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531b10fc SB |
1 | /* Lower GIMPLE_SWITCH expressions to something more efficient than |
2 | a jump table. | |
d1e082c2 | 3 | Copyright (C) 2006-2013 Free Software Foundation, Inc. |
b6e99746 MJ |
4 | |
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify it | |
8 | under the terms of the GNU General Public License as published by the | |
9 | Free Software Foundation; either version 3, or (at your option) any | |
10 | later version. | |
11 | ||
12 | GCC is distributed in the hope that it will be useful, but WITHOUT | |
13 | ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
15 | for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GCC; see the file COPYING3. If not, write to the Free | |
19 | Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA | |
20 | 02110-1301, USA. */ | |
21 | ||
531b10fc SB |
22 | /* This file handles the lowering of GIMPLE_SWITCH to an indexed |
23 | load, or a series of bit-test-and-branch expressions. */ | |
24 | ||
25 | #include "config.h" | |
26 | #include "system.h" | |
27 | #include "coretypes.h" | |
28 | #include "tm.h" | |
29 | #include "line-map.h" | |
30 | #include "params.h" | |
31 | #include "flags.h" | |
32 | #include "tree.h" | |
33 | #include "basic-block.h" | |
45b0be94 | 34 | #include "gimplify.h" |
5be5c238 | 35 | #include "gimple-iterator.h" |
442b4905 AM |
36 | #include "gimple-ssa.h" |
37 | #include "cgraph.h" | |
38 | #include "tree-cfg.h" | |
39 | #include "tree-phinodes.h" | |
40 | #include "tree-ssanames.h" | |
531b10fc SB |
41 | #include "tree-pass.h" |
42 | #include "gimple-pretty-print.h" | |
a9e0d843 | 43 | #include "cfgloop.h" |
7ee2468b SB |
44 | |
45 | /* ??? For lang_hooks.types.type_for_mode, but is there a word_mode | |
46 | type in the GIMPLE type system that is language-independent? */ | |
531b10fc SB |
47 | #include "langhooks.h" |
48 | ||
49 | /* Need to include expr.h and optabs.h for lshift_cheap_p. */ | |
50 | #include "expr.h" | |
51 | #include "optabs.h" | |
52 | \f | |
53 | /* Maximum number of case bit tests. | |
54 | FIXME: This should be derived from PARAM_CASE_VALUES_THRESHOLD and | |
55 | targetm.case_values_threshold(), or be its own param. */ | |
56 | #define MAX_CASE_BIT_TESTS 3 | |
57 | ||
58 | /* Split the basic block at the statement pointed to by GSIP, and insert | |
59 | a branch to the target basic block of E_TRUE conditional on tree | |
60 | expression COND. | |
61 | ||
62 | It is assumed that there is already an edge from the to-be-split | |
63 | basic block to E_TRUE->dest block. This edge is removed, and the | |
64 | profile information on the edge is re-used for the new conditional | |
65 | jump. | |
66 | ||
67 | The CFG is updated. The dominator tree will not be valid after | |
68 | this transformation, but the immediate dominators are updated if | |
69 | UPDATE_DOMINATORS is true. | |
70 | ||
71 | Returns the newly created basic block. */ | |
72 | ||
73 | static basic_block | |
74 | hoist_edge_and_branch_if_true (gimple_stmt_iterator *gsip, | |
75 | tree cond, edge e_true, | |
76 | bool update_dominators) | |
77 | { | |
78 | tree tmp; | |
79 | gimple cond_stmt; | |
80 | edge e_false; | |
81 | basic_block new_bb, split_bb = gsi_bb (*gsip); | |
82 | bool dominated_e_true = false; | |
83 | ||
84 | gcc_assert (e_true->src == split_bb); | |
85 | ||
86 | if (update_dominators | |
87 | && get_immediate_dominator (CDI_DOMINATORS, e_true->dest) == split_bb) | |
88 | dominated_e_true = true; | |
89 | ||
90 | tmp = force_gimple_operand_gsi (gsip, cond, /*simple=*/true, NULL, | |
91 | /*before=*/true, GSI_SAME_STMT); | |
92 | cond_stmt = gimple_build_cond_from_tree (tmp, NULL_TREE, NULL_TREE); | |
93 | gsi_insert_before (gsip, cond_stmt, GSI_SAME_STMT); | |
94 | ||
95 | e_false = split_block (split_bb, cond_stmt); | |
96 | new_bb = e_false->dest; | |
97 | redirect_edge_pred (e_true, split_bb); | |
98 | ||
99 | e_true->flags &= ~EDGE_FALLTHRU; | |
100 | e_true->flags |= EDGE_TRUE_VALUE; | |
101 | ||
102 | e_false->flags &= ~EDGE_FALLTHRU; | |
103 | e_false->flags |= EDGE_FALSE_VALUE; | |
104 | e_false->probability = REG_BR_PROB_BASE - e_true->probability; | |
105 | e_false->count = split_bb->count - e_true->count; | |
106 | new_bb->count = e_false->count; | |
107 | ||
108 | if (update_dominators) | |
109 | { | |
110 | if (dominated_e_true) | |
111 | set_immediate_dominator (CDI_DOMINATORS, e_true->dest, split_bb); | |
112 | set_immediate_dominator (CDI_DOMINATORS, e_false->dest, split_bb); | |
113 | } | |
114 | ||
115 | return new_bb; | |
116 | } | |
117 | ||
118 | ||
119 | /* Determine whether "1 << x" is relatively cheap in word_mode. */ | |
120 | /* FIXME: This is the function that we need rtl.h and optabs.h for. | |
121 | This function (and similar RTL-related cost code in e.g. IVOPTS) should | |
122 | be moved to some kind of interface file for GIMPLE/RTL interactions. */ | |
123 | static bool | |
124 | lshift_cheap_p (void) | |
125 | { | |
126 | /* FIXME: This should be made target dependent via this "this_target" | |
127 | mechanism, similar to e.g. can_copy_init_p in gcse.c. */ | |
128 | static bool init[2] = {false, false}; | |
129 | static bool cheap[2] = {true, true}; | |
130 | bool speed_p; | |
131 | ||
132 | /* If the targer has no lshift in word_mode, the operation will most | |
133 | probably not be cheap. ??? Does GCC even work for such targets? */ | |
134 | if (optab_handler (ashl_optab, word_mode) == CODE_FOR_nothing) | |
135 | return false; | |
136 | ||
137 | speed_p = optimize_insn_for_speed_p (); | |
138 | ||
139 | if (!init[speed_p]) | |
140 | { | |
141 | rtx reg = gen_raw_REG (word_mode, 10000); | |
142 | int cost = set_src_cost (gen_rtx_ASHIFT (word_mode, const1_rtx, reg), | |
143 | speed_p); | |
144 | cheap[speed_p] = cost < COSTS_N_INSNS (MAX_CASE_BIT_TESTS); | |
145 | init[speed_p] = true; | |
146 | } | |
147 | ||
148 | return cheap[speed_p]; | |
149 | } | |
150 | ||
151 | /* Return true if a switch should be expanded as a bit test. | |
152 | RANGE is the difference between highest and lowest case. | |
153 | UNIQ is number of unique case node targets, not counting the default case. | |
154 | COUNT is the number of comparisons needed, not counting the default case. */ | |
155 | ||
156 | static bool | |
157 | expand_switch_using_bit_tests_p (tree range, | |
158 | unsigned int uniq, | |
159 | unsigned int count) | |
160 | { | |
161 | return (((uniq == 1 && count >= 3) | |
162 | || (uniq == 2 && count >= 5) | |
163 | || (uniq == 3 && count >= 6)) | |
164 | && lshift_cheap_p () | |
165 | && compare_tree_int (range, GET_MODE_BITSIZE (word_mode)) < 0 | |
166 | && compare_tree_int (range, 0) > 0); | |
167 | } | |
168 | \f | |
169 | /* Implement switch statements with bit tests | |
170 | ||
171 | A GIMPLE switch statement can be expanded to a short sequence of bit-wise | |
172 | comparisons. "switch(x)" is converted into "if ((1 << (x-MINVAL)) & CST)" | |
173 | where CST and MINVAL are integer constants. This is better than a series | |
174 | of compare-and-banch insns in some cases, e.g. we can implement: | |
175 | ||
176 | if ((x==4) || (x==6) || (x==9) || (x==11)) | |
177 | ||
178 | as a single bit test: | |
179 | ||
180 | if ((1<<x) & ((1<<4)|(1<<6)|(1<<9)|(1<<11))) | |
181 | ||
182 | This transformation is only applied if the number of case targets is small, | |
34540577 | 183 | if CST constains at least 3 bits, and "1 << x" is cheap. The bit tests are |
531b10fc SB |
184 | performed in "word_mode". |
185 | ||
186 | The following example shows the code the transformation generates: | |
187 | ||
188 | int bar(int x) | |
189 | { | |
190 | switch (x) | |
191 | { | |
192 | case '0': case '1': case '2': case '3': case '4': | |
193 | case '5': case '6': case '7': case '8': case '9': | |
194 | case 'A': case 'B': case 'C': case 'D': case 'E': | |
195 | case 'F': | |
196 | return 1; | |
197 | } | |
198 | return 0; | |
199 | } | |
200 | ||
201 | ==> | |
202 | ||
203 | bar (int x) | |
204 | { | |
205 | tmp1 = x - 48; | |
206 | if (tmp1 > (70 - 48)) goto L2; | |
207 | tmp2 = 1 << tmp1; | |
208 | tmp3 = 0b11111100000001111111111; | |
209 | if ((tmp2 & tmp3) != 0) goto L1 ; else goto L2; | |
210 | L1: | |
211 | return 1; | |
212 | L2: | |
213 | return 0; | |
214 | } | |
215 | ||
216 | TODO: There are still some improvements to this transformation that could | |
217 | be implemented: | |
218 | ||
219 | * A narrower mode than word_mode could be used if that is cheaper, e.g. | |
220 | for x86_64 where a narrower-mode shift may result in smaller code. | |
221 | ||
222 | * The compounded constant could be shifted rather than the one. The | |
223 | test would be either on the sign bit or on the least significant bit, | |
224 | depending on the direction of the shift. On some machines, the test | |
225 | for the branch would be free if the bit to test is already set by the | |
226 | shift operation. | |
227 | ||
228 | This transformation was contributed by Roger Sayle, see this e-mail: | |
229 | http://gcc.gnu.org/ml/gcc-patches/2003-01/msg01950.html | |
230 | */ | |
231 | ||
232 | /* A case_bit_test represents a set of case nodes that may be | |
233 | selected from using a bit-wise comparison. HI and LO hold | |
234 | the integer to be tested against, TARGET_EDGE contains the | |
235 | edge to the basic block to jump to upon success and BITS | |
236 | counts the number of case nodes handled by this test, | |
237 | typically the number of bits set in HI:LO. The LABEL field | |
238 | is used to quickly identify all cases in this set without | |
239 | looking at label_to_block for every case label. */ | |
240 | ||
241 | struct case_bit_test | |
242 | { | |
243 | HOST_WIDE_INT hi; | |
244 | HOST_WIDE_INT lo; | |
245 | edge target_edge; | |
246 | tree label; | |
247 | int bits; | |
248 | }; | |
249 | ||
250 | /* Comparison function for qsort to order bit tests by decreasing | |
251 | probability of execution. Our best guess comes from a measured | |
252 | profile. If the profile counts are equal, break even on the | |
253 | number of case nodes, i.e. the node with the most cases gets | |
254 | tested first. | |
255 | ||
256 | TODO: Actually this currently runs before a profile is available. | |
257 | Therefore the case-as-bit-tests transformation should be done | |
258 | later in the pass pipeline, or something along the lines of | |
259 | "Efficient and effective branch reordering using profile data" | |
260 | (Yang et. al., 2002) should be implemented (although, how good | |
261 | is a paper is called "Efficient and effective ..." when the | |
262 | latter is implied by the former, but oh well...). */ | |
263 | ||
264 | static int | |
265 | case_bit_test_cmp (const void *p1, const void *p2) | |
266 | { | |
267 | const struct case_bit_test *const d1 = (const struct case_bit_test *) p1; | |
268 | const struct case_bit_test *const d2 = (const struct case_bit_test *) p2; | |
269 | ||
270 | if (d2->target_edge->count != d1->target_edge->count) | |
271 | return d2->target_edge->count - d1->target_edge->count; | |
272 | if (d2->bits != d1->bits) | |
273 | return d2->bits - d1->bits; | |
274 | ||
275 | /* Stabilize the sort. */ | |
276 | return LABEL_DECL_UID (d2->label) - LABEL_DECL_UID (d1->label); | |
277 | } | |
278 | ||
279 | /* Expand a switch statement by a short sequence of bit-wise | |
280 | comparisons. "switch(x)" is effectively converted into | |
281 | "if ((1 << (x-MINVAL)) & CST)" where CST and MINVAL are | |
282 | integer constants. | |
283 | ||
284 | INDEX_EXPR is the value being switched on. | |
285 | ||
286 | MINVAL is the lowest case value of in the case nodes, | |
287 | and RANGE is highest value minus MINVAL. MINVAL and RANGE | |
288 | are not guaranteed to be of the same type as INDEX_EXPR | |
289 | (the gimplifier doesn't change the type of case label values, | |
290 | and MINVAL and RANGE are derived from those values). | |
291 | ||
292 | There *MUST* be MAX_CASE_BIT_TESTS or less unique case | |
293 | node targets. */ | |
294 | ||
295 | static void | |
296 | emit_case_bit_tests (gimple swtch, tree index_expr, | |
297 | tree minval, tree range) | |
298 | { | |
299 | struct case_bit_test test[MAX_CASE_BIT_TESTS]; | |
300 | unsigned int i, j, k; | |
301 | unsigned int count; | |
302 | ||
303 | basic_block switch_bb = gimple_bb (swtch); | |
304 | basic_block default_bb, new_default_bb, new_bb; | |
305 | edge default_edge; | |
306 | bool update_dom = dom_info_available_p (CDI_DOMINATORS); | |
307 | ||
6e1aa848 | 308 | vec<basic_block> bbs_to_fix_dom = vNULL; |
531b10fc SB |
309 | |
310 | tree index_type = TREE_TYPE (index_expr); | |
311 | tree unsigned_index_type = unsigned_type_for (index_type); | |
312 | unsigned int branch_num = gimple_switch_num_labels (swtch); | |
313 | ||
314 | gimple_stmt_iterator gsi; | |
315 | gimple shift_stmt; | |
316 | ||
317 | tree idx, tmp, csui; | |
318 | tree word_type_node = lang_hooks.types.type_for_mode (word_mode, 1); | |
319 | tree word_mode_zero = fold_convert (word_type_node, integer_zero_node); | |
320 | tree word_mode_one = fold_convert (word_type_node, integer_one_node); | |
321 | ||
322 | memset (&test, 0, sizeof (test)); | |
323 | ||
324 | /* Get the edge for the default case. */ | |
fd8d363e | 325 | tmp = gimple_switch_default_label (swtch); |
531b10fc SB |
326 | default_bb = label_to_block (CASE_LABEL (tmp)); |
327 | default_edge = find_edge (switch_bb, default_bb); | |
328 | ||
329 | /* Go through all case labels, and collect the case labels, profile | |
330 | counts, and other information we need to build the branch tests. */ | |
331 | count = 0; | |
332 | for (i = 1; i < branch_num; i++) | |
333 | { | |
334 | unsigned int lo, hi; | |
335 | tree cs = gimple_switch_label (swtch, i); | |
336 | tree label = CASE_LABEL (cs); | |
8166ff4d | 337 | edge e = find_edge (switch_bb, label_to_block (label)); |
531b10fc | 338 | for (k = 0; k < count; k++) |
8166ff4d | 339 | if (e == test[k].target_edge) |
531b10fc SB |
340 | break; |
341 | ||
342 | if (k == count) | |
343 | { | |
531b10fc SB |
344 | gcc_checking_assert (count < MAX_CASE_BIT_TESTS); |
345 | test[k].hi = 0; | |
346 | test[k].lo = 0; | |
347 | test[k].target_edge = e; | |
348 | test[k].label = label; | |
349 | test[k].bits = 1; | |
350 | count++; | |
351 | } | |
352 | else | |
353 | test[k].bits++; | |
354 | ||
355 | lo = tree_low_cst (int_const_binop (MINUS_EXPR, | |
356 | CASE_LOW (cs), minval), | |
357 | 1); | |
358 | if (CASE_HIGH (cs) == NULL_TREE) | |
359 | hi = lo; | |
360 | else | |
361 | hi = tree_low_cst (int_const_binop (MINUS_EXPR, | |
362 | CASE_HIGH (cs), minval), | |
363 | 1); | |
364 | ||
365 | for (j = lo; j <= hi; j++) | |
366 | if (j >= HOST_BITS_PER_WIDE_INT) | |
367 | test[k].hi |= (HOST_WIDE_INT) 1 << (j - HOST_BITS_PER_INT); | |
368 | else | |
369 | test[k].lo |= (HOST_WIDE_INT) 1 << j; | |
370 | } | |
371 | ||
c3284718 | 372 | qsort (test, count, sizeof (*test), case_bit_test_cmp); |
531b10fc SB |
373 | |
374 | /* We generate two jumps to the default case label. | |
375 | Split the default edge, so that we don't have to do any PHI node | |
376 | updating. */ | |
377 | new_default_bb = split_edge (default_edge); | |
378 | ||
379 | if (update_dom) | |
380 | { | |
9771b263 DN |
381 | bbs_to_fix_dom.create (10); |
382 | bbs_to_fix_dom.quick_push (switch_bb); | |
383 | bbs_to_fix_dom.quick_push (default_bb); | |
384 | bbs_to_fix_dom.quick_push (new_default_bb); | |
531b10fc SB |
385 | } |
386 | ||
387 | /* Now build the test-and-branch code. */ | |
388 | ||
389 | gsi = gsi_last_bb (switch_bb); | |
390 | ||
d9e408de TV |
391 | /* idx = (unsigned)x - minval. */ |
392 | idx = fold_convert (unsigned_index_type, index_expr); | |
393 | idx = fold_build2 (MINUS_EXPR, unsigned_index_type, idx, | |
394 | fold_convert (unsigned_index_type, minval)); | |
531b10fc SB |
395 | idx = force_gimple_operand_gsi (&gsi, idx, |
396 | /*simple=*/true, NULL_TREE, | |
397 | /*before=*/true, GSI_SAME_STMT); | |
398 | ||
399 | /* if (idx > range) goto default */ | |
400 | range = force_gimple_operand_gsi (&gsi, | |
401 | fold_convert (unsigned_index_type, range), | |
402 | /*simple=*/true, NULL_TREE, | |
403 | /*before=*/true, GSI_SAME_STMT); | |
404 | tmp = fold_build2 (GT_EXPR, boolean_type_node, idx, range); | |
405 | new_bb = hoist_edge_and_branch_if_true (&gsi, tmp, default_edge, update_dom); | |
406 | if (update_dom) | |
9771b263 | 407 | bbs_to_fix_dom.quick_push (new_bb); |
531b10fc SB |
408 | gcc_assert (gimple_bb (swtch) == new_bb); |
409 | gsi = gsi_last_bb (new_bb); | |
410 | ||
411 | /* Any blocks dominated by the GIMPLE_SWITCH, but that are not successors | |
412 | of NEW_BB, are still immediately dominated by SWITCH_BB. Make it so. */ | |
413 | if (update_dom) | |
414 | { | |
9771b263 | 415 | vec<basic_block> dom_bbs; |
531b10fc SB |
416 | basic_block dom_son; |
417 | ||
418 | dom_bbs = get_dominated_by (CDI_DOMINATORS, new_bb); | |
9771b263 | 419 | FOR_EACH_VEC_ELT (dom_bbs, i, dom_son) |
531b10fc SB |
420 | { |
421 | edge e = find_edge (new_bb, dom_son); | |
422 | if (e && single_pred_p (e->dest)) | |
423 | continue; | |
424 | set_immediate_dominator (CDI_DOMINATORS, dom_son, switch_bb); | |
9771b263 | 425 | bbs_to_fix_dom.safe_push (dom_son); |
531b10fc | 426 | } |
9771b263 | 427 | dom_bbs.release (); |
531b10fc SB |
428 | } |
429 | ||
430 | /* csui = (1 << (word_mode) idx) */ | |
83d5977e | 431 | csui = make_ssa_name (word_type_node, NULL); |
531b10fc SB |
432 | tmp = fold_build2 (LSHIFT_EXPR, word_type_node, word_mode_one, |
433 | fold_convert (word_type_node, idx)); | |
434 | tmp = force_gimple_operand_gsi (&gsi, tmp, | |
435 | /*simple=*/false, NULL_TREE, | |
436 | /*before=*/true, GSI_SAME_STMT); | |
437 | shift_stmt = gimple_build_assign (csui, tmp); | |
531b10fc SB |
438 | gsi_insert_before (&gsi, shift_stmt, GSI_SAME_STMT); |
439 | update_stmt (shift_stmt); | |
440 | ||
441 | /* for each unique set of cases: | |
442 | if (const & csui) goto target */ | |
443 | for (k = 0; k < count; k++) | |
444 | { | |
445 | tmp = build_int_cst_wide (word_type_node, test[k].lo, test[k].hi); | |
446 | tmp = fold_build2 (BIT_AND_EXPR, word_type_node, csui, tmp); | |
447 | tmp = force_gimple_operand_gsi (&gsi, tmp, | |
448 | /*simple=*/true, NULL_TREE, | |
449 | /*before=*/true, GSI_SAME_STMT); | |
450 | tmp = fold_build2 (NE_EXPR, boolean_type_node, tmp, word_mode_zero); | |
451 | new_bb = hoist_edge_and_branch_if_true (&gsi, tmp, test[k].target_edge, | |
452 | update_dom); | |
453 | if (update_dom) | |
9771b263 | 454 | bbs_to_fix_dom.safe_push (new_bb); |
531b10fc SB |
455 | gcc_assert (gimple_bb (swtch) == new_bb); |
456 | gsi = gsi_last_bb (new_bb); | |
457 | } | |
458 | ||
459 | /* We should have removed all edges now. */ | |
460 | gcc_assert (EDGE_COUNT (gsi_bb (gsi)->succs) == 0); | |
461 | ||
462 | /* If nothing matched, go to the default label. */ | |
463 | make_edge (gsi_bb (gsi), new_default_bb, EDGE_FALLTHRU); | |
464 | ||
465 | /* The GIMPLE_SWITCH is now redundant. */ | |
466 | gsi_remove (&gsi, true); | |
467 | ||
468 | if (update_dom) | |
469 | { | |
470 | /* Fix up the dominator tree. */ | |
471 | iterate_fix_dominators (CDI_DOMINATORS, bbs_to_fix_dom, true); | |
9771b263 | 472 | bbs_to_fix_dom.release (); |
531b10fc SB |
473 | } |
474 | } | |
475 | \f | |
b6e99746 MJ |
476 | /* |
477 | Switch initialization conversion | |
478 | ||
479 | The following pass changes simple initializations of scalars in a switch | |
fade902a SB |
480 | statement into initializations from a static array. Obviously, the values |
481 | must be constant and known at compile time and a default branch must be | |
b6e99746 MJ |
482 | provided. For example, the following code: |
483 | ||
484 | int a,b; | |
485 | ||
486 | switch (argc) | |
487 | { | |
488 | case 1: | |
489 | case 2: | |
490 | a_1 = 8; | |
491 | b_1 = 6; | |
492 | break; | |
493 | case 3: | |
494 | a_2 = 9; | |
495 | b_2 = 5; | |
496 | break; | |
497 | case 12: | |
498 | a_3 = 10; | |
499 | b_3 = 4; | |
500 | break; | |
501 | default: | |
502 | a_4 = 16; | |
503 | b_4 = 1; | |
886cd84f | 504 | break; |
b6e99746 MJ |
505 | } |
506 | a_5 = PHI <a_1, a_2, a_3, a_4> | |
507 | b_5 = PHI <b_1, b_2, b_3, b_4> | |
508 | ||
509 | ||
510 | is changed into: | |
511 | ||
512 | static const int = CSWTCH01[] = {6, 6, 5, 1, 1, 1, 1, 1, 1, 1, 1, 4}; | |
513 | static const int = CSWTCH02[] = {8, 8, 9, 16, 16, 16, 16, 16, 16, 16, | |
514 | 16, 16, 10}; | |
515 | ||
516 | if (((unsigned) argc) - 1 < 11) | |
517 | { | |
518 | a_6 = CSWTCH02[argc - 1]; | |
519 | b_6 = CSWTCH01[argc - 1]; | |
520 | } | |
521 | else | |
522 | { | |
523 | a_7 = 16; | |
524 | b_7 = 1; | |
525 | } | |
886cd84f SB |
526 | a_5 = PHI <a_6, a_7> |
527 | b_b = PHI <b_6, b_7> | |
b6e99746 MJ |
528 | |
529 | There are further constraints. Specifically, the range of values across all | |
530 | case labels must not be bigger than SWITCH_CONVERSION_BRANCH_RATIO (default | |
531b10fc | 531 | eight) times the number of the actual switch branches. |
b6e99746 | 532 | |
531b10fc SB |
533 | This transformation was contributed by Martin Jambor, see this e-mail: |
534 | http://gcc.gnu.org/ml/gcc-patches/2008-07/msg00011.html */ | |
b6e99746 MJ |
535 | |
536 | /* The main structure of the pass. */ | |
537 | struct switch_conv_info | |
538 | { | |
886cd84f | 539 | /* The expression used to decide the switch branch. */ |
b6e99746 MJ |
540 | tree index_expr; |
541 | ||
886cd84f SB |
542 | /* The following integer constants store the minimum and maximum value |
543 | covered by the case labels. */ | |
b6e99746 | 544 | tree range_min; |
886cd84f | 545 | tree range_max; |
b6e99746 | 546 | |
886cd84f SB |
547 | /* The difference between the above two numbers. Stored here because it |
548 | is used in all the conversion heuristics, as well as for some of the | |
549 | transformation, and it is expensive to re-compute it all the time. */ | |
b6e99746 MJ |
550 | tree range_size; |
551 | ||
886cd84f | 552 | /* Basic block that contains the actual GIMPLE_SWITCH. */ |
b6e99746 MJ |
553 | basic_block switch_bb; |
554 | ||
886cd84f SB |
555 | /* Basic block that is the target of the default case. */ |
556 | basic_block default_bb; | |
557 | ||
558 | /* The single successor block of all branches out of the GIMPLE_SWITCH, | |
559 | if such a block exists. Otherwise NULL. */ | |
b6e99746 MJ |
560 | basic_block final_bb; |
561 | ||
886cd84f SB |
562 | /* The probability of the default edge in the replaced switch. */ |
563 | int default_prob; | |
564 | ||
565 | /* The count of the default edge in the replaced switch. */ | |
566 | gcov_type default_count; | |
567 | ||
568 | /* Combined count of all other (non-default) edges in the replaced switch. */ | |
569 | gcov_type other_count; | |
570 | ||
b6e99746 MJ |
571 | /* Number of phi nodes in the final bb (that we'll be replacing). */ |
572 | int phi_count; | |
573 | ||
b1ae1681 | 574 | /* Array of default values, in the same order as phi nodes. */ |
b6e99746 MJ |
575 | tree *default_values; |
576 | ||
577 | /* Constructors of new static arrays. */ | |
9771b263 | 578 | vec<constructor_elt, va_gc> **constructors; |
b6e99746 MJ |
579 | |
580 | /* Array of ssa names that are initialized with a value from a new static | |
581 | array. */ | |
582 | tree *target_inbound_names; | |
583 | ||
584 | /* Array of ssa names that are initialized with the default value if the | |
585 | switch expression is out of range. */ | |
586 | tree *target_outbound_names; | |
587 | ||
b1ae1681 MJ |
588 | /* The first load statement that loads a temporary from a new static array. |
589 | */ | |
726a989a | 590 | gimple arr_ref_first; |
b6e99746 MJ |
591 | |
592 | /* The last load statement that loads a temporary from a new static array. */ | |
726a989a | 593 | gimple arr_ref_last; |
b6e99746 MJ |
594 | |
595 | /* String reason why the case wasn't a good candidate that is written to the | |
596 | dump file, if there is one. */ | |
597 | const char *reason; | |
8e97bc2b JJ |
598 | |
599 | /* Parameters for expand_switch_using_bit_tests. Should be computed | |
600 | the same way as in expand_case. */ | |
886cd84f SB |
601 | unsigned int uniq; |
602 | unsigned int count; | |
b6e99746 MJ |
603 | }; |
604 | ||
886cd84f | 605 | /* Collect information about GIMPLE_SWITCH statement SWTCH into INFO. */ |
b6e99746 | 606 | |
886cd84f SB |
607 | static void |
608 | collect_switch_conv_info (gimple swtch, struct switch_conv_info *info) | |
b6e99746 | 609 | { |
726a989a | 610 | unsigned int branch_num = gimple_switch_num_labels (swtch); |
886cd84f SB |
611 | tree min_case, max_case; |
612 | unsigned int count, i; | |
613 | edge e, e_default; | |
614 | edge_iterator ei; | |
615 | ||
616 | memset (info, 0, sizeof (*info)); | |
b6e99746 MJ |
617 | |
618 | /* The gimplifier has already sorted the cases by CASE_LOW and ensured there | |
fd8d363e SB |
619 | is a default label which is the first in the vector. |
620 | Collect the bits we can deduce from the CFG. */ | |
886cd84f SB |
621 | info->index_expr = gimple_switch_index (swtch); |
622 | info->switch_bb = gimple_bb (swtch); | |
623 | info->default_bb = | |
fd8d363e | 624 | label_to_block (CASE_LABEL (gimple_switch_default_label (swtch))); |
886cd84f SB |
625 | e_default = find_edge (info->switch_bb, info->default_bb); |
626 | info->default_prob = e_default->probability; | |
627 | info->default_count = e_default->count; | |
628 | FOR_EACH_EDGE (e, ei, info->switch_bb->succs) | |
629 | if (e != e_default) | |
630 | info->other_count += e->count; | |
b6e99746 | 631 | |
886cd84f SB |
632 | /* See if there is one common successor block for all branch |
633 | targets. If it exists, record it in FINAL_BB. */ | |
634 | FOR_EACH_EDGE (e, ei, info->switch_bb->succs) | |
635 | { | |
636 | if (! single_pred_p (e->dest)) | |
637 | { | |
638 | info->final_bb = e->dest; | |
639 | break; | |
640 | } | |
641 | } | |
642 | if (info->final_bb) | |
643 | FOR_EACH_EDGE (e, ei, info->switch_bb->succs) | |
644 | { | |
645 | if (e->dest == info->final_bb) | |
646 | continue; | |
647 | ||
648 | if (single_pred_p (e->dest) | |
649 | && single_succ_p (e->dest) | |
650 | && single_succ (e->dest) == info->final_bb) | |
651 | continue; | |
652 | ||
653 | info->final_bb = NULL; | |
654 | break; | |
655 | } | |
656 | ||
657 | /* Get upper and lower bounds of case values, and the covered range. */ | |
658 | min_case = gimple_switch_label (swtch, 1); | |
726a989a | 659 | max_case = gimple_switch_label (swtch, branch_num - 1); |
886cd84f SB |
660 | |
661 | info->range_min = CASE_LOW (min_case); | |
b6e99746 | 662 | if (CASE_HIGH (max_case) != NULL_TREE) |
886cd84f | 663 | info->range_max = CASE_HIGH (max_case); |
b6e99746 | 664 | else |
886cd84f SB |
665 | info->range_max = CASE_LOW (max_case); |
666 | ||
667 | info->range_size = | |
668 | int_const_binop (MINUS_EXPR, info->range_max, info->range_min); | |
b6e99746 | 669 | |
886cd84f SB |
670 | /* Get a count of the number of case labels. Single-valued case labels |
671 | simply count as one, but a case range counts double, since it may | |
672 | require two compares if it gets lowered as a branching tree. */ | |
673 | count = 0; | |
674 | for (i = 1; i < branch_num; i++) | |
675 | { | |
676 | tree elt = gimple_switch_label (swtch, i); | |
677 | count++; | |
678 | if (CASE_HIGH (elt) | |
679 | && ! tree_int_cst_equal (CASE_LOW (elt), CASE_HIGH (elt))) | |
680 | count++; | |
681 | } | |
682 | info->count = count; | |
683 | ||
684 | /* Get the number of unique non-default targets out of the GIMPLE_SWITCH | |
685 | block. Assume a CFG cleanup would have already removed degenerate | |
686 | switch statements, this allows us to just use EDGE_COUNT. */ | |
687 | info->uniq = EDGE_COUNT (gimple_bb (swtch)->succs) - 1; | |
688 | } | |
b6e99746 | 689 | |
886cd84f SB |
690 | /* Checks whether the range given by individual case statements of the SWTCH |
691 | switch statement isn't too big and whether the number of branches actually | |
692 | satisfies the size of the new array. */ | |
b6e99746 | 693 | |
886cd84f SB |
694 | static bool |
695 | check_range (struct switch_conv_info *info) | |
696 | { | |
fade902a SB |
697 | gcc_assert (info->range_size); |
698 | if (!host_integerp (info->range_size, 1)) | |
b6e99746 | 699 | { |
fade902a | 700 | info->reason = "index range way too large or otherwise unusable"; |
b6e99746 MJ |
701 | return false; |
702 | } | |
703 | ||
fade902a | 704 | if ((unsigned HOST_WIDE_INT) tree_low_cst (info->range_size, 1) |
886cd84f | 705 | > ((unsigned) info->count * SWITCH_CONVERSION_BRANCH_RATIO)) |
b6e99746 | 706 | { |
fade902a | 707 | info->reason = "the maximum range-branch ratio exceeded"; |
b6e99746 MJ |
708 | return false; |
709 | } | |
710 | ||
711 | return true; | |
712 | } | |
713 | ||
886cd84f | 714 | /* Checks whether all but the FINAL_BB basic blocks are empty. */ |
b6e99746 MJ |
715 | |
716 | static bool | |
886cd84f | 717 | check_all_empty_except_final (struct switch_conv_info *info) |
b6e99746 | 718 | { |
b6e99746 | 719 | edge e; |
886cd84f | 720 | edge_iterator ei; |
b6e99746 | 721 | |
886cd84f | 722 | FOR_EACH_EDGE (e, ei, info->switch_bb->succs) |
b6e99746 | 723 | { |
886cd84f SB |
724 | if (e->dest == info->final_bb) |
725 | continue; | |
b6e99746 | 726 | |
886cd84f | 727 | if (!empty_block_p (e->dest)) |
b6e99746 | 728 | { |
fade902a | 729 | info->reason = "bad case - a non-final BB not empty"; |
b6e99746 MJ |
730 | return false; |
731 | } | |
b6e99746 MJ |
732 | } |
733 | ||
734 | return true; | |
735 | } | |
736 | ||
737 | /* This function checks whether all required values in phi nodes in final_bb | |
738 | are constants. Required values are those that correspond to a basic block | |
739 | which is a part of the examined switch statement. It returns true if the | |
740 | phi nodes are OK, otherwise false. */ | |
741 | ||
742 | static bool | |
fade902a | 743 | check_final_bb (struct switch_conv_info *info) |
b6e99746 | 744 | { |
726a989a | 745 | gimple_stmt_iterator gsi; |
b6e99746 | 746 | |
fade902a SB |
747 | info->phi_count = 0; |
748 | for (gsi = gsi_start_phis (info->final_bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
b6e99746 | 749 | { |
726a989a RB |
750 | gimple phi = gsi_stmt (gsi); |
751 | unsigned int i; | |
b6e99746 | 752 | |
fade902a | 753 | info->phi_count++; |
b6e99746 | 754 | |
726a989a | 755 | for (i = 0; i < gimple_phi_num_args (phi); i++) |
b6e99746 | 756 | { |
726a989a | 757 | basic_block bb = gimple_phi_arg_edge (phi, i)->src; |
b6e99746 | 758 | |
fade902a SB |
759 | if (bb == info->switch_bb |
760 | || (single_pred_p (bb) && single_pred (bb) == info->switch_bb)) | |
b6e99746 | 761 | { |
f6e6e990 JJ |
762 | tree reloc, val; |
763 | ||
764 | val = gimple_phi_arg_def (phi, i); | |
765 | if (!is_gimple_ip_invariant (val)) | |
766 | { | |
fade902a | 767 | info->reason = "non-invariant value from a case"; |
f6e6e990 JJ |
768 | return false; /* Non-invariant argument. */ |
769 | } | |
770 | reloc = initializer_constant_valid_p (val, TREE_TYPE (val)); | |
771 | if ((flag_pic && reloc != null_pointer_node) | |
772 | || (!flag_pic && reloc == NULL_TREE)) | |
773 | { | |
774 | if (reloc) | |
fade902a SB |
775 | info->reason |
776 | = "value from a case would need runtime relocations"; | |
f6e6e990 | 777 | else |
fade902a SB |
778 | info->reason |
779 | = "value from a case is not a valid initializer"; | |
f6e6e990 JJ |
780 | return false; |
781 | } | |
b6e99746 MJ |
782 | } |
783 | } | |
784 | } | |
785 | ||
786 | return true; | |
787 | } | |
788 | ||
789 | /* The following function allocates default_values, target_{in,out}_names and | |
790 | constructors arrays. The last one is also populated with pointers to | |
791 | vectors that will become constructors of new arrays. */ | |
792 | ||
793 | static void | |
fade902a | 794 | create_temp_arrays (struct switch_conv_info *info) |
b6e99746 MJ |
795 | { |
796 | int i; | |
797 | ||
fade902a | 798 | info->default_values = XCNEWVEC (tree, info->phi_count * 3); |
9771b263 DN |
799 | /* ??? Macros do not support multi argument templates in their |
800 | argument list. We create a typedef to work around that problem. */ | |
801 | typedef vec<constructor_elt, va_gc> *vec_constructor_elt_gc; | |
802 | info->constructors = XCNEWVEC (vec_constructor_elt_gc, info->phi_count); | |
fade902a SB |
803 | info->target_inbound_names = info->default_values + info->phi_count; |
804 | info->target_outbound_names = info->target_inbound_names + info->phi_count; | |
805 | for (i = 0; i < info->phi_count; i++) | |
9771b263 | 806 | vec_alloc (info->constructors[i], tree_low_cst (info->range_size, 1) + 1); |
b6e99746 MJ |
807 | } |
808 | ||
809 | /* Free the arrays created by create_temp_arrays(). The vectors that are | |
810 | created by that function are not freed here, however, because they have | |
811 | already become constructors and must be preserved. */ | |
812 | ||
813 | static void | |
fade902a | 814 | free_temp_arrays (struct switch_conv_info *info) |
b6e99746 | 815 | { |
fade902a SB |
816 | XDELETEVEC (info->constructors); |
817 | XDELETEVEC (info->default_values); | |
b6e99746 MJ |
818 | } |
819 | ||
820 | /* Populate the array of default values in the order of phi nodes. | |
821 | DEFAULT_CASE is the CASE_LABEL_EXPR for the default switch branch. */ | |
822 | ||
823 | static void | |
fade902a | 824 | gather_default_values (tree default_case, struct switch_conv_info *info) |
b6e99746 | 825 | { |
726a989a | 826 | gimple_stmt_iterator gsi; |
b6e99746 MJ |
827 | basic_block bb = label_to_block (CASE_LABEL (default_case)); |
828 | edge e; | |
726a989a | 829 | int i = 0; |
b6e99746 MJ |
830 | |
831 | gcc_assert (CASE_LOW (default_case) == NULL_TREE); | |
832 | ||
fade902a SB |
833 | if (bb == info->final_bb) |
834 | e = find_edge (info->switch_bb, bb); | |
b6e99746 MJ |
835 | else |
836 | e = single_succ_edge (bb); | |
837 | ||
fade902a | 838 | for (gsi = gsi_start_phis (info->final_bb); !gsi_end_p (gsi); gsi_next (&gsi)) |
b6e99746 | 839 | { |
726a989a | 840 | gimple phi = gsi_stmt (gsi); |
b6e99746 MJ |
841 | tree val = PHI_ARG_DEF_FROM_EDGE (phi, e); |
842 | gcc_assert (val); | |
fade902a | 843 | info->default_values[i++] = val; |
b6e99746 MJ |
844 | } |
845 | } | |
846 | ||
847 | /* The following function populates the vectors in the constructors array with | |
848 | future contents of the static arrays. The vectors are populated in the | |
849 | order of phi nodes. SWTCH is the switch statement being converted. */ | |
850 | ||
851 | static void | |
fade902a | 852 | build_constructors (gimple swtch, struct switch_conv_info *info) |
b6e99746 | 853 | { |
726a989a | 854 | unsigned i, branch_num = gimple_switch_num_labels (swtch); |
fade902a | 855 | tree pos = info->range_min; |
b6e99746 | 856 | |
726a989a | 857 | for (i = 1; i < branch_num; i++) |
b6e99746 | 858 | { |
726a989a | 859 | tree cs = gimple_switch_label (swtch, i); |
b6e99746 MJ |
860 | basic_block bb = label_to_block (CASE_LABEL (cs)); |
861 | edge e; | |
726a989a RB |
862 | tree high; |
863 | gimple_stmt_iterator gsi; | |
b6e99746 MJ |
864 | int j; |
865 | ||
fade902a SB |
866 | if (bb == info->final_bb) |
867 | e = find_edge (info->switch_bb, bb); | |
b6e99746 MJ |
868 | else |
869 | e = single_succ_edge (bb); | |
870 | gcc_assert (e); | |
871 | ||
872 | while (tree_int_cst_lt (pos, CASE_LOW (cs))) | |
873 | { | |
874 | int k; | |
fade902a | 875 | for (k = 0; k < info->phi_count; k++) |
b6e99746 | 876 | { |
f32682ca | 877 | constructor_elt elt; |
b6e99746 | 878 | |
f32682ca | 879 | elt.index = int_const_binop (MINUS_EXPR, pos, info->range_min); |
d1f98542 RB |
880 | elt.value |
881 | = unshare_expr_without_location (info->default_values[k]); | |
9771b263 | 882 | info->constructors[k]->quick_push (elt); |
b6e99746 MJ |
883 | } |
884 | ||
d35936ab | 885 | pos = int_const_binop (PLUS_EXPR, pos, integer_one_node); |
b6e99746 | 886 | } |
b1ae1681 | 887 | gcc_assert (tree_int_cst_equal (pos, CASE_LOW (cs))); |
b6e99746 MJ |
888 | |
889 | j = 0; | |
890 | if (CASE_HIGH (cs)) | |
891 | high = CASE_HIGH (cs); | |
892 | else | |
b1ae1681 | 893 | high = CASE_LOW (cs); |
fade902a | 894 | for (gsi = gsi_start_phis (info->final_bb); |
726a989a | 895 | !gsi_end_p (gsi); gsi_next (&gsi)) |
b6e99746 | 896 | { |
726a989a | 897 | gimple phi = gsi_stmt (gsi); |
b6e99746 | 898 | tree val = PHI_ARG_DEF_FROM_EDGE (phi, e); |
7f2a9982 | 899 | tree low = CASE_LOW (cs); |
b6e99746 MJ |
900 | pos = CASE_LOW (cs); |
901 | ||
b8698a0f | 902 | do |
b6e99746 | 903 | { |
f32682ca | 904 | constructor_elt elt; |
b6e99746 | 905 | |
f32682ca | 906 | elt.index = int_const_binop (MINUS_EXPR, pos, info->range_min); |
d1f98542 | 907 | elt.value = unshare_expr_without_location (val); |
9771b263 | 908 | info->constructors[j]->quick_push (elt); |
b6e99746 | 909 | |
d35936ab | 910 | pos = int_const_binop (PLUS_EXPR, pos, integer_one_node); |
7156c8ab MJ |
911 | } while (!tree_int_cst_lt (high, pos) |
912 | && tree_int_cst_lt (low, pos)); | |
b6e99746 MJ |
913 | j++; |
914 | } | |
915 | } | |
916 | } | |
917 | ||
7156c8ab MJ |
918 | /* If all values in the constructor vector are the same, return the value. |
919 | Otherwise return NULL_TREE. Not supposed to be called for empty | |
920 | vectors. */ | |
921 | ||
922 | static tree | |
9771b263 | 923 | constructor_contains_same_values_p (vec<constructor_elt, va_gc> *vec) |
7156c8ab | 924 | { |
8e97bc2b | 925 | unsigned int i; |
7156c8ab | 926 | tree prev = NULL_TREE; |
8e97bc2b | 927 | constructor_elt *elt; |
7156c8ab | 928 | |
9771b263 | 929 | FOR_EACH_VEC_SAFE_ELT (vec, i, elt) |
7156c8ab | 930 | { |
7156c8ab MJ |
931 | if (!prev) |
932 | prev = elt->value; | |
933 | else if (!operand_equal_p (elt->value, prev, OEP_ONLY_CONST)) | |
934 | return NULL_TREE; | |
935 | } | |
936 | return prev; | |
937 | } | |
938 | ||
8e97bc2b JJ |
939 | /* Return type which should be used for array elements, either TYPE, |
940 | or for integral type some smaller integral type that can still hold | |
941 | all the constants. */ | |
942 | ||
943 | static tree | |
fade902a SB |
944 | array_value_type (gimple swtch, tree type, int num, |
945 | struct switch_conv_info *info) | |
8e97bc2b | 946 | { |
9771b263 | 947 | unsigned int i, len = vec_safe_length (info->constructors[num]); |
8e97bc2b JJ |
948 | constructor_elt *elt; |
949 | enum machine_mode mode; | |
950 | int sign = 0; | |
951 | tree smaller_type; | |
952 | ||
953 | if (!INTEGRAL_TYPE_P (type)) | |
954 | return type; | |
955 | ||
956 | mode = GET_CLASS_NARROWEST_MODE (GET_MODE_CLASS (TYPE_MODE (type))); | |
957 | if (GET_MODE_SIZE (TYPE_MODE (type)) <= GET_MODE_SIZE (mode)) | |
958 | return type; | |
959 | ||
960 | if (len < (optimize_bb_for_size_p (gimple_bb (swtch)) ? 2 : 32)) | |
961 | return type; | |
962 | ||
9771b263 | 963 | FOR_EACH_VEC_SAFE_ELT (info->constructors[num], i, elt) |
8e97bc2b JJ |
964 | { |
965 | double_int cst; | |
966 | ||
967 | if (TREE_CODE (elt->value) != INTEGER_CST) | |
968 | return type; | |
969 | ||
970 | cst = TREE_INT_CST (elt->value); | |
971 | while (1) | |
972 | { | |
973 | unsigned int prec = GET_MODE_BITSIZE (mode); | |
974 | if (prec > HOST_BITS_PER_WIDE_INT) | |
975 | return type; | |
976 | ||
27bcd47c | 977 | if (sign >= 0 && cst == cst.zext (prec)) |
8e97bc2b | 978 | { |
27bcd47c | 979 | if (sign == 0 && cst == cst.sext (prec)) |
8e97bc2b JJ |
980 | break; |
981 | sign = 1; | |
982 | break; | |
983 | } | |
27bcd47c | 984 | if (sign <= 0 && cst == cst.sext (prec)) |
8e97bc2b JJ |
985 | { |
986 | sign = -1; | |
987 | break; | |
988 | } | |
989 | ||
990 | if (sign == 1) | |
991 | sign = 0; | |
992 | ||
993 | mode = GET_MODE_WIDER_MODE (mode); | |
994 | if (mode == VOIDmode | |
995 | || GET_MODE_SIZE (mode) >= GET_MODE_SIZE (TYPE_MODE (type))) | |
996 | return type; | |
997 | } | |
998 | } | |
999 | ||
1000 | if (sign == 0) | |
1001 | sign = TYPE_UNSIGNED (type) ? 1 : -1; | |
1002 | smaller_type = lang_hooks.types.type_for_mode (mode, sign >= 0); | |
1003 | if (GET_MODE_SIZE (TYPE_MODE (type)) | |
1004 | <= GET_MODE_SIZE (TYPE_MODE (smaller_type))) | |
1005 | return type; | |
1006 | ||
1007 | return smaller_type; | |
1008 | } | |
1009 | ||
b6e99746 MJ |
1010 | /* Create an appropriate array type and declaration and assemble a static array |
1011 | variable. Also create a load statement that initializes the variable in | |
1012 | question with a value from the static array. SWTCH is the switch statement | |
1013 | being converted, NUM is the index to arrays of constructors, default values | |
1014 | and target SSA names for this particular array. ARR_INDEX_TYPE is the type | |
1015 | of the index of the new array, PHI is the phi node of the final BB that | |
1016 | corresponds to the value that will be loaded from the created array. TIDX | |
7156c8ab MJ |
1017 | is an ssa name of a temporary variable holding the index for loads from the |
1018 | new array. */ | |
b6e99746 MJ |
1019 | |
1020 | static void | |
726a989a | 1021 | build_one_array (gimple swtch, int num, tree arr_index_type, gimple phi, |
fade902a | 1022 | tree tidx, struct switch_conv_info *info) |
b6e99746 | 1023 | { |
7156c8ab | 1024 | tree name, cst; |
726a989a | 1025 | gimple load; |
7156c8ab | 1026 | gimple_stmt_iterator gsi = gsi_for_stmt (swtch); |
c2255bc4 | 1027 | location_t loc = gimple_location (swtch); |
b6e99746 | 1028 | |
fade902a | 1029 | gcc_assert (info->default_values[num]); |
b6e99746 | 1030 | |
070ecdfd | 1031 | name = copy_ssa_name (PHI_RESULT (phi), NULL); |
fade902a | 1032 | info->target_inbound_names[num] = name; |
b6e99746 | 1033 | |
fade902a | 1034 | cst = constructor_contains_same_values_p (info->constructors[num]); |
7156c8ab MJ |
1035 | if (cst) |
1036 | load = gimple_build_assign (name, cst); | |
1037 | else | |
1038 | { | |
8e97bc2b | 1039 | tree array_type, ctor, decl, value_type, fetch, default_type; |
7156c8ab | 1040 | |
fade902a SB |
1041 | default_type = TREE_TYPE (info->default_values[num]); |
1042 | value_type = array_value_type (swtch, default_type, num, info); | |
7156c8ab | 1043 | array_type = build_array_type (value_type, arr_index_type); |
8e97bc2b JJ |
1044 | if (default_type != value_type) |
1045 | { | |
1046 | unsigned int i; | |
1047 | constructor_elt *elt; | |
1048 | ||
9771b263 | 1049 | FOR_EACH_VEC_SAFE_ELT (info->constructors[num], i, elt) |
8e97bc2b JJ |
1050 | elt->value = fold_convert (value_type, elt->value); |
1051 | } | |
fade902a | 1052 | ctor = build_constructor (array_type, info->constructors[num]); |
7156c8ab | 1053 | TREE_CONSTANT (ctor) = true; |
5f7ae6b6 | 1054 | TREE_STATIC (ctor) = true; |
7156c8ab | 1055 | |
c2255bc4 | 1056 | decl = build_decl (loc, VAR_DECL, NULL_TREE, array_type); |
7156c8ab MJ |
1057 | TREE_STATIC (decl) = 1; |
1058 | DECL_INITIAL (decl) = ctor; | |
1059 | ||
1060 | DECL_NAME (decl) = create_tmp_var_name ("CSWTCH"); | |
1061 | DECL_ARTIFICIAL (decl) = 1; | |
1062 | TREE_CONSTANT (decl) = 1; | |
2e3b4885 | 1063 | TREE_READONLY (decl) = 1; |
7156c8ab MJ |
1064 | varpool_finalize_decl (decl); |
1065 | ||
1066 | fetch = build4 (ARRAY_REF, value_type, decl, tidx, NULL_TREE, | |
1067 | NULL_TREE); | |
8e97bc2b JJ |
1068 | if (default_type != value_type) |
1069 | { | |
1070 | fetch = fold_convert (default_type, fetch); | |
1071 | fetch = force_gimple_operand_gsi (&gsi, fetch, true, NULL_TREE, | |
1072 | true, GSI_SAME_STMT); | |
1073 | } | |
7156c8ab MJ |
1074 | load = gimple_build_assign (name, fetch); |
1075 | } | |
b6e99746 | 1076 | |
726a989a | 1077 | gsi_insert_before (&gsi, load, GSI_SAME_STMT); |
7156c8ab | 1078 | update_stmt (load); |
fade902a | 1079 | info->arr_ref_last = load; |
b6e99746 MJ |
1080 | } |
1081 | ||
1082 | /* Builds and initializes static arrays initialized with values gathered from | |
1083 | the SWTCH switch statement. Also creates statements that load values from | |
1084 | them. */ | |
1085 | ||
1086 | static void | |
fade902a | 1087 | build_arrays (gimple swtch, struct switch_conv_info *info) |
b6e99746 MJ |
1088 | { |
1089 | tree arr_index_type; | |
83d5977e | 1090 | tree tidx, sub, utype; |
726a989a RB |
1091 | gimple stmt; |
1092 | gimple_stmt_iterator gsi; | |
b6e99746 | 1093 | int i; |
db3927fb | 1094 | location_t loc = gimple_location (swtch); |
b6e99746 | 1095 | |
726a989a | 1096 | gsi = gsi_for_stmt (swtch); |
04e78aa9 | 1097 | |
edb9b69e | 1098 | /* Make sure we do not generate arithmetics in a subrange. */ |
fade902a | 1099 | utype = TREE_TYPE (info->index_expr); |
edb9b69e JJ |
1100 | if (TREE_TYPE (utype)) |
1101 | utype = lang_hooks.types.type_for_mode (TYPE_MODE (TREE_TYPE (utype)), 1); | |
1102 | else | |
1103 | utype = lang_hooks.types.type_for_mode (TYPE_MODE (utype), 1); | |
1104 | ||
fade902a | 1105 | arr_index_type = build_index_type (info->range_size); |
83d5977e | 1106 | tidx = make_ssa_name (utype, NULL); |
edb9b69e | 1107 | sub = fold_build2_loc (loc, MINUS_EXPR, utype, |
fade902a SB |
1108 | fold_convert_loc (loc, utype, info->index_expr), |
1109 | fold_convert_loc (loc, utype, info->range_min)); | |
fae1034e | 1110 | sub = force_gimple_operand_gsi (&gsi, sub, |
726a989a RB |
1111 | false, NULL, true, GSI_SAME_STMT); |
1112 | stmt = gimple_build_assign (tidx, sub); | |
b6e99746 | 1113 | |
726a989a | 1114 | gsi_insert_before (&gsi, stmt, GSI_SAME_STMT); |
7156c8ab | 1115 | update_stmt (stmt); |
fade902a | 1116 | info->arr_ref_first = stmt; |
b6e99746 | 1117 | |
fade902a | 1118 | for (gsi = gsi_start_phis (info->final_bb), i = 0; |
726a989a | 1119 | !gsi_end_p (gsi); gsi_next (&gsi), i++) |
fade902a | 1120 | build_one_array (swtch, i, arr_index_type, gsi_stmt (gsi), tidx, info); |
b6e99746 MJ |
1121 | } |
1122 | ||
1123 | /* Generates and appropriately inserts loads of default values at the position | |
1124 | given by BSI. Returns the last inserted statement. */ | |
1125 | ||
726a989a | 1126 | static gimple |
fade902a | 1127 | gen_def_assigns (gimple_stmt_iterator *gsi, struct switch_conv_info *info) |
b6e99746 MJ |
1128 | { |
1129 | int i; | |
726a989a | 1130 | gimple assign = NULL; |
b6e99746 | 1131 | |
fade902a | 1132 | for (i = 0; i < info->phi_count; i++) |
b6e99746 | 1133 | { |
070ecdfd | 1134 | tree name = copy_ssa_name (info->target_inbound_names[i], NULL); |
fade902a SB |
1135 | info->target_outbound_names[i] = name; |
1136 | assign = gimple_build_assign (name, info->default_values[i]); | |
726a989a | 1137 | gsi_insert_before (gsi, assign, GSI_SAME_STMT); |
7156c8ab | 1138 | update_stmt (assign); |
b6e99746 MJ |
1139 | } |
1140 | return assign; | |
1141 | } | |
1142 | ||
1143 | /* Deletes the unused bbs and edges that now contain the switch statement and | |
1144 | its empty branch bbs. BBD is the now dead BB containing the original switch | |
1145 | statement, FINAL is the last BB of the converted switch statement (in terms | |
1146 | of succession). */ | |
1147 | ||
1148 | static void | |
1149 | prune_bbs (basic_block bbd, basic_block final) | |
1150 | { | |
1151 | edge_iterator ei; | |
1152 | edge e; | |
1153 | ||
1154 | for (ei = ei_start (bbd->succs); (e = ei_safe_edge (ei)); ) | |
1155 | { | |
1156 | basic_block bb; | |
1157 | bb = e->dest; | |
1158 | remove_edge (e); | |
1159 | if (bb != final) | |
1160 | delete_basic_block (bb); | |
1161 | } | |
1162 | delete_basic_block (bbd); | |
1163 | } | |
1164 | ||
1165 | /* Add values to phi nodes in final_bb for the two new edges. E1F is the edge | |
1166 | from the basic block loading values from an array and E2F from the basic | |
1167 | block loading default values. BBF is the last switch basic block (see the | |
1168 | bbf description in the comment below). */ | |
1169 | ||
1170 | static void | |
fade902a SB |
1171 | fix_phi_nodes (edge e1f, edge e2f, basic_block bbf, |
1172 | struct switch_conv_info *info) | |
b6e99746 | 1173 | { |
726a989a | 1174 | gimple_stmt_iterator gsi; |
b6e99746 MJ |
1175 | int i; |
1176 | ||
726a989a RB |
1177 | for (gsi = gsi_start_phis (bbf), i = 0; |
1178 | !gsi_end_p (gsi); gsi_next (&gsi), i++) | |
b6e99746 | 1179 | { |
726a989a | 1180 | gimple phi = gsi_stmt (gsi); |
9e227d60 DC |
1181 | add_phi_arg (phi, info->target_inbound_names[i], e1f, UNKNOWN_LOCATION); |
1182 | add_phi_arg (phi, info->target_outbound_names[i], e2f, UNKNOWN_LOCATION); | |
b6e99746 | 1183 | } |
b6e99746 MJ |
1184 | } |
1185 | ||
1186 | /* Creates a check whether the switch expression value actually falls into the | |
1187 | range given by all the cases. If it does not, the temporaries are loaded | |
1188 | with default values instead. SWTCH is the switch statement being converted. | |
1189 | ||
1190 | bb0 is the bb with the switch statement, however, we'll end it with a | |
1191 | condition instead. | |
1192 | ||
1193 | bb1 is the bb to be used when the range check went ok. It is derived from | |
1194 | the switch BB | |
1195 | ||
1196 | bb2 is the bb taken when the expression evaluated outside of the range | |
1197 | covered by the created arrays. It is populated by loads of default | |
1198 | values. | |
1199 | ||
1200 | bbF is a fall through for both bb1 and bb2 and contains exactly what | |
1201 | originally followed the switch statement. | |
1202 | ||
1203 | bbD contains the switch statement (in the end). It is unreachable but we | |
1204 | still need to strip off its edges. | |
1205 | */ | |
1206 | ||
1207 | static void | |
fade902a | 1208 | gen_inbound_check (gimple swtch, struct switch_conv_info *info) |
b6e99746 | 1209 | { |
c2255bc4 AH |
1210 | tree label_decl1 = create_artificial_label (UNKNOWN_LOCATION); |
1211 | tree label_decl2 = create_artificial_label (UNKNOWN_LOCATION); | |
1212 | tree label_decl3 = create_artificial_label (UNKNOWN_LOCATION); | |
726a989a | 1213 | gimple label1, label2, label3; |
edb9b69e | 1214 | tree utype, tidx; |
b6e99746 MJ |
1215 | tree bound; |
1216 | ||
726a989a | 1217 | gimple cond_stmt; |
b6e99746 | 1218 | |
726a989a RB |
1219 | gimple last_assign; |
1220 | gimple_stmt_iterator gsi; | |
b6e99746 MJ |
1221 | basic_block bb0, bb1, bb2, bbf, bbd; |
1222 | edge e01, e02, e21, e1d, e1f, e2f; | |
db3927fb | 1223 | location_t loc = gimple_location (swtch); |
b6e99746 | 1224 | |
fade902a | 1225 | gcc_assert (info->default_values); |
6ab1ab14 | 1226 | |
726a989a | 1227 | bb0 = gimple_bb (swtch); |
b6e99746 | 1228 | |
fade902a | 1229 | tidx = gimple_assign_lhs (info->arr_ref_first); |
edb9b69e | 1230 | utype = TREE_TYPE (tidx); |
145544ab | 1231 | |
b6e99746 | 1232 | /* (end of) block 0 */ |
fade902a | 1233 | gsi = gsi_for_stmt (info->arr_ref_first); |
edb9b69e | 1234 | gsi_next (&gsi); |
b6e99746 | 1235 | |
fade902a | 1236 | bound = fold_convert_loc (loc, utype, info->range_size); |
edb9b69e | 1237 | cond_stmt = gimple_build_cond (LE_EXPR, tidx, bound, NULL_TREE, NULL_TREE); |
726a989a | 1238 | gsi_insert_before (&gsi, cond_stmt, GSI_SAME_STMT); |
7156c8ab | 1239 | update_stmt (cond_stmt); |
b6e99746 MJ |
1240 | |
1241 | /* block 2 */ | |
726a989a RB |
1242 | label2 = gimple_build_label (label_decl2); |
1243 | gsi_insert_before (&gsi, label2, GSI_SAME_STMT); | |
fade902a | 1244 | last_assign = gen_def_assigns (&gsi, info); |
b6e99746 MJ |
1245 | |
1246 | /* block 1 */ | |
726a989a RB |
1247 | label1 = gimple_build_label (label_decl1); |
1248 | gsi_insert_before (&gsi, label1, GSI_SAME_STMT); | |
b6e99746 MJ |
1249 | |
1250 | /* block F */ | |
fade902a | 1251 | gsi = gsi_start_bb (info->final_bb); |
726a989a RB |
1252 | label3 = gimple_build_label (label_decl3); |
1253 | gsi_insert_before (&gsi, label3, GSI_SAME_STMT); | |
b6e99746 MJ |
1254 | |
1255 | /* cfg fix */ | |
726a989a | 1256 | e02 = split_block (bb0, cond_stmt); |
b6e99746 MJ |
1257 | bb2 = e02->dest; |
1258 | ||
1259 | e21 = split_block (bb2, last_assign); | |
1260 | bb1 = e21->dest; | |
1261 | remove_edge (e21); | |
1262 | ||
fade902a | 1263 | e1d = split_block (bb1, info->arr_ref_last); |
b6e99746 MJ |
1264 | bbd = e1d->dest; |
1265 | remove_edge (e1d); | |
1266 | ||
1267 | /* flags and profiles of the edge for in-range values */ | |
1268 | e01 = make_edge (bb0, bb1, EDGE_TRUE_VALUE); | |
fade902a SB |
1269 | e01->probability = REG_BR_PROB_BASE - info->default_prob; |
1270 | e01->count = info->other_count; | |
b6e99746 MJ |
1271 | |
1272 | /* flags and profiles of the edge taking care of out-of-range values */ | |
1273 | e02->flags &= ~EDGE_FALLTHRU; | |
1274 | e02->flags |= EDGE_FALSE_VALUE; | |
fade902a SB |
1275 | e02->probability = info->default_prob; |
1276 | e02->count = info->default_count; | |
b6e99746 | 1277 | |
fade902a | 1278 | bbf = info->final_bb; |
b6e99746 MJ |
1279 | |
1280 | e1f = make_edge (bb1, bbf, EDGE_FALLTHRU); | |
1281 | e1f->probability = REG_BR_PROB_BASE; | |
fade902a | 1282 | e1f->count = info->other_count; |
b6e99746 MJ |
1283 | |
1284 | e2f = make_edge (bb2, bbf, EDGE_FALLTHRU); | |
1285 | e2f->probability = REG_BR_PROB_BASE; | |
fade902a | 1286 | e2f->count = info->default_count; |
b6e99746 MJ |
1287 | |
1288 | /* frequencies of the new BBs */ | |
1289 | bb1->frequency = EDGE_FREQUENCY (e01); | |
1290 | bb2->frequency = EDGE_FREQUENCY (e02); | |
1291 | bbf->frequency = EDGE_FREQUENCY (e1f) + EDGE_FREQUENCY (e2f); | |
1292 | ||
6ab1ab14 SB |
1293 | /* Tidy blocks that have become unreachable. */ |
1294 | prune_bbs (bbd, info->final_bb); | |
b6e99746 | 1295 | |
6ab1ab14 | 1296 | /* Fixup the PHI nodes in bbF. */ |
fade902a | 1297 | fix_phi_nodes (e1f, e2f, bbf, info); |
b6e99746 | 1298 | |
6ab1ab14 SB |
1299 | /* Fix the dominator tree, if it is available. */ |
1300 | if (dom_info_available_p (CDI_DOMINATORS)) | |
1301 | { | |
9771b263 | 1302 | vec<basic_block> bbs_to_fix_dom; |
6ab1ab14 SB |
1303 | |
1304 | set_immediate_dominator (CDI_DOMINATORS, bb1, bb0); | |
1305 | set_immediate_dominator (CDI_DOMINATORS, bb2, bb0); | |
531b10fc | 1306 | if (! get_immediate_dominator (CDI_DOMINATORS, bbf)) |
6ab1ab14 SB |
1307 | /* If bbD was the immediate dominator ... */ |
1308 | set_immediate_dominator (CDI_DOMINATORS, bbf, bb0); | |
1309 | ||
9771b263 DN |
1310 | bbs_to_fix_dom.create (4); |
1311 | bbs_to_fix_dom.quick_push (bb0); | |
1312 | bbs_to_fix_dom.quick_push (bb1); | |
1313 | bbs_to_fix_dom.quick_push (bb2); | |
1314 | bbs_to_fix_dom.quick_push (bbf); | |
6ab1ab14 SB |
1315 | |
1316 | iterate_fix_dominators (CDI_DOMINATORS, bbs_to_fix_dom, true); | |
9771b263 | 1317 | bbs_to_fix_dom.release (); |
6ab1ab14 | 1318 | } |
b6e99746 MJ |
1319 | } |
1320 | ||
1321 | /* The following function is invoked on every switch statement (the current one | |
1322 | is given in SWTCH) and runs the individual phases of switch conversion on it | |
fade902a SB |
1323 | one after another until one fails or the conversion is completed. |
1324 | Returns NULL on success, or a pointer to a string with the reason why the | |
1325 | conversion failed. */ | |
b6e99746 | 1326 | |
fade902a | 1327 | static const char * |
726a989a | 1328 | process_switch (gimple swtch) |
b6e99746 | 1329 | { |
fade902a | 1330 | struct switch_conv_info info; |
b6e99746 | 1331 | |
238065a7 SB |
1332 | /* Group case labels so that we get the right results from the heuristics |
1333 | that decide on the code generation approach for this switch. */ | |
1334 | group_case_labels_stmt (swtch); | |
1335 | ||
1336 | /* If this switch is now a degenerate case with only a default label, | |
1337 | there is nothing left for us to do. */ | |
1338 | if (gimple_switch_num_labels (swtch) < 2) | |
1339 | return "switch is a degenerate case"; | |
886cd84f SB |
1340 | |
1341 | collect_switch_conv_info (swtch, &info); | |
1342 | ||
1343 | /* No error markers should reach here (they should be filtered out | |
1344 | during gimplification). */ | |
1345 | gcc_checking_assert (TREE_TYPE (info.index_expr) != error_mark_node); | |
1346 | ||
531b10fc SB |
1347 | /* A switch on a constant should have been optimized in tree-cfg-cleanup. */ |
1348 | gcc_checking_assert (! TREE_CONSTANT (info.index_expr)); | |
886cd84f | 1349 | |
531b10fc | 1350 | if (info.uniq <= MAX_CASE_BIT_TESTS) |
886cd84f | 1351 | { |
531b10fc | 1352 | if (expand_switch_using_bit_tests_p (info.range_size, |
886cd84f | 1353 | info.uniq, info.count)) |
531b10fc SB |
1354 | { |
1355 | if (dump_file) | |
1356 | fputs (" expanding as bit test is preferable\n", dump_file); | |
1357 | emit_case_bit_tests (swtch, info.index_expr, | |
1358 | info.range_min, info.range_size); | |
a9e0d843 RB |
1359 | if (current_loops) |
1360 | loops_state_set (LOOPS_NEED_FIXUP); | |
531b10fc SB |
1361 | return NULL; |
1362 | } | |
1363 | ||
1364 | if (info.uniq <= 2) | |
1365 | /* This will be expanded as a decision tree in stmt.c:expand_case. */ | |
1366 | return " expanding as jumps is preferable"; | |
886cd84f | 1367 | } |
b6e99746 | 1368 | |
531b10fc SB |
1369 | /* If there is no common successor, we cannot do the transformation. */ |
1370 | if (! info.final_bb) | |
1371 | return "no common successor to all case label target blocks found"; | |
1372 | ||
b6e99746 | 1373 | /* Check the case label values are within reasonable range: */ |
886cd84f | 1374 | if (!check_range (&info)) |
fade902a SB |
1375 | { |
1376 | gcc_assert (info.reason); | |
1377 | return info.reason; | |
1378 | } | |
b6e99746 MJ |
1379 | |
1380 | /* For all the cases, see whether they are empty, the assignments they | |
1381 | represent constant and so on... */ | |
886cd84f | 1382 | if (! check_all_empty_except_final (&info)) |
8e97bc2b | 1383 | { |
886cd84f SB |
1384 | gcc_assert (info.reason); |
1385 | return info.reason; | |
8e97bc2b | 1386 | } |
fade902a SB |
1387 | if (!check_final_bb (&info)) |
1388 | { | |
1389 | gcc_assert (info.reason); | |
1390 | return info.reason; | |
1391 | } | |
b6e99746 MJ |
1392 | |
1393 | /* At this point all checks have passed and we can proceed with the | |
1394 | transformation. */ | |
1395 | ||
fade902a | 1396 | create_temp_arrays (&info); |
fd8d363e | 1397 | gather_default_values (gimple_switch_default_label (swtch), &info); |
fade902a | 1398 | build_constructors (swtch, &info); |
b6e99746 | 1399 | |
fade902a SB |
1400 | build_arrays (swtch, &info); /* Build the static arrays and assignments. */ |
1401 | gen_inbound_check (swtch, &info); /* Build the bounds check. */ | |
b6e99746 MJ |
1402 | |
1403 | /* Cleanup: */ | |
fade902a SB |
1404 | free_temp_arrays (&info); |
1405 | return NULL; | |
b6e99746 MJ |
1406 | } |
1407 | ||
1408 | /* The main function of the pass scans statements for switches and invokes | |
1409 | process_switch on them. */ | |
1410 | ||
1411 | static unsigned int | |
1412 | do_switchconv (void) | |
1413 | { | |
1414 | basic_block bb; | |
1415 | ||
1416 | FOR_EACH_BB (bb) | |
1417 | { | |
fade902a | 1418 | const char *failure_reason; |
726a989a RB |
1419 | gimple stmt = last_stmt (bb); |
1420 | if (stmt && gimple_code (stmt) == GIMPLE_SWITCH) | |
b6e99746 | 1421 | { |
b6e99746 MJ |
1422 | if (dump_file) |
1423 | { | |
726a989a RB |
1424 | expanded_location loc = expand_location (gimple_location (stmt)); |
1425 | ||
b6e99746 MJ |
1426 | fprintf (dump_file, "beginning to process the following " |
1427 | "SWITCH statement (%s:%d) : ------- \n", | |
1428 | loc.file, loc.line); | |
726a989a | 1429 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); |
edb30094 | 1430 | putc ('\n', dump_file); |
b6e99746 MJ |
1431 | } |
1432 | ||
fade902a SB |
1433 | failure_reason = process_switch (stmt); |
1434 | if (! failure_reason) | |
b6e99746 MJ |
1435 | { |
1436 | if (dump_file) | |
1437 | { | |
edb30094 UB |
1438 | fputs ("Switch converted\n", dump_file); |
1439 | fputs ("--------------------------------\n", dump_file); | |
b6e99746 | 1440 | } |
531b10fc SB |
1441 | |
1442 | /* Make no effort to update the post-dominator tree. It is actually not | |
1443 | that hard for the transformations we have performed, but it is not | |
1444 | supported by iterate_fix_dominators. */ | |
1445 | free_dominance_info (CDI_POST_DOMINATORS); | |
b6e99746 MJ |
1446 | } |
1447 | else | |
1448 | { | |
1449 | if (dump_file) | |
1450 | { | |
edb30094 | 1451 | fputs ("Bailing out - ", dump_file); |
fade902a SB |
1452 | fputs (failure_reason, dump_file); |
1453 | fputs ("\n--------------------------------\n", dump_file); | |
b6e99746 MJ |
1454 | } |
1455 | } | |
1456 | } | |
1457 | } | |
1458 | ||
1459 | return 0; | |
1460 | } | |
1461 | ||
1462 | /* The pass gate. */ | |
1463 | ||
1464 | static bool | |
1465 | switchconv_gate (void) | |
1466 | { | |
1467 | return flag_tree_switch_conversion != 0; | |
1468 | } | |
1469 | ||
27a4cd48 DM |
1470 | namespace { |
1471 | ||
1472 | const pass_data pass_data_convert_switch = | |
b6e99746 | 1473 | { |
27a4cd48 DM |
1474 | GIMPLE_PASS, /* type */ |
1475 | "switchconv", /* name */ | |
1476 | OPTGROUP_NONE, /* optinfo_flags */ | |
1477 | true, /* has_gate */ | |
1478 | true, /* has_execute */ | |
1479 | TV_TREE_SWITCH_CONVERSION, /* tv_id */ | |
1480 | ( PROP_cfg | PROP_ssa ), /* properties_required */ | |
1481 | 0, /* properties_provided */ | |
1482 | 0, /* properties_destroyed */ | |
1483 | 0, /* todo_flags_start */ | |
1484 | ( TODO_update_ssa | TODO_verify_ssa | |
1485 | | TODO_verify_stmts | |
1486 | | TODO_verify_flow ), /* todo_flags_finish */ | |
b6e99746 | 1487 | }; |
27a4cd48 DM |
1488 | |
1489 | class pass_convert_switch : public gimple_opt_pass | |
1490 | { | |
1491 | public: | |
c3284718 RS |
1492 | pass_convert_switch (gcc::context *ctxt) |
1493 | : gimple_opt_pass (pass_data_convert_switch, ctxt) | |
27a4cd48 DM |
1494 | {} |
1495 | ||
1496 | /* opt_pass methods: */ | |
1497 | bool gate () { return switchconv_gate (); } | |
1498 | unsigned int execute () { return do_switchconv (); } | |
1499 | ||
1500 | }; // class pass_convert_switch | |
1501 | ||
1502 | } // anon namespace | |
1503 | ||
1504 | gimple_opt_pass * | |
1505 | make_pass_convert_switch (gcc::context *ctxt) | |
1506 | { | |
1507 | return new pass_convert_switch (ctxt); | |
1508 | } |