3 * File name: ir/ir/iropt.c
4 * Purpose: iropt --- optimizations intertwined with IR construction.
5 * Author: Christian Schaefer
6 * Modified by: Goetz Lindenmaier
9 * Copyright: (c) 1998-2003 Universität Karlsruhe
10 * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
17 # include "irnode_t.h"
18 # include "irgraph_t.h"
19 # include "irmode_t.h"
21 # include "ircons_t.h"
25 # include "dbginfo_t.h"
26 # include "iropt_dbg.h"
27 # include "irflag_t.h"
28 # include "firmstat.h"
30 /* Make types visible to allow most efficient access */
31 # include "entity_t.h"
34 * Trivial INLINEable routine for copy propagation.
35 * Does follow Ids, needed to optimize INLINEd code.
37 static INLINE ir_node *
38 follow_Id (ir_node *n)
40 while (get_irn_op (n) == op_Id) n = get_Id_pred (n);
45 * Returns the tarval of a Const node or tarval_bad for all other nodes.
47 static INLINE tarval *
50 if ((n != NULL) && (get_irn_op(n) == op_Const))
51 return get_Const_tarval(n); /* might return tarval_bad */
57 * return the value of a Constant
59 static tarval *computed_value_Const(ir_node *n)
61 return get_Const_tarval(n);
65 * return the value of a 'sizeof' SymConst
67 static tarval *computed_value_SymConst(ir_node *n)
69 if ((get_SymConst_kind(n) == symconst_size) &&
70 (get_type_state(get_SymConst_type(n))) == layout_fixed)
71 return new_tarval_from_long(get_type_size_bytes(get_SymConst_type(n)), get_irn_mode(n));
75 static tarval *computed_value_Add(ir_node *n)
77 ir_node *a = get_Add_left(n);
78 ir_node *b = get_Add_right(n);
80 tarval *ta = value_of(a);
81 tarval *tb = value_of(b);
83 if ((ta != tarval_bad) && (tb != tarval_bad)
84 && (get_irn_mode(a) == get_irn_mode(b))
85 && !(get_mode_sort(get_irn_mode(a)) == irms_reference)) {
86 return tarval_add(ta, tb);
91 static tarval *computed_value_Sub(ir_node *n)
93 ir_node *a = get_Sub_left(n);
94 ir_node *b = get_Sub_right(n);
96 tarval *ta = value_of(a);
97 tarval *tb = value_of(b);
99 if ((ta != tarval_bad) && (tb != tarval_bad)
100 && (get_irn_mode(a) == get_irn_mode(b))
101 && !(get_mode_sort(get_irn_mode(a)) == irms_reference)) {
102 return tarval_sub(ta, tb);
107 static tarval *computed_value_Minus(ir_node *n)
109 ir_node *a = get_Minus_op(n);
110 tarval *ta = value_of(a);
112 if ((ta != tarval_bad) && mode_is_signed(get_irn_mode(a)))
113 return tarval_neg(ta);
118 static tarval *computed_value_Mul(ir_node *n)
120 ir_node *a = get_Mul_left(n);
121 ir_node *b = get_Mul_right(n);
123 tarval *ta = value_of(a);
124 tarval *tb = value_of(b);
126 if ((ta != tarval_bad) && (tb != tarval_bad) && (get_irn_mode(a) == get_irn_mode(b))) {
127 return tarval_mul(ta, tb);
129 /* a*0 = 0 or 0*b = 0:
130 calls computed_value recursive and returns the 0 with proper
134 if ( ( ((v = ta) != tarval_bad)
135 && (v == get_mode_null(get_tarval_mode(v))) )
136 || ( ((v = tb) != tarval_bad)
137 && (v == get_mode_null(get_tarval_mode(v))) )) {
144 static tarval *computed_value_Quot(ir_node *n)
146 ir_node *a = get_Quot_left(n);
147 ir_node *b = get_Quot_right(n);
149 tarval *ta = value_of(a);
150 tarval *tb = value_of(b);
152 /* This was missing in original implementation. Why? */
153 if ((ta != tarval_bad) && (tb != tarval_bad) && (get_irn_mode(a) == get_irn_mode(b))) {
154 if (tb != get_mode_null(get_tarval_mode(tb))) /* div by zero: return tarval_bad */
155 return tarval_quo(ta, tb);
160 static tarval *computed_value_Div(ir_node *n)
162 ir_node *a = get_Div_left(n);
163 ir_node *b = get_Div_right(n);
165 tarval *ta = value_of(a);
166 tarval *tb = value_of(b);
168 /* This was missing in original implementation. Why? */
169 if ((ta != tarval_bad) && (tb != tarval_bad) && (get_irn_mode(a) == get_irn_mode(b))) {
170 if (tb != get_mode_null(get_tarval_mode(tb))) /* div by zero: return tarval_bad */
171 return tarval_div(ta, tb);
176 static tarval *computed_value_Mod(ir_node *n)
178 ir_node *a = get_Mod_left(n);
179 ir_node *b = get_Mod_right(n);
181 tarval *ta = value_of(a);
182 tarval *tb = value_of(b);
184 /* This was missing in original implementation. Why? */
185 if ((ta != tarval_bad) && (tb != tarval_bad) && (get_irn_mode(a) == get_irn_mode(b))) {
186 if (tb != get_mode_null(get_tarval_mode(tb))) /* div by zero: return tarval_bad */
187 return tarval_mod(ta, tb);
192 static tarval *computed_value_Abs(ir_node *n)
194 ir_node *a = get_Abs_op(n);
195 tarval *ta = value_of(a);
197 if (ta != tarval_bad)
198 return tarval_abs(ta);
203 static tarval *computed_value_And(ir_node *n)
205 ir_node *a = get_And_left(n);
206 ir_node *b = get_And_right(n);
208 tarval *ta = value_of(a);
209 tarval *tb = value_of(b);
211 if ((ta != tarval_bad) && (tb != tarval_bad)) {
212 return tarval_and (ta, tb);
216 if ( (classify_tarval ((v = computed_value (a))) == TV_CLASSIFY_NULL)
217 || (classify_tarval ((v = computed_value (b))) == TV_CLASSIFY_NULL)) {
224 static tarval *computed_value_Or(ir_node *n)
226 ir_node *a = get_Or_left(n);
227 ir_node *b = get_Or_right(n);
229 tarval *ta = value_of(a);
230 tarval *tb = value_of(b);
232 if ((ta != tarval_bad) && (tb != tarval_bad)) {
233 return tarval_or (ta, tb);
236 if ( (classify_tarval ((v = computed_value (a))) == TV_CLASSIFY_ALL_ONE)
237 || (classify_tarval ((v = computed_value (b))) == TV_CLASSIFY_ALL_ONE)) {
244 static tarval *computed_value_Eor(ir_node *n)
246 ir_node *a = get_Eor_left(n);
247 ir_node *b = get_Eor_right(n);
249 tarval *ta = value_of(a);
250 tarval *tb = value_of(b);
252 if ((ta != tarval_bad) && (tb != tarval_bad)) {
253 return tarval_eor (ta, tb);
258 static tarval *computed_value_Not(ir_node *n)
260 ir_node *a = get_Not_op(n);
261 tarval *ta = value_of(a);
263 if (ta != tarval_bad)
264 return tarval_not(ta);
269 static tarval *computed_value_Shl(ir_node *n)
271 ir_node *a = get_Shl_left(n);
272 ir_node *b = get_Shl_right(n);
274 tarval *ta = value_of(a);
275 tarval *tb = value_of(b);
277 if ((ta != tarval_bad) && (tb != tarval_bad)) {
278 return tarval_shl (ta, tb);
283 static tarval *computed_value_Shr(ir_node *n)
285 ir_node *a = get_Shr_left(n);
286 ir_node *b = get_Shr_right(n);
288 tarval *ta = value_of(a);
289 tarval *tb = value_of(b);
291 if ((ta != tarval_bad) && (tb != tarval_bad)) {
292 return tarval_shr (ta, tb);
297 static tarval *computed_value_Shrs(ir_node *n)
299 ir_node *a = get_Shrs_left(n);
300 ir_node *b = get_Shrs_right(n);
302 tarval *ta = value_of(a);
303 tarval *tb = value_of(b);
305 if ((ta != tarval_bad) && (tb != tarval_bad)) {
306 return tarval_shrs (ta, tb);
311 static tarval *computed_value_Rot(ir_node *n)
313 ir_node *a = get_Rot_left(n);
314 ir_node *b = get_Rot_right(n);
316 tarval *ta = value_of(a);
317 tarval *tb = value_of(b);
319 if ((ta != tarval_bad) && (tb != tarval_bad)) {
320 return tarval_rot (ta, tb);
325 static tarval *computed_value_Conv(ir_node *n)
327 ir_node *a = get_Conv_op(n);
328 tarval *ta = value_of(a);
330 if (ta != tarval_bad)
331 return tarval_convert_to(ta, get_irn_mode(n));
336 static tarval *computed_value_Proj(ir_node *n)
338 ir_node *a = get_Proj_pred(n), *b;
341 /* Optimize Cmp nodes.
342 This performs a first step of unreachable code elimination.
343 Proj can not be computed, but folding a Cmp above the Proj here is
344 not as wasteful as folding a Cmp into a Tuple of 16 Consts of which
346 There are several case where we can evaluate a Cmp node:
347 1. The nodes compared are both the same. If we compare for
348 equal, greater equal, ... this will return true, else it
349 will return false. This step relies on cse.
350 2. The predecessors of Cmp are target values. We can evaluate
352 3. The predecessors are Allocs or void* constants. Allocs never
353 return NULL, they raise an exception. Therefore we can predict
355 switch (get_irn_opcode(a)) {
357 aa = get_Cmp_left(a);
358 ab = get_Cmp_right(a);
360 if (aa == ab) { /* 1.: */
361 /* This is a trick with the bits used for encoding the Cmp
362 Proj numbers, the following statement is not the same:
363 return new_tarval_from_long ((get_Proj_proj(n) == Eq), mode_b) */
364 return new_tarval_from_long ((get_Proj_proj(n) & Eq), mode_b);
366 tarval *taa = computed_value (aa);
367 tarval *tab = computed_value (ab);
369 if ((taa != tarval_bad) && (tab != tarval_bad)) { /* 2.: */
370 /* strange checks... */
371 pnc_number flags = tarval_cmp (taa, tab);
372 if (flags != False) {
373 return new_tarval_from_long (get_Proj_proj(n) & flags, mode_b);
375 } else { /* check for 3.: */
376 ir_node *aaa = skip_Id(skip_Proj(aa));
377 ir_node *aba = skip_Id(skip_Proj(ab));
379 if ( ( (/* aa is ProjP and aaa is Alloc */
380 (get_irn_op(aa) == op_Proj)
381 && (mode_is_reference(get_irn_mode(aa)))
382 && (get_irn_op(aaa) == op_Alloc))
383 && ( (/* ab is constant void */
384 (get_irn_op(ab) == op_Const)
385 && (mode_is_reference(get_irn_mode(ab)))
386 && (get_Const_tarval(ab) == get_mode_null(get_irn_mode(ab))))
387 || (/* ab is other Alloc */
388 (get_irn_op(ab) == op_Proj)
389 && (mode_is_reference(get_irn_mode(ab)))
390 && (get_irn_op(aba) == op_Alloc)
392 || (/* aa is void and aba is Alloc */
393 (get_irn_op(aa) == op_Const)
394 && (mode_is_reference(get_irn_mode(aa)))
395 && (get_Const_tarval(aa) == get_mode_null(get_irn_mode(aa)))
396 && (get_irn_op(ab) == op_Proj)
397 && (mode_is_reference(get_irn_mode(ab)))
398 && (get_irn_op(aba) == op_Alloc)))
400 return new_tarval_from_long (get_Proj_proj(n) & Ne, mode_b);
407 tarval *tb = value_of(b = get_DivMod_right(a));
408 tarval *ta = value_of(a = get_DivMod_left(a));
410 if ((ta != tarval_bad) && (tb != tarval_bad) && (get_irn_mode(a) == get_irn_mode(b))) {
411 if (tb == get_mode_null(get_tarval_mode(tb))) /* div by zero: return tarval_bad */
413 if (get_Proj_proj(n)== pn_DivMod_res_div)
414 return tarval_div(ta, tb);
415 else if (get_Proj_proj(n)== pn_DivMod_res_mod)
416 return tarval_mod(ta, tb);
423 tarval *tb = value_of(b = get_Div_right(a));
424 tarval *ta = value_of(a = get_Div_left(a));
426 if ((ta != tarval_bad) && (tb != tarval_bad) && (get_irn_mode(a) == get_irn_mode(b))) {
427 if (tb == get_mode_null(get_tarval_mode(tb))) /* div by zero: return tarval_bad */
429 if (get_Proj_proj(n)== pn_Div_res)
430 return tarval_div(ta, tb);
437 tarval *tb = value_of(b = get_Mod_right(a));
438 tarval *ta = value_of(a = get_Mod_left(a));
440 if ((ta != tarval_bad) && (tb != tarval_bad) && (get_irn_mode(a) == get_irn_mode(b))) {
441 if (tb == get_mode_null(get_tarval_mode(tb))) /* div by zero: return tarval_bad */
443 if (get_Proj_proj(n)== pn_Mod_res)
444 return tarval_mod(ta, tb);
456 * If the parameter n can be computed, return its value, else tarval_bad.
457 * Performs constant folding.
459 * @param n The node this should be evaluated
461 tarval *computed_value(ir_node *n)
463 if (n->op->computed_value)
464 return n->op->computed_value(n);
469 * set the default computed_value evaluator
471 static ir_op *firm_set_default_computed_value(ir_op *op)
475 op->computed_value = computed_value_##a; \
500 op->computed_value = NULL;
508 /* returns 1 if the a and b are pointers to different locations. */
510 different_identity (ir_node *a, ir_node *b)
512 assert (mode_is_reference(get_irn_mode (a))
513 && mode_is_reference(get_irn_mode (b)));
515 if (get_irn_op (a) == op_Proj && get_irn_op(b) == op_Proj) {
516 ir_node *a1 = get_Proj_pred (a);
517 ir_node *b1 = get_Proj_pred (b);
518 if (a1 != b1 && get_irn_op (a1) == op_Alloc
519 && get_irn_op (b1) == op_Alloc)
526 static ir_node *equivalent_node_Block(ir_node *n)
530 /* The Block constructor does not call optimize, but mature_immBlock
531 calls the optimization. */
532 assert(get_Block_matured(n));
534 /* Straightening: a single entry Block following a single exit Block
535 can be merged, if it is not the Start block. */
536 /* !!! Beware, all Phi-nodes of n must have been optimized away.
537 This should be true, as the block is matured before optimize is called.
538 But what about Phi-cycles with the Phi0/Id that could not be resolved?
539 Remaining Phi nodes are just Ids. */
540 if ((get_Block_n_cfgpreds(n) == 1) &&
541 (get_irn_op(get_Block_cfgpred(n, 0)) == op_Jmp)) {
542 ir_node *predblock = get_nodes_block(get_Block_cfgpred(n, 0));
543 if (predblock == oldn) {
544 /* Jmp jumps into the block it is in -- deal self cycle. */
545 n = new_Bad(); DBG_OPT_DEAD;
546 } else if (get_opt_control_flow_straightening()) {
547 n = predblock; DBG_OPT_STG;
550 else if ((get_Block_n_cfgpreds(n) == 1) &&
551 (get_irn_op(skip_Proj(get_Block_cfgpred(n, 0))) == op_Cond)) {
552 ir_node *predblock = get_nodes_block(get_Block_cfgpred(n, 0));
553 if (predblock == oldn) {
554 /* Jmp jumps into the block it is in -- deal self cycle. */
555 n = new_Bad(); DBG_OPT_DEAD;
558 else if ((get_Block_n_cfgpreds(n) == 2) &&
559 (get_opt_control_flow_weak_simplification())) {
560 /* Test whether Cond jumps twice to this block
561 @@@ we could do this also with two loops finding two preds from several ones. */
562 ir_node *a = get_Block_cfgpred(n, 0);
563 ir_node *b = get_Block_cfgpred(n, 1);
565 if ((get_irn_op(a) == op_Proj) &&
566 (get_irn_op(b) == op_Proj) &&
567 (get_Proj_pred(a) == get_Proj_pred(b)) &&
568 (get_irn_op(get_Proj_pred(a)) == op_Cond) &&
569 (get_irn_mode(get_Cond_selector(get_Proj_pred(a))) == mode_b)) {
570 /* Also a single entry Block following a single exit Block. Phis have
571 twice the same operand and will be optimized away. */
572 n = get_nodes_block(a); DBG_OPT_IFSIM;
574 } else if (get_opt_unreachable_code() &&
575 (n != current_ir_graph->start_block) &&
576 (n != current_ir_graph->end_block) ) {
578 /* If all inputs are dead, this block is dead too, except if it is
579 the start or end block. This is a step of unreachable code
581 for (i = 0; i < get_Block_n_cfgpreds(n); i++) {
582 if (!is_Bad(get_Block_cfgpred(n, i))) break;
584 if (i == get_Block_n_cfgpreds(n))
592 * Returns a equivalent node for a Jmp, a Bad :-)
593 * Of course this only happens if the Block of the Jmp is Bad.
595 static ir_node *equivalent_node_Jmp(ir_node *n)
597 /* GL: Why not same for op_Raise?? */
598 /* unreachable code elimination */
599 if (is_Bad(get_nodes_block(n)))
605 static ir_node *equivalent_node_Cond(ir_node *n)
607 /* We do not evaluate Cond here as we replace it by a new node, a Jmp.
608 See cases for iro_Cond and iro_Proj in transform_node. */
613 * Use algebraic simplification a v a = a.
615 static ir_node *equivalent_node_Or(ir_node *n)
619 ir_node *a = get_Or_left(n);
620 ir_node *b = get_Or_right(n);
624 n = a; DBG_OPT_ALGSIM1;
631 * optimize operations that are commutative and have neutral 0,
632 * so a op 0 = 0 op a = a.
634 static ir_node *equivalent_node_neutral_zero(ir_node *n)
638 ir_node *a = get_binop_left(n);
639 ir_node *b = get_binop_right(n);
644 /* After running compute_node there is only one constant predecessor.
645 Find this predecessors value and remember the other node: */
646 if ((tv = computed_value(a)) != tarval_bad) {
648 } else if ((tv = computed_value(b)) != tarval_bad) {
653 /* If this predecessors constant value is zero, the operation is
654 unnecessary. Remove it: */
655 if (classify_tarval (tv) == TV_CLASSIFY_NULL) {
656 n = on; DBG_OPT_ALGSIM1;
662 #define equivalent_node_Add equivalent_node_neutral_zero
663 #define equivalent_node_Eor equivalent_node_neutral_zero
666 * optimize operations that are not commutative but have neutral 0 on left,
669 static ir_node *equivalent_node_left_zero(ir_node *n)
673 ir_node *a = get_binop_left(n);
674 ir_node *b = get_binop_right(n);
676 if (classify_tarval(computed_value(b)) == TV_CLASSIFY_NULL) {
677 n = a; DBG_OPT_ALGSIM1;
683 #define equivalent_node_Sub equivalent_node_left_zero
684 #define equivalent_node_Shl equivalent_node_left_zero
685 #define equivalent_node_Shr equivalent_node_left_zero
686 #define equivalent_node_Shrs equivalent_node_left_zero
687 #define equivalent_node_Rot equivalent_node_left_zero
690 * Er, a "symmetic unop", ie op(op(n)) = n.
692 static ir_node *equivalent_node_symmetric_unop(ir_node *n)
696 /* optimize symmetric unop */
697 if (get_irn_op(get_unop_op(n)) == get_irn_op(n)) {
698 n = get_unop_op(get_unop_op(n)); DBG_OPT_ALGSIM2;
704 #define equivalent_node_Not equivalent_node_symmetric_unop
706 /* --x == x */ /* ??? Is this possible or can --x raise an
707 out of bounds exception if min =! max? */
708 #define equivalent_node_Minus equivalent_node_symmetric_unop
711 * Optimize a * 1 = 1 * a = a.
713 static ir_node *equivalent_node_Mul(ir_node *n)
717 ir_node *a = get_Mul_left(n);
718 ir_node *b = get_Mul_right(n);
720 /* Mul is commutative and has again an other neutral element. */
721 if (classify_tarval (computed_value (a)) == TV_CLASSIFY_ONE) {
722 n = b; DBG_OPT_ALGSIM1;
723 } else if (classify_tarval (computed_value (b)) == TV_CLASSIFY_ONE) {
724 n = a; DBG_OPT_ALGSIM1;
730 * Optimize a / 1 = a.
732 static ir_node *equivalent_node_Div(ir_node *n)
734 ir_node *a = get_Div_left(n);
735 ir_node *b = get_Div_right(n);
737 /* Div is not commutative. */
738 if (classify_tarval(computed_value(b)) == TV_CLASSIFY_ONE) { /* div(x, 1) == x */
739 /* Turn Div into a tuple (mem, bad, a) */
740 ir_node *mem = get_Div_mem(n);
741 turn_into_tuple(n, 3);
742 set_Tuple_pred(n, pn_Div_M, mem);
743 set_Tuple_pred(n, pn_Div_X_except, new_Bad()); /* no exception */
744 set_Tuple_pred(n, pn_Div_res, a);
750 * Optimize a & 0b1...1 = 0b1...1 & a = a & a = a.
752 static ir_node *equivalent_node_And(ir_node *n)
756 ir_node *a = get_And_left(n);
757 ir_node *b = get_And_right(n);
760 n = a; /* And has it's own neutral element */
761 } else if (classify_tarval(computed_value(a)) == TV_CLASSIFY_ALL_ONE) {
763 } else if (classify_tarval(computed_value(b)) == TV_CLASSIFY_ALL_ONE) {
766 if (n != oldn) DBG_OPT_ALGSIM1;
771 * Try to remove useless conv's:
773 static ir_node *equivalent_node_Conv(ir_node *n)
776 ir_node *a = get_Conv_op(n);
779 ir_mode *n_mode = get_irn_mode(n);
780 ir_mode *a_mode = get_irn_mode(a);
782 if (n_mode == a_mode) { /* No Conv necessary */
783 n = a; DBG_OPT_ALGSIM3;
784 } else if (get_irn_op(a) == op_Conv) { /* Conv(Conv(b)) */
788 n_mode = get_irn_mode(n);
789 b_mode = get_irn_mode(b);
791 if (n_mode == b_mode) {
792 if (n_mode == mode_b) {
793 n = b; /* Convb(Conv*(xxxb(...))) == xxxb(...) */ DBG_OPT_ALGSIM1;
795 else if (mode_is_int(n_mode) || mode_is_character(n_mode)) {
796 if (smaller_mode(b_mode, a_mode)){
797 n = b; /* ConvS(ConvL(xxxS(...))) == xxxS(...) */ DBG_OPT_ALGSIM1;
805 static ir_node *equivalent_node_Phi(ir_node *n)
807 /* Several optimizations:
808 - no Phi in start block.
809 - remove Id operators that are inputs to Phi
810 - fold Phi-nodes, iff they have only one predecessor except
816 ir_node *block = NULL; /* to shutup gcc */
817 ir_node *first_val = NULL; /* to shutup gcc */
818 ir_node *scnd_val = NULL; /* to shutup gcc */
820 if (!get_opt_normalize()) return n;
822 n_preds = get_Phi_n_preds(n);
824 block = get_nodes_block(n);
825 /* @@@ fliegt 'raus, sollte aber doch immer wahr sein!!!
826 assert(get_irn_arity(block) == n_preds && "phi in wrong block!"); */
827 if ((is_Bad(block)) || /* Control dead */
828 (block == current_ir_graph->start_block)) /* There should be no Phi nodes */
829 return new_Bad(); /* in the Start Block. */
831 if (n_preds == 0) return n; /* Phi of dead Region without predecessors. */
834 /* first we test for a special case: */
835 /* Confirm is a special node fixing additional information for a
836 value that is known at a certain point. This is useful for
837 dataflow analysis. */
839 ir_node *a = get_Phi_pred(n, 0);
840 ir_node *b = get_Phi_pred(n, 1);
841 if ( (get_irn_op(a) == op_Confirm)
842 && (get_irn_op(b) == op_Confirm)
843 && follow_Id (get_irn_n(a, 0) == get_irn_n(b, 0))
844 && (get_irn_n(a, 1) == get_irn_n (b, 1))
845 && (a->data.num == (~b->data.num & irpn_True) )) {
846 return get_irn_n(a, 0);
851 /* If the Block has a Bad pred, we also have one. */
852 for (i = 0; i < n_preds; ++i)
853 if (is_Bad (get_Block_cfgpred(block, i)))
854 set_Phi_pred(n, i, new_Bad());
856 /* Find first non-self-referencing input */
857 for (i = 0; i < n_preds; ++i) {
858 first_val = get_Phi_pred(n, i);
859 if ( (first_val != n) /* not self pointer */
861 && (get_irn_op(first_val) != op_Bad)
863 ) { /* value not dead */
864 break; /* then found first value. */
868 /* A totally Bad or self-referencing Phi (we didn't break the above loop) */
869 if (i >= n_preds) { return new_Bad(); }
873 /* follow_Id () for rest of inputs, determine if any of these
874 are non-self-referencing */
875 while (++i < n_preds) {
876 scnd_val = get_Phi_pred(n, i);
878 && (scnd_val != first_val)
880 && (get_irn_op(scnd_val) != op_Bad)
887 /* Fold, if no multiple distinct non-self-referencing inputs */
889 n = first_val; DBG_OPT_PHI;
891 /* skip the remaining Ids (done in get_Phi_pred). */
892 /* superfluous, since we walk all to propagate Block's Bads.
893 while (++i < n_preds) get_Phi_pred(n, i); */
899 * Optimize Loads after Store.
901 * @todo FAILS for volatile entities
903 static ir_node *equivalent_node_Load(ir_node *n)
907 if (!get_opt_redundant_LoadStore()) return n;
909 /* remove unnecessary Load. */
910 ir_node *a = skip_Proj(get_Load_mem(n));
911 ir_node *b = get_Load_ptr(n);
914 /* TODO: check for volatile */
915 if (get_irn_op(a) == op_Store && get_Store_ptr(a) == b) {
916 /* We load immediately after a store -- a read after write. */
917 ir_node *mem = get_Load_mem(n);
919 c = get_Store_value(a);
920 turn_into_tuple(n, 3);
921 set_Tuple_pred(n, pn_Load_M, mem);
922 set_Tuple_pred(n, pn_Load_res, c);
923 set_Tuple_pred(n, pn_Load_X_except, new_Bad()); DBG_OPT_RAW;
929 * Optimize store after store and load after store.
931 * @todo FAILS for volatile entities
933 static ir_node *equivalent_node_Store(ir_node *n)
937 if (!get_opt_redundant_LoadStore()) return n;
939 /* remove unnecessary store. */
940 ir_node *a = skip_Proj(get_Store_mem(n));
941 ir_node *b = get_Store_ptr(n);
942 ir_node *c = skip_Proj(get_Store_value(n));
944 if (get_irn_op(a) == op_Store
945 && get_Store_ptr(a) == b
946 && skip_Proj(get_Store_value(a)) == c) {
947 /* We have twice exactly the same store -- a write after write. */
949 } else if (get_irn_op(c) == op_Load
950 && (a == c || skip_Proj(get_Load_mem(c)) == a)
951 && get_Load_ptr(c) == b ) {
952 /* We just loaded the value from the same memory, i.e., the store
953 doesn't change the memory -- a write after read. */
954 a = get_Store_mem(n);
955 turn_into_tuple(n, 2);
956 set_Tuple_pred(n, pn_Store_M, a);
957 set_Tuple_pred(n, pn_Store_X_except, new_Bad()); DBG_OPT_WAR;
962 static ir_node *equivalent_node_Proj(ir_node *n)
966 ir_node *a = get_Proj_pred(n);
968 if ( get_irn_op(a) == op_Tuple) {
969 /* Remove the Tuple/Proj combination. */
970 if ( get_Proj_proj(n) <= get_Tuple_n_preds(a) ) {
971 n = get_Tuple_pred(a, get_Proj_proj(n)); DBG_OPT_TUPLE;
973 assert(0); /* This should not happen! */
975 //dump_ir_block_graph(current_ir_graph, "-CRASH");
976 //printf(">>>%d\n", get_irn_node_nr(n));
979 } else if (get_irn_mode(n) == mode_X &&
980 is_Bad(get_nodes_block(n))) {
981 /* Remove dead control flow -- early gigo. */
990 static ir_node *equivalent_node_Id(ir_node *n)
994 n = follow_Id(n); DBG_OPT_ID;
999 case iro_Mod, Quot, DivMod
1000 DivMod allocates new nodes --> it's treated in transform node.
1001 What about Quot, DivMod?
1005 * equivalent_node() returns a node equivalent to input n. It skips all nodes that
1006 * perform no actual computation, as, e.g., the Id nodes. It does not create
1007 * new nodes. It is therefore safe to free n if the node returned is not n.
1008 * If a node returns a Tuple we can not just skip it. If the size of the
1009 * in array fits, we transform n into a tuple (e.g., Div).
1012 equivalent_node(ir_node *n)
1014 if (n->op->equivalent_node)
1015 return n->op->equivalent_node(n);
1020 * set the default equivalent node operation
1022 static ir_op *firm_set_default_equivalent_node(ir_op *op)
1026 op->equivalent_node = equivalent_node_##a; \
1048 CASE(Load); /* dangerous */
1049 CASE(Store); /* dangerous, see todo */
1053 op->equivalent_node = NULL;
1061 * Do node specific optimizations of nodes predecessors.
1064 optimize_preds(ir_node *n) {
1065 ir_node *a = NULL, *b = NULL;
1067 /* get the operands we will work on for simple cases. */
1069 a = get_binop_left(n);
1070 b = get_binop_right(n);
1071 } else if (is_unop(n)) {
1075 switch (get_irn_opcode(n)) {
1078 /* We don't want Cast as input to Cmp. */
1079 if (get_irn_op(a) == op_Cast) {
1083 if (get_irn_op(b) == op_Cast) {
1085 set_Cmp_right(n, b);
1093 static ir_node *transform_node_Div(ir_node *n)
1095 tarval *tv = computed_value(n);
1097 /* BEWARE: it is NOT possible to optimize a/a to 1, as this may cause a exception */
1099 if (tv != tarval_bad) {
1100 /* Turn Div into a tuple (mem, bad, value) */
1101 ir_node *mem = get_Div_mem(n);
1103 turn_into_tuple(n, 3);
1104 set_Tuple_pred(n, pn_Div_M, mem);
1105 set_Tuple_pred(n, pn_Div_X_except, new_Bad());
1106 set_Tuple_pred(n, pn_Div_res, new_Const(get_tarval_mode(tv), tv));
1111 static ir_node *transform_node_Mod(ir_node *n)
1113 tarval *tv = computed_value(n);
1115 /* BEWARE: it is NOT possible to optimize a%a to 0, as this may cause a exception */
1117 if (tv != tarval_bad) {
1118 /* Turn Mod into a tuple (mem, bad, value) */
1119 ir_node *mem = get_Mod_mem(n);
1120 turn_into_tuple(n, 3);
1121 set_Tuple_pred(n, pn_Mod_M, mem);
1122 set_Tuple_pred(n, pn_Mod_X_except, new_Bad());
1123 set_Tuple_pred(n, pn_Mod_res, new_Const(get_tarval_mode(tv), tv));
1128 static ir_node *transform_node_DivMod(ir_node *n)
1132 ir_node *a = get_DivMod_left(n);
1133 ir_node *b = get_DivMod_right(n);
1134 ir_mode *mode = get_irn_mode(a);
1135 tarval *ta = value_of(a);
1136 tarval *tb = value_of(b);
1138 if (!(mode_is_int(mode) && mode_is_int(get_irn_mode(b))))
1141 /* BEWARE: it is NOT possible to optimize a/a to 1, as this may cause a exception */
1143 if (tb != tarval_bad) {
1144 if (tb == get_mode_one(get_tarval_mode(tb))) {
1145 b = new_Const (mode, get_mode_null(mode));
1147 } else if (ta != tarval_bad) {
1148 tarval *resa, *resb;
1149 resa = tarval_div (ta, tb);
1150 if (resa == tarval_bad) return n; /* Causes exception!!! Model by replacing through
1151 Jmp for X result!? */
1152 resb = tarval_mod (ta, tb);
1153 if (resb == tarval_bad) return n; /* Causes exception! */
1154 a = new_Const (mode, resa);
1155 b = new_Const (mode, resb);
1158 } else if (ta == get_mode_null(mode)) {
1162 if (evaluated) { /* replace by tuple */
1163 ir_node *mem = get_DivMod_mem(n);
1164 turn_into_tuple(n, 4);
1165 set_Tuple_pred(n, pn_DivMod_M, mem);
1166 set_Tuple_pred(n, pn_DivMod_X_except, new_Bad()); /* no exception */
1167 set_Tuple_pred(n, pn_DivMod_res_div, a);
1168 set_Tuple_pred(n, pn_DivMod_res_mod, b);
1169 assert(get_nodes_block(n));
1175 static ir_node *transform_node_Cond(ir_node *n)
1177 /* Replace the Cond by a Jmp if it branches on a constant
1180 ir_node *a = get_Cond_selector(n);
1181 tarval *ta = value_of(a);
1183 if ((ta != tarval_bad) &&
1184 (get_irn_mode(a) == mode_b) &&
1185 (get_opt_unreachable_code())) {
1186 /* It's a boolean Cond, branching on a boolean constant.
1187 Replace it by a tuple (Bad, Jmp) or (Jmp, Bad) */
1188 jmp = new_r_Jmp(current_ir_graph, get_nodes_block(n));
1189 turn_into_tuple(n, 2);
1190 if (ta == tarval_b_true) {
1191 set_Tuple_pred(n, pn_Cond_false, new_Bad());
1192 set_Tuple_pred(n, pn_Cond_true, jmp);
1194 set_Tuple_pred(n, pn_Cond_false, jmp);
1195 set_Tuple_pred(n, pn_Cond_true, new_Bad());
1197 /* We might generate an endless loop, so keep it alive. */
1198 add_End_keepalive(get_irg_end(current_ir_graph), get_nodes_block(n));
1199 } else if ((ta != tarval_bad) &&
1200 (get_irn_mode(a) == mode_Iu) &&
1201 (get_Cond_kind(n) == dense) &&
1202 (get_opt_unreachable_code())) {
1203 /* I don't want to allow Tuples smaller than the biggest Proj.
1204 Also this tuple might get really big...
1205 I generate the Jmp here, and remember it in link. Link is used
1206 when optimizing Proj. */
1207 set_irn_link(n, new_r_Jmp(current_ir_graph, get_nodes_block(n)));
1208 /* We might generate an endless loop, so keep it alive. */
1209 add_End_keepalive(get_irg_end(current_ir_graph), get_nodes_block(n));
1210 } else if ((get_irn_op(a) == op_Eor)
1211 && (get_irn_mode(a) == mode_b)
1212 && (classify_tarval(computed_value(get_Eor_right(a))) == TV_CLASSIFY_ONE)) {
1213 /* The Eor is a negate. Generate a new Cond without the negate,
1214 simulate the negate by exchanging the results. */
1215 set_irn_link(n, new_r_Cond(current_ir_graph, get_nodes_block(n),
1217 } else if ((get_irn_op(a) == op_Not)
1218 && (get_irn_mode(a) == mode_b)) {
1219 /* A Not before the Cond. Generate a new Cond without the Not,
1220 simulate the Not by exchanging the results. */
1221 set_irn_link(n, new_r_Cond(current_ir_graph, get_nodes_block(n),
1227 static ir_node *transform_node_Eor(ir_node *n)
1229 ir_node *a = get_Eor_left(n);
1230 ir_node *b = get_Eor_right(n);
1232 if ((get_irn_mode(n) == mode_b)
1233 && (get_irn_op(a) == op_Proj)
1234 && (get_irn_mode(a) == mode_b)
1235 && (classify_tarval (computed_value (b)) == TV_CLASSIFY_ONE)
1236 && (get_irn_op(get_Proj_pred(a)) == op_Cmp))
1237 /* The Eor negates a Cmp. The Cmp has the negated result anyways! */
1238 n = new_r_Proj(current_ir_graph, get_nodes_block(n), get_Proj_pred(a),
1239 mode_b, get_negated_pnc(get_Proj_proj(a)));
1240 else if ((get_irn_mode(n) == mode_b)
1241 && (classify_tarval (computed_value (b)) == TV_CLASSIFY_ONE))
1242 /* The Eor is a Not. Replace it by a Not. */
1243 /* ????!!!Extend to bitfield 1111111. */
1244 n = new_r_Not(current_ir_graph, get_nodes_block(n), a, mode_b);
1250 * Transfor a boolean Not.
1252 static ir_node *transform_node_Not(ir_node *n)
1254 ir_node *a = get_Not_op(n);
1256 if ( (get_irn_mode(n) == mode_b)
1257 && (get_irn_op(a) == op_Proj)
1258 && (get_irn_mode(a) == mode_b)
1259 && (get_irn_op(get_Proj_pred(a)) == op_Cmp))
1260 /* We negate a Cmp. The Cmp has the negated result anyways! */
1261 n = new_r_Proj(current_ir_graph, get_nodes_block(n), get_Proj_pred(a),
1262 mode_b, get_negated_pnc(get_Proj_proj(a)));
1268 * Transform a Div/Mod/DivMod with a non-zero constant. Must be
1269 * done here to avoid that this optimization runs more than once...
1271 static ir_node *transform_node_Proj(ir_node *proj)
1273 ir_node *n = get_Proj_pred(proj);
1277 switch (get_irn_opcode(n)) {
1279 b = get_Div_right(n);
1280 tb = computed_value(b);
1282 if (tb != tarval_bad && classify_tarval(tb) != TV_CLASSIFY_NULL) { /* div(x, c) && c != 0 */
1283 ir_node *div, *proj;
1284 ir_node *a = get_Div_left(n);
1285 ir_node *mem = get_Div_mem(n);
1286 int rem = get_optimize();
1290 div = new_rd_Div(get_irn_dbg_info(n), current_ir_graph,
1291 get_nodes_block(n), get_irg_initial_mem(current_ir_graph), a, b);
1293 proj = new_r_Proj(current_ir_graph, get_nodes_block(n), div, get_irn_mode(a), pn_Div_res);
1297 turn_into_tuple(n, 3);
1298 set_Tuple_pred(n, pn_Mod_M, mem);
1299 set_Tuple_pred(n, pn_Mod_X_except, new_Bad());
1300 set_Tuple_pred(n, pn_Mod_res, proj);
1304 b = get_Mod_right(n);
1305 tb = computed_value(b);
1307 if (tb != tarval_bad && classify_tarval(tb) != TV_CLASSIFY_NULL) { /* mod(x, c) && c != 0 */
1308 ir_node *mod, *proj;
1309 ir_node *a = get_Mod_left(n);
1310 ir_node *mem = get_Mod_mem(n);
1311 int rem = get_optimize();
1315 mod = new_rd_Mod(get_irn_dbg_info(n), current_ir_graph,
1316 get_nodes_block(n), get_irg_initial_mem(current_ir_graph), a, b);
1318 proj = new_r_Proj(current_ir_graph, get_nodes_block(n), mod, get_irn_mode(a), pn_Mod_res);
1322 turn_into_tuple(n, 3);
1323 set_Tuple_pred(n, pn_Mod_M, mem);
1324 set_Tuple_pred(n, pn_Mod_X_except, new_Bad());
1325 set_Tuple_pred(n, pn_Mod_res, proj);
1329 b = get_DivMod_right(n);
1330 tb = computed_value(b);
1332 if (tb != tarval_bad && classify_tarval(tb) != TV_CLASSIFY_NULL) { /* DivMod(x, c) && c != 0 */
1333 ir_node *div_mod, *proj_div, *proj_mod;
1334 ir_node *a = get_Mod_left(n);
1335 ir_node *mem = get_Mod_mem(n);
1336 int rem = get_optimize();
1340 div_mod = new_rd_DivMod(get_irn_dbg_info(n), current_ir_graph,
1341 get_nodes_block(n), get_irg_initial_mem(current_ir_graph), a, b);
1343 proj_div = new_r_Proj(current_ir_graph, get_nodes_block(n), div_mod, get_irn_mode(a), pn_DivMod_res_div);
1344 proj_mod = new_r_Proj(current_ir_graph, get_nodes_block(n), div_mod, get_irn_mode(a), pn_DivMod_res_mod);
1348 turn_into_tuple(n, 4);
1349 set_Tuple_pred(n, pn_DivMod_M, mem);
1350 set_Tuple_pred(n, pn_DivMod_X_except, new_Bad());
1351 set_Tuple_pred(n, pn_DivMod_res_div, proj_div);
1352 set_Tuple_pred(n, pn_DivMod_res_mod, proj_mod);
1357 if (get_opt_unreachable_code()) {
1358 b = get_Cond_selector(n);
1359 tb = computed_value(b);
1361 if (tb != tarval_bad && mode_is_int(get_tarval_mode(tb))) {
1362 /* we have a constant switch */
1363 long num = get_Proj_proj(proj);
1365 if (num != get_Cond_defaultProj(n)) { /* we cannot optimize default Proj's yet */
1366 if (get_tarval_long(tb) == num) {
1367 /* Do NOT create a jump here, or we will have 2 control flow ops
1368 * in a block. This case is optimized away in optimize_cf(). */
1383 /* we have added a Tuple, optimize it for the current Proj away */
1384 return equivalent_node_Proj(proj);
1388 * Transform a Store before a Store to the same address...
1389 * Both nodes must be in the same block.
1391 * @todo Check for volatile! Moreover, what if the first store
1392 * has a exception handler while the other has not?
1394 static ir_node *transform_node_Store(ir_node *store)
1396 ir_node *pred = skip_Proj(get_Store_mem(store));
1397 ir_node *ptr = get_Store_ptr(store);
1399 if (!get_opt_redundant_LoadStore()) return store;
1401 if (get_irn_op(pred) == op_Store &&
1402 get_Store_ptr(pred) == ptr &&
1403 get_nodes_block(pred) == get_nodes_block(store)) {
1404 /* the Store n is useless, as it is overwritten by the store store */
1405 ir_node *mem = get_Store_mem(pred);
1407 turn_into_tuple(pred, 2);
1408 set_Tuple_pred(pred, pn_Store_M, mem);
1409 set_Tuple_pred(pred, pn_Store_X_except, new_Bad());
1415 * returns the operands of a commutative bin-op, if one operand is
1416 * a const, it is returned as the second one.
1418 static void get_comm_Binop_Ops(ir_node *binop, ir_node **a, ir_node **c)
1420 ir_node *op_a = get_binop_left(binop);
1421 ir_node *op_b = get_binop_right(binop);
1423 assert(is_op_commutative(get_irn_op(binop)));
1425 if (get_irn_op(op_a) == op_Const) {
1436 * Optimize a Or(And(Or(And(v,c4),c3),c2),c1) pattern if possible.
1437 * Such pattern may arise in bitfield stores.
1439 * value c4 value c4 & c2
1440 * AND c3 AND c1 | c3
1445 static ir_node *transform_node_Or(ir_node *or)
1449 ir_node *and_l, *c3;
1450 ir_node *value, *c4;
1451 ir_node *new_and, *new_const, *block;
1452 ir_mode *mode = get_irn_mode(or);
1454 tarval *tv1, *tv2, *tv3, *tv4, *tv, *n_tv4, *n_tv2;
1456 get_comm_Binop_Ops(or, &and, &c1);
1457 if ((get_irn_op(c1) != op_Const) || (get_irn_op(and) != op_And))
1460 get_comm_Binop_Ops(and, &or_l, &c2);
1461 if ((get_irn_op(c2) != op_Const) || (get_irn_op(or_l) != op_Or))
1464 get_comm_Binop_Ops(or_l, &and_l, &c3);
1465 if ((get_irn_op(c3) != op_Const) || (get_irn_op(and_l) != op_And))
1468 get_comm_Binop_Ops(and_l, &value, &c4);
1469 if (get_irn_op(c4) != op_Const)
1472 /* ok, found the pattern, check for conditions */
1473 assert(mode == get_irn_mode(and));
1474 assert(mode == get_irn_mode(or_l));
1475 assert(mode == get_irn_mode(and_l));
1477 tv1 = get_Const_tarval(c1);
1478 tv2 = get_Const_tarval(c2);
1479 tv3 = get_Const_tarval(c3);
1480 tv4 = get_Const_tarval(c4);
1482 tv = tarval_or(tv4, tv2);
1483 if (classify_tarval(tv) != TV_CLASSIFY_ALL_ONE) {
1484 /* have at least one 0 at the same bit position */
1488 n_tv4 = tarval_not(tv4);
1489 if (tv3 != tarval_and(tv3, n_tv4)) {
1490 /* bit in the or_mask is outside the and_mask */
1494 n_tv2 = tarval_not(tv2);
1495 if (tv1 != tarval_and(tv1, n_tv2)) {
1496 /* bit in the or_mask is outside the and_mask */
1500 /* ok, all conditions met */
1501 block = get_nodes_block(or);
1503 new_and = new_r_And(current_ir_graph, block,
1504 value, new_r_Const(current_ir_graph, block, mode, tarval_and(tv4, tv2)), mode);
1506 new_const = new_r_Const(current_ir_graph, block, mode, tarval_or(tv3, tv1));
1508 set_Or_left(or, new_and);
1509 set_Or_right(or, new_const);
1511 /* check for more */
1512 return transform_node_Or(or);
1516 * Tries several [inplace] [optimizing] transformations and returns an
1517 * equivalent node. The difference to equivalent_node() is that these
1518 * transformations _do_ generate new nodes, and thus the old node must
1519 * not be freed even if the equivalent node isn't the old one.
1521 static ir_node *transform_node(ir_node *n)
1523 if (n->op->transform_node)
1524 n = n->op->transform_node(n);
1529 * set the default transform node operation
1531 static ir_op *firm_set_default_transform_node(ir_op *op)
1535 op->transform_node = transform_node_##a; \
1546 CASE(Store); /* dangerous, see todo */
1549 op->transform_node = NULL;
1557 /* **************** Common Subexpression Elimination **************** */
1559 /** The size of the hash table used, should estimate the number of nodes
1561 #define N_IR_NODES 512
1563 static int node_cmp_attr_Const(ir_node *a, ir_node *b)
1565 return (get_Const_tarval(a) != get_Const_tarval(b))
1566 || (get_Const_type(a) != get_Const_type(b));
1569 static int node_cmp_attr_Proj(ir_node *a, ir_node *b)
1571 return get_irn_proj_attr (a) != get_irn_proj_attr (b);
1574 static int node_cmp_attr_Filter(ir_node *a, ir_node *b)
1576 return get_Filter_proj(a) != get_Filter_proj(b);
1579 static int node_cmp_attr_Alloc(ir_node *a, ir_node *b)
1581 return (get_irn_alloc_attr(a).where != get_irn_alloc_attr(b).where)
1582 || (get_irn_alloc_attr(a).type != get_irn_alloc_attr(b).type);
1585 static int node_cmp_attr_Free(ir_node *a, ir_node *b)
1587 return (get_irn_free_attr(a) != get_irn_free_attr(b));
1590 static int node_cmp_attr_SymConst(ir_node *a, ir_node *b)
1592 return (get_irn_symconst_attr(a).num != get_irn_symconst_attr(b).num)
1593 || (get_irn_symconst_attr(a).sym.type_p != get_irn_symconst_attr(b).sym.type_p);
1596 static int node_cmp_attr_Call(ir_node *a, ir_node *b)
1598 return (get_irn_call_attr(a) != get_irn_call_attr(b));
1601 static int node_cmp_attr_FuncCall(ir_node *a, ir_node *b)
1603 return (get_irn_funccall_attr(a) != get_irn_funccall_attr(b));
1606 static int node_cmp_attr_Sel(ir_node *a, ir_node *b)
1608 return (get_irn_sel_attr(a).ent->kind != get_irn_sel_attr(b).ent->kind)
1609 || (get_irn_sel_attr(a).ent->name != get_irn_sel_attr(b).ent->name)
1610 || (get_irn_sel_attr(a).ent->owner != get_irn_sel_attr(b).ent->owner)
1611 || (get_irn_sel_attr(a).ent->ld_name != get_irn_sel_attr(b).ent->ld_name)
1612 || (get_irn_sel_attr(a).ent->type != get_irn_sel_attr(b).ent->type);
1615 static int node_cmp_attr_Phi(ir_node *a, ir_node *b)
1617 return get_irn_phi_attr (a) != get_irn_phi_attr (b);
1620 static int node_cmp_attr_Cast(ir_node *a, ir_node *b)
1622 return get_Cast_type(a) != get_Cast_type(b);
1626 * set the default node attribute compare operation
1628 static ir_op *firm_set_default_node_cmp_attr(ir_op *op)
1632 op->node_cmp_attr = node_cmp_attr_##a; \
1648 op->node_cmp_attr = NULL;
1656 * Compare function for two nodes in the hash table. Gets two
1657 * nodes as parameters. Returns 0 if the nodes are a cse.
1660 vt_cmp (const void *elt, const void *key)
1668 if (a == b) return 0;
1670 if ((get_irn_op(a) != get_irn_op(b)) ||
1671 (get_irn_mode(a) != get_irn_mode(b))) return 1;
1673 /* compare if a's in and b's in are equal */
1674 irn_arity_a = get_irn_arity (a);
1675 if (irn_arity_a != get_irn_arity(b))
1678 /* for block-local cse and op_pin_state_pinned nodes: */
1679 if (!get_opt_global_cse() || (get_op_pinned(get_irn_op(a)) == op_pin_state_pinned)) {
1680 if (get_irn_n(a, -1) != get_irn_n(b, -1))
1684 /* compare a->in[0..ins] with b->in[0..ins] */
1685 for (i = 0; i < irn_arity_a; i++)
1686 if (get_irn_n(a, i) != get_irn_n(b, i))
1690 * here, we already now that the nodes are identical except their
1693 if (a->op->node_cmp_attr)
1694 return a->op->node_cmp_attr(a, b);
1700 * Calculate a hash value of a node.
1703 ir_node_hash (ir_node *node)
1708 if (node->op == op_Const) {
1709 /* special value for const, as they only differ in their tarval. */
1710 h = ((unsigned) node->attr.con.tv)>>3 ;
1711 h = 9*h + (unsigned)get_irn_mode(node);
1712 } else if (node->op == op_SymConst) {
1713 /* special value for const, as they only differ in their symbol. */
1714 h = ((unsigned) node->attr.i.sym.type_p)>>3 ;
1715 h = 9*h + (unsigned)get_irn_mode(node);
1718 /* hash table value = 9*(9*(9*(9*(9*arity+in[0])+in[1])+ ...)+mode)+code */
1719 h = irn_arity = get_irn_arity(node);
1721 /* consider all in nodes... except the block. */
1722 for (i = 0; i < irn_arity; i++) {
1723 h = 9*h + (unsigned)get_irn_n(node, i);
1727 h = 9*h + (unsigned) get_irn_mode (node);
1729 h = 9*h + (unsigned) get_irn_op (node);
1736 new_identities (void)
1738 return new_pset (vt_cmp, N_IR_NODES);
1742 del_identities (pset *value_table)
1744 del_pset (value_table);
1748 * Return the canonical node computing the same value as n.
1749 * Looks up the node in a hash table.
1751 * For Const nodes this is performed in the constructor, too. Const
1752 * nodes are extremely time critical because of their frequent use in
1753 * constant string arrays.
1755 static INLINE ir_node *
1756 identify (pset *value_table, ir_node *n)
1760 if (!value_table) return n;
1762 /* TODO: use a generic commutative attribute */
1763 if (get_opt_reassociation()) {
1764 if (is_op_commutative(get_irn_op(n))) {
1765 /* for commutative operators perform a OP b == b OP a */
1766 if (get_binop_left(n) > get_binop_right(n)) {
1767 ir_node *h = get_binop_left(n);
1768 set_binop_left(n, get_binop_right(n));
1769 set_binop_right(n, h);
1774 o = pset_find (value_table, n, ir_node_hash (n));
1781 * During construction we set the op_pin_state_pinned flag in the graph right when the
1782 * optimization is performed. The flag turning on procedure global cse could
1783 * be changed between two allocations. This way we are safe.
1785 static INLINE ir_node *
1786 identify_cons (pset *value_table, ir_node *n) {
1788 n = identify(value_table, n);
1789 if (get_irn_n(old, -1) != get_irn_n(n, -1))
1790 set_irg_pinned(current_ir_graph, op_pin_state_floats);
1795 * Return the canonical node computing the same value as n.
1796 * Looks up the node in a hash table, enters it in the table
1797 * if it isn't there yet.
1800 identify_remember (pset *value_table, ir_node *node)
1804 if (!value_table) return node;
1806 /* lookup or insert in hash table with given hash key. */
1807 o = pset_insert (value_table, node, ir_node_hash (node));
1809 if (o == node) return node;
1815 add_identities (pset *value_table, ir_node *node) {
1816 identify_remember (value_table, node);
1820 * garbage in, garbage out. If a node has a dead input, i.e., the
1821 * Bad node is input to the node, return the Bad node.
1823 static INLINE ir_node *
1824 gigo (ir_node *node)
1827 ir_op* op = get_irn_op(node);
1829 /* remove garbage blocks by looking at control flow that leaves the block
1830 and replacing the control flow by Bad. */
1831 if (get_irn_mode(node) == mode_X) {
1832 ir_node *block = get_nodes_block(node);
1833 if (op == op_End) return node; /* Don't optimize End, may have Bads. */
1834 if (get_irn_op(block) == op_Block && get_Block_matured(block)) {
1835 irn_arity = get_irn_arity(block);
1836 for (i = 0; i < irn_arity; i++) {
1837 if (!is_Bad(get_irn_n(block, i))) break;
1839 if (i == irn_arity) return new_Bad();
1843 /* Blocks, Phis and Tuples may have dead inputs, e.g., if one of the
1844 blocks predecessors is dead. */
1845 if ( op != op_Block && op != op_Phi && op != op_Tuple) {
1846 irn_arity = get_irn_arity(node);
1847 for (i = -1; i < irn_arity; i++) {
1848 if (is_Bad(get_irn_n(node, i))) {
1854 /* With this code we violate the agreement that local_optimize
1855 only leaves Bads in Block, Phi and Tuple nodes. */
1856 /* If Block has only Bads as predecessors it's garbage. */
1857 /* If Phi has only Bads as predecessors it's garbage. */
1858 if ((op == op_Block && get_Block_matured(node)) || op == op_Phi) {
1859 irn_arity = get_irn_arity(node);
1860 for (i = 0; i < irn_arity; i++) {
1861 if (!is_Bad(get_irn_n(node, i))) break;
1863 if (i == irn_arity) node = new_Bad();
1871 * These optimizations deallocate nodes from the obstack.
1872 * It can only be called if it is guaranteed that no other nodes
1873 * reference this one, i.e., right after construction of a node.
1876 optimize_node (ir_node *n)
1880 opcode iro = get_irn_opcode(n);
1882 /* Allways optimize Phi nodes: part of the construction. */
1883 if ((!get_opt_optimize()) && (iro != iro_Phi)) return n;
1885 /* constant expression evaluation / constant folding */
1886 if (get_opt_constant_folding()) {
1887 /* constants can not be evaluated */
1888 if (iro != iro_Const) {
1889 /* try to evaluate */
1890 tv = computed_value (n);
1891 if ((get_irn_mode(n) != mode_T) && (tv != tarval_bad)) {
1893 * we MUST copy the node here temparary, because it's still needed
1894 * for DBG_OPT_ALGSIM0
1896 int node_size = offsetof(ir_node, attr) + n->op->attr_size;
1897 ir_node *x = alloca(node_size);
1899 memcpy(x, n, node_size);
1902 /* evaluation was successful -- replace the node. */
1903 obstack_free (current_ir_graph->obst, n);
1904 n = new_Const (get_tarval_mode (tv), tv);
1911 /* remove unnecessary nodes */
1912 if (get_opt_constant_folding() ||
1913 (iro == iro_Phi) || /* always optimize these nodes. */
1915 (iro == iro_Proj) ||
1916 (iro == iro_Block) ) /* Flags tested local. */
1917 n = equivalent_node (n);
1919 optimize_preds(n); /* do node specific optimizations of nodes predecessors. */
1921 /** common subexpression elimination **/
1922 /* Checks whether n is already available. */
1923 /* The block input is used to distinguish different subexpressions. Right
1924 now all nodes are op_pin_state_pinned to blocks, i.e., the cse only finds common
1925 subexpressions within a block. */
1927 n = identify_cons (current_ir_graph->value_table, n);
1930 /* We found an existing, better node, so we can deallocate the old node. */
1931 obstack_free (current_ir_graph->obst, oldn);
1936 /* Some more constant expression evaluation that does not allow to
1938 iro = get_irn_opcode(n);
1939 if (get_opt_constant_folding() ||
1940 (iro == iro_Cond) ||
1941 (iro == iro_Proj)) /* Flags tested local. */
1942 n = transform_node (n);
1944 /* Remove nodes with dead (Bad) input.
1945 Run always for transformation induced Bads. */
1948 /* Now we have a legal, useful node. Enter it in hash table for cse */
1949 if (get_opt_cse() && (get_irn_opcode(n) != iro_Block)) {
1950 n = identify_remember (current_ir_graph->value_table, n);
1958 * These optimizations never deallocate nodes. This can cause dead
1959 * nodes lying on the obstack. Remove these by a dead node elimination,
1960 * i.e., a copying garbage collection.
1963 optimize_in_place_2 (ir_node *n)
1967 opcode iro = get_irn_opcode(n);
1969 if (!get_opt_optimize() && (get_irn_op(n) != op_Phi)) return n;
1971 /* if not optimize return n */
1974 /* Here this is possible. Why? */
1979 /* constant expression evaluation / constant folding */
1980 if (get_opt_constant_folding()) {
1981 /* constants can not be evaluated */
1982 if (iro != iro_Const) {
1983 /* try to evaluate */
1984 tv = computed_value (n);
1985 if ((get_irn_mode(n) != mode_T) && (tv != tarval_bad)) {
1986 /* evaluation was successful -- replace the node. */
1987 n = new_Const (get_tarval_mode (tv), tv);
1994 /* remove unnecessary nodes */
1995 /*if (get_opt_constant_folding()) */
1996 if (get_opt_constant_folding() ||
1997 (iro == iro_Phi) || /* always optimize these nodes. */
1998 (iro == iro_Id) || /* ... */
1999 (iro == iro_Proj) || /* ... */
2000 (iro == iro_Block) ) /* Flags tested local. */
2001 n = equivalent_node (n);
2003 optimize_preds(n); /* do node specific optimizations of nodes predecessors. */
2005 /** common subexpression elimination **/
2006 /* Checks whether n is already available. */
2007 /* The block input is used to distinguish different subexpressions. Right
2008 now all nodes are op_pin_state_pinned to blocks, i.e., the cse only finds common
2009 subexpressions within a block. */
2010 if (get_opt_cse()) {
2011 n = identify (current_ir_graph->value_table, n);
2014 /* Some more constant expression evaluation. */
2015 iro = get_irn_opcode(n);
2016 if (get_opt_constant_folding() ||
2017 (iro == iro_Cond) ||
2018 (iro == iro_Proj)) /* Flags tested local. */
2019 n = transform_node (n);
2021 /* Remove nodes with dead (Bad) input.
2022 Run always for transformation induced Bads. */
2025 /* Now we can verify the node, as it has no dead inputs any more. */
2028 /* Now we have a legal, useful node. Enter it in hash table for cse.
2029 Blocks should be unique anyways. (Except the successor of start:
2030 is cse with the start block!) */
2031 if (get_opt_cse() && (get_irn_opcode(n) != iro_Block))
2032 n = identify_remember (current_ir_graph->value_table, n);
2038 * Wrapper for external use, set proper status bits after optimization.
2041 optimize_in_place (ir_node *n)
2043 /* Handle graph state */
2044 assert(get_irg_phase_state(current_ir_graph) != phase_building);
2046 if (get_opt_global_cse())
2047 set_irg_pinned(current_ir_graph, op_pin_state_floats);
2048 if (get_irg_outs_state(current_ir_graph) == outs_consistent)
2049 set_irg_outs_inconsistent(current_ir_graph);
2050 /* Maybe we could also test whether optimizing the node can
2051 change the control graph. */
2052 if (get_irg_dom_state(current_ir_graph) == dom_consistent)
2053 set_irg_dom_inconsistent(current_ir_graph);
2054 return optimize_in_place_2 (n);
2058 * set the default ir op operations
2060 ir_op *firm_set_default_operations(ir_op *op)
2062 op = firm_set_default_computed_value(op);
2063 op = firm_set_default_equivalent_node(op);
2064 op = firm_set_default_transform_node(op);
2065 op = firm_set_default_node_cmp_attr(op);