivalent from. If we can, delete the | |
1196 | initializing reference and this register will go away. If we | |
1197 | can't replace the reference, and the instruction is not in a | |
1198 | loop, then move the register initialization just before the use, | |
1199 | so that they are in the same basic block. */ | |
1200 | block = -1; | |
1201 | depth = 0; | |
1202 | for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) | |
2bbd3819 RS |
1203 | { |
1204 | rtx link; | |
1205 | ||
2e1253f3 ILT |
1206 | /* Keep track of which basic block we are in. */ |
1207 | if (block + 1 < n_basic_blocks | |
1208 | && basic_block_head[block + 1] == insn) | |
1209 | ++block; | |
1210 | ||
1211 | if (GET_RTX_CLASS (GET_CODE (insn)) != 'i') | |
1212 | { | |
1213 | if (GET_CODE (insn) == NOTE) | |
1214 | { | |
1215 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG) | |
1216 | ++depth; | |
1217 | else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END) | |
1218 | { | |
1219 | --depth; | |
1220 | if (depth < 0) | |
1221 | abort (); | |
1222 | } | |
1223 | } | |
1224 | ||
1225 | continue; | |
1226 | } | |
1227 | ||
2bbd3819 | 1228 | for (link = REG_NOTES (insn); link; link = XEXP (link, 1)) |
2e1253f3 ILT |
1229 | { |
1230 | if (REG_NOTE_KIND (link) == REG_DEAD | |
1231 | /* Make sure this insn still refers to the register. */ | |
1232 | && reg_mentioned_p (XEXP (link, 0), PATTERN (insn))) | |
1233 | { | |
1234 | int regno = REGNO (XEXP (link, 0)); | |
1235 | rtx equiv_insn; | |
2bbd3819 | 1236 | |
2e1253f3 ILT |
1237 | if (! reg_equiv_replace[regno]) |
1238 | continue; | |
1239 | ||
1240 | equiv_insn = reg_equiv_init_insn[regno]; | |
1241 | ||
1242 | if (validate_replace_rtx (regno_reg_rtx[regno], | |
1243 | reg_equiv_replacement[regno], insn)) | |
1244 | { | |
1245 | remove_death (regno, insn); | |
b1f21e0a | 1246 | REG_N_REFS (regno) = 0; |
2e1253f3 ILT |
1247 | PUT_CODE (equiv_insn, NOTE); |
1248 | NOTE_LINE_NUMBER (equiv_insn) = NOTE_INSN_DELETED; | |
1249 | NOTE_SOURCE_FILE (equiv_insn) = 0; | |
1250 | } | |
1251 | /* If we aren't in a loop, and there are no calls in | |
1252 | INSN or in the initialization of the register, then | |
1253 | move the initialization of the register to just | |
1254 | before INSN. Update the flow information. */ | |
1255 | else if (depth == 0 | |
1256 | && GET_CODE (equiv_insn) == INSN | |
1257 | && GET_CODE (insn) == INSN | |
b1f21e0a | 1258 | && REG_BASIC_BLOCK (regno) < 0) |
2e1253f3 | 1259 | { |
8e08106d | 1260 | int l; |
2e1253f3 | 1261 | |
9956bfc0 RK |
1262 | emit_insn_before (copy_rtx (PATTERN (equiv_insn)), insn); |
1263 | REG_NOTES (PREV_INSN (insn)) = REG_NOTES (equiv_insn); | |
2e1253f3 ILT |
1264 | |
1265 | PUT_CODE (equiv_insn, NOTE); | |
1266 | NOTE_LINE_NUMBER (equiv_insn) = NOTE_INSN_DELETED; | |
1267 | NOTE_SOURCE_FILE (equiv_insn) = 0; | |
1268 | REG_NOTES (equiv_insn) = 0; | |
1269 | ||
1270 | if (block < 0) | |
b1f21e0a | 1271 | REG_BASIC_BLOCK (regno) = 0; |
2e1253f3 | 1272 | else |
b1f21e0a MM |
1273 | REG_BASIC_BLOCK (regno) = block; |
1274 | REG_N_CALLS_CROSSED (regno) = 0; | |
1275 | REG_LIVE_LENGTH (regno) = 2; | |
2e1253f3 ILT |
1276 | |
1277 | if (block >= 0 && insn == basic_block_head[block]) | |
1278 | basic_block_head[block] = PREV_INSN (insn); | |
1279 | ||
2e1253f3 | 1280 | for (l = 0; l < n_basic_blocks; l++) |
8e08106d | 1281 | CLEAR_REGNO_REG_SET (basic_block_live_at_start[l], regno); |
2e1253f3 ILT |
1282 | } |
1283 | } | |
1284 | } | |
2bbd3819 RS |
1285 | } |
1286 | } | |
1287 | \f | |
1288 | /* Allocate hard regs to the pseudo regs used only within block number B. | |
1289 | Only the pseudos that die but once can be handled. */ | |
1290 | ||
1291 | static void | |
1292 | block_alloc (b) | |
1293 | int b; | |
1294 | { | |
1295 | register int i, q; | |
1296 | register rtx insn; | |
1297 | rtx note; | |
1298 | int insn_number = 0; | |
1299 | int insn_count = 0; | |
1300 | int max_uid = get_max_uid (); | |
aabf56ce | 1301 | int *qty_order; |
2bbd3819 | 1302 | int no_conflict_combined_regno = -1; |
2a81034f JW |
1303 | /* Counter to prevent allocating more SCRATCHes than can be stored |
1304 | in SCRATCH_LIST. */ | |
1305 | int scratches_allocated = scratch_index; | |
2bbd3819 RS |
1306 | |
1307 | /* Count the instructions in the basic block. */ | |
1308 | ||
1309 | insn = basic_block_end[b]; | |
1310 | while (1) | |
1311 | { | |
1312 | if (GET_CODE (insn) != NOTE) | |
1313 | if (++insn_count > max_uid) | |
1314 | abort (); | |
1315 | if (insn == basic_block_head[b]) | |
1316 | break; | |
1317 | insn = PREV_INSN (insn); | |
1318 | } | |
1319 | ||
1320 | /* +2 to leave room for a post_mark_life at the last insn and for | |
1321 | the birth of a CLOBBER in the first insn. */ | |
1322 | regs_live_at = (HARD_REG_SET *) alloca ((2 * insn_count + 2) | |
1323 | * sizeof (HARD_REG_SET)); | |
4c9a05bc | 1324 | bzero ((char *) regs_live_at, (2 * insn_count + 2) * sizeof (HARD_REG_SET)); |
2bbd3819 RS |
1325 | |
1326 | /* Initialize table of hardware registers currently live. */ | |
1327 | ||
8e08106d | 1328 | REG_SET_TO_HARD_REG_SET (regs_live, basic_block_live_at_start[b]); |
2bbd3819 RS |
1329 | |
1330 | /* This loop scans the instructions of the basic block | |
1331 | and assigns quantities to registers. | |
1332 | It computes which registers to tie. */ | |
1333 | ||
1334 | insn = basic_block_head[b]; | |
1335 | while (1) | |
1336 | { | |
1337 | register rtx body = PATTERN (insn); | |
1338 | ||
1339 | if (GET_CODE (insn) != NOTE) | |
1340 | insn_number++; | |
1341 | ||
1342 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i') | |
1343 | { | |
1344 | register rtx link, set; | |
1345 | register int win = 0; | |
1346 | register rtx r0, r1; | |
1347 | int combined_regno = -1; | |
1348 | int i; | |
1349 | int insn_code_number = recog_memoized (insn); | |
1350 | ||
1351 | this_insn_number = insn_number; | |
1352 | this_insn = insn; | |
1353 | ||
1354 | if (insn_code_number >= 0) | |
1355 | insn_extract (insn); | |
1356 | which_alternative = -1; | |
1357 | ||
1358 | /* Is this insn suitable for tying two registers? | |
1359 | If so, try doing that. | |
1360 | Suitable insns are those with at least two operands and where | |
1361 | operand 0 is an output that is a register that is not | |
1362 | earlyclobber. | |
7aba0f0b RK |
1363 | |
1364 | We can tie operand 0 with some operand that dies in this insn. | |
1365 | First look for operands that are required to be in the same | |
1366 | register as operand 0. If we find such, only try tying that | |
1367 | operand or one that can be put into that operand if the | |
1368 | operation is commutative. If we don't find an operand | |
1369 | that is required to be in the same register as operand 0, | |
1370 | we can tie with any operand. | |
1371 | ||
2bbd3819 RS |
1372 | Subregs in place of regs are also ok. |
1373 | ||
1374 | If tying is done, WIN is set nonzero. */ | |
1375 | ||
1376 | if (insn_code_number >= 0 | |
7fe4336e | 1377 | #ifdef REGISTER_CONSTRAINTS |
2bbd3819 RS |
1378 | && insn_n_operands[insn_code_number] > 1 |
1379 | && insn_operand_constraint[insn_code_number][0][0] == '=' | |
7fe4336e RK |
1380 | && insn_operand_constraint[insn_code_number][0][1] != '&' |
1381 | #else | |
1382 | && GET_CODE (PATTERN (insn)) == SET | |
1383 | && rtx_equal_p (SET_DEST (PATTERN (insn)), recog_operand[0]) | |
1384 | #endif | |
1385 | ) | |
2bbd3819 | 1386 | { |
7fe4336e | 1387 | #ifdef REGISTER_CONSTRAINTS |
3061cc54 | 1388 | /* If non-negative, is an operand that must match operand 0. */ |
7aba0f0b | 1389 | int must_match_0 = -1; |
3061cc54 RK |
1390 | /* Counts number of alternatives that require a match with |
1391 | operand 0. */ | |
1392 | int n_matching_alts = 0; | |
7aba0f0b RK |
1393 | |
1394 | for (i = 1; i < insn_n_operands[insn_code_number]; i++) | |
3061cc54 RK |
1395 | { |
1396 | char *p = insn_operand_constraint[insn_code_number][i]; | |
1397 | int this_match = (requires_inout (p)); | |
1398 | ||
1399 | n_matching_alts += this_match; | |
1400 | if (this_match == insn_n_alternatives[insn_code_number]) | |
1401 | must_match_0 = i; | |
1402 | } | |
7fe4336e | 1403 | #endif |
2bbd3819 | 1404 | |
7aba0f0b RK |
1405 | r0 = recog_operand[0]; |
1406 | for (i = 1; i < insn_n_operands[insn_code_number]; i++) | |
2bbd3819 | 1407 | { |
7fe4336e | 1408 | #ifdef REGISTER_CONSTRAINTS |
7aba0f0b RK |
1409 | /* Skip this operand if we found an operand that |
1410 | must match operand 0 and this operand isn't it | |
1411 | and can't be made to be it by commutativity. */ | |
1412 | ||
1413 | if (must_match_0 >= 0 && i != must_match_0 | |
1414 | && ! (i == must_match_0 + 1 | |
1415 | && insn_operand_constraint[insn_code_number][i-1][0] == '%') | |
1416 | && ! (i == must_match_0 - 1 | |
1417 | && insn_operand_constraint[insn_code_number][i][0] == '%')) | |
1418 | continue; | |
3061cc54 RK |
1419 | |
1420 | /* Likewise if each alternative has some operand that | |
1421 | must match operand zero. In that case, skip any | |
1422 | operand that doesn't list operand 0 since we know that | |
1423 | the operand always conflicts with operand 0. We | |
1424 | ignore commutatity in this case to keep things simple. */ | |
1425 | if (n_matching_alts == insn_n_alternatives[insn_code_number] | |
1426 | && (0 == requires_inout | |
1427 | (insn_operand_constraint[insn_code_number][i]))) | |
1428 | continue; | |
7fe4336e | 1429 | #endif |
2bbd3819 | 1430 | |
7aba0f0b | 1431 | r1 = recog_operand[i]; |
2bbd3819 | 1432 | |
7aba0f0b RK |
1433 | /* If the operand is an address, find a register in it. |
1434 | There may be more than one register, but we only try one | |
1435 | of them. */ | |
1436 | if ( | |
7fe4336e | 1437 | #ifdef REGISTER_CONSTRAINTS |
7aba0f0b | 1438 | insn_operand_constraint[insn_code_number][i][0] == 'p' |
7fe4336e | 1439 | #else |
7aba0f0b | 1440 | insn_operand_address_p[insn_code_number][i] |
7fe4336e | 1441 | #endif |
7aba0f0b RK |
1442 | ) |
1443 | while (GET_CODE (r1) == PLUS || GET_CODE (r1) == MULT) | |
1444 | r1 = XEXP (r1, 0); | |
1445 | ||
1446 | if (GET_CODE (r0) == REG || GET_CODE (r0) == SUBREG) | |
1447 | { | |
1448 | /* We have two priorities for hard register preferences. | |
1449 | If we have a move insn or an insn whose first input | |
1450 | can only be in the same register as the output, give | |
1451 | priority to an equivalence found from that insn. */ | |
1452 | int may_save_copy | |
1453 | = ((SET_DEST (body) == r0 && SET_SRC (body) == r1) | |
1454 | #ifdef REGISTER_CONSTRAINTS | |
1455 | || (r1 == recog_operand[i] && must_match_0 >= 0) | |
1456 | #endif | |
1457 | ); | |
1458 | ||
1459 | if (GET_CODE (r1) == REG || GET_CODE (r1) == SUBREG) | |
1460 | win = combine_regs (r1, r0, may_save_copy, | |
1461 | insn_number, insn, 0); | |
1462 | } | |
662347c5 JL |
1463 | if (win) |
1464 | break; | |
2bbd3819 RS |
1465 | } |
1466 | } | |
1467 | ||
1468 | /* Recognize an insn sequence with an ultimate result | |
1469 | which can safely overlap one of the inputs. | |
1470 | The sequence begins with a CLOBBER of its result, | |
1471 | and ends with an insn that copies the result to itself | |
1472 | and has a REG_EQUAL note for an equivalent formula. | |
1473 | That note indicates what the inputs are. | |
1474 | The result and the input can overlap if each insn in | |
1475 | the sequence either doesn't mention the input | |
1476 | or has a REG_NO_CONFLICT note to inhibit the conflict. | |
1477 | ||
1478 | We do the combining test at the CLOBBER so that the | |
1479 | destination register won't have had a quantity number | |
1480 | assigned, since that would prevent combining. */ | |
1481 | ||
1482 | if (GET_CODE (PATTERN (insn)) == CLOBBER | |
1483 | && (r0 = XEXP (PATTERN (insn), 0), | |
1484 | GET_CODE (r0) == REG) | |
b1ec3c92 | 1485 | && (link = find_reg_note (insn, REG_LIBCALL, NULL_RTX)) != 0 |
a6665f8c | 1486 | && XEXP (link, 0) != 0 |
2bbd3819 RS |
1487 | && GET_CODE (XEXP (link, 0)) == INSN |
1488 | && (set = single_set (XEXP (link, 0))) != 0 | |
1489 | && SET_DEST (set) == r0 && SET_SRC (set) == r0 | |
b1ec3c92 CH |
1490 | && (note = find_reg_note (XEXP (link, 0), REG_EQUAL, |
1491 | NULL_RTX)) != 0) | |
2bbd3819 RS |
1492 | { |
1493 | if (r1 = XEXP (note, 0), GET_CODE (r1) == REG | |
1494 | /* Check that we have such a sequence. */ | |
1495 | && no_conflict_p (insn, r0, r1)) | |
1496 | win = combine_regs (r1, r0, 1, insn_number, insn, 1); | |
1497 | else if (GET_RTX_FORMAT (GET_CODE (XEXP (note, 0)))[0] == 'e' | |
1498 | && (r1 = XEXP (XEXP (note, 0), 0), | |
1499 | GET_CODE (r1) == REG || GET_CODE (r1) == SUBREG) | |
1500 | && no_conflict_p (insn, r0, r1)) | |
1501 | win = combine_regs (r1, r0, 0, insn_number, insn, 1); | |
1502 | ||
1503 | /* Here we care if the operation to be computed is | |
1504 | commutative. */ | |
1505 | else if ((GET_CODE (XEXP (note, 0)) == EQ | |
1506 | || GET_CODE (XEXP (note, 0)) == NE | |
1507 | || GET_RTX_CLASS (GET_CODE (XEXP (note, 0))) == 'c') | |
1508 | && (r1 = XEXP (XEXP (note, 0), 1), | |
1509 | (GET_CODE (r1) == REG || GET_CODE (r1) == SUBREG)) | |
1510 | && no_conflict_p (insn, r0, r1)) | |
1511 | win = combine_regs (r1, r0, 0, insn_number, insn, 1); | |
1512 | ||
1513 | /* If we did combine something, show the register number | |
1514 | in question so that we know to ignore its death. */ | |
1515 | if (win) | |
1516 | no_conflict_combined_regno = REGNO (r1); | |
1517 | } | |
1518 | ||
1519 | /* If registers were just tied, set COMBINED_REGNO | |
1520 | to the number of the register used in this insn | |
1521 | that was tied to the register set in this insn. | |
1522 | This register's qty should not be "killed". */ | |
1523 | ||
1524 | if (win) | |
1525 | { | |
1526 | while (GET_CODE (r1) == SUBREG) | |
1527 | r1 = SUBREG_REG (r1); | |
1528 | combined_regno = REGNO (r1); | |
1529 | } | |
1530 | ||
1531 | /* Mark the death of everything that dies in this instruction, | |
1532 | except for anything that was just combined. */ | |
1533 | ||
1534 | for (link = REG_NOTES (insn); link; link = XEXP (link, 1)) | |
1535 | if (REG_NOTE_KIND (link) == REG_DEAD | |
1536 | && GET_CODE (XEXP (link, 0)) == REG | |
1537 | && combined_regno != REGNO (XEXP (link, 0)) | |
1538 | && (no_conflict_combined_regno != REGNO (XEXP (link, 0)) | |
1539 | || ! find_reg_note (insn, REG_NO_CONFLICT, XEXP (link, 0)))) | |
1540 | wipe_dead_reg (XEXP (link, 0), 0); | |
1541 | ||
1542 | /* Allocate qty numbers for all registers local to this block | |
1543 | that are born (set) in this instruction. | |
1544 | A pseudo that already has a qty is not changed. */ | |
1545 | ||
1546 | note_stores (PATTERN (insn), reg_is_set); | |
1547 | ||
1548 | /* If anything is set in this insn and then unused, mark it as dying | |
1549 | after this insn, so it will conflict with our outputs. This | |
1550 | can't match with something that combined, and it doesn't matter | |
1551 | if it did. Do this after the calls to reg_is_set since these | |
1552 | die after, not during, the current insn. */ | |
1553 | ||
1554 | for (link = REG_NOTES (insn); link; link = XEXP (link, 1)) | |
1555 | if (REG_NOTE_KIND (link) == REG_UNUSED | |
1556 | && GET_CODE (XEXP (link, 0)) == REG) | |
1557 | wipe_dead_reg (XEXP (link, 0), 1); | |
1558 | ||
e15eb3aa | 1559 | /* Allocate quantities for any SCRATCH operands of this insn. */ |
2bbd3819 RS |
1560 | |
1561 | if (insn_code_number >= 0) | |
1562 | for (i = 0; i < insn_n_operands[insn_code_number]; i++) | |
bd5f197a | 1563 | if (GET_CODE (recog_operand[i]) == SCRATCH |
2a81034f | 1564 | && scratches_allocated++ < scratch_list_length) |
2bbd3819 RS |
1565 | alloc_qty_for_scratch (recog_operand[i], i, insn, |
1566 | insn_code_number, insn_number); | |
2bbd3819 RS |
1567 | |
1568 | /* If this is an insn that has a REG_RETVAL note pointing at a | |
1569 | CLOBBER insn, we have reached the end of a REG_NO_CONFLICT | |
1570 | block, so clear any register number that combined within it. */ | |
b1ec3c92 | 1571 | if ((note = find_reg_note (insn, REG_RETVAL, NULL_RTX)) != 0 |
2bbd3819 RS |
1572 | && GET_CODE (XEXP (note, 0)) == INSN |
1573 | && GET_CODE (PATTERN (XEXP (note, 0))) == CLOBBER) | |
1574 | no_conflict_combined_regno = -1; | |
1575 | } | |
1576 | ||
1577 | /* Set the registers live after INSN_NUMBER. Note that we never | |
1578 | record the registers live before the block's first insn, since no | |
1579 | pseudos we care about are live before that insn. */ | |
1580 | ||
1581 | IOR_HARD_REG_SET (regs_live_at[2 * insn_number], regs_live); | |
1582 | IOR_HARD_REG_SET (regs_live_at[2 * insn_number + 1], regs_live); | |
1583 | ||
1584 | if (insn == basic_block_end[b]) | |
1585 | break; | |
1586 | ||
1587 | insn = NEXT_INSN (insn); | |
1588 | } | |
1589 | ||
1590 | /* Now every register that is local to this basic block | |
1591 | should have been given a quantity, or else -1 meaning ignore it. | |
1592 | Every quantity should have a known birth and death. | |
1593 | ||
51b86d8b RK |
1594 | Order the qtys so we assign them registers in order of the |
1595 | number of suggested registers they need so we allocate those with | |
1596 | the most restrictive needs first. */ | |
2bbd3819 | 1597 | |
aabf56ce | 1598 | qty_order = (int *) alloca (next_qty * sizeof (int)); |
2bbd3819 RS |
1599 | for (i = 0; i < next_qty; i++) |
1600 | qty_order[i] = i; | |
1601 | ||
1602 | #define EXCHANGE(I1, I2) \ | |
1603 | { i = qty_order[I1]; qty_order[I1] = qty_order[I2]; qty_order[I2] = i; } | |
1604 | ||
1605 | switch (next_qty) | |
1606 | { | |
1607 | case 3: | |
1608 | /* Make qty_order[2] be the one to allocate last. */ | |
51b86d8b | 1609 | if (qty_sugg_compare (0, 1) > 0) |
2bbd3819 | 1610 | EXCHANGE (0, 1); |
51b86d8b | 1611 | if (qty_sugg_compare (1, 2) > 0) |
2bbd3819 RS |
1612 | EXCHANGE (2, 1); |
1613 | ||
0f41302f | 1614 | /* ... Fall through ... */ |
2bbd3819 RS |
1615 | case 2: |
1616 | /* Put the best one to allocate in qty_order[0]. */ | |
51b86d8b | 1617 | if (qty_sugg_compare (0, 1) > 0) |
2bbd3819 RS |
1618 | EXCHANGE (0, 1); |
1619 | ||
0f41302f | 1620 | /* ... Fall through ... */ |
2bbd3819 RS |
1621 | |
1622 | case 1: | |
1623 | case 0: | |
1624 | /* Nothing to do here. */ | |
1625 | break; | |
1626 | ||
1627 | default: | |
51b86d8b | 1628 | qsort (qty_order, next_qty, sizeof (int), qty_sugg_compare_1); |
2bbd3819 RS |
1629 | } |
1630 | ||
1631 | /* Try to put each quantity in a suggested physical register, if it has one. | |
1632 | This may cause registers to be allocated that otherwise wouldn't be, but | |
1633 | this seems acceptable in local allocation (unlike global allocation). */ | |
1634 | for (i = 0; i < next_qty; i++) | |
1635 | { | |
1636 | q = qty_order[i]; | |
51b86d8b | 1637 | if (qty_phys_num_sugg[q] != 0 || qty_phys_num_copy_sugg[q] != 0) |
2bbd3819 RS |
1638 | qty_phys_reg[q] = find_free_reg (qty_min_class[q], qty_mode[q], q, |
1639 | 0, 1, qty_birth[q], qty_death[q]); | |
1640 | else | |
1641 | qty_phys_reg[q] = -1; | |
1642 | } | |
1643 | ||
51b86d8b RK |
1644 | /* Order the qtys so we assign them registers in order of |
1645 | decreasing length of life. Normally call qsort, but if we | |
1646 | have only a very small number of quantities, sort them ourselves. */ | |
1647 | ||
1648 | for (i = 0; i < next_qty; i++) | |
1649 | qty_order[i] = i; | |
1650 | ||
1651 | #define EXCHANGE(I1, I2) \ | |
1652 | { i = qty_order[I1]; qty_order[I1] = qty_order[I2]; qty_order[I2] = i; } | |
1653 | ||
1654 | switch (next_qty) | |
1655 | { | |
1656 | case 3: | |
1657 | /* Make qty_order[2] be the one to allocate last. */ | |
1658 | if (qty_compare (0, 1) > 0) | |
1659 | EXCHANGE (0, 1); | |
1660 | if (qty_compare (1, 2) > 0) | |
1661 | EXCHANGE (2, 1); | |
1662 | ||
0f41302f | 1663 | /* ... Fall through ... */ |
51b86d8b RK |
1664 | case 2: |
1665 | /* Put the best one to allocate in qty_order[0]. */ | |
1666 | if (qty_compare (0, 1) > 0) | |
1667 | EXCHANGE (0, 1); | |
1668 | ||
0f41302f | 1669 | /* ... Fall through ... */ |
51b86d8b RK |
1670 | |
1671 | case 1: | |
1672 | case 0: | |
1673 | /* Nothing to do here. */ | |
1674 | break; | |
1675 | ||
1676 | default: | |
1677 | qsort (qty_order, next_qty, sizeof (int), qty_compare_1); | |
1678 | } | |
1679 | ||
2bbd3819 RS |
1680 | /* Now for each qty that is not a hardware register, |
1681 | look for a hardware register to put it in. | |
1682 | First try the register class that is cheapest for this qty, | |
1683 | if there is more than one class. */ | |
1684 | ||
1685 | for (i = 0; i < next_qty; i++) | |
1686 | { | |
1687 | q = qty_order[i]; | |
1688 | if (qty_phys_reg[q] < 0) | |
1689 | { | |
1690 | if (N_REG_CLASSES > 1) | |
1691 | { | |
1692 | qty_phys_reg[q] = find_free_reg (qty_min_class[q], | |
1693 | qty_mode[q], q, 0, 0, | |
1694 | qty_birth[q], qty_death[q]); | |
1695 | if (qty_phys_reg[q] >= 0) | |
1696 | continue; | |
1697 | } | |
1698 | ||
e4600702 RK |
1699 | if (qty_alternate_class[q] != NO_REGS) |
1700 | qty_phys_reg[q] = find_free_reg (qty_alternate_class[q], | |
2bbd3819 RS |
1701 | qty_mode[q], q, 0, 0, |
1702 | qty_birth[q], qty_death[q]); | |
1703 | } | |
1704 | } | |
1705 | ||
1706 | /* Now propagate the register assignments | |
1707 | to the pseudo regs belonging to the qtys. */ | |
1708 | ||
1709 | for (q = 0; q < next_qty; q++) | |
1710 | if (qty_phys_reg[q] >= 0) | |
1711 | { | |
1712 | for (i = qty_first_reg[q]; i >= 0; i = reg_next_in_qty[i]) | |
1713 | reg_renumber[i] = qty_phys_reg[q] + reg_offset[i]; | |
1714 | if (qty_scratch_rtx[q]) | |
1715 | { | |
bd5f197a RK |
1716 | if (GET_CODE (qty_scratch_rtx[q]) == REG) |
1717 | abort (); | |
0bd83abd JL |
1718 | qty_scratch_rtx[q] = gen_rtx (REG, GET_MODE (qty_scratch_rtx[q]), |
1719 | qty_phys_reg[q]); | |
bd5f197a RK |
1720 | scratch_block[scratch_index] = b; |
1721 | scratch_list[scratch_index++] = qty_scratch_rtx[q]; | |
956d6950 | 1722 | |
2bbd3819 RS |
1723 | } |
1724 | } | |
1725 | } | |
1726 | \f | |
1727 | /* Compare two quantities' priority for getting real registers. | |
1728 | We give shorter-lived quantities higher priority. | |
6dc42e49 RS |
1729 | Quantities with more references are also preferred, as are quantities that |
1730 | require multiple registers. This is the identical prioritization as | |
2bbd3819 RS |
1731 | done by global-alloc. |
1732 | ||
1733 | We used to give preference to registers with *longer* lives, but using | |
1734 | the same algorithm in both local- and global-alloc can speed up execution | |
1735 | of some programs by as much as a factor of three! */ | |
1736 | ||
2f23fcc9 RK |
1737 | /* Note that the quotient will never be bigger than |
1738 | the value of floor_log2 times the maximum number of | |
1739 | times a register can occur in one insn (surely less than 100). | |
1740 | Multiplying this by 10000 can't overflow. | |
1741 | QTY_CMP_PRI is also used by qty_sugg_compare. */ | |
1742 | ||
1743 | #define QTY_CMP_PRI(q) \ | |
1744 | ((int) (((double) (floor_log2 (qty_n_refs[q]) * qty_n_refs[q] * qty_size[q]) \ | |
1745 | / (qty_death[q] - qty_birth[q])) * 10000)) | |
1746 | ||
2bbd3819 RS |
1747 | static int |
1748 | qty_compare (q1, q2) | |
1749 | int q1, q2; | |
1750 | { | |
2f23fcc9 | 1751 | return QTY_CMP_PRI (q2) - QTY_CMP_PRI (q1); |
2bbd3819 RS |
1752 | } |
1753 | ||
1754 | static int | |
2f23fcc9 RK |
1755 | qty_compare_1 (q1p, q2p) |
1756 | const GENERIC_PTR q1p; | |
1757 | const GENERIC_PTR q2p; | |
2bbd3819 | 1758 | { |
2f23fcc9 RK |
1759 | register int q1 = *(int *)q1p, q2 = *(int *)q2p; |
1760 | register int tem = QTY_CMP_PRI (q2) - QTY_CMP_PRI (q1); | |
1761 | ||
1762 | if (tem != 0) | |
1763 | return tem; | |
1764 | ||
2bbd3819 RS |
1765 | /* If qtys are equally good, sort by qty number, |
1766 | so that the results of qsort leave nothing to chance. */ | |
2f23fcc9 | 1767 | return q1 - q2; |
2bbd3819 RS |
1768 | } |
1769 | \f | |
51b86d8b RK |
1770 | /* Compare two quantities' priority for getting real registers. This version |
1771 | is called for quantities that have suggested hard registers. First priority | |
1772 | goes to quantities that have copy preferences, then to those that have | |
1773 | normal preferences. Within those groups, quantities with the lower | |
9faa82d8 | 1774 | number of preferences have the highest priority. Of those, we use the same |
51b86d8b RK |
1775 | algorithm as above. */ |
1776 | ||
2f23fcc9 RK |
1777 | #define QTY_CMP_SUGG(q) \ |
1778 | (qty_phys_num_copy_sugg[q] \ | |
1779 | ? qty_phys_num_copy_sugg[q] \ | |
1780 | : qty_phys_num_sugg[q] * FIRST_PSEUDO_REGISTER) | |
1781 | ||
51b86d8b RK |
1782 | static int |
1783 | qty_sugg_compare (q1, q2) | |
1784 | int q1, q2; | |
1785 | { | |
2f23fcc9 RK |
1786 | register int tem = QTY_CMP_SUGG (q1) - QTY_CMP_SUGG (q2); |
1787 | ||
1788 | if (tem != 0) | |
1789 | return tem; | |
51b86d8b | 1790 | |
2f23fcc9 | 1791 | return QTY_CMP_PRI (q2) - QTY_CMP_PRI (q1); |
51b86d8b RK |
1792 | } |
1793 | ||
1794 | static int | |
2f23fcc9 RK |
1795 | qty_sugg_compare_1 (q1p, q2p) |
1796 | const GENERIC_PTR q1p; | |
1797 | const GENERIC_PTR q2p; | |
51b86d8b | 1798 | { |
2f23fcc9 RK |
1799 | register int q1 = *(int *)q1p, q2 = *(int *)q2p; |
1800 | register int tem = QTY_CMP_SUGG (q1) - QTY_CMP_SUGG (q2); | |
1801 | ||
1802 | if (tem != 0) | |
1803 | return tem; | |
1804 | ||
1805 | tem = QTY_CMP_PRI (q2) - QTY_CMP_PRI (q1); | |
1806 | if (tem != 0) | |
1807 | return tem; | |
51b86d8b RK |
1808 | |
1809 | /* If qtys are equally good, sort by qty number, | |
1810 | so that the results of qsort leave nothing to chance. */ | |
2f23fcc9 | 1811 | return q1 - q2; |
51b86d8b | 1812 | } |
2f23fcc9 RK |
1813 | |
1814 | #undef QTY_CMP_SUGG | |
1815 | #undef QTY_CMP_PRI | |
51b86d8b | 1816 | \f |
2bbd3819 RS |
1817 | /* Attempt to combine the two registers (rtx's) USEDREG and SETREG. |
1818 | Returns 1 if have done so, or 0 if cannot. | |
1819 | ||
1820 | Combining registers means marking them as having the same quantity | |
1821 | and adjusting the offsets within the quantity if either of | |
1822 | them is a SUBREG). | |
1823 | ||
1824 | We don't actually combine a hard reg with a pseudo; instead | |
1825 | we just record the hard reg as the suggestion for the pseudo's quantity. | |
1826 | If we really combined them, we could lose if the pseudo lives | |
1827 | across an insn that clobbers the hard reg (eg, movstr). | |
1828 | ||
1829 | ALREADY_DEAD is non-zero if USEDREG is known to be dead even though | |
1830 | there is no REG_DEAD note on INSN. This occurs during the processing | |
1831 | of REG_NO_CONFLICT blocks. | |
1832 | ||
1833 | MAY_SAVE_COPYCOPY is non-zero if this insn is simply copying USEDREG to | |
1834 | SETREG or if the input and output must share a register. | |
1835 | In that case, we record a hard reg suggestion in QTY_PHYS_COPY_SUGG. | |
1836 | ||
1837 | There are elaborate checks for the validity of combining. */ | |
1838 | ||
1839 | ||
1840 | static int | |
1841 | combine_regs (usedreg, setreg, may_save_copy, insn_number, insn, already_dead) | |
1842 | rtx usedreg, setreg; | |
1843 | int may_save_copy; | |
1844 | int insn_number; | |
1845 | rtx insn; | |
1846 | int already_dead; | |
1847 | { | |
1848 | register int ureg, sreg; | |
1849 | register int offset = 0; | |
1850 | int usize, ssize; | |
1851 | register int sqty; | |
1852 | ||
1853 | /* Determine the numbers and sizes of registers being used. If a subreg | |
6dc42e49 | 1854 | is present that does not change the entire register, don't consider |
2bbd3819 RS |
1855 | this a copy insn. */ |
1856 | ||
1857 | while (GET_CODE (usedreg) == SUBREG) | |
1858 | { | |
1859 | if (GET_MODE_SIZE (GET_MODE (SUBREG_REG (usedreg))) > UNITS_PER_WORD) | |
1860 | may_save_copy = 0; | |
1861 | offset += SUBREG_WORD (usedreg); | |
1862 | usedreg = SUBREG_REG (usedreg); | |
1863 | } | |
1864 | if (GET_CODE (usedreg) != REG) | |
1865 | return 0; | |
1866 | ureg = REGNO (usedreg); | |
1867 | usize = REG_SIZE (usedreg); | |
1868 | ||
1869 | while (GET_CODE (setreg) == SUBREG) | |
1870 | { | |
1871 | if (GET_MODE_SIZE (GET_MODE (SUBREG_REG (setreg))) > UNITS_PER_WORD) | |
1872 | may_save_copy = 0; | |
1873 | offset -= SUBREG_WORD (setreg); | |
1874 | setreg = SUBREG_REG (setreg); | |
1875 | } | |
1876 | if (GET_CODE (setreg) != REG) | |
1877 | return 0; | |
1878 | sreg = REGNO (setreg); | |
1879 | ssize = REG_SIZE (setreg); | |
1880 | ||
1881 | /* If UREG is a pseudo-register that hasn't already been assigned a | |
1882 | quantity number, it means that it is not local to this block or dies | |
1883 | more than once. In either event, we can't do anything with it. */ | |
1884 | if ((ureg >= FIRST_PSEUDO_REGISTER && reg_qty[ureg] < 0) | |
1885 | /* Do not combine registers unless one fits within the other. */ | |
1886 | || (offset > 0 && usize + offset > ssize) | |
1887 | || (offset < 0 && usize + offset < ssize) | |
1888 | /* Do not combine with a smaller already-assigned object | |
0f41302f | 1889 | if that smaller object is already combined with something bigger. */ |
2bbd3819 RS |
1890 | || (ssize > usize && ureg >= FIRST_PSEUDO_REGISTER |
1891 | && usize < qty_size[reg_qty[ureg]]) | |
1892 | /* Can't combine if SREG is not a register we can allocate. */ | |
1893 | || (sreg >= FIRST_PSEUDO_REGISTER && reg_qty[sreg] == -1) | |
1894 | /* Don't combine with a pseudo mentioned in a REG_NO_CONFLICT note. | |
1895 | These have already been taken care of. This probably wouldn't | |
1896 | combine anyway, but don't take any chances. */ | |
1897 | || (ureg >= FIRST_PSEUDO_REGISTER | |
1898 | && find_reg_note (insn, REG_NO_CONFLICT, usedreg)) | |
1899 | /* Don't tie something to itself. In most cases it would make no | |
1900 | difference, but it would screw up if the reg being tied to itself | |
1901 | also dies in this insn. */ | |
1902 | || ureg == sreg | |
1903 | /* Don't try to connect two different hardware registers. */ | |
1904 | || (ureg < FIRST_PSEUDO_REGISTER && sreg < FIRST_PSEUDO_REGISTER) | |
1905 | /* Don't connect two different machine modes if they have different | |
1906 | implications as to which registers may be used. */ | |
1907 | || !MODES_TIEABLE_P (GET_MODE (usedreg), GET_MODE (setreg))) | |
1908 | return 0; | |
1909 | ||
1910 | /* Now, if UREG is a hard reg and SREG is a pseudo, record the hard reg in | |
1911 | qty_phys_sugg for the pseudo instead of tying them. | |
1912 | ||
1913 | Return "failure" so that the lifespan of UREG is terminated here; | |
1914 | that way the two lifespans will be disjoint and nothing will prevent | |
1915 | the pseudo reg from being given this hard reg. */ | |
1916 | ||
1917 | if (ureg < FIRST_PSEUDO_REGISTER) | |
1918 | { | |
1919 | /* Allocate a quantity number so we have a place to put our | |
1920 | suggestions. */ | |
1921 | if (reg_qty[sreg] == -2) | |
1922 | reg_is_born (setreg, 2 * insn_number); | |
1923 | ||
1924 | if (reg_qty[sreg] >= 0) | |
1925 | { | |
51b86d8b RK |
1926 | if (may_save_copy |
1927 | && ! TEST_HARD_REG_BIT (qty_phys_copy_sugg[reg_qty[sreg]], ureg)) | |
2bbd3819 RS |
1928 | { |
1929 | SET_HARD_REG_BIT (qty_phys_copy_sugg[reg_qty[sreg]], ureg); | |
51b86d8b | 1930 | qty_phys_num_copy_sugg[reg_qty[sreg]]++; |
2bbd3819 | 1931 | } |
51b86d8b | 1932 | else if (! TEST_HARD_REG_BIT (qty_phys_sugg[reg_qty[sreg]], ureg)) |
2bbd3819 RS |
1933 | { |
1934 | SET_HARD_REG_BIT (qty_phys_sugg[reg_qty[sreg]], ureg); | |
51b86d8b | 1935 | qty_phys_num_sugg[reg_qty[sreg]]++; |
2bbd3819 RS |
1936 | } |
1937 | } | |
1938 | return 0; | |
1939 | } | |
1940 | ||
1941 | /* Similarly for SREG a hard register and UREG a pseudo register. */ | |
1942 | ||
1943 | if (sreg < FIRST_PSEUDO_REGISTER) | |
1944 | { | |
51b86d8b RK |
1945 | if (may_save_copy |
1946 | && ! TEST_HARD_REG_BIT (qty_phys_copy_sugg[reg_qty[ureg]], sreg)) | |
2bbd3819 RS |
1947 | { |
1948 | SET_HARD_REG_BIT (qty_phys_copy_sugg[reg_qty[ureg]], sreg); | |
51b86d8b | 1949 | qty_phys_num_copy_sugg[reg_qty[ureg]]++; |
2bbd3819 | 1950 | } |
51b86d8b | 1951 | else if (! TEST_HARD_REG_BIT (qty_phys_sugg[reg_qty[ureg]], sreg)) |
2bbd3819 RS |
1952 | { |
1953 | SET_HARD_REG_BIT (qty_phys_sugg[reg_qty[ureg]], sreg); | |
51b86d8b | 1954 | qty_phys_num_sugg[reg_qty[ureg]]++; |
2bbd3819 RS |
1955 | } |
1956 | return 0; | |
1957 | } | |
1958 | ||
1959 | /* At this point we know that SREG and UREG are both pseudos. | |
1960 | Do nothing if SREG already has a quantity or is a register that we | |
1961 | don't allocate. */ | |
1962 | if (reg_qty[sreg] >= -1 | |
1963 | /* If we are not going to let any regs live across calls, | |
1964 | don't tie a call-crossing reg to a non-call-crossing reg. */ | |
1965 | || (current_function_has_nonlocal_label | |
b1f21e0a MM |
1966 | && ((REG_N_CALLS_CROSSED (ureg) > 0) |
1967 | != (REG_N_CALLS_CROSSED (sreg) > 0)))) | |
2bbd3819 RS |
1968 | return 0; |
1969 | ||
1970 | /* We don't already know about SREG, so tie it to UREG | |
1971 | if this is the last use of UREG, provided the classes they want | |
1972 | are compatible. */ | |
1973 | ||
1974 | if ((already_dead || find_regno_note (insn, REG_DEAD, ureg)) | |
1975 | && reg_meets_class_p (sreg, qty_min_class[reg_qty[ureg]])) | |
1976 | { | |
1977 | /* Add SREG to UREG's quantity. */ | |
1978 | sqty = reg_qty[ureg]; | |
1979 | reg_qty[sreg] = sqty; | |
1980 | reg_offset[sreg] = reg_offset[ureg] + offset; | |
1981 | reg_next_in_qty[sreg] = qty_first_reg[sqty]; | |
1982 | qty_first_reg[sqty] = sreg; | |
1983 | ||
1984 | /* If SREG's reg class is smaller, set qty_min_class[SQTY]. */ | |
1985 | update_qty_class (sqty, sreg); | |
1986 | ||
1987 | /* Update info about quantity SQTY. */ | |
b1f21e0a MM |
1988 | qty_n_calls_crossed[sqty] += REG_N_CALLS_CROSSED (sreg); |
1989 | qty_n_refs[sqty] += REG_N_REFS (sreg); | |
2bbd3819 RS |
1990 | if (usize < ssize) |
1991 | { | |
1992 | register int i; | |
1993 | ||
1994 | for (i = qty_first_reg[sqty]; i >= 0; i = reg_next_in_qty[i]) | |
1995 | reg_offset[i] -= offset; | |
1996 | ||
1997 | qty_size[sqty] = ssize; | |
1998 | qty_mode[sqty] = GET_MODE (setreg); | |
1999 | } | |
2000 | } | |
2001 | else | |
2002 | return 0; | |
2003 | ||
2004 | return 1; | |
2005 | } | |
2006 | \f | |
2007 | /* Return 1 if the preferred class of REG allows it to be tied | |
2008 | to a quantity or register whose class is CLASS. | |
2009 | True if REG's reg class either contains or is contained in CLASS. */ | |
2010 | ||
2011 | static int | |
2012 | reg_meets_class_p (reg, class) | |
2013 | int reg; | |
2014 | enum reg_class class; | |
2015 | { | |
2016 | register enum reg_class rclass = reg_preferred_class (reg); | |
2017 | return (reg_class_subset_p (rclass, class) | |
2018 | || reg_class_subset_p (class, rclass)); | |
2019 | } | |
2020 | ||
2021 | /* Return 1 if the two specified classes have registers in common. | |
2022 | If CALL_SAVED, then consider only call-saved registers. */ | |
2023 | ||
2024 | static int | |
2025 | reg_classes_overlap_p (c1, c2, call_saved) | |
2026 | register enum reg_class c1; | |
2027 | register enum reg_class c2; | |
2028 | int call_saved; | |
2029 | { | |
2030 | HARD_REG_SET c; | |
2031 | int i; | |
2032 | ||
2033 | COPY_HARD_REG_SET (c, reg_class_contents[(int) c1]); | |
2034 | AND_HARD_REG_SET (c, reg_class_contents[(int) c2]); | |
2035 | ||
2036 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
2037 | if (TEST_HARD_REG_BIT (c, i) | |
2038 | && (! call_saved || ! call_used_regs[i])) | |
2039 | return 1; | |
2040 | ||
2041 | return 0; | |
2042 | } | |
2043 | ||
2044 | /* Update the class of QTY assuming that REG is being tied to it. */ | |
2045 | ||
2046 | static void | |
2047 | update_qty_class (qty, reg) | |
2048 | int qty; | |
2049 | int reg; | |
2050 | { | |
2051 | enum reg_class rclass = reg_preferred_class (reg); | |
2052 | if (reg_class_subset_p (rclass, qty_min_class[qty])) | |
2053 | qty_min_class[qty] = rclass; | |
e4600702 RK |
2054 | |
2055 | rclass = reg_alternate_class (reg); | |
2056 | if (reg_class_subset_p (rclass, qty_alternate_class[qty])) | |
2057 | qty_alternate_class[qty] = rclass; | |
0f64b8f6 | 2058 | |
b1f21e0a | 2059 | if (REG_CHANGES_SIZE (reg)) |
0f64b8f6 | 2060 | qty_changes_size[qty] = 1; |
2bbd3819 RS |
2061 | } |
2062 | \f | |
2063 | /* Handle something which alters the value of an rtx REG. | |
2064 | ||
2065 | REG is whatever is set or clobbered. SETTER is the rtx that | |
2066 | is modifying the register. | |
2067 | ||
2068 | If it is not really a register, we do nothing. | |
2069 | The file-global variables `this_insn' and `this_insn_number' | |
2070 | carry info from `block_alloc'. */ | |
2071 | ||
2072 | static void | |
2073 | reg_is_set (reg, setter) | |
2074 | rtx reg; | |
2075 | rtx setter; | |
2076 | { | |
2077 | /* Note that note_stores will only pass us a SUBREG if it is a SUBREG of | |
2078 | a hard register. These may actually not exist any more. */ | |
2079 | ||
2080 | if (GET_CODE (reg) != SUBREG | |
2081 | && GET_CODE (reg) != REG) | |
2082 | return; | |
2083 | ||
2084 | /* Mark this register as being born. If it is used in a CLOBBER, mark | |
2085 | it as being born halfway between the previous insn and this insn so that | |
2086 | it conflicts with our inputs but not the outputs of the previous insn. */ | |
2087 | ||
2088 | reg_is_born (reg, 2 * this_insn_number - (GET_CODE (setter) == CLOBBER)); | |
2089 | } | |
2090 | \f | |
2091 | /* Handle beginning of the life of register REG. | |
2092 | BIRTH is the index at which this is happening. */ | |
2093 | ||
2094 | static void | |
2095 | reg_is_born (reg, birth) | |
2096 | rtx reg; | |
2097 | int birth; | |
2098 | { | |
2099 | register int regno; | |
2100 | ||
2101 | if (GET_CODE (reg) == SUBREG) | |
2102 | regno = REGNO (SUBREG_REG (reg)) + SUBREG_WORD (reg); | |
2103 | else | |
2104 | regno = REGNO (reg); | |
2105 | ||
2106 | if (regno < FIRST_PSEUDO_REGISTER) | |
2107 | { | |
2108 | mark_life (regno, GET_MODE (reg), 1); | |
2109 | ||
2110 | /* If the register was to have been born earlier that the present | |
2111 | insn, mark it as live where it is actually born. */ | |
2112 | if (birth < 2 * this_insn_number) | |
2113 | post_mark_life (regno, GET_MODE (reg), 1, birth, 2 * this_insn_number); | |
2114 | } | |
2115 | else | |
2116 | { | |
2117 | if (reg_qty[regno] == -2) | |
2118 | alloc_qty (regno, GET_MODE (reg), PSEUDO_REGNO_SIZE (regno), birth); | |
2119 | ||
2120 | /* If this register has a quantity number, show that it isn't dead. */ | |
2121 | if (reg_qty[regno] >= 0) | |
2122 | qty_death[reg_qty[regno]] = -1; | |
2123 | } | |
2124 | } | |
2125 | ||
2126 | /* Record the death of REG in the current insn. If OUTPUT_P is non-zero, | |
2127 | REG is an output that is dying (i.e., it is never used), otherwise it | |
333e0f7d RS |
2128 | is an input (the normal case). |
2129 | If OUTPUT_P is 1, then we extend the life past the end of this insn. */ | |
2bbd3819 RS |
2130 | |
2131 | static void | |
2132 | wipe_dead_reg (reg, output_p) | |
2133 | register rtx reg; | |
2134 | int output_p; | |
2135 | { | |
2136 | register int regno = REGNO (reg); | |
2137 | ||
333e0f7d RS |
2138 | /* If this insn has multiple results, |
2139 | and the dead reg is used in one of the results, | |
2140 | extend its life to after this insn, | |
2141 | so it won't get allocated together with any other result of this insn. */ | |
2142 | if (GET_CODE (PATTERN (this_insn)) == PARALLEL | |
2143 | && !single_set (this_insn)) | |
2144 | { | |
2145 | int i; | |
2146 | for (i = XVECLEN (PATTERN (this_insn), 0) - 1; i >= 0; i--) | |
2147 | { | |
2148 | rtx set = XVECEXP (PATTERN (this_insn), 0, i); | |
2149 | if (GET_CODE (set) == SET | |
2150 | && GET_CODE (SET_DEST (set)) != REG | |
2151 | && !rtx_equal_p (reg, SET_DEST (set)) | |
2152 | && reg_overlap_mentioned_p (reg, SET_DEST (set))) | |
2153 | output_p = 1; | |
2154 | } | |
2155 | } | |
2156 | ||
c182df0b RK |
2157 | /* If this register is used in an auto-increment address, then extend its |
2158 | life to after this insn, so that it won't get allocated together with | |
2159 | the result of this insn. */ | |
2160 | if (! output_p && find_regno_note (this_insn, REG_INC, regno)) | |
2161 | output_p = 1; | |
2162 | ||
2bbd3819 RS |
2163 | if (regno < FIRST_PSEUDO_REGISTER) |
2164 | { | |
2165 | mark_life (regno, GET_MODE (reg), 0); | |
2166 | ||
2167 | /* If a hard register is dying as an output, mark it as in use at | |
2168 | the beginning of this insn (the above statement would cause this | |
2169 | not to happen). */ | |
2170 | if (output_p) | |
2171 | post_mark_life (regno, GET_MODE (reg), 1, | |
2172 | 2 * this_insn_number, 2 * this_insn_number+ 1); | |
2173 | } | |
2174 | ||
2175 | else if (reg_qty[regno] >= 0) | |
2176 | qty_death[reg_qty[regno]] = 2 * this_insn_number + output_p; | |
2177 | } | |
2178 | \f | |
2179 | /* Find a block of SIZE words of hard regs in reg_class CLASS | |
2180 | that can hold something of machine-mode MODE | |
2181 | (but actually we test only the first of the block for holding MODE) | |
2182 | and still free between insn BORN_INDEX and insn DEAD_INDEX, | |
2183 | and return the number of the first of them. | |
2184 | Return -1 if such a block cannot be found. | |
2185 | If QTY crosses calls, insist on a register preserved by calls, | |
2186 | unless ACCEPT_CALL_CLOBBERED is nonzero. | |
2187 | ||
2188 | If JUST_TRY_SUGGESTED is non-zero, only try to see if the suggested | |
2189 | register is available. If not, return -1. */ | |
2190 | ||
2191 | static int | |
2192 | find_free_reg (class, mode, qty, accept_call_clobbered, just_try_suggested, | |
2193 | born_index, dead_index) | |
2194 | enum reg_class class; | |
2195 | enum machine_mode mode; | |
82c68a78 | 2196 | int qty; |
2bbd3819 RS |
2197 | int accept_call_clobbered; |
2198 | int just_try_suggested; | |
2bbd3819 RS |
2199 | int born_index, dead_index; |
2200 | { | |
2201 | register int i, ins; | |
2202 | #ifdef HARD_REG_SET | |
2203 | register /* Declare it register if it's a scalar. */ | |
2204 | #endif | |
2205 | HARD_REG_SET used, first_used; | |
2206 | #ifdef ELIMINABLE_REGS | |
2207 | static struct {int from, to; } eliminables[] = ELIMINABLE_REGS; | |
2208 | #endif | |
2209 | ||
2210 | /* Validate our parameters. */ | |
2211 | if (born_index < 0 || born_index > dead_index) | |
2212 | abort (); | |
2213 | ||
2214 | /* Don't let a pseudo live in a reg across a function call | |
2215 | if we might get a nonlocal goto. */ | |
2216 | if (current_function_has_nonlocal_label | |
2217 | && qty_n_calls_crossed[qty] > 0) | |
2218 | return -1; | |
2219 | ||
2220 | if (accept_call_clobbered) | |
2221 | COPY_HARD_REG_SET (used, call_fixed_reg_set); | |
2222 | else if (qty_n_calls_crossed[qty] == 0) | |
2223 | COPY_HARD_REG_SET (used, fixed_reg_set); | |
2224 | else | |
2225 | COPY_HARD_REG_SET (used, call_used_reg_set); | |
2226 | ||
6cad67d2 | 2227 | if (accept_call_clobbered) |
c09be6c4 | 2228 | IOR_HARD_REG_SET (used, losing_caller_save_reg_set); |
6cad67d2 | 2229 | |
2bbd3819 RS |
2230 | for (ins = born_index; ins < dead_index; ins++) |
2231 | IOR_HARD_REG_SET (used, regs_live_at[ins]); | |
2232 | ||
2233 | IOR_COMPL_HARD_REG_SET (used, reg_class_contents[(int) class]); | |
2234 | ||
2235 | /* Don't use the frame pointer reg in local-alloc even if | |
2236 | we may omit the frame pointer, because if we do that and then we | |
2237 | need a frame pointer, reload won't know how to move the pseudo | |
2238 | to another hard reg. It can move only regs made by global-alloc. | |
2239 | ||
2240 | This is true of any register that can be eliminated. */ | |
2241 | #ifdef ELIMINABLE_REGS | |
2242 | for (i = 0; i < sizeof eliminables / sizeof eliminables[0]; i++) | |
2243 | SET_HARD_REG_BIT (used, eliminables[i].from); | |
c2618f05 DE |
2244 | #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM |
2245 | /* If FRAME_POINTER_REGNUM is not a real register, then protect the one | |
0f41302f | 2246 | that it might be eliminated into. */ |
c2618f05 DE |
2247 | SET_HARD_REG_BIT (used, HARD_FRAME_POINTER_REGNUM); |
2248 | #endif | |
2bbd3819 RS |
2249 | #else |
2250 | SET_HARD_REG_BIT (used, FRAME_POINTER_REGNUM); | |
2251 | #endif | |
2252 | ||
0f64b8f6 RK |
2253 | #ifdef CLASS_CANNOT_CHANGE_SIZE |
2254 | if (qty_changes_size[qty]) | |
899d4140 | 2255 | IOR_HARD_REG_SET (used, |
0f64b8f6 RK |
2256 | reg_class_contents[(int) CLASS_CANNOT_CHANGE_SIZE]); |
2257 | #endif | |
2258 | ||
2bbd3819 RS |
2259 | /* Normally, the registers that can be used for the first register in |
2260 | a multi-register quantity are the same as those that can be used for | |
2261 | subsequent registers. However, if just trying suggested registers, | |
2262 | restrict our consideration to them. If there are copy-suggested | |
2263 | register, try them. Otherwise, try the arithmetic-suggested | |
2264 | registers. */ | |
2265 | COPY_HARD_REG_SET (first_used, used); | |
2266 | ||
2267 | if (just_try_suggested) | |
2268 | { | |
51b86d8b | 2269 | if (qty_phys_num_copy_sugg[qty] != 0) |
2bbd3819 RS |
2270 | IOR_COMPL_HARD_REG_SET (first_used, qty_phys_copy_sugg[qty]); |
2271 | else | |
2272 | IOR_COMPL_HARD_REG_SET (first_used, qty_phys_sugg[qty]); | |
2273 | } | |
2274 | ||
2275 | /* If all registers are excluded, we can't do anything. */ | |
2276 | GO_IF_HARD_REG_SUBSET (reg_class_contents[(int) ALL_REGS], first_used, fail); | |
2277 | ||
2278 | /* If at least one would be suitable, test each hard reg. */ | |
2279 | ||
2280 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
2281 | { | |
2282 | #ifdef REG_ALLOC_ORDER | |
2283 | int regno = reg_alloc_order[i]; | |
2284 | #else | |
2285 | int regno = i; | |
2286 | #endif | |
2287 | if (! TEST_HARD_REG_BIT (first_used, regno) | |
2288 | && HARD_REGNO_MODE_OK (regno, mode)) | |
2289 | { | |
2290 | register int j; | |
2291 | register int size1 = HARD_REGNO_NREGS (regno, mode); | |
2292 | for (j = 1; j < size1 && ! TEST_HARD_REG_BIT (used, regno + j); j++); | |
2293 | if (j == size1) | |
2294 | { | |
2295 | /* Mark that this register is in use between its birth and death | |
2296 | insns. */ | |
2297 | post_mark_life (regno, mode, 1, born_index, dead_index); | |
2298 | return regno; | |
2299 | } | |
2300 | #ifndef REG_ALLOC_ORDER | |
2301 | i += j; /* Skip starting points we know will lose */ | |
2302 | #endif | |
2303 | } | |
2304 | } | |
2305 | ||
2306 | fail: | |
2307 | ||
2308 | /* If we are just trying suggested register, we have just tried copy- | |
2309 | suggested registers, and there are arithmetic-suggested registers, | |
2310 | try them. */ | |
2311 | ||
2312 | /* If it would be profitable to allocate a call-clobbered register | |
2313 | and save and restore it around calls, do that. */ | |
51b86d8b RK |
2314 | if (just_try_suggested && qty_phys_num_copy_sugg[qty] != 0 |
2315 | && qty_phys_num_sugg[qty] != 0) | |
2bbd3819 RS |
2316 | { |
2317 | /* Don't try the copy-suggested regs again. */ | |
51b86d8b | 2318 | qty_phys_num_copy_sugg[qty] = 0; |
2bbd3819 RS |
2319 | return find_free_reg (class, mode, qty, accept_call_clobbered, 1, |
2320 | born_index, dead_index); | |
2321 | } | |
2322 | ||
e19f5192 RK |
2323 | /* We need not check to see if the current function has nonlocal |
2324 | labels because we don't put any pseudos that are live over calls in | |
2325 | registers in that case. */ | |
2326 | ||
2bbd3819 RS |
2327 | if (! accept_call_clobbered |
2328 | && flag_caller_saves | |
2329 | && ! just_try_suggested | |
2330 | && qty_n_calls_crossed[qty] != 0 | |
2331 | && CALLER_SAVE_PROFITABLE (qty_n_refs[qty], qty_n_calls_crossed[qty])) | |
2332 | { | |
2333 | i = find_free_reg (class, mode, qty, 1, 0, born_index, dead_index); | |
2334 | if (i >= 0) | |
2335 | caller_save_needed = 1; | |
2336 | return i; | |
2337 | } | |
2338 | return -1; | |
2339 | } | |
2340 | \f | |
2341 | /* Mark that REGNO with machine-mode MODE is live starting from the current | |
2342 | insn (if LIFE is non-zero) or dead starting at the current insn (if LIFE | |
2343 | is zero). */ | |
2344 | ||
2345 | static void | |
2346 | mark_life (regno, mode, life) | |
2347 | register int regno; | |
2348 | enum machine_mode mode; | |
2349 | int life; | |
2350 | { | |
2351 | register int j = HARD_REGNO_NREGS (regno, mode); | |
2352 | if (life) | |
2353 | while (--j >= 0) | |
2354 | SET_HARD_REG_BIT (regs_live, regno + j); | |
2355 | else | |
2356 | while (--j >= 0) | |
2357 | CLEAR_HARD_REG_BIT (regs_live, regno + j); | |
2358 | } | |
2359 | ||
2360 | /* Mark register number REGNO (with machine-mode MODE) as live (if LIFE | |
2361 | is non-zero) or dead (if LIFE is zero) from insn number BIRTH (inclusive) | |
2362 | to insn number DEATH (exclusive). */ | |
2363 | ||
2364 | static void | |
2365 | post_mark_life (regno, mode, life, birth, death) | |
82c68a78 | 2366 | int regno; |
2bbd3819 | 2367 | enum machine_mode mode; |
82c68a78 | 2368 | int life, birth, death; |
2bbd3819 RS |
2369 | { |
2370 | register int j = HARD_REGNO_NREGS (regno, mode); | |
2371 | #ifdef HARD_REG_SET | |
2372 | register /* Declare it register if it's a scalar. */ | |
2373 | #endif | |
2374 | HARD_REG_SET this_reg; | |
2375 | ||
2376 | CLEAR_HARD_REG_SET (this_reg); | |
2377 | while (--j >= 0) | |
2378 | SET_HARD_REG_BIT (this_reg, regno + j); | |
2379 | ||
2380 | if (life) | |
2381 | while (birth < death) | |
2382 | { | |
2383 | IOR_HARD_REG_SET (regs_live_at[birth], this_reg); | |
2384 | birth++; | |
2385 | } | |
2386 | else | |
2387 | while (birth < death) | |
2388 | { | |
2389 | AND_COMPL_HARD_REG_SET (regs_live_at[birth], this_reg); | |
2390 | birth++; | |
2391 | } | |
2392 | } | |
2393 | \f | |
2394 | /* INSN is the CLOBBER insn that starts a REG_NO_NOCONFLICT block, R0 | |
2395 | is the register being clobbered, and R1 is a register being used in | |
2396 | the equivalent expression. | |
2397 | ||
2398 | If R1 dies in the block and has a REG_NO_CONFLICT note on every insn | |
2399 | in which it is used, return 1. | |
2400 | ||
2401 | Otherwise, return 0. */ | |
2402 | ||
2403 | static int | |
2404 | no_conflict_p (insn, r0, r1) | |
2405 | rtx insn, r0, r1; | |
2406 | { | |
2407 | int ok = 0; | |
b1ec3c92 | 2408 | rtx note = find_reg_note (insn, REG_LIBCALL, NULL_RTX); |
2bbd3819 RS |
2409 | rtx p, last; |
2410 | ||
2411 | /* If R1 is a hard register, return 0 since we handle this case | |
2412 | when we scan the insns that actually use it. */ | |
2413 | ||
2414 | if (note == 0 | |
2415 | || (GET_CODE (r1) == REG && REGNO (r1) < FIRST_PSEUDO_REGISTER) | |
2416 | || (GET_CODE (r1) == SUBREG && GET_CODE (SUBREG_REG (r1)) == REG | |
2417 | && REGNO (SUBREG_REG (r1)) < FIRST_PSEUDO_REGISTER)) | |
2418 | return 0; | |
2419 | ||
2420 | last = XEXP (note, 0); | |
2421 | ||
2422 | for (p = NEXT_INSN (insn); p && p != last; p = NEXT_INSN (p)) | |
2423 | if (GET_RTX_CLASS (GET_CODE (p)) == 'i') | |
2424 | { | |
2425 | if (find_reg_note (p, REG_DEAD, r1)) | |
2426 | ok = 1; | |
2427 | ||
8bb19658 JW |
2428 | /* There must be a REG_NO_CONFLICT note on every insn, otherwise |
2429 | some earlier optimization pass has inserted instructions into | |
2430 | the sequence, and it is not safe to perform this optimization. | |
2431 | Note that emit_no_conflict_block always ensures that this is | |
2432 | true when these sequences are created. */ | |
2433 | if (! find_reg_note (p, REG_NO_CONFLICT, r1)) | |
2bbd3819 RS |
2434 | return 0; |
2435 | } | |
2436 | ||
2437 | return ok; | |
2438 | } | |
2439 | \f | |
7fe4336e RK |
2440 | #ifdef REGISTER_CONSTRAINTS |
2441 | ||
3061cc54 RK |
2442 | /* Return the number of alternatives for which the constraint string P |
2443 | indicates that the operand must be equal to operand 0 and that no register | |
2444 | is acceptable. */ | |
2bbd3819 RS |
2445 | |
2446 | static int | |
3061cc54 | 2447 | requires_inout (p) |
2bbd3819 RS |
2448 | char *p; |
2449 | { | |
2450 | char c; | |
2451 | int found_zero = 0; | |
3061cc54 RK |
2452 | int reg_allowed = 0; |
2453 | int num_matching_alts = 0; | |
2bbd3819 RS |
2454 | |
2455 | while (c = *p++) | |
2456 | switch (c) | |
2457 | { | |
2bbd3819 RS |
2458 | case '=': case '+': case '?': |
2459 | case '#': case '&': case '!': | |
3061cc54 | 2460 | case '*': case '%': |
2bbd3819 RS |
2461 | case '1': case '2': case '3': case '4': |
2462 | case 'm': case '<': case '>': case 'V': case 'o': | |
2463 | case 'E': case 'F': case 'G': case 'H': | |
2464 | case 's': case 'i': case 'n': | |
2465 | case 'I': case 'J': case 'K': case 'L': | |
2466 | case 'M': case 'N': case 'O': case 'P': | |
2467 | #ifdef EXTRA_CONSTRAINT | |
2468 | case 'Q': case 'R': case 'S': case 'T': case 'U': | |
2469 | #endif | |
2470 | case 'X': | |
2471 | /* These don't say anything we care about. */ | |
2472 | break; | |
2473 | ||
3061cc54 RK |
2474 | case ',': |
2475 | if (found_zero && ! reg_allowed) | |
2476 | num_matching_alts++; | |
2477 | ||
2478 | found_zero = reg_allowed = 0; | |
2479 | break; | |
2480 | ||
2481 | case '0': | |
2482 | found_zero = 1; | |
2483 | break; | |
2484 | ||
2bbd3819 RS |
2485 | case 'p': |
2486 | case 'g': case 'r': | |
2487 | default: | |
3061cc54 RK |
2488 | reg_allowed = 1; |
2489 | break; | |
2bbd3819 RS |
2490 | } |
2491 | ||
3061cc54 RK |
2492 | if (found_zero && ! reg_allowed) |
2493 | num_matching_alts++; | |
2494 | ||
2495 | return num_matching_alts; | |
2bbd3819 | 2496 | } |
7fe4336e | 2497 | #endif /* REGISTER_CONSTRAINTS */ |
2bbd3819 RS |
2498 | \f |
2499 | void | |
2500 | dump_local_alloc (file) | |
2501 | FILE *file; | |
2502 | { | |
2503 | register int i; | |
2504 | for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++) | |
2505 | if (reg_renumber[i] != -1) | |
2506 | fprintf (file, ";; Register %d in %d.\n", i, reg_renumber[i]); | |
2507 | } |