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bccafa26 | 1 | /* Expands front end tree to back end RTL for GCC |
3aea1f79 | 2 | Copyright (C) 1987-2014 Free Software Foundation, Inc. |
9dfbe515 | 3 | |
f12b58b3 | 4 | This file is part of GCC. |
9dfbe515 | 5 | |
f12b58b3 | 6 | GCC is free software; you can redistribute it and/or modify it under |
7 | the terms of the GNU General Public License as published by the Free | |
8c4c00c1 | 8 | Software Foundation; either version 3, or (at your option) any later |
f12b58b3 | 9 | version. |
9dfbe515 | 10 | |
f12b58b3 | 11 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
12 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
13 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
14 | for more details. | |
9dfbe515 | 15 | |
16 | You should have received a copy of the GNU General Public License | |
8c4c00c1 | 17 | along with GCC; see the file COPYING3. If not see |
18 | <http://www.gnu.org/licenses/>. */ | |
9dfbe515 | 19 | |
9dfbe515 | 20 | /* This file handles the generation of rtl code from tree structure |
21 | above the level of expressions, using subroutines in exp*.c and emit-rtl.c. | |
9dfbe515 | 22 | The functions whose names start with `expand_' are called by the |
fcb807f8 | 23 | expander to generate RTL instructions for various kinds of constructs. */ |
9dfbe515 | 24 | |
25 | #include "config.h" | |
405711de | 26 | #include "system.h" |
805e22b2 | 27 | #include "coretypes.h" |
28 | #include "tm.h" | |
3ef9782d | 29 | |
9dfbe515 | 30 | #include "rtl.h" |
64d5fb6a | 31 | #include "hard-reg-set.h" |
9dfbe515 | 32 | #include "tree.h" |
9ed99284 | 33 | #include "varasm.h" |
34 | #include "stor-layout.h" | |
7953c610 | 35 | #include "tm_p.h" |
9dfbe515 | 36 | #include "flags.h" |
485aaaaf | 37 | #include "except.h" |
a3020f2f | 38 | #include "hashtab.h" |
39 | #include "hash-set.h" | |
40 | #include "vec.h" | |
41 | #include "machmode.h" | |
42 | #include "input.h" | |
9dfbe515 | 43 | #include "function.h" |
9dfbe515 | 44 | #include "insn-config.h" |
9dfbe515 | 45 | #include "expr.h" |
d8fc4d0b | 46 | #include "libfuncs.h" |
9dfbe515 | 47 | #include "recog.h" |
0b205f4c | 48 | #include "diagnostic-core.h" |
cd03a192 | 49 | #include "output.h" |
20325f61 | 50 | #include "langhooks.h" |
cd0fe062 | 51 | #include "predict.h" |
34517c64 | 52 | #include "insn-codes.h" |
315e4c10 | 53 | #include "optabs.h" |
45550790 | 54 | #include "target.h" |
94ea8568 | 55 | #include "cfganal.h" |
bc61cadb | 56 | #include "basic-block.h" |
57 | #include "tree-ssa-alias.h" | |
58 | #include "internal-fn.h" | |
59 | #include "gimple-expr.h" | |
60 | #include "is-a.h" | |
16c9337c | 61 | #include "gimple.h" |
67d6c12b | 62 | #include "regs.h" |
4527a0e8 | 63 | #include "alloc-pool.h" |
abd3e6b5 | 64 | #include "pretty-print.h" |
7e0c8808 | 65 | #include "params.h" |
b9ed1410 | 66 | #include "dumpfile.h" |
f7715905 | 67 | #include "builtins.h" |
0f71a633 | 68 | |
9dfbe515 | 69 | \f |
70 | /* Functions and data structures for expanding case statements. */ | |
71 | ||
72 | /* Case label structure, used to hold info on labels within case | |
73 | statements. We handle "range" labels; for a single-value label | |
74 | as in C, the high and low limits are the same. | |
75 | ||
2ca392fd | 76 | We start with a vector of case nodes sorted in ascending order, and |
77 | the default label as the last element in the vector. Before expanding | |
78 | to RTL, we transform this vector into a list linked via the RIGHT | |
79 | fields in the case_node struct. Nodes with higher case values are | |
80 | later in the list. | |
81 | ||
82 | Switch statements can be output in three forms. A branch table is | |
83 | used if there are more than a few labels and the labels are dense | |
9dfbe515 | 84 | within the range between the smallest and largest case value. If a |
85 | branch table is used, no further manipulations are done with the case | |
86 | node chain. | |
87 | ||
88 | The alternative to the use of a branch table is to generate a series | |
89 | of compare and jump insns. When that is done, we use the LEFT, RIGHT, | |
90 | and PARENT fields to hold a binary tree. Initially the tree is | |
b60acb0b | 91 | totally unbalanced, with everything on the right. We balance the tree |
92 | with nodes on the left having lower case values than the parent | |
9dfbe515 | 93 | and nodes on the right having higher values. We then output the tree |
2ca392fd | 94 | in order. |
95 | ||
96 | For very small, suitable switch statements, we can generate a series | |
97 | of simple bit test and branches instead. */ | |
9dfbe515 | 98 | |
4527a0e8 | 99 | struct case_node |
9dfbe515 | 100 | { |
101 | struct case_node *left; /* Left son in binary tree */ | |
102 | struct case_node *right; /* Right son in binary tree; also node chain */ | |
103 | struct case_node *parent; /* Parent of node in binary tree */ | |
104 | tree low; /* Lowest index value for this label */ | |
105 | tree high; /* Highest index value for this label */ | |
106 | tree code_label; /* Label to jump to when node matches */ | |
584abc98 | 107 | int prob; /* Probability of taking this case. */ |
108 | /* Probability of reaching subtree rooted at this node */ | |
109 | int subtree_prob; | |
9dfbe515 | 110 | }; |
111 | ||
112 | typedef struct case_node case_node; | |
113 | typedef struct case_node *case_node_ptr; | |
114 | ||
584abc98 | 115 | extern basic_block label_to_block_fn (struct function *, tree); |
9dfbe515 | 116 | \f |
78f55ca8 | 117 | static bool check_unique_operand_names (tree, tree, tree); |
118 | static char *resolve_operand_name_1 (char *, tree, tree, tree); | |
60b8c5b3 | 119 | static void balance_case_nodes (case_node_ptr *, case_node_ptr); |
120 | static int node_has_low_bound (case_node_ptr, tree); | |
121 | static int node_has_high_bound (case_node_ptr, tree); | |
122 | static int node_is_bounded (case_node_ptr, tree); | |
584abc98 | 123 | static void emit_case_nodes (rtx, case_node_ptr, rtx, int, tree); |
9dfbe515 | 124 | \f |
125 | /* Return the rtx-label that corresponds to a LABEL_DECL, | |
126 | creating it if necessary. */ | |
127 | ||
128 | rtx | |
60b8c5b3 | 129 | label_rtx (tree label) |
9dfbe515 | 130 | { |
04e579b6 | 131 | gcc_assert (TREE_CODE (label) == LABEL_DECL); |
9dfbe515 | 132 | |
0e8e37b2 | 133 | if (!DECL_RTL_SET_P (label)) |
4ee9c684 | 134 | { |
79f6a8ed | 135 | rtx_code_label *r = gen_label_rtx (); |
4ee9c684 | 136 | SET_DECL_RTL (label, r); |
137 | if (FORCED_LABEL (label) || DECL_NONLOCAL (label)) | |
138 | LABEL_PRESERVE_P (r) = 1; | |
139 | } | |
9dfbe515 | 140 | |
0e8e37b2 | 141 | return DECL_RTL (label); |
9dfbe515 | 142 | } |
143 | ||
78a75ebd | 144 | /* As above, but also put it on the forced-reference list of the |
145 | function that contains it. */ | |
146 | rtx | |
60b8c5b3 | 147 | force_label_rtx (tree label) |
78a75ebd | 148 | { |
231c0441 | 149 | rtx_insn *ref = as_a <rtx_insn *> (label_rtx (label)); |
78a75ebd | 150 | tree function = decl_function_context (label); |
78a75ebd | 151 | |
04e579b6 | 152 | gcc_assert (function); |
78a75ebd | 153 | |
231c0441 | 154 | forced_labels = gen_rtx_INSN_LIST (VOIDmode, ref, forced_labels); |
78a75ebd | 155 | return ref; |
156 | } | |
0e8e37b2 | 157 | |
9dfbe515 | 158 | /* Add an unconditional jump to LABEL as the next sequential instruction. */ |
159 | ||
160 | void | |
60b8c5b3 | 161 | emit_jump (rtx label) |
9dfbe515 | 162 | { |
163 | do_pending_stack_adjust (); | |
164 | emit_jump_insn (gen_jump (label)); | |
165 | emit_barrier (); | |
166 | } | |
9dfbe515 | 167 | \f |
168 | /* Handle goto statements and the labels that they can go to. */ | |
169 | ||
170 | /* Specify the location in the RTL code of a label LABEL, | |
171 | which is a LABEL_DECL tree node. | |
172 | ||
173 | This is used for the kind of label that the user can jump to with a | |
174 | goto statement, and for alternatives of a switch or case statement. | |
175 | RTL labels generated for loops and conditionals don't go through here; | |
176 | they are generated directly at the RTL level, by other functions below. | |
177 | ||
178 | Note that this has nothing to do with defining label *names*. | |
179 | Languages vary in how they do that and what that even means. */ | |
180 | ||
181 | void | |
60b8c5b3 | 182 | expand_label (tree label) |
9dfbe515 | 183 | { |
231c0441 | 184 | rtx_insn *label_r = as_a <rtx_insn *> (label_rtx (label)); |
9dfbe515 | 185 | |
186 | do_pending_stack_adjust (); | |
4ee9c684 | 187 | emit_label (label_r); |
9dfbe515 | 188 | if (DECL_NAME (label)) |
189 | LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label)); | |
190 | ||
4ee9c684 | 191 | if (DECL_NONLOCAL (label)) |
192 | { | |
4598ade9 | 193 | expand_builtin_setjmp_receiver (NULL); |
4ee9c684 | 194 | nonlocal_goto_handler_labels |
a4de1c23 | 195 | = gen_rtx_INSN_LIST (VOIDmode, label_r, |
4ee9c684 | 196 | nonlocal_goto_handler_labels); |
197 | } | |
198 | ||
199 | if (FORCED_LABEL (label)) | |
231c0441 | 200 | forced_labels = gen_rtx_INSN_LIST (VOIDmode, label_r, forced_labels); |
491e04ef | 201 | |
4ee9c684 | 202 | if (DECL_NONLOCAL (label) || FORCED_LABEL (label)) |
203 | maybe_set_first_label_num (label_r); | |
9dfbe515 | 204 | } |
ff89ffb2 | 205 | \f |
37c0f956 | 206 | /* Parse the output constraint pointed to by *CONSTRAINT_P. It is the |
207 | OPERAND_NUMth output operand, indexed from zero. There are NINPUTS | |
208 | inputs and NOUTPUTS outputs to this extended-asm. Upon return, | |
209 | *ALLOWS_MEM will be TRUE iff the constraint allows the use of a | |
210 | memory operand. Similarly, *ALLOWS_REG will be TRUE iff the | |
211 | constraint allows the use of a register operand. And, *IS_INOUT | |
212 | will be true if the operand is read-write, i.e., if it is used as | |
213 | an input as well as an output. If *CONSTRAINT_P is not in | |
214 | canonical form, it will be made canonical. (Note that `+' will be | |
de132707 | 215 | replaced with `=' as part of this process.) |
37c0f956 | 216 | |
217 | Returns TRUE if all went well; FALSE if an error occurred. */ | |
218 | ||
219 | bool | |
60b8c5b3 | 220 | parse_output_constraint (const char **constraint_p, int operand_num, |
221 | int ninputs, int noutputs, bool *allows_mem, | |
222 | bool *allows_reg, bool *is_inout) | |
37c0f956 | 223 | { |
224 | const char *constraint = *constraint_p; | |
225 | const char *p; | |
226 | ||
227 | /* Assume the constraint doesn't allow the use of either a register | |
228 | or memory. */ | |
229 | *allows_mem = false; | |
230 | *allows_reg = false; | |
231 | ||
232 | /* Allow the `=' or `+' to not be at the beginning of the string, | |
233 | since it wasn't explicitly documented that way, and there is a | |
234 | large body of code that puts it last. Swap the character to | |
235 | the front, so as not to uglify any place else. */ | |
236 | p = strchr (constraint, '='); | |
237 | if (!p) | |
238 | p = strchr (constraint, '+'); | |
239 | ||
240 | /* If the string doesn't contain an `=', issue an error | |
241 | message. */ | |
242 | if (!p) | |
243 | { | |
eb586f2c | 244 | error ("output operand constraint lacks %<=%>"); |
37c0f956 | 245 | return false; |
246 | } | |
247 | ||
248 | /* If the constraint begins with `+', then the operand is both read | |
249 | from and written to. */ | |
250 | *is_inout = (*p == '+'); | |
251 | ||
37c0f956 | 252 | /* Canonicalize the output constraint so that it begins with `='. */ |
d72a7307 | 253 | if (p != constraint || *is_inout) |
37c0f956 | 254 | { |
255 | char *buf; | |
256 | size_t c_len = strlen (constraint); | |
257 | ||
258 | if (p != constraint) | |
c3ceba8e | 259 | warning (0, "output constraint %qc for operand %d " |
eb586f2c | 260 | "is not at the beginning", |
37c0f956 | 261 | *p, operand_num); |
262 | ||
263 | /* Make a copy of the constraint. */ | |
f7f3687c | 264 | buf = XALLOCAVEC (char, c_len + 1); |
37c0f956 | 265 | strcpy (buf, constraint); |
266 | /* Swap the first character and the `=' or `+'. */ | |
267 | buf[p - constraint] = buf[0]; | |
268 | /* Make sure the first character is an `='. (Until we do this, | |
269 | it might be a `+'.) */ | |
270 | buf[0] = '='; | |
271 | /* Replace the constraint with the canonicalized string. */ | |
272 | *constraint_p = ggc_alloc_string (buf, c_len); | |
273 | constraint = *constraint_p; | |
274 | } | |
275 | ||
276 | /* Loop through the constraint string. */ | |
48ea5577 | 277 | for (p = constraint + 1; *p; p += CONSTRAINT_LEN (*p, p)) |
37c0f956 | 278 | switch (*p) |
279 | { | |
280 | case '+': | |
281 | case '=': | |
eb586f2c | 282 | error ("operand constraint contains incorrectly positioned " |
283 | "%<+%> or %<=%>"); | |
37c0f956 | 284 | return false; |
40734805 | 285 | |
37c0f956 | 286 | case '%': |
287 | if (operand_num + 1 == ninputs + noutputs) | |
288 | { | |
eb586f2c | 289 | error ("%<%%%> constraint used with last operand"); |
37c0f956 | 290 | return false; |
291 | } | |
292 | break; | |
293 | ||
37c0f956 | 294 | case '?': case '!': case '*': case '&': case '#': |
295 | case 'E': case 'F': case 'G': case 'H': | |
296 | case 's': case 'i': case 'n': | |
297 | case 'I': case 'J': case 'K': case 'L': case 'M': | |
298 | case 'N': case 'O': case 'P': case ',': | |
299 | break; | |
300 | ||
301 | case '0': case '1': case '2': case '3': case '4': | |
302 | case '5': case '6': case '7': case '8': case '9': | |
2c7f203c | 303 | case '[': |
37c0f956 | 304 | error ("matching constraint not valid in output operand"); |
305 | return false; | |
306 | ||
307 | case '<': case '>': | |
308 | /* ??? Before flow, auto inc/dec insns are not supposed to exist, | |
309 | excepting those that expand_call created. So match memory | |
310 | and hope. */ | |
311 | *allows_mem = true; | |
312 | break; | |
313 | ||
314 | case 'g': case 'X': | |
315 | *allows_reg = true; | |
316 | *allows_mem = true; | |
317 | break; | |
40734805 | 318 | |
37c0f956 | 319 | default: |
320 | if (!ISALPHA (*p)) | |
321 | break; | |
79bc09fb | 322 | enum constraint_num cn = lookup_constraint (p); |
323 | if (reg_class_for_constraint (cn) != NO_REGS | |
324 | || insn_extra_address_constraint (cn)) | |
37c0f956 | 325 | *allows_reg = true; |
79bc09fb | 326 | else if (insn_extra_memory_constraint (cn)) |
a5004c3d | 327 | *allows_mem = true; |
37c0f956 | 328 | else |
329 | { | |
330 | /* Otherwise we can't assume anything about the nature of | |
331 | the constraint except that it isn't purely registers. | |
332 | Treat it like "g" and hope for the best. */ | |
333 | *allows_reg = true; | |
334 | *allows_mem = true; | |
335 | } | |
37c0f956 | 336 | break; |
337 | } | |
338 | ||
339 | return true; | |
340 | } | |
341 | ||
727dae1b | 342 | /* Similar, but for input constraints. */ |
343 | ||
d7e38994 | 344 | bool |
60b8c5b3 | 345 | parse_input_constraint (const char **constraint_p, int input_num, |
346 | int ninputs, int noutputs, int ninout, | |
347 | const char * const * constraints, | |
348 | bool *allows_mem, bool *allows_reg) | |
727dae1b | 349 | { |
350 | const char *constraint = *constraint_p; | |
351 | const char *orig_constraint = constraint; | |
352 | size_t c_len = strlen (constraint); | |
353 | size_t j; | |
23ec9bd9 | 354 | bool saw_match = false; |
727dae1b | 355 | |
356 | /* Assume the constraint doesn't allow the use of either | |
357 | a register or memory. */ | |
358 | *allows_mem = false; | |
359 | *allows_reg = false; | |
360 | ||
361 | /* Make sure constraint has neither `=', `+', nor '&'. */ | |
362 | ||
48ea5577 | 363 | for (j = 0; j < c_len; j += CONSTRAINT_LEN (constraint[j], constraint+j)) |
727dae1b | 364 | switch (constraint[j]) |
365 | { | |
366 | case '+': case '=': case '&': | |
367 | if (constraint == orig_constraint) | |
368 | { | |
eb586f2c | 369 | error ("input operand constraint contains %qc", constraint[j]); |
727dae1b | 370 | return false; |
371 | } | |
372 | break; | |
373 | ||
374 | case '%': | |
375 | if (constraint == orig_constraint | |
376 | && input_num + 1 == ninputs - ninout) | |
377 | { | |
eb586f2c | 378 | error ("%<%%%> constraint used with last operand"); |
727dae1b | 379 | return false; |
380 | } | |
381 | break; | |
382 | ||
727dae1b | 383 | case '<': case '>': |
384 | case '?': case '!': case '*': case '#': | |
385 | case 'E': case 'F': case 'G': case 'H': | |
386 | case 's': case 'i': case 'n': | |
387 | case 'I': case 'J': case 'K': case 'L': case 'M': | |
388 | case 'N': case 'O': case 'P': case ',': | |
389 | break; | |
390 | ||
391 | /* Whether or not a numeric constraint allows a register is | |
392 | decided by the matching constraint, and so there is no need | |
393 | to do anything special with them. We must handle them in | |
394 | the default case, so that we don't unnecessarily force | |
395 | operands to memory. */ | |
396 | case '0': case '1': case '2': case '3': case '4': | |
397 | case '5': case '6': case '7': case '8': case '9': | |
398 | { | |
399 | char *end; | |
400 | unsigned long match; | |
401 | ||
23ec9bd9 | 402 | saw_match = true; |
403 | ||
727dae1b | 404 | match = strtoul (constraint + j, &end, 10); |
405 | if (match >= (unsigned long) noutputs) | |
406 | { | |
407 | error ("matching constraint references invalid operand number"); | |
408 | return false; | |
409 | } | |
410 | ||
411 | /* Try and find the real constraint for this dup. Only do this | |
412 | if the matching constraint is the only alternative. */ | |
413 | if (*end == '\0' | |
414 | && (j == 0 || (j == 1 && constraint[0] == '%'))) | |
415 | { | |
416 | constraint = constraints[match]; | |
417 | *constraint_p = constraint; | |
418 | c_len = strlen (constraint); | |
419 | j = 0; | |
48ea5577 | 420 | /* ??? At the end of the loop, we will skip the first part of |
421 | the matched constraint. This assumes not only that the | |
422 | other constraint is an output constraint, but also that | |
423 | the '=' or '+' come first. */ | |
727dae1b | 424 | break; |
425 | } | |
426 | else | |
427 | j = end - constraint; | |
48ea5577 | 428 | /* Anticipate increment at end of loop. */ |
429 | j--; | |
727dae1b | 430 | } |
431 | /* Fall through. */ | |
432 | ||
727dae1b | 433 | case 'g': case 'X': |
434 | *allows_reg = true; | |
435 | *allows_mem = true; | |
436 | break; | |
437 | ||
438 | default: | |
439 | if (! ISALPHA (constraint[j])) | |
440 | { | |
eb586f2c | 441 | error ("invalid punctuation %qc in constraint", constraint[j]); |
727dae1b | 442 | return false; |
443 | } | |
79bc09fb | 444 | enum constraint_num cn = lookup_constraint (constraint + j); |
445 | if (reg_class_for_constraint (cn) != NO_REGS | |
446 | || insn_extra_address_constraint (cn)) | |
a5004c3d | 447 | *allows_reg = true; |
79bc09fb | 448 | else if (insn_extra_memory_constraint (cn)) |
a5004c3d | 449 | *allows_mem = true; |
727dae1b | 450 | else |
451 | { | |
452 | /* Otherwise we can't assume anything about the nature of | |
453 | the constraint except that it isn't purely registers. | |
454 | Treat it like "g" and hope for the best. */ | |
455 | *allows_reg = true; | |
456 | *allows_mem = true; | |
457 | } | |
727dae1b | 458 | break; |
459 | } | |
460 | ||
23ec9bd9 | 461 | if (saw_match && !*allows_reg) |
c3ceba8e | 462 | warning (0, "matching constraint does not allow a register"); |
23ec9bd9 | 463 | |
727dae1b | 464 | return true; |
465 | } | |
466 | ||
2389b26b | 467 | /* Return DECL iff there's an overlap between *REGS and DECL, where DECL |
468 | can be an asm-declared register. Called via walk_tree. */ | |
3d52d305 | 469 | |
2389b26b | 470 | static tree |
471 | decl_overlaps_hard_reg_set_p (tree *declp, int *walk_subtrees ATTRIBUTE_UNUSED, | |
472 | void *data) | |
3d52d305 | 473 | { |
2389b26b | 474 | tree decl = *declp; |
f7f3687c | 475 | const HARD_REG_SET *const regs = (const HARD_REG_SET *) data; |
2389b26b | 476 | |
56753e9d | 477 | if (TREE_CODE (decl) == VAR_DECL) |
3d52d305 | 478 | { |
56753e9d | 479 | if (DECL_HARD_REGISTER (decl) |
2389b26b | 480 | && REG_P (DECL_RTL (decl)) |
481 | && REGNO (DECL_RTL (decl)) < FIRST_PSEUDO_REGISTER) | |
482 | { | |
483 | rtx reg = DECL_RTL (decl); | |
a2c6f0b7 | 484 | |
485 | if (overlaps_hard_reg_set_p (*regs, GET_MODE (reg), REGNO (reg))) | |
486 | return decl; | |
2389b26b | 487 | } |
488 | walk_subtrees = 0; | |
64d5fb6a | 489 | } |
56753e9d | 490 | else if (TYPE_P (decl) || TREE_CODE (decl) == PARM_DECL) |
2389b26b | 491 | walk_subtrees = 0; |
492 | return NULL_TREE; | |
64d5fb6a | 493 | } |
494 | ||
2389b26b | 495 | /* If there is an overlap between *REGS and DECL, return the first overlap |
496 | found. */ | |
497 | tree | |
498 | tree_overlaps_hard_reg_set (tree decl, HARD_REG_SET *regs) | |
499 | { | |
500 | return walk_tree (&decl, decl_overlaps_hard_reg_set_p, regs, NULL); | |
501 | } | |
64d5fb6a | 502 | |
2c7f203c | 503 | |
504 | /* A subroutine of expand_asm_operands. Check that all operand names | |
505 | are unique. Return true if so. We rely on the fact that these names | |
506 | are identifiers, and so have been canonicalized by get_identifier, | |
507 | so all we need are pointer comparisons. */ | |
508 | ||
509 | static bool | |
78f55ca8 | 510 | check_unique_operand_names (tree outputs, tree inputs, tree labels) |
2c7f203c | 511 | { |
1aed71d6 | 512 | tree i, j, i_name = NULL_TREE; |
2c7f203c | 513 | |
514 | for (i = outputs; i ; i = TREE_CHAIN (i)) | |
515 | { | |
1aed71d6 | 516 | i_name = TREE_PURPOSE (TREE_PURPOSE (i)); |
2c7f203c | 517 | if (! i_name) |
518 | continue; | |
519 | ||
520 | for (j = TREE_CHAIN (i); j ; j = TREE_CHAIN (j)) | |
e3189f72 | 521 | if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j)))) |
2c7f203c | 522 | goto failure; |
523 | } | |
524 | ||
525 | for (i = inputs; i ; i = TREE_CHAIN (i)) | |
526 | { | |
1aed71d6 | 527 | i_name = TREE_PURPOSE (TREE_PURPOSE (i)); |
2c7f203c | 528 | if (! i_name) |
529 | continue; | |
530 | ||
531 | for (j = TREE_CHAIN (i); j ; j = TREE_CHAIN (j)) | |
e3189f72 | 532 | if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j)))) |
2c7f203c | 533 | goto failure; |
534 | for (j = outputs; j ; j = TREE_CHAIN (j)) | |
e3189f72 | 535 | if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j)))) |
2c7f203c | 536 | goto failure; |
537 | } | |
538 | ||
78f55ca8 | 539 | for (i = labels; i ; i = TREE_CHAIN (i)) |
540 | { | |
1aed71d6 | 541 | i_name = TREE_PURPOSE (i); |
78f55ca8 | 542 | if (! i_name) |
543 | continue; | |
544 | ||
545 | for (j = TREE_CHAIN (i); j ; j = TREE_CHAIN (j)) | |
546 | if (simple_cst_equal (i_name, TREE_PURPOSE (j))) | |
547 | goto failure; | |
548 | for (j = inputs; j ; j = TREE_CHAIN (j)) | |
549 | if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j)))) | |
550 | goto failure; | |
551 | } | |
552 | ||
2c7f203c | 553 | return true; |
554 | ||
555 | failure: | |
1aed71d6 | 556 | error ("duplicate asm operand name %qs", TREE_STRING_POINTER (i_name)); |
2c7f203c | 557 | return false; |
558 | } | |
559 | ||
560 | /* A subroutine of expand_asm_operands. Resolve the names of the operands | |
561 | in *POUTPUTS and *PINPUTS to numbers, and replace the name expansions in | |
562 | STRING and in the constraints to those numbers. */ | |
563 | ||
ef13e68f | 564 | tree |
78f55ca8 | 565 | resolve_asm_operand_names (tree string, tree outputs, tree inputs, tree labels) |
2c7f203c | 566 | { |
ef13e68f | 567 | char *buffer; |
2c7f203c | 568 | char *p; |
957697db | 569 | const char *c; |
2c7f203c | 570 | tree t; |
571 | ||
78f55ca8 | 572 | check_unique_operand_names (outputs, inputs, labels); |
d7e38994 | 573 | |
ef13e68f | 574 | /* Substitute [<name>] in input constraint strings. There should be no |
575 | named operands in output constraints. */ | |
576 | for (t = inputs; t ; t = TREE_CHAIN (t)) | |
577 | { | |
957697db | 578 | c = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t))); |
ef13e68f | 579 | if (strchr (c, '[') != NULL) |
580 | { | |
581 | p = buffer = xstrdup (c); | |
582 | while ((p = strchr (p, '[')) != NULL) | |
78f55ca8 | 583 | p = resolve_operand_name_1 (p, outputs, inputs, NULL); |
ef13e68f | 584 | TREE_VALUE (TREE_PURPOSE (t)) |
585 | = build_string (strlen (buffer), buffer); | |
586 | free (buffer); | |
587 | } | |
588 | } | |
589 | ||
957697db | 590 | /* Now check for any needed substitutions in the template. */ |
591 | c = TREE_STRING_POINTER (string); | |
592 | while ((c = strchr (c, '%')) != NULL) | |
2c7f203c | 593 | { |
957697db | 594 | if (c[1] == '[') |
595 | break; | |
596 | else if (ISALPHA (c[1]) && c[2] == '[') | |
597 | break; | |
f9477390 | 598 | else |
599 | { | |
ef1c7233 | 600 | c += 1 + (c[1] == '%'); |
f9477390 | 601 | continue; |
602 | } | |
2c7f203c | 603 | } |
604 | ||
957697db | 605 | if (c) |
606 | { | |
607 | /* OK, we need to make a copy so we can perform the substitutions. | |
608 | Assume that we will not need extra space--we get to remove '[' | |
609 | and ']', which means we cannot have a problem until we have more | |
610 | than 999 operands. */ | |
611 | buffer = xstrdup (TREE_STRING_POINTER (string)); | |
612 | p = buffer + (c - TREE_STRING_POINTER (string)); | |
491e04ef | 613 | |
957697db | 614 | while ((p = strchr (p, '%')) != NULL) |
615 | { | |
616 | if (p[1] == '[') | |
617 | p += 1; | |
618 | else if (ISALPHA (p[1]) && p[2] == '[') | |
619 | p += 2; | |
620 | else | |
621 | { | |
ef1c7233 | 622 | p += 1 + (p[1] == '%'); |
957697db | 623 | continue; |
624 | } | |
625 | ||
78f55ca8 | 626 | p = resolve_operand_name_1 (p, outputs, inputs, labels); |
957697db | 627 | } |
628 | ||
629 | string = build_string (strlen (buffer), buffer); | |
630 | free (buffer); | |
631 | } | |
2c7f203c | 632 | |
2c7f203c | 633 | return string; |
634 | } | |
635 | ||
636 | /* A subroutine of resolve_operand_names. P points to the '[' for a | |
637 | potential named operand of the form [<name>]. In place, replace | |
40734805 | 638 | the name and brackets with a number. Return a pointer to the |
2c7f203c | 639 | balance of the string after substitution. */ |
640 | ||
641 | static char * | |
78f55ca8 | 642 | resolve_operand_name_1 (char *p, tree outputs, tree inputs, tree labels) |
2c7f203c | 643 | { |
644 | char *q; | |
645 | int op; | |
646 | tree t; | |
2c7f203c | 647 | |
648 | /* Collect the operand name. */ | |
78f55ca8 | 649 | q = strchr (++p, ']'); |
2c7f203c | 650 | if (!q) |
651 | { | |
652 | error ("missing close brace for named operand"); | |
653 | return strchr (p, '\0'); | |
654 | } | |
78f55ca8 | 655 | *q = '\0'; |
2c7f203c | 656 | |
657 | /* Resolve the name to a number. */ | |
658 | for (op = 0, t = outputs; t ; t = TREE_CHAIN (t), op++) | |
659 | { | |
e3189f72 | 660 | tree name = TREE_PURPOSE (TREE_PURPOSE (t)); |
78f55ca8 | 661 | if (name && strcmp (TREE_STRING_POINTER (name), p) == 0) |
662 | goto found; | |
2c7f203c | 663 | } |
664 | for (t = inputs; t ; t = TREE_CHAIN (t), op++) | |
665 | { | |
e3189f72 | 666 | tree name = TREE_PURPOSE (TREE_PURPOSE (t)); |
78f55ca8 | 667 | if (name && strcmp (TREE_STRING_POINTER (name), p) == 0) |
668 | goto found; | |
669 | } | |
670 | for (t = labels; t ; t = TREE_CHAIN (t), op++) | |
671 | { | |
672 | tree name = TREE_PURPOSE (t); | |
673 | if (name && strcmp (TREE_STRING_POINTER (name), p) == 0) | |
674 | goto found; | |
2c7f203c | 675 | } |
676 | ||
78f55ca8 | 677 | error ("undefined named operand %qs", identifier_to_locale (p)); |
2c7f203c | 678 | op = 0; |
2c7f203c | 679 | |
78f55ca8 | 680 | found: |
2c7f203c | 681 | /* Replace the name with the number. Unfortunately, not all libraries |
682 | get the return value of sprintf correct, so search for the end of the | |
683 | generated string by hand. */ | |
78f55ca8 | 684 | sprintf (--p, "%d", op); |
2c7f203c | 685 | p = strchr (p, '\0'); |
686 | ||
687 | /* Verify the no extra buffer space assumption. */ | |
04e579b6 | 688 | gcc_assert (p <= q); |
2c7f203c | 689 | |
690 | /* Shift the rest of the buffer down to fill the gap. */ | |
691 | memmove (p, q + 1, strlen (q + 1) + 1); | |
692 | ||
693 | return p; | |
694 | } | |
9dfbe515 | 695 | \f |
9dfbe515 | 696 | |
62380d2d | 697 | /* Generate RTL to return directly from the current function. |
698 | (That is, we bypass any return value.) */ | |
699 | ||
700 | void | |
701 | expand_naked_return (void) | |
702 | { | |
6388f9f7 | 703 | rtx end_label; |
62380d2d | 704 | |
705 | clear_pending_stack_adjust (); | |
706 | do_pending_stack_adjust (); | |
62380d2d | 707 | |
6388f9f7 | 708 | end_label = naked_return_label; |
62380d2d | 709 | if (end_label == 0) |
710 | end_label = naked_return_label = gen_label_rtx (); | |
6388f9f7 | 711 | |
712 | emit_jump (end_label); | |
62380d2d | 713 | } |
714 | ||
584abc98 | 715 | /* Generate code to jump to LABEL if OP0 and OP1 are equal in mode MODE. PROB |
716 | is the probability of jumping to LABEL. */ | |
af68b5a9 | 717 | static void |
3754d046 | 718 | do_jump_if_equal (machine_mode mode, rtx op0, rtx op1, rtx label, |
584abc98 | 719 | int unsignedp, int prob) |
af68b5a9 | 720 | { |
584abc98 | 721 | gcc_assert (prob <= REG_BR_PROB_BASE); |
af68b5a9 | 722 | do_compare_rtx_and_jump (op0, op1, EQ, unsignedp, mode, |
584abc98 | 723 | NULL_RTX, NULL_RTX, label, prob); |
af68b5a9 | 724 | } |
9dfbe515 | 725 | \f |
fcb807f8 | 726 | /* Do the insertion of a case label into case_list. The labels are |
727 | fed to us in descending order from the sorted vector of case labels used | |
2ca392fd | 728 | in the tree part of the middle end. So the list we construct is |
584abc98 | 729 | sorted in ascending order. |
730 | ||
731 | LABEL is the case label to be inserted. LOW and HIGH are the bounds | |
732 | against which the index is compared to jump to LABEL and PROB is the | |
733 | estimated probability LABEL is reached from the switch statement. */ | |
33fbacb1 | 734 | |
8bacfa58 | 735 | static struct case_node * |
af68b5a9 | 736 | add_case_node (struct case_node *head, tree low, tree high, |
584abc98 | 737 | tree label, int prob, alloc_pool case_node_pool) |
33fbacb1 | 738 | { |
2ca392fd | 739 | struct case_node *r; |
33fbacb1 | 740 | |
bfb10994 | 741 | gcc_checking_assert (low); |
af68b5a9 | 742 | gcc_checking_assert (high && (TREE_TYPE (low) == TREE_TYPE (high))); |
225ec6aa | 743 | |
af68b5a9 | 744 | /* Add this label to the chain. */ |
4527a0e8 | 745 | r = (struct case_node *) pool_alloc (case_node_pool); |
af68b5a9 | 746 | r->low = low; |
747 | r->high = high; | |
33fbacb1 | 748 | r->code_label = label; |
2ca392fd | 749 | r->parent = r->left = NULL; |
584abc98 | 750 | r->prob = prob; |
751 | r->subtree_prob = prob; | |
fcb807f8 | 752 | r->right = head; |
753 | return r; | |
9dfbe515 | 754 | } |
9dfbe515 | 755 | \f |
5e9ee578 | 756 | /* Dump ROOT, a list or tree of case nodes, to file. */ |
757 | ||
758 | static void | |
759 | dump_case_nodes (FILE *f, struct case_node *root, | |
760 | int indent_step, int indent_level) | |
761 | { | |
5e9ee578 | 762 | if (root == 0) |
763 | return; | |
764 | indent_level++; | |
765 | ||
766 | dump_case_nodes (f, root->left, indent_step, indent_level); | |
767 | ||
5e9ee578 | 768 | fputs (";; ", f); |
49523e2f | 769 | fprintf (f, "%*s", indent_step * indent_level, ""); |
770 | print_dec (root->low, f, TYPE_SIGN (TREE_TYPE (root->low))); | |
771 | if (!tree_int_cst_equal (root->low, root->high)) | |
772 | { | |
773 | fprintf (f, " ... "); | |
774 | print_dec (root->high, f, TYPE_SIGN (TREE_TYPE (root->high))); | |
775 | } | |
5e9ee578 | 776 | fputs ("\n", f); |
777 | ||
778 | dump_case_nodes (f, root->right, indent_step, indent_level); | |
779 | } | |
780 | \f | |
bf83534c | 781 | #ifndef HAVE_casesi |
782 | #define HAVE_casesi 0 | |
783 | #endif | |
784 | ||
785 | #ifndef HAVE_tablejump | |
786 | #define HAVE_tablejump 0 | |
787 | #endif | |
788 | ||
7e0c8808 | 789 | /* Return the smallest number of different values for which it is best to use a |
790 | jump-table instead of a tree of conditional branches. */ | |
791 | ||
792 | static unsigned int | |
793 | case_values_threshold (void) | |
794 | { | |
795 | unsigned int threshold = PARAM_VALUE (PARAM_CASE_VALUES_THRESHOLD); | |
796 | ||
797 | if (threshold == 0) | |
798 | threshold = targetm.case_values_threshold (); | |
799 | ||
800 | return threshold; | |
801 | } | |
802 | ||
5e9ee578 | 803 | /* Return true if a switch should be expanded as a decision tree. |
804 | RANGE is the difference between highest and lowest case. | |
805 | UNIQ is number of unique case node targets, not counting the default case. | |
806 | COUNT is the number of comparisons needed, not counting the default case. */ | |
9dfbe515 | 807 | |
5e9ee578 | 808 | static bool |
809 | expand_switch_as_decision_tree_p (tree range, | |
810 | unsigned int uniq ATTRIBUTE_UNUSED, | |
811 | unsigned int count) | |
9dfbe515 | 812 | { |
5e9ee578 | 813 | int max_ratio; |
814 | ||
815 | /* If neither casesi or tablejump is available, or flag_jump_tables | |
816 | over-ruled us, we really have no choice. */ | |
817 | if (!HAVE_casesi && !HAVE_tablejump) | |
818 | return true; | |
819 | if (!flag_jump_tables) | |
820 | return true; | |
d5417a49 | 821 | #ifndef ASM_OUTPUT_ADDR_DIFF_ELT |
822 | if (flag_pic) | |
823 | return true; | |
824 | #endif | |
5e9ee578 | 825 | |
826 | /* If the switch is relatively small such that the cost of one | |
827 | indirect jump on the target are higher than the cost of a | |
828 | decision tree, go with the decision tree. | |
829 | ||
830 | If range of values is much bigger than number of values, | |
831 | or if it is too large to represent in a HOST_WIDE_INT, | |
832 | make a sequence of conditional branches instead of a dispatch. | |
833 | ||
834 | The definition of "much bigger" depends on whether we are | |
835 | optimizing for size or for speed. If the former, the maximum | |
836 | ratio range/count = 3, because this was found to be the optimal | |
837 | ratio for size on i686-pc-linux-gnu, see PR11823. The ratio | |
838 | 10 is much older, and was probably selected after an extensive | |
839 | benchmarking investigation on numerous platforms. Or maybe it | |
840 | just made sense to someone at some point in the history of GCC, | |
841 | who knows... */ | |
842 | max_ratio = optimize_insn_for_size_p () ? 3 : 10; | |
843 | if (count < case_values_threshold () | |
e913b5cd | 844 | || ! tree_fits_uhwi_p (range) |
5e9ee578 | 845 | || compare_tree_int (range, max_ratio * count) > 0) |
846 | return true; | |
649d8da6 | 847 | |
5e9ee578 | 848 | return false; |
849 | } | |
fcb807f8 | 850 | |
5e9ee578 | 851 | /* Generate a decision tree, switching on INDEX_EXPR and jumping to |
852 | one of the labels in CASE_LIST or to the DEFAULT_LABEL. | |
584abc98 | 853 | DEFAULT_PROB is the estimated probability that it jumps to |
854 | DEFAULT_LABEL. | |
5e9ee578 | 855 | |
856 | We generate a binary decision tree to select the appropriate target | |
857 | code. This is done as follows: | |
fcb807f8 | 858 | |
5e9ee578 | 859 | If the index is a short or char that we do not have |
860 | an insn to handle comparisons directly, convert it to | |
861 | a full integer now, rather than letting each comparison | |
862 | generate the conversion. | |
863 | ||
864 | Load the index into a register. | |
865 | ||
866 | The list of cases is rearranged into a binary tree, | |
867 | nearly optimal assuming equal probability for each case. | |
868 | ||
869 | The tree is transformed into RTL, eliminating redundant | |
870 | test conditions at the same time. | |
871 | ||
872 | If program flow could reach the end of the decision tree | |
873 | an unconditional jump to the default code is emitted. | |
fcb807f8 | 874 | |
5e9ee578 | 875 | The above process is unaware of the CFG. The caller has to fix up |
876 | the CFG itself. This is done in cfgexpand.c. */ | |
fcb807f8 | 877 | |
5e9ee578 | 878 | static void |
879 | emit_case_decision_tree (tree index_expr, tree index_type, | |
584abc98 | 880 | struct case_node *case_list, rtx default_label, |
881 | int default_prob) | |
5e9ee578 | 882 | { |
883 | rtx index = expand_normal (index_expr); | |
884 | ||
885 | if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT | |
886 | && ! have_insn_for (COMPARE, GET_MODE (index))) | |
887 | { | |
888 | int unsignedp = TYPE_UNSIGNED (index_type); | |
3754d046 | 889 | machine_mode wider_mode; |
5e9ee578 | 890 | for (wider_mode = GET_MODE (index); wider_mode != VOIDmode; |
891 | wider_mode = GET_MODE_WIDER_MODE (wider_mode)) | |
892 | if (have_insn_for (COMPARE, wider_mode)) | |
893 | { | |
894 | index = convert_to_mode (wider_mode, index, unsignedp); | |
895 | break; | |
896 | } | |
897 | } | |
4527a0e8 | 898 | |
9dfbe515 | 899 | do_pending_stack_adjust (); |
900 | ||
5e9ee578 | 901 | if (MEM_P (index)) |
9dfbe515 | 902 | { |
5e9ee578 | 903 | index = copy_to_reg (index); |
904 | if (TREE_CODE (index_expr) == SSA_NAME) | |
905 | set_reg_attrs_for_decl_rtl (SSA_NAME_VAR (index_expr), index); | |
906 | } | |
8bacfa58 | 907 | |
5e9ee578 | 908 | balance_case_nodes (&case_list, NULL); |
32dc5157 | 909 | |
b9ed1410 | 910 | if (dump_file && (dump_flags & TDF_DETAILS)) |
5e9ee578 | 911 | { |
912 | int indent_step = ceil_log2 (TYPE_PRECISION (index_type)) + 2; | |
913 | fprintf (dump_file, ";; Expanding GIMPLE switch as decision tree:\n"); | |
914 | dump_case_nodes (dump_file, case_list, indent_step, 0); | |
915 | } | |
9d6b2687 | 916 | |
584abc98 | 917 | emit_case_nodes (index, case_list, default_label, default_prob, index_type); |
5e9ee578 | 918 | if (default_label) |
919 | emit_jump (default_label); | |
920 | } | |
8bacfa58 | 921 | |
584abc98 | 922 | /* Return the sum of probabilities of outgoing edges of basic block BB. */ |
923 | ||
924 | static int | |
925 | get_outgoing_edge_probs (basic_block bb) | |
926 | { | |
927 | edge e; | |
928 | edge_iterator ei; | |
929 | int prob_sum = 0; | |
e065d0bc | 930 | if (!bb) |
931 | return 0; | |
9af5ce0c | 932 | FOR_EACH_EDGE (e, ei, bb->succs) |
584abc98 | 933 | prob_sum += e->probability; |
934 | return prob_sum; | |
935 | } | |
936 | ||
937 | /* Computes the conditional probability of jumping to a target if the branch | |
938 | instruction is executed. | |
939 | TARGET_PROB is the estimated probability of jumping to a target relative | |
940 | to some basic block BB. | |
941 | BASE_PROB is the probability of reaching the branch instruction relative | |
942 | to the same basic block BB. */ | |
943 | ||
944 | static inline int | |
945 | conditional_probability (int target_prob, int base_prob) | |
946 | { | |
947 | if (base_prob > 0) | |
948 | { | |
949 | gcc_assert (target_prob >= 0); | |
950 | gcc_assert (target_prob <= base_prob); | |
f9d4b7f4 | 951 | return GCOV_COMPUTE_SCALE (target_prob, base_prob); |
584abc98 | 952 | } |
953 | return -1; | |
954 | } | |
955 | ||
5e9ee578 | 956 | /* Generate a dispatch tabler, switching on INDEX_EXPR and jumping to |
957 | one of the labels in CASE_LIST or to the DEFAULT_LABEL. | |
958 | MINVAL, MAXVAL, and RANGE are the extrema and range of the case | |
584abc98 | 959 | labels in CASE_LIST. STMT_BB is the basic block containing the statement. |
8bacfa58 | 960 | |
5e9ee578 | 961 | First, a jump insn is emitted. First we try "casesi". If that |
962 | fails, try "tablejump". A target *must* have one of them (or both). | |
963 | ||
964 | Then, a table with the target labels is emitted. | |
965 | ||
966 | The process is unaware of the CFG. The caller has to fix up | |
967 | the CFG itself. This is done in cfgexpand.c. */ | |
968 | ||
969 | static void | |
970 | emit_case_dispatch_table (tree index_expr, tree index_type, | |
971 | struct case_node *case_list, rtx default_label, | |
584abc98 | 972 | tree minval, tree maxval, tree range, |
973 | basic_block stmt_bb) | |
5e9ee578 | 974 | { |
975 | int i, ncases; | |
976 | struct case_node *n; | |
977 | rtx *labelvec; | |
978 | rtx fallback_label = label_rtx (case_list->code_label); | |
79f6a8ed | 979 | rtx_code_label *table_label = gen_label_rtx (); |
584abc98 | 980 | bool has_gaps = false; |
9af5ce0c | 981 | edge default_edge = stmt_bb ? EDGE_SUCC (stmt_bb, 0) : NULL; |
e065d0bc | 982 | int default_prob = default_edge ? default_edge->probability : 0; |
584abc98 | 983 | int base = get_outgoing_edge_probs (stmt_bb); |
984 | bool try_with_tablejump = false; | |
985 | ||
986 | int new_default_prob = conditional_probability (default_prob, | |
987 | base); | |
9dfbe515 | 988 | |
5e9ee578 | 989 | if (! try_casesi (index_type, index_expr, minval, range, |
584abc98 | 990 | table_label, default_label, fallback_label, |
991 | new_default_prob)) | |
5e9ee578 | 992 | { |
5e9ee578 | 993 | /* Index jumptables from zero for suitable values of minval to avoid |
994 | a subtraction. For the rationale see: | |
995 | "http://gcc.gnu.org/ml/gcc-patches/2001-10/msg01234.html". */ | |
996 | if (optimize_insn_for_speed_p () | |
997 | && compare_tree_int (minval, 0) > 0 | |
998 | && compare_tree_int (minval, 3) < 0) | |
9dfbe515 | 999 | { |
5e9ee578 | 1000 | minval = build_int_cst (index_type, 0); |
1001 | range = maxval; | |
584abc98 | 1002 | has_gaps = true; |
9dfbe515 | 1003 | } |
584abc98 | 1004 | try_with_tablejump = true; |
5e9ee578 | 1005 | } |
9dfbe515 | 1006 | |
5e9ee578 | 1007 | /* Get table of labels to jump to, in order of case index. */ |
9dfbe515 | 1008 | |
e913b5cd | 1009 | ncases = tree_to_shwi (range) + 1; |
5e9ee578 | 1010 | labelvec = XALLOCAVEC (rtx, ncases); |
1011 | memset (labelvec, 0, ncases * sizeof (rtx)); | |
9dfbe515 | 1012 | |
5e9ee578 | 1013 | for (n = case_list; n; n = n->right) |
1014 | { | |
1015 | /* Compute the low and high bounds relative to the minimum | |
1016 | value since that should fit in a HOST_WIDE_INT while the | |
1017 | actual values may not. */ | |
1018 | HOST_WIDE_INT i_low | |
e913b5cd | 1019 | = tree_to_uhwi (fold_build2 (MINUS_EXPR, index_type, |
1020 | n->low, minval)); | |
5e9ee578 | 1021 | HOST_WIDE_INT i_high |
e913b5cd | 1022 | = tree_to_uhwi (fold_build2 (MINUS_EXPR, index_type, |
1023 | n->high, minval)); | |
5e9ee578 | 1024 | HOST_WIDE_INT i; |
1025 | ||
1026 | for (i = i_low; i <= i_high; i ++) | |
1027 | labelvec[i] | |
1028 | = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label)); | |
1029 | } | |
9dfbe515 | 1030 | |
5e9ee578 | 1031 | /* Fill in the gaps with the default. We may have gaps at |
1032 | the beginning if we tried to avoid the minval subtraction, | |
1033 | so substitute some label even if the default label was | |
1034 | deemed unreachable. */ | |
1035 | if (!default_label) | |
1036 | default_label = fallback_label; | |
1037 | for (i = 0; i < ncases; i++) | |
1038 | if (labelvec[i] == 0) | |
584abc98 | 1039 | { |
1040 | has_gaps = true; | |
1041 | labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label); | |
1042 | } | |
1043 | ||
1044 | if (has_gaps) | |
1045 | { | |
1046 | /* There is at least one entry in the jump table that jumps | |
1047 | to default label. The default label can either be reached | |
1048 | through the indirect jump or the direct conditional jump | |
1049 | before that. Split the probability of reaching the | |
1050 | default label among these two jumps. */ | |
1051 | new_default_prob = conditional_probability (default_prob/2, | |
1052 | base); | |
1053 | default_prob /= 2; | |
1054 | base -= default_prob; | |
1055 | } | |
1056 | else | |
1057 | { | |
1058 | base -= default_prob; | |
1059 | default_prob = 0; | |
1060 | } | |
1061 | ||
e065d0bc | 1062 | if (default_edge) |
1063 | default_edge->probability = default_prob; | |
584abc98 | 1064 | |
1065 | /* We have altered the probability of the default edge. So the probabilities | |
1066 | of all other edges need to be adjusted so that it sums up to | |
1067 | REG_BR_PROB_BASE. */ | |
1068 | if (base) | |
1069 | { | |
1070 | edge e; | |
1071 | edge_iterator ei; | |
1072 | FOR_EACH_EDGE (e, ei, stmt_bb->succs) | |
f9d4b7f4 | 1073 | e->probability = GCOV_COMPUTE_SCALE (e->probability, base); |
584abc98 | 1074 | } |
5e9ee578 | 1075 | |
584abc98 | 1076 | if (try_with_tablejump) |
1077 | { | |
1078 | bool ok = try_tablejump (index_type, index_expr, minval, range, | |
1079 | table_label, default_label, new_default_prob); | |
1080 | gcc_assert (ok); | |
1081 | } | |
5e9ee578 | 1082 | /* Output the table. */ |
1083 | emit_label (table_label); | |
1084 | ||
1085 | if (CASE_VECTOR_PC_RELATIVE || flag_pic) | |
91f71fa3 | 1086 | emit_jump_table_data (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE, |
1087 | gen_rtx_LABEL_REF (Pmode, | |
1088 | table_label), | |
1089 | gen_rtvec_v (ncases, labelvec), | |
1090 | const0_rtx, const0_rtx)); | |
5e9ee578 | 1091 | else |
91f71fa3 | 1092 | emit_jump_table_data (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE, |
1093 | gen_rtvec_v (ncases, labelvec))); | |
9dfbe515 | 1094 | |
5e9ee578 | 1095 | /* Record no drop-through after the table. */ |
1096 | emit_barrier (); | |
1097 | } | |
32dc5157 | 1098 | |
584abc98 | 1099 | /* Reset the aux field of all outgoing edges of basic block BB. */ |
1100 | ||
1101 | static inline void | |
1102 | reset_out_edges_aux (basic_block bb) | |
1103 | { | |
1104 | edge e; | |
1105 | edge_iterator ei; | |
9af5ce0c | 1106 | FOR_EACH_EDGE (e, ei, bb->succs) |
584abc98 | 1107 | e->aux = (void *)0; |
1108 | } | |
1109 | ||
1110 | /* Compute the number of case labels that correspond to each outgoing edge of | |
1111 | STMT. Record this information in the aux field of the edge. */ | |
1112 | ||
1113 | static inline void | |
1a91d914 | 1114 | compute_cases_per_edge (gswitch *stmt) |
584abc98 | 1115 | { |
1116 | basic_block bb = gimple_bb (stmt); | |
1117 | reset_out_edges_aux (bb); | |
1118 | int ncases = gimple_switch_num_labels (stmt); | |
1119 | for (int i = ncases - 1; i >= 1; --i) | |
1120 | { | |
1121 | tree elt = gimple_switch_label (stmt, i); | |
1122 | tree lab = CASE_LABEL (elt); | |
1123 | basic_block case_bb = label_to_block_fn (cfun, lab); | |
1124 | edge case_edge = find_edge (bb, case_bb); | |
f1a88d1e | 1125 | case_edge->aux = (void *)((intptr_t)(case_edge->aux) + 1); |
584abc98 | 1126 | } |
1127 | } | |
1128 | ||
5e9ee578 | 1129 | /* Terminate a case (Pascal/Ada) or switch (C) statement |
1130 | in which ORIG_INDEX is the expression to be tested. | |
1131 | If ORIG_TYPE is not NULL, it is the original ORIG_INDEX | |
1132 | type as given in the source before any compiler conversions. | |
1133 | Generate the code to test it and jump to the right place. */ | |
32dc5157 | 1134 | |
5e9ee578 | 1135 | void |
1a91d914 | 1136 | expand_case (gswitch *stmt) |
5e9ee578 | 1137 | { |
1138 | tree minval = NULL_TREE, maxval = NULL_TREE, range = NULL_TREE; | |
1139 | rtx default_label = NULL_RTX; | |
1140 | unsigned int count, uniq; | |
49a70175 | 1141 | int i; |
5e9ee578 | 1142 | int ncases = gimple_switch_num_labels (stmt); |
1143 | tree index_expr = gimple_switch_index (stmt); | |
1144 | tree index_type = TREE_TYPE (index_expr); | |
5e9ee578 | 1145 | tree elt; |
584abc98 | 1146 | basic_block bb = gimple_bb (stmt); |
81098a4a | 1147 | |
5e9ee578 | 1148 | /* A list of case labels; it is first built as a list and it may then |
1149 | be rearranged into a nearly balanced binary tree. */ | |
1150 | struct case_node *case_list = 0; | |
81098a4a | 1151 | |
5e9ee578 | 1152 | /* A pool for case nodes. */ |
1153 | alloc_pool case_node_pool; | |
40734805 | 1154 | |
5e9ee578 | 1155 | /* An ERROR_MARK occurs for various reasons including invalid data type. |
1156 | ??? Can this still happen, with GIMPLE and all? */ | |
1157 | if (index_type == error_mark_node) | |
1158 | return; | |
9dfbe515 | 1159 | |
5e9ee578 | 1160 | /* cleanup_tree_cfg removes all SWITCH_EXPR with their index |
1161 | expressions being INTEGER_CST. */ | |
1162 | gcc_assert (TREE_CODE (index_expr) != INTEGER_CST); | |
1163 | ||
1164 | case_node_pool = create_alloc_pool ("struct case_node pool", | |
1165 | sizeof (struct case_node), | |
1166 | 100); | |
9dfbe515 | 1167 | |
5e9ee578 | 1168 | do_pending_stack_adjust (); |
9dfbe515 | 1169 | |
49a70175 | 1170 | /* Find the default case target label. */ |
1171 | default_label = label_rtx (CASE_LABEL (gimple_switch_default_label (stmt))); | |
9af5ce0c | 1172 | edge default_edge = EDGE_SUCC (bb, 0); |
584abc98 | 1173 | int default_prob = default_edge->probability; |
9dfbe515 | 1174 | |
5e9ee578 | 1175 | /* Get upper and lower bounds of case values. */ |
49a70175 | 1176 | elt = gimple_switch_label (stmt, 1); |
5e9ee578 | 1177 | minval = fold_convert (index_type, CASE_LOW (elt)); |
1178 | elt = gimple_switch_label (stmt, ncases - 1); | |
1179 | if (CASE_HIGH (elt)) | |
1180 | maxval = fold_convert (index_type, CASE_HIGH (elt)); | |
1181 | else | |
1182 | maxval = fold_convert (index_type, CASE_LOW (elt)); | |
1183 | ||
1184 | /* Compute span of values. */ | |
1185 | range = fold_build2 (MINUS_EXPR, index_type, maxval, minval); | |
9dfbe515 | 1186 | |
5e9ee578 | 1187 | /* Listify the labels queue and gather some numbers to decide |
1188 | how to expand this switch(). */ | |
1189 | uniq = 0; | |
1190 | count = 0; | |
431205b7 | 1191 | hash_set<tree> seen_labels; |
584abc98 | 1192 | compute_cases_per_edge (stmt); |
1193 | ||
1194 | for (i = ncases - 1; i >= 1; --i) | |
5e9ee578 | 1195 | { |
5e9ee578 | 1196 | elt = gimple_switch_label (stmt, i); |
af68b5a9 | 1197 | tree low = CASE_LOW (elt); |
5e9ee578 | 1198 | gcc_assert (low); |
af68b5a9 | 1199 | tree high = CASE_HIGH (elt); |
5e9ee578 | 1200 | gcc_assert (! high || tree_int_cst_lt (low, high)); |
af68b5a9 | 1201 | tree lab = CASE_LABEL (elt); |
5e9ee578 | 1202 | |
1203 | /* Count the elements. | |
1204 | A range counts double, since it requires two compares. */ | |
1205 | count++; | |
1206 | if (high) | |
1207 | count++; | |
1208 | ||
1209 | /* If we have not seen this label yet, then increase the | |
1210 | number of unique case node targets seen. */ | |
431205b7 | 1211 | if (!seen_labels.add (lab)) |
5e9ee578 | 1212 | uniq++; |
1213 | ||
af68b5a9 | 1214 | /* The bounds on the case range, LOW and HIGH, have to be converted |
1215 | to case's index type TYPE. Note that the original type of the | |
1216 | case index in the source code is usually "lost" during | |
1217 | gimplification due to type promotion, but the case labels retain the | |
1218 | original type. Make sure to drop overflow flags. */ | |
1219 | low = fold_convert (index_type, low); | |
1220 | if (TREE_OVERFLOW (low)) | |
e913b5cd | 1221 | low = wide_int_to_tree (index_type, low); |
af68b5a9 | 1222 | |
5e9ee578 | 1223 | /* The canonical from of a case label in GIMPLE is that a simple case |
1224 | has an empty CASE_HIGH. For the casesi and tablejump expanders, | |
1225 | the back ends want simple cases to have high == low. */ | |
1226 | if (! high) | |
1227 | high = low; | |
af68b5a9 | 1228 | high = fold_convert (index_type, high); |
1229 | if (TREE_OVERFLOW (high)) | |
e913b5cd | 1230 | high = wide_int_to_tree (index_type, high); |
af68b5a9 | 1231 | |
584abc98 | 1232 | basic_block case_bb = label_to_block_fn (cfun, lab); |
1233 | edge case_edge = find_edge (bb, case_bb); | |
1234 | case_list = add_case_node ( | |
1235 | case_list, low, high, lab, | |
f1a88d1e | 1236 | case_edge->probability / (intptr_t)(case_edge->aux), |
584abc98 | 1237 | case_node_pool); |
9dfbe515 | 1238 | } |
584abc98 | 1239 | reset_out_edges_aux (bb); |
5e9ee578 | 1240 | |
1241 | /* cleanup_tree_cfg removes all SWITCH_EXPR with a single | |
1242 | destination, such as one with a default case only. | |
1243 | It also removes cases that are out of range for the switch | |
1244 | type, so we should never get a zero here. */ | |
1245 | gcc_assert (count > 0); | |
1246 | ||
e63d56ca | 1247 | rtx_insn *before_case = get_last_insn (); |
5e9ee578 | 1248 | |
1249 | /* Decide how to expand this switch. | |
1250 | The two options at this point are a dispatch table (casesi or | |
1251 | tablejump) or a decision tree. */ | |
1252 | ||
1253 | if (expand_switch_as_decision_tree_p (range, uniq, count)) | |
1254 | emit_case_decision_tree (index_expr, index_type, | |
584abc98 | 1255 | case_list, default_label, |
1256 | default_prob); | |
5e9ee578 | 1257 | else |
1258 | emit_case_dispatch_table (index_expr, index_type, | |
1259 | case_list, default_label, | |
584abc98 | 1260 | minval, maxval, range, bb); |
5e9ee578 | 1261 | |
af68b5a9 | 1262 | reorder_insns (NEXT_INSN (before_case), get_last_insn (), before_case); |
baf56508 | 1263 | |
9dfbe515 | 1264 | free_temp_slots (); |
4527a0e8 | 1265 | free_alloc_pool (case_node_pool); |
9dfbe515 | 1266 | } |
1267 | ||
af68b5a9 | 1268 | /* Expand the dispatch to a short decrement chain if there are few cases |
1269 | to dispatch to. Likewise if neither casesi nor tablejump is available, | |
1270 | or if flag_jump_tables is set. Otherwise, expand as a casesi or a | |
1271 | tablejump. The index mode is always the mode of integer_type_node. | |
1272 | Trap if no case matches the index. | |
9dfbe515 | 1273 | |
af68b5a9 | 1274 | DISPATCH_INDEX is the index expression to switch on. It should be a |
1275 | memory or register operand. | |
1276 | ||
1277 | DISPATCH_TABLE is a set of case labels. The set should be sorted in | |
1278 | ascending order, be contiguous, starting with value 0, and contain only | |
1279 | single-valued case labels. */ | |
1280 | ||
1281 | void | |
1282 | expand_sjlj_dispatch_table (rtx dispatch_index, | |
f1f41a6c | 1283 | vec<tree> dispatch_table) |
9dfbe515 | 1284 | { |
af68b5a9 | 1285 | tree index_type = integer_type_node; |
3754d046 | 1286 | machine_mode index_mode = TYPE_MODE (index_type); |
af68b5a9 | 1287 | |
f1f41a6c | 1288 | int ncases = dispatch_table.length (); |
af68b5a9 | 1289 | |
1290 | do_pending_stack_adjust (); | |
e63d56ca | 1291 | rtx_insn *before_case = get_last_insn (); |
af68b5a9 | 1292 | |
1293 | /* Expand as a decrement-chain if there are 5 or fewer dispatch | |
1294 | labels. This covers more than 98% of the cases in libjava, | |
1295 | and seems to be a reasonable compromise between the "old way" | |
1296 | of expanding as a decision tree or dispatch table vs. the "new | |
1297 | way" with decrement chain or dispatch table. */ | |
f1f41a6c | 1298 | if (dispatch_table.length () <= 5 |
af68b5a9 | 1299 | || (!HAVE_casesi && !HAVE_tablejump) |
1300 | || !flag_jump_tables) | |
1301 | { | |
1302 | /* Expand the dispatch as a decrement chain: | |
1303 | ||
1304 | "switch(index) {case 0: do_0; case 1: do_1; ...; case N: do_N;}" | |
1305 | ||
1306 | ==> | |
1307 | ||
1308 | if (index == 0) do_0; else index--; | |
1309 | if (index == 0) do_1; else index--; | |
1310 | ... | |
1311 | if (index == 0) do_N; else index--; | |
1312 | ||
1313 | This is more efficient than a dispatch table on most machines. | |
1314 | The last "index--" is redundant but the code is trivially dead | |
1315 | and will be cleaned up by later passes. */ | |
1316 | rtx index = copy_to_mode_reg (index_mode, dispatch_index); | |
1317 | rtx zero = CONST0_RTX (index_mode); | |
1318 | for (int i = 0; i < ncases; i++) | |
1319 | { | |
f1f41a6c | 1320 | tree elt = dispatch_table[i]; |
af68b5a9 | 1321 | rtx lab = label_rtx (CASE_LABEL (elt)); |
584abc98 | 1322 | do_jump_if_equal (index_mode, index, zero, lab, 0, -1); |
af68b5a9 | 1323 | force_expand_binop (index_mode, sub_optab, |
1324 | index, CONST1_RTX (index_mode), | |
1325 | index, 0, OPTAB_DIRECT); | |
1326 | } | |
1327 | } | |
1328 | else | |
1329 | { | |
1330 | /* Similar to expand_case, but much simpler. */ | |
1331 | struct case_node *case_list = 0; | |
1332 | alloc_pool case_node_pool = create_alloc_pool ("struct sjlj_case pool", | |
1333 | sizeof (struct case_node), | |
1334 | ncases); | |
1335 | tree index_expr = make_tree (index_type, dispatch_index); | |
1336 | tree minval = build_int_cst (index_type, 0); | |
f1f41a6c | 1337 | tree maxval = CASE_LOW (dispatch_table.last ()); |
af68b5a9 | 1338 | tree range = maxval; |
79f6a8ed | 1339 | rtx_code_label *default_label = gen_label_rtx (); |
af68b5a9 | 1340 | |
ad49e9c0 | 1341 | for (int i = ncases - 1; i >= 0; --i) |
af68b5a9 | 1342 | { |
f1f41a6c | 1343 | tree elt = dispatch_table[i]; |
af68b5a9 | 1344 | tree low = CASE_LOW (elt); |
1345 | tree lab = CASE_LABEL (elt); | |
584abc98 | 1346 | case_list = add_case_node (case_list, low, low, lab, 0, case_node_pool); |
af68b5a9 | 1347 | } |
1348 | ||
1349 | emit_case_dispatch_table (index_expr, index_type, | |
1350 | case_list, default_label, | |
e065d0bc | 1351 | minval, maxval, range, |
1352 | BLOCK_FOR_INSN (before_case)); | |
af68b5a9 | 1353 | emit_label (default_label); |
1354 | free_alloc_pool (case_node_pool); | |
1355 | } | |
1356 | ||
1357 | /* Dispatching something not handled? Trap! */ | |
1358 | expand_builtin_trap (); | |
1359 | ||
1360 | reorder_insns (NEXT_INSN (before_case), get_last_insn (), before_case); | |
1361 | ||
1362 | free_temp_slots (); | |
9dfbe515 | 1363 | } |
af68b5a9 | 1364 | |
9dfbe515 | 1365 | \f |
9dfbe515 | 1366 | /* Take an ordered list of case nodes |
1367 | and transform them into a near optimal binary tree, | |
4bbea254 | 1368 | on the assumption that any target code selection value is as |
9dfbe515 | 1369 | likely as any other. |
1370 | ||
1371 | The transformation is performed by splitting the ordered | |
1372 | list into two equal sections plus a pivot. The parts are | |
1373 | then attached to the pivot as left and right branches. Each | |
3398e91d | 1374 | branch is then transformed recursively. */ |
9dfbe515 | 1375 | |
1376 | static void | |
60b8c5b3 | 1377 | balance_case_nodes (case_node_ptr *head, case_node_ptr parent) |
9dfbe515 | 1378 | { |
19cb6b50 | 1379 | case_node_ptr np; |
9dfbe515 | 1380 | |
1381 | np = *head; | |
1382 | if (np) | |
1383 | { | |
9dfbe515 | 1384 | int i = 0; |
1385 | int ranges = 0; | |
19cb6b50 | 1386 | case_node_ptr *npp; |
9dfbe515 | 1387 | case_node_ptr left; |
1388 | ||
1389 | /* Count the number of entries on branch. Also count the ranges. */ | |
1390 | ||
1391 | while (np) | |
1392 | { | |
1393 | if (!tree_int_cst_equal (np->low, np->high)) | |
1c391fd0 | 1394 | ranges++; |
9dfbe515 | 1395 | |
1396 | i++; | |
1397 | np = np->right; | |
1398 | } | |
1399 | ||
1400 | if (i > 2) | |
1401 | { | |
1402 | /* Split this list if it is long enough for that to help. */ | |
1403 | npp = head; | |
1404 | left = *npp; | |
1c391fd0 | 1405 | |
9dfbe515 | 1406 | /* If there are just three nodes, split at the middle one. */ |
1c391fd0 | 1407 | if (i == 3) |
9dfbe515 | 1408 | npp = &(*npp)->right; |
1409 | else | |
1410 | { | |
1411 | /* Find the place in the list that bisects the list's total cost, | |
1412 | where ranges count as 2. | |
1413 | Here I gets half the total cost. */ | |
1414 | i = (i + ranges + 1) / 2; | |
1415 | while (1) | |
1416 | { | |
1417 | /* Skip nodes while their cost does not reach that amount. */ | |
1418 | if (!tree_int_cst_equal ((*npp)->low, (*npp)->high)) | |
1419 | i--; | |
1420 | i--; | |
1421 | if (i <= 0) | |
1422 | break; | |
1423 | npp = &(*npp)->right; | |
1424 | } | |
1425 | } | |
1426 | *head = np = *npp; | |
1427 | *npp = 0; | |
1428 | np->parent = parent; | |
1429 | np->left = left; | |
1430 | ||
1431 | /* Optimize each of the two split parts. */ | |
1432 | balance_case_nodes (&np->left, np); | |
1433 | balance_case_nodes (&np->right, np); | |
584abc98 | 1434 | np->subtree_prob = np->prob; |
1435 | np->subtree_prob += np->left->subtree_prob; | |
1436 | np->subtree_prob += np->right->subtree_prob; | |
9dfbe515 | 1437 | } |
1438 | else | |
1439 | { | |
1440 | /* Else leave this branch as one level, | |
1441 | but fill in `parent' fields. */ | |
1442 | np = *head; | |
1443 | np->parent = parent; | |
584abc98 | 1444 | np->subtree_prob = np->prob; |
9dfbe515 | 1445 | for (; np->right; np = np->right) |
584abc98 | 1446 | { |
1447 | np->right->parent = np; | |
1448 | (*head)->subtree_prob += np->right->subtree_prob; | |
1449 | } | |
9dfbe515 | 1450 | } |
1451 | } | |
1452 | } | |
1453 | \f | |
1454 | /* Search the parent sections of the case node tree | |
1455 | to see if a test for the lower bound of NODE would be redundant. | |
1456 | INDEX_TYPE is the type of the index expression. | |
1457 | ||
1458 | The instructions to generate the case decision tree are | |
1459 | output in the same order as nodes are processed so it is | |
1460 | known that if a parent node checks the range of the current | |
1461 | node minus one that the current node is bounded at its lower | |
1462 | span. Thus the test would be redundant. */ | |
1463 | ||
1464 | static int | |
60b8c5b3 | 1465 | node_has_low_bound (case_node_ptr node, tree index_type) |
9dfbe515 | 1466 | { |
1467 | tree low_minus_one; | |
1468 | case_node_ptr pnode; | |
1469 | ||
1470 | /* If the lower bound of this node is the lowest value in the index type, | |
1471 | we need not test it. */ | |
1472 | ||
1473 | if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type))) | |
1474 | return 1; | |
1475 | ||
1476 | /* If this node has a left branch, the value at the left must be less | |
1477 | than that at this node, so it cannot be bounded at the bottom and | |
1478 | we need not bother testing any further. */ | |
1479 | ||
1480 | if (node->left) | |
1481 | return 0; | |
1482 | ||
faa43f85 | 1483 | low_minus_one = fold_build2 (MINUS_EXPR, TREE_TYPE (node->low), |
b4bd9527 | 1484 | node->low, |
1485 | build_int_cst (TREE_TYPE (node->low), 1)); | |
9dfbe515 | 1486 | |
1487 | /* If the subtraction above overflowed, we can't verify anything. | |
1488 | Otherwise, look for a parent that tests our value - 1. */ | |
1489 | ||
1490 | if (! tree_int_cst_lt (low_minus_one, node->low)) | |
1491 | return 0; | |
1492 | ||
1493 | for (pnode = node->parent; pnode; pnode = pnode->parent) | |
1494 | if (tree_int_cst_equal (low_minus_one, pnode->high)) | |
1495 | return 1; | |
1496 | ||
1497 | return 0; | |
1498 | } | |
1499 | ||
1500 | /* Search the parent sections of the case node tree | |
1501 | to see if a test for the upper bound of NODE would be redundant. | |
1502 | INDEX_TYPE is the type of the index expression. | |
1503 | ||
1504 | The instructions to generate the case decision tree are | |
1505 | output in the same order as nodes are processed so it is | |
1506 | known that if a parent node checks the range of the current | |
1507 | node plus one that the current node is bounded at its upper | |
1508 | span. Thus the test would be redundant. */ | |
1509 | ||
1510 | static int | |
60b8c5b3 | 1511 | node_has_high_bound (case_node_ptr node, tree index_type) |
9dfbe515 | 1512 | { |
1513 | tree high_plus_one; | |
1514 | case_node_ptr pnode; | |
1515 | ||
f52483b5 | 1516 | /* If there is no upper bound, obviously no test is needed. */ |
1517 | ||
1518 | if (TYPE_MAX_VALUE (index_type) == NULL) | |
1519 | return 1; | |
1520 | ||
9dfbe515 | 1521 | /* If the upper bound of this node is the highest value in the type |
1522 | of the index expression, we need not test against it. */ | |
1523 | ||
1524 | if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type))) | |
1525 | return 1; | |
1526 | ||
1527 | /* If this node has a right branch, the value at the right must be greater | |
1528 | than that at this node, so it cannot be bounded at the top and | |
1529 | we need not bother testing any further. */ | |
1530 | ||
1531 | if (node->right) | |
1532 | return 0; | |
1533 | ||
faa43f85 | 1534 | high_plus_one = fold_build2 (PLUS_EXPR, TREE_TYPE (node->high), |
b4bd9527 | 1535 | node->high, |
1536 | build_int_cst (TREE_TYPE (node->high), 1)); | |
9dfbe515 | 1537 | |
1538 | /* If the addition above overflowed, we can't verify anything. | |
1539 | Otherwise, look for a parent that tests our value + 1. */ | |
1540 | ||
1541 | if (! tree_int_cst_lt (node->high, high_plus_one)) | |
1542 | return 0; | |
1543 | ||
1544 | for (pnode = node->parent; pnode; pnode = pnode->parent) | |
1545 | if (tree_int_cst_equal (high_plus_one, pnode->low)) | |
1546 | return 1; | |
1547 | ||
1548 | return 0; | |
1549 | } | |
1550 | ||
1551 | /* Search the parent sections of the | |
1552 | case node tree to see if both tests for the upper and lower | |
1553 | bounds of NODE would be redundant. */ | |
1554 | ||
1555 | static int | |
60b8c5b3 | 1556 | node_is_bounded (case_node_ptr node, tree index_type) |
9dfbe515 | 1557 | { |
1558 | return (node_has_low_bound (node, index_type) | |
1559 | && node_has_high_bound (node, index_type)); | |
1560 | } | |
9dfbe515 | 1561 | \f |
584abc98 | 1562 | |
9dfbe515 | 1563 | /* Emit step-by-step code to select a case for the value of INDEX. |
1564 | The thus generated decision tree follows the form of the | |
1565 | case-node binary tree NODE, whose nodes represent test conditions. | |
1566 | INDEX_TYPE is the type of the index of the switch. | |
1567 | ||
1568 | Care is taken to prune redundant tests from the decision tree | |
1569 | by detecting any boundary conditions already checked by | |
1570 | emitted rtx. (See node_has_high_bound, node_has_low_bound | |
1571 | and node_is_bounded, above.) | |
1572 | ||
1573 | Where the test conditions can be shown to be redundant we emit | |
1574 | an unconditional jump to the target code. As a further | |
1575 | optimization, the subordinates of a tree node are examined to | |
1576 | check for bounded nodes. In this case conditional and/or | |
1577 | unconditional jumps as a result of the boundary check for the | |
1578 | current node are arranged to target the subordinates associated | |
3398e91d | 1579 | code for out of bound conditions on the current node. |
9dfbe515 | 1580 | |
eb2f80f3 | 1581 | We can assume that when control reaches the code generated here, |
9dfbe515 | 1582 | the index value has already been compared with the parents |
1583 | of this node, and determined to be on the same side of each parent | |
1584 | as this node is. Thus, if this node tests for the value 51, | |
1585 | and a parent tested for 52, we don't need to consider | |
1586 | the possibility of a value greater than 51. If another parent | |
1587 | tests for the value 50, then this node need not test anything. */ | |
1588 | ||
1589 | static void | |
60b8c5b3 | 1590 | emit_case_nodes (rtx index, case_node_ptr node, rtx default_label, |
584abc98 | 1591 | int default_prob, tree index_type) |
9dfbe515 | 1592 | { |
1593 | /* If INDEX has an unsigned type, we must make unsigned branches. */ | |
78a8ed03 | 1594 | int unsignedp = TYPE_UNSIGNED (index_type); |
584abc98 | 1595 | int probability; |
1596 | int prob = node->prob, subtree_prob = node->subtree_prob; | |
3754d046 | 1597 | machine_mode mode = GET_MODE (index); |
1598 | machine_mode imode = TYPE_MODE (index_type); | |
9dfbe515 | 1599 | |
a4047043 | 1600 | /* Handle indices detected as constant during RTL expansion. */ |
1601 | if (mode == VOIDmode) | |
1602 | mode = imode; | |
1603 | ||
9dfbe515 | 1604 | /* See if our parents have already tested everything for us. |
1605 | If they have, emit an unconditional jump for this node. */ | |
1606 | if (node_is_bounded (node, index_type)) | |
1607 | emit_jump (label_rtx (node->code_label)); | |
1608 | ||
1609 | else if (tree_int_cst_equal (node->low, node->high)) | |
1610 | { | |
584abc98 | 1611 | probability = conditional_probability (prob, subtree_prob + default_prob); |
9dfbe515 | 1612 | /* Node is single valued. First see if the index expression matches |
a92771b8 | 1613 | this node and then check our children, if any. */ |
85afca2d | 1614 | do_jump_if_equal (mode, index, |
213b27c9 | 1615 | convert_modes (mode, imode, |
8ec3c5c2 | 1616 | expand_normal (node->low), |
213b27c9 | 1617 | unsignedp), |
584abc98 | 1618 | label_rtx (node->code_label), unsignedp, probability); |
1619 | /* Since this case is taken at this point, reduce its weight from | |
1620 | subtree_weight. */ | |
1621 | subtree_prob -= prob; | |
9dfbe515 | 1622 | if (node->right != 0 && node->left != 0) |
1623 | { | |
1624 | /* This node has children on both sides. | |
1625 | Dispatch to one side or the other | |
1626 | by comparing the index value with this node's value. | |
1627 | If one subtree is bounded, check that one first, | |
1628 | so we can avoid real branches in the tree. */ | |
1629 | ||
1630 | if (node_is_bounded (node->right, index_type)) | |
1631 | { | |
584abc98 | 1632 | probability = conditional_probability ( |
1633 | node->right->prob, | |
1634 | subtree_prob + default_prob); | |
67610d42 | 1635 | emit_cmp_and_jump_insns (index, |
213b27c9 | 1636 | convert_modes |
1637 | (mode, imode, | |
8ec3c5c2 | 1638 | expand_normal (node->high), |
213b27c9 | 1639 | unsignedp), |
7e69f45b | 1640 | GT, NULL_RTX, mode, unsignedp, |
584abc98 | 1641 | label_rtx (node->right->code_label), |
1642 | probability); | |
1643 | emit_case_nodes (index, node->left, default_label, default_prob, | |
1644 | index_type); | |
9dfbe515 | 1645 | } |
1646 | ||
1647 | else if (node_is_bounded (node->left, index_type)) | |
1648 | { | |
584abc98 | 1649 | probability = conditional_probability ( |
1650 | node->left->prob, | |
1651 | subtree_prob + default_prob); | |
67610d42 | 1652 | emit_cmp_and_jump_insns (index, |
213b27c9 | 1653 | convert_modes |
1654 | (mode, imode, | |
8ec3c5c2 | 1655 | expand_normal (node->high), |
213b27c9 | 1656 | unsignedp), |
7e69f45b | 1657 | LT, NULL_RTX, mode, unsignedp, |
584abc98 | 1658 | label_rtx (node->left->code_label), |
1659 | probability); | |
1660 | emit_case_nodes (index, node->right, default_label, default_prob, index_type); | |
9dfbe515 | 1661 | } |
1662 | ||
84e90d04 | 1663 | /* If both children are single-valued cases with no |
1664 | children, finish up all the work. This way, we can save | |
1665 | one ordered comparison. */ | |
1666 | else if (tree_int_cst_equal (node->right->low, node->right->high) | |
1667 | && node->right->left == 0 | |
1668 | && node->right->right == 0 | |
1669 | && tree_int_cst_equal (node->left->low, node->left->high) | |
1670 | && node->left->left == 0 | |
1671 | && node->left->right == 0) | |
1672 | { | |
1673 | /* Neither node is bounded. First distinguish the two sides; | |
1674 | then emit the code for one side at a time. */ | |
1675 | ||
1676 | /* See if the value matches what the right hand side | |
1677 | wants. */ | |
584abc98 | 1678 | probability = conditional_probability ( |
1679 | node->right->prob, | |
1680 | subtree_prob + default_prob); | |
85afca2d | 1681 | do_jump_if_equal (mode, index, |
84e90d04 | 1682 | convert_modes (mode, imode, |
8ec3c5c2 | 1683 | expand_normal (node->right->low), |
84e90d04 | 1684 | unsignedp), |
1685 | label_rtx (node->right->code_label), | |
584abc98 | 1686 | unsignedp, probability); |
84e90d04 | 1687 | |
1688 | /* See if the value matches what the left hand side | |
1689 | wants. */ | |
584abc98 | 1690 | probability = conditional_probability ( |
1691 | node->left->prob, | |
1692 | subtree_prob + default_prob); | |
85afca2d | 1693 | do_jump_if_equal (mode, index, |
84e90d04 | 1694 | convert_modes (mode, imode, |
8ec3c5c2 | 1695 | expand_normal (node->left->low), |
84e90d04 | 1696 | unsignedp), |
1697 | label_rtx (node->left->code_label), | |
584abc98 | 1698 | unsignedp, probability); |
84e90d04 | 1699 | } |
1700 | ||
9dfbe515 | 1701 | else |
1702 | { | |
1703 | /* Neither node is bounded. First distinguish the two sides; | |
1704 | then emit the code for one side at a time. */ | |
1705 | ||
e60a6f7b | 1706 | tree test_label |
5169661d | 1707 | = build_decl (curr_insn_location (), |
e60a6f7b | 1708 | LABEL_DECL, NULL_TREE, NULL_TREE); |
9dfbe515 | 1709 | |
584abc98 | 1710 | /* The default label could be reached either through the right |
1711 | subtree or the left subtree. Divide the probability | |
1712 | equally. */ | |
1713 | probability = conditional_probability ( | |
1714 | node->right->subtree_prob + default_prob/2, | |
1715 | subtree_prob + default_prob); | |
9dfbe515 | 1716 | /* See if the value is on the right. */ |
67610d42 | 1717 | emit_cmp_and_jump_insns (index, |
213b27c9 | 1718 | convert_modes |
1719 | (mode, imode, | |
8ec3c5c2 | 1720 | expand_normal (node->high), |
213b27c9 | 1721 | unsignedp), |
7e69f45b | 1722 | GT, NULL_RTX, mode, unsignedp, |
584abc98 | 1723 | label_rtx (test_label), |
1724 | probability); | |
1725 | default_prob /= 2; | |
9dfbe515 | 1726 | |
1727 | /* Value must be on the left. | |
1728 | Handle the left-hand subtree. */ | |
584abc98 | 1729 | emit_case_nodes (index, node->left, default_label, default_prob, index_type); |
9dfbe515 | 1730 | /* If left-hand subtree does nothing, |
1731 | go to default. */ | |
72c30859 | 1732 | if (default_label) |
1733 | emit_jump (default_label); | |
9dfbe515 | 1734 | |
1735 | /* Code branches here for the right-hand subtree. */ | |
1736 | expand_label (test_label); | |
584abc98 | 1737 | emit_case_nodes (index, node->right, default_label, default_prob, index_type); |
9dfbe515 | 1738 | } |
1739 | } | |
1740 | ||
1741 | else if (node->right != 0 && node->left == 0) | |
1742 | { | |
a33d8949 | 1743 | /* Here we have a right child but no left so we issue a conditional |
9dfbe515 | 1744 | branch to default and process the right child. |
1745 | ||
a33d8949 | 1746 | Omit the conditional branch to default if the right child |
1747 | does not have any children and is single valued; it would | |
1748 | cost too much space to save so little time. */ | |
9dfbe515 | 1749 | |
b60acb0b | 1750 | if (node->right->right || node->right->left |
9dfbe515 | 1751 | || !tree_int_cst_equal (node->right->low, node->right->high)) |
1752 | { | |
1753 | if (!node_has_low_bound (node, index_type)) | |
1754 | { | |
584abc98 | 1755 | probability = conditional_probability ( |
1756 | default_prob/2, | |
1757 | subtree_prob + default_prob); | |
67610d42 | 1758 | emit_cmp_and_jump_insns (index, |
213b27c9 | 1759 | convert_modes |
1760 | (mode, imode, | |
8ec3c5c2 | 1761 | expand_normal (node->high), |
213b27c9 | 1762 | unsignedp), |
7e69f45b | 1763 | LT, NULL_RTX, mode, unsignedp, |
584abc98 | 1764 | default_label, |
1765 | probability); | |
1766 | default_prob /= 2; | |
9dfbe515 | 1767 | } |
1768 | ||
584abc98 | 1769 | emit_case_nodes (index, node->right, default_label, default_prob, index_type); |
9dfbe515 | 1770 | } |
1771 | else | |
584abc98 | 1772 | { |
1773 | probability = conditional_probability ( | |
1774 | node->right->subtree_prob, | |
1775 | subtree_prob + default_prob); | |
1776 | /* We cannot process node->right normally | |
1777 | since we haven't ruled out the numbers less than | |
1778 | this node's value. So handle node->right explicitly. */ | |
1779 | do_jump_if_equal (mode, index, | |
1780 | convert_modes | |
1781 | (mode, imode, | |
1782 | expand_normal (node->right->low), | |
1783 | unsignedp), | |
1784 | label_rtx (node->right->code_label), unsignedp, probability); | |
1785 | } | |
1786 | } | |
9dfbe515 | 1787 | |
1788 | else if (node->right == 0 && node->left != 0) | |
1789 | { | |
1790 | /* Just one subtree, on the left. */ | |
67610d42 | 1791 | if (node->left->left || node->left->right |
9dfbe515 | 1792 | || !tree_int_cst_equal (node->left->low, node->left->high)) |
1793 | { | |
1794 | if (!node_has_high_bound (node, index_type)) | |
1795 | { | |
584abc98 | 1796 | probability = conditional_probability ( |
1797 | default_prob/2, | |
1798 | subtree_prob + default_prob); | |
213b27c9 | 1799 | emit_cmp_and_jump_insns (index, |
1800 | convert_modes | |
1801 | (mode, imode, | |
8ec3c5c2 | 1802 | expand_normal (node->high), |
213b27c9 | 1803 | unsignedp), |
7e69f45b | 1804 | GT, NULL_RTX, mode, unsignedp, |
584abc98 | 1805 | default_label, |
1806 | probability); | |
1807 | default_prob /= 2; | |
9dfbe515 | 1808 | } |
1809 | ||
584abc98 | 1810 | emit_case_nodes (index, node->left, default_label, |
1811 | default_prob, index_type); | |
9dfbe515 | 1812 | } |
1813 | else | |
584abc98 | 1814 | { |
1815 | probability = conditional_probability ( | |
1816 | node->left->subtree_prob, | |
1817 | subtree_prob + default_prob); | |
1818 | /* We cannot process node->left normally | |
1819 | since we haven't ruled out the numbers less than | |
1820 | this node's value. So handle node->left explicitly. */ | |
1821 | do_jump_if_equal (mode, index, | |
1822 | convert_modes | |
1823 | (mode, imode, | |
1824 | expand_normal (node->left->low), | |
1825 | unsignedp), | |
1826 | label_rtx (node->left->code_label), unsignedp, probability); | |
1827 | } | |
9dfbe515 | 1828 | } |
1829 | } | |
1830 | else | |
1831 | { | |
1832 | /* Node is a range. These cases are very similar to those for a single | |
1833 | value, except that we do not start by testing whether this node | |
1834 | is the one to branch to. */ | |
1835 | ||
1836 | if (node->right != 0 && node->left != 0) | |
1837 | { | |
1838 | /* Node has subtrees on both sides. | |
1839 | If the right-hand subtree is bounded, | |
1840 | test for it first, since we can go straight there. | |
1841 | Otherwise, we need to make a branch in the control structure, | |
1842 | then handle the two subtrees. */ | |
1843 | tree test_label = 0; | |
1844 | ||
9dfbe515 | 1845 | if (node_is_bounded (node->right, index_type)) |
584abc98 | 1846 | { |
1847 | /* Right hand node is fully bounded so we can eliminate any | |
1848 | testing and branch directly to the target code. */ | |
1849 | probability = conditional_probability ( | |
1850 | node->right->subtree_prob, | |
1851 | subtree_prob + default_prob); | |
1852 | emit_cmp_and_jump_insns (index, | |
1853 | convert_modes | |
1854 | (mode, imode, | |
1855 | expand_normal (node->high), | |
1856 | unsignedp), | |
1857 | GT, NULL_RTX, mode, unsignedp, | |
1858 | label_rtx (node->right->code_label), | |
1859 | probability); | |
1860 | } | |
9dfbe515 | 1861 | else |
1862 | { | |
1863 | /* Right hand node requires testing. | |
1864 | Branch to a label where we will handle it later. */ | |
1865 | ||
5169661d | 1866 | test_label = build_decl (curr_insn_location (), |
e60a6f7b | 1867 | LABEL_DECL, NULL_TREE, NULL_TREE); |
584abc98 | 1868 | probability = conditional_probability ( |
1869 | node->right->subtree_prob + default_prob/2, | |
1870 | subtree_prob + default_prob); | |
67610d42 | 1871 | emit_cmp_and_jump_insns (index, |
213b27c9 | 1872 | convert_modes |
1873 | (mode, imode, | |
8ec3c5c2 | 1874 | expand_normal (node->high), |
213b27c9 | 1875 | unsignedp), |
7e69f45b | 1876 | GT, NULL_RTX, mode, unsignedp, |
584abc98 | 1877 | label_rtx (test_label), |
1878 | probability); | |
1879 | default_prob /= 2; | |
9dfbe515 | 1880 | } |
1881 | ||
1882 | /* Value belongs to this node or to the left-hand subtree. */ | |
1883 | ||
584abc98 | 1884 | probability = conditional_probability ( |
1885 | prob, | |
1886 | subtree_prob + default_prob); | |
213b27c9 | 1887 | emit_cmp_and_jump_insns (index, |
1888 | convert_modes | |
1889 | (mode, imode, | |
8ec3c5c2 | 1890 | expand_normal (node->low), |
213b27c9 | 1891 | unsignedp), |
7e69f45b | 1892 | GE, NULL_RTX, mode, unsignedp, |
584abc98 | 1893 | label_rtx (node->code_label), |
1894 | probability); | |
9dfbe515 | 1895 | |
1896 | /* Handle the left-hand subtree. */ | |
584abc98 | 1897 | emit_case_nodes (index, node->left, default_label, default_prob, index_type); |
9dfbe515 | 1898 | |
1899 | /* If right node had to be handled later, do that now. */ | |
1900 | ||
1901 | if (test_label) | |
1902 | { | |
1903 | /* If the left-hand subtree fell through, | |
1904 | don't let it fall into the right-hand subtree. */ | |
72c30859 | 1905 | if (default_label) |
1906 | emit_jump (default_label); | |
9dfbe515 | 1907 | |
1908 | expand_label (test_label); | |
584abc98 | 1909 | emit_case_nodes (index, node->right, default_label, default_prob, index_type); |
9dfbe515 | 1910 | } |
1911 | } | |
1912 | ||
1913 | else if (node->right != 0 && node->left == 0) | |
1914 | { | |
1915 | /* Deal with values to the left of this node, | |
1916 | if they are possible. */ | |
1917 | if (!node_has_low_bound (node, index_type)) | |
1918 | { | |
584abc98 | 1919 | probability = conditional_probability ( |
1920 | default_prob/2, | |
1921 | subtree_prob + default_prob); | |
67610d42 | 1922 | emit_cmp_and_jump_insns (index, |
213b27c9 | 1923 | convert_modes |
1924 | (mode, imode, | |
8ec3c5c2 | 1925 | expand_normal (node->low), |
213b27c9 | 1926 | unsignedp), |
7e69f45b | 1927 | LT, NULL_RTX, mode, unsignedp, |
584abc98 | 1928 | default_label, |
1929 | probability); | |
1930 | default_prob /= 2; | |
9dfbe515 | 1931 | } |
1932 | ||
1933 | /* Value belongs to this node or to the right-hand subtree. */ | |
1934 | ||
584abc98 | 1935 | probability = conditional_probability ( |
1936 | prob, | |
1937 | subtree_prob + default_prob); | |
213b27c9 | 1938 | emit_cmp_and_jump_insns (index, |
1939 | convert_modes | |
1940 | (mode, imode, | |
8ec3c5c2 | 1941 | expand_normal (node->high), |
213b27c9 | 1942 | unsignedp), |
7e69f45b | 1943 | LE, NULL_RTX, mode, unsignedp, |
584abc98 | 1944 | label_rtx (node->code_label), |
1945 | probability); | |
9dfbe515 | 1946 | |
584abc98 | 1947 | emit_case_nodes (index, node->right, default_label, default_prob, index_type); |
9dfbe515 | 1948 | } |
1949 | ||
1950 | else if (node->right == 0 && node->left != 0) | |
1951 | { | |
1952 | /* Deal with values to the right of this node, | |
1953 | if they are possible. */ | |
1954 | if (!node_has_high_bound (node, index_type)) | |
1955 | { | |
584abc98 | 1956 | probability = conditional_probability ( |
1957 | default_prob/2, | |
1958 | subtree_prob + default_prob); | |
67610d42 | 1959 | emit_cmp_and_jump_insns (index, |
213b27c9 | 1960 | convert_modes |
1961 | (mode, imode, | |
8ec3c5c2 | 1962 | expand_normal (node->high), |
213b27c9 | 1963 | unsignedp), |
7e69f45b | 1964 | GT, NULL_RTX, mode, unsignedp, |
584abc98 | 1965 | default_label, |
1966 | probability); | |
1967 | default_prob /= 2; | |
9dfbe515 | 1968 | } |
1969 | ||
1970 | /* Value belongs to this node or to the left-hand subtree. */ | |
1971 | ||
584abc98 | 1972 | probability = conditional_probability ( |
1973 | prob, | |
1974 | subtree_prob + default_prob); | |
67610d42 | 1975 | emit_cmp_and_jump_insns (index, |
213b27c9 | 1976 | convert_modes |
1977 | (mode, imode, | |
8ec3c5c2 | 1978 | expand_normal (node->low), |
213b27c9 | 1979 | unsignedp), |
7e69f45b | 1980 | GE, NULL_RTX, mode, unsignedp, |
584abc98 | 1981 | label_rtx (node->code_label), |
1982 | probability); | |
9dfbe515 | 1983 | |
584abc98 | 1984 | emit_case_nodes (index, node->left, default_label, default_prob, index_type); |
9dfbe515 | 1985 | } |
1986 | ||
1987 | else | |
1988 | { | |
1989 | /* Node has no children so we check low and high bounds to remove | |
1990 | redundant tests. Only one of the bounds can exist, | |
1991 | since otherwise this node is bounded--a case tested already. */ | |
f6664fee | 1992 | int high_bound = node_has_high_bound (node, index_type); |
1993 | int low_bound = node_has_low_bound (node, index_type); | |
9dfbe515 | 1994 | |
f6664fee | 1995 | if (!high_bound && low_bound) |
9dfbe515 | 1996 | { |
584abc98 | 1997 | probability = conditional_probability ( |
1998 | default_prob, | |
1999 | subtree_prob + default_prob); | |
67610d42 | 2000 | emit_cmp_and_jump_insns (index, |
213b27c9 | 2001 | convert_modes |
2002 | (mode, imode, | |
8ec3c5c2 | 2003 | expand_normal (node->high), |
213b27c9 | 2004 | unsignedp), |
7e69f45b | 2005 | GT, NULL_RTX, mode, unsignedp, |
584abc98 | 2006 | default_label, |
2007 | probability); | |
9dfbe515 | 2008 | } |
2009 | ||
f6664fee | 2010 | else if (!low_bound && high_bound) |
9dfbe515 | 2011 | { |
584abc98 | 2012 | probability = conditional_probability ( |
2013 | default_prob, | |
2014 | subtree_prob + default_prob); | |
67610d42 | 2015 | emit_cmp_and_jump_insns (index, |
213b27c9 | 2016 | convert_modes |
2017 | (mode, imode, | |
8ec3c5c2 | 2018 | expand_normal (node->low), |
213b27c9 | 2019 | unsignedp), |
7e69f45b | 2020 | LT, NULL_RTX, mode, unsignedp, |
584abc98 | 2021 | default_label, |
2022 | probability); | |
9dfbe515 | 2023 | } |
f6664fee | 2024 | else if (!low_bound && !high_bound) |
2025 | { | |
afa9f587 | 2026 | /* Widen LOW and HIGH to the same width as INDEX. */ |
dc24ddbd | 2027 | tree type = lang_hooks.types.type_for_mode (mode, unsignedp); |
afa9f587 | 2028 | tree low = build1 (CONVERT_EXPR, type, node->low); |
2029 | tree high = build1 (CONVERT_EXPR, type, node->high); | |
ad99e708 | 2030 | rtx low_rtx, new_index, new_bound; |
afa9f587 | 2031 | |
2032 | /* Instead of doing two branches, emit one unsigned branch for | |
2033 | (index-low) > (high-low). */ | |
8ec3c5c2 | 2034 | low_rtx = expand_expr (low, NULL_RTX, mode, EXPAND_NORMAL); |
ad99e708 | 2035 | new_index = expand_simple_binop (mode, MINUS, index, low_rtx, |
2036 | NULL_RTX, unsignedp, | |
2037 | OPTAB_WIDEN); | |
faa43f85 | 2038 | new_bound = expand_expr (fold_build2 (MINUS_EXPR, type, |
2039 | high, low), | |
8ec3c5c2 | 2040 | NULL_RTX, mode, EXPAND_NORMAL); |
40734805 | 2041 | |
584abc98 | 2042 | probability = conditional_probability ( |
2043 | default_prob, | |
2044 | subtree_prob + default_prob); | |
afa9f587 | 2045 | emit_cmp_and_jump_insns (new_index, new_bound, GT, NULL_RTX, |
584abc98 | 2046 | mode, 1, default_label, probability); |
f6664fee | 2047 | } |
9dfbe515 | 2048 | |
2049 | emit_jump (label_rtx (node->code_label)); | |
2050 | } | |
2051 | } | |
2052 | } |