c4c75ca541370dc030f073623cb6761dd744340c
[gcc.git] / gcc / config / i860 / i860.c
1 /* Subroutines for insn-output.c for Intel 860
2 Copyright (C) 1989, 1991 Free Software Foundation, Inc.
3 Derived from sparc.c.
4
5 Written by Richard Stallman (rms@ai.mit.edu).
6
7 Hacked substantially by Ron Guilmette (rfg@ncd.com) to cater
8 to the whims of the System V Release 4 assembler.
9
10 This file is part of GNU CC.
11
12 GNU CC is free software; you can redistribute it and/or modify
13 it under the terms of the GNU General Public License as published by
14 the Free Software Foundation; either version 2, or (at your option)
15 any later version.
16
17 GNU CC is distributed in the hope that it will be useful,
18 but WITHOUT ANY WARRANTY; without even the implied warranty of
19 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 GNU General Public License for more details.
21
22 You should have received a copy of the GNU General Public License
23 along with GNU CC; see the file COPYING. If not, write to
24 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
25
26
27 #include "config.h"
28 #include "flags.h"
29 #include "rtl.h"
30 #include "regs.h"
31 #include "hard-reg-set.h"
32 #include "real.h"
33 #include "insn-config.h"
34 #include "conditions.h"
35 #include "insn-flags.h"
36 #include "output.h"
37 #include "recog.h"
38 #include "insn-attr.h"
39
40 #include <stdio.h>
41
42 static rtx find_addr_reg ();
43
44 #ifndef I860_REG_PREFIX
45 #define I860_REG_PREFIX ""
46 #endif
47
48 char *i860_reg_prefix = I860_REG_PREFIX;
49
50 /* Save information from a "cmpxx" operation until the branch is emitted. */
51
52 rtx i860_compare_op0, i860_compare_op1;
53 \f
54 /* Return non-zero if this pattern, can be evaluated safely, even if it
55 was not asked for. */
56 int
57 safe_insn_src_p (op, mode)
58 rtx op;
59 enum machine_mode mode;
60 {
61 /* Just experimenting. */
62
63 /* No floating point src is safe if it contains an arithmetic
64 operation, since that operation may trap. */
65 switch (GET_CODE (op))
66 {
67 case CONST_INT:
68 case LABEL_REF:
69 case SYMBOL_REF:
70 case CONST:
71 return 1;
72
73 case REG:
74 return 1;
75
76 case MEM:
77 return CONSTANT_ADDRESS_P (XEXP (op, 0));
78
79 /* We never need to negate or complement constants. */
80 case NEG:
81 return (mode != SFmode && mode != DFmode);
82 case NOT:
83 case ZERO_EXTEND:
84 return 1;
85
86 case EQ:
87 case NE:
88 case LT:
89 case GT:
90 case LE:
91 case GE:
92 case LTU:
93 case GTU:
94 case LEU:
95 case GEU:
96 case MINUS:
97 case PLUS:
98 return (mode != SFmode && mode != DFmode);
99 case AND:
100 case IOR:
101 case XOR:
102 case LSHIFT:
103 case ASHIFT:
104 case ASHIFTRT:
105 case LSHIFTRT:
106 if ((GET_CODE (XEXP (op, 0)) == CONST_INT && ! SMALL_INT (XEXP (op, 0)))
107 || (GET_CODE (XEXP (op, 1)) == CONST_INT && ! SMALL_INT (XEXP (op, 1))))
108 return 0;
109 return 1;
110
111 default:
112 return 0;
113 }
114 }
115
116 /* Return 1 if REG is clobbered in IN.
117 Return 2 if REG is used in IN.
118 Return 3 if REG is both used and clobbered in IN.
119 Return 0 if neither. */
120
121 static int
122 reg_clobbered_p (reg, in)
123 rtx reg;
124 rtx in;
125 {
126 register enum rtx_code code;
127
128 if (in == 0)
129 return 0;
130
131 code = GET_CODE (in);
132
133 if (code == SET || code == CLOBBER)
134 {
135 rtx dest = SET_DEST (in);
136 int set = 0;
137 int used = 0;
138
139 while (GET_CODE (dest) == STRICT_LOW_PART
140 || GET_CODE (dest) == SUBREG
141 || GET_CODE (dest) == SIGN_EXTRACT
142 || GET_CODE (dest) == ZERO_EXTRACT)
143 dest = XEXP (dest, 0);
144
145 if (dest == reg)
146 set = 1;
147 else if (GET_CODE (dest) == REG
148 && refers_to_regno_p (REGNO (reg),
149 REGNO (reg) + HARD_REGNO_NREGS (reg, GET_MODE (reg)),
150 SET_DEST (in), 0))
151 {
152 set = 1;
153 /* Anything that sets just part of the register
154 is considered using as well as setting it.
155 But note that a straight SUBREG of a single-word value
156 clobbers the entire value. */
157 if (dest != SET_DEST (in)
158 && ! (GET_CODE (SET_DEST (in)) == SUBREG
159 || UNITS_PER_WORD >= GET_MODE_SIZE (GET_MODE (dest))))
160 used = 1;
161 }
162
163 if (code == SET)
164 {
165 if (set)
166 used = refers_to_regno_p (REGNO (reg),
167 REGNO (reg) + HARD_REGNO_NREGS (reg, GET_MODE (reg)),
168 SET_SRC (in), 0);
169 else
170 used = refers_to_regno_p (REGNO (reg),
171 REGNO (reg) + HARD_REGNO_NREGS (reg, GET_MODE (reg)),
172 in, 0);
173 }
174
175 return set + used * 2;
176 }
177
178 if (refers_to_regno_p (REGNO (reg),
179 REGNO (reg) + HARD_REGNO_NREGS (reg, GET_MODE (reg)),
180 in, 0))
181 return 2;
182 return 0;
183 }
184
185 /* Return non-zero if OP can be written to without screwing up
186 GCC's model of what's going on. It is assumed that this operand
187 appears in the dest position of a SET insn in a conditional
188 branch's delay slot. AFTER is the label to start looking from. */
189 int
190 operand_clobbered_before_used_after (op, after)
191 rtx op;
192 rtx after;
193 {
194 /* Just experimenting. */
195 if (GET_CODE (op) == CC0)
196 return 1;
197 if (GET_CODE (op) == REG)
198 {
199 rtx insn;
200
201 if (op == stack_pointer_rtx)
202 return 0;
203
204 /* Scan forward from the label, to see if the value of OP
205 is clobbered before the first use. */
206
207 for (insn = NEXT_INSN (after); insn; insn = NEXT_INSN (insn))
208 {
209 if (GET_CODE (insn) == NOTE)
210 continue;
211 if (GET_CODE (insn) == INSN
212 || GET_CODE (insn) == JUMP_INSN
213 || GET_CODE (insn) == CALL_INSN)
214 {
215 switch (reg_clobbered_p (op, PATTERN (insn)))
216 {
217 default:
218 return 0;
219 case 1:
220 return 1;
221 case 0:
222 break;
223 }
224 }
225 /* If we reach another label without clobbering OP,
226 then we cannot safely write it here. */
227 else if (GET_CODE (insn) == CODE_LABEL)
228 return 0;
229 if (GET_CODE (insn) == JUMP_INSN)
230 {
231 if (condjump_p (insn))
232 return 0;
233 /* This is a jump insn which has already
234 been mangled. We can't tell what it does. */
235 if (GET_CODE (PATTERN (insn)) == PARALLEL)
236 return 0;
237 if (! JUMP_LABEL (insn))
238 return 0;
239 /* Keep following jumps. */
240 insn = JUMP_LABEL (insn);
241 }
242 }
243 return 1;
244 }
245
246 /* In both of these cases, the first insn executed
247 for this op will be a orh whatever%h,%?r0,%?r31,
248 which is tolerable. */
249 if (GET_CODE (op) == MEM)
250 return (CONSTANT_ADDRESS_P (XEXP (op, 0)));
251
252 return 0;
253 }
254
255 /* Return non-zero if this pattern, as a source to a "SET",
256 is known to yield an instruction of unit size. */
257 int
258 single_insn_src_p (op, mode)
259 rtx op;
260 enum machine_mode mode;
261 {
262 switch (GET_CODE (op))
263 {
264 case CONST_INT:
265 /* This is not always a single insn src, technically,
266 but output_delayed_branch knows how to deal with it. */
267 return 1;
268
269 case SYMBOL_REF:
270 case CONST:
271 /* This is not a single insn src, technically,
272 but output_delayed_branch knows how to deal with it. */
273 return 1;
274
275 case REG:
276 return 1;
277
278 case MEM:
279 return 1;
280
281 /* We never need to negate or complement constants. */
282 case NEG:
283 return (mode != DFmode);
284 case NOT:
285 case ZERO_EXTEND:
286 return 1;
287
288 case PLUS:
289 case MINUS:
290 /* Detect cases that require multiple instructions. */
291 if (CONSTANT_P (XEXP (op, 1))
292 && !(GET_CODE (XEXP (op, 1)) == CONST_INT
293 && SMALL_INT (XEXP (op, 1))))
294 return 0;
295 case EQ:
296 case NE:
297 case LT:
298 case GT:
299 case LE:
300 case GE:
301 case LTU:
302 case GTU:
303 case LEU:
304 case GEU:
305 /* Not doing floating point, since they probably
306 take longer than the branch slot they might fill. */
307 return (mode != SFmode && mode != DFmode);
308
309 case AND:
310 if (GET_CODE (XEXP (op, 1)) == NOT)
311 {
312 rtx arg = XEXP (XEXP (op, 1), 0);
313 if (CONSTANT_P (arg)
314 && !(GET_CODE (arg) == CONST_INT
315 && (SMALL_INT (arg)
316 || INTVAL (arg) & 0xffff == 0)))
317 return 0;
318 }
319 case IOR:
320 case XOR:
321 /* Both small and round numbers take one instruction;
322 others take two. */
323 if (CONSTANT_P (XEXP (op, 1))
324 && !(GET_CODE (XEXP (op, 1)) == CONST_INT
325 && (SMALL_INT (XEXP (op, 1))
326 || INTVAL (XEXP (op, 1)) & 0xffff == 0)))
327 return 0;
328
329 case LSHIFT:
330 case ASHIFT:
331 case ASHIFTRT:
332 case LSHIFTRT:
333 return 1;
334
335 case SUBREG:
336 if (SUBREG_WORD (op) != 0)
337 return 0;
338 return single_insn_src_p (SUBREG_REG (op), mode);
339
340 /* Not doing floating point, since they probably
341 take longer than the branch slot they might fill. */
342 case FLOAT_EXTEND:
343 case FLOAT_TRUNCATE:
344 case FLOAT:
345 case FIX:
346 case UNSIGNED_FLOAT:
347 case UNSIGNED_FIX:
348 return 0;
349
350 default:
351 return 0;
352 }
353 }
354
355 /* Nonzero only if this *really* is a single insn operand. */
356 int
357 strict_single_insn_op_p (op, mode)
358 rtx op;
359 enum machine_mode mode;
360 {
361 if (mode == VOIDmode)
362 mode = GET_MODE (op);
363
364 switch (GET_CODE (op))
365 {
366 case CC0:
367 return 1;
368
369 case CONST_INT:
370 if (SMALL_INT (op))
371 return 1;
372 /* We can put this set insn into delay slot, because this is one
373 insn; `orh'. */
374 if ((INTVAL (op) & 0xffff) == 0)
375 return 1;
376 return 0;
377
378 case SYMBOL_REF:
379 return 0;
380
381 case REG:
382 #if 0
383 /* This loses when moving an freg to a general reg. */
384 return HARD_REGNO_NREGS (REGNO (op), mode) == 1;
385 #endif
386 return (mode != DFmode && mode != DImode);
387
388 case MEM:
389 if (! CONSTANT_ADDRESS_P (XEXP (op, 0)))
390 return (mode != DFmode && mode != DImode);
391 return 0;
392
393 /* We never need to negate or complement constants. */
394 case NEG:
395 return (mode != DFmode);
396 case NOT:
397 case ZERO_EXTEND:
398 return 1;
399
400 case PLUS:
401 case MINUS:
402 /* Detect cases that require multiple instructions. */
403 if (CONSTANT_P (XEXP (op, 1))
404 && !(GET_CODE (XEXP (op, 1)) == CONST_INT
405 && SMALL_INT (XEXP (op, 1))))
406 return 0;
407 case EQ:
408 case NE:
409 case LT:
410 case GT:
411 case LE:
412 case GE:
413 case LTU:
414 case GTU:
415 case LEU:
416 case GEU:
417 return 1;
418
419 case AND:
420 if (GET_CODE (XEXP (op, 1)) == NOT)
421 {
422 rtx arg = XEXP (XEXP (op, 1), 0);
423 if (CONSTANT_P (arg)
424 && !(GET_CODE (arg) == CONST_INT
425 && (SMALL_INT (arg)
426 || INTVAL (arg) & 0xffff == 0)))
427 return 0;
428 }
429 case IOR:
430 case XOR:
431 /* Both small and round numbers take one instruction;
432 others take two. */
433 if (CONSTANT_P (XEXP (op, 1))
434 && !(GET_CODE (XEXP (op, 1)) == CONST_INT
435 && (SMALL_INT (XEXP (op, 1))
436 || INTVAL (XEXP (op, 1)) & 0xffff == 0)))
437 return 0;
438
439 case LSHIFT:
440 case ASHIFT:
441 case ASHIFTRT:
442 case LSHIFTRT:
443 return 1;
444
445 case SUBREG:
446 if (SUBREG_WORD (op) != 0)
447 return 0;
448 return strict_single_insn_op_p (SUBREG_REG (op), mode);
449
450 case SIGN_EXTEND:
451 if (GET_CODE (XEXP (op, 0)) == MEM
452 && ! CONSTANT_ADDRESS_P (XEXP (XEXP (op, 0), 0)))
453 return 1;
454 return 0;
455
456 /* Not doing floating point, since they probably
457 take longer than the branch slot they might fill. */
458 case FLOAT_EXTEND:
459 case FLOAT_TRUNCATE:
460 case FLOAT:
461 case FIX:
462 case UNSIGNED_FLOAT:
463 case UNSIGNED_FIX:
464 return 0;
465
466 default:
467 return 0;
468 }
469 }
470 \f
471 /* Return truth value of whether OP is a relational operator. */
472 int
473 relop (op, mode)
474 rtx op;
475 enum machine_mode mode;
476 {
477 switch (GET_CODE (op))
478 {
479 case EQ:
480 case NE:
481 case GT:
482 case GE:
483 case LT:
484 case LE:
485 case GTU:
486 case GEU:
487 case LTU:
488 case LEU:
489 return 1;
490 }
491 return 0;
492 }
493 \f
494 /* Return non-zero only if OP is a register of mode MODE,
495 or const0_rtx. */
496 int
497 reg_or_0_operand (op, mode)
498 rtx op;
499 enum machine_mode mode;
500 {
501 return (op == const0_rtx || register_operand (op, mode)
502 || op == CONST0_RTX (mode));
503 }
504
505 /* Return truth value of whether OP can be used as an operands in a three
506 address add/subtract insn (such as add %o1,7,%l2) of mode MODE. */
507
508 int
509 arith_operand (op, mode)
510 rtx op;
511 enum machine_mode mode;
512 {
513 return (register_operand (op, mode)
514 || (GET_CODE (op) == CONST_INT && SMALL_INT (op)));
515 }
516
517 /* Return 1 if OP is a valid first operand for a logical insn of mode MODE. */
518
519 int
520 logic_operand (op, mode)
521 rtx op;
522 enum machine_mode mode;
523 {
524 return (register_operand (op, mode)
525 || (GET_CODE (op) == CONST_INT && LOGIC_INT (op)));
526 }
527
528 /* Return 1 if OP is a valid first operand for a shift insn of mode MODE. */
529
530 int
531 shift_operand (op, mode)
532 rtx op;
533 enum machine_mode mode;
534 {
535 return (register_operand (op, mode)
536 || (GET_CODE (op) == CONST_INT));
537 }
538
539 /* Return 1 if OP is a valid first operand for either a logical insn
540 or an add insn of mode MODE. */
541
542 int
543 compare_operand (op, mode)
544 rtx op;
545 enum machine_mode mode;
546 {
547 return (register_operand (op, mode)
548 || (GET_CODE (op) == CONST_INT && SMALL_INT (op) && LOGIC_INT (op)));
549 }
550
551 /* Return truth value of whether OP can be used as the 5-bit immediate
552 operand of a bte or btne insn. */
553
554 int
555 bte_operand (op, mode)
556 rtx op;
557 enum machine_mode mode;
558 {
559 return (register_operand (op, mode)
560 || (GET_CODE (op) == CONST_INT
561 && (unsigned) INTVAL (op) < 0x20));
562 }
563
564 /* Return 1 if OP is an indexed memory reference of mode MODE. */
565
566 int
567 indexed_operand (op, mode)
568 rtx op;
569 enum machine_mode mode;
570 {
571 return (GET_CODE (op) == MEM && GET_MODE (op) == mode
572 && GET_CODE (XEXP (op, 0)) == PLUS
573 && GET_MODE (XEXP (op, 0)) == SImode
574 && register_operand (XEXP (XEXP (op, 0), 0), SImode)
575 && register_operand (XEXP (XEXP (op, 0), 1), SImode));
576 }
577
578 /* Return 1 if OP is a suitable source operand for a load insn
579 with mode MODE. */
580
581 int
582 load_operand (op, mode)
583 rtx op;
584 enum machine_mode mode;
585 {
586 return (memory_operand (op, mode) || indexed_operand (op, mode));
587 }
588
589 /* Return truth value of whether OP is a integer which fits the
590 range constraining immediate operands in add/subtract insns. */
591
592 int
593 small_int (op, mode)
594 rtx op;
595 enum machine_mode mode;
596 {
597 return (GET_CODE (op) == CONST_INT && SMALL_INT (op));
598 }
599
600 /* Return truth value of whether OP is a integer which fits the
601 range constraining immediate operands in logic insns. */
602
603 int
604 logic_int (op, mode)
605 rtx op;
606 enum machine_mode mode;
607 {
608 return (GET_CODE (op) == CONST_INT && LOGIC_INT (op));
609 }
610 \f
611 /* Return the best assembler insn template
612 for moving operands[1] into operands[0] as a fullword. */
613
614 static char *
615 singlemove_string (operands)
616 rtx *operands;
617 {
618 if (GET_CODE (operands[0]) == MEM)
619 {
620 if (GET_CODE (operands[1]) != MEM)
621 if (CONSTANT_ADDRESS_P (XEXP (operands[0], 0)))
622 {
623 if (! ((cc_prev_status.flags & CC_KNOW_HI_R31)
624 && (cc_prev_status.flags & CC_HI_R31_ADJ)
625 && cc_prev_status.mdep == XEXP (operands[0], 0)))
626 {
627 CC_STATUS_INIT;
628 output_asm_insn ("orh %h0,%?r0,%?r31", operands);
629 }
630 cc_status.flags |= CC_KNOW_HI_R31 | CC_HI_R31_ADJ;
631 cc_status.mdep = XEXP (operands[0], 0);
632 return "st.l %r1,%L0(%?r31)";
633 }
634 else
635 return "st.l %r1,%0";
636 else
637 abort ();
638 #if 0
639 {
640 rtx xoperands[2];
641
642 cc_status.flags &= ~CC_F0_IS_0;
643 xoperands[0] = gen_rtx (REG, SFmode, 32);
644 xoperands[1] = operands[1];
645 output_asm_insn (singlemove_string (xoperands), xoperands);
646 xoperands[1] = xoperands[0];
647 xoperands[0] = operands[0];
648 output_asm_insn (singlemove_string (xoperands), xoperands);
649 return "";
650 }
651 #endif
652 }
653 if (GET_CODE (operands[1]) == MEM)
654 {
655 if (CONSTANT_ADDRESS_P (XEXP (operands[1], 0)))
656 {
657 if (! ((cc_prev_status.flags & CC_KNOW_HI_R31)
658 && (cc_prev_status.flags & CC_HI_R31_ADJ)
659 && cc_prev_status.mdep == XEXP (operands[1], 0)))
660 {
661 CC_STATUS_INIT;
662 output_asm_insn ("orh %h1,%?r0,%?r31", operands);
663 }
664 cc_status.flags |= CC_KNOW_HI_R31 | CC_HI_R31_ADJ;
665 cc_status.mdep = XEXP (operands[1], 0);
666 return "ld.l %L1(%?r31),%0";
667 }
668 return "ld.l %m1,%0";
669 }
670 if (GET_CODE (operands[1]) == CONST_INT)
671 {
672 if((INTVAL (operands[1]) & 0xffff0000) == 0)
673 return "or %L1,%?r0,%0";
674 if((INTVAL (operands[1]) & 0x0000ffff) == 0)
675 return "orh %H1,%?r0,%0";
676 if (operands[1] == const0_rtx)
677 return "mov %?r0,%0";
678 }
679 return "mov %1,%0";
680 }
681 \f
682 /* Output assembler code to perform a doubleword move insn
683 with operands OPERANDS. */
684
685 char *
686 output_move_double (operands)
687 rtx *operands;
688 {
689 enum { REGOP, OFFSOP, MEMOP, PUSHOP, POPOP, CNSTOP, RNDOP } optype0, optype1;
690 rtx latehalf[2];
691 rtx addreg0 = 0, addreg1 = 0;
692
693 /* First classify both operands. */
694
695 if (REG_P (operands[0]))
696 optype0 = REGOP;
697 else if (offsettable_memref_p (operands[0]))
698 optype0 = OFFSOP;
699 else if (GET_CODE (operands[0]) == MEM)
700 optype0 = MEMOP;
701 else
702 optype0 = RNDOP;
703
704 if (REG_P (operands[1]))
705 optype1 = REGOP;
706 else if (CONSTANT_P (operands[1]))
707 optype1 = CNSTOP;
708 else if (offsettable_memref_p (operands[1]))
709 optype1 = OFFSOP;
710 else if (GET_CODE (operands[1]) == MEM)
711 optype1 = MEMOP;
712 else
713 optype1 = RNDOP;
714
715 /* Check for the cases that the operand constraints are not
716 supposed to allow to happen. Abort if we get one,
717 because generating code for these cases is painful. */
718
719 if (optype0 == RNDOP || optype1 == RNDOP)
720 abort ();
721
722 /* If an operand is an unoffsettable memory ref, find a register
723 we can increment temporarily to make it refer to the second word. */
724
725 if (optype0 == MEMOP)
726 addreg0 = find_addr_reg (XEXP (operands[0], 0));
727
728 if (optype1 == MEMOP)
729 addreg1 = find_addr_reg (XEXP (operands[1], 0));
730
731 /* ??? Perhaps in some cases move double words
732 if there is a spare pair of floating regs. */
733
734 /* Ok, we can do one word at a time.
735 Normally we do the low-numbered word first,
736 but if either operand is autodecrementing then we
737 do the high-numbered word first.
738
739 In either case, set up in LATEHALF the operands to use
740 for the high-numbered word and in some cases alter the
741 operands in OPERANDS to be suitable for the low-numbered word. */
742
743 if (optype0 == REGOP)
744 latehalf[0] = gen_rtx (REG, SImode, REGNO (operands[0]) + 1);
745 else if (optype0 == OFFSOP)
746 latehalf[0] = adj_offsettable_operand (operands[0], 4);
747 else
748 latehalf[0] = operands[0];
749
750 if (optype1 == REGOP)
751 latehalf[1] = gen_rtx (REG, SImode, REGNO (operands[1]) + 1);
752 else if (optype1 == OFFSOP)
753 latehalf[1] = adj_offsettable_operand (operands[1], 4);
754 else if (optype1 == CNSTOP)
755 {
756 if (GET_CODE (operands[1]) == CONST_DOUBLE)
757 split_double (operands[1], &operands[1], &latehalf[1]);
758 else if (CONSTANT_P (operands[1]))
759 latehalf[1] = const0_rtx;
760 }
761 else
762 latehalf[1] = operands[1];
763
764 /* If the first move would clobber the source of the second one,
765 do them in the other order.
766
767 RMS says "This happens only for registers;
768 such overlap can't happen in memory unless the user explicitly
769 sets it up, and that is an undefined circumstance."
770
771 but it happens on the sparc when loading parameter registers,
772 so I am going to define that circumstance, and make it work
773 as expected. */
774
775 if (optype0 == REGOP && optype1 == REGOP
776 && REGNO (operands[0]) == REGNO (latehalf[1]))
777 {
778 CC_STATUS_PARTIAL_INIT;
779 /* Make any unoffsettable addresses point at high-numbered word. */
780 if (addreg0)
781 output_asm_insn ("adds 0x4,%0,%0", &addreg0);
782 if (addreg1)
783 output_asm_insn ("adds 0x4,%0,%0", &addreg1);
784
785 /* Do that word. */
786 output_asm_insn (singlemove_string (latehalf), latehalf);
787
788 /* Undo the adds we just did. */
789 if (addreg0)
790 output_asm_insn ("adds -0x4,%0,%0", &addreg0);
791 if (addreg1)
792 output_asm_insn ("adds -0x4,%0,%0", &addreg1);
793
794 /* Do low-numbered word. */
795 return singlemove_string (operands);
796 }
797 else if (optype0 == REGOP && optype1 != REGOP
798 && reg_overlap_mentioned_p (operands[0], operands[1]))
799 {
800 /* Do the late half first. */
801 output_asm_insn (singlemove_string (latehalf), latehalf);
802 /* Then clobber. */
803 return singlemove_string (operands);
804 }
805
806 /* Normal case: do the two words, low-numbered first. */
807
808 output_asm_insn (singlemove_string (operands), operands);
809
810 CC_STATUS_PARTIAL_INIT;
811 /* Make any unoffsettable addresses point at high-numbered word. */
812 if (addreg0)
813 output_asm_insn ("adds 0x4,%0,%0", &addreg0);
814 if (addreg1)
815 output_asm_insn ("adds 0x4,%0,%0", &addreg1);
816
817 /* Do that word. */
818 output_asm_insn (singlemove_string (latehalf), latehalf);
819
820 /* Undo the adds we just did. */
821 if (addreg0)
822 output_asm_insn ("adds -0x4,%0,%0", &addreg0);
823 if (addreg1)
824 output_asm_insn ("adds -0x4,%0,%0", &addreg1);
825
826 return "";
827 }
828 \f
829 char *
830 output_fp_move_double (operands)
831 rtx *operands;
832 {
833 /* If the source operand is any sort of zero, use f0 instead. */
834
835 if (operands[1] == CONST0_RTX (GET_MODE (operands[1])))
836 operands[1] = gen_rtx (REG, DFmode, F0_REGNUM);
837
838 if (FP_REG_P (operands[0]))
839 {
840 if (FP_REG_P (operands[1]))
841 return "fmov.dd %1,%0";
842 if (GET_CODE (operands[1]) == REG)
843 {
844 output_asm_insn ("ixfr %1,%0", operands);
845 operands[0] = gen_rtx (REG, VOIDmode, REGNO (operands[0]) + 1);
846 operands[1] = gen_rtx (REG, VOIDmode, REGNO (operands[1]) + 1);
847 return "ixfr %1,%0";
848 }
849 if (operands[1] == CONST0_RTX (DFmode))
850 return "fmov.dd f0,%0";
851 if (CONSTANT_ADDRESS_P (XEXP (operands[1], 0)))
852 {
853 if (! ((cc_prev_status.flags & CC_KNOW_HI_R31)
854 && (cc_prev_status.flags & CC_HI_R31_ADJ)
855 && cc_prev_status.mdep == XEXP (operands[1], 0)))
856 {
857 CC_STATUS_INIT;
858 output_asm_insn ("orh %h1,%?r0,%?r31", operands);
859 }
860 cc_status.flags |= CC_KNOW_HI_R31 | CC_HI_R31_ADJ;
861 cc_status.mdep = XEXP (operands[1], 0);
862 return "fld.d %L1(%?r31),%0";
863 }
864 return "fld.d %1,%0";
865 }
866 else if (FP_REG_P (operands[1]))
867 {
868 if (GET_CODE (operands[0]) == REG)
869 {
870 output_asm_insn ("fxfr %1,%0", operands);
871 operands[0] = gen_rtx (REG, VOIDmode, REGNO (operands[0]) + 1);
872 operands[1] = gen_rtx (REG, VOIDmode, REGNO (operands[1]) + 1);
873 return "fxfr %1,%0";
874 }
875 if (CONSTANT_ADDRESS_P (XEXP (operands[0], 0)))
876 {
877 if (! ((cc_prev_status.flags & CC_KNOW_HI_R31)
878 && (cc_prev_status.flags & CC_HI_R31_ADJ)
879 && cc_prev_status.mdep == XEXP (operands[0], 0)))
880 {
881 CC_STATUS_INIT;
882 output_asm_insn ("orh %h0,%?r0,%?r31", operands);
883 }
884 cc_status.flags |= CC_KNOW_HI_R31 | CC_HI_R31_ADJ;
885 cc_status.mdep = XEXP (operands[0], 0);
886 return "fst.d %1,%L0(%?r31)";
887 }
888 return "fst.d %1,%0";
889 }
890 else
891 abort ();
892 /* NOTREACHED */
893 return NULL;
894 }
895 \f
896 /* Return a REG that occurs in ADDR with coefficient 1.
897 ADDR can be effectively incremented by incrementing REG. */
898
899 static rtx
900 find_addr_reg (addr)
901 rtx addr;
902 {
903 while (GET_CODE (addr) == PLUS)
904 {
905 if (GET_CODE (XEXP (addr, 0)) == REG)
906 addr = XEXP (addr, 0);
907 else if (GET_CODE (XEXP (addr, 1)) == REG)
908 addr = XEXP (addr, 1);
909 else if (CONSTANT_P (XEXP (addr, 0)))
910 addr = XEXP (addr, 1);
911 else if (CONSTANT_P (XEXP (addr, 1)))
912 addr = XEXP (addr, 0);
913 else
914 abort ();
915 }
916 if (GET_CODE (addr) == REG)
917 return addr;
918 abort ();
919 /* NOTREACHED */
920 return NULL;
921 }
922
923 /* Return a template for a load instruction with mode MODE and
924 arguments from the string ARGS.
925
926 This string is in static storage. */
927
928 static char *
929 load_opcode (mode, args, reg)
930 enum machine_mode mode;
931 char *args;
932 rtx reg;
933 {
934 static char buf[30];
935 char *opcode;
936
937 switch (mode)
938 {
939 case QImode:
940 opcode = "ld.b";
941 break;
942
943 case HImode:
944 opcode = "ld.s";
945 break;
946
947 case SImode:
948 case SFmode:
949 if (FP_REG_P (reg))
950 opcode = "fld.l";
951 else
952 opcode = "ld.l";
953 break;
954
955 case DImode:
956 if (!FP_REG_P (reg))
957 abort ();
958 case DFmode:
959 opcode = "fld.d";
960 break;
961
962 default:
963 abort ();
964 }
965
966 sprintf (buf, "%s %s", opcode, args);
967 return buf;
968 }
969
970 /* Return a template for a store instruction with mode MODE and
971 arguments from the string ARGS.
972
973 This string is in static storage. */
974
975 static char *
976 store_opcode (mode, args, reg)
977 enum machine_mode mode;
978 char *args;
979 rtx reg;
980 {
981 static char buf[30];
982 char *opcode;
983
984 switch (mode)
985 {
986 case QImode:
987 opcode = "st.b";
988 break;
989
990 case HImode:
991 opcode = "st.s";
992 break;
993
994 case SImode:
995 case SFmode:
996 if (FP_REG_P (reg))
997 opcode = "fst.l";
998 else
999 opcode = "st.l";
1000 break;
1001
1002 case DImode:
1003 if (!FP_REG_P (reg))
1004 abort ();
1005 case DFmode:
1006 opcode = "fst.d";
1007 break;
1008
1009 default:
1010 abort ();
1011 }
1012
1013 sprintf (buf, "%s %s", opcode, args);
1014 return buf;
1015 }
1016 \f
1017 /* Output a store-in-memory whose operands are OPERANDS[0,1].
1018 OPERANDS[0] is a MEM, and OPERANDS[1] is a reg or zero.
1019
1020 This function returns a template for an insn.
1021 This is in static storage.
1022
1023 It may also output some insns directly.
1024 It may alter the values of operands[0] and operands[1]. */
1025
1026 char *
1027 output_store (operands)
1028 rtx *operands;
1029 {
1030 enum machine_mode mode = GET_MODE (operands[0]);
1031 rtx address = XEXP (operands[0], 0);
1032 char *string;
1033
1034 cc_status.flags |= CC_KNOW_HI_R31 | CC_HI_R31_ADJ;
1035 cc_status.mdep = address;
1036
1037 if (! ((cc_prev_status.flags & CC_KNOW_HI_R31)
1038 && (cc_prev_status.flags & CC_HI_R31_ADJ)
1039 && address == cc_prev_status.mdep))
1040 {
1041 CC_STATUS_INIT;
1042 output_asm_insn ("orh %h0,%?r0,%?r31", operands);
1043 cc_prev_status.mdep = address;
1044 }
1045
1046 /* Store zero in two parts when appropriate. */
1047 if (mode == DFmode && operands[1] == CONST0_RTX (DFmode))
1048 return store_opcode (DFmode, "%r1,%L0(%?r31)", operands[1]);
1049
1050 /* Code below isn't smart enough to move a doubleword in two parts,
1051 so use output_move_double to do that in the cases that require it. */
1052 if ((mode == DImode || mode == DFmode)
1053 && ! FP_REG_P (operands[1]))
1054 return output_move_double (operands);
1055
1056 return store_opcode (mode, "%r1,%L0(%?r31)", operands[1]);
1057 }
1058
1059 /* Output a load-from-memory whose operands are OPERANDS[0,1].
1060 OPERANDS[0] is a reg, and OPERANDS[1] is a mem.
1061
1062 This function returns a template for an insn.
1063 This is in static storage.
1064
1065 It may also output some insns directly.
1066 It may alter the values of operands[0] and operands[1]. */
1067
1068 char *
1069 output_load (operands)
1070 rtx *operands;
1071 {
1072 enum machine_mode mode = GET_MODE (operands[0]);
1073 rtx address = XEXP (operands[1], 0);
1074
1075 /* We don't bother trying to see if we know %hi(address).
1076 This is because we are doing a load, and if we know the
1077 %hi value, we probably also know that value in memory. */
1078 cc_status.flags |= CC_KNOW_HI_R31 | CC_HI_R31_ADJ;
1079 cc_status.mdep = address;
1080
1081 if (! ((cc_prev_status.flags & CC_KNOW_HI_R31)
1082 && (cc_prev_status.flags & CC_HI_R31_ADJ)
1083 && address == cc_prev_status.mdep
1084 && cc_prev_status.mdep == cc_status.mdep))
1085 {
1086 CC_STATUS_INIT;
1087 output_asm_insn ("orh %h1,%?r0,%?r31", operands);
1088 cc_prev_status.mdep = address;
1089 }
1090
1091 /* Code below isn't smart enough to move a doubleword in two parts,
1092 so use output_move_double to do that in the cases that require it. */
1093 if ((mode == DImode || mode == DFmode)
1094 && ! FP_REG_P (operands[0]))
1095 return output_move_double (operands);
1096
1097 return load_opcode (mode, "%L1(%?r31),%0", operands[0]);
1098 }
1099 \f
1100 #if 0
1101 /* Load the address specified by OPERANDS[3] into the register
1102 specified by OPERANDS[0].
1103
1104 OPERANDS[3] may be the result of a sum, hence it could either be:
1105
1106 (1) CONST
1107 (2) REG
1108 (2) REG + CONST_INT
1109 (3) REG + REG + CONST_INT
1110 (4) REG + REG (special case of 3).
1111
1112 Note that (3) is not a legitimate address.
1113 All cases are handled here. */
1114
1115 void
1116 output_load_address (operands)
1117 rtx *operands;
1118 {
1119 rtx base, offset;
1120
1121 if (CONSTANT_P (operands[3]))
1122 {
1123 output_asm_insn ("mov %3,%0", operands);
1124 return;
1125 }
1126
1127 if (REG_P (operands[3]))
1128 {
1129 if (REGNO (operands[0]) != REGNO (operands[3]))
1130 output_asm_insn ("shl %?r0,%3,%0", operands);
1131 return;
1132 }
1133
1134 if (GET_CODE (operands[3]) != PLUS)
1135 abort ();
1136
1137 base = XEXP (operands[3], 0);
1138 offset = XEXP (operands[3], 1);
1139
1140 if (GET_CODE (base) == CONST_INT)
1141 {
1142 rtx tmp = base;
1143 base = offset;
1144 offset = tmp;
1145 }
1146
1147 if (GET_CODE (offset) != CONST_INT)
1148 {
1149 /* Operand is (PLUS (REG) (REG)). */
1150 base = operands[3];
1151 offset = const0_rtx;
1152 }
1153
1154 if (REG_P (base))
1155 {
1156 operands[6] = base;
1157 operands[7] = offset;
1158 CC_STATUS_PARTIAL_INIT;
1159 if (SMALL_INT (offset))
1160 output_asm_insn ("adds %7,%6,%0", operands);
1161 else
1162 output_asm_insn ("mov %7,%0\n\tadds %0,%6,%0", operands);
1163 }
1164 else if (GET_CODE (base) == PLUS)
1165 {
1166 operands[6] = XEXP (base, 0);
1167 operands[7] = XEXP (base, 1);
1168 operands[8] = offset;
1169
1170 CC_STATUS_PARTIAL_INIT;
1171 if (SMALL_INT (offset))
1172 output_asm_insn ("adds %6,%7,%0\n\tadds %8,%0,%0", operands);
1173 else
1174 output_asm_insn ("mov %8,%0\n\tadds %0,%6,%0\n\tadds %0,%7,%0", operands);
1175 }
1176 else
1177 abort ();
1178 }
1179 #endif
1180
1181 /* Output code to place a size count SIZE in register REG.
1182 Because block moves are pipelined, we don't include the
1183 first element in the transfer of SIZE to REG.
1184 For this, we subtract ALIGN. (Actually, I think it is not
1185 right to subtract on this machine, so right now we don't.) */
1186
1187 static void
1188 output_size_for_block_move (size, reg, align)
1189 rtx size, reg, align;
1190 {
1191 rtx xoperands[3];
1192
1193 xoperands[0] = reg;
1194 xoperands[1] = size;
1195 xoperands[2] = align;
1196
1197 #if 1
1198 cc_status.flags &= ~ CC_KNOW_HI_R31;
1199 output_asm_insn ("mov %1,%0", xoperands);
1200 #else
1201 if (GET_CODE (size) == REG)
1202 output_asm_insn ("sub %2,%1,%0", xoperands);
1203 else
1204 {
1205 xoperands[1]
1206 = gen_rtx (CONST_INT, VOIDmode, INTVAL (size) - INTVAL (align));
1207 cc_status.flags &= ~ CC_KNOW_HI_R31;
1208 output_asm_insn ("mov %1,%0", xoperands);
1209 }
1210 #endif
1211 }
1212
1213 /* Emit code to perform a block move.
1214
1215 OPERANDS[0] is the destination.
1216 OPERANDS[1] is the source.
1217 OPERANDS[2] is the size.
1218 OPERANDS[3] is the known safe alignment.
1219 OPERANDS[4..6] are pseudos we can safely clobber as temps. */
1220
1221 char *
1222 output_block_move (operands)
1223 rtx *operands;
1224 {
1225 /* A vector for our computed operands. Note that load_output_address
1226 makes use of (and can clobber) up to the 8th element of this vector. */
1227 rtx xoperands[10];
1228 rtx zoperands[10];
1229 static int movstrsi_label = 0;
1230 int i, j;
1231 rtx temp1 = operands[4];
1232 rtx alignrtx = operands[3];
1233 int align = INTVAL (alignrtx);
1234 int chunk_size;
1235
1236 xoperands[0] = operands[0];
1237 xoperands[1] = operands[1];
1238 xoperands[2] = temp1;
1239
1240 /* We can't move more than four bytes at a time
1241 because we have only one register to move them through. */
1242 if (align > 4)
1243 {
1244 align = 4;
1245 alignrtx = gen_rtx (CONST_INT, VOIDmode, 4);
1246 }
1247
1248 /* Recognize special cases of block moves. These occur
1249 when GNU C++ is forced to treat something as BLKmode
1250 to keep it in memory, when its mode could be represented
1251 with something smaller.
1252
1253 We cannot do this for global variables, since we don't know
1254 what pages they don't cross. Sigh. */
1255 if (GET_CODE (operands[2]) == CONST_INT
1256 && ! CONSTANT_ADDRESS_P (operands[0])
1257 && ! CONSTANT_ADDRESS_P (operands[1]))
1258 {
1259 int size = INTVAL (operands[2]);
1260 rtx op0 = xoperands[0];
1261 rtx op1 = xoperands[1];
1262
1263 if ((align & 3) == 0 && (size & 3) == 0 && (size >> 2) <= 16)
1264 {
1265 if (memory_address_p (SImode, plus_constant (op0, size))
1266 && memory_address_p (SImode, plus_constant (op1, size)))
1267 {
1268 cc_status.flags &= ~CC_KNOW_HI_R31;
1269 for (i = (size>>2)-1; i >= 0; i--)
1270 {
1271 xoperands[0] = plus_constant (op0, i * 4);
1272 xoperands[1] = plus_constant (op1, i * 4);
1273 output_asm_insn ("ld.l %a1,%?r31\n\tst.l %?r31,%a0",
1274 xoperands);
1275 }
1276 return "";
1277 }
1278 }
1279 else if ((align & 1) == 0 && (size & 1) == 0 && (size >> 1) <= 16)
1280 {
1281 if (memory_address_p (HImode, plus_constant (op0, size))
1282 && memory_address_p (HImode, plus_constant (op1, size)))
1283 {
1284 cc_status.flags &= ~CC_KNOW_HI_R31;
1285 for (i = (size>>1)-1; i >= 0; i--)
1286 {
1287 xoperands[0] = plus_constant (op0, i * 2);
1288 xoperands[1] = plus_constant (op1, i * 2);
1289 output_asm_insn ("ld.s %a1,%?r31\n\tst.s %?r31,%a0",
1290 xoperands);
1291 }
1292 return "";
1293 }
1294 }
1295 else if (size <= 16)
1296 {
1297 if (memory_address_p (QImode, plus_constant (op0, size))
1298 && memory_address_p (QImode, plus_constant (op1, size)))
1299 {
1300 cc_status.flags &= ~CC_KNOW_HI_R31;
1301 for (i = size-1; i >= 0; i--)
1302 {
1303 xoperands[0] = plus_constant (op0, i);
1304 xoperands[1] = plus_constant (op1, i);
1305 output_asm_insn ("ld.b %a1,%?r31\n\tst.b %?r31,%a0",
1306 xoperands);
1307 }
1308 return "";
1309 }
1310 }
1311 }
1312
1313 /* Since we clobber untold things, nix the condition codes. */
1314 CC_STATUS_INIT;
1315
1316 /* This is the size of the transfer.
1317 Either use the register which already contains the size,
1318 or use a free register (used by no operands). */
1319 output_size_for_block_move (operands[2], operands[4], alignrtx);
1320
1321 #if 0
1322 /* Also emit code to decrement the size value by ALIGN. */
1323 zoperands[0] = operands[0];
1324 zoperands[3] = plus_constant (operands[0], align);
1325 output_load_address (zoperands);
1326 #endif
1327
1328 /* Generate number for unique label. */
1329
1330 xoperands[3] = gen_rtx (CONST_INT, VOIDmode, movstrsi_label++);
1331
1332 /* Calculate the size of the chunks we will be trying to move first. */
1333
1334 #if 0
1335 if ((align & 3) == 0)
1336 chunk_size = 4;
1337 else if ((align & 1) == 0)
1338 chunk_size = 2;
1339 else
1340 #endif
1341 chunk_size = 1;
1342
1343 /* Copy the increment (negative) to a register for bla insn. */
1344
1345 xoperands[4] = gen_rtx (CONST_INT, VOIDmode, - chunk_size);
1346 xoperands[5] = operands[5];
1347 output_asm_insn ("adds %4,%?r0,%5", xoperands);
1348
1349 /* Predecrement the loop counter. This happens again also in the `bla'
1350 instruction which precceds the loop, but we need to have it done
1351 two times before we enter the loop because of the bizzare semantics
1352 of the bla instruction. */
1353
1354 output_asm_insn ("adds %5,%2,%2", xoperands);
1355
1356 /* Check for the case where the original count was less than or equal to
1357 zero. Avoid going through the loop at all if the original count was
1358 indeed less than or equal to zero. Note that we treat the count as
1359 if it were a signed 32-bit quantity here, rather than an unsigned one,
1360 even though we really shouldn't. We have to do this because of the
1361 semantics of the `ble' instruction, which assume that the count is
1362 a signed 32-bit value. Anyway, in practice it won't matter because
1363 nobody is going to try to do a memcpy() of more than half of the
1364 entire address space (i.e. 2 gigabytes) anyway. */
1365
1366 output_asm_insn ("bc .Le%3", xoperands);
1367
1368 /* Make available a register which is a temporary. */
1369
1370 xoperands[6] = operands[6];
1371
1372 /* Now the actual loop.
1373 In xoperands, elements 1 and 0 are the input and output vectors.
1374 Element 2 is the loop index. Element 5 is the increment. */
1375
1376 output_asm_insn ("subs %1,%5,%1", xoperands);
1377 output_asm_insn ("bla %5,%2,.Lm%3", xoperands);
1378 output_asm_insn ("adds %0,%2,%6", xoperands);
1379 output_asm_insn ("\n.Lm%3:", xoperands); /* Label for bla above. */
1380 output_asm_insn ("\n.Ls%3:", xoperands); /* Loop start label. */
1381 output_asm_insn ("adds %5,%6,%6", xoperands);
1382
1383 /* NOTE: The code here which is supposed to handle the cases where the
1384 sources and destinations are known to start on a 4 or 2 byte boundary
1385 are currently broken. They fail to do anything about the overflow
1386 bytes which might still need to be copied even after we have copied
1387 some number of words or halfwords. Thus, for now we use the lowest
1388 common denominator, i.e. the code which just copies some number of
1389 totally unaligned individual bytes. (See the calculation of
1390 chunk_size above. */
1391
1392 if (chunk_size == 4)
1393 {
1394 output_asm_insn ("ld.l %2(%1),%?r31", xoperands);
1395 output_asm_insn ("bla %5,%2,.Ls%3", xoperands);
1396 output_asm_insn ("st.l %?r31,8(%6)", xoperands);
1397 }
1398 else if (chunk_size == 2)
1399 {
1400 output_asm_insn ("ld.s %2(%1),%?r31", xoperands);
1401 output_asm_insn ("bla %5,%2,.Ls%3", xoperands);
1402 output_asm_insn ("st.s %?r31,4(%6)", xoperands);
1403 }
1404 else /* chunk_size == 1 */
1405 {
1406 output_asm_insn ("ld.b %2(%1),%?r31", xoperands);
1407 output_asm_insn ("bla %5,%2,.Ls%3", xoperands);
1408 output_asm_insn ("st.b %?r31,2(%6)", xoperands);
1409 }
1410 output_asm_insn ("\n.Le%3:", xoperands); /* Here if count <= 0. */
1411
1412 return "";
1413 }
1414 \f
1415 /* Output a delayed branch insn with the delay insn in its
1416 branch slot. The delayed branch insn template is in TEMPLATE,
1417 with operands OPERANDS. The insn in its delay slot is INSN.
1418
1419 As a special case, since we know that all memory transfers are via
1420 ld/st insns, if we see a (MEM (SYMBOL_REF ...)) we divide the memory
1421 reference around the branch as
1422
1423 orh ha%x,%?r0,%?r31
1424 b ...
1425 ld/st l%x(%?r31),...
1426
1427 As another special case, we handle loading (SYMBOL_REF ...) and
1428 other large constants around branches as well:
1429
1430 orh h%x,%?r0,%0
1431 b ...
1432 or l%x,%0,%1
1433
1434 */
1435
1436 char *
1437 output_delayed_branch (template, operands, insn)
1438 char *template;
1439 rtx *operands;
1440 rtx insn;
1441 {
1442 rtx src = XVECEXP (PATTERN (insn), 0, 1);
1443 rtx dest = XVECEXP (PATTERN (insn), 0, 0);
1444
1445 /* See if we are doing some branch together with setting some register
1446 to some 32-bit value which does (or may) have some of the high-order
1447 16 bits set. If so, we need to set the register in two stages. One
1448 stage must be done before the branch, and the other one can be done
1449 in the delay slot. */
1450
1451 if ( (GET_CODE (src) == CONST_INT
1452 && ((unsigned) INTVAL (src) & (unsigned) 0xffff0000) != (unsigned) 0)
1453 || (GET_CODE (src) == SYMBOL_REF)
1454 || (GET_CODE (src) == LABEL_REF)
1455 || (GET_CODE (src) == CONST))
1456 {
1457 rtx xoperands[2];
1458 xoperands[0] = dest;
1459 xoperands[1] = src;
1460
1461 CC_STATUS_PARTIAL_INIT;
1462 /* Output the `orh' insn. */
1463 output_asm_insn ("orh %H1,%?r0,%0", xoperands);
1464
1465 /* Output the branch instruction next. */
1466 output_asm_insn (template, operands);
1467
1468 /* Now output the `or' insn. */
1469 output_asm_insn ("or %L1,%0,%0", xoperands);
1470 }
1471 else if ((GET_CODE (src) == MEM
1472 && CONSTANT_ADDRESS_P (XEXP (src, 0)))
1473 || (GET_CODE (dest) == MEM
1474 && CONSTANT_ADDRESS_P (XEXP (dest, 0))))
1475 {
1476 rtx xoperands[2];
1477 char *split_template;
1478 xoperands[0] = dest;
1479 xoperands[1] = src;
1480
1481 /* Output the `orh' insn. */
1482 if (GET_CODE (src) == MEM)
1483 {
1484 if (! ((cc_prev_status.flags & CC_KNOW_HI_R31)
1485 && (cc_prev_status.flags & CC_HI_R31_ADJ)
1486 && cc_prev_status.mdep == XEXP (operands[1], 0)))
1487 {
1488 CC_STATUS_INIT;
1489 output_asm_insn ("orh %h1,%?r0,%?r31", xoperands);
1490 }
1491 split_template = load_opcode (GET_MODE (dest),
1492 "%L1(%?r31),%0", dest);
1493 }
1494 else
1495 {
1496 if (! ((cc_prev_status.flags & CC_KNOW_HI_R31)
1497 && (cc_prev_status.flags & CC_HI_R31_ADJ)
1498 && cc_prev_status.mdep == XEXP (operands[0], 0)))
1499 {
1500 CC_STATUS_INIT;
1501 output_asm_insn ("orh %h0,%?r0,%?r31", xoperands);
1502 }
1503 split_template = store_opcode (GET_MODE (dest),
1504 "%r1,%L0(%?r31)", src);
1505 }
1506
1507 /* Output the branch instruction next. */
1508 output_asm_insn (template, operands);
1509
1510 /* Now output the load or store.
1511 No need to do a CC_STATUS_INIT, because we are branching anyway. */
1512 output_asm_insn (split_template, xoperands);
1513 }
1514 else
1515 {
1516 int insn_code_number;
1517 rtx pat = gen_rtx (SET, VOIDmode, dest, src);
1518 rtx delay_insn = gen_rtx (INSN, VOIDmode, 0, 0, 0, pat, -1, 0, 0);
1519 int i;
1520
1521 /* Output the branch instruction first. */
1522 output_asm_insn (template, operands);
1523
1524 /* Now recognize the insn which we put in its delay slot.
1525 We must do this after outputing the branch insn,
1526 since operands may just be a pointer to `recog_operand'. */
1527 INSN_CODE (delay_insn) = insn_code_number = recog (pat, delay_insn);
1528 if (insn_code_number == -1)
1529 abort ();
1530
1531 for (i = 0; i < insn_n_operands[insn_code_number]; i++)
1532 {
1533 if (GET_CODE (recog_operand[i]) == SUBREG)
1534 recog_operand[i] = alter_subreg (recog_operand[i]);
1535 }
1536
1537 insn_extract (delay_insn);
1538 if (! constrain_operands (insn_code_number, 1))
1539 fatal_insn_not_found (delay_insn);
1540
1541 template = insn_template[insn_code_number];
1542 if (template == 0)
1543 template = (*insn_outfun[insn_code_number]) (recog_operand, delay_insn);
1544 output_asm_insn (template, recog_operand);
1545 }
1546 CC_STATUS_INIT;
1547 return "";
1548 }
1549
1550 /* Output a newly constructed insn DELAY_INSN. */
1551 char *
1552 output_delay_insn (delay_insn)
1553 rtx delay_insn;
1554 {
1555 char *template;
1556 int insn_code_number;
1557 int i;
1558
1559 /* Now recognize the insn which we put in its delay slot.
1560 We must do this after outputing the branch insn,
1561 since operands may just be a pointer to `recog_operand'. */
1562 insn_code_number = recog_memoized (delay_insn);
1563 if (insn_code_number == -1)
1564 abort ();
1565
1566 /* Extract the operands of this delay insn. */
1567 INSN_CODE (delay_insn) = insn_code_number;
1568 insn_extract (delay_insn);
1569
1570 /* It is possible that this insn has not been properly scaned by final
1571 yet. If this insn's operands don't appear in the peephole's
1572 actual operands, then they won't be fixed up by final, so we
1573 make sure they get fixed up here. -- This is a kludge. */
1574 for (i = 0; i < insn_n_operands[insn_code_number]; i++)
1575 {
1576 if (GET_CODE (recog_operand[i]) == SUBREG)
1577 recog_operand[i] = alter_subreg (recog_operand[i]);
1578 }
1579
1580 #ifdef REGISTER_CONSTRAINTS
1581 if (! constrain_operands (insn_code_number))
1582 abort ();
1583 #endif
1584
1585 cc_prev_status = cc_status;
1586
1587 /* Update `cc_status' for this instruction.
1588 The instruction's output routine may change it further.
1589 If the output routine for a jump insn needs to depend
1590 on the cc status, it should look at cc_prev_status. */
1591
1592 NOTICE_UPDATE_CC (PATTERN (delay_insn), delay_insn);
1593
1594 /* Now get the template for what this insn would
1595 have been, without the branch. */
1596
1597 template = insn_template[insn_code_number];
1598 if (template == 0)
1599 template = (*insn_outfun[insn_code_number]) (recog_operand, delay_insn);
1600 output_asm_insn (template, recog_operand);
1601 return "";
1602 }
1603 \f
1604 /* Special routine to convert an SFmode value represented as a
1605 CONST_DOUBLE into its equivalent unsigned long bit pattern.
1606 We convert the value from a double precision floating-point
1607 value to single precision first, and thence to a bit-wise
1608 equivalent unsigned long value. This routine is used when
1609 generating an immediate move of an SFmode value directly
1610 into a general register because the svr4 assembler doesn't
1611 grok floating literals in instruction operand contexts. */
1612
1613 unsigned long
1614 sfmode_constant_to_ulong (x)
1615 rtx x;
1616 {
1617 REAL_VALUE_TYPE d;
1618 union { float f; unsigned long i; } u2;
1619
1620 if (GET_CODE (x) != CONST_DOUBLE || GET_MODE (x) != SFmode)
1621 abort ();
1622
1623 #if TARGET_FLOAT_FORMAT != HOST_FLOAT_FORMAT
1624 # error IEEE emulation needed
1625 #endif
1626 REAL_VALUE_FROM_CONST_DOUBLE (u.d, x);
1627 u2.f = d;
1628 return u2.i;
1629 }
1630 \f
1631 /* This function generates the assembly code for function entry.
1632 The macro FUNCTION_PROLOGUE in i860.h is defined to call this function.
1633
1634 ASM_FILE is a stdio stream to output the code to.
1635 SIZE is an int: how many units of temporary storage to allocate.
1636
1637 Refer to the array `regs_ever_live' to determine which registers
1638 to save; `regs_ever_live[I]' is nonzero if register number I
1639 is ever used in the function. This macro is responsible for
1640 knowing which registers should not be saved even if used.
1641
1642 NOTE: `frame_lower_bytes' is the count of bytes which will lie
1643 between the new `fp' value and the new `sp' value after the
1644 prologue is done. `frame_upper_bytes' is the count of bytes
1645 that will lie between the new `fp' and the *old* `sp' value
1646 after the new `fp' is setup (in the prologue). The upper
1647 part of each frame always includes at least 2 words (8 bytes)
1648 to hold the saved frame pointer and the saved return address.
1649
1650 The svr4 ABI for the i860 now requires that the values of the
1651 stack pointer and frame pointer registers be kept aligned to
1652 16-byte boundaries at all times. We obey that restriction here.
1653
1654 The svr4 ABI for the i860 is entirely vague when it comes to specifying
1655 exactly where the "preserved" registers should be saved. The native
1656 svr4 C compiler I now have doesn't help to clarify the requirements
1657 very much because it is plainly out-of-date and non-ABI-compliant
1658 (in at least one important way, i.e. how it generates function
1659 epilogues).
1660
1661 The native svr4 C compiler saves the "preserved" registers (i.e.
1662 r4-r15 and f2-f7) in the lower part of a frame (i.e. at negative
1663 offsets from the frame pointer).
1664
1665 Previous versions of GCC also saved the "preserved" registers in the
1666 "nagative" part of the frame, but they saved them using positive
1667 offsets from the (adjusted) stack pointer (after it had been adjusted
1668 to allocate space for the new frame). That's just plain wrong
1669 because if the current function calls alloca(), the stack pointer
1670 will get moved, and it will be impossible to restore the registers
1671 properly again after that.
1672
1673 Both compilers handled parameter registers (i.e. r16-r27 and f8-f15)
1674 by copying their values either into various "preserved" registers or
1675 into stack slots in the lower part of the current frame (as seemed
1676 appropriate, depending upon subsequent usage of these values).
1677
1678 Here we want to save the preserved registers at some offset from the
1679 frame pointer register so as to avoid any possible problems arising
1680 from calls to alloca(). We can either save them at small positive
1681 offsets from the frame pointer, or at small negative offsets from
1682 the frame pointer. If we save them at small negative offsets from
1683 the frame pointer (i.e. in the lower part of the frame) then we
1684 must tell the rest of GCC (via STARTING_FRAME_OFFSET) exactly how
1685 many bytes of space we plan to use in the lower part of the frame
1686 for this purpose. Since other parts of the compiler reference the
1687 value of STARTING_FRAME_OFFSET long before final() calls this function,
1688 we would have to go ahead and assume the worst-case storage requirements
1689 for saving all of the "preserved" registers (and use that number, i.e.
1690 `80', to define STARTING_FRAME_OFFSET) if we wanted to save them in
1691 the lower part of the frame. That could potentially be very wasteful,
1692 and that wastefulness could really hamper people compiling for embedded
1693 i860 targets with very tight limits on stack space. Thus, we choose
1694 here to save the preserved registers in the upper part of the
1695 frame, so that we can decide at the very last minute how much (or how
1696 little) space we must allocate for this purpose.
1697
1698 To satisfy the needs of the svr4 ABI "tdesc" scheme, preserved
1699 registers must always be saved so that the saved values of registers
1700 with higher numbers are at higher addresses. We obey that restriction
1701 here.
1702
1703 There are two somewhat different ways that you can generate prologues
1704 here... i.e. pedantically ABI-compliant, and the "other" way. The
1705 "other" way is more consistant with what is currently generated by the
1706 "native" svr4 C compiler for the i860. That's important if you want
1707 to use the current (as of 8/91) incarnation of svr4 SDB for the i860.
1708 The SVR4 SDB for the i860 insists on having function prologues be
1709 non-ABI-compliant!
1710
1711 To get fully ABI-compliant prologues, define I860_STRICT_ABI_PROLOGUES
1712 in the i860svr4.h file. (By default this is *not* defined).
1713
1714 The differences between the ABI-compliant and non-ABI-compliant prologues
1715 are that (a) the ABI version seems to require the use of *signed*
1716 (rather than unsigned) adds and subtracts, and (b) the ordering of
1717 the various steps (e.g. saving preserved registers, saving the
1718 return address, setting up the new frame pointer value) is different.
1719
1720 For strict ABI compliance, it seems to be the case that the very last
1721 thing that is supposed to happen in the prologue is getting the frame
1722 pointer set to its new value (but only after everything else has
1723 already been properly setup). We do that here, but only if the symbol
1724 I860_STRICT_ABI_PROLOGUES is defined.
1725 */
1726
1727 #ifndef STACK_ALIGNMENT
1728 #define STACK_ALIGNMENT 16
1729 #endif
1730
1731 extern char call_used_regs[];
1732 extern int leaf_function_p ();
1733
1734 char *current_function_original_name;
1735
1736 static int must_preserve_r1;
1737 static unsigned must_preserve_bytes;
1738
1739 void
1740 function_prologue (asm_file, local_bytes)
1741 register FILE *asm_file;
1742 register unsigned local_bytes;
1743 {
1744 register unsigned frame_lower_bytes;
1745 register unsigned frame_upper_bytes;
1746 register unsigned total_fsize;
1747 register unsigned preserved_reg_bytes = 0;
1748 register unsigned i;
1749 register unsigned preserved_so_far = 0;
1750
1751 must_preserve_r1 = (optimize < 2 || ! leaf_function_p ());
1752 must_preserve_bytes = 4 + (must_preserve_r1 ? 4 : 0);
1753
1754 /* Count registers that need preserving. Ignore r0. It never needs
1755 preserving. */
1756
1757 for (i = 1; i < FIRST_PSEUDO_REGISTER; i++)
1758 {
1759 if (regs_ever_live[i] && ! call_used_regs[i])
1760 preserved_reg_bytes += 4;
1761 }
1762
1763 /* Round-up the frame_lower_bytes so that it's a multiple of 16. */
1764
1765 frame_lower_bytes = (local_bytes + STACK_ALIGNMENT - 1) & -STACK_ALIGNMENT;
1766
1767 /* The upper part of each frame will contain the saved fp,
1768 the saved r1, and stack slots for all of the other "preserved"
1769 registers that we find we will need to save & restore. */
1770
1771 frame_upper_bytes = must_preserve_bytes + preserved_reg_bytes;
1772
1773 /* Round-up the frame_upper_bytes so that it's a multiple of 16. */
1774
1775 frame_upper_bytes
1776 = (frame_upper_bytes + STACK_ALIGNMENT - 1) & -STACK_ALIGNMENT;
1777
1778 total_fsize = frame_upper_bytes + frame_lower_bytes;
1779
1780 #ifndef I860_STRICT_ABI_PROLOGUES
1781
1782 /* There are two kinds of function prologues.
1783 You use the "small" version if the total frame size is
1784 small enough so that it can fit into an immediate 16-bit
1785 value in one instruction. Otherwise, you use the "large"
1786 version of the function prologue. */
1787
1788 if (total_fsize > 0x7fff)
1789 {
1790 /* Adjust the stack pointer. The ABI sez to do this using `adds',
1791 but the native C compiler on svr4 uses `addu'. */
1792
1793 fprintf (asm_file, "\taddu -%d,%ssp,%ssp\n",
1794 frame_upper_bytes, i860_reg_prefix, i860_reg_prefix);
1795
1796 /* Save the old frame pointer. */
1797
1798 fprintf (asm_file, "\tst.l %sfp,0(%ssp)\n",
1799 i860_reg_prefix, i860_reg_prefix);
1800
1801 /* Setup the new frame pointer. The ABI sez to do this after
1802 preserving registers (using adds), but that's not what the
1803 native C compiler on svr4 does. */
1804
1805 fprintf (asm_file, "\taddu 0,%ssp,%sfp\n",
1806 i860_reg_prefix, i860_reg_prefix);
1807
1808 /* Get the value of frame_lower_bytes into r31. */
1809
1810 fprintf (asm_file, "\torh %d,%sr0,%sr31\n",
1811 frame_lower_bytes >> 16, i860_reg_prefix, i860_reg_prefix);
1812 fprintf (asm_file, "\tor %d,%sr31,%sr31\n",
1813 frame_lower_bytes & 0xffff, i860_reg_prefix, i860_reg_prefix);
1814
1815 /* Now re-adjust the stack pointer using the value in r31.
1816 The ABI sez to do this with `subs' but SDB may prefer `subu'. */
1817
1818 fprintf (asm_file, "\tsubu %ssp,%sr31,%ssp\n",
1819 i860_reg_prefix, i860_reg_prefix, i860_reg_prefix);
1820
1821 /* Preserve registers. The ABI sez to do this before setting
1822 up the new frame pointer, but that's not what the native
1823 C compiler on svr4 does. */
1824
1825 for (i = 1; i < 32; i++)
1826 if (regs_ever_live[i] && ! call_used_regs[i])
1827 fprintf (asm_file, "\tst.l %s%s,%d(%sfp)\n",
1828 i860_reg_prefix, reg_names[i],
1829 must_preserve_bytes + (4 * preserved_so_far++),
1830 i860_reg_prefix);
1831
1832 for (i = 32; i < 64; i++)
1833 if (regs_ever_live[i] && ! call_used_regs[i])
1834 fprintf (asm_file, "\tfst.l %s%s,%d(%sfp)\n",
1835 i860_reg_prefix, reg_names[i],
1836 must_preserve_bytes + (4 * preserved_so_far++),
1837 i860_reg_prefix);
1838
1839 /* Save the return address. */
1840
1841 if (must_preserve_r1)
1842 fprintf (asm_file, "\tst.l %sr1,4(%sfp)\n",
1843 i860_reg_prefix, i860_reg_prefix);
1844 }
1845 else
1846 {
1847 /* Adjust the stack pointer. The ABI sez to do this using `adds',
1848 but the native C compiler on svr4 uses `addu'. */
1849
1850 fprintf (asm_file, "\taddu -%d,%ssp,%ssp\n",
1851 total_fsize, i860_reg_prefix, i860_reg_prefix);
1852
1853 /* Save the old frame pointer. */
1854
1855 fprintf (asm_file, "\tst.l %sfp,%d(%ssp)\n",
1856 i860_reg_prefix, frame_lower_bytes, i860_reg_prefix);
1857
1858 /* Setup the new frame pointer. The ABI sez to do this after
1859 preserving registers and after saving the return address,
1860 (and its saz to do this using adds), but that's not what the
1861 native C compiler on svr4 does. */
1862
1863 fprintf (asm_file, "\taddu %d,%ssp,%sfp\n",
1864 frame_lower_bytes, i860_reg_prefix, i860_reg_prefix);
1865
1866 /* Preserve registers. The ABI sez to do this before setting
1867 up the new frame pointer, but that's not what the native
1868 compiler on svr4 does. */
1869
1870 for (i = 1; i < 32; i++)
1871 if (regs_ever_live[i] && ! call_used_regs[i])
1872 fprintf (asm_file, "\tst.l %s%s,%d(%sfp)\n",
1873 i860_reg_prefix, reg_names[i],
1874 must_preserve_bytes + (4 * preserved_so_far++),
1875 i860_reg_prefix);
1876
1877 for (i = 32; i < 64; i++)
1878 if (regs_ever_live[i] && ! call_used_regs[i])
1879 fprintf (asm_file, "\tfst.l %s%s,%d(%sfp)\n",
1880 i860_reg_prefix, reg_names[i],
1881 must_preserve_bytes + (4 * preserved_so_far++),
1882 i860_reg_prefix);
1883
1884 /* Save the return address. The ABI sez to do this earlier,
1885 and also via an offset from %sp, but the native C compiler
1886 on svr4 does it later (i.e. now) and uses an offset from
1887 %fp. */
1888
1889 if (must_preserve_r1)
1890 fprintf (asm_file, "\tst.l %sr1,4(%sfp)\n",
1891 i860_reg_prefix, i860_reg_prefix);
1892 }
1893
1894 #else /* defined(I860_STRICT_ABI_PROLOGUES) */
1895
1896 /* There are two kinds of function prologues.
1897 You use the "small" version if the total frame size is
1898 small enough so that it can fit into an immediate 16-bit
1899 value in one instruction. Otherwise, you use the "large"
1900 version of the function prologue. */
1901
1902 if (total_fsize > 0x7fff)
1903 {
1904 /* Adjust the stack pointer (thereby allocating a new frame). */
1905
1906 fprintf (asm_file, "\tadds -%d,%ssp,%ssp\n",
1907 frame_upper_bytes, i860_reg_prefix, i860_reg_prefix);
1908
1909 /* Save the caller's frame pointer. */
1910
1911 fprintf (asm_file, "\tst.l %sfp,0(%ssp)\n",
1912 i860_reg_prefix, i860_reg_prefix);
1913
1914 /* Save return address. */
1915
1916 if (must_preserve_r1)
1917 fprintf (asm_file, "\tst.l %sr1,4(%ssp)\n",
1918 i860_reg_prefix, i860_reg_prefix);
1919
1920 /* Get the value of frame_lower_bytes into r31 for later use. */
1921
1922 fprintf (asm_file, "\torh %d,%sr0,%sr31\n",
1923 frame_lower_bytes >> 16, i860_reg_prefix, i860_reg_prefix);
1924 fprintf (asm_file, "\tor %d,%sr31,%sr31\n",
1925 frame_lower_bytes & 0xffff, i860_reg_prefix, i860_reg_prefix);
1926
1927 /* Now re-adjust the stack pointer using the value in r31. */
1928
1929 fprintf (asm_file, "\tsubs %ssp,%sr31,%ssp\n",
1930 i860_reg_prefix, i860_reg_prefix, i860_reg_prefix);
1931
1932 /* Pre-compute value to be used as the new frame pointer. */
1933
1934 fprintf (asm_file, "\tadds %ssp,%sr31,%sr31\n",
1935 i860_reg_prefix, i860_reg_prefix, i860_reg_prefix);
1936
1937 /* Preserve registers. */
1938
1939 for (i = 1; i < 32; i++)
1940 if (regs_ever_live[i] && ! call_used_regs[i])
1941 fprintf (asm_file, "\tst.l %s%s,%d(%sr31)\n",
1942 i860_reg_prefix, reg_names[i],
1943 must_preserve_bytes + (4 * preserved_so_far++),
1944 i860_reg_prefix);
1945
1946 for (i = 32; i < 64; i++)
1947 if (regs_ever_live[i] && ! call_used_regs[i])
1948 fprintf (asm_file, "\tfst.l %s%s,%d(%sr31)\n",
1949 i860_reg_prefix, reg_names[i],
1950 must_preserve_bytes + (4 * preserved_so_far++),
1951 i860_reg_prefix);
1952
1953 /* Actually set the new value of the frame pointer. */
1954
1955 fprintf (asm_file, "\tmov %sr31,%sfp\n",
1956 i860_reg_prefix, i860_reg_prefix);
1957 }
1958 else
1959 {
1960 /* Adjust the stack pointer. */
1961
1962 fprintf (asm_file, "\tadds -%d,%ssp,%ssp\n",
1963 total_fsize, i860_reg_prefix, i860_reg_prefix);
1964
1965 /* Save the caller's frame pointer. */
1966
1967 fprintf (asm_file, "\tst.l %sfp,%d(%ssp)\n",
1968 i860_reg_prefix, frame_lower_bytes, i860_reg_prefix);
1969
1970 /* Save the return address. */
1971
1972 if (must_preserve_r1)
1973 fprintf (asm_file, "\tst.l %sr1,%d(%ssp)\n",
1974 i860_reg_prefix, frame_lower_bytes + 4, i860_reg_prefix);
1975
1976 /* Preserve registers. */
1977
1978 for (i = 1; i < 32; i++)
1979 if (regs_ever_live[i] && ! call_used_regs[i])
1980 fprintf (asm_file, "\tst.l %s%s,%d(%ssp)\n",
1981 i860_reg_prefix, reg_names[i],
1982 frame_lower_bytes + must_preserve_bytes + (4 * preserved_so_far++),
1983 i860_reg_prefix);
1984
1985 for (i = 32; i < 64; i++)
1986 if (regs_ever_live[i] && ! call_used_regs[i])
1987 fprintf (asm_file, "\tfst.l %s%s,%d(%ssp)\n",
1988 i860_reg_prefix, reg_names[i],
1989 frame_lower_bytes + must_preserve_bytes + (4 * preserved_so_far++),
1990 i860_reg_prefix);
1991
1992 /* Setup the new frame pointer. */
1993
1994 fprintf (asm_file, "\tadds %d,%ssp,%sfp\n",
1995 frame_lower_bytes, i860_reg_prefix, i860_reg_prefix);
1996 }
1997 #endif /* defined(I860_STRICT_ABI_PROLOGUES) */
1998
1999 #ifdef ASM_OUTPUT_PROLOGUE_SUFFIX
2000 ASM_OUTPUT_PROLOGUE_SUFFIX (asm_file);
2001 #endif /* defined(ASM_OUTPUT_PROLOGUE_SUFFIX) */
2002 }
2003 \f
2004 /* This function generates the assembly code for function exit.
2005 The macro FUNCTION_EPILOGUE in i860.h is defined to call this function.
2006
2007 ASM_FILE is a stdio stream to output the code to.
2008 SIZE is an int: how many units of temporary storage to allocate.
2009
2010 The function epilogue should not depend on the current stack pointer!
2011 It should use the frame pointer only. This is mandatory because
2012 of alloca; we also take advantage of it to omit stack adjustments
2013 before returning.
2014
2015 Note that when we go to restore the preserved register values we must
2016 not try to address their slots by using offsets from the stack pointer.
2017 That's because the stack pointer may have been moved during the function
2018 execution due to a call to alloca(). Rather, we must restore all
2019 preserved registers via offsets from the frame pointer value.
2020
2021 Note also that when the current frame is being "popped" (by adjusting
2022 the value of the stack pointer) on function exit, we must (for the
2023 sake of alloca) set the new value of the stack pointer based upon
2024 the current value of the frame pointer. We can't just add what we
2025 believe to be the (static) frame size to the stack pointer because
2026 if we did that, and alloca() had been called during this function,
2027 we would end up returning *without* having fully deallocated all of
2028 the space grabbed by alloca. If that happened, and a function
2029 containing one or more alloca() calls was called over and over again,
2030 then the stack would grow without limit!
2031
2032 Finally note that the epilogues generated here are completely ABI
2033 compliant. They go out of their way to insure that the value in
2034 the frame pointer register is never less than the value in the stack
2035 pointer register. It's not clear why this relationship needs to be
2036 maintained at all times, but maintaining it only costs one extra
2037 instruction, so what the hell.
2038 */
2039
2040 void
2041 function_epilogue (asm_file, local_bytes)
2042 register FILE *asm_file;
2043 register unsigned local_bytes;
2044 {
2045 register unsigned frame_upper_bytes;
2046 register unsigned preserved_reg_bytes = 0;
2047 register unsigned i;
2048 register unsigned restored_so_far = 0;
2049
2050 /* Count the number of registers that were preserved in the prologue.
2051 Ignore r0. It is never preserved. */
2052
2053 for (i = 1; i < FIRST_PSEUDO_REGISTER; i++)
2054 {
2055 if (regs_ever_live[i] && ! call_used_regs[i])
2056 preserved_reg_bytes += 4;
2057 }
2058
2059 /* The upper part of each frame will contain only saved fp,
2060 the saved r1, and stack slots for all of the other "preserved"
2061 registers that we find we will need to save & restore. */
2062
2063 frame_upper_bytes = must_preserve_bytes + preserved_reg_bytes;
2064
2065 /* Round-up frame_upper_bytes so that t is a multiple of 16. */
2066
2067 frame_upper_bytes
2068 = (frame_upper_bytes + STACK_ALIGNMENT - 1) & -STACK_ALIGNMENT;
2069
2070 /* Restore all of the "preserved" registers that need restoring. */
2071
2072 for (i = 1; i < 32; i++)
2073 if (regs_ever_live[i] && ! call_used_regs[i])
2074 fprintf (asm_file, "\tld.l %d(%sfp),%s%s\n",
2075 must_preserve_bytes + (4 * restored_so_far++),
2076 i860_reg_prefix, i860_reg_prefix, reg_names[i]);
2077
2078 for (i = 32; i < 64; i++)
2079 if (regs_ever_live[i] && ! call_used_regs[i])
2080 fprintf (asm_file, "\tfld.l %d(%sfp),%s%s\n",
2081 must_preserve_bytes + (4 * restored_so_far++),
2082 i860_reg_prefix, i860_reg_prefix, reg_names[i]);
2083
2084 /* Get the value we plan to use to restore the stack pointer into r31. */
2085
2086 fprintf (asm_file, "\tadds %d,%sfp,%sr31\n",
2087 frame_upper_bytes, i860_reg_prefix, i860_reg_prefix);
2088
2089 /* Restore the return address and the old frame pointer. */
2090
2091 if (must_preserve_r1)
2092 fprintf (asm_file, "\tld.l 4(%sfp),%sr1\n",
2093 i860_reg_prefix, i860_reg_prefix);
2094
2095 fprintf (asm_file, "\tld.l 0(%sfp),%sfp\n",
2096 i860_reg_prefix, i860_reg_prefix);
2097
2098 /* Return and restore the old stack pointer value. */
2099
2100 fprintf (asm_file, "\tbri %sr1\n\tmov %sr31,%ssp\n",
2101 i860_reg_prefix, i860_reg_prefix, i860_reg_prefix);
2102 }