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 /* remove unnecessary Load. */
908 ir_node *a = skip_Proj(get_Load_mem(n));
909 ir_node *b = get_Load_ptr(n);
912 /* TODO: check for volatile */
913 if (get_irn_op(a) == op_Store && get_Store_ptr(a) == b) {
914 /* We load immediately after a store -- a read after write. */
915 ir_node *mem = get_Load_mem(n);
917 c = get_Store_value(a);
918 turn_into_tuple(n, 3);
919 set_Tuple_pred(n, pn_Load_M, mem);
920 set_Tuple_pred(n, pn_Load_res, c);
921 set_Tuple_pred(n, pn_Load_X_except, new_Bad()); DBG_OPT_RAW;
927 * Optimize store after store and load atfter store.
929 * @todo FAILS for volatile entities
931 static ir_node *equivalent_node_Store(ir_node *n)
935 /* remove unnecessary store. */
936 ir_node *a = skip_Proj(get_Store_mem(n));
937 ir_node *b = get_Store_ptr(n);
938 ir_node *c = skip_Proj(get_Store_value(n));
940 if (get_irn_op(a) == op_Store
941 && get_Store_ptr(a) == b
942 && skip_Proj(get_Store_value(a)) == c) {
943 /* We have twice exactly the same store -- a write after write. */
945 } else if (get_irn_op(c) == op_Load
946 && (a == c || skip_Proj(get_Load_mem(c)) == a)
947 && get_Load_ptr(c) == b ) {
948 /* We just loaded the value from the same memory, i.e., the store
949 doesn't change the memory -- a write after read. */
950 a = get_Store_mem(n);
951 turn_into_tuple(n, 2);
952 set_Tuple_pred(n, pn_Store_M, a);
953 set_Tuple_pred(n, pn_Store_X_except, new_Bad()); DBG_OPT_WAR;
958 static ir_node *equivalent_node_Proj(ir_node *n)
962 ir_node *a = get_Proj_pred(n);
964 if ( get_irn_op(a) == op_Tuple) {
965 /* Remove the Tuple/Proj combination. */
966 if ( get_Proj_proj(n) <= get_Tuple_n_preds(a) ) {
967 n = get_Tuple_pred(a, get_Proj_proj(n)); DBG_OPT_TUPLE;
969 // assert(0); /* This should not happen! */
971 dump_ir_block_graph(current_ir_graph, "-CRASH");
972 printf(">>>%d\n", get_irn_node_nr(n));
975 } else if (get_irn_mode(n) == mode_X &&
976 is_Bad(get_nodes_block(n))) {
977 /* Remove dead control flow -- early gigo. */
986 static ir_node *equivalent_node_Id(ir_node *n)
990 n = follow_Id(n); DBG_OPT_ID;
995 case iro_Mod, Quot, DivMod
996 DivMod allocates new nodes --> it's treated in transform node.
997 What about Quot, DivMod?
1001 * equivalent_node() returns a node equivalent to input n. It skips all nodes that
1002 * perform no actual computation, as, e.g., the Id nodes. It does not create
1003 * new nodes. It is therefore safe to free n if the node returned is not n.
1004 * If a node returns a Tuple we can not just skip it. If the size of the
1005 * in array fits, we transform n into a tuple (e.g., Div).
1008 equivalent_node(ir_node *n)
1010 if (n->op->equivalent_node)
1011 return n->op->equivalent_node(n);
1016 * set the default equivalent node operation
1018 static ir_op *firm_set_default_equivalent_node(ir_op *op)
1022 op->equivalent_node = equivalent_node_##a; \
1044 CASE(Load); /* dangerous */
1045 CASE(Store); /* dangerous, see todo */
1049 op->equivalent_node = NULL;
1057 * Do node specific optimizations of nodes predecessors.
1060 optimize_preds(ir_node *n) {
1061 ir_node *a = NULL, *b = NULL;
1063 /* get the operands we will work on for simple cases. */
1065 a = get_binop_left(n);
1066 b = get_binop_right(n);
1067 } else if (is_unop(n)) {
1071 switch (get_irn_opcode(n)) {
1074 /* We don't want Cast as input to Cmp. */
1075 if (get_irn_op(a) == op_Cast) {
1079 if (get_irn_op(b) == op_Cast) {
1081 set_Cmp_right(n, b);
1089 static ir_node *transform_node_Div(ir_node *n)
1091 tarval *tv = computed_value(n);
1093 /* BEWARE: it is NOT possible to optimize a/a to 1, as this may cause a exception */
1095 if (tv != tarval_bad) {
1096 /* Turn Div into a tuple (mem, bad, value) */
1097 ir_node *mem = get_Div_mem(n);
1099 turn_into_tuple(n, 3);
1100 set_Tuple_pred(n, pn_Div_M, mem);
1101 set_Tuple_pred(n, pn_Div_X_except, new_Bad());
1102 set_Tuple_pred(n, pn_Div_res, new_Const(get_tarval_mode(tv), tv));
1107 static ir_node *transform_node_Mod(ir_node *n)
1109 tarval *tv = computed_value(n);
1111 /* BEWARE: it is NOT possible to optimize a%a to 0, as this may cause a exception */
1113 if (tv != tarval_bad) {
1114 /* Turn Mod into a tuple (mem, bad, value) */
1115 ir_node *mem = get_Mod_mem(n);
1116 turn_into_tuple(n, 3);
1117 set_Tuple_pred(n, pn_Mod_M, mem);
1118 set_Tuple_pred(n, pn_Mod_X_except, new_Bad());
1119 set_Tuple_pred(n, pn_Mod_res, new_Const(get_tarval_mode(tv), tv));
1124 static ir_node *transform_node_DivMod(ir_node *n)
1128 ir_node *a = get_DivMod_left(n);
1129 ir_node *b = get_DivMod_right(n);
1130 ir_mode *mode = get_irn_mode(a);
1131 tarval *ta = value_of(a);
1132 tarval *tb = value_of(b);
1134 if (!(mode_is_int(mode) && mode_is_int(get_irn_mode(b))))
1137 /* BEWARE: it is NOT possible to optimize a/a to 1, as this may cause a exception */
1139 if (tb != tarval_bad) {
1140 if (tb == get_mode_one(get_tarval_mode(tb))) {
1141 b = new_Const (mode, get_mode_null(mode));
1143 } else if (ta != tarval_bad) {
1144 tarval *resa, *resb;
1145 resa = tarval_div (ta, tb);
1146 if (resa == tarval_bad) return n; /* Causes exception!!! Model by replacing through
1147 Jmp for X result!? */
1148 resb = tarval_mod (ta, tb);
1149 if (resb == tarval_bad) return n; /* Causes exception! */
1150 a = new_Const (mode, resa);
1151 b = new_Const (mode, resb);
1154 } else if (ta == get_mode_null(mode)) {
1158 if (evaluated) { /* replace by tuple */
1159 ir_node *mem = get_DivMod_mem(n);
1160 turn_into_tuple(n, 4);
1161 set_Tuple_pred(n, pn_DivMod_M, mem);
1162 set_Tuple_pred(n, pn_DivMod_X_except, new_Bad()); /* no exception */
1163 set_Tuple_pred(n, pn_DivMod_res_div, a);
1164 set_Tuple_pred(n, pn_DivMod_res_mod, b);
1165 assert(get_nodes_block(n));
1171 static ir_node *transform_node_Cond(ir_node *n)
1173 /* Replace the Cond by a Jmp if it branches on a constant
1176 ir_node *a = get_Cond_selector(n);
1177 tarval *ta = value_of(a);
1179 if ((ta != tarval_bad) &&
1180 (get_irn_mode(a) == mode_b) &&
1181 (get_opt_unreachable_code())) {
1182 /* It's a boolean Cond, branching on a boolean constant.
1183 Replace it by a tuple (Bad, Jmp) or (Jmp, Bad) */
1184 jmp = new_r_Jmp(current_ir_graph, get_nodes_block(n));
1185 turn_into_tuple(n, 2);
1186 if (ta == tarval_b_true) {
1187 set_Tuple_pred(n, pn_Cond_false, new_Bad());
1188 set_Tuple_pred(n, pn_Cond_true, jmp);
1190 set_Tuple_pred(n, pn_Cond_false, jmp);
1191 set_Tuple_pred(n, pn_Cond_true, new_Bad());
1193 /* We might generate an endless loop, so keep it alive. */
1194 add_End_keepalive(get_irg_end(current_ir_graph), get_nodes_block(n));
1195 } else if ((ta != tarval_bad) &&
1196 (get_irn_mode(a) == mode_Iu) &&
1197 (get_Cond_kind(n) == dense) &&
1198 (get_opt_unreachable_code())) {
1199 /* I don't want to allow Tuples smaller than the biggest Proj.
1200 Also this tuple might get really big...
1201 I generate the Jmp here, and remember it in link. Link is used
1202 when optimizing Proj. */
1203 set_irn_link(n, new_r_Jmp(current_ir_graph, get_nodes_block(n)));
1204 /* We might generate an endless loop, so keep it alive. */
1205 add_End_keepalive(get_irg_end(current_ir_graph), get_nodes_block(n));
1206 } else if ((get_irn_op(a) == op_Eor)
1207 && (get_irn_mode(a) == mode_b)
1208 && (classify_tarval(computed_value(get_Eor_right(a))) == TV_CLASSIFY_ONE)) {
1209 /* The Eor is a negate. Generate a new Cond without the negate,
1210 simulate the negate by exchanging the results. */
1211 set_irn_link(n, new_r_Cond(current_ir_graph, get_nodes_block(n),
1213 } else if ((get_irn_op(a) == op_Not)
1214 && (get_irn_mode(a) == mode_b)) {
1215 /* A Not before the Cond. Generate a new Cond without the Not,
1216 simulate the Not by exchanging the results. */
1217 set_irn_link(n, new_r_Cond(current_ir_graph, get_nodes_block(n),
1223 static ir_node *transform_node_Eor(ir_node *n)
1225 ir_node *a = get_Eor_left(n);
1226 ir_node *b = get_Eor_right(n);
1228 if ((get_irn_mode(n) == mode_b)
1229 && (get_irn_op(a) == op_Proj)
1230 && (get_irn_mode(a) == mode_b)
1231 && (classify_tarval (computed_value (b)) == TV_CLASSIFY_ONE)
1232 && (get_irn_op(get_Proj_pred(a)) == op_Cmp))
1233 /* The Eor negates a Cmp. The Cmp has the negated result anyways! */
1234 n = new_r_Proj(current_ir_graph, get_nodes_block(n), get_Proj_pred(a),
1235 mode_b, get_negated_pnc(get_Proj_proj(a)));
1236 else if ((get_irn_mode(n) == mode_b)
1237 && (classify_tarval (computed_value (b)) == TV_CLASSIFY_ONE))
1238 /* The Eor is a Not. Replace it by a Not. */
1239 /* ????!!!Extend to bitfield 1111111. */
1240 n = new_r_Not(current_ir_graph, get_nodes_block(n), a, mode_b);
1246 * Transfor a boolean Not.
1248 static ir_node *transform_node_Not(ir_node *n)
1250 ir_node *a = get_Not_op(n);
1252 if ( (get_irn_mode(n) == mode_b)
1253 && (get_irn_op(a) == op_Proj)
1254 && (get_irn_mode(a) == mode_b)
1255 && (get_irn_op(get_Proj_pred(a)) == op_Cmp))
1256 /* We negate a Cmp. The Cmp has the negated result anyways! */
1257 n = new_r_Proj(current_ir_graph, get_nodes_block(n), get_Proj_pred(a),
1258 mode_b, get_negated_pnc(get_Proj_proj(a)));
1264 * Transform a Div/Mod/DivMod with a non-zero constant. Must be
1265 * done here to avoid that this optimization runs more than once...
1267 static ir_node *transform_node_Proj(ir_node *proj)
1269 ir_node *n = get_Proj_pred(proj);
1273 switch (get_irn_opcode(n)) {
1275 b = get_Div_right(n);
1276 tb = computed_value(b);
1278 if (tb != tarval_bad && classify_tarval(tb) != TV_CLASSIFY_NULL) { /* div(x, c) && c != 0 */
1279 ir_node *div, *proj;
1280 ir_node *a = get_Div_left(n);
1281 ir_node *mem = get_Div_mem(n);
1282 int rem = get_optimize();
1286 div = new_rd_Div(get_irn_dbg_info(n), current_ir_graph,
1287 get_nodes_block(n), get_irg_initial_mem(current_ir_graph), a, b);
1289 proj = new_r_Proj(current_ir_graph, get_nodes_block(n), div, get_irn_mode(a), pn_Div_res);
1293 turn_into_tuple(n, 3);
1294 set_Tuple_pred(n, pn_Mod_M, mem);
1295 set_Tuple_pred(n, pn_Mod_X_except, new_Bad());
1296 set_Tuple_pred(n, pn_Mod_res, proj);
1300 b = get_Mod_right(n);
1301 tb = computed_value(b);
1303 if (tb != tarval_bad && classify_tarval(tb) != TV_CLASSIFY_NULL) { /* mod(x, c) && c != 0 */
1304 ir_node *mod, *proj;
1305 ir_node *a = get_Mod_left(n);
1306 ir_node *mem = get_Mod_mem(n);
1307 int rem = get_optimize();
1311 mod = new_rd_Mod(get_irn_dbg_info(n), current_ir_graph,
1312 get_nodes_block(n), get_irg_initial_mem(current_ir_graph), a, b);
1314 proj = new_r_Proj(current_ir_graph, get_nodes_block(n), mod, get_irn_mode(a), pn_Mod_res);
1318 turn_into_tuple(n, 3);
1319 set_Tuple_pred(n, pn_Mod_M, mem);
1320 set_Tuple_pred(n, pn_Mod_X_except, new_Bad());
1321 set_Tuple_pred(n, pn_Mod_res, proj);
1325 b = get_DivMod_right(n);
1326 tb = computed_value(b);
1328 if (tb != tarval_bad && classify_tarval(tb) != TV_CLASSIFY_NULL) { /* DivMod(x, c) && c != 0 */
1329 ir_node *div_mod, *proj_div, *proj_mod;
1330 ir_node *a = get_Mod_left(n);
1331 ir_node *mem = get_Mod_mem(n);
1332 int rem = get_optimize();
1336 div_mod = new_rd_DivMod(get_irn_dbg_info(n), current_ir_graph,
1337 get_nodes_block(n), get_irg_initial_mem(current_ir_graph), a, b);
1339 proj_div = new_r_Proj(current_ir_graph, get_nodes_block(n), div_mod, get_irn_mode(a), pn_DivMod_res_div);
1340 proj_mod = new_r_Proj(current_ir_graph, get_nodes_block(n), div_mod, get_irn_mode(a), pn_DivMod_res_mod);
1344 turn_into_tuple(n, 4);
1345 set_Tuple_pred(n, pn_DivMod_M, mem);
1346 set_Tuple_pred(n, pn_DivMod_X_except, new_Bad());
1347 set_Tuple_pred(n, pn_DivMod_res_div, proj_div);
1348 set_Tuple_pred(n, pn_DivMod_res_mod, proj_mod);
1353 if (get_opt_unreachable_code()) {
1354 b = get_Cond_selector(n);
1355 tb = computed_value(b);
1357 if (tb != tarval_bad && mode_is_int(get_tarval_mode(tb))) {
1358 /* we have a constant switch */
1359 long num = get_Proj_proj(proj);
1361 if (num != get_Cond_defaultProj(n)) { /* we cannot optimize default Proj's yet */
1362 if (get_tarval_long(tb) == num) {
1363 /* Do NOT create a jump here, or we will have 2 control flow ops
1364 * in a block. This case is optimized away in optimize_cf(). */
1379 /* we have added a Tuple, optimize it for the current Proj away */
1380 return equivalent_node_Proj(proj);
1384 * Transform a Store before a Store to the same address...
1385 * Both nodes must be in the same block.
1387 * @todo Check for volatile! Moreover, what if the first store
1388 * has a exception handler while the other has not?
1390 static ir_node *transform_node_Store(ir_node *store)
1392 ir_node *pred = skip_Proj(get_Store_mem(store));
1393 ir_node *ptr = get_Store_ptr(store);
1395 if (get_irn_op(pred) == op_Store &&
1396 get_Store_ptr(pred) == ptr &&
1397 get_nodes_block(pred) == get_nodes_block(store)) {
1398 /* the Store n is useless, as it is overwritten by the store store */
1399 ir_node *mem = get_Store_mem(pred);
1401 turn_into_tuple(pred, 2);
1402 set_Tuple_pred(pred, pn_Store_M, mem);
1403 set_Tuple_pred(pred, pn_Store_X_except, new_Bad());
1409 * returns the operands of a commutative bin-op, if one operand is
1410 * a const, it is returned as the second one.
1412 static void get_comm_Binop_Ops(ir_node *binop, ir_node **a, ir_node **c)
1414 ir_node *op_a = get_binop_left(binop);
1415 ir_node *op_b = get_binop_right(binop);
1417 assert(is_op_commutative(get_irn_op(binop)));
1419 if (get_irn_op(op_a) == op_Const) {
1430 * Optimize a Or(And(Or(And(v,c4),c3),c2),c1) pattern if possible.
1431 * Such pattern may arise in bitfield stores.
1433 * value c4 value c4 & c2
1434 * AND c3 AND c1 | c3
1439 static ir_node *transform_node_Or(ir_node *or)
1443 ir_node *and_l, *c3;
1444 ir_node *value, *c4;
1445 ir_node *new_and, *new_const, *block;
1446 ir_mode *mode = get_irn_mode(or);
1448 tarval *tv1, *tv2, *tv3, *tv4, *tv, *n_tv4, *n_tv2;
1450 get_comm_Binop_Ops(or, &and, &c1);
1451 if ((get_irn_op(c1) != op_Const) || (get_irn_op(and) != op_And))
1454 get_comm_Binop_Ops(and, &or_l, &c2);
1455 if ((get_irn_op(c2) != op_Const) || (get_irn_op(or_l) != op_Or))
1458 get_comm_Binop_Ops(or_l, &and_l, &c3);
1459 if ((get_irn_op(c3) != op_Const) || (get_irn_op(and_l) != op_And))
1462 get_comm_Binop_Ops(and_l, &value, &c4);
1463 if (get_irn_op(c4) != op_Const)
1466 /* ok, found the pattern, check for conditions */
1467 assert(mode == get_irn_mode(and));
1468 assert(mode == get_irn_mode(or_l));
1469 assert(mode == get_irn_mode(and_l));
1471 tv1 = get_Const_tarval(c1);
1472 tv2 = get_Const_tarval(c2);
1473 tv3 = get_Const_tarval(c3);
1474 tv4 = get_Const_tarval(c4);
1476 tv = tarval_or(tv4, tv2);
1477 if (classify_tarval(tv) != TV_CLASSIFY_ALL_ONE) {
1478 /* have at least one 0 at the same bit position */
1482 n_tv4 = tarval_not(tv4);
1483 if (tv3 != tarval_and(tv3, n_tv4)) {
1484 /* bit in the or_mask is outside the and_mask */
1488 n_tv2 = tarval_not(tv2);
1489 if (tv1 != tarval_and(tv1, n_tv2)) {
1490 /* bit in the or_mask is outside the and_mask */
1494 /* ok, all conditions met */
1495 block = get_nodes_block(or);
1497 new_and = new_r_And(current_ir_graph, block,
1498 value, new_r_Const(current_ir_graph, block, mode, tarval_and(tv4, tv2)), mode);
1500 new_const = new_r_Const(current_ir_graph, block, mode, tarval_or(tv3, tv1));
1502 set_Or_left(or, new_and);
1503 set_Or_right(or, new_const);
1505 /* check for more */
1506 return transform_node_Or(or);
1510 * Tries several [inplace] [optimizing] transformations and returns an
1511 * equivalent node. The difference to equivalent_node() is that these
1512 * transformations _do_ generate new nodes, and thus the old node must
1513 * not be freed even if the equivalent node isn't the old one.
1515 static ir_node *transform_node(ir_node *n)
1517 if (n->op->transform_node)
1518 n = n->op->transform_node(n);
1523 * set the default transform node operation
1525 static ir_op *firm_set_default_transform_node(ir_op *op)
1529 op->transform_node = transform_node_##a; \
1540 CASE(Store); /* dangerous, see todo */
1543 op->transform_node = NULL;
1551 /* **************** Common Subexpression Elimination **************** */
1553 /** The size of the hash table used, should estimate the number of nodes
1555 #define N_IR_NODES 512
1557 static int node_cmp_attr_Const(ir_node *a, ir_node *b)
1559 return (get_Const_tarval(a) != get_Const_tarval(b))
1560 || (get_Const_type(a) != get_Const_type(b));
1563 static int node_cmp_attr_Proj(ir_node *a, ir_node *b)
1565 return get_irn_proj_attr (a) != get_irn_proj_attr (b);
1568 static int node_cmp_attr_Filter(ir_node *a, ir_node *b)
1570 return get_Filter_proj(a) != get_Filter_proj(b);
1573 static int node_cmp_attr_Alloc(ir_node *a, ir_node *b)
1575 return (get_irn_alloc_attr(a).where != get_irn_alloc_attr(b).where)
1576 || (get_irn_alloc_attr(a).type != get_irn_alloc_attr(b).type);
1579 static int node_cmp_attr_Free(ir_node *a, ir_node *b)
1581 return (get_irn_free_attr(a) != get_irn_free_attr(b));
1584 static int node_cmp_attr_SymConst(ir_node *a, ir_node *b)
1586 return (get_irn_symconst_attr(a).num != get_irn_symconst_attr(b).num)
1587 || (get_irn_symconst_attr(a).sym.type_p != get_irn_symconst_attr(b).sym.type_p);
1590 static int node_cmp_attr_Call(ir_node *a, ir_node *b)
1592 return (get_irn_call_attr(a) != get_irn_call_attr(b));
1595 static int node_cmp_attr_FuncCall(ir_node *a, ir_node *b)
1597 return (get_irn_funccall_attr(a) != get_irn_funccall_attr(b));
1600 static int node_cmp_attr_Sel(ir_node *a, ir_node *b)
1602 return (get_irn_sel_attr(a).ent->kind != get_irn_sel_attr(b).ent->kind)
1603 || (get_irn_sel_attr(a).ent->name != get_irn_sel_attr(b).ent->name)
1604 || (get_irn_sel_attr(a).ent->owner != get_irn_sel_attr(b).ent->owner)
1605 || (get_irn_sel_attr(a).ent->ld_name != get_irn_sel_attr(b).ent->ld_name)
1606 || (get_irn_sel_attr(a).ent->type != get_irn_sel_attr(b).ent->type);
1609 static int node_cmp_attr_Phi(ir_node *a, ir_node *b)
1611 return get_irn_phi_attr (a) != get_irn_phi_attr (b);
1614 static int node_cmp_attr_Cast(ir_node *a, ir_node *b)
1616 return get_Cast_type(a) != get_Cast_type(b);
1620 * set the default node attribute compare operation
1622 static ir_op *firm_set_default_node_cmp_attr(ir_op *op)
1626 op->node_cmp_attr = node_cmp_attr_##a; \
1642 op->node_cmp_attr = NULL;
1650 * Compare function for two nodes in the hash table. Gets two
1651 * nodes as parameters. Returns 0 if the nodes are a cse.
1654 vt_cmp (const void *elt, const void *key)
1662 if (a == b) return 0;
1664 if ((get_irn_op(a) != get_irn_op(b)) ||
1665 (get_irn_mode(a) != get_irn_mode(b))) return 1;
1667 /* compare if a's in and b's in are equal */
1668 irn_arity_a = get_irn_arity (a);
1669 if (irn_arity_a != get_irn_arity(b))
1672 /* for block-local cse and op_pin_state_pinned nodes: */
1673 if (!get_opt_global_cse() || (get_op_pinned(get_irn_op(a)) == op_pin_state_pinned)) {
1674 if (get_irn_n(a, -1) != get_irn_n(b, -1))
1678 /* compare a->in[0..ins] with b->in[0..ins] */
1679 for (i = 0; i < irn_arity_a; i++)
1680 if (get_irn_n(a, i) != get_irn_n(b, i))
1684 * here, we already now that the nodes are identical except their
1687 if (a->op->node_cmp_attr)
1688 return a->op->node_cmp_attr(a, b);
1694 * Calculate a hash value of a node.
1697 ir_node_hash (ir_node *node)
1702 if (node->op == op_Const) {
1703 /* special value for const, as they only differ in their tarval. */
1704 h = ((unsigned) node->attr.con.tv)>>3 ;
1705 h = 9*h + (unsigned)get_irn_mode(node);
1706 } else if (node->op == op_SymConst) {
1707 /* special value for const, as they only differ in their symbol. */
1708 h = ((unsigned) node->attr.i.sym.type_p)>>3 ;
1709 h = 9*h + (unsigned)get_irn_mode(node);
1712 /* hash table value = 9*(9*(9*(9*(9*arity+in[0])+in[1])+ ...)+mode)+code */
1713 h = irn_arity = get_irn_arity(node);
1715 /* consider all in nodes... except the block. */
1716 for (i = 0; i < irn_arity; i++) {
1717 h = 9*h + (unsigned)get_irn_n(node, i);
1721 h = 9*h + (unsigned) get_irn_mode (node);
1723 h = 9*h + (unsigned) get_irn_op (node);
1730 new_identities (void)
1732 return new_pset (vt_cmp, N_IR_NODES);
1736 del_identities (pset *value_table)
1738 del_pset (value_table);
1742 * Return the canonical node computing the same value as n.
1743 * Looks up the node in a hash table.
1745 * For Const nodes this is performed in the constructor, too. Const
1746 * nodes are extremely time critical because of their frequent use in
1747 * constant string arrays.
1749 static INLINE ir_node *
1750 identify (pset *value_table, ir_node *n)
1754 if (!value_table) return n;
1756 /* TODO: use a generic commutative attribute */
1757 if (get_opt_reassociation()) {
1758 if (is_op_commutative(get_irn_op(n))) {
1759 /* for commutative operators perform a OP b == b OP a */
1760 if (get_binop_left(n) > get_binop_right(n)) {
1761 ir_node *h = get_binop_left(n);
1762 set_binop_left(n, get_binop_right(n));
1763 set_binop_right(n, h);
1768 o = pset_find (value_table, n, ir_node_hash (n));
1775 * During construction we set the op_pin_state_pinned flag in the graph right when the
1776 * optimization is performed. The flag turning on procedure global cse could
1777 * be changed between two allocations. This way we are safe.
1779 static INLINE ir_node *
1780 identify_cons (pset *value_table, ir_node *n) {
1782 n = identify(value_table, n);
1783 if (get_irn_n(old, -1) != get_irn_n(n, -1))
1784 set_irg_pinned(current_ir_graph, op_pin_state_floats);
1789 * Return the canonical node computing the same value as n.
1790 * Looks up the node in a hash table, enters it in the table
1791 * if it isn't there yet.
1794 identify_remember (pset *value_table, ir_node *node)
1798 if (!value_table) return node;
1800 /* lookup or insert in hash table with given hash key. */
1801 o = pset_insert (value_table, node, ir_node_hash (node));
1803 if (o == node) return node;
1809 add_identities (pset *value_table, ir_node *node) {
1810 identify_remember (value_table, node);
1814 * garbage in, garbage out. If a node has a dead input, i.e., the
1815 * Bad node is input to the node, return the Bad node.
1817 static INLINE ir_node *
1818 gigo (ir_node *node)
1821 ir_op* op = get_irn_op(node);
1823 /* remove garbage blocks by looking at control flow that leaves the block
1824 and replacing the control flow by Bad. */
1825 if (get_irn_mode(node) == mode_X) {
1826 ir_node *block = get_nodes_block(node);
1827 if (op == op_End) return node; /* Don't optimize End, may have Bads. */
1828 if (get_irn_op(block) == op_Block && get_Block_matured(block)) {
1829 irn_arity = get_irn_arity(block);
1830 for (i = 0; i < irn_arity; i++) {
1831 if (!is_Bad(get_irn_n(block, i))) break;
1833 if (i == irn_arity) return new_Bad();
1837 /* Blocks, Phis and Tuples may have dead inputs, e.g., if one of the
1838 blocks predecessors is dead. */
1839 if ( op != op_Block && op != op_Phi && op != op_Tuple) {
1840 irn_arity = get_irn_arity(node);
1841 for (i = -1; i < irn_arity; i++) {
1842 if (is_Bad(get_irn_n(node, i))) {
1848 /* With this code we violate the agreement that local_optimize
1849 only leaves Bads in Block, Phi and Tuple nodes. */
1850 /* If Block has only Bads as predecessors it's garbage. */
1851 /* If Phi has only Bads as predecessors it's garbage. */
1852 if ((op == op_Block && get_Block_matured(node)) || op == op_Phi) {
1853 irn_arity = get_irn_arity(node);
1854 for (i = 0; i < irn_arity; i++) {
1855 if (!is_Bad(get_irn_n(node, i))) break;
1857 if (i == irn_arity) node = new_Bad();
1865 * These optimizations deallocate nodes from the obstack.
1866 * It can only be called if it is guaranteed that no other nodes
1867 * reference this one, i.e., right after construction of a node.
1870 optimize_node (ir_node *n)
1874 opcode iro = get_irn_opcode(n);
1876 /* Allways optimize Phi nodes: part of the construction. */
1877 if ((!get_opt_optimize()) && (iro != iro_Phi)) return n;
1879 /* constant expression evaluation / constant folding */
1880 if (get_opt_constant_folding()) {
1881 /* constants can not be evaluated */
1882 if (iro != iro_Const) {
1883 /* try to evaluate */
1884 tv = computed_value (n);
1885 if ((get_irn_mode(n) != mode_T) && (tv != tarval_bad)) {
1887 * we MUST copy the node here temparary, because it's still needed
1888 * for DBG_OPT_ALGSIM0
1890 int node_size = offsetof(ir_node, attr) + n->op->attr_size;
1891 ir_node *x = alloca(node_size);
1893 memcpy(x, n, node_size);
1896 /* evaluation was successful -- replace the node. */
1897 obstack_free (current_ir_graph->obst, n);
1898 n = new_Const (get_tarval_mode (tv), tv);
1905 /* remove unnecessary nodes */
1906 if (get_opt_constant_folding() ||
1907 (iro == iro_Phi) || /* always optimize these nodes. */
1909 (iro == iro_Proj) ||
1910 (iro == iro_Block) ) /* Flags tested local. */
1911 n = equivalent_node (n);
1913 optimize_preds(n); /* do node specific optimizations of nodes predecessors. */
1915 /** common subexpression elimination **/
1916 /* Checks whether n is already available. */
1917 /* The block input is used to distinguish different subexpressions. Right
1918 now all nodes are op_pin_state_pinned to blocks, i.e., the cse only finds common
1919 subexpressions within a block. */
1921 n = identify_cons (current_ir_graph->value_table, n);
1924 /* We found an existing, better node, so we can deallocate the old node. */
1925 obstack_free (current_ir_graph->obst, oldn);
1930 /* Some more constant expression evaluation that does not allow to
1932 iro = get_irn_opcode(n);
1933 if (get_opt_constant_folding() ||
1934 (iro == iro_Cond) ||
1935 (iro == iro_Proj)) /* Flags tested local. */
1936 n = transform_node (n);
1938 /* Remove nodes with dead (Bad) input.
1939 Run always for transformation induced Bads. */
1942 /* Now we have a legal, useful node. Enter it in hash table for cse */
1943 if (get_opt_cse() && (get_irn_opcode(n) != iro_Block)) {
1944 n = identify_remember (current_ir_graph->value_table, n);
1952 * These optimizations never deallocate nodes. This can cause dead
1953 * nodes lying on the obstack. Remove these by a dead node elimination,
1954 * i.e., a copying garbage collection.
1957 optimize_in_place_2 (ir_node *n)
1961 opcode iro = get_irn_opcode(n);
1963 if (!get_opt_optimize() && (get_irn_op(n) != op_Phi)) return n;
1965 /* if not optimize return n */
1968 /* Here this is possible. Why? */
1973 /* constant expression evaluation / constant folding */
1974 if (get_opt_constant_folding()) {
1975 /* constants can not be evaluated */
1976 if (iro != iro_Const) {
1977 /* try to evaluate */
1978 tv = computed_value (n);
1979 if ((get_irn_mode(n) != mode_T) && (tv != tarval_bad)) {
1980 /* evaluation was successful -- replace the node. */
1981 n = new_Const (get_tarval_mode (tv), tv);
1988 /* remove unnecessary nodes */
1989 /*if (get_opt_constant_folding()) */
1990 if (get_opt_constant_folding() ||
1991 (iro == iro_Phi) || /* always optimize these nodes. */
1992 (iro == iro_Id) || /* ... */
1993 (iro == iro_Proj) || /* ... */
1994 (iro == iro_Block) ) /* Flags tested local. */
1995 n = equivalent_node (n);
1997 optimize_preds(n); /* do node specific optimizations of nodes predecessors. */
1999 /** common subexpression elimination **/
2000 /* Checks whether n is already available. */
2001 /* The block input is used to distinguish different subexpressions. Right
2002 now all nodes are op_pin_state_pinned to blocks, i.e., the cse only finds common
2003 subexpressions within a block. */
2004 if (get_opt_cse()) {
2005 n = identify (current_ir_graph->value_table, n);
2008 /* Some more constant expression evaluation. */
2009 iro = get_irn_opcode(n);
2010 if (get_opt_constant_folding() ||
2011 (iro == iro_Cond) ||
2012 (iro == iro_Proj)) /* Flags tested local. */
2013 n = transform_node (n);
2015 /* Remove nodes with dead (Bad) input.
2016 Run always for transformation induced Bads. */
2019 /* Now we can verify the node, as it has no dead inputs any more. */
2022 /* Now we have a legal, useful node. Enter it in hash table for cse.
2023 Blocks should be unique anyways. (Except the successor of start:
2024 is cse with the start block!) */
2025 if (get_opt_cse() && (get_irn_opcode(n) != iro_Block))
2026 n = identify_remember (current_ir_graph->value_table, n);
2032 * Wrapper for external use, set proper status bits after optimization.
2035 optimize_in_place (ir_node *n)
2037 /* Handle graph state */
2038 assert(get_irg_phase_state(current_ir_graph) != phase_building);
2040 if (get_opt_global_cse())
2041 set_irg_pinned(current_ir_graph, op_pin_state_floats);
2042 if (get_irg_outs_state(current_ir_graph) == outs_consistent)
2043 set_irg_outs_inconsistent(current_ir_graph);
2044 /* Maybe we could also test whether optimizing the node can
2045 change the control graph. */
2046 if (get_irg_dom_state(current_ir_graph) == dom_consistent)
2047 set_irg_dom_inconsistent(current_ir_graph);
2048 return optimize_in_place_2 (n);
2052 * set the default ir op operations
2054 ir_op *firm_set_default_operations(ir_op *op)
2056 op = firm_set_default_computed_value(op);
2057 op = firm_set_default_equivalent_node(op);
2058 op = firm_set_default_transform_node(op);
2059 op = firm_set_default_node_cmp_attr(op);