2 * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved.
4 * This file is part of libFirm.
6 * This file may be distributed and/or modified under the terms of the
7 * GNU General Public License version 2 as published by the Free Software
8 * Foundation and appearing in the file LICENSE.GPL included in the
9 * packaging of this file.
11 * Licensees holding valid libFirm Professional Edition licenses may use
12 * this file in accordance with the libFirm Commercial License.
13 * Agreement provided with the Software.
15 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
16 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * @brief boolean condition/controlflow optimisations
23 * @author Matthias Braun, Christoph Mallon
24 * @version $Id: cfopt.c 22579 2008-10-07 14:54:04Z beck $
40 typedef struct cond_pair {
51 static int find_cond_pair(ir_node *const l, ir_node *const r, cond_pair *const res)
53 if (is_Proj(l) && is_Proj(r)) {
54 ir_node *const lo = get_Proj_pred(l);
55 ir_node *const ro = get_Proj_pred(r);
57 if (is_Cmp(lo) && is_Cmp(ro)) {
58 ir_node *const lol = get_Cmp_left(lo);
59 ir_node *const lor = get_Cmp_right(lo);
60 ir_node *const rol = get_Cmp_left(ro);
61 ir_node *const ror = get_Cmp_right(ro);
63 if(is_Const(lor) && is_Const_null(lor) && is_Const(ror) && is_Const_null(ror) && get_Proj_proj(l) == pn_Cmp_Lg && get_Proj_proj(r) == pn_Cmp_Lg) {
64 ir_fprintf(stderr, "found zero zero\n");
68 /* The constants shall be unequal. Local optimisations handle the
70 if (lol == rol && mode_is_int(get_irn_mode(lol)) && lor != ror && is_Const(lor) && is_Const(ror)) {
71 tarval *const tv_l = get_Const_tarval(lor);
72 tarval *const tv_r = get_Const_tarval(ror);
73 pn_Cmp const pnc_l = get_Proj_proj(l);
74 pn_Cmp const pnc_r = get_Proj_proj(r);
75 pn_Cmp const rel = tarval_cmp(tv_l, tv_r);
77 assert(rel != pn_Cmp_Eq);
79 if (rel == pn_Cmp_Lt) {
89 assert(rel == pn_Cmp_Gt);
106 static ir_node *bool_and(cond_pair* const cpair)
108 ir_node *const cmp_lo = cpair->cmp_lo;
109 ir_node *const cmp_hi = cpair->cmp_hi;
110 pn_Cmp const pnc_lo = cpair->pnc_lo;
111 pn_Cmp const pnc_hi = cpair->pnc_hi;
112 ir_node *const proj_lo = cpair->proj_lo;
113 ir_node *const proj_hi = cpair->proj_hi;
114 tarval *const tv_lo = cpair->tv_lo;
115 tarval *const tv_hi = cpair->tv_hi;
117 /* Beware of NaN's, we can only check for (ordered) != here (which is Lg, not Ne) */
118 if ((pnc_lo == pn_Cmp_Lt || pnc_lo == pn_Cmp_Le || pnc_lo == pn_Cmp_Eq) &&
119 (pnc_hi == pn_Cmp_Eq || pnc_hi == pn_Cmp_Ge || pnc_hi == pn_Cmp_Gt)) {
120 /* x <|<=|== lo | x ==|>=|> hi -> false */
121 ir_node *const t = new_Const(tarval_b_false);
123 } else if ((pnc_lo == pn_Cmp_Lt || pnc_lo == pn_Cmp_Le || pnc_lo == pn_Cmp_Eq) &&
124 (pnc_hi == pn_Cmp_Lt || pnc_hi == pn_Cmp_Le || pnc_hi == pn_Cmp_Lg)) {
125 /* x <|<=|== lo && x <|<=|!= hi -> x <|<=|== lo */
127 } else if ((pnc_lo == pn_Cmp_Ge || pnc_lo == pn_Cmp_Gt || pnc_lo == pn_Cmp_Lg) &&
128 (pnc_hi == pn_Cmp_Eq || pnc_hi == pn_Cmp_Ge || pnc_hi == pn_Cmp_Gt)) {
129 /* x >=|>|!= lo || x ==|>=|> hi -> x ==|>=|> hi */
131 } else if (tarval_is_one(tarval_sub(tv_hi, tv_lo, NULL))) { /* lo + 1 == hi */
132 if (pnc_lo == pn_Cmp_Ge && pnc_hi == pn_Cmp_Lt) {
133 /* x >= c || x < c + 1 -> x == c */
134 ir_node *const block = get_nodes_block(cmp_lo);
135 ir_node *const p = new_r_Proj(block, cmp_lo, mode_b, pn_Cmp_Eq);
137 } else if (pnc_lo == pn_Cmp_Gt) {
138 if (pnc_hi == pn_Cmp_Lg) {
139 /* x > c || x != c + 1 -> x > c + 1 */
140 ir_node *const block = get_nodes_block(cmp_hi);
141 ir_node *const p = new_r_Proj(block, cmp_hi, mode_b, pn_Cmp_Gt);
143 } else if (pnc_hi == pn_Cmp_Lt) {
144 /* x > c || x < c + 1 -> false */
145 ir_node *const t = new_Const(tarval_b_false);
147 } else if (pnc_hi == pn_Cmp_Le) {
148 /* x > c || x <= c + 1 -> x != c + 1 */
149 ir_node *const block = get_nodes_block(cmp_hi);
150 ir_node *const p = new_r_Proj(block, cmp_hi, mode_b, pn_Cmp_Eq);
153 } else if (pnc_lo == pn_Cmp_Lg && pnc_hi == pn_Cmp_Lt) {
154 /* x != c || c < c + 1 -> x < c */
155 ir_node *const block = get_nodes_block(cmp_lo);
156 ir_node *const p = new_r_Proj(block, cmp_lo, mode_b, pn_Cmp_Lt);
163 static ir_node *bool_or(cond_pair *const cpair)
165 ir_node *const cmp_lo = cpair->cmp_lo;
166 ir_node *const cmp_hi = cpair->cmp_hi;
167 pn_Cmp const pnc_lo = cpair->pnc_lo;
168 pn_Cmp const pnc_hi = cpair->pnc_hi;
169 ir_node *const proj_lo = cpair->proj_lo;
170 ir_node *const proj_hi = cpair->proj_hi;
171 tarval *const tv_lo = cpair->tv_lo;
172 tarval *const tv_hi = cpair->tv_hi;
174 /* Beware of NaN's, we can only check for (ordered) != here (which is Lg, not Ne) */
175 if ((pnc_lo == pn_Cmp_Ge || pnc_lo == pn_Cmp_Gt || pnc_lo == pn_Cmp_Lg) &&
176 (pnc_hi == pn_Cmp_Lt || pnc_hi == pn_Cmp_Le || pnc_hi == pn_Cmp_Lg)) {
177 /* x >=|>|!= lo | x <|<=|!= hi -> true */
178 ir_node *const t = new_Const(tarval_b_true);
180 } else if ((pnc_lo == pn_Cmp_Lt || pnc_lo == pn_Cmp_Le || pnc_lo == pn_Cmp_Eq) &&
181 (pnc_hi == pn_Cmp_Lt || pnc_hi == pn_Cmp_Le || pnc_hi == pn_Cmp_Lg)) {
182 /* x <|<=|== lo || x <|<=|!= hi -> x <|<=|!= hi */
184 } else if ((pnc_lo == pn_Cmp_Ge || pnc_lo == pn_Cmp_Gt || pnc_lo == pn_Cmp_Lg) &&
185 (pnc_hi == pn_Cmp_Eq || pnc_hi == pn_Cmp_Ge || pnc_hi == pn_Cmp_Gt)) {
186 /* x >=|>|!= lo || x ==|>=|> hi -> x >=|>|!= lo */
188 } else if (tarval_is_one(tarval_sub(tv_hi, tv_lo, NULL))) { /* lo + 1 == hi */
189 if (pnc_lo == pn_Cmp_Lt && pnc_hi == pn_Cmp_Ge) {
190 /* x < c || x >= c + 1 -> x != c */
191 ir_node *const block = get_nodes_block(cmp_lo);
192 ir_node *const p = new_r_Proj(block, cmp_lo, mode_b, pn_Cmp_Lg);
194 } else if (pnc_lo == pn_Cmp_Le) {
195 if (pnc_hi == pn_Cmp_Eq) {
196 /* x <= c || x == c + 1 -> x <= c + 1 */
197 ir_node *const block = get_nodes_block(cmp_hi);
198 ir_node *const p = new_r_Proj(block, cmp_hi, mode_b, pn_Cmp_Le);
200 } else if (pnc_hi == pn_Cmp_Ge) {
201 /* x <= c || x >= c + 1 -> true */
202 ir_node *const t = new_Const(tarval_b_true);
204 } else if (pnc_hi == pn_Cmp_Gt) {
205 /* x <= c || x > c + 1 -> x != c + 1 */
206 ir_node *const block = get_nodes_block(cmp_hi);
207 ir_node *const p = new_r_Proj(block, cmp_hi, mode_b, pn_Cmp_Lg);
210 } else if (pnc_lo == pn_Cmp_Eq && pnc_hi == pn_Cmp_Ge) {
211 /* x == c || x >= c + 1 -> x >= c */
212 ir_node *const block = get_nodes_block(cmp_lo);
213 ir_node *const p = new_r_Proj(block, cmp_lo, mode_b, pn_Cmp_Ge);
220 static void bool_walk(ir_node *n, void *env)
224 if (get_irn_mode(n) != mode_b)
228 ir_node *const l = get_And_left(n);
229 ir_node *const r = get_And_right(n);
230 ir_node * replacement;
232 if (!find_cond_pair(l, r, &cpair))
234 replacement = bool_and(&cpair);
236 exchange(n, replacement);
237 } else if (is_Or(n)) {
238 ir_node *const l = get_Or_left(n);
239 ir_node *const r = get_Or_right(n);
240 ir_node * replacement;
242 if (!find_cond_pair(l, r, &cpair))
244 replacement = bool_or(&cpair);
246 exchange(n, replacement);
251 * Walker, clear Block mark and Phi list
253 static void clear_block_infos(ir_node *node, void *env)
257 /* we visit blocks before any other nodes (from the block) */
261 /* clear the PHI list */
262 set_Block_phis(node, NULL);
263 set_Block_mark(node, 0);
267 * Walker: collect Phi nodes and update the
269 static void collect_phis(ir_node *node, void *env)
274 ir_node *block = get_nodes_block(node);
275 add_Block_phi(block, node);
279 /* Ignore control flow nodes, these will be removed. */
280 if (get_irn_pinned(node) == op_pin_state_pinned &&
281 !is_Block(node) && !is_cfop(node)) {
282 ir_node *block = get_nodes_block(node);
283 set_Block_mark(block, 1);
288 * If node is a Jmp in a block containing no pinned instruction
289 * and having only one predecessor, skip the block and return its
290 * cf predecessor, else the node itself.
292 static ir_node *skip_empty_block(ir_node *node)
299 block = get_nodes_block(node);
300 if(get_Block_n_cfgpreds(block) != 1)
303 if(get_Block_mark(block))
306 return get_Block_cfgpred(block, 0);
309 static void find_cf_and_or_walker(ir_node *block, void *env)
312 int n_cfgpreds = get_Block_n_cfgpreds(block);
318 /* Find the following structure:
330 for(i = 0; i < n_cfgpreds; ++i) {
331 ir_node *lower_block;
334 ir_node *cond_selector;
337 lower_cf = get_Block_cfgpred(block, i);
338 lower_cf = skip_empty_block(lower_cf);
339 if(!is_Proj(lower_cf))
342 cond = get_Proj_pred(lower_cf);
346 lower_block = get_nodes_block(cond);
347 if(get_Block_n_cfgpreds(lower_block) != 1)
350 /* the block must not produce any side-effects */
351 if(get_Block_mark(lower_block))
354 cond_selector = get_Cond_selector(cond);
355 if(get_irn_mode(cond_selector) != mode_b)
358 lower_pred = get_Block_cfgpred_block(lower_block, 0);
360 for(i2 = 0; i2 < n_cfgpreds; ++i2) {
361 ir_node *upper_block;
364 ir_node *upper_cond_selector;
365 ir_node *replacement;
368 upper_cf = get_Block_cfgpred(block, i2);
369 upper_cf = skip_empty_block(upper_cf);
372 upper_block = get_nodes_block(upper_cf);
373 if(upper_block != lower_pred)
376 assert(is_Proj(upper_cf));
377 upper_cond = get_Proj_pred(upper_cf);
378 assert(is_Cond(upper_cond));
379 upper_cond_selector = get_Cond_selector(upper_cond);
380 if(get_irn_mode(upper_cond_selector) != mode_b)
383 /* we have found the structure */
384 /* TODO: check phis */
385 if(!find_cond_pair(cond_selector, upper_cond_selector, &cpair))
388 /* normalize pncs: we need the true case to jump into the
389 * common block (ie. conjunctive normal form) */
390 if(get_Proj_proj(lower_cf) == pn_Cond_false) {
391 if(cpair.proj_lo == cond_selector) {
392 ir_mode *mode = get_tarval_mode(cpair.tv_lo);
393 cpair.pnc_lo = get_negated_pnc(cpair.pnc_lo, mode);
394 cpair.proj_lo = new_r_Proj(lower_block,
395 get_Proj_pred(cpair.proj_lo), mode_b, cpair.pnc_lo);
397 ir_mode *mode = get_tarval_mode(cpair.tv_hi);
398 assert(cpair.proj_hi == cond_selector);
399 cpair.pnc_hi = get_negated_pnc(cpair.pnc_hi, mode);
400 cpair.proj_hi = new_r_Proj(lower_block,
401 get_Proj_pred(cpair.proj_hi), mode_b, cpair.pnc_hi);
404 if(get_Proj_proj(upper_cf) == pn_Cond_false) {
405 if(cpair.proj_lo == upper_cond_selector) {
406 ir_mode *mode = get_tarval_mode(cpair.tv_lo);
407 cpair.pnc_lo = get_negated_pnc(cpair.pnc_lo, mode);
408 cpair.proj_lo = new_r_Proj(upper_block,
409 get_Proj_pred(cpair.proj_lo), mode_b, cpair.pnc_lo);
411 ir_mode *mode = get_tarval_mode(cpair.tv_hi);
412 assert(cpair.proj_hi == upper_cond_selector);
413 cpair.pnc_hi = get_negated_pnc(cpair.pnc_hi, mode);
414 cpair.proj_hi = new_r_Proj(upper_block,
415 get_Proj_pred(cpair.proj_hi), mode_b, cpair.pnc_hi);
419 /* can we optimize the case? */
420 replacement = bool_or(&cpair);
421 if(replacement == NULL)
424 /* move all nodes from lower block to upper block */
425 exchange(lower_block, upper_block);
427 set_Block_cfgpred(block, i2, new_Bad());
429 /* the optimisations expected the true case to jump */
430 if(get_Proj_proj(lower_cf) == pn_Cond_false) {
431 ir_node *block = get_nodes_block(replacement);
432 replacement = new_rd_Not(NULL, block, replacement, mode_b);
434 set_Cond_selector(cond, replacement);
436 ir_fprintf(stderr, "replaced (ub %+F)\n", upper_block);
442 void opt_bool(ir_graph *const irg)
444 irg_walk_graph(irg, NULL, bool_walk, NULL);
446 ir_reserve_resources(irg, IR_RESOURCE_BLOCK_MARK | IR_RESOURCE_PHI_LIST);
448 irg_walk_graph(irg, clear_block_infos, collect_phis, NULL);
450 irg_block_walk_graph(irg, NULL, find_cf_and_or_walker, NULL);
452 set_irg_outs_inconsistent(irg);
453 set_irg_doms_inconsistent(irg);
454 set_irg_extblk_inconsistent(irg);
455 set_irg_loopinfo_inconsistent(irg);
457 ir_free_resources(irg, IR_RESOURCE_BLOCK_MARK | IR_RESOURCE_PHI_LIST);
460 /* Creates an ir_graph pass for opt_bool. */
461 ir_graph_pass_t *opt_bool_pass(const char *name, int verify, int dump)
463 return def_graph_pass(name ? name : "opt_bool", verify, dump, opt_bool);
464 } /* opt_bool_pass */