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Commit | Line | Data |
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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" | |
d8a2d370 DN |
33 | #include "varasm.h" |
34 | #include "stor-layout.h" | |
531b10fc | 35 | #include "basic-block.h" |
2fb9a547 AM |
36 | #include "tree-ssa-alias.h" |
37 | #include "internal-fn.h" | |
38 | #include "gimple-expr.h" | |
39 | #include "is-a.h" | |
18f429e2 | 40 | #include "gimple.h" |
45b0be94 | 41 | #include "gimplify.h" |
5be5c238 | 42 | #include "gimple-iterator.h" |
18f429e2 | 43 | #include "gimplify-me.h" |
442b4905 AM |
44 | #include "gimple-ssa.h" |
45 | #include "cgraph.h" | |
46 | #include "tree-cfg.h" | |
47 | #include "tree-phinodes.h" | |
d8a2d370 | 48 | #include "stringpool.h" |
442b4905 | 49 | #include "tree-ssanames.h" |
531b10fc SB |
50 | #include "tree-pass.h" |
51 | #include "gimple-pretty-print.h" | |
a9e0d843 | 52 | #include "cfgloop.h" |
7ee2468b SB |
53 | |
54 | /* ??? For lang_hooks.types.type_for_mode, but is there a word_mode | |
55 | type in the GIMPLE type system that is language-independent? */ | |
531b10fc SB |
56 | #include "langhooks.h" |
57 | ||
58 | /* Need to include expr.h and optabs.h for lshift_cheap_p. */ | |
59 | #include "expr.h" | |
60 | #include "optabs.h" | |
61 | \f | |
62 | /* Maximum number of case bit tests. | |
63 | FIXME: This should be derived from PARAM_CASE_VALUES_THRESHOLD and | |
64 | targetm.case_values_threshold(), or be its own param. */ | |
65 | #define MAX_CASE_BIT_TESTS 3 | |
66 | ||
67 | /* Split the basic block at the statement pointed to by GSIP, and insert | |
68 | a branch to the target basic block of E_TRUE conditional on tree | |
69 | expression COND. | |
70 | ||
71 | It is assumed that there is already an edge from the to-be-split | |
72 | basic block to E_TRUE->dest block. This edge is removed, and the | |
73 | profile information on the edge is re-used for the new conditional | |
74 | jump. | |
75 | ||
76 | The CFG is updated. The dominator tree will not be valid after | |
77 | this transformation, but the immediate dominators are updated if | |
78 | UPDATE_DOMINATORS is true. | |
79 | ||
80 | Returns the newly created basic block. */ | |
81 | ||
82 | static basic_block | |
83 | hoist_edge_and_branch_if_true (gimple_stmt_iterator *gsip, | |
84 | tree cond, edge e_true, | |
85 | bool update_dominators) | |
86 | { | |
87 | tree tmp; | |
88 | gimple cond_stmt; | |
89 | edge e_false; | |
90 | basic_block new_bb, split_bb = gsi_bb (*gsip); | |
91 | bool dominated_e_true = false; | |
92 | ||
93 | gcc_assert (e_true->src == split_bb); | |
94 | ||
95 | if (update_dominators | |
96 | && get_immediate_dominator (CDI_DOMINATORS, e_true->dest) == split_bb) | |
97 | dominated_e_true = true; | |
98 | ||
99 | tmp = force_gimple_operand_gsi (gsip, cond, /*simple=*/true, NULL, | |
100 | /*before=*/true, GSI_SAME_STMT); | |
101 | cond_stmt = gimple_build_cond_from_tree (tmp, NULL_TREE, NULL_TREE); | |
102 | gsi_insert_before (gsip, cond_stmt, GSI_SAME_STMT); | |
103 | ||
104 | e_false = split_block (split_bb, cond_stmt); | |
105 | new_bb = e_false->dest; | |
106 | redirect_edge_pred (e_true, split_bb); | |
107 | ||
108 | e_true->flags &= ~EDGE_FALLTHRU; | |
109 | e_true->flags |= EDGE_TRUE_VALUE; | |
110 | ||
111 | e_false->flags &= ~EDGE_FALLTHRU; | |
112 | e_false->flags |= EDGE_FALSE_VALUE; | |
113 | e_false->probability = REG_BR_PROB_BASE - e_true->probability; | |
114 | e_false->count = split_bb->count - e_true->count; | |
115 | new_bb->count = e_false->count; | |
116 | ||
117 | if (update_dominators) | |
118 | { | |
119 | if (dominated_e_true) | |
120 | set_immediate_dominator (CDI_DOMINATORS, e_true->dest, split_bb); | |
121 | set_immediate_dominator (CDI_DOMINATORS, e_false->dest, split_bb); | |
122 | } | |
123 | ||
124 | return new_bb; | |
125 | } | |
126 | ||
127 | ||
128 | /* Determine whether "1 << x" is relatively cheap in word_mode. */ | |
129 | /* FIXME: This is the function that we need rtl.h and optabs.h for. | |
130 | This function (and similar RTL-related cost code in e.g. IVOPTS) should | |
131 | be moved to some kind of interface file for GIMPLE/RTL interactions. */ | |
132 | static bool | |
133 | lshift_cheap_p (void) | |
134 | { | |
135 | /* FIXME: This should be made target dependent via this "this_target" | |
136 | mechanism, similar to e.g. can_copy_init_p in gcse.c. */ | |
137 | static bool init[2] = {false, false}; | |
138 | static bool cheap[2] = {true, true}; | |
139 | bool speed_p; | |
140 | ||
141 | /* If the targer has no lshift in word_mode, the operation will most | |
142 | probably not be cheap. ??? Does GCC even work for such targets? */ | |
143 | if (optab_handler (ashl_optab, word_mode) == CODE_FOR_nothing) | |
144 | return false; | |
145 | ||
146 | speed_p = optimize_insn_for_speed_p (); | |
147 | ||
148 | if (!init[speed_p]) | |
149 | { | |
150 | rtx reg = gen_raw_REG (word_mode, 10000); | |
151 | int cost = set_src_cost (gen_rtx_ASHIFT (word_mode, const1_rtx, reg), | |
152 | speed_p); | |
153 | cheap[speed_p] = cost < COSTS_N_INSNS (MAX_CASE_BIT_TESTS); | |
154 | init[speed_p] = true; | |
155 | } | |
156 | ||
157 | return cheap[speed_p]; | |
158 | } | |
159 | ||
160 | /* Return true if a switch should be expanded as a bit test. | |
161 | RANGE is the difference between highest and lowest case. | |
162 | UNIQ is number of unique case node targets, not counting the default case. | |
163 | COUNT is the number of comparisons needed, not counting the default case. */ | |
164 | ||
165 | static bool | |
166 | expand_switch_using_bit_tests_p (tree range, | |
167 | unsigned int uniq, | |
168 | unsigned int count) | |
169 | { | |
170 | return (((uniq == 1 && count >= 3) | |
171 | || (uniq == 2 && count >= 5) | |
172 | || (uniq == 3 && count >= 6)) | |
173 | && lshift_cheap_p () | |
174 | && compare_tree_int (range, GET_MODE_BITSIZE (word_mode)) < 0 | |
175 | && compare_tree_int (range, 0) > 0); | |
176 | } | |
177 | \f | |
178 | /* Implement switch statements with bit tests | |
179 | ||
180 | A GIMPLE switch statement can be expanded to a short sequence of bit-wise | |
181 | comparisons. "switch(x)" is converted into "if ((1 << (x-MINVAL)) & CST)" | |
182 | where CST and MINVAL are integer constants. This is better than a series | |
183 | of compare-and-banch insns in some cases, e.g. we can implement: | |
184 | ||
185 | if ((x==4) || (x==6) || (x==9) || (x==11)) | |
186 | ||
187 | as a single bit test: | |
188 | ||
189 | if ((1<<x) & ((1<<4)|(1<<6)|(1<<9)|(1<<11))) | |
190 | ||
191 | This transformation is only applied if the number of case targets is small, | |
34540577 | 192 | if CST constains at least 3 bits, and "1 << x" is cheap. The bit tests are |
531b10fc SB |
193 | performed in "word_mode". |
194 | ||
195 | The following example shows the code the transformation generates: | |
196 | ||
197 | int bar(int x) | |
198 | { | |
199 | switch (x) | |
200 | { | |
201 | case '0': case '1': case '2': case '3': case '4': | |
202 | case '5': case '6': case '7': case '8': case '9': | |
203 | case 'A': case 'B': case 'C': case 'D': case 'E': | |
204 | case 'F': | |
205 | return 1; | |
206 | } | |
207 | return 0; | |
208 | } | |
209 | ||
210 | ==> | |
211 | ||
212 | bar (int x) | |
213 | { | |
214 | tmp1 = x - 48; | |
215 | if (tmp1 > (70 - 48)) goto L2; | |
216 | tmp2 = 1 << tmp1; | |
217 | tmp3 = 0b11111100000001111111111; | |
218 | if ((tmp2 & tmp3) != 0) goto L1 ; else goto L2; | |
219 | L1: | |
220 | return 1; | |
221 | L2: | |
222 | return 0; | |
223 | } | |
224 | ||
225 | TODO: There are still some improvements to this transformation that could | |
226 | be implemented: | |
227 | ||
228 | * A narrower mode than word_mode could be used if that is cheaper, e.g. | |
229 | for x86_64 where a narrower-mode shift may result in smaller code. | |
230 | ||
231 | * The compounded constant could be shifted rather than the one. The | |
232 | test would be either on the sign bit or on the least significant bit, | |
233 | depending on the direction of the shift. On some machines, the test | |
234 | for the branch would be free if the bit to test is already set by the | |
235 | shift operation. | |
236 | ||
237 | This transformation was contributed by Roger Sayle, see this e-mail: | |
238 | http://gcc.gnu.org/ml/gcc-patches/2003-01/msg01950.html | |
239 | */ | |
240 | ||
241 | /* A case_bit_test represents a set of case nodes that may be | |
242 | selected from using a bit-wise comparison. HI and LO hold | |
243 | the integer to be tested against, TARGET_EDGE contains the | |
244 | edge to the basic block to jump to upon success and BITS | |
245 | counts the number of case nodes handled by this test, | |
246 | typically the number of bits set in HI:LO. The LABEL field | |
247 | is used to quickly identify all cases in this set without | |
248 | looking at label_to_block for every case label. */ | |
249 | ||
250 | struct case_bit_test | |
251 | { | |
252 | HOST_WIDE_INT hi; | |
253 | HOST_WIDE_INT lo; | |
254 | edge target_edge; | |
255 | tree label; | |
256 | int bits; | |
257 | }; | |
258 | ||
259 | /* Comparison function for qsort to order bit tests by decreasing | |
260 | probability of execution. Our best guess comes from a measured | |
261 | profile. If the profile counts are equal, break even on the | |
262 | number of case nodes, i.e. the node with the most cases gets | |
263 | tested first. | |
264 | ||
265 | TODO: Actually this currently runs before a profile is available. | |
266 | Therefore the case-as-bit-tests transformation should be done | |
267 | later in the pass pipeline, or something along the lines of | |
268 | "Efficient and effective branch reordering using profile data" | |
269 | (Yang et. al., 2002) should be implemented (although, how good | |
270 | is a paper is called "Efficient and effective ..." when the | |
271 | latter is implied by the former, but oh well...). */ | |
272 | ||
273 | static int | |
274 | case_bit_test_cmp (const void *p1, const void *p2) | |
275 | { | |
276 | const struct case_bit_test *const d1 = (const struct case_bit_test *) p1; | |
277 | const struct case_bit_test *const d2 = (const struct case_bit_test *) p2; | |
278 | ||
279 | if (d2->target_edge->count != d1->target_edge->count) | |
280 | return d2->target_edge->count - d1->target_edge->count; | |
281 | if (d2->bits != d1->bits) | |
282 | return d2->bits - d1->bits; | |
283 | ||
284 | /* Stabilize the sort. */ | |
285 | return LABEL_DECL_UID (d2->label) - LABEL_DECL_UID (d1->label); | |
286 | } | |
287 | ||
288 | /* Expand a switch statement by a short sequence of bit-wise | |
289 | comparisons. "switch(x)" is effectively converted into | |
290 | "if ((1 << (x-MINVAL)) & CST)" where CST and MINVAL are | |
291 | integer constants. | |
292 | ||
293 | INDEX_EXPR is the value being switched on. | |
294 | ||
295 | MINVAL is the lowest case value of in the case nodes, | |
296 | and RANGE is highest value minus MINVAL. MINVAL and RANGE | |
297 | are not guaranteed to be of the same type as INDEX_EXPR | |
298 | (the gimplifier doesn't change the type of case label values, | |
299 | and MINVAL and RANGE are derived from those values). | |
300 | ||
301 | There *MUST* be MAX_CASE_BIT_TESTS or less unique case | |
302 | node targets. */ | |
303 | ||
304 | static void | |
305 | emit_case_bit_tests (gimple swtch, tree index_expr, | |
306 | tree minval, tree range) | |
307 | { | |
308 | struct case_bit_test test[MAX_CASE_BIT_TESTS]; | |
309 | unsigned int i, j, k; | |
310 | unsigned int count; | |
311 | ||
312 | basic_block switch_bb = gimple_bb (swtch); | |
313 | basic_block default_bb, new_default_bb, new_bb; | |
314 | edge default_edge; | |
315 | bool update_dom = dom_info_available_p (CDI_DOMINATORS); | |
316 | ||
6e1aa848 | 317 | vec<basic_block> bbs_to_fix_dom = vNULL; |
531b10fc SB |
318 | |
319 | tree index_type = TREE_TYPE (index_expr); | |
320 | tree unsigned_index_type = unsigned_type_for (index_type); | |
321 | unsigned int branch_num = gimple_switch_num_labels (swtch); | |
322 | ||
323 | gimple_stmt_iterator gsi; | |
324 | gimple shift_stmt; | |
325 | ||
326 | tree idx, tmp, csui; | |
327 | tree word_type_node = lang_hooks.types.type_for_mode (word_mode, 1); | |
328 | tree word_mode_zero = fold_convert (word_type_node, integer_zero_node); | |
329 | tree word_mode_one = fold_convert (word_type_node, integer_one_node); | |
330 | ||
331 | memset (&test, 0, sizeof (test)); | |
332 | ||
333 | /* Get the edge for the default case. */ | |
fd8d363e | 334 | tmp = gimple_switch_default_label (swtch); |
531b10fc SB |
335 | default_bb = label_to_block (CASE_LABEL (tmp)); |
336 | default_edge = find_edge (switch_bb, default_bb); | |
337 | ||
338 | /* Go through all case labels, and collect the case labels, profile | |
339 | counts, and other information we need to build the branch tests. */ | |
340 | count = 0; | |
341 | for (i = 1; i < branch_num; i++) | |
342 | { | |
343 | unsigned int lo, hi; | |
344 | tree cs = gimple_switch_label (swtch, i); | |
345 | tree label = CASE_LABEL (cs); | |
8166ff4d | 346 | edge e = find_edge (switch_bb, label_to_block (label)); |
531b10fc | 347 | for (k = 0; k < count; k++) |
8166ff4d | 348 | if (e == test[k].target_edge) |
531b10fc SB |
349 | break; |
350 | ||
351 | if (k == count) | |
352 | { | |
531b10fc SB |
353 | gcc_checking_assert (count < MAX_CASE_BIT_TESTS); |
354 | test[k].hi = 0; | |
355 | test[k].lo = 0; | |
356 | test[k].target_edge = e; | |
357 | test[k].label = label; | |
358 | test[k].bits = 1; | |
359 | count++; | |
360 | } | |
361 | else | |
362 | test[k].bits++; | |
363 | ||
386b1f1f RS |
364 | lo = tree_to_uhwi (int_const_binop (MINUS_EXPR, |
365 | CASE_LOW (cs), minval)); | |
531b10fc SB |
366 | if (CASE_HIGH (cs) == NULL_TREE) |
367 | hi = lo; | |
368 | else | |
386b1f1f RS |
369 | hi = tree_to_uhwi (int_const_binop (MINUS_EXPR, |
370 | CASE_HIGH (cs), minval)); | |
531b10fc SB |
371 | |
372 | for (j = lo; j <= hi; j++) | |
373 | if (j >= HOST_BITS_PER_WIDE_INT) | |
374 | test[k].hi |= (HOST_WIDE_INT) 1 << (j - HOST_BITS_PER_INT); | |
375 | else | |
376 | test[k].lo |= (HOST_WIDE_INT) 1 << j; | |
377 | } | |
378 | ||
c3284718 | 379 | qsort (test, count, sizeof (*test), case_bit_test_cmp); |
531b10fc SB |
380 | |
381 | /* We generate two jumps to the default case label. | |
382 | Split the default edge, so that we don't have to do any PHI node | |
383 | updating. */ | |
384 | new_default_bb = split_edge (default_edge); | |
385 | ||
386 | if (update_dom) | |
387 | { | |
9771b263 DN |
388 | bbs_to_fix_dom.create (10); |
389 | bbs_to_fix_dom.quick_push (switch_bb); | |
390 | bbs_to_fix_dom.quick_push (default_bb); | |
391 | bbs_to_fix_dom.quick_push (new_default_bb); | |
531b10fc SB |
392 | } |
393 | ||
394 | /* Now build the test-and-branch code. */ | |
395 | ||
396 | gsi = gsi_last_bb (switch_bb); | |
397 | ||
d9e408de TV |
398 | /* idx = (unsigned)x - minval. */ |
399 | idx = fold_convert (unsigned_index_type, index_expr); | |
400 | idx = fold_build2 (MINUS_EXPR, unsigned_index_type, idx, | |
401 | fold_convert (unsigned_index_type, minval)); | |
531b10fc SB |
402 | idx = force_gimple_operand_gsi (&gsi, idx, |
403 | /*simple=*/true, NULL_TREE, | |
404 | /*before=*/true, GSI_SAME_STMT); | |
405 | ||
406 | /* if (idx > range) goto default */ | |
407 | range = force_gimple_operand_gsi (&gsi, | |
408 | fold_convert (unsigned_index_type, range), | |
409 | /*simple=*/true, NULL_TREE, | |
410 | /*before=*/true, GSI_SAME_STMT); | |
411 | tmp = fold_build2 (GT_EXPR, boolean_type_node, idx, range); | |
412 | new_bb = hoist_edge_and_branch_if_true (&gsi, tmp, default_edge, update_dom); | |
413 | if (update_dom) | |
9771b263 | 414 | bbs_to_fix_dom.quick_push (new_bb); |
531b10fc SB |
415 | gcc_assert (gimple_bb (swtch) == new_bb); |
416 | gsi = gsi_last_bb (new_bb); | |
417 | ||
418 | /* Any blocks dominated by the GIMPLE_SWITCH, but that are not successors | |
419 | of NEW_BB, are still immediately dominated by SWITCH_BB. Make it so. */ | |
420 | if (update_dom) | |
421 | { | |
9771b263 | 422 | vec<basic_block> dom_bbs; |
531b10fc SB |
423 | basic_block dom_son; |
424 | ||
425 | dom_bbs = get_dominated_by (CDI_DOMINATORS, new_bb); | |
9771b263 | 426 | FOR_EACH_VEC_ELT (dom_bbs, i, dom_son) |
531b10fc SB |
427 | { |
428 | edge e = find_edge (new_bb, dom_son); | |
429 | if (e && single_pred_p (e->dest)) | |
430 | continue; | |
431 | set_immediate_dominator (CDI_DOMINATORS, dom_son, switch_bb); | |
9771b263 | 432 | bbs_to_fix_dom.safe_push (dom_son); |
531b10fc | 433 | } |
9771b263 | 434 | dom_bbs.release (); |
531b10fc SB |
435 | } |
436 | ||
437 | /* csui = (1 << (word_mode) idx) */ | |
83d5977e | 438 | csui = make_ssa_name (word_type_node, NULL); |
531b10fc SB |
439 | tmp = fold_build2 (LSHIFT_EXPR, word_type_node, word_mode_one, |
440 | fold_convert (word_type_node, idx)); | |
441 | tmp = force_gimple_operand_gsi (&gsi, tmp, | |
442 | /*simple=*/false, NULL_TREE, | |
443 | /*before=*/true, GSI_SAME_STMT); | |
444 | shift_stmt = gimple_build_assign (csui, tmp); | |
531b10fc SB |
445 | gsi_insert_before (&gsi, shift_stmt, GSI_SAME_STMT); |
446 | update_stmt (shift_stmt); | |
447 | ||
448 | /* for each unique set of cases: | |
449 | if (const & csui) goto target */ | |
450 | for (k = 0; k < count; k++) | |
451 | { | |
452 | tmp = build_int_cst_wide (word_type_node, test[k].lo, test[k].hi); | |
453 | tmp = fold_build2 (BIT_AND_EXPR, word_type_node, csui, tmp); | |
454 | tmp = force_gimple_operand_gsi (&gsi, tmp, | |
455 | /*simple=*/true, NULL_TREE, | |
456 | /*before=*/true, GSI_SAME_STMT); | |
457 | tmp = fold_build2 (NE_EXPR, boolean_type_node, tmp, word_mode_zero); | |
458 | new_bb = hoist_edge_and_branch_if_true (&gsi, tmp, test[k].target_edge, | |
459 | update_dom); | |
460 | if (update_dom) | |
9771b263 | 461 | bbs_to_fix_dom.safe_push (new_bb); |
531b10fc SB |
462 | gcc_assert (gimple_bb (swtch) == new_bb); |
463 | gsi = gsi_last_bb (new_bb); | |
464 | } | |
465 | ||
466 | /* We should have removed all edges now. */ | |
467 | gcc_assert (EDGE_COUNT (gsi_bb (gsi)->succs) == 0); | |
468 | ||
469 | /* If nothing matched, go to the default label. */ | |
470 | make_edge (gsi_bb (gsi), new_default_bb, EDGE_FALLTHRU); | |
471 | ||
472 | /* The GIMPLE_SWITCH is now redundant. */ | |
473 | gsi_remove (&gsi, true); | |
474 | ||
475 | if (update_dom) | |
476 | { | |
477 | /* Fix up the dominator tree. */ | |
478 | iterate_fix_dominators (CDI_DOMINATORS, bbs_to_fix_dom, true); | |
9771b263 | 479 | bbs_to_fix_dom.release (); |
531b10fc SB |
480 | } |
481 | } | |
482 | \f | |
b6e99746 MJ |
483 | /* |
484 | Switch initialization conversion | |
485 | ||
486 | The following pass changes simple initializations of scalars in a switch | |
fade902a SB |
487 | statement into initializations from a static array. Obviously, the values |
488 | must be constant and known at compile time and a default branch must be | |
b6e99746 MJ |
489 | provided. For example, the following code: |
490 | ||
491 | int a,b; | |
492 | ||
493 | switch (argc) | |
494 | { | |
495 | case 1: | |
496 | case 2: | |
497 | a_1 = 8; | |
498 | b_1 = 6; | |
499 | break; | |
500 | case 3: | |
501 | a_2 = 9; | |
502 | b_2 = 5; | |
503 | break; | |
504 | case 12: | |
505 | a_3 = 10; | |
506 | b_3 = 4; | |
507 | break; | |
508 | default: | |
509 | a_4 = 16; | |
510 | b_4 = 1; | |
886cd84f | 511 | break; |
b6e99746 MJ |
512 | } |
513 | a_5 = PHI <a_1, a_2, a_3, a_4> | |
514 | b_5 = PHI <b_1, b_2, b_3, b_4> | |
515 | ||
516 | ||
517 | is changed into: | |
518 | ||
519 | static const int = CSWTCH01[] = {6, 6, 5, 1, 1, 1, 1, 1, 1, 1, 1, 4}; | |
520 | static const int = CSWTCH02[] = {8, 8, 9, 16, 16, 16, 16, 16, 16, 16, | |
521 | 16, 16, 10}; | |
522 | ||
523 | if (((unsigned) argc) - 1 < 11) | |
524 | { | |
525 | a_6 = CSWTCH02[argc - 1]; | |
526 | b_6 = CSWTCH01[argc - 1]; | |
527 | } | |
528 | else | |
529 | { | |
530 | a_7 = 16; | |
531 | b_7 = 1; | |
532 | } | |
886cd84f SB |
533 | a_5 = PHI <a_6, a_7> |
534 | b_b = PHI <b_6, b_7> | |
b6e99746 MJ |
535 | |
536 | There are further constraints. Specifically, the range of values across all | |
537 | case labels must not be bigger than SWITCH_CONVERSION_BRANCH_RATIO (default | |
531b10fc | 538 | eight) times the number of the actual switch branches. |
b6e99746 | 539 | |
531b10fc SB |
540 | This transformation was contributed by Martin Jambor, see this e-mail: |
541 | http://gcc.gnu.org/ml/gcc-patches/2008-07/msg00011.html */ | |
b6e99746 MJ |
542 | |
543 | /* The main structure of the pass. */ | |
544 | struct switch_conv_info | |
545 | { | |
886cd84f | 546 | /* The expression used to decide the switch branch. */ |
b6e99746 MJ |
547 | tree index_expr; |
548 | ||
886cd84f SB |
549 | /* The following integer constants store the minimum and maximum value |
550 | covered by the case labels. */ | |
b6e99746 | 551 | tree range_min; |
886cd84f | 552 | tree range_max; |
b6e99746 | 553 | |
886cd84f SB |
554 | /* The difference between the above two numbers. Stored here because it |
555 | is used in all the conversion heuristics, as well as for some of the | |
556 | transformation, and it is expensive to re-compute it all the time. */ | |
b6e99746 MJ |
557 | tree range_size; |
558 | ||
886cd84f | 559 | /* Basic block that contains the actual GIMPLE_SWITCH. */ |
b6e99746 MJ |
560 | basic_block switch_bb; |
561 | ||
886cd84f SB |
562 | /* Basic block that is the target of the default case. */ |
563 | basic_block default_bb; | |
564 | ||
565 | /* The single successor block of all branches out of the GIMPLE_SWITCH, | |
566 | if such a block exists. Otherwise NULL. */ | |
b6e99746 MJ |
567 | basic_block final_bb; |
568 | ||
886cd84f SB |
569 | /* The probability of the default edge in the replaced switch. */ |
570 | int default_prob; | |
571 | ||
572 | /* The count of the default edge in the replaced switch. */ | |
573 | gcov_type default_count; | |
574 | ||
575 | /* Combined count of all other (non-default) edges in the replaced switch. */ | |
576 | gcov_type other_count; | |
577 | ||
b6e99746 MJ |
578 | /* Number of phi nodes in the final bb (that we'll be replacing). */ |
579 | int phi_count; | |
580 | ||
b1ae1681 | 581 | /* Array of default values, in the same order as phi nodes. */ |
b6e99746 MJ |
582 | tree *default_values; |
583 | ||
584 | /* Constructors of new static arrays. */ | |
9771b263 | 585 | vec<constructor_elt, va_gc> **constructors; |
b6e99746 MJ |
586 | |
587 | /* Array of ssa names that are initialized with a value from a new static | |
588 | array. */ | |
589 | tree *target_inbound_names; | |
590 | ||
591 | /* Array of ssa names that are initialized with the default value if the | |
592 | switch expression is out of range. */ | |
593 | tree *target_outbound_names; | |
594 | ||
b1ae1681 MJ |
595 | /* The first load statement that loads a temporary from a new static array. |
596 | */ | |
726a989a | 597 | gimple arr_ref_first; |
b6e99746 MJ |
598 | |
599 | /* The last load statement that loads a temporary from a new static array. */ | |
726a989a | 600 | gimple arr_ref_last; |
b6e99746 MJ |
601 | |
602 | /* String reason why the case wasn't a good candidate that is written to the | |
603 | dump file, if there is one. */ | |
604 | const char *reason; | |
8e97bc2b JJ |
605 | |
606 | /* Parameters for expand_switch_using_bit_tests. Should be computed | |
607 | the same way as in expand_case. */ | |
886cd84f SB |
608 | unsigned int uniq; |
609 | unsigned int count; | |
b6e99746 MJ |
610 | }; |
611 | ||
886cd84f | 612 | /* Collect information about GIMPLE_SWITCH statement SWTCH into INFO. */ |
b6e99746 | 613 | |
886cd84f SB |
614 | static void |
615 | collect_switch_conv_info (gimple swtch, struct switch_conv_info *info) | |
b6e99746 | 616 | { |
726a989a | 617 | unsigned int branch_num = gimple_switch_num_labels (swtch); |
886cd84f SB |
618 | tree min_case, max_case; |
619 | unsigned int count, i; | |
620 | edge e, e_default; | |
621 | edge_iterator ei; | |
622 | ||
623 | memset (info, 0, sizeof (*info)); | |
b6e99746 MJ |
624 | |
625 | /* The gimplifier has already sorted the cases by CASE_LOW and ensured there | |
fd8d363e SB |
626 | is a default label which is the first in the vector. |
627 | Collect the bits we can deduce from the CFG. */ | |
886cd84f SB |
628 | info->index_expr = gimple_switch_index (swtch); |
629 | info->switch_bb = gimple_bb (swtch); | |
630 | info->default_bb = | |
fd8d363e | 631 | label_to_block (CASE_LABEL (gimple_switch_default_label (swtch))); |
886cd84f SB |
632 | e_default = find_edge (info->switch_bb, info->default_bb); |
633 | info->default_prob = e_default->probability; | |
634 | info->default_count = e_default->count; | |
635 | FOR_EACH_EDGE (e, ei, info->switch_bb->succs) | |
636 | if (e != e_default) | |
637 | info->other_count += e->count; | |
b6e99746 | 638 | |
886cd84f SB |
639 | /* See if there is one common successor block for all branch |
640 | targets. If it exists, record it in FINAL_BB. */ | |
641 | FOR_EACH_EDGE (e, ei, info->switch_bb->succs) | |
642 | { | |
643 | if (! single_pred_p (e->dest)) | |
644 | { | |
645 | info->final_bb = e->dest; | |
646 | break; | |
647 | } | |
648 | } | |
649 | if (info->final_bb) | |
650 | FOR_EACH_EDGE (e, ei, info->switch_bb->succs) | |
651 | { | |
652 | if (e->dest == info->final_bb) | |
653 | continue; | |
654 | ||
655 | if (single_pred_p (e->dest) | |
656 | && single_succ_p (e->dest) | |
657 | && single_succ (e->dest) == info->final_bb) | |
658 | continue; | |
659 | ||
660 | info->final_bb = NULL; | |
661 | break; | |
662 | } | |
663 | ||
664 | /* Get upper and lower bounds of case values, and the covered range. */ | |
665 | min_case = gimple_switch_label (swtch, 1); | |
726a989a | 666 | max_case = gimple_switch_label (swtch, branch_num - 1); |
886cd84f SB |
667 | |
668 | info->range_min = CASE_LOW (min_case); | |
b6e99746 | 669 | if (CASE_HIGH (max_case) != NULL_TREE) |
886cd84f | 670 | info->range_max = CASE_HIGH (max_case); |
b6e99746 | 671 | else |
886cd84f SB |
672 | info->range_max = CASE_LOW (max_case); |
673 | ||
674 | info->range_size = | |
675 | int_const_binop (MINUS_EXPR, info->range_max, info->range_min); | |
b6e99746 | 676 | |
886cd84f SB |
677 | /* Get a count of the number of case labels. Single-valued case labels |
678 | simply count as one, but a case range counts double, since it may | |
679 | require two compares if it gets lowered as a branching tree. */ | |
680 | count = 0; | |
681 | for (i = 1; i < branch_num; i++) | |
682 | { | |
683 | tree elt = gimple_switch_label (swtch, i); | |
684 | count++; | |
685 | if (CASE_HIGH (elt) | |
686 | && ! tree_int_cst_equal (CASE_LOW (elt), CASE_HIGH (elt))) | |
687 | count++; | |
688 | } | |
689 | info->count = count; | |
690 | ||
691 | /* Get the number of unique non-default targets out of the GIMPLE_SWITCH | |
692 | block. Assume a CFG cleanup would have already removed degenerate | |
693 | switch statements, this allows us to just use EDGE_COUNT. */ | |
694 | info->uniq = EDGE_COUNT (gimple_bb (swtch)->succs) - 1; | |
695 | } | |
b6e99746 | 696 | |
886cd84f SB |
697 | /* Checks whether the range given by individual case statements of the SWTCH |
698 | switch statement isn't too big and whether the number of branches actually | |
699 | satisfies the size of the new array. */ | |
b6e99746 | 700 | |
886cd84f SB |
701 | static bool |
702 | check_range (struct switch_conv_info *info) | |
703 | { | |
fade902a | 704 | gcc_assert (info->range_size); |
cc269bb6 | 705 | if (!tree_fits_uhwi_p (info->range_size)) |
b6e99746 | 706 | { |
fade902a | 707 | info->reason = "index range way too large or otherwise unusable"; |
b6e99746 MJ |
708 | return false; |
709 | } | |
710 | ||
7d362f6c | 711 | if (tree_to_uhwi (info->range_size) |
886cd84f | 712 | > ((unsigned) info->count * SWITCH_CONVERSION_BRANCH_RATIO)) |
b6e99746 | 713 | { |
fade902a | 714 | info->reason = "the maximum range-branch ratio exceeded"; |
b6e99746 MJ |
715 | return false; |
716 | } | |
717 | ||
718 | return true; | |
719 | } | |
720 | ||
886cd84f | 721 | /* Checks whether all but the FINAL_BB basic blocks are empty. */ |
b6e99746 MJ |
722 | |
723 | static bool | |
886cd84f | 724 | check_all_empty_except_final (struct switch_conv_info *info) |
b6e99746 | 725 | { |
b6e99746 | 726 | edge e; |
886cd84f | 727 | edge_iterator ei; |
b6e99746 | 728 | |
886cd84f | 729 | FOR_EACH_EDGE (e, ei, info->switch_bb->succs) |
b6e99746 | 730 | { |
886cd84f SB |
731 | if (e->dest == info->final_bb) |
732 | continue; | |
b6e99746 | 733 | |
886cd84f | 734 | if (!empty_block_p (e->dest)) |
b6e99746 | 735 | { |
fade902a | 736 | info->reason = "bad case - a non-final BB not empty"; |
b6e99746 MJ |
737 | return false; |
738 | } | |
b6e99746 MJ |
739 | } |
740 | ||
741 | return true; | |
742 | } | |
743 | ||
744 | /* This function checks whether all required values in phi nodes in final_bb | |
745 | are constants. Required values are those that correspond to a basic block | |
746 | which is a part of the examined switch statement. It returns true if the | |
747 | phi nodes are OK, otherwise false. */ | |
748 | ||
749 | static bool | |
fade902a | 750 | check_final_bb (struct switch_conv_info *info) |
b6e99746 | 751 | { |
726a989a | 752 | gimple_stmt_iterator gsi; |
b6e99746 | 753 | |
fade902a SB |
754 | info->phi_count = 0; |
755 | for (gsi = gsi_start_phis (info->final_bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
b6e99746 | 756 | { |
726a989a RB |
757 | gimple phi = gsi_stmt (gsi); |
758 | unsigned int i; | |
b6e99746 | 759 | |
fade902a | 760 | info->phi_count++; |
b6e99746 | 761 | |
726a989a | 762 | for (i = 0; i < gimple_phi_num_args (phi); i++) |
b6e99746 | 763 | { |
726a989a | 764 | basic_block bb = gimple_phi_arg_edge (phi, i)->src; |
b6e99746 | 765 | |
fade902a SB |
766 | if (bb == info->switch_bb |
767 | || (single_pred_p (bb) && single_pred (bb) == info->switch_bb)) | |
b6e99746 | 768 | { |
f6e6e990 JJ |
769 | tree reloc, val; |
770 | ||
771 | val = gimple_phi_arg_def (phi, i); | |
772 | if (!is_gimple_ip_invariant (val)) | |
773 | { | |
fade902a | 774 | info->reason = "non-invariant value from a case"; |
f6e6e990 JJ |
775 | return false; /* Non-invariant argument. */ |
776 | } | |
777 | reloc = initializer_constant_valid_p (val, TREE_TYPE (val)); | |
778 | if ((flag_pic && reloc != null_pointer_node) | |
779 | || (!flag_pic && reloc == NULL_TREE)) | |
780 | { | |
781 | if (reloc) | |
fade902a SB |
782 | info->reason |
783 | = "value from a case would need runtime relocations"; | |
f6e6e990 | 784 | else |
fade902a SB |
785 | info->reason |
786 | = "value from a case is not a valid initializer"; | |
f6e6e990 JJ |
787 | return false; |
788 | } | |
b6e99746 MJ |
789 | } |
790 | } | |
791 | } | |
792 | ||
793 | return true; | |
794 | } | |
795 | ||
796 | /* The following function allocates default_values, target_{in,out}_names and | |
797 | constructors arrays. The last one is also populated with pointers to | |
798 | vectors that will become constructors of new arrays. */ | |
799 | ||
800 | static void | |
fade902a | 801 | create_temp_arrays (struct switch_conv_info *info) |
b6e99746 MJ |
802 | { |
803 | int i; | |
804 | ||
fade902a | 805 | info->default_values = XCNEWVEC (tree, info->phi_count * 3); |
9771b263 DN |
806 | /* ??? Macros do not support multi argument templates in their |
807 | argument list. We create a typedef to work around that problem. */ | |
808 | typedef vec<constructor_elt, va_gc> *vec_constructor_elt_gc; | |
809 | info->constructors = XCNEWVEC (vec_constructor_elt_gc, info->phi_count); | |
fade902a SB |
810 | info->target_inbound_names = info->default_values + info->phi_count; |
811 | info->target_outbound_names = info->target_inbound_names + info->phi_count; | |
812 | for (i = 0; i < info->phi_count; i++) | |
ae7e9ddd | 813 | vec_alloc (info->constructors[i], tree_to_uhwi (info->range_size) + 1); |
b6e99746 MJ |
814 | } |
815 | ||
816 | /* Free the arrays created by create_temp_arrays(). The vectors that are | |
817 | created by that function are not freed here, however, because they have | |
818 | already become constructors and must be preserved. */ | |
819 | ||
820 | static void | |
fade902a | 821 | free_temp_arrays (struct switch_conv_info *info) |
b6e99746 | 822 | { |
fade902a SB |
823 | XDELETEVEC (info->constructors); |
824 | XDELETEVEC (info->default_values); | |
b6e99746 MJ |
825 | } |
826 | ||
827 | /* Populate the array of default values in the order of phi nodes. | |
828 | DEFAULT_CASE is the CASE_LABEL_EXPR for the default switch branch. */ | |
829 | ||
830 | static void | |
fade902a | 831 | gather_default_values (tree default_case, struct switch_conv_info *info) |
b6e99746 | 832 | { |
726a989a | 833 | gimple_stmt_iterator gsi; |
b6e99746 MJ |
834 | basic_block bb = label_to_block (CASE_LABEL (default_case)); |
835 | edge e; | |
726a989a | 836 | int i = 0; |
b6e99746 MJ |
837 | |
838 | gcc_assert (CASE_LOW (default_case) == NULL_TREE); | |
839 | ||
fade902a SB |
840 | if (bb == info->final_bb) |
841 | e = find_edge (info->switch_bb, bb); | |
b6e99746 MJ |
842 | else |
843 | e = single_succ_edge (bb); | |
844 | ||
fade902a | 845 | for (gsi = gsi_start_phis (info->final_bb); !gsi_end_p (gsi); gsi_next (&gsi)) |
b6e99746 | 846 | { |
726a989a | 847 | gimple phi = gsi_stmt (gsi); |
b6e99746 MJ |
848 | tree val = PHI_ARG_DEF_FROM_EDGE (phi, e); |
849 | gcc_assert (val); | |
fade902a | 850 | info->default_values[i++] = val; |
b6e99746 MJ |
851 | } |
852 | } | |
853 | ||
854 | /* The following function populates the vectors in the constructors array with | |
855 | future contents of the static arrays. The vectors are populated in the | |
856 | order of phi nodes. SWTCH is the switch statement being converted. */ | |
857 | ||
858 | static void | |
fade902a | 859 | build_constructors (gimple swtch, struct switch_conv_info *info) |
b6e99746 | 860 | { |
726a989a | 861 | unsigned i, branch_num = gimple_switch_num_labels (swtch); |
fade902a | 862 | tree pos = info->range_min; |
b6e99746 | 863 | |
726a989a | 864 | for (i = 1; i < branch_num; i++) |
b6e99746 | 865 | { |
726a989a | 866 | tree cs = gimple_switch_label (swtch, i); |
b6e99746 MJ |
867 | basic_block bb = label_to_block (CASE_LABEL (cs)); |
868 | edge e; | |
726a989a RB |
869 | tree high; |
870 | gimple_stmt_iterator gsi; | |
b6e99746 MJ |
871 | int j; |
872 | ||
fade902a SB |
873 | if (bb == info->final_bb) |
874 | e = find_edge (info->switch_bb, bb); | |
b6e99746 MJ |
875 | else |
876 | e = single_succ_edge (bb); | |
877 | gcc_assert (e); | |
878 | ||
879 | while (tree_int_cst_lt (pos, CASE_LOW (cs))) | |
880 | { | |
881 | int k; | |
fade902a | 882 | for (k = 0; k < info->phi_count; k++) |
b6e99746 | 883 | { |
f32682ca | 884 | constructor_elt elt; |
b6e99746 | 885 | |
f32682ca | 886 | elt.index = int_const_binop (MINUS_EXPR, pos, info->range_min); |
d1f98542 RB |
887 | elt.value |
888 | = unshare_expr_without_location (info->default_values[k]); | |
9771b263 | 889 | info->constructors[k]->quick_push (elt); |
b6e99746 MJ |
890 | } |
891 | ||
d35936ab | 892 | pos = int_const_binop (PLUS_EXPR, pos, integer_one_node); |
b6e99746 | 893 | } |
b1ae1681 | 894 | gcc_assert (tree_int_cst_equal (pos, CASE_LOW (cs))); |
b6e99746 MJ |
895 | |
896 | j = 0; | |
897 | if (CASE_HIGH (cs)) | |
898 | high = CASE_HIGH (cs); | |
899 | else | |
b1ae1681 | 900 | high = CASE_LOW (cs); |
fade902a | 901 | for (gsi = gsi_start_phis (info->final_bb); |
726a989a | 902 | !gsi_end_p (gsi); gsi_next (&gsi)) |
b6e99746 | 903 | { |
726a989a | 904 | gimple phi = gsi_stmt (gsi); |
b6e99746 | 905 | tree val = PHI_ARG_DEF_FROM_EDGE (phi, e); |
7f2a9982 | 906 | tree low = CASE_LOW (cs); |
b6e99746 MJ |
907 | pos = CASE_LOW (cs); |
908 | ||
b8698a0f | 909 | do |
b6e99746 | 910 | { |
f32682ca | 911 | constructor_elt elt; |
b6e99746 | 912 | |
f32682ca | 913 | elt.index = int_const_binop (MINUS_EXPR, pos, info->range_min); |
d1f98542 | 914 | elt.value = unshare_expr_without_location (val); |
9771b263 | 915 | info->constructors[j]->quick_push (elt); |
b6e99746 | 916 | |
d35936ab | 917 | pos = int_const_binop (PLUS_EXPR, pos, integer_one_node); |
7156c8ab MJ |
918 | } while (!tree_int_cst_lt (high, pos) |
919 | && tree_int_cst_lt (low, pos)); | |
b6e99746 MJ |
920 | j++; |
921 | } | |
922 | } | |
923 | } | |
924 | ||
7156c8ab MJ |
925 | /* If all values in the constructor vector are the same, return the value. |
926 | Otherwise return NULL_TREE. Not supposed to be called for empty | |
927 | vectors. */ | |
928 | ||
929 | static tree | |
9771b263 | 930 | constructor_contains_same_values_p (vec<constructor_elt, va_gc> *vec) |
7156c8ab | 931 | { |
8e97bc2b | 932 | unsigned int i; |
7156c8ab | 933 | tree prev = NULL_TREE; |
8e97bc2b | 934 | constructor_elt *elt; |
7156c8ab | 935 | |
9771b263 | 936 | FOR_EACH_VEC_SAFE_ELT (vec, i, elt) |
7156c8ab | 937 | { |
7156c8ab MJ |
938 | if (!prev) |
939 | prev = elt->value; | |
940 | else if (!operand_equal_p (elt->value, prev, OEP_ONLY_CONST)) | |
941 | return NULL_TREE; | |
942 | } | |
943 | return prev; | |
944 | } | |
945 | ||
8e97bc2b JJ |
946 | /* Return type which should be used for array elements, either TYPE, |
947 | or for integral type some smaller integral type that can still hold | |
948 | all the constants. */ | |
949 | ||
950 | static tree | |
fade902a SB |
951 | array_value_type (gimple swtch, tree type, int num, |
952 | struct switch_conv_info *info) | |
8e97bc2b | 953 | { |
9771b263 | 954 | unsigned int i, len = vec_safe_length (info->constructors[num]); |
8e97bc2b JJ |
955 | constructor_elt *elt; |
956 | enum machine_mode mode; | |
957 | int sign = 0; | |
958 | tree smaller_type; | |
959 | ||
960 | if (!INTEGRAL_TYPE_P (type)) | |
961 | return type; | |
962 | ||
963 | mode = GET_CLASS_NARROWEST_MODE (GET_MODE_CLASS (TYPE_MODE (type))); | |
964 | if (GET_MODE_SIZE (TYPE_MODE (type)) <= GET_MODE_SIZE (mode)) | |
965 | return type; | |
966 | ||
967 | if (len < (optimize_bb_for_size_p (gimple_bb (swtch)) ? 2 : 32)) | |
968 | return type; | |
969 | ||
9771b263 | 970 | FOR_EACH_VEC_SAFE_ELT (info->constructors[num], i, elt) |
8e97bc2b JJ |
971 | { |
972 | double_int cst; | |
973 | ||
974 | if (TREE_CODE (elt->value) != INTEGER_CST) | |
975 | return type; | |
976 | ||
977 | cst = TREE_INT_CST (elt->value); | |
978 | while (1) | |
979 | { | |
980 | unsigned int prec = GET_MODE_BITSIZE (mode); | |
981 | if (prec > HOST_BITS_PER_WIDE_INT) | |
982 | return type; | |
983 | ||
27bcd47c | 984 | if (sign >= 0 && cst == cst.zext (prec)) |
8e97bc2b | 985 | { |
27bcd47c | 986 | if (sign == 0 && cst == cst.sext (prec)) |
8e97bc2b JJ |
987 | break; |
988 | sign = 1; | |
989 | break; | |
990 | } | |
27bcd47c | 991 | if (sign <= 0 && cst == cst.sext (prec)) |
8e97bc2b JJ |
992 | { |
993 | sign = -1; | |
994 | break; | |
995 | } | |
996 | ||
997 | if (sign == 1) | |
998 | sign = 0; | |
999 | ||
1000 | mode = GET_MODE_WIDER_MODE (mode); | |
1001 | if (mode == VOIDmode | |
1002 | || GET_MODE_SIZE (mode) >= GET_MODE_SIZE (TYPE_MODE (type))) | |
1003 | return type; | |
1004 | } | |
1005 | } | |
1006 | ||
1007 | if (sign == 0) | |
1008 | sign = TYPE_UNSIGNED (type) ? 1 : -1; | |
1009 | smaller_type = lang_hooks.types.type_for_mode (mode, sign >= 0); | |
1010 | if (GET_MODE_SIZE (TYPE_MODE (type)) | |
1011 | <= GET_MODE_SIZE (TYPE_MODE (smaller_type))) | |
1012 | return type; | |
1013 | ||
1014 | return smaller_type; | |
1015 | } | |
1016 | ||
b6e99746 MJ |
1017 | /* Create an appropriate array type and declaration and assemble a static array |
1018 | variable. Also create a load statement that initializes the variable in | |
1019 | question with a value from the static array. SWTCH is the switch statement | |
1020 | being converted, NUM is the index to arrays of constructors, default values | |
1021 | and target SSA names for this particular array. ARR_INDEX_TYPE is the type | |
1022 | of the index of the new array, PHI is the phi node of the final BB that | |
1023 | corresponds to the value that will be loaded from the created array. TIDX | |
7156c8ab MJ |
1024 | is an ssa name of a temporary variable holding the index for loads from the |
1025 | new array. */ | |
b6e99746 MJ |
1026 | |
1027 | static void | |
726a989a | 1028 | build_one_array (gimple swtch, int num, tree arr_index_type, gimple phi, |
fade902a | 1029 | tree tidx, struct switch_conv_info *info) |
b6e99746 | 1030 | { |
7156c8ab | 1031 | tree name, cst; |
726a989a | 1032 | gimple load; |
7156c8ab | 1033 | gimple_stmt_iterator gsi = gsi_for_stmt (swtch); |
c2255bc4 | 1034 | location_t loc = gimple_location (swtch); |
b6e99746 | 1035 | |
fade902a | 1036 | gcc_assert (info->default_values[num]); |
b6e99746 | 1037 | |
070ecdfd | 1038 | name = copy_ssa_name (PHI_RESULT (phi), NULL); |
fade902a | 1039 | info->target_inbound_names[num] = name; |
b6e99746 | 1040 | |
fade902a | 1041 | cst = constructor_contains_same_values_p (info->constructors[num]); |
7156c8ab MJ |
1042 | if (cst) |
1043 | load = gimple_build_assign (name, cst); | |
1044 | else | |
1045 | { | |
8e97bc2b | 1046 | tree array_type, ctor, decl, value_type, fetch, default_type; |
7156c8ab | 1047 | |
fade902a SB |
1048 | default_type = TREE_TYPE (info->default_values[num]); |
1049 | value_type = array_value_type (swtch, default_type, num, info); | |
7156c8ab | 1050 | array_type = build_array_type (value_type, arr_index_type); |
8e97bc2b JJ |
1051 | if (default_type != value_type) |
1052 | { | |
1053 | unsigned int i; | |
1054 | constructor_elt *elt; | |
1055 | ||
9771b263 | 1056 | FOR_EACH_VEC_SAFE_ELT (info->constructors[num], i, elt) |
8e97bc2b JJ |
1057 | elt->value = fold_convert (value_type, elt->value); |
1058 | } | |
fade902a | 1059 | ctor = build_constructor (array_type, info->constructors[num]); |
7156c8ab | 1060 | TREE_CONSTANT (ctor) = true; |
5f7ae6b6 | 1061 | TREE_STATIC (ctor) = true; |
7156c8ab | 1062 | |
c2255bc4 | 1063 | decl = build_decl (loc, VAR_DECL, NULL_TREE, array_type); |
7156c8ab MJ |
1064 | TREE_STATIC (decl) = 1; |
1065 | DECL_INITIAL (decl) = ctor; | |
1066 | ||
1067 | DECL_NAME (decl) = create_tmp_var_name ("CSWTCH"); | |
1068 | DECL_ARTIFICIAL (decl) = 1; | |
1069 | TREE_CONSTANT (decl) = 1; | |
2e3b4885 | 1070 | TREE_READONLY (decl) = 1; |
7156c8ab MJ |
1071 | varpool_finalize_decl (decl); |
1072 | ||
1073 | fetch = build4 (ARRAY_REF, value_type, decl, tidx, NULL_TREE, | |
1074 | NULL_TREE); | |
8e97bc2b JJ |
1075 | if (default_type != value_type) |
1076 | { | |
1077 | fetch = fold_convert (default_type, fetch); | |
1078 | fetch = force_gimple_operand_gsi (&gsi, fetch, true, NULL_TREE, | |
1079 | true, GSI_SAME_STMT); | |
1080 | } | |
7156c8ab MJ |
1081 | load = gimple_build_assign (name, fetch); |
1082 | } | |
b6e99746 | 1083 | |
726a989a | 1084 | gsi_insert_before (&gsi, load, GSI_SAME_STMT); |
7156c8ab | 1085 | update_stmt (load); |
fade902a | 1086 | info->arr_ref_last = load; |
b6e99746 MJ |
1087 | } |
1088 | ||
1089 | /* Builds and initializes static arrays initialized with values gathered from | |
1090 | the SWTCH switch statement. Also creates statements that load values from | |
1091 | them. */ | |
1092 | ||
1093 | static void | |
fade902a | 1094 | build_arrays (gimple swtch, struct switch_conv_info *info) |
b6e99746 MJ |
1095 | { |
1096 | tree arr_index_type; | |
83d5977e | 1097 | tree tidx, sub, utype; |
726a989a RB |
1098 | gimple stmt; |
1099 | gimple_stmt_iterator gsi; | |
b6e99746 | 1100 | int i; |
db3927fb | 1101 | location_t loc = gimple_location (swtch); |
b6e99746 | 1102 | |
726a989a | 1103 | gsi = gsi_for_stmt (swtch); |
04e78aa9 | 1104 | |
edb9b69e | 1105 | /* Make sure we do not generate arithmetics in a subrange. */ |
fade902a | 1106 | utype = TREE_TYPE (info->index_expr); |
edb9b69e JJ |
1107 | if (TREE_TYPE (utype)) |
1108 | utype = lang_hooks.types.type_for_mode (TYPE_MODE (TREE_TYPE (utype)), 1); | |
1109 | else | |
1110 | utype = lang_hooks.types.type_for_mode (TYPE_MODE (utype), 1); | |
1111 | ||
fade902a | 1112 | arr_index_type = build_index_type (info->range_size); |
83d5977e | 1113 | tidx = make_ssa_name (utype, NULL); |
edb9b69e | 1114 | sub = fold_build2_loc (loc, MINUS_EXPR, utype, |
fade902a SB |
1115 | fold_convert_loc (loc, utype, info->index_expr), |
1116 | fold_convert_loc (loc, utype, info->range_min)); | |
fae1034e | 1117 | sub = force_gimple_operand_gsi (&gsi, sub, |
726a989a RB |
1118 | false, NULL, true, GSI_SAME_STMT); |
1119 | stmt = gimple_build_assign (tidx, sub); | |
b6e99746 | 1120 | |
726a989a | 1121 | gsi_insert_before (&gsi, stmt, GSI_SAME_STMT); |
7156c8ab | 1122 | update_stmt (stmt); |
fade902a | 1123 | info->arr_ref_first = stmt; |
b6e99746 | 1124 | |
fade902a | 1125 | for (gsi = gsi_start_phis (info->final_bb), i = 0; |
726a989a | 1126 | !gsi_end_p (gsi); gsi_next (&gsi), i++) |
fade902a | 1127 | build_one_array (swtch, i, arr_index_type, gsi_stmt (gsi), tidx, info); |
b6e99746 MJ |
1128 | } |
1129 | ||
1130 | /* Generates and appropriately inserts loads of default values at the position | |
1131 | given by BSI. Returns the last inserted statement. */ | |
1132 | ||
726a989a | 1133 | static gimple |
fade902a | 1134 | gen_def_assigns (gimple_stmt_iterator *gsi, struct switch_conv_info *info) |
b6e99746 MJ |
1135 | { |
1136 | int i; | |
726a989a | 1137 | gimple assign = NULL; |
b6e99746 | 1138 | |
fade902a | 1139 | for (i = 0; i < info->phi_count; i++) |
b6e99746 | 1140 | { |
070ecdfd | 1141 | tree name = copy_ssa_name (info->target_inbound_names[i], NULL); |
fade902a SB |
1142 | info->target_outbound_names[i] = name; |
1143 | assign = gimple_build_assign (name, info->default_values[i]); | |
726a989a | 1144 | gsi_insert_before (gsi, assign, GSI_SAME_STMT); |
7156c8ab | 1145 | update_stmt (assign); |
b6e99746 MJ |
1146 | } |
1147 | return assign; | |
1148 | } | |
1149 | ||
1150 | /* Deletes the unused bbs and edges that now contain the switch statement and | |
1151 | its empty branch bbs. BBD is the now dead BB containing the original switch | |
1152 | statement, FINAL is the last BB of the converted switch statement (in terms | |
1153 | of succession). */ | |
1154 | ||
1155 | static void | |
1156 | prune_bbs (basic_block bbd, basic_block final) | |
1157 | { | |
1158 | edge_iterator ei; | |
1159 | edge e; | |
1160 | ||
1161 | for (ei = ei_start (bbd->succs); (e = ei_safe_edge (ei)); ) | |
1162 | { | |
1163 | basic_block bb; | |
1164 | bb = e->dest; | |
1165 | remove_edge (e); | |
1166 | if (bb != final) | |
1167 | delete_basic_block (bb); | |
1168 | } | |
1169 | delete_basic_block (bbd); | |
1170 | } | |
1171 | ||
1172 | /* Add values to phi nodes in final_bb for the two new edges. E1F is the edge | |
1173 | from the basic block loading values from an array and E2F from the basic | |
1174 | block loading default values. BBF is the last switch basic block (see the | |
1175 | bbf description in the comment below). */ | |
1176 | ||
1177 | static void | |
fade902a SB |
1178 | fix_phi_nodes (edge e1f, edge e2f, basic_block bbf, |
1179 | struct switch_conv_info *info) | |
b6e99746 | 1180 | { |
726a989a | 1181 | gimple_stmt_iterator gsi; |
b6e99746 MJ |
1182 | int i; |
1183 | ||
726a989a RB |
1184 | for (gsi = gsi_start_phis (bbf), i = 0; |
1185 | !gsi_end_p (gsi); gsi_next (&gsi), i++) | |
b6e99746 | 1186 | { |
726a989a | 1187 | gimple phi = gsi_stmt (gsi); |
9e227d60 DC |
1188 | add_phi_arg (phi, info->target_inbound_names[i], e1f, UNKNOWN_LOCATION); |
1189 | add_phi_arg (phi, info->target_outbound_names[i], e2f, UNKNOWN_LOCATION); | |
b6e99746 | 1190 | } |
b6e99746 MJ |
1191 | } |
1192 | ||
1193 | /* Creates a check whether the switch expression value actually falls into the | |
1194 | range given by all the cases. If it does not, the temporaries are loaded | |
1195 | with default values instead. SWTCH is the switch statement being converted. | |
1196 | ||
1197 | bb0 is the bb with the switch statement, however, we'll end it with a | |
1198 | condition instead. | |
1199 | ||
1200 | bb1 is the bb to be used when the range check went ok. It is derived from | |
1201 | the switch BB | |
1202 | ||
1203 | bb2 is the bb taken when the expression evaluated outside of the range | |
1204 | covered by the created arrays. It is populated by loads of default | |
1205 | values. | |
1206 | ||
1207 | bbF is a fall through for both bb1 and bb2 and contains exactly what | |
1208 | originally followed the switch statement. | |
1209 | ||
1210 | bbD contains the switch statement (in the end). It is unreachable but we | |
1211 | still need to strip off its edges. | |
1212 | */ | |
1213 | ||
1214 | static void | |
fade902a | 1215 | gen_inbound_check (gimple swtch, struct switch_conv_info *info) |
b6e99746 | 1216 | { |
c2255bc4 AH |
1217 | tree label_decl1 = create_artificial_label (UNKNOWN_LOCATION); |
1218 | tree label_decl2 = create_artificial_label (UNKNOWN_LOCATION); | |
1219 | tree label_decl3 = create_artificial_label (UNKNOWN_LOCATION); | |
726a989a | 1220 | gimple label1, label2, label3; |
edb9b69e | 1221 | tree utype, tidx; |
b6e99746 MJ |
1222 | tree bound; |
1223 | ||
726a989a | 1224 | gimple cond_stmt; |
b6e99746 | 1225 | |
726a989a RB |
1226 | gimple last_assign; |
1227 | gimple_stmt_iterator gsi; | |
b6e99746 MJ |
1228 | basic_block bb0, bb1, bb2, bbf, bbd; |
1229 | edge e01, e02, e21, e1d, e1f, e2f; | |
db3927fb | 1230 | location_t loc = gimple_location (swtch); |
b6e99746 | 1231 | |
fade902a | 1232 | gcc_assert (info->default_values); |
6ab1ab14 | 1233 | |
726a989a | 1234 | bb0 = gimple_bb (swtch); |
b6e99746 | 1235 | |
fade902a | 1236 | tidx = gimple_assign_lhs (info->arr_ref_first); |
edb9b69e | 1237 | utype = TREE_TYPE (tidx); |
145544ab | 1238 | |
b6e99746 | 1239 | /* (end of) block 0 */ |
fade902a | 1240 | gsi = gsi_for_stmt (info->arr_ref_first); |
edb9b69e | 1241 | gsi_next (&gsi); |
b6e99746 | 1242 | |
fade902a | 1243 | bound = fold_convert_loc (loc, utype, info->range_size); |
edb9b69e | 1244 | cond_stmt = gimple_build_cond (LE_EXPR, tidx, bound, NULL_TREE, NULL_TREE); |
726a989a | 1245 | gsi_insert_before (&gsi, cond_stmt, GSI_SAME_STMT); |
7156c8ab | 1246 | update_stmt (cond_stmt); |
b6e99746 MJ |
1247 | |
1248 | /* block 2 */ | |
726a989a RB |
1249 | label2 = gimple_build_label (label_decl2); |
1250 | gsi_insert_before (&gsi, label2, GSI_SAME_STMT); | |
fade902a | 1251 | last_assign = gen_def_assigns (&gsi, info); |
b6e99746 MJ |
1252 | |
1253 | /* block 1 */ | |
726a989a RB |
1254 | label1 = gimple_build_label (label_decl1); |
1255 | gsi_insert_before (&gsi, label1, GSI_SAME_STMT); | |
b6e99746 MJ |
1256 | |
1257 | /* block F */ | |
fade902a | 1258 | gsi = gsi_start_bb (info->final_bb); |
726a989a RB |
1259 | label3 = gimple_build_label (label_decl3); |
1260 | gsi_insert_before (&gsi, label3, GSI_SAME_STMT); | |
b6e99746 MJ |
1261 | |
1262 | /* cfg fix */ | |
726a989a | 1263 | e02 = split_block (bb0, cond_stmt); |
b6e99746 MJ |
1264 | bb2 = e02->dest; |
1265 | ||
1266 | e21 = split_block (bb2, last_assign); | |
1267 | bb1 = e21->dest; | |
1268 | remove_edge (e21); | |
1269 | ||
fade902a | 1270 | e1d = split_block (bb1, info->arr_ref_last); |
b6e99746 MJ |
1271 | bbd = e1d->dest; |
1272 | remove_edge (e1d); | |
1273 | ||
1274 | /* flags and profiles of the edge for in-range values */ | |
1275 | e01 = make_edge (bb0, bb1, EDGE_TRUE_VALUE); | |
fade902a SB |
1276 | e01->probability = REG_BR_PROB_BASE - info->default_prob; |
1277 | e01->count = info->other_count; | |
b6e99746 MJ |
1278 | |
1279 | /* flags and profiles of the edge taking care of out-of-range values */ | |
1280 | e02->flags &= ~EDGE_FALLTHRU; | |
1281 | e02->flags |= EDGE_FALSE_VALUE; | |
fade902a SB |
1282 | e02->probability = info->default_prob; |
1283 | e02->count = info->default_count; | |
b6e99746 | 1284 | |
fade902a | 1285 | bbf = info->final_bb; |
b6e99746 MJ |
1286 | |
1287 | e1f = make_edge (bb1, bbf, EDGE_FALLTHRU); | |
1288 | e1f->probability = REG_BR_PROB_BASE; | |
fade902a | 1289 | e1f->count = info->other_count; |
b6e99746 MJ |
1290 | |
1291 | e2f = make_edge (bb2, bbf, EDGE_FALLTHRU); | |
1292 | e2f->probability = REG_BR_PROB_BASE; | |
fade902a | 1293 | e2f->count = info->default_count; |
b6e99746 MJ |
1294 | |
1295 | /* frequencies of the new BBs */ | |
1296 | bb1->frequency = EDGE_FREQUENCY (e01); | |
1297 | bb2->frequency = EDGE_FREQUENCY (e02); | |
1298 | bbf->frequency = EDGE_FREQUENCY (e1f) + EDGE_FREQUENCY (e2f); | |
1299 | ||
6ab1ab14 SB |
1300 | /* Tidy blocks that have become unreachable. */ |
1301 | prune_bbs (bbd, info->final_bb); | |
b6e99746 | 1302 | |
6ab1ab14 | 1303 | /* Fixup the PHI nodes in bbF. */ |
fade902a | 1304 | fix_phi_nodes (e1f, e2f, bbf, info); |
b6e99746 | 1305 | |
6ab1ab14 SB |
1306 | /* Fix the dominator tree, if it is available. */ |
1307 | if (dom_info_available_p (CDI_DOMINATORS)) | |
1308 | { | |
9771b263 | 1309 | vec<basic_block> bbs_to_fix_dom; |
6ab1ab14 SB |
1310 | |
1311 | set_immediate_dominator (CDI_DOMINATORS, bb1, bb0); | |
1312 | set_immediate_dominator (CDI_DOMINATORS, bb2, bb0); | |
531b10fc | 1313 | if (! get_immediate_dominator (CDI_DOMINATORS, bbf)) |
6ab1ab14 SB |
1314 | /* If bbD was the immediate dominator ... */ |
1315 | set_immediate_dominator (CDI_DOMINATORS, bbf, bb0); | |
1316 | ||
9771b263 DN |
1317 | bbs_to_fix_dom.create (4); |
1318 | bbs_to_fix_dom.quick_push (bb0); | |
1319 | bbs_to_fix_dom.quick_push (bb1); | |
1320 | bbs_to_fix_dom.quick_push (bb2); | |
1321 | bbs_to_fix_dom.quick_push (bbf); | |
6ab1ab14 SB |
1322 | |
1323 | iterate_fix_dominators (CDI_DOMINATORS, bbs_to_fix_dom, true); | |
9771b263 | 1324 | bbs_to_fix_dom.release (); |
6ab1ab14 | 1325 | } |
b6e99746 MJ |
1326 | } |
1327 | ||
1328 | /* The following function is invoked on every switch statement (the current one | |
1329 | is given in SWTCH) and runs the individual phases of switch conversion on it | |
fade902a SB |
1330 | one after another until one fails or the conversion is completed. |
1331 | Returns NULL on success, or a pointer to a string with the reason why the | |
1332 | conversion failed. */ | |
b6e99746 | 1333 | |
fade902a | 1334 | static const char * |
726a989a | 1335 | process_switch (gimple swtch) |
b6e99746 | 1336 | { |
fade902a | 1337 | struct switch_conv_info info; |
b6e99746 | 1338 | |
238065a7 SB |
1339 | /* Group case labels so that we get the right results from the heuristics |
1340 | that decide on the code generation approach for this switch. */ | |
1341 | group_case_labels_stmt (swtch); | |
1342 | ||
1343 | /* If this switch is now a degenerate case with only a default label, | |
1344 | there is nothing left for us to do. */ | |
1345 | if (gimple_switch_num_labels (swtch) < 2) | |
1346 | return "switch is a degenerate case"; | |
886cd84f SB |
1347 | |
1348 | collect_switch_conv_info (swtch, &info); | |
1349 | ||
1350 | /* No error markers should reach here (they should be filtered out | |
1351 | during gimplification). */ | |
1352 | gcc_checking_assert (TREE_TYPE (info.index_expr) != error_mark_node); | |
1353 | ||
531b10fc SB |
1354 | /* A switch on a constant should have been optimized in tree-cfg-cleanup. */ |
1355 | gcc_checking_assert (! TREE_CONSTANT (info.index_expr)); | |
886cd84f | 1356 | |
531b10fc | 1357 | if (info.uniq <= MAX_CASE_BIT_TESTS) |
886cd84f | 1358 | { |
531b10fc | 1359 | if (expand_switch_using_bit_tests_p (info.range_size, |
886cd84f | 1360 | info.uniq, info.count)) |
531b10fc SB |
1361 | { |
1362 | if (dump_file) | |
1363 | fputs (" expanding as bit test is preferable\n", dump_file); | |
1364 | emit_case_bit_tests (swtch, info.index_expr, | |
1365 | info.range_min, info.range_size); | |
a9e0d843 RB |
1366 | if (current_loops) |
1367 | loops_state_set (LOOPS_NEED_FIXUP); | |
531b10fc SB |
1368 | return NULL; |
1369 | } | |
1370 | ||
1371 | if (info.uniq <= 2) | |
1372 | /* This will be expanded as a decision tree in stmt.c:expand_case. */ | |
1373 | return " expanding as jumps is preferable"; | |
886cd84f | 1374 | } |
b6e99746 | 1375 | |
531b10fc SB |
1376 | /* If there is no common successor, we cannot do the transformation. */ |
1377 | if (! info.final_bb) | |
1378 | return "no common successor to all case label target blocks found"; | |
1379 | ||
b6e99746 | 1380 | /* Check the case label values are within reasonable range: */ |
886cd84f | 1381 | if (!check_range (&info)) |
fade902a SB |
1382 | { |
1383 | gcc_assert (info.reason); | |
1384 | return info.reason; | |
1385 | } | |
b6e99746 MJ |
1386 | |
1387 | /* For all the cases, see whether they are empty, the assignments they | |
1388 | represent constant and so on... */ | |
886cd84f | 1389 | if (! check_all_empty_except_final (&info)) |
8e97bc2b | 1390 | { |
886cd84f SB |
1391 | gcc_assert (info.reason); |
1392 | return info.reason; | |
8e97bc2b | 1393 | } |
fade902a SB |
1394 | if (!check_final_bb (&info)) |
1395 | { | |
1396 | gcc_assert (info.reason); | |
1397 | return info.reason; | |
1398 | } | |
b6e99746 MJ |
1399 | |
1400 | /* At this point all checks have passed and we can proceed with the | |
1401 | transformation. */ | |
1402 | ||
fade902a | 1403 | create_temp_arrays (&info); |
fd8d363e | 1404 | gather_default_values (gimple_switch_default_label (swtch), &info); |
fade902a | 1405 | build_constructors (swtch, &info); |
b6e99746 | 1406 | |
fade902a SB |
1407 | build_arrays (swtch, &info); /* Build the static arrays and assignments. */ |
1408 | gen_inbound_check (swtch, &info); /* Build the bounds check. */ | |
b6e99746 MJ |
1409 | |
1410 | /* Cleanup: */ | |
fade902a SB |
1411 | free_temp_arrays (&info); |
1412 | return NULL; | |
b6e99746 MJ |
1413 | } |
1414 | ||
1415 | /* The main function of the pass scans statements for switches and invokes | |
1416 | process_switch on them. */ | |
1417 | ||
1418 | static unsigned int | |
1419 | do_switchconv (void) | |
1420 | { | |
1421 | basic_block bb; | |
1422 | ||
1423 | FOR_EACH_BB (bb) | |
1424 | { | |
fade902a | 1425 | const char *failure_reason; |
726a989a RB |
1426 | gimple stmt = last_stmt (bb); |
1427 | if (stmt && gimple_code (stmt) == GIMPLE_SWITCH) | |
b6e99746 | 1428 | { |
b6e99746 MJ |
1429 | if (dump_file) |
1430 | { | |
726a989a RB |
1431 | expanded_location loc = expand_location (gimple_location (stmt)); |
1432 | ||
b6e99746 MJ |
1433 | fprintf (dump_file, "beginning to process the following " |
1434 | "SWITCH statement (%s:%d) : ------- \n", | |
1435 | loc.file, loc.line); | |
726a989a | 1436 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); |
edb30094 | 1437 | putc ('\n', dump_file); |
b6e99746 MJ |
1438 | } |
1439 | ||
fade902a SB |
1440 | failure_reason = process_switch (stmt); |
1441 | if (! failure_reason) | |
b6e99746 MJ |
1442 | { |
1443 | if (dump_file) | |
1444 | { | |
edb30094 UB |
1445 | fputs ("Switch converted\n", dump_file); |
1446 | fputs ("--------------------------------\n", dump_file); | |
b6e99746 | 1447 | } |
531b10fc SB |
1448 | |
1449 | /* Make no effort to update the post-dominator tree. It is actually not | |
1450 | that hard for the transformations we have performed, but it is not | |
1451 | supported by iterate_fix_dominators. */ | |
1452 | free_dominance_info (CDI_POST_DOMINATORS); | |
b6e99746 MJ |
1453 | } |
1454 | else | |
1455 | { | |
1456 | if (dump_file) | |
1457 | { | |
edb30094 | 1458 | fputs ("Bailing out - ", dump_file); |
fade902a SB |
1459 | fputs (failure_reason, dump_file); |
1460 | fputs ("\n--------------------------------\n", dump_file); | |
b6e99746 MJ |
1461 | } |
1462 | } | |
1463 | } | |
1464 | } | |
1465 | ||
1466 | return 0; | |
1467 | } | |
1468 | ||
1469 | /* The pass gate. */ | |
1470 | ||
1471 | static bool | |
1472 | switchconv_gate (void) | |
1473 | { | |
1474 | return flag_tree_switch_conversion != 0; | |
1475 | } | |
1476 | ||
27a4cd48 DM |
1477 | namespace { |
1478 | ||
1479 | const pass_data pass_data_convert_switch = | |
b6e99746 | 1480 | { |
27a4cd48 DM |
1481 | GIMPLE_PASS, /* type */ |
1482 | "switchconv", /* name */ | |
1483 | OPTGROUP_NONE, /* optinfo_flags */ | |
1484 | true, /* has_gate */ | |
1485 | true, /* has_execute */ | |
1486 | TV_TREE_SWITCH_CONVERSION, /* tv_id */ | |
1487 | ( PROP_cfg | PROP_ssa ), /* properties_required */ | |
1488 | 0, /* properties_provided */ | |
1489 | 0, /* properties_destroyed */ | |
1490 | 0, /* todo_flags_start */ | |
1491 | ( TODO_update_ssa | TODO_verify_ssa | |
1492 | | TODO_verify_stmts | |
1493 | | TODO_verify_flow ), /* todo_flags_finish */ | |
b6e99746 | 1494 | }; |
27a4cd48 DM |
1495 | |
1496 | class pass_convert_switch : public gimple_opt_pass | |
1497 | { | |
1498 | public: | |
c3284718 RS |
1499 | pass_convert_switch (gcc::context *ctxt) |
1500 | : gimple_opt_pass (pass_data_convert_switch, ctxt) | |
27a4cd48 DM |
1501 | {} |
1502 | ||
1503 | /* opt_pass methods: */ | |
1504 | bool gate () { return switchconv_gate (); } | |
1505 | unsigned int execute () { return do_switchconv (); } | |
1506 | ||
1507 | }; // class pass_convert_switch | |
1508 | ||
1509 | } // anon namespace | |
1510 | ||
1511 | gimple_opt_pass * | |
1512 | make_pass_convert_switch (gcc::context *ctxt) | |
1513 | { | |
1514 | return new pass_convert_switch (ctxt); | |
1515 | } |