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