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28d81abb | 1 | /* Expands front end tree to back end RTL for GNU C-Compiler |
5eb94e4e | 2 | Copyright (C) 1987, 1988, 1989, 1992, 1993 Free Software Foundation, Inc. |
28d81abb RK |
3 | |
4 | This file is part of GNU CC. | |
5 | ||
6 | GNU CC is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 2, or (at your option) | |
9 | any later version. | |
10 | ||
11 | GNU CC is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with GNU CC; see the file COPYING. If not, write to | |
18 | the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
19 | ||
20 | ||
21 | /* This file handles the generation of rtl code from tree structure | |
22 | above the level of expressions, using subroutines in exp*.c and emit-rtl.c. | |
23 | It also creates the rtl expressions for parameters and auto variables | |
24 | and has full responsibility for allocating stack slots. | |
25 | ||
26 | The functions whose names start with `expand_' are called by the | |
27 | parser to generate RTL instructions for various kinds of constructs. | |
28 | ||
29 | Some control and binding constructs require calling several such | |
30 | functions at different times. For example, a simple if-then | |
31 | is expanded by calling `expand_start_cond' (with the condition-expression | |
32 | as argument) before parsing the then-clause and calling `expand_end_cond' | |
33 | after parsing the then-clause. */ | |
34 | ||
35 | #include "config.h" | |
36 | ||
37 | #include <stdio.h> | |
38 | #include <ctype.h> | |
39 | ||
40 | #include "rtl.h" | |
41 | #include "tree.h" | |
42 | #include "flags.h" | |
43 | #include "function.h" | |
44 | #include "insn-flags.h" | |
45 | #include "insn-config.h" | |
46 | #include "insn-codes.h" | |
47 | #include "expr.h" | |
48 | #include "hard-reg-set.h" | |
49 | #include "obstack.h" | |
50 | #include "loop.h" | |
51 | #include "recog.h" | |
ca695ac9 JB |
52 | #include "machmode.h" |
53 | ||
54 | #include "bytecode.h" | |
55 | #include "bc-typecd.h" | |
56 | #include "bc-opcode.h" | |
57 | #include "bc-optab.h" | |
58 | #include "bc-emit.h" | |
28d81abb RK |
59 | |
60 | #define obstack_chunk_alloc xmalloc | |
61 | #define obstack_chunk_free free | |
62 | struct obstack stmt_obstack; | |
63 | ||
28d81abb RK |
64 | /* Filename and line number of last line-number note, |
65 | whether we actually emitted it or not. */ | |
66 | char *emit_filename; | |
67 | int emit_lineno; | |
68 | ||
69 | /* Nonzero if within a ({...}) grouping, in which case we must | |
70 | always compute a value for each expr-stmt in case it is the last one. */ | |
71 | ||
72 | int expr_stmts_for_value; | |
73 | ||
74 | /* Each time we expand an expression-statement, | |
75 | record the expr's type and its RTL value here. */ | |
76 | ||
77 | static tree last_expr_type; | |
78 | static rtx last_expr_value; | |
79 | ||
7629c936 RS |
80 | /* Each time we expand the end of a binding contour (in `expand_end_bindings') |
81 | and we emit a new NOTE_INSN_BLOCK_END note, we save a pointer to it here. | |
82 | This is used by the `remember_end_note' function to record the endpoint | |
83 | of each generated block in its associated BLOCK node. */ | |
84 | ||
85 | static rtx last_block_end_note; | |
86 | ||
28d81abb RK |
87 | /* Number of binding contours started so far in this function. */ |
88 | ||
89 | int block_start_count; | |
90 | ||
91 | /* Nonzero if function being compiled needs to | |
92 | return the address of where it has put a structure value. */ | |
93 | ||
94 | extern int current_function_returns_pcc_struct; | |
95 | ||
96 | /* Label that will go on parm cleanup code, if any. | |
97 | Jumping to this label runs cleanup code for parameters, if | |
98 | such code must be run. Following this code is the logical return label. */ | |
99 | ||
100 | extern rtx cleanup_label; | |
101 | ||
102 | /* Label that will go on function epilogue. | |
103 | Jumping to this label serves as a "return" instruction | |
104 | on machines which require execution of the epilogue on all returns. */ | |
105 | ||
106 | extern rtx return_label; | |
107 | ||
108 | /* List (chain of EXPR_LISTs) of pseudo-regs of SAVE_EXPRs. | |
109 | So we can mark them all live at the end of the function, if nonopt. */ | |
110 | extern rtx save_expr_regs; | |
111 | ||
112 | /* Offset to end of allocated area of stack frame. | |
113 | If stack grows down, this is the address of the last stack slot allocated. | |
114 | If stack grows up, this is the address for the next slot. */ | |
115 | extern int frame_offset; | |
116 | ||
117 | /* Label to jump back to for tail recursion, or 0 if we have | |
118 | not yet needed one for this function. */ | |
119 | extern rtx tail_recursion_label; | |
120 | ||
121 | /* Place after which to insert the tail_recursion_label if we need one. */ | |
122 | extern rtx tail_recursion_reentry; | |
123 | ||
124 | /* Location at which to save the argument pointer if it will need to be | |
125 | referenced. There are two cases where this is done: if nonlocal gotos | |
126 | exist, or if vars whose is an offset from the argument pointer will be | |
127 | needed by inner routines. */ | |
128 | ||
129 | extern rtx arg_pointer_save_area; | |
130 | ||
131 | /* Chain of all RTL_EXPRs that have insns in them. */ | |
132 | extern tree rtl_expr_chain; | |
133 | ||
134 | #if 0 /* Turned off because 0 seems to work just as well. */ | |
135 | /* Cleanup lists are required for binding levels regardless of whether | |
136 | that binding level has cleanups or not. This node serves as the | |
137 | cleanup list whenever an empty list is required. */ | |
138 | static tree empty_cleanup_list; | |
139 | #endif | |
140 | \f | |
141 | /* Functions and data structures for expanding case statements. */ | |
142 | ||
143 | /* Case label structure, used to hold info on labels within case | |
144 | statements. We handle "range" labels; for a single-value label | |
145 | as in C, the high and low limits are the same. | |
146 | ||
147 | A chain of case nodes is initially maintained via the RIGHT fields | |
148 | in the nodes. Nodes with higher case values are later in the list. | |
149 | ||
150 | Switch statements can be output in one of two forms. A branch table | |
151 | is used if there are more than a few labels and the labels are dense | |
152 | within the range between the smallest and largest case value. If a | |
153 | branch table is used, no further manipulations are done with the case | |
154 | node chain. | |
155 | ||
156 | The alternative to the use of a branch table is to generate a series | |
157 | of compare and jump insns. When that is done, we use the LEFT, RIGHT, | |
158 | and PARENT fields to hold a binary tree. Initially the tree is | |
de14fd73 RK |
159 | totally unbalanced, with everything on the right. We balance the tree |
160 | with nodes on the left having lower case values than the parent | |
28d81abb RK |
161 | and nodes on the right having higher values. We then output the tree |
162 | in order. */ | |
163 | ||
164 | struct case_node | |
165 | { | |
166 | struct case_node *left; /* Left son in binary tree */ | |
167 | struct case_node *right; /* Right son in binary tree; also node chain */ | |
168 | struct case_node *parent; /* Parent of node in binary tree */ | |
169 | tree low; /* Lowest index value for this label */ | |
170 | tree high; /* Highest index value for this label */ | |
171 | tree code_label; /* Label to jump to when node matches */ | |
172 | }; | |
173 | ||
174 | typedef struct case_node case_node; | |
175 | typedef struct case_node *case_node_ptr; | |
176 | ||
177 | /* These are used by estimate_case_costs and balance_case_nodes. */ | |
178 | ||
179 | /* This must be a signed type, and non-ANSI compilers lack signed char. */ | |
180 | static short *cost_table; | |
181 | static int use_cost_table; | |
182 | ||
183 | static int estimate_case_costs (); | |
184 | static void balance_case_nodes (); | |
185 | static void emit_case_nodes (); | |
186 | static void group_case_nodes (); | |
187 | static void emit_jump_if_reachable (); | |
188 | ||
189 | static int warn_if_unused_value (); | |
190 | static void expand_goto_internal (); | |
ca695ac9 | 191 | static void bc_expand_goto_internal (); |
28d81abb | 192 | static int expand_fixup (); |
ca695ac9 | 193 | static void bc_expand_fixup (); |
28d81abb | 194 | void fixup_gotos (); |
ca695ac9 | 195 | static void bc_fixup_gotos (); |
28d81abb RK |
196 | void free_temp_slots (); |
197 | static void expand_cleanups (); | |
28d81abb RK |
198 | static void expand_null_return_1 (); |
199 | static int tail_recursion_args (); | |
200 | static void do_jump_if_equal (); | |
ca695ac9 JB |
201 | int bc_expand_exit_loop_if_false (); |
202 | void bc_expand_start_cond (); | |
203 | void bc_expand_end_cond (); | |
204 | void bc_expand_start_else (); | |
205 | void bc_expand_end_bindings (); | |
206 | void bc_expand_start_case (); | |
207 | void bc_check_for_full_enumeration_handling (); | |
208 | void bc_expand_end_case (); | |
209 | void bc_expand_decl (); | |
210 | ||
211 | extern rtx bc_allocate_local (); | |
212 | extern rtx bc_allocate_variable_array (); | |
28d81abb RK |
213 | \f |
214 | /* Stack of control and binding constructs we are currently inside. | |
215 | ||
216 | These constructs begin when you call `expand_start_WHATEVER' | |
217 | and end when you call `expand_end_WHATEVER'. This stack records | |
218 | info about how the construct began that tells the end-function | |
219 | what to do. It also may provide information about the construct | |
220 | to alter the behavior of other constructs within the body. | |
221 | For example, they may affect the behavior of C `break' and `continue'. | |
222 | ||
223 | Each construct gets one `struct nesting' object. | |
224 | All of these objects are chained through the `all' field. | |
225 | `nesting_stack' points to the first object (innermost construct). | |
226 | The position of an entry on `nesting_stack' is in its `depth' field. | |
227 | ||
228 | Each type of construct has its own individual stack. | |
229 | For example, loops have `loop_stack'. Each object points to the | |
230 | next object of the same type through the `next' field. | |
231 | ||
232 | Some constructs are visible to `break' exit-statements and others | |
233 | are not. Which constructs are visible depends on the language. | |
234 | Therefore, the data structure allows each construct to be visible | |
235 | or not, according to the args given when the construct is started. | |
236 | The construct is visible if the `exit_label' field is non-null. | |
237 | In that case, the value should be a CODE_LABEL rtx. */ | |
238 | ||
239 | struct nesting | |
240 | { | |
241 | struct nesting *all; | |
242 | struct nesting *next; | |
243 | int depth; | |
244 | rtx exit_label; | |
245 | union | |
246 | { | |
247 | /* For conds (if-then and if-then-else statements). */ | |
248 | struct | |
249 | { | |
250 | /* Label for the end of the if construct. | |
251 | There is none if EXITFLAG was not set | |
252 | and no `else' has been seen yet. */ | |
253 | rtx endif_label; | |
254 | /* Label for the end of this alternative. | |
255 | This may be the end of the if or the next else/elseif. */ | |
256 | rtx next_label; | |
257 | } cond; | |
258 | /* For loops. */ | |
259 | struct | |
260 | { | |
261 | /* Label at the top of the loop; place to loop back to. */ | |
262 | rtx start_label; | |
263 | /* Label at the end of the whole construct. */ | |
264 | rtx end_label; | |
265 | /* Label for `continue' statement to jump to; | |
266 | this is in front of the stepper of the loop. */ | |
267 | rtx continue_label; | |
268 | } loop; | |
269 | /* For variable binding contours. */ | |
270 | struct | |
271 | { | |
272 | /* Sequence number of this binding contour within the function, | |
273 | in order of entry. */ | |
274 | int block_start_count; | |
ca695ac9 JB |
275 | /* Nonzero => value to restore stack to on exit. Complemented by |
276 | bc_stack_level (see below) when generating bytecodes. */ | |
28d81abb RK |
277 | rtx stack_level; |
278 | /* The NOTE that starts this contour. | |
279 | Used by expand_goto to check whether the destination | |
280 | is within each contour or not. */ | |
281 | rtx first_insn; | |
282 | /* Innermost containing binding contour that has a stack level. */ | |
283 | struct nesting *innermost_stack_block; | |
284 | /* List of cleanups to be run on exit from this contour. | |
285 | This is a list of expressions to be evaluated. | |
286 | The TREE_PURPOSE of each link is the ..._DECL node | |
287 | which the cleanup pertains to. */ | |
288 | tree cleanups; | |
289 | /* List of cleanup-lists of blocks containing this block, | |
290 | as they were at the locus where this block appears. | |
291 | There is an element for each containing block, | |
292 | ordered innermost containing block first. | |
293 | The tail of this list can be 0 (was empty_cleanup_list), | |
294 | if all remaining elements would be empty lists. | |
295 | The element's TREE_VALUE is the cleanup-list of that block, | |
296 | which may be null. */ | |
297 | tree outer_cleanups; | |
298 | /* Chain of labels defined inside this binding contour. | |
299 | For contours that have stack levels or cleanups. */ | |
300 | struct label_chain *label_chain; | |
301 | /* Number of function calls seen, as of start of this block. */ | |
302 | int function_call_count; | |
ca695ac9 JB |
303 | /* Bytecode specific: stack level to restore stack to on exit. */ |
304 | int bc_stack_level; | |
28d81abb RK |
305 | } block; |
306 | /* For switch (C) or case (Pascal) statements, | |
307 | and also for dummies (see `expand_start_case_dummy'). */ | |
308 | struct | |
309 | { | |
310 | /* The insn after which the case dispatch should finally | |
311 | be emitted. Zero for a dummy. */ | |
312 | rtx start; | |
ca695ac9 JB |
313 | /* For bytecodes, the case table is in-lined right in the code. |
314 | A label is needed for skipping over this block. It is only | |
315 | used when generating bytecodes. */ | |
316 | rtx skip_label; | |
28d81abb RK |
317 | /* A list of case labels, kept in ascending order by value |
318 | as the list is built. | |
319 | During expand_end_case, this list may be rearranged into a | |
320 | nearly balanced binary tree. */ | |
321 | struct case_node *case_list; | |
322 | /* Label to jump to if no case matches. */ | |
323 | tree default_label; | |
324 | /* The expression to be dispatched on. */ | |
325 | tree index_expr; | |
326 | /* Type that INDEX_EXPR should be converted to. */ | |
327 | tree nominal_type; | |
328 | /* Number of range exprs in case statement. */ | |
329 | int num_ranges; | |
330 | /* Name of this kind of statement, for warnings. */ | |
331 | char *printname; | |
332 | /* Nonzero if a case label has been seen in this case stmt. */ | |
333 | char seenlabel; | |
334 | } case_stmt; | |
335 | /* For exception contours. */ | |
336 | struct | |
337 | { | |
338 | /* List of exceptions raised. This is a TREE_LIST | |
339 | of whatever you want. */ | |
340 | tree raised; | |
341 | /* List of exceptions caught. This is also a TREE_LIST | |
342 | of whatever you want. As a special case, it has the | |
343 | value `void_type_node' if it handles default exceptions. */ | |
344 | tree handled; | |
345 | ||
346 | /* First insn of TRY block, in case resumptive model is needed. */ | |
347 | rtx first_insn; | |
348 | /* Label for the catch clauses. */ | |
349 | rtx except_label; | |
350 | /* Label for unhandled exceptions. */ | |
351 | rtx unhandled_label; | |
352 | /* Label at the end of whole construct. */ | |
353 | rtx after_label; | |
354 | /* Label which "escapes" the exception construct. | |
355 | Like EXIT_LABEL for BREAK construct, but for exceptions. */ | |
356 | rtx escape_label; | |
357 | } except_stmt; | |
358 | } data; | |
359 | }; | |
360 | ||
361 | /* Chain of all pending binding contours. */ | |
362 | struct nesting *block_stack; | |
363 | ||
6ed1d6c5 RS |
364 | /* If any new stacks are added here, add them to POPSTACKS too. */ |
365 | ||
28d81abb RK |
366 | /* Chain of all pending binding contours that restore stack levels |
367 | or have cleanups. */ | |
368 | struct nesting *stack_block_stack; | |
369 | ||
370 | /* Chain of all pending conditional statements. */ | |
371 | struct nesting *cond_stack; | |
372 | ||
373 | /* Chain of all pending loops. */ | |
374 | struct nesting *loop_stack; | |
375 | ||
376 | /* Chain of all pending case or switch statements. */ | |
377 | struct nesting *case_stack; | |
378 | ||
379 | /* Chain of all pending exception contours. */ | |
380 | struct nesting *except_stack; | |
381 | ||
382 | /* Separate chain including all of the above, | |
383 | chained through the `all' field. */ | |
384 | struct nesting *nesting_stack; | |
385 | ||
386 | /* Number of entries on nesting_stack now. */ | |
387 | int nesting_depth; | |
388 | ||
389 | /* Allocate and return a new `struct nesting'. */ | |
390 | ||
391 | #define ALLOC_NESTING() \ | |
392 | (struct nesting *) obstack_alloc (&stmt_obstack, sizeof (struct nesting)) | |
393 | ||
6ed1d6c5 RS |
394 | /* Pop the nesting stack element by element until we pop off |
395 | the element which is at the top of STACK. | |
396 | Update all the other stacks, popping off elements from them | |
397 | as we pop them from nesting_stack. */ | |
28d81abb RK |
398 | |
399 | #define POPSTACK(STACK) \ | |
6ed1d6c5 RS |
400 | do { struct nesting *target = STACK; \ |
401 | struct nesting *this; \ | |
402 | do { this = nesting_stack; \ | |
403 | if (loop_stack == this) \ | |
404 | loop_stack = loop_stack->next; \ | |
405 | if (cond_stack == this) \ | |
406 | cond_stack = cond_stack->next; \ | |
407 | if (block_stack == this) \ | |
408 | block_stack = block_stack->next; \ | |
409 | if (stack_block_stack == this) \ | |
410 | stack_block_stack = stack_block_stack->next; \ | |
411 | if (case_stack == this) \ | |
412 | case_stack = case_stack->next; \ | |
413 | if (except_stack == this) \ | |
414 | except_stack = except_stack->next; \ | |
415 | nesting_depth = nesting_stack->depth - 1; \ | |
28d81abb | 416 | nesting_stack = this->all; \ |
28d81abb | 417 | obstack_free (&stmt_obstack, this); } \ |
6ed1d6c5 | 418 | while (this != target); } while (0) |
28d81abb RK |
419 | \f |
420 | /* In some cases it is impossible to generate code for a forward goto | |
421 | until the label definition is seen. This happens when it may be necessary | |
422 | for the goto to reset the stack pointer: we don't yet know how to do that. | |
423 | So expand_goto puts an entry on this fixup list. | |
424 | Each time a binding contour that resets the stack is exited, | |
425 | we check each fixup. | |
426 | If the target label has now been defined, we can insert the proper code. */ | |
427 | ||
428 | struct goto_fixup | |
429 | { | |
430 | /* Points to following fixup. */ | |
431 | struct goto_fixup *next; | |
432 | /* Points to the insn before the jump insn. | |
433 | If more code must be inserted, it goes after this insn. */ | |
434 | rtx before_jump; | |
435 | /* The LABEL_DECL that this jump is jumping to, or 0 | |
436 | for break, continue or return. */ | |
437 | tree target; | |
7629c936 RS |
438 | /* The BLOCK for the place where this goto was found. */ |
439 | tree context; | |
28d81abb RK |
440 | /* The CODE_LABEL rtx that this is jumping to. */ |
441 | rtx target_rtl; | |
442 | /* Number of binding contours started in current function | |
443 | before the label reference. */ | |
444 | int block_start_count; | |
445 | /* The outermost stack level that should be restored for this jump. | |
446 | Each time a binding contour that resets the stack is exited, | |
447 | if the target label is *not* yet defined, this slot is updated. */ | |
448 | rtx stack_level; | |
449 | /* List of lists of cleanup expressions to be run by this goto. | |
450 | There is one element for each block that this goto is within. | |
451 | The tail of this list can be 0 (was empty_cleanup_list), | |
452 | if all remaining elements would be empty. | |
453 | The TREE_VALUE contains the cleanup list of that block as of the | |
454 | time this goto was seen. | |
455 | The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */ | |
456 | tree cleanup_list_list; | |
ca695ac9 JB |
457 | |
458 | /* Bytecode specific members follow */ | |
459 | ||
460 | /* The label that this jump is jumping to, or 0 for break, continue | |
461 | or return. */ | |
462 | struct bc_label *bc_target; | |
463 | ||
464 | /* The label we use for the fixup patch */ | |
465 | struct bc_label *label; | |
466 | ||
467 | /* True (non-0) if fixup has been handled */ | |
468 | int bc_handled:1; | |
469 | ||
470 | /* Like stack_level above, except refers to the interpreter stack */ | |
471 | int bc_stack_level; | |
28d81abb RK |
472 | }; |
473 | ||
474 | static struct goto_fixup *goto_fixup_chain; | |
475 | ||
476 | /* Within any binding contour that must restore a stack level, | |
477 | all labels are recorded with a chain of these structures. */ | |
478 | ||
479 | struct label_chain | |
480 | { | |
481 | /* Points to following fixup. */ | |
482 | struct label_chain *next; | |
483 | tree label; | |
484 | }; | |
485 | \f | |
486 | void | |
487 | init_stmt () | |
488 | { | |
489 | gcc_obstack_init (&stmt_obstack); | |
490 | #if 0 | |
491 | empty_cleanup_list = build_tree_list (NULL_TREE, NULL_TREE); | |
492 | #endif | |
493 | } | |
494 | ||
495 | void | |
496 | init_stmt_for_function () | |
497 | { | |
498 | /* We are not currently within any block, conditional, loop or case. */ | |
499 | block_stack = 0; | |
500 | loop_stack = 0; | |
501 | case_stack = 0; | |
502 | cond_stack = 0; | |
503 | nesting_stack = 0; | |
504 | nesting_depth = 0; | |
505 | ||
506 | block_start_count = 0; | |
507 | ||
508 | /* No gotos have been expanded yet. */ | |
509 | goto_fixup_chain = 0; | |
510 | ||
511 | /* We are not processing a ({...}) grouping. */ | |
512 | expr_stmts_for_value = 0; | |
513 | last_expr_type = 0; | |
514 | } | |
515 | ||
516 | void | |
517 | save_stmt_status (p) | |
518 | struct function *p; | |
519 | { | |
520 | p->block_stack = block_stack; | |
521 | p->stack_block_stack = stack_block_stack; | |
522 | p->cond_stack = cond_stack; | |
523 | p->loop_stack = loop_stack; | |
524 | p->case_stack = case_stack; | |
525 | p->nesting_stack = nesting_stack; | |
526 | p->nesting_depth = nesting_depth; | |
527 | p->block_start_count = block_start_count; | |
528 | p->last_expr_type = last_expr_type; | |
529 | p->last_expr_value = last_expr_value; | |
530 | p->expr_stmts_for_value = expr_stmts_for_value; | |
531 | p->emit_filename = emit_filename; | |
532 | p->emit_lineno = emit_lineno; | |
533 | p->goto_fixup_chain = goto_fixup_chain; | |
534 | } | |
535 | ||
536 | void | |
537 | restore_stmt_status (p) | |
538 | struct function *p; | |
539 | { | |
540 | block_stack = p->block_stack; | |
541 | stack_block_stack = p->stack_block_stack; | |
542 | cond_stack = p->cond_stack; | |
543 | loop_stack = p->loop_stack; | |
544 | case_stack = p->case_stack; | |
545 | nesting_stack = p->nesting_stack; | |
546 | nesting_depth = p->nesting_depth; | |
547 | block_start_count = p->block_start_count; | |
548 | last_expr_type = p->last_expr_type; | |
549 | last_expr_value = p->last_expr_value; | |
550 | expr_stmts_for_value = p->expr_stmts_for_value; | |
551 | emit_filename = p->emit_filename; | |
552 | emit_lineno = p->emit_lineno; | |
553 | goto_fixup_chain = p->goto_fixup_chain; | |
554 | } | |
555 | \f | |
556 | /* Emit a no-op instruction. */ | |
557 | ||
558 | void | |
559 | emit_nop () | |
560 | { | |
ca695ac9 JB |
561 | rtx last_insn; |
562 | ||
563 | if (!output_bytecode) | |
564 | { | |
565 | last_insn = get_last_insn (); | |
566 | if (!optimize | |
567 | && (GET_CODE (last_insn) == CODE_LABEL | |
568 | || prev_real_insn (last_insn) == 0)) | |
569 | emit_insn (gen_nop ()); | |
570 | } | |
28d81abb RK |
571 | } |
572 | \f | |
573 | /* Return the rtx-label that corresponds to a LABEL_DECL, | |
574 | creating it if necessary. */ | |
575 | ||
576 | rtx | |
577 | label_rtx (label) | |
578 | tree label; | |
579 | { | |
580 | if (TREE_CODE (label) != LABEL_DECL) | |
581 | abort (); | |
582 | ||
583 | if (DECL_RTL (label)) | |
584 | return DECL_RTL (label); | |
585 | ||
586 | return DECL_RTL (label) = gen_label_rtx (); | |
587 | } | |
588 | ||
589 | /* Add an unconditional jump to LABEL as the next sequential instruction. */ | |
590 | ||
591 | void | |
592 | emit_jump (label) | |
593 | rtx label; | |
594 | { | |
595 | do_pending_stack_adjust (); | |
596 | emit_jump_insn (gen_jump (label)); | |
597 | emit_barrier (); | |
598 | } | |
599 | ||
600 | /* Emit code to jump to the address | |
601 | specified by the pointer expression EXP. */ | |
602 | ||
603 | void | |
604 | expand_computed_goto (exp) | |
605 | tree exp; | |
606 | { | |
ca695ac9 JB |
607 | if (output_bytecode) |
608 | { | |
609 | bc_expand_expr (exp); | |
610 | bc_emit_instruction (jumpP); | |
611 | } | |
612 | else | |
613 | { | |
614 | rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0); | |
615 | emit_queue (); | |
616 | emit_indirect_jump (x); | |
617 | } | |
28d81abb RK |
618 | } |
619 | \f | |
620 | /* Handle goto statements and the labels that they can go to. */ | |
621 | ||
622 | /* Specify the location in the RTL code of a label LABEL, | |
623 | which is a LABEL_DECL tree node. | |
624 | ||
625 | This is used for the kind of label that the user can jump to with a | |
626 | goto statement, and for alternatives of a switch or case statement. | |
627 | RTL labels generated for loops and conditionals don't go through here; | |
628 | they are generated directly at the RTL level, by other functions below. | |
629 | ||
630 | Note that this has nothing to do with defining label *names*. | |
631 | Languages vary in how they do that and what that even means. */ | |
632 | ||
633 | void | |
634 | expand_label (label) | |
635 | tree label; | |
636 | { | |
637 | struct label_chain *p; | |
638 | ||
ca695ac9 JB |
639 | if (output_bytecode) |
640 | { | |
641 | if (! DECL_RTL (label)) | |
642 | DECL_RTL (label) = bc_gen_rtx ((char *) 0, 0, bc_get_bytecode_label ()); | |
c53e9440 | 643 | if (! bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (DECL_RTL (label)))) |
ca695ac9 JB |
644 | error ("multiply defined label"); |
645 | return; | |
646 | } | |
647 | ||
28d81abb RK |
648 | do_pending_stack_adjust (); |
649 | emit_label (label_rtx (label)); | |
650 | if (DECL_NAME (label)) | |
651 | LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label)); | |
652 | ||
653 | if (stack_block_stack != 0) | |
654 | { | |
655 | p = (struct label_chain *) oballoc (sizeof (struct label_chain)); | |
656 | p->next = stack_block_stack->data.block.label_chain; | |
657 | stack_block_stack->data.block.label_chain = p; | |
658 | p->label = label; | |
659 | } | |
660 | } | |
661 | ||
662 | /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos | |
663 | from nested functions. */ | |
664 | ||
665 | void | |
666 | declare_nonlocal_label (label) | |
667 | tree label; | |
668 | { | |
669 | nonlocal_labels = tree_cons (NULL_TREE, label, nonlocal_labels); | |
670 | LABEL_PRESERVE_P (label_rtx (label)) = 1; | |
671 | if (nonlocal_goto_handler_slot == 0) | |
672 | { | |
673 | nonlocal_goto_handler_slot | |
674 | = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0); | |
59257ff7 RK |
675 | emit_stack_save (SAVE_NONLOCAL, |
676 | &nonlocal_goto_stack_level, | |
677 | PREV_INSN (tail_recursion_reentry)); | |
28d81abb RK |
678 | } |
679 | } | |
680 | ||
681 | /* Generate RTL code for a `goto' statement with target label LABEL. | |
682 | LABEL should be a LABEL_DECL tree node that was or will later be | |
683 | defined with `expand_label'. */ | |
684 | ||
685 | void | |
686 | expand_goto (label) | |
687 | tree label; | |
688 | { | |
ca695ac9 JB |
689 | tree context; |
690 | ||
691 | if (output_bytecode) | |
692 | { | |
693 | expand_goto_internal (label, label_rtx (label), NULL_RTX); | |
694 | return; | |
695 | } | |
696 | ||
28d81abb | 697 | /* Check for a nonlocal goto to a containing function. */ |
ca695ac9 | 698 | context = decl_function_context (label); |
28d81abb RK |
699 | if (context != 0 && context != current_function_decl) |
700 | { | |
701 | struct function *p = find_function_data (context); | |
dd132134 | 702 | rtx label_ref = gen_rtx (LABEL_REF, Pmode, label_rtx (label)); |
28d81abb | 703 | rtx temp; |
dd132134 | 704 | |
28d81abb | 705 | p->has_nonlocal_label = 1; |
c1255328 | 706 | current_function_has_nonlocal_goto = 1; |
dd132134 | 707 | LABEL_REF_NONLOCAL_P (label_ref) = 1; |
59257ff7 RK |
708 | |
709 | /* Copy the rtl for the slots so that they won't be shared in | |
710 | case the virtual stack vars register gets instantiated differently | |
711 | in the parent than in the child. */ | |
712 | ||
28d81abb RK |
713 | #if HAVE_nonlocal_goto |
714 | if (HAVE_nonlocal_goto) | |
715 | emit_insn (gen_nonlocal_goto (lookup_static_chain (label), | |
59257ff7 RK |
716 | copy_rtx (p->nonlocal_goto_handler_slot), |
717 | copy_rtx (p->nonlocal_goto_stack_level), | |
dd132134 | 718 | label_ref)); |
28d81abb RK |
719 | else |
720 | #endif | |
721 | { | |
59257ff7 RK |
722 | rtx addr; |
723 | ||
28d81abb RK |
724 | /* Restore frame pointer for containing function. |
725 | This sets the actual hard register used for the frame pointer | |
726 | to the location of the function's incoming static chain info. | |
727 | The non-local goto handler will then adjust it to contain the | |
728 | proper value and reload the argument pointer, if needed. */ | |
a35ad168 | 729 | emit_move_insn (hard_frame_pointer_rtx, lookup_static_chain (label)); |
59257ff7 RK |
730 | |
731 | /* We have now loaded the frame pointer hardware register with | |
732 | the address of that corresponds to the start of the virtual | |
733 | stack vars. So replace virtual_stack_vars_rtx in all | |
734 | addresses we use with stack_pointer_rtx. */ | |
735 | ||
28d81abb RK |
736 | /* Get addr of containing function's current nonlocal goto handler, |
737 | which will do any cleanups and then jump to the label. */ | |
59257ff7 RK |
738 | addr = copy_rtx (p->nonlocal_goto_handler_slot); |
739 | temp = copy_to_reg (replace_rtx (addr, virtual_stack_vars_rtx, | |
a35ad168 | 740 | hard_frame_pointer_rtx)); |
59257ff7 | 741 | |
28d81abb | 742 | /* Restore the stack pointer. Note this uses fp just restored. */ |
59257ff7 RK |
743 | addr = p->nonlocal_goto_stack_level; |
744 | if (addr) | |
5e116627 | 745 | addr = replace_rtx (copy_rtx (addr), |
a35ad168 DE |
746 | virtual_stack_vars_rtx, |
747 | hard_frame_pointer_rtx); | |
59257ff7 | 748 | |
37366632 | 749 | emit_stack_restore (SAVE_NONLOCAL, addr, NULL_RTX); |
59257ff7 | 750 | |
28d81abb | 751 | /* Put in the static chain register the nonlocal label address. */ |
dd132134 | 752 | emit_move_insn (static_chain_rtx, label_ref); |
a35ad168 | 753 | /* USE of hard_frame_pointer_rtx added for consistency; not clear if |
28d81abb | 754 | really needed. */ |
a35ad168 | 755 | emit_insn (gen_rtx (USE, VOIDmode, hard_frame_pointer_rtx)); |
28d81abb RK |
756 | emit_insn (gen_rtx (USE, VOIDmode, stack_pointer_rtx)); |
757 | emit_insn (gen_rtx (USE, VOIDmode, static_chain_rtx)); | |
758 | emit_indirect_jump (temp); | |
759 | } | |
760 | } | |
761 | else | |
37366632 | 762 | expand_goto_internal (label, label_rtx (label), NULL_RTX); |
28d81abb RK |
763 | } |
764 | ||
765 | /* Generate RTL code for a `goto' statement with target label BODY. | |
766 | LABEL should be a LABEL_REF. | |
767 | LAST_INSN, if non-0, is the rtx we should consider as the last | |
768 | insn emitted (for the purposes of cleaning up a return). */ | |
769 | ||
770 | static void | |
771 | expand_goto_internal (body, label, last_insn) | |
772 | tree body; | |
773 | rtx label; | |
774 | rtx last_insn; | |
775 | { | |
776 | struct nesting *block; | |
777 | rtx stack_level = 0; | |
778 | ||
ca695ac9 JB |
779 | /* NOTICE! If a bytecode instruction other than `jump' is needed, |
780 | then the caller has to call bc_expand_goto_internal() | |
781 | directly. This is rather an exceptional case, and there aren't | |
782 | that many places where this is necessary. */ | |
783 | if (output_bytecode) | |
784 | { | |
785 | expand_goto_internal (body, label, last_insn); | |
786 | return; | |
787 | } | |
788 | ||
28d81abb RK |
789 | if (GET_CODE (label) != CODE_LABEL) |
790 | abort (); | |
791 | ||
792 | /* If label has already been defined, we can tell now | |
793 | whether and how we must alter the stack level. */ | |
794 | ||
795 | if (PREV_INSN (label) != 0) | |
796 | { | |
797 | /* Find the innermost pending block that contains the label. | |
798 | (Check containment by comparing insn-uids.) | |
799 | Then restore the outermost stack level within that block, | |
800 | and do cleanups of all blocks contained in it. */ | |
801 | for (block = block_stack; block; block = block->next) | |
802 | { | |
803 | if (INSN_UID (block->data.block.first_insn) < INSN_UID (label)) | |
804 | break; | |
805 | if (block->data.block.stack_level != 0) | |
806 | stack_level = block->data.block.stack_level; | |
807 | /* Execute the cleanups for blocks we are exiting. */ | |
808 | if (block->data.block.cleanups != 0) | |
809 | { | |
37366632 | 810 | expand_cleanups (block->data.block.cleanups, NULL_TREE); |
28d81abb RK |
811 | do_pending_stack_adjust (); |
812 | } | |
813 | } | |
814 | ||
815 | if (stack_level) | |
816 | { | |
817 | /* Ensure stack adjust isn't done by emit_jump, as this would clobber | |
818 | the stack pointer. This one should be deleted as dead by flow. */ | |
819 | clear_pending_stack_adjust (); | |
820 | do_pending_stack_adjust (); | |
37366632 | 821 | emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX); |
28d81abb RK |
822 | } |
823 | ||
824 | if (body != 0 && DECL_TOO_LATE (body)) | |
825 | error ("jump to `%s' invalidly jumps into binding contour", | |
826 | IDENTIFIER_POINTER (DECL_NAME (body))); | |
827 | } | |
828 | /* Label not yet defined: may need to put this goto | |
829 | on the fixup list. */ | |
830 | else if (! expand_fixup (body, label, last_insn)) | |
831 | { | |
832 | /* No fixup needed. Record that the label is the target | |
833 | of at least one goto that has no fixup. */ | |
834 | if (body != 0) | |
835 | TREE_ADDRESSABLE (body) = 1; | |
836 | } | |
837 | ||
838 | emit_jump (label); | |
839 | } | |
840 | \f | |
ca695ac9 JB |
841 | /* Generate a jump with OPCODE to the given bytecode LABEL which is |
842 | found within BODY. */ | |
843 | static void | |
844 | bc_expand_goto_internal (opcode, label, body) | |
845 | enum bytecode_opcode opcode; | |
846 | struct bc_label *label; | |
847 | tree body; | |
848 | { | |
849 | struct nesting *block; | |
850 | int stack_level = -1; | |
851 | ||
852 | /* If the label is defined, adjust the stack as necessary. | |
853 | If it's not defined, we have to push the reference on the | |
854 | fixup list. */ | |
855 | ||
856 | if (label->defined) | |
857 | { | |
858 | ||
859 | /* Find the innermost pending block that contains the label. | |
860 | (Check containment by comparing bytecode uids.) Then restore the | |
861 | outermost stack level within that block. */ | |
862 | ||
863 | for (block = block_stack; block; block = block->next) | |
864 | { | |
c53e9440 | 865 | if (BYTECODE_BC_LABEL (block->data.block.first_insn)->uid < label->uid) |
ca695ac9 JB |
866 | break; |
867 | if (block->data.block.bc_stack_level) | |
868 | stack_level = block->data.block.bc_stack_level; | |
869 | ||
870 | /* Execute the cleanups for blocks we are exiting. */ | |
871 | if (block->data.block.cleanups != 0) | |
872 | { | |
873 | expand_cleanups (block->data.block.cleanups, NULL_TREE); | |
874 | do_pending_stack_adjust (); | |
875 | } | |
876 | } | |
877 | ||
878 | /* Restore the stack level. If we need to adjust the stack, we | |
879 | must do so after the jump, since the jump may depend on | |
880 | what's on the stack. Thus, any stack-modifying conditional | |
881 | jumps (these are the only ones that rely on what's on the | |
882 | stack) go into the fixup list. */ | |
883 | ||
884 | if (stack_level >= 0 | |
885 | && stack_depth != stack_level | |
886 | && opcode != jump) | |
887 | ||
888 | bc_expand_fixup (opcode, label, stack_level); | |
889 | else | |
890 | { | |
891 | if (stack_level >= 0) | |
892 | bc_adjust_stack (stack_depth - stack_level); | |
893 | ||
894 | if (body && DECL_BIT_FIELD (body)) | |
895 | error ("jump to `%s' invalidly jumps into binding contour", | |
896 | IDENTIFIER_POINTER (DECL_NAME (body))); | |
897 | ||
898 | /* Emit immediate jump */ | |
899 | bc_emit_bytecode (opcode); | |
900 | bc_emit_bytecode_labelref (label); | |
901 | ||
902 | #ifdef DEBUG_PRINT_CODE | |
903 | fputc ('\n', stderr); | |
904 | #endif | |
905 | } | |
906 | } | |
907 | else | |
908 | /* Put goto in the fixup list */ | |
909 | bc_expand_fixup (opcode, label, stack_level); | |
910 | } | |
911 | \f | |
28d81abb RK |
912 | /* Generate if necessary a fixup for a goto |
913 | whose target label in tree structure (if any) is TREE_LABEL | |
914 | and whose target in rtl is RTL_LABEL. | |
915 | ||
916 | If LAST_INSN is nonzero, we pretend that the jump appears | |
917 | after insn LAST_INSN instead of at the current point in the insn stream. | |
918 | ||
023b57e6 RS |
919 | The fixup will be used later to insert insns just before the goto. |
920 | Those insns will restore the stack level as appropriate for the | |
921 | target label, and will (in the case of C++) also invoke any object | |
922 | destructors which have to be invoked when we exit the scopes which | |
923 | are exited by the goto. | |
28d81abb RK |
924 | |
925 | Value is nonzero if a fixup is made. */ | |
926 | ||
927 | static int | |
928 | expand_fixup (tree_label, rtl_label, last_insn) | |
929 | tree tree_label; | |
930 | rtx rtl_label; | |
931 | rtx last_insn; | |
932 | { | |
933 | struct nesting *block, *end_block; | |
934 | ||
935 | /* See if we can recognize which block the label will be output in. | |
936 | This is possible in some very common cases. | |
937 | If we succeed, set END_BLOCK to that block. | |
938 | Otherwise, set it to 0. */ | |
939 | ||
940 | if (cond_stack | |
941 | && (rtl_label == cond_stack->data.cond.endif_label | |
942 | || rtl_label == cond_stack->data.cond.next_label)) | |
943 | end_block = cond_stack; | |
944 | /* If we are in a loop, recognize certain labels which | |
945 | are likely targets. This reduces the number of fixups | |
946 | we need to create. */ | |
947 | else if (loop_stack | |
948 | && (rtl_label == loop_stack->data.loop.start_label | |
949 | || rtl_label == loop_stack->data.loop.end_label | |
950 | || rtl_label == loop_stack->data.loop.continue_label)) | |
951 | end_block = loop_stack; | |
952 | else | |
953 | end_block = 0; | |
954 | ||
955 | /* Now set END_BLOCK to the binding level to which we will return. */ | |
956 | ||
957 | if (end_block) | |
958 | { | |
959 | struct nesting *next_block = end_block->all; | |
960 | block = block_stack; | |
961 | ||
962 | /* First see if the END_BLOCK is inside the innermost binding level. | |
963 | If so, then no cleanups or stack levels are relevant. */ | |
964 | while (next_block && next_block != block) | |
965 | next_block = next_block->all; | |
966 | ||
967 | if (next_block) | |
968 | return 0; | |
969 | ||
970 | /* Otherwise, set END_BLOCK to the innermost binding level | |
971 | which is outside the relevant control-structure nesting. */ | |
972 | next_block = block_stack->next; | |
973 | for (block = block_stack; block != end_block; block = block->all) | |
974 | if (block == next_block) | |
975 | next_block = next_block->next; | |
976 | end_block = next_block; | |
977 | } | |
978 | ||
979 | /* Does any containing block have a stack level or cleanups? | |
980 | If not, no fixup is needed, and that is the normal case | |
981 | (the only case, for standard C). */ | |
982 | for (block = block_stack; block != end_block; block = block->next) | |
983 | if (block->data.block.stack_level != 0 | |
984 | || block->data.block.cleanups != 0) | |
985 | break; | |
986 | ||
987 | if (block != end_block) | |
988 | { | |
989 | /* Ok, a fixup is needed. Add a fixup to the list of such. */ | |
990 | struct goto_fixup *fixup | |
991 | = (struct goto_fixup *) oballoc (sizeof (struct goto_fixup)); | |
992 | /* In case an old stack level is restored, make sure that comes | |
993 | after any pending stack adjust. */ | |
994 | /* ?? If the fixup isn't to come at the present position, | |
995 | doing the stack adjust here isn't useful. Doing it with our | |
996 | settings at that location isn't useful either. Let's hope | |
997 | someone does it! */ | |
998 | if (last_insn == 0) | |
999 | do_pending_stack_adjust (); | |
28d81abb RK |
1000 | fixup->target = tree_label; |
1001 | fixup->target_rtl = rtl_label; | |
023b57e6 RS |
1002 | |
1003 | /* Create a BLOCK node and a corresponding matched set of | |
1004 | NOTE_INSN_BEGIN_BLOCK and NOTE_INSN_END_BLOCK notes at | |
1005 | this point. The notes will encapsulate any and all fixup | |
1006 | code which we might later insert at this point in the insn | |
1007 | stream. Also, the BLOCK node will be the parent (i.e. the | |
1008 | `SUPERBLOCK') of any other BLOCK nodes which we might create | |
1009 | later on when we are expanding the fixup code. */ | |
1010 | ||
1011 | { | |
1012 | register rtx original_before_jump | |
1013 | = last_insn ? last_insn : get_last_insn (); | |
1014 | ||
1015 | start_sequence (); | |
1016 | pushlevel (0); | |
1017 | fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG); | |
1018 | last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END); | |
1019 | fixup->context = poplevel (1, 0, 0); /* Create the BLOCK node now! */ | |
1020 | end_sequence (); | |
1021 | emit_insns_after (fixup->before_jump, original_before_jump); | |
1022 | } | |
1023 | ||
28d81abb RK |
1024 | fixup->block_start_count = block_start_count; |
1025 | fixup->stack_level = 0; | |
1026 | fixup->cleanup_list_list | |
1027 | = (((block->data.block.outer_cleanups | |
1028 | #if 0 | |
1029 | && block->data.block.outer_cleanups != empty_cleanup_list | |
1030 | #endif | |
1031 | ) | |
1032 | || block->data.block.cleanups) | |
37366632 | 1033 | ? tree_cons (NULL_TREE, block->data.block.cleanups, |
28d81abb RK |
1034 | block->data.block.outer_cleanups) |
1035 | : 0); | |
1036 | fixup->next = goto_fixup_chain; | |
1037 | goto_fixup_chain = fixup; | |
1038 | } | |
1039 | ||
1040 | return block != 0; | |
1041 | } | |
1042 | ||
ca695ac9 JB |
1043 | |
1044 | /* Generate bytecode jump with OPCODE to a fixup routine that links to LABEL. | |
1045 | Make the fixup restore the stack level to STACK_LEVEL. */ | |
1046 | ||
1047 | static void | |
1048 | bc_expand_fixup (opcode, label, stack_level) | |
1049 | enum bytecode_opcode opcode; | |
1050 | struct bc_label *label; | |
1051 | int stack_level; | |
1052 | { | |
1053 | struct goto_fixup *fixup | |
1054 | = (struct goto_fixup *) oballoc (sizeof (struct goto_fixup)); | |
1055 | ||
1056 | fixup->label = bc_get_bytecode_label (); | |
1057 | fixup->bc_target = label; | |
1058 | fixup->bc_stack_level = stack_level; | |
1059 | fixup->bc_handled = FALSE; | |
1060 | ||
1061 | fixup->next = goto_fixup_chain; | |
1062 | goto_fixup_chain = fixup; | |
1063 | ||
1064 | /* Insert a jump to the fixup code */ | |
1065 | bc_emit_bytecode (opcode); | |
1066 | bc_emit_bytecode_labelref (fixup->label); | |
1067 | ||
1068 | #ifdef DEBUG_PRINT_CODE | |
1069 | fputc ('\n', stderr); | |
1070 | #endif | |
1071 | } | |
1072 | ||
1073 | ||
28d81abb RK |
1074 | /* When exiting a binding contour, process all pending gotos requiring fixups. |
1075 | THISBLOCK is the structure that describes the block being exited. | |
1076 | STACK_LEVEL is the rtx for the stack level to restore exiting this contour. | |
1077 | CLEANUP_LIST is a list of expressions to evaluate on exiting this contour. | |
1078 | FIRST_INSN is the insn that began this contour. | |
1079 | ||
1080 | Gotos that jump out of this contour must restore the | |
1081 | stack level and do the cleanups before actually jumping. | |
1082 | ||
1083 | DONT_JUMP_IN nonzero means report error there is a jump into this | |
1084 | contour from before the beginning of the contour. | |
1085 | This is also done if STACK_LEVEL is nonzero. */ | |
1086 | ||
1087 | void | |
1088 | fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in) | |
1089 | struct nesting *thisblock; | |
1090 | rtx stack_level; | |
1091 | tree cleanup_list; | |
1092 | rtx first_insn; | |
1093 | int dont_jump_in; | |
1094 | { | |
1095 | register struct goto_fixup *f, *prev; | |
1096 | ||
ca695ac9 JB |
1097 | if (output_bytecode) |
1098 | { | |
1099 | bc_fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in); | |
1100 | return; | |
1101 | } | |
1102 | ||
28d81abb RK |
1103 | /* F is the fixup we are considering; PREV is the previous one. */ |
1104 | /* We run this loop in two passes so that cleanups of exited blocks | |
1105 | are run first, and blocks that are exited are marked so | |
1106 | afterwards. */ | |
1107 | ||
1108 | for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next) | |
1109 | { | |
1110 | /* Test for a fixup that is inactive because it is already handled. */ | |
1111 | if (f->before_jump == 0) | |
1112 | { | |
1113 | /* Delete inactive fixup from the chain, if that is easy to do. */ | |
1114 | if (prev != 0) | |
1115 | prev->next = f->next; | |
1116 | } | |
1117 | /* Has this fixup's target label been defined? | |
1118 | If so, we can finalize it. */ | |
1119 | else if (PREV_INSN (f->target_rtl) != 0) | |
1120 | { | |
7629c936 | 1121 | register rtx cleanup_insns; |
7629c936 | 1122 | |
28d81abb RK |
1123 | /* Get the first non-label after the label |
1124 | this goto jumps to. If that's before this scope begins, | |
1125 | we don't have a jump into the scope. */ | |
1126 | rtx after_label = f->target_rtl; | |
1127 | while (after_label != 0 && GET_CODE (after_label) == CODE_LABEL) | |
1128 | after_label = NEXT_INSN (after_label); | |
1129 | ||
1130 | /* If this fixup jumped into this contour from before the beginning | |
1131 | of this contour, report an error. */ | |
1132 | /* ??? Bug: this does not detect jumping in through intermediate | |
1133 | blocks that have stack levels or cleanups. | |
1134 | It detects only a problem with the innermost block | |
1135 | around the label. */ | |
1136 | if (f->target != 0 | |
1137 | && (dont_jump_in || stack_level || cleanup_list) | |
1138 | /* If AFTER_LABEL is 0, it means the jump goes to the end | |
1139 | of the rtl, which means it jumps into this scope. */ | |
1140 | && (after_label == 0 | |
1141 | || INSN_UID (first_insn) < INSN_UID (after_label)) | |
1142 | && INSN_UID (first_insn) > INSN_UID (f->before_jump) | |
44fe2e80 | 1143 | && ! DECL_REGISTER (f->target)) |
28d81abb RK |
1144 | { |
1145 | error_with_decl (f->target, | |
1146 | "label `%s' used before containing binding contour"); | |
1147 | /* Prevent multiple errors for one label. */ | |
44fe2e80 | 1148 | DECL_REGISTER (f->target) = 1; |
28d81abb RK |
1149 | } |
1150 | ||
7629c936 RS |
1151 | /* We will expand the cleanups into a sequence of their own and |
1152 | then later on we will attach this new sequence to the insn | |
1153 | stream just ahead of the actual jump insn. */ | |
1154 | ||
1155 | start_sequence (); | |
1156 | ||
023b57e6 RS |
1157 | /* Temporarily restore the lexical context where we will |
1158 | logically be inserting the fixup code. We do this for the | |
1159 | sake of getting the debugging information right. */ | |
1160 | ||
7629c936 | 1161 | pushlevel (0); |
023b57e6 | 1162 | set_block (f->context); |
7629c936 RS |
1163 | |
1164 | /* Expand the cleanups for blocks this jump exits. */ | |
28d81abb RK |
1165 | if (f->cleanup_list_list) |
1166 | { | |
1167 | tree lists; | |
1168 | for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists)) | |
1169 | /* Marked elements correspond to blocks that have been closed. | |
1170 | Do their cleanups. */ | |
1171 | if (TREE_ADDRESSABLE (lists) | |
1172 | && TREE_VALUE (lists) != 0) | |
7629c936 RS |
1173 | { |
1174 | expand_cleanups (TREE_VALUE (lists), 0); | |
1175 | /* Pop any pushes done in the cleanups, | |
1176 | in case function is about to return. */ | |
1177 | do_pending_stack_adjust (); | |
1178 | } | |
28d81abb RK |
1179 | } |
1180 | ||
1181 | /* Restore stack level for the biggest contour that this | |
1182 | jump jumps out of. */ | |
1183 | if (f->stack_level) | |
59257ff7 | 1184 | emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump); |
7629c936 RS |
1185 | |
1186 | /* Finish up the sequence containing the insns which implement the | |
1187 | necessary cleanups, and then attach that whole sequence to the | |
1188 | insn stream just ahead of the actual jump insn. Attaching it | |
1189 | at that point insures that any cleanups which are in fact | |
1190 | implicit C++ object destructions (which must be executed upon | |
1191 | leaving the block) appear (to the debugger) to be taking place | |
1192 | in an area of the generated code where the object(s) being | |
1193 | destructed are still "in scope". */ | |
1194 | ||
1195 | cleanup_insns = get_insns (); | |
023b57e6 | 1196 | poplevel (1, 0, 0); |
7629c936 RS |
1197 | |
1198 | end_sequence (); | |
1199 | emit_insns_after (cleanup_insns, f->before_jump); | |
1200 | ||
7629c936 | 1201 | |
28d81abb RK |
1202 | f->before_jump = 0; |
1203 | } | |
1204 | } | |
1205 | ||
1206 | /* Mark the cleanups of exited blocks so that they are executed | |
1207 | by the code above. */ | |
1208 | for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next) | |
1209 | if (f->before_jump != 0 | |
1210 | && PREV_INSN (f->target_rtl) == 0 | |
1211 | /* Label has still not appeared. If we are exiting a block with | |
1212 | a stack level to restore, that started before the fixup, | |
1213 | mark this stack level as needing restoration | |
1214 | when the fixup is later finalized. | |
1215 | Also mark the cleanup_list_list element for F | |
1216 | that corresponds to this block, so that ultimately | |
1217 | this block's cleanups will be executed by the code above. */ | |
1218 | && thisblock != 0 | |
1219 | /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, | |
1220 | it means the label is undefined. That's erroneous, but possible. */ | |
1221 | && (thisblock->data.block.block_start_count | |
1222 | <= f->block_start_count)) | |
1223 | { | |
1224 | tree lists = f->cleanup_list_list; | |
1225 | for (; lists; lists = TREE_CHAIN (lists)) | |
1226 | /* If the following elt. corresponds to our containing block | |
1227 | then the elt. must be for this block. */ | |
1228 | if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups) | |
1229 | TREE_ADDRESSABLE (lists) = 1; | |
1230 | ||
1231 | if (stack_level) | |
1232 | f->stack_level = stack_level; | |
1233 | } | |
1234 | } | |
ca695ac9 JB |
1235 | |
1236 | ||
1237 | /* When exiting a binding contour, process all pending gotos requiring fixups. | |
1238 | Note: STACK_DEPTH is not altered. | |
1239 | ||
1240 | The arguments are currently not used in the bytecode compiler, but we may need | |
1241 | them one day for languages other than C. | |
1242 | ||
1243 | THISBLOCK is the structure that describes the block being exited. | |
1244 | STACK_LEVEL is the rtx for the stack level to restore exiting this contour. | |
1245 | CLEANUP_LIST is a list of expressions to evaluate on exiting this contour. | |
1246 | FIRST_INSN is the insn that began this contour. | |
1247 | ||
1248 | Gotos that jump out of this contour must restore the | |
1249 | stack level and do the cleanups before actually jumping. | |
1250 | ||
1251 | DONT_JUMP_IN nonzero means report error there is a jump into this | |
1252 | contour from before the beginning of the contour. | |
1253 | This is also done if STACK_LEVEL is nonzero. */ | |
1254 | ||
1255 | static void | |
1256 | bc_fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in) | |
1257 | struct nesting *thisblock; | |
1258 | int stack_level; | |
1259 | tree cleanup_list; | |
1260 | rtx first_insn; | |
1261 | int dont_jump_in; | |
1262 | { | |
1263 | register struct goto_fixup *f, *prev; | |
1264 | int saved_stack_depth; | |
1265 | ||
1266 | /* F is the fixup we are considering; PREV is the previous one. */ | |
1267 | ||
1268 | for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next) | |
1269 | { | |
1270 | /* Test for a fixup that is inactive because it is already handled. */ | |
1271 | if (f->before_jump == 0) | |
1272 | { | |
1273 | /* Delete inactive fixup from the chain, if that is easy to do. */ | |
1274 | if (prev) | |
1275 | prev->next = f->next; | |
1276 | } | |
1277 | ||
1278 | /* Emit code to restore the stack and continue */ | |
1279 | bc_emit_bytecode_labeldef (f->label); | |
1280 | ||
1281 | /* Save stack_depth across call, since bc_adjust_stack () will alter | |
1282 | the perceived stack depth via the instructions generated. */ | |
1283 | ||
1284 | if (f->bc_stack_level >= 0) | |
1285 | { | |
1286 | saved_stack_depth = stack_depth; | |
1287 | bc_adjust_stack (stack_depth - f->bc_stack_level); | |
1288 | stack_depth = saved_stack_depth; | |
1289 | } | |
1290 | ||
1291 | bc_emit_bytecode (jump); | |
1292 | bc_emit_bytecode_labelref (f->bc_target); | |
1293 | ||
1294 | #ifdef DEBUG_PRINT_CODE | |
1295 | fputc ('\n', stderr); | |
1296 | #endif | |
1297 | } | |
1298 | ||
1299 | goto_fixup_chain = NULL; | |
1300 | } | |
28d81abb RK |
1301 | \f |
1302 | /* Generate RTL for an asm statement (explicit assembler code). | |
1303 | BODY is a STRING_CST node containing the assembler code text, | |
1304 | or an ADDR_EXPR containing a STRING_CST. */ | |
1305 | ||
1306 | void | |
1307 | expand_asm (body) | |
1308 | tree body; | |
1309 | { | |
ca695ac9 JB |
1310 | if (output_bytecode) |
1311 | { | |
1312 | error ("`asm' is illegal when generating bytecode"); | |
1313 | return; | |
1314 | } | |
1315 | ||
28d81abb RK |
1316 | if (TREE_CODE (body) == ADDR_EXPR) |
1317 | body = TREE_OPERAND (body, 0); | |
1318 | ||
1319 | emit_insn (gen_rtx (ASM_INPUT, VOIDmode, | |
1320 | TREE_STRING_POINTER (body))); | |
1321 | last_expr_type = 0; | |
1322 | } | |
1323 | ||
1324 | /* Generate RTL for an asm statement with arguments. | |
1325 | STRING is the instruction template. | |
1326 | OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs. | |
1327 | Each output or input has an expression in the TREE_VALUE and | |
1328 | a constraint-string in the TREE_PURPOSE. | |
1329 | CLOBBERS is a list of STRING_CST nodes each naming a hard register | |
1330 | that is clobbered by this insn. | |
1331 | ||
1332 | Not all kinds of lvalue that may appear in OUTPUTS can be stored directly. | |
1333 | Some elements of OUTPUTS may be replaced with trees representing temporary | |
1334 | values. The caller should copy those temporary values to the originally | |
1335 | specified lvalues. | |
1336 | ||
1337 | VOL nonzero means the insn is volatile; don't optimize it. */ | |
1338 | ||
1339 | void | |
1340 | expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line) | |
1341 | tree string, outputs, inputs, clobbers; | |
1342 | int vol; | |
1343 | char *filename; | |
1344 | int line; | |
1345 | { | |
1346 | rtvec argvec, constraints; | |
1347 | rtx body; | |
1348 | int ninputs = list_length (inputs); | |
1349 | int noutputs = list_length (outputs); | |
b4ccaa16 | 1350 | int nclobbers; |
28d81abb RK |
1351 | tree tail; |
1352 | register int i; | |
1353 | /* Vector of RTX's of evaluated output operands. */ | |
1354 | rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx)); | |
1355 | /* The insn we have emitted. */ | |
1356 | rtx insn; | |
1357 | ||
ca695ac9 JB |
1358 | if (output_bytecode) |
1359 | { | |
1360 | error ("`asm' is illegal when generating bytecode"); | |
1361 | return; | |
1362 | } | |
1363 | ||
b4ccaa16 RS |
1364 | /* Count the number of meaningful clobbered registers, ignoring what |
1365 | we would ignore later. */ | |
1366 | nclobbers = 0; | |
1367 | for (tail = clobbers; tail; tail = TREE_CHAIN (tail)) | |
1368 | { | |
1369 | char *regname = TREE_STRING_POINTER (TREE_VALUE (tail)); | |
c09e6498 RS |
1370 | i = decode_reg_name (regname); |
1371 | if (i >= 0 || i == -4) | |
b4ccaa16 RS |
1372 | ++nclobbers; |
1373 | } | |
1374 | ||
28d81abb RK |
1375 | last_expr_type = 0; |
1376 | ||
1377 | for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++) | |
1378 | { | |
1379 | tree val = TREE_VALUE (tail); | |
1380 | tree val1; | |
1381 | int j; | |
1382 | int found_equal; | |
1383 | ||
1384 | /* If there's an erroneous arg, emit no insn. */ | |
1385 | if (TREE_TYPE (val) == error_mark_node) | |
1386 | return; | |
1387 | ||
1388 | /* Make sure constraint has `=' and does not have `+'. */ | |
1389 | ||
1390 | found_equal = 0; | |
1391 | for (j = 0; j < TREE_STRING_LENGTH (TREE_PURPOSE (tail)); j++) | |
1392 | { | |
1393 | if (TREE_STRING_POINTER (TREE_PURPOSE (tail))[j] == '+') | |
1394 | { | |
1395 | error ("output operand constraint contains `+'"); | |
1396 | return; | |
1397 | } | |
1398 | if (TREE_STRING_POINTER (TREE_PURPOSE (tail))[j] == '=') | |
1399 | found_equal = 1; | |
1400 | } | |
1401 | if (! found_equal) | |
1402 | { | |
1403 | error ("output operand constraint lacks `='"); | |
1404 | return; | |
1405 | } | |
1406 | ||
1407 | /* If an output operand is not a variable or indirect ref, | |
1408 | or a part of one, | |
1409 | create a SAVE_EXPR which is a pseudo-reg | |
1410 | to act as an intermediate temporary. | |
1411 | Make the asm insn write into that, then copy it to | |
1412 | the real output operand. */ | |
1413 | ||
1414 | while (TREE_CODE (val) == COMPONENT_REF | |
1415 | || TREE_CODE (val) == ARRAY_REF) | |
1416 | val = TREE_OPERAND (val, 0); | |
1417 | ||
1418 | if (TREE_CODE (val) != VAR_DECL | |
1419 | && TREE_CODE (val) != PARM_DECL | |
1420 | && TREE_CODE (val) != INDIRECT_REF) | |
e619bb8d RS |
1421 | { |
1422 | TREE_VALUE (tail) = save_expr (TREE_VALUE (tail)); | |
1423 | /* If it's a constant, print error now so don't crash later. */ | |
1424 | if (TREE_CODE (TREE_VALUE (tail)) != SAVE_EXPR) | |
1425 | { | |
1426 | error ("invalid output in `asm'"); | |
1427 | return; | |
1428 | } | |
1429 | } | |
28d81abb | 1430 | |
37366632 | 1431 | output_rtx[i] = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0); |
28d81abb RK |
1432 | } |
1433 | ||
1434 | if (ninputs + noutputs > MAX_RECOG_OPERANDS) | |
1435 | { | |
1436 | error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS); | |
1437 | return; | |
1438 | } | |
1439 | ||
1440 | /* Make vectors for the expression-rtx and constraint strings. */ | |
1441 | ||
1442 | argvec = rtvec_alloc (ninputs); | |
1443 | constraints = rtvec_alloc (ninputs); | |
1444 | ||
1445 | body = gen_rtx (ASM_OPERANDS, VOIDmode, | |
1446 | TREE_STRING_POINTER (string), "", 0, argvec, constraints, | |
1447 | filename, line); | |
1448 | MEM_VOLATILE_P (body) = vol; | |
1449 | ||
1450 | /* Eval the inputs and put them into ARGVEC. | |
1451 | Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */ | |
1452 | ||
1453 | i = 0; | |
1454 | for (tail = inputs; tail; tail = TREE_CHAIN (tail)) | |
1455 | { | |
1456 | int j; | |
1457 | ||
1458 | /* If there's an erroneous arg, emit no insn, | |
1459 | because the ASM_INPUT would get VOIDmode | |
1460 | and that could cause a crash in reload. */ | |
1461 | if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node) | |
1462 | return; | |
1463 | if (TREE_PURPOSE (tail) == NULL_TREE) | |
1464 | { | |
1465 | error ("hard register `%s' listed as input operand to `asm'", | |
1466 | TREE_STRING_POINTER (TREE_VALUE (tail)) ); | |
1467 | return; | |
1468 | } | |
1469 | ||
1470 | /* Make sure constraint has neither `=' nor `+'. */ | |
1471 | ||
1472 | for (j = 0; j < TREE_STRING_LENGTH (TREE_PURPOSE (tail)); j++) | |
1473 | if (TREE_STRING_POINTER (TREE_PURPOSE (tail))[j] == '=' | |
1474 | || TREE_STRING_POINTER (TREE_PURPOSE (tail))[j] == '+') | |
1475 | { | |
1476 | error ("input operand constraint contains `%c'", | |
1477 | TREE_STRING_POINTER (TREE_PURPOSE (tail))[j]); | |
1478 | return; | |
1479 | } | |
1480 | ||
1481 | XVECEXP (body, 3, i) /* argvec */ | |
37366632 | 1482 | = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0); |
28d81abb RK |
1483 | XVECEXP (body, 4, i) /* constraints */ |
1484 | = gen_rtx (ASM_INPUT, TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))), | |
1485 | TREE_STRING_POINTER (TREE_PURPOSE (tail))); | |
1486 | i++; | |
1487 | } | |
1488 | ||
1489 | /* Protect all the operands from the queue, | |
1490 | now that they have all been evaluated. */ | |
1491 | ||
1492 | for (i = 0; i < ninputs; i++) | |
1493 | XVECEXP (body, 3, i) = protect_from_queue (XVECEXP (body, 3, i), 0); | |
1494 | ||
1495 | for (i = 0; i < noutputs; i++) | |
1496 | output_rtx[i] = protect_from_queue (output_rtx[i], 1); | |
1497 | ||
1498 | /* Now, for each output, construct an rtx | |
1499 | (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT | |
1500 | ARGVEC CONSTRAINTS)) | |
1501 | If there is more than one, put them inside a PARALLEL. */ | |
1502 | ||
1503 | if (noutputs == 1 && nclobbers == 0) | |
1504 | { | |
1505 | XSTR (body, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs)); | |
1506 | insn = emit_insn (gen_rtx (SET, VOIDmode, output_rtx[0], body)); | |
1507 | } | |
1508 | else if (noutputs == 0 && nclobbers == 0) | |
1509 | { | |
1510 | /* No output operands: put in a raw ASM_OPERANDS rtx. */ | |
1511 | insn = emit_insn (body); | |
1512 | } | |
1513 | else | |
1514 | { | |
1515 | rtx obody = body; | |
1516 | int num = noutputs; | |
1517 | if (num == 0) num = 1; | |
1518 | body = gen_rtx (PARALLEL, VOIDmode, rtvec_alloc (num + nclobbers)); | |
1519 | ||
1520 | /* For each output operand, store a SET. */ | |
1521 | ||
1522 | for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++) | |
1523 | { | |
1524 | XVECEXP (body, 0, i) | |
1525 | = gen_rtx (SET, VOIDmode, | |
1526 | output_rtx[i], | |
1527 | gen_rtx (ASM_OPERANDS, VOIDmode, | |
1528 | TREE_STRING_POINTER (string), | |
1529 | TREE_STRING_POINTER (TREE_PURPOSE (tail)), | |
1530 | i, argvec, constraints, | |
1531 | filename, line)); | |
1532 | MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol; | |
1533 | } | |
1534 | ||
1535 | /* If there are no outputs (but there are some clobbers) | |
1536 | store the bare ASM_OPERANDS into the PARALLEL. */ | |
1537 | ||
1538 | if (i == 0) | |
1539 | XVECEXP (body, 0, i++) = obody; | |
1540 | ||
1541 | /* Store (clobber REG) for each clobbered register specified. */ | |
1542 | ||
b4ccaa16 | 1543 | for (tail = clobbers; tail; tail = TREE_CHAIN (tail)) |
28d81abb | 1544 | { |
28d81abb | 1545 | char *regname = TREE_STRING_POINTER (TREE_VALUE (tail)); |
b4ac57ab | 1546 | int j = decode_reg_name (regname); |
28d81abb | 1547 | |
b4ac57ab | 1548 | if (j < 0) |
28d81abb | 1549 | { |
c09e6498 | 1550 | if (j == -3) /* `cc', which is not a register */ |
dcfedcd0 RK |
1551 | continue; |
1552 | ||
c09e6498 RS |
1553 | if (j == -4) /* `memory', don't cache memory across asm */ |
1554 | { | |
bffc6177 RS |
1555 | XVECEXP (body, 0, i++) |
1556 | = gen_rtx (CLOBBER, VOIDmode, | |
1557 | gen_rtx (MEM, QImode, | |
1558 | gen_rtx (SCRATCH, VOIDmode, 0))); | |
c09e6498 RS |
1559 | continue; |
1560 | } | |
1561 | ||
28d81abb RK |
1562 | error ("unknown register name `%s' in `asm'", regname); |
1563 | return; | |
1564 | } | |
1565 | ||
1566 | /* Use QImode since that's guaranteed to clobber just one reg. */ | |
b4ccaa16 | 1567 | XVECEXP (body, 0, i++) |
28d81abb RK |
1568 | = gen_rtx (CLOBBER, VOIDmode, gen_rtx (REG, QImode, j)); |
1569 | } | |
1570 | ||
1571 | insn = emit_insn (body); | |
1572 | } | |
1573 | ||
1574 | free_temp_slots (); | |
1575 | } | |
1576 | \f | |
1577 | /* Generate RTL to evaluate the expression EXP | |
1578 | and remember it in case this is the VALUE in a ({... VALUE; }) constr. */ | |
1579 | ||
1580 | void | |
1581 | expand_expr_stmt (exp) | |
1582 | tree exp; | |
1583 | { | |
ca695ac9 JB |
1584 | if (output_bytecode) |
1585 | { | |
1586 | int org_stack_depth = stack_depth; | |
1587 | ||
1588 | bc_expand_expr (exp); | |
1589 | ||
1590 | /* Restore stack depth */ | |
1591 | if (stack_depth < org_stack_depth) | |
1592 | abort (); | |
1593 | ||
1594 | bc_emit_instruction (drop); | |
1595 | ||
1596 | last_expr_type = TREE_TYPE (exp); | |
1597 | return; | |
1598 | } | |
1599 | ||
28d81abb RK |
1600 | /* If -W, warn about statements with no side effects, |
1601 | except for an explicit cast to void (e.g. for assert()), and | |
1602 | except inside a ({...}) where they may be useful. */ | |
1603 | if (expr_stmts_for_value == 0 && exp != error_mark_node) | |
1604 | { | |
1605 | if (! TREE_SIDE_EFFECTS (exp) && (extra_warnings || warn_unused) | |
1606 | && !(TREE_CODE (exp) == CONVERT_EXPR | |
1607 | && TREE_TYPE (exp) == void_type_node)) | |
1608 | warning_with_file_and_line (emit_filename, emit_lineno, | |
1609 | "statement with no effect"); | |
1610 | else if (warn_unused) | |
1611 | warn_if_unused_value (exp); | |
1612 | } | |
1613 | last_expr_type = TREE_TYPE (exp); | |
1614 | if (! flag_syntax_only) | |
37366632 RK |
1615 | last_expr_value = expand_expr (exp, |
1616 | (expr_stmts_for_value | |
1617 | ? NULL_RTX : const0_rtx), | |
28d81abb RK |
1618 | VOIDmode, 0); |
1619 | ||
1620 | /* If all we do is reference a volatile value in memory, | |
1621 | copy it to a register to be sure it is actually touched. */ | |
1622 | if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM | |
1623 | && TREE_THIS_VOLATILE (exp)) | |
1624 | { | |
6a5bbbe6 RS |
1625 | if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode) |
1626 | ; | |
1627 | else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode) | |
28d81abb RK |
1628 | copy_to_reg (last_expr_value); |
1629 | else | |
ddbe9812 RS |
1630 | { |
1631 | rtx lab = gen_label_rtx (); | |
1632 | ||
1633 | /* Compare the value with itself to reference it. */ | |
1634 | emit_cmp_insn (last_expr_value, last_expr_value, EQ, | |
1635 | expand_expr (TYPE_SIZE (last_expr_type), | |
37366632 | 1636 | NULL_RTX, VOIDmode, 0), |
ddbe9812 RS |
1637 | BLKmode, 0, |
1638 | TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT); | |
1639 | emit_jump_insn ((*bcc_gen_fctn[(int) EQ]) (lab)); | |
1640 | emit_label (lab); | |
1641 | } | |
28d81abb RK |
1642 | } |
1643 | ||
1644 | /* If this expression is part of a ({...}) and is in memory, we may have | |
1645 | to preserve temporaries. */ | |
1646 | preserve_temp_slots (last_expr_value); | |
1647 | ||
1648 | /* Free any temporaries used to evaluate this expression. Any temporary | |
1649 | used as a result of this expression will already have been preserved | |
1650 | above. */ | |
1651 | free_temp_slots (); | |
1652 | ||
1653 | emit_queue (); | |
1654 | } | |
1655 | ||
1656 | /* Warn if EXP contains any computations whose results are not used. | |
1657 | Return 1 if a warning is printed; 0 otherwise. */ | |
1658 | ||
1659 | static int | |
1660 | warn_if_unused_value (exp) | |
1661 | tree exp; | |
1662 | { | |
1663 | if (TREE_USED (exp)) | |
1664 | return 0; | |
1665 | ||
1666 | switch (TREE_CODE (exp)) | |
1667 | { | |
1668 | case PREINCREMENT_EXPR: | |
1669 | case POSTINCREMENT_EXPR: | |
1670 | case PREDECREMENT_EXPR: | |
1671 | case POSTDECREMENT_EXPR: | |
1672 | case MODIFY_EXPR: | |
1673 | case INIT_EXPR: | |
1674 | case TARGET_EXPR: | |
1675 | case CALL_EXPR: | |
1676 | case METHOD_CALL_EXPR: | |
1677 | case RTL_EXPR: | |
28d81abb RK |
1678 | case WITH_CLEANUP_EXPR: |
1679 | case EXIT_EXPR: | |
1680 | /* We don't warn about COND_EXPR because it may be a useful | |
1681 | construct if either arm contains a side effect. */ | |
1682 | case COND_EXPR: | |
1683 | return 0; | |
1684 | ||
1685 | case BIND_EXPR: | |
1686 | /* For a binding, warn if no side effect within it. */ | |
1687 | return warn_if_unused_value (TREE_OPERAND (exp, 1)); | |
1688 | ||
1689 | case TRUTH_ORIF_EXPR: | |
1690 | case TRUTH_ANDIF_EXPR: | |
1691 | /* In && or ||, warn if 2nd operand has no side effect. */ | |
1692 | return warn_if_unused_value (TREE_OPERAND (exp, 1)); | |
1693 | ||
1694 | case COMPOUND_EXPR: | |
1695 | if (warn_if_unused_value (TREE_OPERAND (exp, 0))) | |
1696 | return 1; | |
4d23e509 RS |
1697 | /* Let people do `(foo (), 0)' without a warning. */ |
1698 | if (TREE_CONSTANT (TREE_OPERAND (exp, 1))) | |
1699 | return 0; | |
28d81abb RK |
1700 | return warn_if_unused_value (TREE_OPERAND (exp, 1)); |
1701 | ||
1702 | case NOP_EXPR: | |
1703 | case CONVERT_EXPR: | |
b4ac57ab | 1704 | case NON_LVALUE_EXPR: |
28d81abb RK |
1705 | /* Don't warn about values cast to void. */ |
1706 | if (TREE_TYPE (exp) == void_type_node) | |
1707 | return 0; | |
1708 | /* Don't warn about conversions not explicit in the user's program. */ | |
1709 | if (TREE_NO_UNUSED_WARNING (exp)) | |
1710 | return 0; | |
1711 | /* Assignment to a cast usually results in a cast of a modify. | |
1712 | Don't complain about that. */ | |
1713 | if (TREE_CODE (TREE_OPERAND (exp, 0)) == MODIFY_EXPR) | |
1714 | return 0; | |
1715 | /* Sometimes it results in a cast of a cast of a modify. | |
1716 | Don't complain about that. */ | |
1717 | if ((TREE_CODE (TREE_OPERAND (exp, 0)) == CONVERT_EXPR | |
1718 | || TREE_CODE (TREE_OPERAND (exp, 0)) == NOP_EXPR) | |
1719 | && TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0)) == MODIFY_EXPR) | |
1720 | return 0; | |
1721 | ||
1722 | default: | |
ddbe9812 RS |
1723 | /* Referencing a volatile value is a side effect, so don't warn. */ |
1724 | if ((TREE_CODE_CLASS (TREE_CODE (exp)) == 'd' | |
1725 | || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r') | |
1726 | && TREE_THIS_VOLATILE (exp)) | |
1727 | return 0; | |
28d81abb RK |
1728 | warning_with_file_and_line (emit_filename, emit_lineno, |
1729 | "value computed is not used"); | |
1730 | return 1; | |
1731 | } | |
1732 | } | |
1733 | ||
1734 | /* Clear out the memory of the last expression evaluated. */ | |
1735 | ||
1736 | void | |
1737 | clear_last_expr () | |
1738 | { | |
1739 | last_expr_type = 0; | |
1740 | } | |
1741 | ||
1742 | /* Begin a statement which will return a value. | |
1743 | Return the RTL_EXPR for this statement expr. | |
1744 | The caller must save that value and pass it to expand_end_stmt_expr. */ | |
1745 | ||
1746 | tree | |
1747 | expand_start_stmt_expr () | |
1748 | { | |
ca695ac9 JB |
1749 | int momentary; |
1750 | tree t; | |
1751 | ||
1752 | /* When generating bytecode just note down the stack depth */ | |
1753 | if (output_bytecode) | |
1754 | return (build_int_2 (stack_depth, 0)); | |
1755 | ||
28d81abb RK |
1756 | /* Make the RTL_EXPR node temporary, not momentary, |
1757 | so that rtl_expr_chain doesn't become garbage. */ | |
ca695ac9 JB |
1758 | momentary = suspend_momentary (); |
1759 | t = make_node (RTL_EXPR); | |
28d81abb RK |
1760 | resume_momentary (momentary); |
1761 | start_sequence (); | |
1762 | NO_DEFER_POP; | |
1763 | expr_stmts_for_value++; | |
1764 | return t; | |
1765 | } | |
1766 | ||
1767 | /* Restore the previous state at the end of a statement that returns a value. | |
1768 | Returns a tree node representing the statement's value and the | |
1769 | insns to compute the value. | |
1770 | ||
1771 | The nodes of that expression have been freed by now, so we cannot use them. | |
1772 | But we don't want to do that anyway; the expression has already been | |
1773 | evaluated and now we just want to use the value. So generate a RTL_EXPR | |
1774 | with the proper type and RTL value. | |
1775 | ||
1776 | If the last substatement was not an expression, | |
1777 | return something with type `void'. */ | |
1778 | ||
1779 | tree | |
1780 | expand_end_stmt_expr (t) | |
1781 | tree t; | |
1782 | { | |
ca695ac9 JB |
1783 | if (output_bytecode) |
1784 | { | |
1785 | int i; | |
1786 | tree t; | |
1787 | ||
1788 | ||
1789 | /* At this point, all expressions have been evaluated in order. | |
1790 | However, all expression values have been popped when evaluated, | |
1791 | which means we have to recover the last expression value. This is | |
1792 | the last value removed by means of a `drop' instruction. Instead | |
1793 | of adding code to inhibit dropping the last expression value, it | |
1794 | is here recovered by undoing the `drop'. Since `drop' is | |
1795 | equivalent to `adjustackSI [1]', it can be undone with `adjstackSI | |
1796 | [-1]'. */ | |
1797 | ||
1798 | bc_adjust_stack (-1); | |
1799 | ||
1800 | if (!last_expr_type) | |
1801 | last_expr_type = void_type_node; | |
1802 | ||
1803 | t = make_node (RTL_EXPR); | |
1804 | TREE_TYPE (t) = last_expr_type; | |
1805 | RTL_EXPR_RTL (t) = NULL; | |
1806 | RTL_EXPR_SEQUENCE (t) = NULL; | |
1807 | ||
1808 | /* Don't consider deleting this expr or containing exprs at tree level. */ | |
1809 | TREE_THIS_VOLATILE (t) = 1; | |
1810 | ||
1811 | last_expr_type = 0; | |
1812 | return t; | |
1813 | } | |
1814 | ||
28d81abb RK |
1815 | OK_DEFER_POP; |
1816 | ||
1817 | if (last_expr_type == 0) | |
1818 | { | |
1819 | last_expr_type = void_type_node; | |
1820 | last_expr_value = const0_rtx; | |
1821 | } | |
1822 | else if (last_expr_value == 0) | |
1823 | /* There are some cases where this can happen, such as when the | |
1824 | statement is void type. */ | |
1825 | last_expr_value = const0_rtx; | |
1826 | else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value)) | |
1827 | /* Remove any possible QUEUED. */ | |
1828 | last_expr_value = protect_from_queue (last_expr_value, 0); | |
1829 | ||
1830 | emit_queue (); | |
1831 | ||
1832 | TREE_TYPE (t) = last_expr_type; | |
1833 | RTL_EXPR_RTL (t) = last_expr_value; | |
1834 | RTL_EXPR_SEQUENCE (t) = get_insns (); | |
1835 | ||
1836 | rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain); | |
1837 | ||
1838 | end_sequence (); | |
1839 | ||
1840 | /* Don't consider deleting this expr or containing exprs at tree level. */ | |
1841 | TREE_SIDE_EFFECTS (t) = 1; | |
1842 | /* Propagate volatility of the actual RTL expr. */ | |
1843 | TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value); | |
1844 | ||
1845 | last_expr_type = 0; | |
1846 | expr_stmts_for_value--; | |
1847 | ||
1848 | return t; | |
1849 | } | |
1850 | \f | |
1851 | /* The exception handling nesting looks like this: | |
1852 | ||
1853 | <-- Level N-1 | |
1854 | { <-- exception handler block | |
1855 | <-- Level N | |
1856 | <-- in an exception handler | |
1857 | { <-- try block | |
1858 | : <-- in a TRY block | |
1859 | : <-- in an exception handler | |
1860 | : | |
1861 | } | |
1862 | ||
1863 | { <-- except block | |
1864 | : <-- in an except block | |
1865 | : <-- in an exception handler | |
1866 | : | |
1867 | } | |
1868 | ||
1869 | } | |
a124fd5e | 1870 | */ |
28d81abb RK |
1871 | |
1872 | /* Return nonzero iff in a try block at level LEVEL. */ | |
1873 | ||
1874 | int | |
1875 | in_try_block (level) | |
1876 | int level; | |
1877 | { | |
1878 | struct nesting *n = except_stack; | |
1879 | while (1) | |
1880 | { | |
1881 | while (n && n->data.except_stmt.after_label != 0) | |
1882 | n = n->next; | |
1883 | if (n == 0) | |
1884 | return 0; | |
1885 | if (level == 0) | |
1886 | return n != 0; | |
1887 | level--; | |
1888 | n = n->next; | |
1889 | } | |
1890 | } | |
1891 | ||
1892 | /* Return nonzero iff in an except block at level LEVEL. */ | |
1893 | ||
1894 | int | |
1895 | in_except_block (level) | |
1896 | int level; | |
1897 | { | |
1898 | struct nesting *n = except_stack; | |
1899 | while (1) | |
1900 | { | |
1901 | while (n && n->data.except_stmt.after_label == 0) | |
1902 | n = n->next; | |
1903 | if (n == 0) | |
1904 | return 0; | |
1905 | if (level == 0) | |
1906 | return n != 0; | |
1907 | level--; | |
1908 | n = n->next; | |
1909 | } | |
1910 | } | |
1911 | ||
1912 | /* Return nonzero iff in an exception handler at level LEVEL. */ | |
1913 | ||
1914 | int | |
1915 | in_exception_handler (level) | |
1916 | int level; | |
1917 | { | |
1918 | struct nesting *n = except_stack; | |
1919 | while (n && level--) | |
1920 | n = n->next; | |
1921 | return n != 0; | |
1922 | } | |
1923 | ||
1924 | /* Record the fact that the current exception nesting raises | |
1925 | exception EX. If not in an exception handler, return 0. */ | |
1926 | int | |
1927 | expand_raise (ex) | |
1928 | tree ex; | |
1929 | { | |
1930 | tree *raises_ptr; | |
1931 | ||
1932 | if (except_stack == 0) | |
1933 | return 0; | |
1934 | raises_ptr = &except_stack->data.except_stmt.raised; | |
1935 | if (! value_member (ex, *raises_ptr)) | |
1936 | *raises_ptr = tree_cons (NULL_TREE, ex, *raises_ptr); | |
1937 | return 1; | |
1938 | } | |
1939 | ||
1940 | /* Generate RTL for the start of a try block. | |
1941 | ||
1942 | TRY_CLAUSE is the condition to test to enter the try block. */ | |
1943 | ||
1944 | void | |
1945 | expand_start_try (try_clause, exitflag, escapeflag) | |
1946 | tree try_clause; | |
1947 | int exitflag; | |
1948 | int escapeflag; | |
1949 | { | |
1950 | struct nesting *thishandler = ALLOC_NESTING (); | |
1951 | ||
1952 | /* Make an entry on cond_stack for the cond we are entering. */ | |
1953 | ||
1954 | thishandler->next = except_stack; | |
1955 | thishandler->all = nesting_stack; | |
1956 | thishandler->depth = ++nesting_depth; | |
1957 | thishandler->data.except_stmt.raised = 0; | |
1958 | thishandler->data.except_stmt.handled = 0; | |
1959 | thishandler->data.except_stmt.first_insn = get_insns (); | |
1960 | thishandler->data.except_stmt.except_label = gen_label_rtx (); | |
1961 | thishandler->data.except_stmt.unhandled_label = 0; | |
1962 | thishandler->data.except_stmt.after_label = 0; | |
1963 | thishandler->data.except_stmt.escape_label | |
1964 | = escapeflag ? thishandler->data.except_stmt.except_label : 0; | |
1965 | thishandler->exit_label = exitflag ? gen_label_rtx () : 0; | |
1966 | except_stack = thishandler; | |
1967 | nesting_stack = thishandler; | |
1968 | ||
37366632 | 1969 | do_jump (try_clause, thishandler->data.except_stmt.except_label, NULL_RTX); |
28d81abb RK |
1970 | } |
1971 | ||
1972 | /* End of a TRY block. Nothing to do for now. */ | |
1973 | ||
1974 | void | |
1975 | expand_end_try () | |
1976 | { | |
1977 | except_stack->data.except_stmt.after_label = gen_label_rtx (); | |
37366632 RK |
1978 | expand_goto_internal (NULL_TREE, except_stack->data.except_stmt.after_label, |
1979 | NULL_RTX); | |
28d81abb RK |
1980 | } |
1981 | ||
1982 | /* Start an `except' nesting contour. | |
1983 | EXITFLAG says whether this contour should be able to `exit' something. | |
1984 | ESCAPEFLAG says whether this contour should be escapable. */ | |
1985 | ||
1986 | void | |
1987 | expand_start_except (exitflag, escapeflag) | |
1988 | int exitflag; | |
1989 | int escapeflag; | |
1990 | { | |
1991 | if (exitflag) | |
1992 | { | |
1993 | struct nesting *n; | |
1994 | /* An `exit' from catch clauses goes out to next exit level, | |
1995 | if there is one. Otherwise, it just goes to the end | |
1996 | of the construct. */ | |
1997 | for (n = except_stack->next; n; n = n->next) | |
1998 | if (n->exit_label != 0) | |
1999 | { | |
2000 | except_stack->exit_label = n->exit_label; | |
2001 | break; | |
2002 | } | |
2003 | if (n == 0) | |
2004 | except_stack->exit_label = except_stack->data.except_stmt.after_label; | |
2005 | } | |
2006 | if (escapeflag) | |
2007 | { | |
2008 | struct nesting *n; | |
2009 | /* An `escape' from catch clauses goes out to next escape level, | |
2010 | if there is one. Otherwise, it just goes to the end | |
2011 | of the construct. */ | |
2012 | for (n = except_stack->next; n; n = n->next) | |
2013 | if (n->data.except_stmt.escape_label != 0) | |
2014 | { | |
2015 | except_stack->data.except_stmt.escape_label | |
2016 | = n->data.except_stmt.escape_label; | |
2017 | break; | |
2018 | } | |
2019 | if (n == 0) | |
2020 | except_stack->data.except_stmt.escape_label | |
2021 | = except_stack->data.except_stmt.after_label; | |
2022 | } | |
2023 | do_pending_stack_adjust (); | |
2024 | emit_label (except_stack->data.except_stmt.except_label); | |
2025 | } | |
2026 | ||
2027 | /* Generate code to `escape' from an exception contour. This | |
2028 | is like `exiting', but does not conflict with constructs which | |
2029 | use `exit_label'. | |
2030 | ||
2031 | Return nonzero if this contour is escapable, otherwise | |
2032 | return zero, and language-specific code will emit the | |
2033 | appropriate error message. */ | |
2034 | int | |
2035 | expand_escape_except () | |
2036 | { | |
2037 | struct nesting *n; | |
2038 | last_expr_type = 0; | |
2039 | for (n = except_stack; n; n = n->next) | |
2040 | if (n->data.except_stmt.escape_label != 0) | |
2041 | { | |
37366632 RK |
2042 | expand_goto_internal (NULL_TREE, |
2043 | n->data.except_stmt.escape_label, NULL_RTX); | |
28d81abb RK |
2044 | return 1; |
2045 | } | |
2046 | ||
2047 | return 0; | |
2048 | } | |
2049 | ||
2050 | /* Finish processing and `except' contour. | |
2051 | Culls out all exceptions which might be raise but not | |
2052 | handled, and returns the list to the caller. | |
2053 | Language-specific code is responsible for dealing with these | |
2054 | exceptions. */ | |
2055 | ||
2056 | tree | |
2057 | expand_end_except () | |
2058 | { | |
2059 | struct nesting *n; | |
2060 | tree raised = NULL_TREE; | |
2061 | ||
2062 | do_pending_stack_adjust (); | |
2063 | emit_label (except_stack->data.except_stmt.after_label); | |
2064 | ||
2065 | n = except_stack->next; | |
2066 | if (n) | |
2067 | { | |
2068 | /* Propagate exceptions raised but not handled to next | |
2069 | highest level. */ | |
2070 | tree handled = except_stack->data.except_stmt.raised; | |
2071 | if (handled != void_type_node) | |
2072 | { | |
2073 | tree prev = NULL_TREE; | |
2074 | raised = except_stack->data.except_stmt.raised; | |
2075 | while (handled) | |
2076 | { | |
2077 | tree this_raise; | |
2078 | for (this_raise = raised, prev = 0; this_raise; | |
2079 | this_raise = TREE_CHAIN (this_raise)) | |
2080 | { | |
2081 | if (value_member (TREE_VALUE (this_raise), handled)) | |
2082 | { | |
2083 | if (prev) | |
2084 | TREE_CHAIN (prev) = TREE_CHAIN (this_raise); | |
2085 | else | |
2086 | { | |
2087 | raised = TREE_CHAIN (raised); | |
2088 | if (raised == NULL_TREE) | |
2089 | goto nada; | |
2090 | } | |
2091 | } | |
2092 | else | |
2093 | prev = this_raise; | |
2094 | } | |
2095 | handled = TREE_CHAIN (handled); | |
2096 | } | |
2097 | if (prev == NULL_TREE) | |
2098 | prev = raised; | |
2099 | if (prev) | |
2100 | TREE_CHAIN (prev) = n->data.except_stmt.raised; | |
2101 | nada: | |
2102 | n->data.except_stmt.raised = raised; | |
2103 | } | |
2104 | } | |
2105 | ||
2106 | POPSTACK (except_stack); | |
2107 | last_expr_type = 0; | |
2108 | return raised; | |
2109 | } | |
2110 | ||
2111 | /* Record that exception EX is caught by this exception handler. | |
2112 | Return nonzero if in exception handling construct, otherwise return 0. */ | |
2113 | int | |
2114 | expand_catch (ex) | |
2115 | tree ex; | |
2116 | { | |
2117 | tree *raises_ptr; | |
2118 | ||
2119 | if (except_stack == 0) | |
2120 | return 0; | |
2121 | raises_ptr = &except_stack->data.except_stmt.handled; | |
2122 | if (*raises_ptr != void_type_node | |
2123 | && ex != NULL_TREE | |
2124 | && ! value_member (ex, *raises_ptr)) | |
2125 | *raises_ptr = tree_cons (NULL_TREE, ex, *raises_ptr); | |
2126 | return 1; | |
2127 | } | |
2128 | ||
2129 | /* Record that this exception handler catches all exceptions. | |
2130 | Return nonzero if in exception handling construct, otherwise return 0. */ | |
2131 | ||
2132 | int | |
2133 | expand_catch_default () | |
2134 | { | |
2135 | if (except_stack == 0) | |
2136 | return 0; | |
2137 | except_stack->data.except_stmt.handled = void_type_node; | |
2138 | return 1; | |
2139 | } | |
2140 | ||
2141 | int | |
2142 | expand_end_catch () | |
2143 | { | |
2144 | if (except_stack == 0 || except_stack->data.except_stmt.after_label == 0) | |
2145 | return 0; | |
37366632 RK |
2146 | expand_goto_internal (NULL_TREE, except_stack->data.except_stmt.after_label, |
2147 | NULL_RTX); | |
28d81abb RK |
2148 | return 1; |
2149 | } | |
2150 | \f | |
2151 | /* Generate RTL for the start of an if-then. COND is the expression | |
2152 | whose truth should be tested. | |
2153 | ||
2154 | If EXITFLAG is nonzero, this conditional is visible to | |
2155 | `exit_something'. */ | |
2156 | ||
2157 | void | |
2158 | expand_start_cond (cond, exitflag) | |
2159 | tree cond; | |
2160 | int exitflag; | |
2161 | { | |
2162 | struct nesting *thiscond = ALLOC_NESTING (); | |
2163 | ||
2164 | /* Make an entry on cond_stack for the cond we are entering. */ | |
2165 | ||
2166 | thiscond->next = cond_stack; | |
2167 | thiscond->all = nesting_stack; | |
2168 | thiscond->depth = ++nesting_depth; | |
2169 | thiscond->data.cond.next_label = gen_label_rtx (); | |
2170 | /* Before we encounter an `else', we don't need a separate exit label | |
2171 | unless there are supposed to be exit statements | |
2172 | to exit this conditional. */ | |
2173 | thiscond->exit_label = exitflag ? gen_label_rtx () : 0; | |
2174 | thiscond->data.cond.endif_label = thiscond->exit_label; | |
2175 | cond_stack = thiscond; | |
2176 | nesting_stack = thiscond; | |
2177 | ||
ca695ac9 JB |
2178 | if (output_bytecode) |
2179 | bc_expand_start_cond (cond, exitflag); | |
2180 | else | |
2181 | do_jump (cond, thiscond->data.cond.next_label, NULL_RTX); | |
28d81abb RK |
2182 | } |
2183 | ||
2184 | /* Generate RTL between then-clause and the elseif-clause | |
2185 | of an if-then-elseif-.... */ | |
2186 | ||
2187 | void | |
2188 | expand_start_elseif (cond) | |
2189 | tree cond; | |
2190 | { | |
2191 | if (cond_stack->data.cond.endif_label == 0) | |
2192 | cond_stack->data.cond.endif_label = gen_label_rtx (); | |
2193 | emit_jump (cond_stack->data.cond.endif_label); | |
2194 | emit_label (cond_stack->data.cond.next_label); | |
2195 | cond_stack->data.cond.next_label = gen_label_rtx (); | |
37366632 | 2196 | do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX); |
28d81abb RK |
2197 | } |
2198 | ||
2199 | /* Generate RTL between the then-clause and the else-clause | |
2200 | of an if-then-else. */ | |
2201 | ||
2202 | void | |
2203 | expand_start_else () | |
2204 | { | |
2205 | if (cond_stack->data.cond.endif_label == 0) | |
2206 | cond_stack->data.cond.endif_label = gen_label_rtx (); | |
ca695ac9 JB |
2207 | |
2208 | if (output_bytecode) | |
2209 | { | |
2210 | bc_expand_start_else (); | |
2211 | return; | |
2212 | } | |
2213 | ||
28d81abb RK |
2214 | emit_jump (cond_stack->data.cond.endif_label); |
2215 | emit_label (cond_stack->data.cond.next_label); | |
2216 | cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */ | |
2217 | } | |
2218 | ||
2219 | /* Generate RTL for the end of an if-then. | |
2220 | Pop the record for it off of cond_stack. */ | |
2221 | ||
2222 | void | |
2223 | expand_end_cond () | |
2224 | { | |
2225 | struct nesting *thiscond = cond_stack; | |
2226 | ||
ca695ac9 JB |
2227 | if (output_bytecode) |
2228 | bc_expand_end_cond (); | |
2229 | else | |
2230 | { | |
2231 | do_pending_stack_adjust (); | |
2232 | if (thiscond->data.cond.next_label) | |
2233 | emit_label (thiscond->data.cond.next_label); | |
2234 | if (thiscond->data.cond.endif_label) | |
2235 | emit_label (thiscond->data.cond.endif_label); | |
2236 | } | |
28d81abb RK |
2237 | |
2238 | POPSTACK (cond_stack); | |
2239 | last_expr_type = 0; | |
2240 | } | |
ca695ac9 JB |
2241 | |
2242 | ||
2243 | /* Generate code for the start of an if-then. COND is the expression | |
2244 | whose truth is to be tested; if EXITFLAG is nonzero this conditional | |
2245 | is to be visible to exit_something. It is assumed that the caller | |
2246 | has pushed the previous context on the cond stack. */ | |
2247 | void | |
2248 | bc_expand_start_cond (cond, exitflag) | |
2249 | tree cond; | |
2250 | int exitflag; | |
2251 | { | |
2252 | struct nesting *thiscond = cond_stack; | |
2253 | ||
2254 | thiscond->data.case_stmt.nominal_type = cond; | |
2255 | bc_expand_expr (cond); | |
c3a2235b | 2256 | bc_emit_bytecode (xjumpifnot); |
c53e9440 | 2257 | bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscond->exit_label)); |
ca695ac9 JB |
2258 | |
2259 | #ifdef DEBUG_PRINT_CODE | |
2260 | fputc ('\n', stderr); | |
2261 | #endif | |
2262 | } | |
2263 | ||
2264 | /* Generate the label for the end of an if with | |
2265 | no else- clause. */ | |
2266 | void | |
2267 | bc_expand_end_cond () | |
2268 | { | |
2269 | struct nesting *thiscond = cond_stack; | |
2270 | ||
c53e9440 | 2271 | bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscond->exit_label)); |
ca695ac9 JB |
2272 | } |
2273 | ||
2274 | /* Generate code for the start of the else- clause of | |
2275 | an if-then-else. */ | |
2276 | void | |
2277 | bc_expand_start_else () | |
2278 | { | |
2279 | struct nesting *thiscond = cond_stack; | |
2280 | ||
2281 | thiscond->data.cond.endif_label = thiscond->exit_label; | |
2282 | thiscond->exit_label = gen_label_rtx (); | |
2283 | bc_emit_bytecode (jump); | |
c53e9440 | 2284 | bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscond->exit_label)); |
ca695ac9 JB |
2285 | |
2286 | #ifdef DEBUG_PRINT_CODE | |
2287 | fputc ('\n', stderr); | |
2288 | #endif | |
2289 | ||
c53e9440 | 2290 | bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscond->data.cond.endif_label)); |
ca695ac9 | 2291 | } |
28d81abb RK |
2292 | \f |
2293 | /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this | |
2294 | loop should be exited by `exit_something'. This is a loop for which | |
2295 | `expand_continue' will jump to the top of the loop. | |
2296 | ||
2297 | Make an entry on loop_stack to record the labels associated with | |
2298 | this loop. */ | |
2299 | ||
2300 | struct nesting * | |
2301 | expand_start_loop (exit_flag) | |
2302 | int exit_flag; | |
2303 | { | |
2304 | register struct nesting *thisloop = ALLOC_NESTING (); | |
2305 | ||
2306 | /* Make an entry on loop_stack for the loop we are entering. */ | |
2307 | ||
2308 | thisloop->next = loop_stack; | |
2309 | thisloop->all = nesting_stack; | |
2310 | thisloop->depth = ++nesting_depth; | |
2311 | thisloop->data.loop.start_label = gen_label_rtx (); | |
2312 | thisloop->data.loop.end_label = gen_label_rtx (); | |
2313 | thisloop->data.loop.continue_label = thisloop->data.loop.start_label; | |
2314 | thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0; | |
2315 | loop_stack = thisloop; | |
2316 | nesting_stack = thisloop; | |
2317 | ||
ca695ac9 JB |
2318 | if (output_bytecode) |
2319 | { | |
c53e9440 | 2320 | bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisloop->data.loop.start_label)); |
ca695ac9 JB |
2321 | return thisloop; |
2322 | } | |
2323 | ||
28d81abb RK |
2324 | do_pending_stack_adjust (); |
2325 | emit_queue (); | |
37366632 | 2326 | emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG); |
28d81abb RK |
2327 | emit_label (thisloop->data.loop.start_label); |
2328 | ||
2329 | return thisloop; | |
2330 | } | |
2331 | ||
2332 | /* Like expand_start_loop but for a loop where the continuation point | |
2333 | (for expand_continue_loop) will be specified explicitly. */ | |
2334 | ||
2335 | struct nesting * | |
2336 | expand_start_loop_continue_elsewhere (exit_flag) | |
2337 | int exit_flag; | |
2338 | { | |
2339 | struct nesting *thisloop = expand_start_loop (exit_flag); | |
2340 | loop_stack->data.loop.continue_label = gen_label_rtx (); | |
2341 | return thisloop; | |
2342 | } | |
2343 | ||
2344 | /* Specify the continuation point for a loop started with | |
2345 | expand_start_loop_continue_elsewhere. | |
2346 | Use this at the point in the code to which a continue statement | |
2347 | should jump. */ | |
2348 | ||
2349 | void | |
2350 | expand_loop_continue_here () | |
2351 | { | |
ca695ac9 JB |
2352 | if (output_bytecode) |
2353 | { | |
c53e9440 | 2354 | bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (loop_stack->data.loop.continue_label)); |
ca695ac9 JB |
2355 | return; |
2356 | } | |
28d81abb | 2357 | do_pending_stack_adjust (); |
37366632 | 2358 | emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT); |
28d81abb RK |
2359 | emit_label (loop_stack->data.loop.continue_label); |
2360 | } | |
2361 | ||
ca695ac9 JB |
2362 | /* End a loop. */ |
2363 | static void | |
2364 | bc_expand_end_loop () | |
2365 | { | |
2366 | struct nesting *thisloop = loop_stack; | |
2367 | ||
2368 | bc_emit_bytecode (jump); | |
c53e9440 | 2369 | bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thisloop->data.loop.start_label)); |
ca695ac9 JB |
2370 | |
2371 | #ifdef DEBUG_PRINT_CODE | |
2372 | fputc ('\n', stderr); | |
2373 | #endif | |
2374 | ||
c53e9440 | 2375 | bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisloop->exit_label)); |
ca695ac9 JB |
2376 | POPSTACK (loop_stack); |
2377 | last_expr_type = 0; | |
2378 | } | |
2379 | ||
2380 | ||
28d81abb RK |
2381 | /* Finish a loop. Generate a jump back to the top and the loop-exit label. |
2382 | Pop the block off of loop_stack. */ | |
2383 | ||
2384 | void | |
2385 | expand_end_loop () | |
2386 | { | |
ca695ac9 JB |
2387 | register rtx insn; |
2388 | register rtx start_label; | |
28d81abb RK |
2389 | rtx last_test_insn = 0; |
2390 | int num_insns = 0; | |
ca695ac9 JB |
2391 | |
2392 | if (output_bytecode) | |
2393 | { | |
2394 | bc_expand_end_loop (); | |
2395 | return; | |
2396 | } | |
2397 | ||
2398 | insn = get_last_insn (); | |
2399 | start_label = loop_stack->data.loop.start_label; | |
28d81abb RK |
2400 | |
2401 | /* Mark the continue-point at the top of the loop if none elsewhere. */ | |
2402 | if (start_label == loop_stack->data.loop.continue_label) | |
2403 | emit_note_before (NOTE_INSN_LOOP_CONT, start_label); | |
2404 | ||
2405 | do_pending_stack_adjust (); | |
2406 | ||
2407 | /* If optimizing, perhaps reorder the loop. If the loop | |
2408 | starts with a conditional exit, roll that to the end | |
2409 | where it will optimize together with the jump back. | |
2410 | ||
2411 | We look for the last conditional branch to the exit that we encounter | |
2412 | before hitting 30 insns or a CALL_INSN. If we see an unconditional | |
2413 | branch to the exit first, use it. | |
2414 | ||
2415 | We must also stop at NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes | |
2416 | because moving them is not valid. */ | |
2417 | ||
2418 | if (optimize | |
2419 | && | |
2420 | ! (GET_CODE (insn) == JUMP_INSN | |
2421 | && GET_CODE (PATTERN (insn)) == SET | |
2422 | && SET_DEST (PATTERN (insn)) == pc_rtx | |
2423 | && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE)) | |
2424 | { | |
2425 | /* Scan insns from the top of the loop looking for a qualified | |
2426 | conditional exit. */ | |
2427 | for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn; | |
2428 | insn = NEXT_INSN (insn)) | |
2429 | { | |
2430 | if (GET_CODE (insn) == CALL_INSN || GET_CODE (insn) == CODE_LABEL) | |
2431 | break; | |
2432 | ||
2433 | if (GET_CODE (insn) == NOTE | |
2434 | && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG | |
2435 | || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)) | |
2436 | break; | |
2437 | ||
2438 | if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN) | |
2439 | num_insns++; | |
2440 | ||
2441 | if (last_test_insn && num_insns > 30) | |
2442 | break; | |
2443 | ||
2444 | if (GET_CODE (insn) == JUMP_INSN && GET_CODE (PATTERN (insn)) == SET | |
2445 | && SET_DEST (PATTERN (insn)) == pc_rtx | |
2446 | && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE | |
2447 | && ((GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 1)) == LABEL_REF | |
2448 | && (XEXP (XEXP (SET_SRC (PATTERN (insn)), 1), 0) | |
2449 | == loop_stack->data.loop.end_label)) | |
2450 | || (GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 2)) == LABEL_REF | |
2451 | && (XEXP (XEXP (SET_SRC (PATTERN (insn)), 2), 0) | |
2452 | == loop_stack->data.loop.end_label)))) | |
2453 | last_test_insn = insn; | |
2454 | ||
2455 | if (last_test_insn == 0 && GET_CODE (insn) == JUMP_INSN | |
2456 | && GET_CODE (PATTERN (insn)) == SET | |
2457 | && SET_DEST (PATTERN (insn)) == pc_rtx | |
2458 | && GET_CODE (SET_SRC (PATTERN (insn))) == LABEL_REF | |
2459 | && (XEXP (SET_SRC (PATTERN (insn)), 0) | |
2460 | == loop_stack->data.loop.end_label)) | |
2461 | /* Include BARRIER. */ | |
2462 | last_test_insn = NEXT_INSN (insn); | |
2463 | } | |
2464 | ||
2465 | if (last_test_insn != 0 && last_test_insn != get_last_insn ()) | |
2466 | { | |
2467 | /* We found one. Move everything from there up | |
2468 | to the end of the loop, and add a jump into the loop | |
2469 | to jump to there. */ | |
2470 | register rtx newstart_label = gen_label_rtx (); | |
2471 | register rtx start_move = start_label; | |
2472 | ||
b4ac57ab | 2473 | /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note, |
28d81abb RK |
2474 | then we want to move this note also. */ |
2475 | if (GET_CODE (PREV_INSN (start_move)) == NOTE | |
2476 | && (NOTE_LINE_NUMBER (PREV_INSN (start_move)) | |
2477 | == NOTE_INSN_LOOP_CONT)) | |
2478 | start_move = PREV_INSN (start_move); | |
2479 | ||
2480 | emit_label_after (newstart_label, PREV_INSN (start_move)); | |
2481 | reorder_insns (start_move, last_test_insn, get_last_insn ()); | |
2482 | emit_jump_insn_after (gen_jump (start_label), | |
2483 | PREV_INSN (newstart_label)); | |
2484 | emit_barrier_after (PREV_INSN (newstart_label)); | |
2485 | start_label = newstart_label; | |
2486 | } | |
2487 | } | |
2488 | ||
2489 | emit_jump (start_label); | |
37366632 | 2490 | emit_note (NULL_PTR, NOTE_INSN_LOOP_END); |
28d81abb RK |
2491 | emit_label (loop_stack->data.loop.end_label); |
2492 | ||
2493 | POPSTACK (loop_stack); | |
2494 | ||
2495 | last_expr_type = 0; | |
2496 | } | |
2497 | ||
2498 | /* Generate a jump to the current loop's continue-point. | |
2499 | This is usually the top of the loop, but may be specified | |
2500 | explicitly elsewhere. If not currently inside a loop, | |
2501 | return 0 and do nothing; caller will print an error message. */ | |
2502 | ||
2503 | int | |
2504 | expand_continue_loop (whichloop) | |
2505 | struct nesting *whichloop; | |
2506 | { | |
2507 | last_expr_type = 0; | |
2508 | if (whichloop == 0) | |
2509 | whichloop = loop_stack; | |
2510 | if (whichloop == 0) | |
2511 | return 0; | |
37366632 RK |
2512 | expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label, |
2513 | NULL_RTX); | |
28d81abb RK |
2514 | return 1; |
2515 | } | |
2516 | ||
2517 | /* Generate a jump to exit the current loop. If not currently inside a loop, | |
2518 | return 0 and do nothing; caller will print an error message. */ | |
2519 | ||
2520 | int | |
2521 | expand_exit_loop (whichloop) | |
2522 | struct nesting *whichloop; | |
2523 | { | |
2524 | last_expr_type = 0; | |
2525 | if (whichloop == 0) | |
2526 | whichloop = loop_stack; | |
2527 | if (whichloop == 0) | |
2528 | return 0; | |
37366632 | 2529 | expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX); |
28d81abb RK |
2530 | return 1; |
2531 | } | |
2532 | ||
2533 | /* Generate a conditional jump to exit the current loop if COND | |
2534 | evaluates to zero. If not currently inside a loop, | |
2535 | return 0 and do nothing; caller will print an error message. */ | |
2536 | ||
2537 | int | |
2538 | expand_exit_loop_if_false (whichloop, cond) | |
2539 | struct nesting *whichloop; | |
2540 | tree cond; | |
2541 | { | |
2542 | last_expr_type = 0; | |
2543 | if (whichloop == 0) | |
2544 | whichloop = loop_stack; | |
2545 | if (whichloop == 0) | |
2546 | return 0; | |
ca695ac9 JB |
2547 | if (output_bytecode) |
2548 | { | |
2549 | bc_expand_expr (cond); | |
c3a2235b RS |
2550 | bc_expand_goto_internal (xjumpifnot, |
2551 | BYTECODE_BC_LABEL (whichloop->exit_label), | |
c53e9440 | 2552 | NULL_RTX); |
ca695ac9 JB |
2553 | } |
2554 | else | |
2555 | do_jump (cond, whichloop->data.loop.end_label, NULL_RTX); | |
2556 | ||
28d81abb RK |
2557 | return 1; |
2558 | } | |
2559 | ||
2560 | /* Return non-zero if we should preserve sub-expressions as separate | |
2561 | pseudos. We never do so if we aren't optimizing. We always do so | |
2562 | if -fexpensive-optimizations. | |
2563 | ||
2564 | Otherwise, we only do so if we are in the "early" part of a loop. I.e., | |
2565 | the loop may still be a small one. */ | |
2566 | ||
2567 | int | |
2568 | preserve_subexpressions_p () | |
2569 | { | |
2570 | rtx insn; | |
2571 | ||
2572 | if (flag_expensive_optimizations) | |
2573 | return 1; | |
2574 | ||
2575 | if (optimize == 0 || loop_stack == 0) | |
2576 | return 0; | |
2577 | ||
2578 | insn = get_last_insn_anywhere (); | |
2579 | ||
2580 | return (insn | |
2581 | && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label) | |
2582 | < n_non_fixed_regs * 3)); | |
2583 | ||
2584 | } | |
2585 | ||
2586 | /* Generate a jump to exit the current loop, conditional, binding contour | |
2587 | or case statement. Not all such constructs are visible to this function, | |
2588 | only those started with EXIT_FLAG nonzero. Individual languages use | |
2589 | the EXIT_FLAG parameter to control which kinds of constructs you can | |
2590 | exit this way. | |
2591 | ||
2592 | If not currently inside anything that can be exited, | |
2593 | return 0 and do nothing; caller will print an error message. */ | |
2594 | ||
2595 | int | |
2596 | expand_exit_something () | |
2597 | { | |
2598 | struct nesting *n; | |
2599 | last_expr_type = 0; | |
2600 | for (n = nesting_stack; n; n = n->all) | |
2601 | if (n->exit_label != 0) | |
2602 | { | |
37366632 | 2603 | expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX); |
28d81abb RK |
2604 | return 1; |
2605 | } | |
2606 | ||
2607 | return 0; | |
2608 | } | |
2609 | \f | |
2610 | /* Generate RTL to return from the current function, with no value. | |
2611 | (That is, we do not do anything about returning any value.) */ | |
2612 | ||
2613 | void | |
2614 | expand_null_return () | |
2615 | { | |
2616 | struct nesting *block = block_stack; | |
2617 | rtx last_insn = 0; | |
2618 | ||
ca695ac9 JB |
2619 | if (output_bytecode) |
2620 | { | |
2621 | bc_emit_instruction (ret); | |
2622 | return; | |
2623 | } | |
2624 | ||
28d81abb RK |
2625 | /* Does any pending block have cleanups? */ |
2626 | ||
2627 | while (block && block->data.block.cleanups == 0) | |
2628 | block = block->next; | |
2629 | ||
2630 | /* If yes, use a goto to return, since that runs cleanups. */ | |
2631 | ||
2632 | expand_null_return_1 (last_insn, block != 0); | |
2633 | } | |
2634 | ||
2635 | /* Generate RTL to return from the current function, with value VAL. */ | |
2636 | ||
2637 | void | |
2638 | expand_value_return (val) | |
2639 | rtx val; | |
2640 | { | |
2641 | struct nesting *block = block_stack; | |
2642 | rtx last_insn = get_last_insn (); | |
2643 | rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl)); | |
2644 | ||
2645 | /* Copy the value to the return location | |
2646 | unless it's already there. */ | |
2647 | ||
2648 | if (return_reg != val) | |
77636079 RS |
2649 | { |
2650 | #ifdef PROMOTE_FUNCTION_RETURN | |
2651 | enum machine_mode mode = DECL_MODE (DECL_RESULT (current_function_decl)); | |
2652 | tree type = TREE_TYPE (DECL_RESULT (current_function_decl)); | |
2653 | int unsignedp = TREE_UNSIGNED (type); | |
2654 | ||
2655 | if (TREE_CODE (type) == INTEGER_TYPE || TREE_CODE (type) == ENUMERAL_TYPE | |
2656 | || TREE_CODE (type) == BOOLEAN_TYPE || TREE_CODE (type) == CHAR_TYPE | |
2657 | || TREE_CODE (type) == REAL_TYPE || TREE_CODE (type) == POINTER_TYPE | |
2658 | || TREE_CODE (type) == OFFSET_TYPE) | |
2659 | { | |
2660 | PROMOTE_MODE (mode, unsignedp, type); | |
2661 | } | |
2662 | ||
2663 | if (GET_MODE (val) != VOIDmode && GET_MODE (val) != mode) | |
3af6dfd8 | 2664 | convert_move (return_reg, val, unsignedp); |
77636079 RS |
2665 | else |
2666 | #endif | |
2667 | emit_move_insn (return_reg, val); | |
2668 | } | |
28d81abb RK |
2669 | if (GET_CODE (return_reg) == REG |
2670 | && REGNO (return_reg) < FIRST_PSEUDO_REGISTER) | |
2671 | emit_insn (gen_rtx (USE, VOIDmode, return_reg)); | |
2672 | ||
2673 | /* Does any pending block have cleanups? */ | |
2674 | ||
2675 | while (block && block->data.block.cleanups == 0) | |
2676 | block = block->next; | |
2677 | ||
2678 | /* If yes, use a goto to return, since that runs cleanups. | |
2679 | Use LAST_INSN to put cleanups *before* the move insn emitted above. */ | |
2680 | ||
2681 | expand_null_return_1 (last_insn, block != 0); | |
2682 | } | |
2683 | ||
2684 | /* Output a return with no value. If LAST_INSN is nonzero, | |
2685 | pretend that the return takes place after LAST_INSN. | |
2686 | If USE_GOTO is nonzero then don't use a return instruction; | |
2687 | go to the return label instead. This causes any cleanups | |
2688 | of pending blocks to be executed normally. */ | |
2689 | ||
2690 | static void | |
2691 | expand_null_return_1 (last_insn, use_goto) | |
2692 | rtx last_insn; | |
2693 | int use_goto; | |
2694 | { | |
2695 | rtx end_label = cleanup_label ? cleanup_label : return_label; | |
2696 | ||
2697 | clear_pending_stack_adjust (); | |
2698 | do_pending_stack_adjust (); | |
2699 | last_expr_type = 0; | |
2700 | ||
2701 | /* PCC-struct return always uses an epilogue. */ | |
2702 | if (current_function_returns_pcc_struct || use_goto) | |
2703 | { | |
2704 | if (end_label == 0) | |
2705 | end_label = return_label = gen_label_rtx (); | |
37366632 | 2706 | expand_goto_internal (NULL_TREE, end_label, last_insn); |
28d81abb RK |
2707 | return; |
2708 | } | |
2709 | ||
2710 | /* Otherwise output a simple return-insn if one is available, | |
2711 | unless it won't do the job. */ | |
2712 | #ifdef HAVE_return | |
2713 | if (HAVE_return && use_goto == 0 && cleanup_label == 0) | |
2714 | { | |
2715 | emit_jump_insn (gen_return ()); | |
2716 | emit_barrier (); | |
2717 | return; | |
2718 | } | |
2719 | #endif | |
2720 | ||
2721 | /* Otherwise jump to the epilogue. */ | |
37366632 | 2722 | expand_goto_internal (NULL_TREE, end_label, last_insn); |
28d81abb RK |
2723 | } |
2724 | \f | |
2725 | /* Generate RTL to evaluate the expression RETVAL and return it | |
2726 | from the current function. */ | |
2727 | ||
2728 | void | |
2729 | expand_return (retval) | |
2730 | tree retval; | |
2731 | { | |
2732 | /* If there are any cleanups to be performed, then they will | |
2733 | be inserted following LAST_INSN. It is desirable | |
2734 | that the last_insn, for such purposes, should be the | |
2735 | last insn before computing the return value. Otherwise, cleanups | |
2736 | which call functions can clobber the return value. */ | |
2737 | /* ??? rms: I think that is erroneous, because in C++ it would | |
2738 | run destructors on variables that might be used in the subsequent | |
2739 | computation of the return value. */ | |
2740 | rtx last_insn = 0; | |
2741 | register rtx val = 0; | |
2742 | register rtx op0; | |
2743 | tree retval_rhs; | |
2744 | int cleanups; | |
2745 | struct nesting *block; | |
2746 | ||
ca695ac9 JB |
2747 | /* Bytecode returns are quite simple, just leave the result on the |
2748 | arithmetic stack. */ | |
2749 | if (output_bytecode) | |
2750 | { | |
2751 | bc_expand_expr (retval); | |
2752 | bc_emit_instruction (ret); | |
2753 | return; | |
2754 | } | |
2755 | ||
28d81abb RK |
2756 | /* If function wants no value, give it none. */ |
2757 | if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE) | |
2758 | { | |
37366632 | 2759 | expand_expr (retval, NULL_RTX, VOIDmode, 0); |
7e70e7c5 | 2760 | emit_queue (); |
28d81abb RK |
2761 | expand_null_return (); |
2762 | return; | |
2763 | } | |
2764 | ||
2765 | /* Are any cleanups needed? E.g. C++ destructors to be run? */ | |
2766 | cleanups = any_pending_cleanups (1); | |
2767 | ||
2768 | if (TREE_CODE (retval) == RESULT_DECL) | |
2769 | retval_rhs = retval; | |
2770 | else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR) | |
2771 | && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL) | |
2772 | retval_rhs = TREE_OPERAND (retval, 1); | |
2773 | else if (TREE_TYPE (retval) == void_type_node) | |
2774 | /* Recognize tail-recursive call to void function. */ | |
2775 | retval_rhs = retval; | |
2776 | else | |
2777 | retval_rhs = NULL_TREE; | |
2778 | ||
2779 | /* Only use `last_insn' if there are cleanups which must be run. */ | |
2780 | if (cleanups || cleanup_label != 0) | |
2781 | last_insn = get_last_insn (); | |
2782 | ||
2783 | /* Distribute return down conditional expr if either of the sides | |
2784 | may involve tail recursion (see test below). This enhances the number | |
2785 | of tail recursions we see. Don't do this always since it can produce | |
2786 | sub-optimal code in some cases and we distribute assignments into | |
2787 | conditional expressions when it would help. */ | |
2788 | ||
2789 | if (optimize && retval_rhs != 0 | |
2790 | && frame_offset == 0 | |
2791 | && TREE_CODE (retval_rhs) == COND_EXPR | |
2792 | && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR | |
2793 | || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR)) | |
2794 | { | |
2795 | rtx label = gen_label_rtx (); | |
a0a34f94 RK |
2796 | tree expr; |
2797 | ||
37366632 | 2798 | do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX); |
a0a34f94 RK |
2799 | expr = build (MODIFY_EXPR, TREE_TYPE (current_function_decl), |
2800 | DECL_RESULT (current_function_decl), | |
2801 | TREE_OPERAND (retval_rhs, 1)); | |
2802 | TREE_SIDE_EFFECTS (expr) = 1; | |
2803 | expand_return (expr); | |
28d81abb | 2804 | emit_label (label); |
a0a34f94 RK |
2805 | |
2806 | expr = build (MODIFY_EXPR, TREE_TYPE (current_function_decl), | |
2807 | DECL_RESULT (current_function_decl), | |
2808 | TREE_OPERAND (retval_rhs, 2)); | |
2809 | TREE_SIDE_EFFECTS (expr) = 1; | |
2810 | expand_return (expr); | |
28d81abb RK |
2811 | return; |
2812 | } | |
2813 | ||
2814 | /* For tail-recursive call to current function, | |
2815 | just jump back to the beginning. | |
2816 | It's unsafe if any auto variable in this function | |
2817 | has its address taken; for simplicity, | |
2818 | require stack frame to be empty. */ | |
2819 | if (optimize && retval_rhs != 0 | |
2820 | && frame_offset == 0 | |
2821 | && TREE_CODE (retval_rhs) == CALL_EXPR | |
2822 | && TREE_CODE (TREE_OPERAND (retval_rhs, 0)) == ADDR_EXPR | |
2823 | && TREE_OPERAND (TREE_OPERAND (retval_rhs, 0), 0) == current_function_decl | |
2824 | /* Finish checking validity, and if valid emit code | |
2825 | to set the argument variables for the new call. */ | |
2826 | && tail_recursion_args (TREE_OPERAND (retval_rhs, 1), | |
2827 | DECL_ARGUMENTS (current_function_decl))) | |
2828 | { | |
2829 | if (tail_recursion_label == 0) | |
2830 | { | |
2831 | tail_recursion_label = gen_label_rtx (); | |
2832 | emit_label_after (tail_recursion_label, | |
2833 | tail_recursion_reentry); | |
2834 | } | |
a3229491 | 2835 | emit_queue (); |
37366632 | 2836 | expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn); |
28d81abb RK |
2837 | emit_barrier (); |
2838 | return; | |
2839 | } | |
2840 | #ifdef HAVE_return | |
2841 | /* This optimization is safe if there are local cleanups | |
2842 | because expand_null_return takes care of them. | |
2843 | ??? I think it should also be safe when there is a cleanup label, | |
2844 | because expand_null_return takes care of them, too. | |
2845 | Any reason why not? */ | |
2846 | if (HAVE_return && cleanup_label == 0 | |
5eb94e4e RK |
2847 | && ! current_function_returns_pcc_struct |
2848 | && BRANCH_COST <= 1) | |
28d81abb RK |
2849 | { |
2850 | /* If this is return x == y; then generate | |
2851 | if (x == y) return 1; else return 0; | |
5eb94e4e RK |
2852 | if we can do it with explicit return insns and |
2853 | branches are cheap. */ | |
28d81abb RK |
2854 | if (retval_rhs) |
2855 | switch (TREE_CODE (retval_rhs)) | |
2856 | { | |
2857 | case EQ_EXPR: | |
2858 | case NE_EXPR: | |
2859 | case GT_EXPR: | |
2860 | case GE_EXPR: | |
2861 | case LT_EXPR: | |
2862 | case LE_EXPR: | |
2863 | case TRUTH_ANDIF_EXPR: | |
2864 | case TRUTH_ORIF_EXPR: | |
2865 | case TRUTH_AND_EXPR: | |
2866 | case TRUTH_OR_EXPR: | |
2867 | case TRUTH_NOT_EXPR: | |
94ed3915 | 2868 | case TRUTH_XOR_EXPR: |
28d81abb RK |
2869 | op0 = gen_label_rtx (); |
2870 | jumpifnot (retval_rhs, op0); | |
2871 | expand_value_return (const1_rtx); | |
2872 | emit_label (op0); | |
2873 | expand_value_return (const0_rtx); | |
2874 | return; | |
2875 | } | |
2876 | } | |
2877 | #endif /* HAVE_return */ | |
2878 | ||
2879 | if (cleanups | |
2880 | && retval_rhs != 0 | |
2881 | && TREE_TYPE (retval_rhs) != void_type_node | |
2882 | && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG) | |
2883 | { | |
2884 | /* Calculate the return value into a pseudo reg. */ | |
37366632 | 2885 | val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0); |
28d81abb RK |
2886 | emit_queue (); |
2887 | /* All temporaries have now been used. */ | |
2888 | free_temp_slots (); | |
2889 | /* Return the calculated value, doing cleanups first. */ | |
2890 | expand_value_return (val); | |
2891 | } | |
2892 | else | |
2893 | { | |
2894 | /* No cleanups or no hard reg used; | |
2895 | calculate value into hard return reg. */ | |
cba389cd | 2896 | expand_expr (retval, const0_rtx, VOIDmode, 0); |
28d81abb RK |
2897 | emit_queue (); |
2898 | free_temp_slots (); | |
2899 | expand_value_return (DECL_RTL (DECL_RESULT (current_function_decl))); | |
2900 | } | |
2901 | } | |
2902 | ||
2903 | /* Return 1 if the end of the generated RTX is not a barrier. | |
2904 | This means code already compiled can drop through. */ | |
2905 | ||
2906 | int | |
2907 | drop_through_at_end_p () | |
2908 | { | |
2909 | rtx insn = get_last_insn (); | |
2910 | while (insn && GET_CODE (insn) == NOTE) | |
2911 | insn = PREV_INSN (insn); | |
2912 | return insn && GET_CODE (insn) != BARRIER; | |
2913 | } | |
2914 | \f | |
2915 | /* Emit code to alter this function's formal parms for a tail-recursive call. | |
2916 | ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs). | |
2917 | FORMALS is the chain of decls of formals. | |
2918 | Return 1 if this can be done; | |
2919 | otherwise return 0 and do not emit any code. */ | |
2920 | ||
2921 | static int | |
2922 | tail_recursion_args (actuals, formals) | |
2923 | tree actuals, formals; | |
2924 | { | |
2925 | register tree a = actuals, f = formals; | |
2926 | register int i; | |
2927 | register rtx *argvec; | |
2928 | ||
2929 | /* Check that number and types of actuals are compatible | |
2930 | with the formals. This is not always true in valid C code. | |
2931 | Also check that no formal needs to be addressable | |
2932 | and that all formals are scalars. */ | |
2933 | ||
2934 | /* Also count the args. */ | |
2935 | ||
2936 | for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++) | |
2937 | { | |
2938 | if (TREE_TYPE (TREE_VALUE (a)) != TREE_TYPE (f)) | |
2939 | return 0; | |
2940 | if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode) | |
2941 | return 0; | |
2942 | } | |
2943 | if (a != 0 || f != 0) | |
2944 | return 0; | |
2945 | ||
2946 | /* Compute all the actuals. */ | |
2947 | ||
2948 | argvec = (rtx *) alloca (i * sizeof (rtx)); | |
2949 | ||
2950 | for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++) | |
37366632 | 2951 | argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0); |
28d81abb RK |
2952 | |
2953 | /* Find which actual values refer to current values of previous formals. | |
2954 | Copy each of them now, before any formal is changed. */ | |
2955 | ||
2956 | for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++) | |
2957 | { | |
2958 | int copy = 0; | |
2959 | register int j; | |
2960 | for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++) | |
2961 | if (reg_mentioned_p (DECL_RTL (f), argvec[i])) | |
2962 | { copy = 1; break; } | |
2963 | if (copy) | |
2964 | argvec[i] = copy_to_reg (argvec[i]); | |
2965 | } | |
2966 | ||
2967 | /* Store the values of the actuals into the formals. */ | |
2968 | ||
2969 | for (f = formals, a = actuals, i = 0; f; | |
2970 | f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++) | |
2971 | { | |
98f3b471 | 2972 | if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i])) |
28d81abb RK |
2973 | emit_move_insn (DECL_RTL (f), argvec[i]); |
2974 | else | |
2975 | convert_move (DECL_RTL (f), argvec[i], | |
2976 | TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a)))); | |
2977 | } | |
2978 | ||
2979 | free_temp_slots (); | |
2980 | return 1; | |
2981 | } | |
2982 | \f | |
2983 | /* Generate the RTL code for entering a binding contour. | |
2984 | The variables are declared one by one, by calls to `expand_decl'. | |
2985 | ||
2986 | EXIT_FLAG is nonzero if this construct should be visible to | |
2987 | `exit_something'. */ | |
2988 | ||
2989 | void | |
2990 | expand_start_bindings (exit_flag) | |
2991 | int exit_flag; | |
2992 | { | |
2993 | struct nesting *thisblock = ALLOC_NESTING (); | |
ca695ac9 | 2994 | rtx note; |
28d81abb | 2995 | |
ca695ac9 JB |
2996 | if (!output_bytecode) |
2997 | note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG); | |
28d81abb RK |
2998 | |
2999 | /* Make an entry on block_stack for the block we are entering. */ | |
3000 | ||
3001 | thisblock->next = block_stack; | |
3002 | thisblock->all = nesting_stack; | |
3003 | thisblock->depth = ++nesting_depth; | |
3004 | thisblock->data.block.stack_level = 0; | |
3005 | thisblock->data.block.cleanups = 0; | |
3006 | thisblock->data.block.function_call_count = 0; | |
3007 | #if 0 | |
3008 | if (block_stack) | |
3009 | { | |
3010 | if (block_stack->data.block.cleanups == NULL_TREE | |
3011 | && (block_stack->data.block.outer_cleanups == NULL_TREE | |
3012 | || block_stack->data.block.outer_cleanups == empty_cleanup_list)) | |
3013 | thisblock->data.block.outer_cleanups = empty_cleanup_list; | |
3014 | else | |
3015 | thisblock->data.block.outer_cleanups | |
3016 | = tree_cons (NULL_TREE, block_stack->data.block.cleanups, | |
3017 | block_stack->data.block.outer_cleanups); | |
3018 | } | |
3019 | else | |
3020 | thisblock->data.block.outer_cleanups = 0; | |
3021 | #endif | |
3022 | #if 1 | |
3023 | if (block_stack | |
3024 | && !(block_stack->data.block.cleanups == NULL_TREE | |
3025 | && block_stack->data.block.outer_cleanups == NULL_TREE)) | |
3026 | thisblock->data.block.outer_cleanups | |
3027 | = tree_cons (NULL_TREE, block_stack->data.block.cleanups, | |
3028 | block_stack->data.block.outer_cleanups); | |
3029 | else | |
3030 | thisblock->data.block.outer_cleanups = 0; | |
3031 | #endif | |
3032 | thisblock->data.block.label_chain = 0; | |
3033 | thisblock->data.block.innermost_stack_block = stack_block_stack; | |
3034 | thisblock->data.block.first_insn = note; | |
3035 | thisblock->data.block.block_start_count = ++block_start_count; | |
3036 | thisblock->exit_label = exit_flag ? gen_label_rtx () : 0; | |
3037 | block_stack = thisblock; | |
3038 | nesting_stack = thisblock; | |
3039 | ||
ca695ac9 JB |
3040 | if (!output_bytecode) |
3041 | { | |
3042 | /* Make a new level for allocating stack slots. */ | |
3043 | push_temp_slots (); | |
3044 | } | |
28d81abb RK |
3045 | } |
3046 | ||
7629c936 RS |
3047 | /* Given a pointer to a BLOCK node, save a pointer to the most recently |
3048 | generated NOTE_INSN_BLOCK_END in the BLOCK_END_NOTE field of the given | |
3049 | BLOCK node. */ | |
3050 | ||
3051 | void | |
3052 | remember_end_note (block) | |
3053 | register tree block; | |
3054 | { | |
3055 | BLOCK_END_NOTE (block) = last_block_end_note; | |
3056 | last_block_end_note = NULL_RTX; | |
3057 | } | |
3058 | ||
28d81abb RK |
3059 | /* Generate RTL code to terminate a binding contour. |
3060 | VARS is the chain of VAR_DECL nodes | |
3061 | for the variables bound in this contour. | |
3062 | MARK_ENDS is nonzero if we should put a note at the beginning | |
3063 | and end of this binding contour. | |
3064 | ||
3065 | DONT_JUMP_IN is nonzero if it is not valid to jump into this contour. | |
3066 | (That is true automatically if the contour has a saved stack level.) */ | |
3067 | ||
3068 | void | |
3069 | expand_end_bindings (vars, mark_ends, dont_jump_in) | |
3070 | tree vars; | |
3071 | int mark_ends; | |
3072 | int dont_jump_in; | |
3073 | { | |
3074 | register struct nesting *thisblock = block_stack; | |
3075 | register tree decl; | |
3076 | ||
ca695ac9 JB |
3077 | if (output_bytecode) |
3078 | { | |
3079 | bc_expand_end_bindings (vars, mark_ends, dont_jump_in); | |
3080 | return; | |
3081 | } | |
3082 | ||
28d81abb RK |
3083 | if (warn_unused) |
3084 | for (decl = vars; decl; decl = TREE_CHAIN (decl)) | |
7e70e7c5 RS |
3085 | if (! TREE_USED (decl) && TREE_CODE (decl) == VAR_DECL |
3086 | && ! DECL_IN_SYSTEM_HEADER (decl)) | |
28d81abb RK |
3087 | warning_with_decl (decl, "unused variable `%s'"); |
3088 | ||
28d81abb RK |
3089 | if (thisblock->exit_label) |
3090 | { | |
3091 | do_pending_stack_adjust (); | |
3092 | emit_label (thisblock->exit_label); | |
3093 | } | |
3094 | ||
3095 | /* If necessary, make a handler for nonlocal gotos taking | |
3096 | place in the function calls in this block. */ | |
3097 | if (function_call_count != thisblock->data.block.function_call_count | |
3098 | && nonlocal_labels | |
3099 | /* Make handler for outermost block | |
3100 | if there were any nonlocal gotos to this function. */ | |
3101 | && (thisblock->next == 0 ? current_function_has_nonlocal_label | |
3102 | /* Make handler for inner block if it has something | |
3103 | special to do when you jump out of it. */ | |
3104 | : (thisblock->data.block.cleanups != 0 | |
3105 | || thisblock->data.block.stack_level != 0))) | |
3106 | { | |
3107 | tree link; | |
3108 | rtx afterward = gen_label_rtx (); | |
3109 | rtx handler_label = gen_label_rtx (); | |
3110 | rtx save_receiver = gen_reg_rtx (Pmode); | |
ba83886f | 3111 | rtx insns; |
28d81abb RK |
3112 | |
3113 | /* Don't let jump_optimize delete the handler. */ | |
3114 | LABEL_PRESERVE_P (handler_label) = 1; | |
3115 | ||
3116 | /* Record the handler address in the stack slot for that purpose, | |
3117 | during this block, saving and restoring the outer value. */ | |
3118 | if (thisblock->next != 0) | |
3119 | { | |
3120 | emit_move_insn (nonlocal_goto_handler_slot, save_receiver); | |
ba83886f RS |
3121 | |
3122 | start_sequence (); | |
3123 | emit_move_insn (save_receiver, nonlocal_goto_handler_slot); | |
3124 | insns = get_insns (); | |
3125 | end_sequence (); | |
3126 | emit_insns_before (insns, thisblock->data.block.first_insn); | |
28d81abb | 3127 | } |
ba83886f RS |
3128 | |
3129 | start_sequence (); | |
3130 | emit_move_insn (nonlocal_goto_handler_slot, | |
3131 | gen_rtx (LABEL_REF, Pmode, handler_label)); | |
3132 | insns = get_insns (); | |
3133 | end_sequence (); | |
3134 | emit_insns_before (insns, thisblock->data.block.first_insn); | |
28d81abb RK |
3135 | |
3136 | /* Jump around the handler; it runs only when specially invoked. */ | |
3137 | emit_jump (afterward); | |
3138 | emit_label (handler_label); | |
3139 | ||
3140 | #ifdef HAVE_nonlocal_goto | |
3141 | if (! HAVE_nonlocal_goto) | |
3142 | #endif | |
3143 | /* First adjust our frame pointer to its actual value. It was | |
3144 | previously set to the start of the virtual area corresponding to | |
3145 | the stacked variables when we branched here and now needs to be | |
3146 | adjusted to the actual hardware fp value. | |
3147 | ||
3148 | Assignments are to virtual registers are converted by | |
3149 | instantiate_virtual_regs into the corresponding assignment | |
3150 | to the underlying register (fp in this case) that makes | |
3151 | the original assignment true. | |
3152 | So the following insn will actually be | |
3153 | decrementing fp by STARTING_FRAME_OFFSET. */ | |
3154 | emit_move_insn (virtual_stack_vars_rtx, frame_pointer_rtx); | |
3155 | ||
a35ad168 | 3156 | #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM |
28d81abb RK |
3157 | if (fixed_regs[ARG_POINTER_REGNUM]) |
3158 | { | |
42495ca0 RK |
3159 | #ifdef ELIMINABLE_REGS |
3160 | /* If the argument pointer can be eliminated in favor of the | |
3161 | frame pointer, we don't need to restore it. We assume here | |
3162 | that if such an elimination is present, it can always be used. | |
3163 | This is the case on all known machines; if we don't make this | |
3164 | assumption, we do unnecessary saving on many machines. */ | |
3165 | static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS; | |
3166 | int i; | |
3167 | ||
3168 | for (i = 0; i < sizeof elim_regs / sizeof elim_regs[0]; i++) | |
3169 | if (elim_regs[i].from == ARG_POINTER_REGNUM | |
a35ad168 | 3170 | && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM) |
42495ca0 RK |
3171 | break; |
3172 | ||
3173 | if (i == sizeof elim_regs / sizeof elim_regs [0]) | |
3174 | #endif | |
3175 | { | |
3176 | /* Now restore our arg pointer from the address at which it | |
3177 | was saved in our stack frame. | |
3178 | If there hasn't be space allocated for it yet, make | |
3179 | some now. */ | |
3180 | if (arg_pointer_save_area == 0) | |
3181 | arg_pointer_save_area | |
3182 | = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0); | |
3183 | emit_move_insn (virtual_incoming_args_rtx, | |
3184 | /* We need a pseudo here, or else | |
3185 | instantiate_virtual_regs_1 complains. */ | |
3186 | copy_to_reg (arg_pointer_save_area)); | |
3187 | } | |
28d81abb RK |
3188 | } |
3189 | #endif | |
3190 | ||
3191 | /* The handler expects the desired label address in the static chain | |
3192 | register. It tests the address and does an appropriate jump | |
3193 | to whatever label is desired. */ | |
3194 | for (link = nonlocal_labels; link; link = TREE_CHAIN (link)) | |
3195 | /* Skip any labels we shouldn't be able to jump to from here. */ | |
3196 | if (! DECL_TOO_LATE (TREE_VALUE (link))) | |
3197 | { | |
3198 | rtx not_this = gen_label_rtx (); | |
3199 | rtx this = gen_label_rtx (); | |
3200 | do_jump_if_equal (static_chain_rtx, | |
3201 | gen_rtx (LABEL_REF, Pmode, DECL_RTL (TREE_VALUE (link))), | |
3202 | this, 0); | |
3203 | emit_jump (not_this); | |
3204 | emit_label (this); | |
3205 | expand_goto (TREE_VALUE (link)); | |
3206 | emit_label (not_this); | |
3207 | } | |
3208 | /* If label is not recognized, abort. */ | |
3209 | emit_library_call (gen_rtx (SYMBOL_REF, Pmode, "abort"), 0, | |
3210 | VOIDmode, 0); | |
3211 | emit_label (afterward); | |
3212 | } | |
3213 | ||
3214 | /* Don't allow jumping into a block that has cleanups or a stack level. */ | |
3215 | if (dont_jump_in | |
3216 | || thisblock->data.block.stack_level != 0 | |
3217 | || thisblock->data.block.cleanups != 0) | |
3218 | { | |
3219 | struct label_chain *chain; | |
3220 | ||
3221 | /* Any labels in this block are no longer valid to go to. | |
3222 | Mark them to cause an error message. */ | |
3223 | for (chain = thisblock->data.block.label_chain; chain; chain = chain->next) | |
3224 | { | |
3225 | DECL_TOO_LATE (chain->label) = 1; | |
3226 | /* If any goto without a fixup came to this label, | |
3227 | that must be an error, because gotos without fixups | |
3228 | come from outside all saved stack-levels and all cleanups. */ | |
3229 | if (TREE_ADDRESSABLE (chain->label)) | |
3230 | error_with_decl (chain->label, | |
3231 | "label `%s' used before containing binding contour"); | |
3232 | } | |
3233 | } | |
3234 | ||
3235 | /* Restore stack level in effect before the block | |
3236 | (only if variable-size objects allocated). */ | |
3237 | /* Perform any cleanups associated with the block. */ | |
3238 | ||
3239 | if (thisblock->data.block.stack_level != 0 | |
3240 | || thisblock->data.block.cleanups != 0) | |
3241 | { | |
3242 | /* Don't let cleanups affect ({...}) constructs. */ | |
3243 | int old_expr_stmts_for_value = expr_stmts_for_value; | |
3244 | rtx old_last_expr_value = last_expr_value; | |
3245 | tree old_last_expr_type = last_expr_type; | |
3246 | expr_stmts_for_value = 0; | |
3247 | ||
3248 | /* Do the cleanups. */ | |
37366632 | 3249 | expand_cleanups (thisblock->data.block.cleanups, NULL_TREE); |
28d81abb RK |
3250 | do_pending_stack_adjust (); |
3251 | ||
3252 | expr_stmts_for_value = old_expr_stmts_for_value; | |
3253 | last_expr_value = old_last_expr_value; | |
3254 | last_expr_type = old_last_expr_type; | |
3255 | ||
3256 | /* Restore the stack level. */ | |
3257 | ||
3258 | if (thisblock->data.block.stack_level != 0) | |
3259 | { | |
59257ff7 | 3260 | emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION, |
37366632 | 3261 | thisblock->data.block.stack_level, NULL_RTX); |
59257ff7 | 3262 | if (nonlocal_goto_handler_slot != 0) |
37366632 RK |
3263 | emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level, |
3264 | NULL_RTX); | |
28d81abb RK |
3265 | } |
3266 | ||
3267 | /* Any gotos out of this block must also do these things. | |
59257ff7 RK |
3268 | Also report any gotos with fixups that came to labels in this |
3269 | level. */ | |
28d81abb RK |
3270 | fixup_gotos (thisblock, |
3271 | thisblock->data.block.stack_level, | |
3272 | thisblock->data.block.cleanups, | |
3273 | thisblock->data.block.first_insn, | |
3274 | dont_jump_in); | |
3275 | } | |
3276 | ||
c7d2d61d RS |
3277 | /* Mark the beginning and end of the scope if requested. |
3278 | We do this now, after running cleanups on the variables | |
3279 | just going out of scope, so they are in scope for their cleanups. */ | |
3280 | ||
3281 | if (mark_ends) | |
7629c936 | 3282 | last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END); |
c7d2d61d RS |
3283 | else |
3284 | /* Get rid of the beginning-mark if we don't make an end-mark. */ | |
3285 | NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED; | |
3286 | ||
28d81abb RK |
3287 | /* If doing stupid register allocation, make sure lives of all |
3288 | register variables declared here extend thru end of scope. */ | |
3289 | ||
3290 | if (obey_regdecls) | |
3291 | for (decl = vars; decl; decl = TREE_CHAIN (decl)) | |
3292 | { | |
3293 | rtx rtl = DECL_RTL (decl); | |
3294 | if (TREE_CODE (decl) == VAR_DECL && rtl != 0) | |
3295 | use_variable (rtl); | |
3296 | } | |
3297 | ||
3298 | /* Restore block_stack level for containing block. */ | |
3299 | ||
3300 | stack_block_stack = thisblock->data.block.innermost_stack_block; | |
3301 | POPSTACK (block_stack); | |
3302 | ||
3303 | /* Pop the stack slot nesting and free any slots at this level. */ | |
3304 | pop_temp_slots (); | |
3305 | } | |
ca695ac9 JB |
3306 | |
3307 | ||
3308 | /* End a binding contour. | |
3309 | VARS is the chain of VAR_DECL nodes for the variables bound | |
3310 | in this contour. MARK_ENDS is nonzer if we should put a note | |
3311 | at the beginning and end of this binding contour. | |
3312 | DONT_JUMP_IN is nonzero if it is not valid to jump into this | |
3313 | contour. */ | |
3314 | ||
3315 | void | |
3316 | bc_expand_end_bindings (vars, mark_ends, dont_jump_in) | |
3317 | tree vars; | |
3318 | int mark_ends; | |
3319 | int dont_jump_in; | |
3320 | { | |
3321 | struct nesting *thisbind = nesting_stack; | |
3322 | tree decl; | |
3323 | ||
3324 | if (warn_unused) | |
3325 | for (decl = vars; decl; decl = TREE_CHAIN (decl)) | |
3326 | if (! TREE_USED (TREE_VALUE (decl)) && TREE_CODE (TREE_VALUE (decl)) == VAR_DECL) | |
3327 | warning_with_decl (decl, "unused variable `%s'"); | |
3328 | ||
c53e9440 | 3329 | bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisbind->exit_label)); |
ca695ac9 JB |
3330 | |
3331 | /* Pop block/bindings off stack */ | |
3332 | POPSTACK (nesting_stack); | |
3333 | POPSTACK (block_stack); | |
3334 | } | |
28d81abb RK |
3335 | \f |
3336 | /* Generate RTL for the automatic variable declaration DECL. | |
3337 | (Other kinds of declarations are simply ignored if seen here.) | |
3338 | CLEANUP is an expression to be executed at exit from this binding contour; | |
3339 | for example, in C++, it might call the destructor for this variable. | |
3340 | ||
3341 | If CLEANUP contains any SAVE_EXPRs, then you must preevaluate them | |
3342 | either before or after calling `expand_decl' but before compiling | |
3343 | any subsequent expressions. This is because CLEANUP may be expanded | |
3344 | more than once, on different branches of execution. | |
3345 | For the same reason, CLEANUP may not contain a CALL_EXPR | |
3346 | except as its topmost node--else `preexpand_calls' would get confused. | |
3347 | ||
3348 | If CLEANUP is nonzero and DECL is zero, we record a cleanup | |
3349 | that is not associated with any particular variable. | |
3350 | ||
3351 | There is no special support here for C++ constructors. | |
3352 | They should be handled by the proper code in DECL_INITIAL. */ | |
3353 | ||
3354 | void | |
3355 | expand_decl (decl) | |
3356 | register tree decl; | |
3357 | { | |
3358 | struct nesting *thisblock = block_stack; | |
ca695ac9 JB |
3359 | tree type; |
3360 | ||
3361 | if (output_bytecode) | |
3362 | { | |
3363 | bc_expand_decl (decl, 0); | |
3364 | return; | |
3365 | } | |
3366 | ||
3367 | type = TREE_TYPE (decl); | |
28d81abb RK |
3368 | |
3369 | /* Only automatic variables need any expansion done. | |
3370 | Static and external variables, and external functions, | |
3371 | will be handled by `assemble_variable' (called from finish_decl). | |
3372 | TYPE_DECL and CONST_DECL require nothing. | |
3373 | PARM_DECLs are handled in `assign_parms'. */ | |
3374 | ||
3375 | if (TREE_CODE (decl) != VAR_DECL) | |
3376 | return; | |
44fe2e80 | 3377 | if (TREE_STATIC (decl) || DECL_EXTERNAL (decl)) |
28d81abb RK |
3378 | return; |
3379 | ||
3380 | /* Create the RTL representation for the variable. */ | |
3381 | ||
3382 | if (type == error_mark_node) | |
3383 | DECL_RTL (decl) = gen_rtx (MEM, BLKmode, const0_rtx); | |
3384 | else if (DECL_SIZE (decl) == 0) | |
3385 | /* Variable with incomplete type. */ | |
3386 | { | |
3387 | if (DECL_INITIAL (decl) == 0) | |
3388 | /* Error message was already done; now avoid a crash. */ | |
3389 | DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1); | |
3390 | else | |
3391 | /* An initializer is going to decide the size of this array. | |
3392 | Until we know the size, represent its address with a reg. */ | |
3393 | DECL_RTL (decl) = gen_rtx (MEM, BLKmode, gen_reg_rtx (Pmode)); | |
3394 | } | |
3395 | else if (DECL_MODE (decl) != BLKmode | |
3396 | /* If -ffloat-store, don't put explicit float vars | |
3397 | into regs. */ | |
3398 | && !(flag_float_store | |
3399 | && TREE_CODE (type) == REAL_TYPE) | |
3400 | && ! TREE_THIS_VOLATILE (decl) | |
3401 | && ! TREE_ADDRESSABLE (decl) | |
44fe2e80 | 3402 | && (DECL_REGISTER (decl) || ! obey_regdecls)) |
28d81abb RK |
3403 | { |
3404 | /* Automatic variable that can go in a register. */ | |
98f3b471 RK |
3405 | enum machine_mode reg_mode = DECL_MODE (decl); |
3406 | int unsignedp = TREE_UNSIGNED (type); | |
3407 | ||
3408 | if (TREE_CODE (type) == INTEGER_TYPE || TREE_CODE (type) == ENUMERAL_TYPE | |
3409 | || TREE_CODE (type) == BOOLEAN_TYPE || TREE_CODE (type) == CHAR_TYPE | |
3410 | || TREE_CODE (type) == REAL_TYPE || TREE_CODE (type) == POINTER_TYPE | |
3411 | || TREE_CODE (type) == OFFSET_TYPE) | |
3412 | { | |
3413 | PROMOTE_MODE (reg_mode, unsignedp, type); | |
3414 | } | |
3415 | ||
5998c7dc RS |
3416 | if (TREE_CODE (type) == COMPLEX_TYPE) |
3417 | { | |
3418 | rtx realpart, imagpart; | |
3419 | enum machine_mode partmode = TYPE_MODE (TREE_TYPE (type)); | |
3420 | ||
3421 | /* For a complex type variable, make a CONCAT of two pseudos | |
3422 | so that the real and imaginary parts | |
3423 | can be allocated separately. */ | |
3424 | realpart = gen_reg_rtx (partmode); | |
3425 | REG_USERVAR_P (realpart) = 1; | |
3426 | imagpart = gen_reg_rtx (partmode); | |
3427 | REG_USERVAR_P (imagpart) = 1; | |
3428 | DECL_RTL (decl) = gen_rtx (CONCAT, reg_mode, realpart, imagpart); | |
3429 | } | |
3430 | else | |
3431 | { | |
3432 | DECL_RTL (decl) = gen_reg_rtx (reg_mode); | |
3433 | if (TREE_CODE (type) == POINTER_TYPE) | |
3434 | mark_reg_pointer (DECL_RTL (decl)); | |
3435 | REG_USERVAR_P (DECL_RTL (decl)) = 1; | |
3436 | } | |
28d81abb RK |
3437 | } |
3438 | else if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST) | |
3439 | { | |
3440 | /* Variable of fixed size that goes on the stack. */ | |
3441 | rtx oldaddr = 0; | |
3442 | rtx addr; | |
3443 | ||
3444 | /* If we previously made RTL for this decl, it must be an array | |
3445 | whose size was determined by the initializer. | |
3446 | The old address was a register; set that register now | |
3447 | to the proper address. */ | |
3448 | if (DECL_RTL (decl) != 0) | |
3449 | { | |
3450 | if (GET_CODE (DECL_RTL (decl)) != MEM | |
3451 | || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG) | |
3452 | abort (); | |
3453 | oldaddr = XEXP (DECL_RTL (decl), 0); | |
3454 | } | |
3455 | ||
3456 | DECL_RTL (decl) | |
3457 | = assign_stack_temp (DECL_MODE (decl), | |
3458 | ((TREE_INT_CST_LOW (DECL_SIZE (decl)) | |
3459 | + BITS_PER_UNIT - 1) | |
3460 | / BITS_PER_UNIT), | |
3461 | 1); | |
3462 | ||
3463 | /* Set alignment we actually gave this decl. */ | |
3464 | DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT | |
3465 | : GET_MODE_BITSIZE (DECL_MODE (decl))); | |
3466 | ||
3467 | if (oldaddr) | |
3468 | { | |
3469 | addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr); | |
3470 | if (addr != oldaddr) | |
3471 | emit_move_insn (oldaddr, addr); | |
3472 | } | |
3473 | ||
3474 | /* If this is a memory ref that contains aggregate components, | |
3475 | mark it as such for cse and loop optimize. */ | |
3476 | MEM_IN_STRUCT_P (DECL_RTL (decl)) | |
3477 | = (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE | |
3478 | || TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE | |
c1b98a95 RK |
3479 | || TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE |
3480 | || TREE_CODE (TREE_TYPE (decl)) == QUAL_UNION_TYPE); | |
28d81abb RK |
3481 | #if 0 |
3482 | /* If this is in memory because of -ffloat-store, | |
3483 | set the volatile bit, to prevent optimizations from | |
3484 | undoing the effects. */ | |
3485 | if (flag_float_store && TREE_CODE (type) == REAL_TYPE) | |
3486 | MEM_VOLATILE_P (DECL_RTL (decl)) = 1; | |
3487 | #endif | |
3488 | } | |
3489 | else | |
3490 | /* Dynamic-size object: must push space on the stack. */ | |
3491 | { | |
3492 | rtx address, size; | |
3493 | ||
3494 | /* Record the stack pointer on entry to block, if have | |
3495 | not already done so. */ | |
3496 | if (thisblock->data.block.stack_level == 0) | |
3497 | { | |
3498 | do_pending_stack_adjust (); | |
59257ff7 RK |
3499 | emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION, |
3500 | &thisblock->data.block.stack_level, | |
3501 | thisblock->data.block.first_insn); | |
28d81abb RK |
3502 | stack_block_stack = thisblock; |
3503 | } | |
3504 | ||
3505 | /* Compute the variable's size, in bytes. */ | |
3506 | size = expand_expr (size_binop (CEIL_DIV_EXPR, | |
3507 | DECL_SIZE (decl), | |
3508 | size_int (BITS_PER_UNIT)), | |
37366632 | 3509 | NULL_RTX, VOIDmode, 0); |
28d81abb RK |
3510 | free_temp_slots (); |
3511 | ||
59257ff7 RK |
3512 | /* This is equivalent to calling alloca. */ |
3513 | current_function_calls_alloca = 1; | |
3514 | ||
28d81abb | 3515 | /* Allocate space on the stack for the variable. */ |
37366632 RK |
3516 | address = allocate_dynamic_stack_space (size, NULL_RTX, |
3517 | DECL_ALIGN (decl)); | |
28d81abb | 3518 | |
59257ff7 | 3519 | if (nonlocal_goto_handler_slot != 0) |
37366632 | 3520 | emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level, NULL_RTX); |
28d81abb RK |
3521 | |
3522 | /* Reference the variable indirect through that rtx. */ | |
3523 | DECL_RTL (decl) = gen_rtx (MEM, DECL_MODE (decl), address); | |
3524 | ||
2207e295 RS |
3525 | /* If this is a memory ref that contains aggregate components, |
3526 | mark it as such for cse and loop optimize. */ | |
3527 | MEM_IN_STRUCT_P (DECL_RTL (decl)) | |
3528 | = (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE | |
3529 | || TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE | |
c1b98a95 RK |
3530 | || TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE |
3531 | || TREE_CODE (TREE_TYPE (decl)) == QUAL_UNION_TYPE); | |
2207e295 | 3532 | |
28d81abb RK |
3533 | /* Indicate the alignment we actually gave this variable. */ |
3534 | #ifdef STACK_BOUNDARY | |
3535 | DECL_ALIGN (decl) = STACK_BOUNDARY; | |
3536 | #else | |
3537 | DECL_ALIGN (decl) = BIGGEST_ALIGNMENT; | |
3538 | #endif | |
3539 | } | |
3540 | ||
3541 | if (TREE_THIS_VOLATILE (decl)) | |
3542 | MEM_VOLATILE_P (DECL_RTL (decl)) = 1; | |
b4bf13a8 RS |
3543 | #if 0 /* A variable is not necessarily unchanging |
3544 | just because it is const. RTX_UNCHANGING_P | |
3545 | means no change in the function, | |
3546 | not merely no change in the variable's scope. | |
3547 | It is correct to set RTX_UNCHANGING_P if the variable's scope | |
3548 | is the whole function. There's no convenient way to test that. */ | |
28d81abb RK |
3549 | if (TREE_READONLY (decl)) |
3550 | RTX_UNCHANGING_P (DECL_RTL (decl)) = 1; | |
b4bf13a8 | 3551 | #endif |
28d81abb RK |
3552 | |
3553 | /* If doing stupid register allocation, make sure life of any | |
3554 | register variable starts here, at the start of its scope. */ | |
3555 | ||
3556 | if (obey_regdecls) | |
3557 | use_variable (DECL_RTL (decl)); | |
3558 | } | |
ca695ac9 JB |
3559 | |
3560 | ||
3561 | /* Generate code for the automatic variable declaration DECL. For | |
3562 | most variables this just means we give it a stack offset. The | |
3563 | compiler sometimes emits cleanups without variables and we will | |
3564 | have to deal with those too. */ | |
3565 | ||
3566 | void | |
3567 | bc_expand_decl (decl, cleanup) | |
3568 | tree decl; | |
3569 | tree cleanup; | |
3570 | { | |
3571 | tree type; | |
3572 | ||
3573 | if (!decl) | |
3574 | { | |
3575 | /* A cleanup with no variable. */ | |
3576 | if (!cleanup) | |
3577 | abort (); | |
3578 | ||
3579 | return; | |
3580 | } | |
3581 | ||
3582 | /* Only auto variables need any work. */ | |
3583 | if (TREE_CODE (decl) != VAR_DECL || TREE_STATIC (decl) || DECL_EXTERNAL (decl)) | |
3584 | return; | |
3585 | ||
3586 | type = TREE_TYPE (decl); | |
3587 | ||
3588 | if (type == error_mark_node) | |
3589 | DECL_RTL (decl) = bc_gen_rtx ((char *) 0, 0, (struct bc_label *) 0); | |
3590 | ||
3591 | else if (DECL_SIZE (decl) == 0) | |
3592 | ||
3593 | /* Variable with incomplete type. The stack offset herein will be | |
3594 | fixed later in expand_decl_init (). */ | |
3595 | DECL_RTL (decl) = bc_gen_rtx ((char *) 0, 0, (struct bc_label *) 0); | |
3596 | ||
3597 | else if (TREE_CONSTANT (DECL_SIZE (decl))) | |
3598 | { | |
3599 | DECL_RTL (decl) = bc_allocate_local (TREE_INT_CST_LOW (DECL_SIZE (decl)) / BITS_PER_UNIT, | |
3600 | DECL_ALIGN (decl)); | |
3601 | } | |
3602 | else | |
3603 | DECL_RTL (decl) = bc_allocate_variable_array (DECL_SIZE (decl)); | |
3604 | } | |
28d81abb RK |
3605 | \f |
3606 | /* Emit code to perform the initialization of a declaration DECL. */ | |
3607 | ||
3608 | void | |
3609 | expand_decl_init (decl) | |
3610 | tree decl; | |
3611 | { | |
b4ac57ab RS |
3612 | int was_used = TREE_USED (decl); |
3613 | ||
3564e40e RK |
3614 | /* If this is a CONST_DECL, we don't have to generate any code, but |
3615 | if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL | |
3616 | to be set while in the obstack containing the constant. If we don't | |
3617 | do this, we can lose if we have functions nested three deep and the middle | |
3618 | function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while | |
3619 | the innermost function is the first to expand that STRING_CST. */ | |
3620 | if (TREE_CODE (decl) == CONST_DECL) | |
3621 | { | |
3622 | if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl))) | |
3623 | expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode, | |
3624 | EXPAND_INITIALIZER); | |
3625 | return; | |
3626 | } | |
3627 | ||
28d81abb RK |
3628 | if (TREE_STATIC (decl)) |
3629 | return; | |
3630 | ||
3631 | /* Compute and store the initial value now. */ | |
3632 | ||
3633 | if (DECL_INITIAL (decl) == error_mark_node) | |
3634 | { | |
3635 | enum tree_code code = TREE_CODE (TREE_TYPE (decl)); | |
3636 | if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE | |
3637 | || code == POINTER_TYPE) | |
3638 | expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node), | |
3639 | 0, 0); | |
3640 | emit_queue (); | |
3641 | } | |
3642 | else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST) | |
3643 | { | |
3644 | emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl)); | |
3645 | expand_assignment (decl, DECL_INITIAL (decl), 0, 0); | |
3646 | emit_queue (); | |
3647 | } | |
3648 | ||
b4ac57ab RS |
3649 | /* Don't let the initialization count as "using" the variable. */ |
3650 | TREE_USED (decl) = was_used; | |
3651 | ||
28d81abb RK |
3652 | /* Free any temporaries we made while initializing the decl. */ |
3653 | free_temp_slots (); | |
3654 | } | |
3655 | ||
ca695ac9 JB |
3656 | /* Expand initialization for variable-sized types. Allocate array |
3657 | using newlocalSI and set local variable, which is a pointer to the | |
3658 | storage. */ | |
3659 | ||
3660 | bc_expand_variable_local_init (decl) | |
3661 | tree decl; | |
3662 | { | |
3663 | /* Evaluate size expression and coerce to SI */ | |
3664 | bc_expand_expr (DECL_SIZE (decl)); | |
3665 | ||
3666 | /* Type sizes are always (?) of TREE_CODE INTEGER_CST, so | |
3667 | no coercion is necessary (?) */ | |
3668 | ||
3669 | /* emit_typecode_conversion (preferred_typecode (TYPE_MODE (DECL_SIZE (decl)), | |
3670 | TREE_UNSIGNED (DECL_SIZE (decl))), SIcode); */ | |
3671 | ||
3672 | /* Emit code to allocate array */ | |
3673 | bc_emit_instruction (newlocalSI); | |
3674 | ||
3675 | /* Store array pointer in local variable. This is the only instance | |
3676 | where we actually want the address of the pointer to the | |
3677 | variable-size block, rather than the pointer itself. We avoid | |
3678 | using expand_address() since that would cause the pointer to be | |
3679 | pushed rather than its address. Hence the hard-coded reference; | |
3680 | notice also that the variable is always local (no global | |
3681 | variable-size type variables). */ | |
3682 | ||
3683 | bc_load_localaddr (DECL_RTL (decl)); | |
3684 | bc_emit_instruction (storeP); | |
3685 | } | |
3686 | ||
3687 | ||
3688 | /* Emit code to initialize a declaration. */ | |
3689 | void | |
3690 | bc_expand_decl_init (decl) | |
3691 | tree decl; | |
3692 | { | |
3693 | int org_stack_depth; | |
3694 | ||
3695 | /* Statical initializers are handled elsewhere */ | |
3696 | ||
3697 | if (TREE_STATIC (decl)) | |
3698 | return; | |
3699 | ||
3700 | /* Memory original stack depth */ | |
3701 | org_stack_depth = stack_depth; | |
3702 | ||
3703 | /* If the type is variable-size, we first create its space (we ASSUME | |
3704 | it CAN'T be static). We do this regardless of whether there's an | |
3705 | initializer assignment or not. */ | |
3706 | ||
3707 | if (TREE_CODE (DECL_SIZE (decl)) != INTEGER_CST) | |
3708 | bc_expand_variable_local_init (decl); | |
3709 | ||
3710 | /* Expand initializer assignment */ | |
3711 | if (DECL_INITIAL (decl) == error_mark_node) | |
3712 | { | |
3713 | enum tree_code code = TREE_CODE (TREE_TYPE (decl)); | |
3714 | ||
3715 | if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE | |
3716 | || code == POINTER_TYPE) | |
3717 | ||
e81d77b5 | 3718 | expand_assignment (TREE_TYPE (decl), decl, 0, 0); |
ca695ac9 JB |
3719 | } |
3720 | else if (DECL_INITIAL (decl)) | |
e81d77b5 | 3721 | expand_assignment (TREE_TYPE (decl), decl, 0, 0); |
ca695ac9 JB |
3722 | |
3723 | /* Restore stack depth */ | |
3724 | if (org_stack_depth > stack_depth) | |
3725 | abort (); | |
3726 | ||
3727 | bc_adjust_stack (stack_depth - org_stack_depth); | |
3728 | } | |
3729 | ||
3730 | ||
28d81abb RK |
3731 | /* CLEANUP is an expression to be executed at exit from this binding contour; |
3732 | for example, in C++, it might call the destructor for this variable. | |
3733 | ||
3734 | If CLEANUP contains any SAVE_EXPRs, then you must preevaluate them | |
3735 | either before or after calling `expand_decl' but before compiling | |
3736 | any subsequent expressions. This is because CLEANUP may be expanded | |
3737 | more than once, on different branches of execution. | |
3738 | For the same reason, CLEANUP may not contain a CALL_EXPR | |
3739 | except as its topmost node--else `preexpand_calls' would get confused. | |
3740 | ||
3741 | If CLEANUP is nonzero and DECL is zero, we record a cleanup | |
3742 | that is not associated with any particular variable. */ | |
3743 | ||
3744 | int | |
3745 | expand_decl_cleanup (decl, cleanup) | |
3746 | tree decl, cleanup; | |
3747 | { | |
3748 | struct nesting *thisblock = block_stack; | |
3749 | ||
3750 | /* Error if we are not in any block. */ | |
3751 | if (thisblock == 0) | |
3752 | return 0; | |
3753 | ||
3754 | /* Record the cleanup if there is one. */ | |
3755 | ||
3756 | if (cleanup != 0) | |
3757 | { | |
3758 | thisblock->data.block.cleanups | |
3759 | = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups); | |
3760 | /* If this block has a cleanup, it belongs in stack_block_stack. */ | |
3761 | stack_block_stack = thisblock; | |
3762 | } | |
3763 | return 1; | |
3764 | } | |
3765 | \f | |
3766 | /* DECL is an anonymous union. CLEANUP is a cleanup for DECL. | |
3767 | DECL_ELTS is the list of elements that belong to DECL's type. | |
3768 | In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */ | |
3769 | ||
3770 | void | |
3771 | expand_anon_union_decl (decl, cleanup, decl_elts) | |
3772 | tree decl, cleanup, decl_elts; | |
3773 | { | |
3774 | struct nesting *thisblock = block_stack; | |
3775 | rtx x; | |
3776 | ||
3777 | expand_decl (decl, cleanup); | |
3778 | x = DECL_RTL (decl); | |
3779 | ||
3780 | while (decl_elts) | |
3781 | { | |
3782 | tree decl_elt = TREE_VALUE (decl_elts); | |
3783 | tree cleanup_elt = TREE_PURPOSE (decl_elts); | |
3784 | enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt)); | |
3785 | ||
3786 | /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we | |
3787 | instead create a new MEM rtx with the proper mode. */ | |
3788 | if (GET_CODE (x) == MEM) | |
3789 | { | |
3790 | if (mode == GET_MODE (x)) | |
3791 | DECL_RTL (decl_elt) = x; | |
3792 | else | |
3793 | { | |
3794 | DECL_RTL (decl_elt) = gen_rtx (MEM, mode, copy_rtx (XEXP (x, 0))); | |
3795 | MEM_IN_STRUCT_P (DECL_RTL (decl_elt)) = MEM_IN_STRUCT_P (x); | |
3796 | RTX_UNCHANGING_P (DECL_RTL (decl_elt)) = RTX_UNCHANGING_P (x); | |
3797 | } | |
3798 | } | |
3799 | else if (GET_CODE (x) == REG) | |
3800 | { | |
3801 | if (mode == GET_MODE (x)) | |
3802 | DECL_RTL (decl_elt) = x; | |
3803 | else | |
3804 | DECL_RTL (decl_elt) = gen_rtx (SUBREG, mode, x, 0); | |
3805 | } | |
3806 | else | |
3807 | abort (); | |
3808 | ||
3809 | /* Record the cleanup if there is one. */ | |
3810 | ||
3811 | if (cleanup != 0) | |
3812 | thisblock->data.block.cleanups | |
3813 | = temp_tree_cons (decl_elt, cleanup_elt, | |
3814 | thisblock->data.block.cleanups); | |
3815 | ||
3816 | decl_elts = TREE_CHAIN (decl_elts); | |
3817 | } | |
3818 | } | |
3819 | \f | |
3820 | /* Expand a list of cleanups LIST. | |
3821 | Elements may be expressions or may be nested lists. | |
3822 | ||
3823 | If DONT_DO is nonnull, then any list-element | |
3824 | whose TREE_PURPOSE matches DONT_DO is omitted. | |
3825 | This is sometimes used to avoid a cleanup associated with | |
3826 | a value that is being returned out of the scope. */ | |
3827 | ||
3828 | static void | |
3829 | expand_cleanups (list, dont_do) | |
3830 | tree list; | |
3831 | tree dont_do; | |
3832 | { | |
3833 | tree tail; | |
3834 | for (tail = list; tail; tail = TREE_CHAIN (tail)) | |
3835 | if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do) | |
3836 | { | |
3837 | if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST) | |
3838 | expand_cleanups (TREE_VALUE (tail), dont_do); | |
3839 | else | |
3840 | { | |
3841 | /* Cleanups may be run multiple times. For example, | |
3842 | when exiting a binding contour, we expand the | |
3843 | cleanups associated with that contour. When a goto | |
3844 | within that binding contour has a target outside that | |
3845 | contour, it will expand all cleanups from its scope to | |
3846 | the target. Though the cleanups are expanded multiple | |
3847 | times, the control paths are non-overlapping so the | |
3848 | cleanups will not be executed twice. */ | |
3849 | expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0); | |
3850 | free_temp_slots (); | |
3851 | } | |
3852 | } | |
3853 | } | |
3854 | ||
28d81abb RK |
3855 | /* Move all cleanups from the current block_stack |
3856 | to the containing block_stack, where they are assumed to | |
3857 | have been created. If anything can cause a temporary to | |
3858 | be created, but not expanded for more than one level of | |
3859 | block_stacks, then this code will have to change. */ | |
3860 | ||
3861 | void | |
3862 | move_cleanups_up () | |
3863 | { | |
3864 | struct nesting *block = block_stack; | |
3865 | struct nesting *outer = block->next; | |
3866 | ||
3867 | outer->data.block.cleanups | |
3868 | = chainon (block->data.block.cleanups, | |
3869 | outer->data.block.cleanups); | |
3870 | block->data.block.cleanups = 0; | |
3871 | } | |
3872 | ||
3873 | tree | |
3874 | last_cleanup_this_contour () | |
3875 | { | |
3876 | if (block_stack == 0) | |
3877 | return 0; | |
3878 | ||
3879 | return block_stack->data.block.cleanups; | |
3880 | } | |
3881 | ||
3882 | /* Return 1 if there are any pending cleanups at this point. | |
3883 | If THIS_CONTOUR is nonzero, check the current contour as well. | |
3884 | Otherwise, look only at the contours that enclose this one. */ | |
3885 | ||
3886 | int | |
3887 | any_pending_cleanups (this_contour) | |
3888 | int this_contour; | |
3889 | { | |
3890 | struct nesting *block; | |
3891 | ||
3892 | if (block_stack == 0) | |
3893 | return 0; | |
3894 | ||
3895 | if (this_contour && block_stack->data.block.cleanups != NULL) | |
3896 | return 1; | |
3897 | if (block_stack->data.block.cleanups == 0 | |
3898 | && (block_stack->data.block.outer_cleanups == 0 | |
3899 | #if 0 | |
3900 | || block_stack->data.block.outer_cleanups == empty_cleanup_list | |
3901 | #endif | |
3902 | )) | |
3903 | return 0; | |
3904 | ||
3905 | for (block = block_stack->next; block; block = block->next) | |
3906 | if (block->data.block.cleanups != 0) | |
3907 | return 1; | |
3908 | ||
3909 | return 0; | |
3910 | } | |
3911 | \f | |
3912 | /* Enter a case (Pascal) or switch (C) statement. | |
3913 | Push a block onto case_stack and nesting_stack | |
3914 | to accumulate the case-labels that are seen | |
3915 | and to record the labels generated for the statement. | |
3916 | ||
3917 | EXIT_FLAG is nonzero if `exit_something' should exit this case stmt. | |
3918 | Otherwise, this construct is transparent for `exit_something'. | |
3919 | ||
3920 | EXPR is the index-expression to be dispatched on. | |
3921 | TYPE is its nominal type. We could simply convert EXPR to this type, | |
3922 | but instead we take short cuts. */ | |
3923 | ||
3924 | void | |
3925 | expand_start_case (exit_flag, expr, type, printname) | |
3926 | int exit_flag; | |
3927 | tree expr; | |
3928 | tree type; | |
3929 | char *printname; | |
3930 | { | |
3931 | register struct nesting *thiscase = ALLOC_NESTING (); | |
3932 | ||
3933 | /* Make an entry on case_stack for the case we are entering. */ | |
3934 | ||
3935 | thiscase->next = case_stack; | |
3936 | thiscase->all = nesting_stack; | |
3937 | thiscase->depth = ++nesting_depth; | |
3938 | thiscase->exit_label = exit_flag ? gen_label_rtx () : 0; | |
3939 | thiscase->data.case_stmt.case_list = 0; | |
3940 | thiscase->data.case_stmt.index_expr = expr; | |
3941 | thiscase->data.case_stmt.nominal_type = type; | |
3942 | thiscase->data.case_stmt.default_label = 0; | |
3943 | thiscase->data.case_stmt.num_ranges = 0; | |
3944 | thiscase->data.case_stmt.printname = printname; | |
3945 | thiscase->data.case_stmt.seenlabel = 0; | |
3946 | case_stack = thiscase; | |
3947 | nesting_stack = thiscase; | |
3948 | ||
ca695ac9 JB |
3949 | if (output_bytecode) |
3950 | { | |
3951 | bc_expand_start_case (thiscase, expr, type, printname); | |
3952 | return; | |
3953 | } | |
3954 | ||
28d81abb RK |
3955 | do_pending_stack_adjust (); |
3956 | ||
3957 | /* Make sure case_stmt.start points to something that won't | |
3958 | need any transformation before expand_end_case. */ | |
3959 | if (GET_CODE (get_last_insn ()) != NOTE) | |
37366632 | 3960 | emit_note (NULL_PTR, NOTE_INSN_DELETED); |
28d81abb RK |
3961 | |
3962 | thiscase->data.case_stmt.start = get_last_insn (); | |
3963 | } | |
3964 | ||
ca695ac9 JB |
3965 | |
3966 | /* Enter a case statement. It is assumed that the caller has pushed | |
3967 | the current context onto the case stack. */ | |
3968 | void | |
3969 | bc_expand_start_case (thiscase, expr, type, printname) | |
3970 | struct nesting *thiscase; | |
3971 | tree expr; | |
3972 | tree type; | |
3973 | char *printname; | |
3974 | { | |
3975 | bc_expand_expr (expr); | |
3976 | bc_expand_conversion (TREE_TYPE (expr), type); | |
3977 | ||
3978 | /* For cases, the skip is a place we jump to that's emitted after | |
3979 | the size of the jump table is known. */ | |
3980 | ||
3981 | thiscase->data.case_stmt.skip_label = gen_label_rtx (); | |
3982 | bc_emit_bytecode (jump); | |
c53e9440 | 3983 | bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->data.case_stmt.skip_label)); |
ca695ac9 JB |
3984 | |
3985 | #ifdef DEBUG_PRINT_CODE | |
3986 | fputc ('\n', stderr); | |
3987 | #endif | |
3988 | } | |
3989 | ||
3990 | ||
28d81abb RK |
3991 | /* Start a "dummy case statement" within which case labels are invalid |
3992 | and are not connected to any larger real case statement. | |
3993 | This can be used if you don't want to let a case statement jump | |
3994 | into the middle of certain kinds of constructs. */ | |
3995 | ||
3996 | void | |
3997 | expand_start_case_dummy () | |
3998 | { | |
3999 | register struct nesting *thiscase = ALLOC_NESTING (); | |
4000 | ||
4001 | /* Make an entry on case_stack for the dummy. */ | |
4002 | ||
4003 | thiscase->next = case_stack; | |
4004 | thiscase->all = nesting_stack; | |
4005 | thiscase->depth = ++nesting_depth; | |
4006 | thiscase->exit_label = 0; | |
4007 | thiscase->data.case_stmt.case_list = 0; | |
4008 | thiscase->data.case_stmt.start = 0; | |
4009 | thiscase->data.case_stmt.nominal_type = 0; | |
4010 | thiscase->data.case_stmt.default_label = 0; | |
4011 | thiscase->data.case_stmt.num_ranges = 0; | |
4012 | case_stack = thiscase; | |
4013 | nesting_stack = thiscase; | |
4014 | } | |
4015 | ||
4016 | /* End a dummy case statement. */ | |
4017 | ||
4018 | void | |
4019 | expand_end_case_dummy () | |
4020 | { | |
4021 | POPSTACK (case_stack); | |
4022 | } | |
4023 | ||
4024 | /* Return the data type of the index-expression | |
4025 | of the innermost case statement, or null if none. */ | |
4026 | ||
4027 | tree | |
4028 | case_index_expr_type () | |
4029 | { | |
4030 | if (case_stack) | |
4031 | return TREE_TYPE (case_stack->data.case_stmt.index_expr); | |
4032 | return 0; | |
4033 | } | |
4034 | \f | |
4035 | /* Accumulate one case or default label inside a case or switch statement. | |
4036 | VALUE is the value of the case (a null pointer, for a default label). | |
f52fba84 PE |
4037 | The function CONVERTER, when applied to arguments T and V, |
4038 | converts the value V to the type T. | |
28d81abb RK |
4039 | |
4040 | If not currently inside a case or switch statement, return 1 and do | |
4041 | nothing. The caller will print a language-specific error message. | |
4042 | If VALUE is a duplicate or overlaps, return 2 and do nothing | |
4043 | except store the (first) duplicate node in *DUPLICATE. | |
4044 | If VALUE is out of range, return 3 and do nothing. | |
4045 | If we are jumping into the scope of a cleaup or var-sized array, return 5. | |
4046 | Return 0 on success. | |
4047 | ||
4048 | Extended to handle range statements. */ | |
4049 | ||
4050 | int | |
f52fba84 | 4051 | pushcase (value, converter, label, duplicate) |
28d81abb | 4052 | register tree value; |
f52fba84 | 4053 | tree (*converter) PROTO((tree, tree)); |
28d81abb RK |
4054 | register tree label; |
4055 | tree *duplicate; | |
4056 | { | |
4057 | register struct case_node **l; | |
4058 | register struct case_node *n; | |
4059 | tree index_type; | |
4060 | tree nominal_type; | |
4061 | ||
ca695ac9 JB |
4062 | if (output_bytecode) |
4063 | return bc_pushcase (value, label); | |
4064 | ||
28d81abb RK |
4065 | /* Fail if not inside a real case statement. */ |
4066 | if (! (case_stack && case_stack->data.case_stmt.start)) | |
4067 | return 1; | |
4068 | ||
4069 | if (stack_block_stack | |
4070 | && stack_block_stack->depth > case_stack->depth) | |
4071 | return 5; | |
4072 | ||
4073 | index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr); | |
4074 | nominal_type = case_stack->data.case_stmt.nominal_type; | |
4075 | ||
4076 | /* If the index is erroneous, avoid more problems: pretend to succeed. */ | |
4077 | if (index_type == error_mark_node) | |
4078 | return 0; | |
4079 | ||
4080 | /* Convert VALUE to the type in which the comparisons are nominally done. */ | |
4081 | if (value != 0) | |
f52fba84 | 4082 | value = (*converter) (nominal_type, value); |
28d81abb RK |
4083 | |
4084 | /* If this is the first label, warn if any insns have been emitted. */ | |
4085 | if (case_stack->data.case_stmt.seenlabel == 0) | |
4086 | { | |
4087 | rtx insn; | |
4088 | for (insn = case_stack->data.case_stmt.start; | |
4089 | insn; | |
4090 | insn = NEXT_INSN (insn)) | |
4091 | { | |
4092 | if (GET_CODE (insn) == CODE_LABEL) | |
4093 | break; | |
4094 | if (GET_CODE (insn) != NOTE | |
4095 | && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE)) | |
4096 | { | |
4097 | warning ("unreachable code at beginning of %s", | |
4098 | case_stack->data.case_stmt.printname); | |
4099 | break; | |
4100 | } | |
4101 | } | |
4102 | } | |
4103 | case_stack->data.case_stmt.seenlabel = 1; | |
4104 | ||
4105 | /* Fail if this value is out of range for the actual type of the index | |
4106 | (which may be narrower than NOMINAL_TYPE). */ | |
4107 | if (value != 0 && ! int_fits_type_p (value, index_type)) | |
4108 | return 3; | |
4109 | ||
4110 | /* Fail if this is a duplicate or overlaps another entry. */ | |
4111 | if (value == 0) | |
4112 | { | |
4113 | if (case_stack->data.case_stmt.default_label != 0) | |
4114 | { | |
4115 | *duplicate = case_stack->data.case_stmt.default_label; | |
4116 | return 2; | |
4117 | } | |
4118 | case_stack->data.case_stmt.default_label = label; | |
4119 | } | |
4120 | else | |
4121 | { | |
4122 | /* Find the elt in the chain before which to insert the new value, | |
4123 | to keep the chain sorted in increasing order. | |
4124 | But report an error if this element is a duplicate. */ | |
4125 | for (l = &case_stack->data.case_stmt.case_list; | |
4126 | /* Keep going past elements distinctly less than VALUE. */ | |
4127 | *l != 0 && tree_int_cst_lt ((*l)->high, value); | |
4128 | l = &(*l)->right) | |
4129 | ; | |
4130 | if (*l) | |
4131 | { | |
4132 | /* Element we will insert before must be distinctly greater; | |
4133 | overlap means error. */ | |
4134 | if (! tree_int_cst_lt (value, (*l)->low)) | |
4135 | { | |
4136 | *duplicate = (*l)->code_label; | |
4137 | return 2; | |
4138 | } | |
4139 | } | |
4140 | ||
4141 | /* Add this label to the chain, and succeed. | |
4142 | Copy VALUE so it is on temporary rather than momentary | |
4143 | obstack and will thus survive till the end of the case statement. */ | |
4144 | n = (struct case_node *) oballoc (sizeof (struct case_node)); | |
4145 | n->left = 0; | |
4146 | n->right = *l; | |
4147 | n->high = n->low = copy_node (value); | |
4148 | n->code_label = label; | |
4149 | *l = n; | |
4150 | } | |
4151 | ||
4152 | expand_label (label); | |
4153 | return 0; | |
4154 | } | |
4155 | ||
4156 | /* Like pushcase but this case applies to all values | |
4157 | between VALUE1 and VALUE2 (inclusive). | |
4158 | The return value is the same as that of pushcase | |
4159 | but there is one additional error code: | |
4160 | 4 means the specified range was empty. */ | |
4161 | ||
4162 | int | |
f52fba84 | 4163 | pushcase_range (value1, value2, converter, label, duplicate) |
28d81abb | 4164 | register tree value1, value2; |
f52fba84 | 4165 | tree (*converter) PROTO((tree, tree)); |
28d81abb RK |
4166 | register tree label; |
4167 | tree *duplicate; | |
4168 | { | |
4169 | register struct case_node **l; | |
4170 | register struct case_node *n; | |
4171 | tree index_type; | |
4172 | tree nominal_type; | |
4173 | ||
4174 | /* Fail if not inside a real case statement. */ | |
4175 | if (! (case_stack && case_stack->data.case_stmt.start)) | |
4176 | return 1; | |
4177 | ||
4178 | if (stack_block_stack | |
4179 | && stack_block_stack->depth > case_stack->depth) | |
4180 | return 5; | |
4181 | ||
4182 | index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr); | |
4183 | nominal_type = case_stack->data.case_stmt.nominal_type; | |
4184 | ||
4185 | /* If the index is erroneous, avoid more problems: pretend to succeed. */ | |
4186 | if (index_type == error_mark_node) | |
4187 | return 0; | |
4188 | ||
4189 | /* If this is the first label, warn if any insns have been emitted. */ | |
4190 | if (case_stack->data.case_stmt.seenlabel == 0) | |
4191 | { | |
4192 | rtx insn; | |
4193 | for (insn = case_stack->data.case_stmt.start; | |
4194 | insn; | |
4195 | insn = NEXT_INSN (insn)) | |
4196 | { | |
4197 | if (GET_CODE (insn) == CODE_LABEL) | |
4198 | break; | |
4199 | if (GET_CODE (insn) != NOTE | |
4200 | && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE)) | |
4201 | { | |
4202 | warning ("unreachable code at beginning of %s", | |
4203 | case_stack->data.case_stmt.printname); | |
4204 | break; | |
4205 | } | |
4206 | } | |
4207 | } | |
4208 | case_stack->data.case_stmt.seenlabel = 1; | |
4209 | ||
4210 | /* Convert VALUEs to type in which the comparisons are nominally done. */ | |
4211 | if (value1 == 0) /* Negative infinity. */ | |
4212 | value1 = TYPE_MIN_VALUE(index_type); | |
f52fba84 | 4213 | value1 = (*converter) (nominal_type, value1); |
28d81abb RK |
4214 | |
4215 | if (value2 == 0) /* Positive infinity. */ | |
4216 | value2 = TYPE_MAX_VALUE(index_type); | |
f52fba84 | 4217 | value2 = (*converter) (nominal_type, value2); |
28d81abb RK |
4218 | |
4219 | /* Fail if these values are out of range. */ | |
4220 | if (! int_fits_type_p (value1, index_type)) | |
4221 | return 3; | |
4222 | ||
4223 | if (! int_fits_type_p (value2, index_type)) | |
4224 | return 3; | |
4225 | ||
4226 | /* Fail if the range is empty. */ | |
4227 | if (tree_int_cst_lt (value2, value1)) | |
4228 | return 4; | |
4229 | ||
4230 | /* If the bounds are equal, turn this into the one-value case. */ | |
4231 | if (tree_int_cst_equal (value1, value2)) | |
f52fba84 | 4232 | return pushcase (value1, converter, label, duplicate); |
28d81abb RK |
4233 | |
4234 | /* Find the elt in the chain before which to insert the new value, | |
4235 | to keep the chain sorted in increasing order. | |
4236 | But report an error if this element is a duplicate. */ | |
4237 | for (l = &case_stack->data.case_stmt.case_list; | |
4238 | /* Keep going past elements distinctly less than this range. */ | |
4239 | *l != 0 && tree_int_cst_lt ((*l)->high, value1); | |
4240 | l = &(*l)->right) | |
4241 | ; | |
4242 | if (*l) | |
4243 | { | |
4244 | /* Element we will insert before must be distinctly greater; | |
4245 | overlap means error. */ | |
4246 | if (! tree_int_cst_lt (value2, (*l)->low)) | |
4247 | { | |
4248 | *duplicate = (*l)->code_label; | |
4249 | return 2; | |
4250 | } | |
4251 | } | |
4252 | ||
4253 | /* Add this label to the chain, and succeed. | |
4254 | Copy VALUE1, VALUE2 so they are on temporary rather than momentary | |
4255 | obstack and will thus survive till the end of the case statement. */ | |
4256 | ||
4257 | n = (struct case_node *) oballoc (sizeof (struct case_node)); | |
4258 | n->left = 0; | |
4259 | n->right = *l; | |
4260 | n->low = copy_node (value1); | |
4261 | n->high = copy_node (value2); | |
4262 | n->code_label = label; | |
4263 | *l = n; | |
4264 | ||
4265 | expand_label (label); | |
4266 | ||
4267 | case_stack->data.case_stmt.num_ranges++; | |
4268 | ||
4269 | return 0; | |
4270 | } | |
ca695ac9 JB |
4271 | |
4272 | ||
4273 | /* Accumulate one case or default label; VALUE is the value of the | |
4274 | case, or nil for a default label. If not currently inside a case, | |
4275 | return 1 and do nothing. If VALUE is a duplicate or overlaps, return | |
4276 | 2 and do nothing. If VALUE is out of range, return 3 and do nothing. | |
4277 | Return 0 on success. This function is a leftover from the earlier | |
4278 | bytecode compiler, which was based on gcc 1.37. It should be | |
4279 | merged into pushcase. */ | |
4280 | ||
4281 | int | |
4282 | bc_pushcase (value, label) | |
4283 | tree value; | |
4284 | tree label; | |
4285 | { | |
4286 | struct nesting *thiscase = case_stack; | |
4287 | struct case_node *case_label, *new_label; | |
4288 | ||
4289 | if (! thiscase) | |
4290 | return 1; | |
4291 | ||
4292 | /* Fail if duplicate, overlap, or out of type range. */ | |
4293 | if (value) | |
4294 | { | |
4295 | value = convert (thiscase->data.case_stmt.nominal_type, value); | |
4296 | if (! int_fits_type_p (value, thiscase->data.case_stmt.nominal_type)) | |
4297 | return 3; | |
4298 | ||
4299 | for (case_label = thiscase->data.case_stmt.case_list; | |
4300 | case_label->left; case_label = case_label->left) | |
4301 | if (! tree_int_cst_lt (case_label->left->high, value)) | |
4302 | break; | |
4303 | ||
4304 | if (case_label != thiscase->data.case_stmt.case_list | |
4305 | && ! tree_int_cst_lt (case_label->high, value) | |
4306 | || case_label->left && ! tree_int_cst_lt (value, case_label->left->low)) | |
4307 | return 2; | |
4308 | ||
4309 | new_label = (struct case_node *) oballoc (sizeof (struct case_node)); | |
4310 | new_label->low = new_label->high = copy_node (value); | |
4311 | new_label->code_label = label; | |
4312 | new_label->left = case_label->left; | |
4313 | ||
4314 | case_label->left = new_label; | |
4315 | thiscase->data.case_stmt.num_ranges++; | |
4316 | } | |
4317 | else | |
4318 | { | |
4319 | if (thiscase->data.case_stmt.default_label) | |
4320 | return 2; | |
4321 | thiscase->data.case_stmt.default_label = label; | |
4322 | } | |
4323 | ||
4324 | expand_label (label); | |
4325 | return 0; | |
4326 | } | |
28d81abb RK |
4327 | \f |
4328 | /* Called when the index of a switch statement is an enumerated type | |
4329 | and there is no default label. | |
4330 | ||
4331 | Checks that all enumeration literals are covered by the case | |
4332 | expressions of a switch. Also, warn if there are any extra | |
4333 | switch cases that are *not* elements of the enumerated type. | |
4334 | ||
4335 | If all enumeration literals were covered by the case expressions, | |
4336 | turn one of the expressions into the default expression since it should | |
4337 | not be possible to fall through such a switch. */ | |
4338 | ||
4339 | void | |
4340 | check_for_full_enumeration_handling (type) | |
4341 | tree type; | |
4342 | { | |
4343 | register struct case_node *n; | |
4344 | register struct case_node **l; | |
4345 | register tree chain; | |
4346 | int all_values = 1; | |
4347 | ||
ca695ac9 JB |
4348 | if (output_bytecode) |
4349 | { | |
4350 | bc_check_for_full_enumeration_handling (type); | |
4351 | return; | |
4352 | } | |
4353 | ||
28d81abb | 4354 | /* The time complexity of this loop is currently O(N * M), with |
ac2a9454 | 4355 | N being the number of members in the enumerated type, and |
28d81abb RK |
4356 | M being the number of case expressions in the switch. */ |
4357 | ||
4358 | for (chain = TYPE_VALUES (type); | |
4359 | chain; | |
4360 | chain = TREE_CHAIN (chain)) | |
4361 | { | |
4362 | /* Find a match between enumeral and case expression, if possible. | |
4363 | Quit looking when we've gone too far (since case expressions | |
ac2a9454 | 4364 | are kept sorted in ascending order). Warn about enumerators not |
28d81abb RK |
4365 | handled in the switch statement case expression list. */ |
4366 | ||
4367 | for (n = case_stack->data.case_stmt.case_list; | |
4368 | n && tree_int_cst_lt (n->high, TREE_VALUE (chain)); | |
4369 | n = n->right) | |
4370 | ; | |
4371 | ||
1ddde1cd | 4372 | if (!n || tree_int_cst_lt (TREE_VALUE (chain), n->low)) |
28d81abb RK |
4373 | { |
4374 | if (warn_switch) | |
1ddde1cd | 4375 | warning ("enumeration value `%s' not handled in switch", |
28d81abb RK |
4376 | IDENTIFIER_POINTER (TREE_PURPOSE (chain))); |
4377 | all_values = 0; | |
4378 | } | |
4379 | } | |
4380 | ||
4381 | /* Now we go the other way around; we warn if there are case | |
ac2a9454 | 4382 | expressions that don't correspond to enumerators. This can |
28d81abb RK |
4383 | occur since C and C++ don't enforce type-checking of |
4384 | assignments to enumeration variables. */ | |
4385 | ||
4386 | if (warn_switch) | |
4387 | for (n = case_stack->data.case_stmt.case_list; n; n = n->right) | |
4388 | { | |
4389 | for (chain = TYPE_VALUES (type); | |
4390 | chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain)); | |
4391 | chain = TREE_CHAIN (chain)) | |
4392 | ; | |
4393 | ||
4394 | if (!chain) | |
3b24f55b RS |
4395 | { |
4396 | if (TYPE_NAME (type) == 0) | |
4397 | warning ("case value `%d' not in enumerated type", | |
4398 | TREE_INT_CST_LOW (n->low)); | |
4399 | else | |
4400 | warning ("case value `%d' not in enumerated type `%s'", | |
4401 | TREE_INT_CST_LOW (n->low), | |
4402 | IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type)) | |
4403 | == IDENTIFIER_NODE) | |
4404 | ? TYPE_NAME (type) | |
4405 | : DECL_NAME (TYPE_NAME (type)))); | |
4406 | } | |
1ddde1cd RS |
4407 | if (!tree_int_cst_equal (n->low, n->high)) |
4408 | { | |
4409 | for (chain = TYPE_VALUES (type); | |
4410 | chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain)); | |
4411 | chain = TREE_CHAIN (chain)) | |
4412 | ; | |
4413 | ||
4414 | if (!chain) | |
3b24f55b RS |
4415 | { |
4416 | if (TYPE_NAME (type) == 0) | |
4417 | warning ("case value `%d' not in enumerated type", | |
4418 | TREE_INT_CST_LOW (n->high)); | |
4419 | else | |
4420 | warning ("case value `%d' not in enumerated type `%s'", | |
4421 | TREE_INT_CST_LOW (n->high), | |
4422 | IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type)) | |
4423 | == IDENTIFIER_NODE) | |
4424 | ? TYPE_NAME (type) | |
4425 | : DECL_NAME (TYPE_NAME (type)))); | |
4426 | } | |
1ddde1cd | 4427 | } |
28d81abb RK |
4428 | } |
4429 | ||
ae8cb346 RS |
4430 | #if 0 |
4431 | /* ??? This optimization is disabled because it causes valid programs to | |
4432 | fail. ANSI C does not guarantee that an expression with enum type | |
4433 | will have a value that is the same as one of the enumation literals. */ | |
4434 | ||
28d81abb RK |
4435 | /* If all values were found as case labels, make one of them the default |
4436 | label. Thus, this switch will never fall through. We arbitrarily pick | |
4437 | the last one to make the default since this is likely the most | |
4438 | efficient choice. */ | |
4439 | ||
4440 | if (all_values) | |
4441 | { | |
4442 | for (l = &case_stack->data.case_stmt.case_list; | |
4443 | (*l)->right != 0; | |
4444 | l = &(*l)->right) | |
4445 | ; | |
4446 | ||
4447 | case_stack->data.case_stmt.default_label = (*l)->code_label; | |
4448 | *l = 0; | |
4449 | } | |
ae8cb346 | 4450 | #endif /* 0 */ |
28d81abb | 4451 | } |
ca695ac9 JB |
4452 | |
4453 | ||
4454 | /* Check that all enumeration literals are covered by the case | |
4455 | expressions of a switch. Also warn if there are any cases | |
4456 | that are not elements of the enumerated type. */ | |
4457 | void | |
4458 | bc_check_for_full_enumeration_handling (type) | |
4459 | tree type; | |
4460 | { | |
4461 | struct nesting *thiscase = case_stack; | |
4462 | struct case_node *c; | |
4463 | tree e; | |
4464 | ||
4465 | /* Check for enums not handled. */ | |
4466 | for (e = TYPE_VALUES (type); e; e = TREE_CHAIN (e)) | |
4467 | { | |
4468 | for (c = thiscase->data.case_stmt.case_list->left; | |
4469 | c && tree_int_cst_lt (c->high, TREE_VALUE (e)); | |
4470 | c = c->left) | |
4471 | ; | |
4472 | if (! (c && tree_int_cst_equal (c->low, TREE_VALUE (e)))) | |
4473 | warning ("enumerated value `%s' not handled in switch", | |
4474 | IDENTIFIER_POINTER (TREE_PURPOSE (e))); | |
4475 | } | |
4476 | ||
4477 | /* Check for cases not in the enumeration. */ | |
4478 | for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left) | |
4479 | { | |
4480 | for (e = TYPE_VALUES (type); | |
4481 | e && !tree_int_cst_equal (c->low, TREE_VALUE (e)); | |
4482 | e = TREE_CHAIN (e)) | |
4483 | ; | |
4484 | if (! e) | |
4485 | warning ("case value `%d' not in enumerated type `%s'", | |
4486 | TREE_INT_CST_LOW (c->low), | |
4487 | IDENTIFIER_POINTER (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE | |
4488 | ? TYPE_NAME (type) | |
4489 | : DECL_NAME (TYPE_NAME (type)))); | |
4490 | } | |
4491 | } | |
28d81abb RK |
4492 | \f |
4493 | /* Terminate a case (Pascal) or switch (C) statement | |
9ab0ddd7 | 4494 | in which ORIG_INDEX is the expression to be tested. |
28d81abb RK |
4495 | Generate the code to test it and jump to the right place. */ |
4496 | ||
4497 | void | |
4498 | expand_end_case (orig_index) | |
4499 | tree orig_index; | |
4500 | { | |
3474db0e | 4501 | tree minval, maxval, range, orig_minval; |
28d81abb RK |
4502 | rtx default_label = 0; |
4503 | register struct case_node *n; | |
4504 | int count; | |
4505 | rtx index; | |
ca695ac9 | 4506 | rtx table_label; |
28d81abb RK |
4507 | int ncases; |
4508 | rtx *labelvec; | |
4509 | register int i; | |
4510 | rtx before_case; | |
4511 | register struct nesting *thiscase = case_stack; | |
ca695ac9 JB |
4512 | tree index_expr; |
4513 | int unsignedp; | |
4514 | ||
4515 | if (output_bytecode) | |
4516 | { | |
4517 | bc_expand_end_case (orig_index); | |
4518 | return; | |
4519 | } | |
4520 | ||
4521 | table_label = gen_label_rtx (); | |
4522 | index_expr = thiscase->data.case_stmt.index_expr; | |
4523 | unsignedp = TREE_UNSIGNED (TREE_TYPE (index_expr)); | |
28d81abb RK |
4524 | |
4525 | do_pending_stack_adjust (); | |
4526 | ||
4527 | /* An ERROR_MARK occurs for various reasons including invalid data type. */ | |
4528 | if (TREE_TYPE (index_expr) != error_mark_node) | |
4529 | { | |
4530 | /* If switch expression was an enumerated type, check that all | |
4531 | enumeration literals are covered by the cases. | |
4532 | No sense trying this if there's a default case, however. */ | |
4533 | ||
4534 | if (!thiscase->data.case_stmt.default_label | |
4535 | && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE | |
4536 | && TREE_CODE (index_expr) != INTEGER_CST) | |
4537 | check_for_full_enumeration_handling (TREE_TYPE (orig_index)); | |
4538 | ||
4539 | /* If this is the first label, warn if any insns have been emitted. */ | |
4540 | if (thiscase->data.case_stmt.seenlabel == 0) | |
4541 | { | |
4542 | rtx insn; | |
4543 | for (insn = get_last_insn (); | |
4544 | insn != case_stack->data.case_stmt.start; | |
4545 | insn = PREV_INSN (insn)) | |
4546 | if (GET_CODE (insn) != NOTE | |
4547 | && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn))!= USE)) | |
4548 | { | |
4549 | warning ("unreachable code at beginning of %s", | |
4550 | case_stack->data.case_stmt.printname); | |
4551 | break; | |
4552 | } | |
4553 | } | |
4554 | ||
4555 | /* If we don't have a default-label, create one here, | |
4556 | after the body of the switch. */ | |
4557 | if (thiscase->data.case_stmt.default_label == 0) | |
4558 | { | |
4559 | thiscase->data.case_stmt.default_label | |
4560 | = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE); | |
4561 | expand_label (thiscase->data.case_stmt.default_label); | |
4562 | } | |
4563 | default_label = label_rtx (thiscase->data.case_stmt.default_label); | |
4564 | ||
4565 | before_case = get_last_insn (); | |
4566 | ||
4567 | /* Simplify the case-list before we count it. */ | |
4568 | group_case_nodes (thiscase->data.case_stmt.case_list); | |
4569 | ||
4570 | /* Get upper and lower bounds of case values. | |
4571 | Also convert all the case values to the index expr's data type. */ | |
4572 | ||
4573 | count = 0; | |
4574 | for (n = thiscase->data.case_stmt.case_list; n; n = n->right) | |
4575 | { | |
4576 | /* Check low and high label values are integers. */ | |
4577 | if (TREE_CODE (n->low) != INTEGER_CST) | |
4578 | abort (); | |
4579 | if (TREE_CODE (n->high) != INTEGER_CST) | |
4580 | abort (); | |
4581 | ||
4582 | n->low = convert (TREE_TYPE (index_expr), n->low); | |
4583 | n->high = convert (TREE_TYPE (index_expr), n->high); | |
4584 | ||
4585 | /* Count the elements and track the largest and smallest | |
4586 | of them (treating them as signed even if they are not). */ | |
4587 | if (count++ == 0) | |
4588 | { | |
4589 | minval = n->low; | |
4590 | maxval = n->high; | |
4591 | } | |
4592 | else | |
4593 | { | |
4594 | if (INT_CST_LT (n->low, minval)) | |
4595 | minval = n->low; | |
4596 | if (INT_CST_LT (maxval, n->high)) | |
4597 | maxval = n->high; | |
4598 | } | |
4599 | /* A range counts double, since it requires two compares. */ | |
4600 | if (! tree_int_cst_equal (n->low, n->high)) | |
4601 | count++; | |
4602 | } | |
4603 | ||
3474db0e RS |
4604 | orig_minval = minval; |
4605 | ||
28d81abb RK |
4606 | /* Compute span of values. */ |
4607 | if (count != 0) | |
4608 | range = fold (build (MINUS_EXPR, TREE_TYPE (index_expr), | |
4609 | maxval, minval)); | |
4610 | ||
4611 | if (count == 0 || TREE_CODE (TREE_TYPE (index_expr)) == ERROR_MARK) | |
4612 | { | |
4613 | expand_expr (index_expr, const0_rtx, VOIDmode, 0); | |
4614 | emit_queue (); | |
4615 | emit_jump (default_label); | |
4616 | } | |
3474db0e | 4617 | |
28d81abb RK |
4618 | /* If range of values is much bigger than number of values, |
4619 | make a sequence of conditional branches instead of a dispatch. | |
4620 | If the switch-index is a constant, do it this way | |
4621 | because we can optimize it. */ | |
4f73c5dd TW |
4622 | |
4623 | #ifndef CASE_VALUES_THRESHOLD | |
28d81abb | 4624 | #ifdef HAVE_casesi |
4f73c5dd | 4625 | #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5) |
28d81abb | 4626 | #else |
4f73c5dd TW |
4627 | /* If machine does not have a case insn that compares the |
4628 | bounds, this means extra overhead for dispatch tables | |
4629 | which raises the threshold for using them. */ | |
4630 | #define CASE_VALUES_THRESHOLD 5 | |
4631 | #endif /* HAVE_casesi */ | |
4632 | #endif /* CASE_VALUES_THRESHOLD */ | |
4633 | ||
4634 | else if (TREE_INT_CST_HIGH (range) != 0 | |
4635 | || count < CASE_VALUES_THRESHOLD | |
37366632 RK |
4636 | || ((unsigned HOST_WIDE_INT) (TREE_INT_CST_LOW (range)) |
4637 | > 10 * count) | |
28d81abb | 4638 | || TREE_CODE (index_expr) == INTEGER_CST |
b4ac57ab | 4639 | /* These will reduce to a constant. */ |
28d81abb | 4640 | || (TREE_CODE (index_expr) == CALL_EXPR |
de14fd73 | 4641 | && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR |
28d81abb | 4642 | && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL |
b4ac57ab RS |
4643 | && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE) |
4644 | || (TREE_CODE (index_expr) == COMPOUND_EXPR | |
4645 | && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST)) | |
28d81abb | 4646 | { |
37366632 | 4647 | index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0); |
28d81abb RK |
4648 | |
4649 | /* If the index is a short or char that we do not have | |
4650 | an insn to handle comparisons directly, convert it to | |
4651 | a full integer now, rather than letting each comparison | |
4652 | generate the conversion. */ | |
4653 | ||
4654 | if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT | |
4655 | && (cmp_optab->handlers[(int) GET_MODE(index)].insn_code | |
4656 | == CODE_FOR_nothing)) | |
4657 | { | |
4658 | enum machine_mode wider_mode; | |
4659 | for (wider_mode = GET_MODE (index); wider_mode != VOIDmode; | |
4660 | wider_mode = GET_MODE_WIDER_MODE (wider_mode)) | |
4661 | if (cmp_optab->handlers[(int) wider_mode].insn_code | |
4662 | != CODE_FOR_nothing) | |
4663 | { | |
4664 | index = convert_to_mode (wider_mode, index, unsignedp); | |
4665 | break; | |
4666 | } | |
4667 | } | |
4668 | ||
4669 | emit_queue (); | |
4670 | do_pending_stack_adjust (); | |
4671 | ||
4672 | index = protect_from_queue (index, 0); | |
4673 | if (GET_CODE (index) == MEM) | |
4674 | index = copy_to_reg (index); | |
4675 | if (GET_CODE (index) == CONST_INT | |
4676 | || TREE_CODE (index_expr) == INTEGER_CST) | |
4677 | { | |
4678 | /* Make a tree node with the proper constant value | |
4679 | if we don't already have one. */ | |
4680 | if (TREE_CODE (index_expr) != INTEGER_CST) | |
4681 | { | |
4682 | index_expr | |
4683 | = build_int_2 (INTVAL (index), | |
4684 | !unsignedp && INTVAL (index) >= 0 ? 0 : -1); | |
4685 | index_expr = convert (TREE_TYPE (index_expr), index_expr); | |
4686 | } | |
4687 | ||
4688 | /* For constant index expressions we need only | |
4689 | issue a unconditional branch to the appropriate | |
4690 | target code. The job of removing any unreachable | |
4691 | code is left to the optimisation phase if the | |
4692 | "-O" option is specified. */ | |
4693 | for (n = thiscase->data.case_stmt.case_list; | |
4694 | n; | |
4695 | n = n->right) | |
4696 | { | |
4697 | if (! tree_int_cst_lt (index_expr, n->low) | |
4698 | && ! tree_int_cst_lt (n->high, index_expr)) | |
4699 | break; | |
4700 | } | |
4701 | if (n) | |
4702 | emit_jump (label_rtx (n->code_label)); | |
4703 | else | |
4704 | emit_jump (default_label); | |
4705 | } | |
4706 | else | |
4707 | { | |
4708 | /* If the index expression is not constant we generate | |
4709 | a binary decision tree to select the appropriate | |
4710 | target code. This is done as follows: | |
4711 | ||
4712 | The list of cases is rearranged into a binary tree, | |
4713 | nearly optimal assuming equal probability for each case. | |
4714 | ||
4715 | The tree is transformed into RTL, eliminating | |
4716 | redundant test conditions at the same time. | |
4717 | ||
4718 | If program flow could reach the end of the | |
4719 | decision tree an unconditional jump to the | |
4720 | default code is emitted. */ | |
4721 | ||
4722 | use_cost_table | |
4723 | = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE | |
28d81abb | 4724 | && estimate_case_costs (thiscase->data.case_stmt.case_list)); |
37366632 RK |
4725 | balance_case_nodes (&thiscase->data.case_stmt.case_list, |
4726 | NULL_PTR); | |
28d81abb RK |
4727 | emit_case_nodes (index, thiscase->data.case_stmt.case_list, |
4728 | default_label, TREE_TYPE (index_expr)); | |
4729 | emit_jump_if_reachable (default_label); | |
4730 | } | |
4731 | } | |
4732 | else | |
4733 | { | |
4734 | int win = 0; | |
4735 | #ifdef HAVE_casesi | |
4736 | if (HAVE_casesi) | |
4737 | { | |
c4fcf531 | 4738 | enum machine_mode index_mode = SImode; |
5130a5cc | 4739 | int index_bits = GET_MODE_BITSIZE (index_mode); |
c4fcf531 | 4740 | |
28d81abb | 4741 | /* Convert the index to SImode. */ |
c4fcf531 RS |
4742 | if (GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (index_expr))) |
4743 | > GET_MODE_BITSIZE (index_mode)) | |
28d81abb | 4744 | { |
af2682ef | 4745 | enum machine_mode omode = TYPE_MODE (TREE_TYPE (index_expr)); |
37366632 | 4746 | rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0); |
af2682ef RS |
4747 | |
4748 | /* We must handle the endpoints in the original mode. */ | |
28d81abb RK |
4749 | index_expr = build (MINUS_EXPR, TREE_TYPE (index_expr), |
4750 | index_expr, minval); | |
4751 | minval = integer_zero_node; | |
37366632 | 4752 | index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0); |
3474db0e | 4753 | emit_cmp_insn (rangertx, index, LTU, NULL_RTX, omode, 1, 0); |
af2682ef RS |
4754 | emit_jump_insn (gen_bltu (default_label)); |
4755 | /* Now we can safely truncate. */ | |
4756 | index = convert_to_mode (index_mode, index, 0); | |
4757 | } | |
4758 | else | |
4759 | { | |
4760 | if (TYPE_MODE (TREE_TYPE (index_expr)) != index_mode) | |
4761 | index_expr = convert (type_for_size (index_bits, 0), | |
4762 | index_expr); | |
37366632 | 4763 | index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0); |
28d81abb | 4764 | } |
28d81abb RK |
4765 | emit_queue (); |
4766 | index = protect_from_queue (index, 0); | |
4767 | do_pending_stack_adjust (); | |
4768 | ||
37366632 RK |
4769 | emit_jump_insn (gen_casesi (index, expand_expr (minval, NULL_RTX, |
4770 | VOIDmode, 0), | |
4771 | expand_expr (range, NULL_RTX, | |
4772 | VOIDmode, 0), | |
28d81abb RK |
4773 | table_label, default_label)); |
4774 | win = 1; | |
4775 | } | |
4776 | #endif | |
4777 | #ifdef HAVE_tablejump | |
4778 | if (! win && HAVE_tablejump) | |
4779 | { | |
4780 | index_expr = convert (thiscase->data.case_stmt.nominal_type, | |
b4ac57ab RS |
4781 | fold (build (MINUS_EXPR, |
4782 | TREE_TYPE (index_expr), | |
4783 | index_expr, minval))); | |
37366632 | 4784 | index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0); |
28d81abb | 4785 | emit_queue (); |
af2682ef | 4786 | index = protect_from_queue (index, 0); |
28d81abb RK |
4787 | do_pending_stack_adjust (); |
4788 | ||
af2682ef | 4789 | do_tablejump (index, TYPE_MODE (TREE_TYPE (index_expr)), |
37366632 | 4790 | expand_expr (range, NULL_RTX, VOIDmode, 0), |
28d81abb RK |
4791 | table_label, default_label); |
4792 | win = 1; | |
4793 | } | |
4794 | #endif | |
4795 | if (! win) | |
4796 | abort (); | |
4797 | ||
4798 | /* Get table of labels to jump to, in order of case index. */ | |
4799 | ||
4800 | ncases = TREE_INT_CST_LOW (range) + 1; | |
4801 | labelvec = (rtx *) alloca (ncases * sizeof (rtx)); | |
4802 | bzero (labelvec, ncases * sizeof (rtx)); | |
4803 | ||
4804 | for (n = thiscase->data.case_stmt.case_list; n; n = n->right) | |
4805 | { | |
37366632 | 4806 | register HOST_WIDE_INT i |
3474db0e | 4807 | = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval); |
28d81abb RK |
4808 | |
4809 | while (1) | |
4810 | { | |
4811 | labelvec[i] | |
4812 | = gen_rtx (LABEL_REF, Pmode, label_rtx (n->code_label)); | |
3474db0e | 4813 | if (i + TREE_INT_CST_LOW (orig_minval) |
28d81abb RK |
4814 | == TREE_INT_CST_LOW (n->high)) |
4815 | break; | |
4816 | i++; | |
4817 | } | |
4818 | } | |
4819 | ||
4820 | /* Fill in the gaps with the default. */ | |
4821 | for (i = 0; i < ncases; i++) | |
4822 | if (labelvec[i] == 0) | |
4823 | labelvec[i] = gen_rtx (LABEL_REF, Pmode, default_label); | |
4824 | ||
4825 | /* Output the table */ | |
4826 | emit_label (table_label); | |
4827 | ||
4828 | /* This would be a lot nicer if CASE_VECTOR_PC_RELATIVE | |
858a47b1 | 4829 | were an expression, instead of an #ifdef/#ifndef. */ |
28d81abb RK |
4830 | if ( |
4831 | #ifdef CASE_VECTOR_PC_RELATIVE | |
4832 | 1 || | |
4833 | #endif | |
4834 | flag_pic) | |
4835 | emit_jump_insn (gen_rtx (ADDR_DIFF_VEC, CASE_VECTOR_MODE, | |
4836 | gen_rtx (LABEL_REF, Pmode, table_label), | |
4837 | gen_rtvec_v (ncases, labelvec))); | |
4838 | else | |
4839 | emit_jump_insn (gen_rtx (ADDR_VEC, CASE_VECTOR_MODE, | |
4840 | gen_rtvec_v (ncases, labelvec))); | |
4841 | ||
4842 | /* If the case insn drops through the table, | |
4843 | after the table we must jump to the default-label. | |
4844 | Otherwise record no drop-through after the table. */ | |
4845 | #ifdef CASE_DROPS_THROUGH | |
4846 | emit_jump (default_label); | |
4847 | #else | |
4848 | emit_barrier (); | |
4849 | #endif | |
4850 | } | |
4851 | ||
915f619f JW |
4852 | before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ()); |
4853 | reorder_insns (before_case, get_last_insn (), | |
28d81abb RK |
4854 | thiscase->data.case_stmt.start); |
4855 | } | |
4856 | if (thiscase->exit_label) | |
4857 | emit_label (thiscase->exit_label); | |
4858 | ||
4859 | POPSTACK (case_stack); | |
4860 | ||
4861 | free_temp_slots (); | |
4862 | } | |
4863 | ||
ca695ac9 JB |
4864 | |
4865 | /* Terminate a case statement. EXPR is the original index | |
4866 | expression. */ | |
4867 | void | |
4868 | bc_expand_end_case (expr) | |
4869 | tree expr; | |
4870 | { | |
4871 | struct nesting *thiscase = case_stack; | |
4872 | enum bytecode_opcode opcode; | |
4873 | struct bc_label *jump_label; | |
4874 | struct case_node *c; | |
4875 | ||
4876 | bc_emit_bytecode (jump); | |
c53e9440 | 4877 | bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->exit_label)); |
ca695ac9 JB |
4878 | |
4879 | #ifdef DEBUG_PRINT_CODE | |
4880 | fputc ('\n', stderr); | |
4881 | #endif | |
4882 | ||
4883 | /* Now that the size of the jump table is known, emit the actual | |
4884 | indexed jump instruction. */ | |
c53e9440 | 4885 | bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscase->data.case_stmt.skip_label)); |
ca695ac9 JB |
4886 | |
4887 | opcode = TYPE_MODE (thiscase->data.case_stmt.nominal_type) == SImode | |
4888 | ? TREE_UNSIGNED (thiscase->data.case_stmt.nominal_type) ? caseSU : caseSI | |
4889 | : TREE_UNSIGNED (thiscase->data.case_stmt.nominal_type) ? caseDU : caseDI; | |
4890 | ||
4891 | bc_emit_bytecode (opcode); | |
4892 | ||
4893 | /* Now emit the case instructions literal arguments, in order. | |
4894 | In addition to the value on the stack, it uses: | |
4895 | 1. The address of the jump table. | |
4896 | 2. The size of the jump table. | |
4897 | 3. The default label. */ | |
4898 | ||
4899 | jump_label = bc_get_bytecode_label (); | |
4900 | bc_emit_bytecode_labelref (jump_label); | |
4901 | bc_emit_bytecode_const ((char *) &thiscase->data.case_stmt.num_ranges, | |
4902 | sizeof thiscase->data.case_stmt.num_ranges); | |
4903 | ||
4904 | if (thiscase->data.case_stmt.default_label) | |
c53e9440 | 4905 | bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (thiscase->data.case_stmt.default_label))); |
ca695ac9 | 4906 | else |
c53e9440 | 4907 | bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->exit_label)); |
ca695ac9 JB |
4908 | |
4909 | /* Output the jump table. */ | |
4910 | ||
4911 | bc_align_bytecode (3 /* PTR_ALIGN */); | |
4912 | bc_emit_bytecode_labeldef (jump_label); | |
4913 | ||
4914 | if (TYPE_MODE (thiscase->data.case_stmt.nominal_type) == SImode) | |
4915 | for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left) | |
4916 | { | |
4917 | opcode = TREE_INT_CST_LOW (c->low); | |
4918 | bc_emit_bytecode_const ((char *) &opcode, sizeof opcode); | |
4919 | ||
4920 | opcode = TREE_INT_CST_LOW (c->high); | |
4921 | bc_emit_bytecode_const ((char *) &opcode, sizeof opcode); | |
4922 | ||
c53e9440 | 4923 | bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (c->code_label))); |
ca695ac9 JB |
4924 | } |
4925 | else | |
4926 | if (TYPE_MODE (thiscase->data.case_stmt.nominal_type) == DImode) | |
4927 | for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left) | |
4928 | { | |
4929 | bc_emit_bytecode_DI_const (c->low); | |
4930 | bc_emit_bytecode_DI_const (c->high); | |
4931 | ||
c53e9440 | 4932 | bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (c->code_label))); |
ca695ac9 JB |
4933 | } |
4934 | else | |
4935 | /* Bad mode */ | |
4936 | abort (); | |
4937 | ||
4938 | ||
c53e9440 | 4939 | bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscase->exit_label)); |
ca695ac9 JB |
4940 | |
4941 | /* Possibly issue enumeration warnings. */ | |
4942 | ||
4943 | if (!thiscase->data.case_stmt.default_label | |
4944 | && TREE_CODE (TREE_TYPE (expr)) == ENUMERAL_TYPE | |
4945 | && TREE_CODE (expr) != INTEGER_CST | |
4946 | && warn_switch) | |
4947 | check_for_full_enumeration_handling (TREE_TYPE (expr)); | |
4948 | ||
4949 | ||
4950 | #ifdef DEBUG_PRINT_CODE | |
4951 | fputc ('\n', stderr); | |
4952 | #endif | |
4953 | ||
4954 | POPSTACK (case_stack); | |
4955 | } | |
4956 | ||
4957 | ||
4958 | /* Return unique bytecode ID. */ | |
4959 | int | |
4960 | bc_new_uid () | |
4961 | { | |
4962 | static int bc_uid = 0; | |
4963 | ||
4964 | return (++bc_uid); | |
4965 | } | |
4966 | ||
28d81abb RK |
4967 | /* Generate code to jump to LABEL if OP1 and OP2 are equal. */ |
4968 | ||
4969 | static void | |
4970 | do_jump_if_equal (op1, op2, label, unsignedp) | |
4971 | rtx op1, op2, label; | |
4972 | int unsignedp; | |
4973 | { | |
4974 | if (GET_CODE (op1) == CONST_INT | |
4975 | && GET_CODE (op2) == CONST_INT) | |
4976 | { | |
4977 | if (INTVAL (op1) == INTVAL (op2)) | |
4978 | emit_jump (label); | |
4979 | } | |
4980 | else | |
4981 | { | |
4982 | enum machine_mode mode = GET_MODE (op1); | |
4983 | if (mode == VOIDmode) | |
4984 | mode = GET_MODE (op2); | |
37366632 | 4985 | emit_cmp_insn (op1, op2, EQ, NULL_RTX, mode, unsignedp, 0); |
28d81abb RK |
4986 | emit_jump_insn (gen_beq (label)); |
4987 | } | |
4988 | } | |
4989 | \f | |
4990 | /* Not all case values are encountered equally. This function | |
4991 | uses a heuristic to weight case labels, in cases where that | |
4992 | looks like a reasonable thing to do. | |
4993 | ||
4994 | Right now, all we try to guess is text, and we establish the | |
4995 | following weights: | |
4996 | ||
4997 | chars above space: 16 | |
4998 | digits: 16 | |
4999 | default: 12 | |
5000 | space, punct: 8 | |
5001 | tab: 4 | |
5002 | newline: 2 | |
5003 | other "\" chars: 1 | |
5004 | remaining chars: 0 | |
5005 | ||
5006 | If we find any cases in the switch that are not either -1 or in the range | |
5007 | of valid ASCII characters, or are control characters other than those | |
5008 | commonly used with "\", don't treat this switch scanning text. | |
5009 | ||
5010 | Return 1 if these nodes are suitable for cost estimation, otherwise | |
5011 | return 0. */ | |
5012 | ||
5013 | static int | |
5014 | estimate_case_costs (node) | |
5015 | case_node_ptr node; | |
5016 | { | |
5017 | tree min_ascii = build_int_2 (-1, -1); | |
5018 | tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0)); | |
5019 | case_node_ptr n; | |
5020 | int i; | |
5021 | ||
5022 | /* If we haven't already made the cost table, make it now. Note that the | |
5023 | lower bound of the table is -1, not zero. */ | |
5024 | ||
5025 | if (cost_table == NULL) | |
5026 | { | |
5027 | cost_table = ((short *) xmalloc (129 * sizeof (short))) + 1; | |
5028 | bzero (cost_table - 1, 129 * sizeof (short)); | |
5029 | ||
5030 | for (i = 0; i < 128; i++) | |
5031 | { | |
5032 | if (isalnum (i)) | |
5033 | cost_table[i] = 16; | |
5034 | else if (ispunct (i)) | |
5035 | cost_table[i] = 8; | |
5036 | else if (iscntrl (i)) | |
5037 | cost_table[i] = -1; | |
5038 | } | |
5039 | ||
5040 | cost_table[' '] = 8; | |
5041 | cost_table['\t'] = 4; | |
5042 | cost_table['\0'] = 4; | |
5043 | cost_table['\n'] = 2; | |
5044 | cost_table['\f'] = 1; | |
5045 | cost_table['\v'] = 1; | |
5046 | cost_table['\b'] = 1; | |
5047 | } | |
5048 | ||
5049 | /* See if all the case expressions look like text. It is text if the | |
5050 | constant is >= -1 and the highest constant is <= 127. Do all comparisons | |
5051 | as signed arithmetic since we don't want to ever access cost_table with a | |
5052 | value less than -1. Also check that none of the constants in a range | |
5053 | are strange control characters. */ | |
5054 | ||
5055 | for (n = node; n; n = n->right) | |
5056 | { | |
5057 | if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high)) | |
5058 | return 0; | |
5059 | ||
5060 | for (i = TREE_INT_CST_LOW (n->low); i <= TREE_INT_CST_LOW (n->high); i++) | |
5061 | if (cost_table[i] < 0) | |
5062 | return 0; | |
5063 | } | |
5064 | ||
5065 | /* All interesting values are within the range of interesting | |
5066 | ASCII characters. */ | |
5067 | return 1; | |
5068 | } | |
5069 | ||
5070 | /* Scan an ordered list of case nodes | |
5071 | combining those with consecutive values or ranges. | |
5072 | ||
5073 | Eg. three separate entries 1: 2: 3: become one entry 1..3: */ | |
5074 | ||
5075 | static void | |
5076 | group_case_nodes (head) | |
5077 | case_node_ptr head; | |
5078 | { | |
5079 | case_node_ptr node = head; | |
5080 | ||
5081 | while (node) | |
5082 | { | |
5083 | rtx lb = next_real_insn (label_rtx (node->code_label)); | |
5084 | case_node_ptr np = node; | |
5085 | ||
5086 | /* Try to group the successors of NODE with NODE. */ | |
5087 | while (((np = np->right) != 0) | |
5088 | /* Do they jump to the same place? */ | |
5089 | && next_real_insn (label_rtx (np->code_label)) == lb | |
5090 | /* Are their ranges consecutive? */ | |
5091 | && tree_int_cst_equal (np->low, | |
5092 | fold (build (PLUS_EXPR, | |
5093 | TREE_TYPE (node->high), | |
5094 | node->high, | |
5095 | integer_one_node))) | |
5096 | /* An overflow is not consecutive. */ | |
5097 | && tree_int_cst_lt (node->high, | |
5098 | fold (build (PLUS_EXPR, | |
5099 | TREE_TYPE (node->high), | |
5100 | node->high, | |
5101 | integer_one_node)))) | |
5102 | { | |
5103 | node->high = np->high; | |
5104 | } | |
5105 | /* NP is the first node after NODE which can't be grouped with it. | |
5106 | Delete the nodes in between, and move on to that node. */ | |
5107 | node->right = np; | |
5108 | node = np; | |
5109 | } | |
5110 | } | |
5111 | ||
5112 | /* Take an ordered list of case nodes | |
5113 | and transform them into a near optimal binary tree, | |
6dc42e49 | 5114 | on the assumption that any target code selection value is as |
28d81abb RK |
5115 | likely as any other. |
5116 | ||
5117 | The transformation is performed by splitting the ordered | |
5118 | list into two equal sections plus a pivot. The parts are | |
5119 | then attached to the pivot as left and right branches. Each | |
5120 | branch is is then transformed recursively. */ | |
5121 | ||
5122 | static void | |
5123 | balance_case_nodes (head, parent) | |
5124 | case_node_ptr *head; | |
5125 | case_node_ptr parent; | |
5126 | { | |
5127 | register case_node_ptr np; | |
5128 | ||
5129 | np = *head; | |
5130 | if (np) | |
5131 | { | |
5132 | int cost = 0; | |
5133 | int i = 0; | |
5134 | int ranges = 0; | |
5135 | register case_node_ptr *npp; | |
5136 | case_node_ptr left; | |
5137 | ||
5138 | /* Count the number of entries on branch. Also count the ranges. */ | |
5139 | ||
5140 | while (np) | |
5141 | { | |
5142 | if (!tree_int_cst_equal (np->low, np->high)) | |
5143 | { | |
5144 | ranges++; | |
5145 | if (use_cost_table) | |
5146 | cost += cost_table[TREE_INT_CST_LOW (np->high)]; | |
5147 | } | |
5148 | ||
5149 | if (use_cost_table) | |
5150 | cost += cost_table[TREE_INT_CST_LOW (np->low)]; | |
5151 | ||
5152 | i++; | |
5153 | np = np->right; | |
5154 | } | |
5155 | ||
5156 | if (i > 2) | |
5157 | { | |
5158 | /* Split this list if it is long enough for that to help. */ | |
5159 | npp = head; | |
5160 | left = *npp; | |
5161 | if (use_cost_table) | |
5162 | { | |
5163 | /* Find the place in the list that bisects the list's total cost, | |
5164 | Here I gets half the total cost. */ | |
5165 | int n_moved = 0; | |
5166 | i = (cost + 1) / 2; | |
5167 | while (1) | |
5168 | { | |
5169 | /* Skip nodes while their cost does not reach that amount. */ | |
5170 | if (!tree_int_cst_equal ((*npp)->low, (*npp)->high)) | |
5171 | i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)]; | |
5172 | i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)]; | |
5173 | if (i <= 0) | |
5174 | break; | |
5175 | npp = &(*npp)->right; | |
5176 | n_moved += 1; | |
5177 | } | |
5178 | if (n_moved == 0) | |
5179 | { | |
5180 | /* Leave this branch lopsided, but optimize left-hand | |
5181 | side and fill in `parent' fields for right-hand side. */ | |
5182 | np = *head; | |
5183 | np->parent = parent; | |
5184 | balance_case_nodes (&np->left, np); | |
5185 | for (; np->right; np = np->right) | |
5186 | np->right->parent = np; | |
5187 | return; | |
5188 | } | |
5189 | } | |
5190 | /* If there are just three nodes, split at the middle one. */ | |
5191 | else if (i == 3) | |
5192 | npp = &(*npp)->right; | |
5193 | else | |
5194 | { | |
5195 | /* Find the place in the list that bisects the list's total cost, | |
5196 | where ranges count as 2. | |
5197 | Here I gets half the total cost. */ | |
5198 | i = (i + ranges + 1) / 2; | |
5199 | while (1) | |
5200 | { | |
5201 | /* Skip nodes while their cost does not reach that amount. */ | |
5202 | if (!tree_int_cst_equal ((*npp)->low, (*npp)->high)) | |
5203 | i--; | |
5204 | i--; | |
5205 | if (i <= 0) | |
5206 | break; | |
5207 | npp = &(*npp)->right; | |
5208 | } | |
5209 | } | |
5210 | *head = np = *npp; | |
5211 | *npp = 0; | |
5212 | np->parent = parent; | |
5213 | np->left = left; | |
5214 | ||
5215 | /* Optimize each of the two split parts. */ | |
5216 | balance_case_nodes (&np->left, np); | |
5217 | balance_case_nodes (&np->right, np); | |
5218 | } | |
5219 | else | |
5220 | { | |
5221 | /* Else leave this branch as one level, | |
5222 | but fill in `parent' fields. */ | |
5223 | np = *head; | |
5224 | np->parent = parent; | |
5225 | for (; np->right; np = np->right) | |
5226 | np->right->parent = np; | |
5227 | } | |
5228 | } | |
5229 | } | |
5230 | \f | |
5231 | /* Search the parent sections of the case node tree | |
5232 | to see if a test for the lower bound of NODE would be redundant. | |
5233 | INDEX_TYPE is the type of the index expression. | |
5234 | ||
5235 | The instructions to generate the case decision tree are | |
5236 | output in the same order as nodes are processed so it is | |
5237 | known that if a parent node checks the range of the current | |
5238 | node minus one that the current node is bounded at its lower | |
5239 | span. Thus the test would be redundant. */ | |
5240 | ||
5241 | static int | |
5242 | node_has_low_bound (node, index_type) | |
5243 | case_node_ptr node; | |
5244 | tree index_type; | |
5245 | { | |
5246 | tree low_minus_one; | |
5247 | case_node_ptr pnode; | |
5248 | ||
5249 | /* If the lower bound of this node is the lowest value in the index type, | |
5250 | we need not test it. */ | |
5251 | ||
5252 | if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type))) | |
5253 | return 1; | |
5254 | ||
5255 | /* If this node has a left branch, the value at the left must be less | |
5256 | than that at this node, so it cannot be bounded at the bottom and | |
5257 | we need not bother testing any further. */ | |
5258 | ||
5259 | if (node->left) | |
5260 | return 0; | |
5261 | ||
5262 | low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low), | |
5263 | node->low, integer_one_node)); | |
5264 | ||
5265 | /* If the subtraction above overflowed, we can't verify anything. | |
5266 | Otherwise, look for a parent that tests our value - 1. */ | |
5267 | ||
5268 | if (! tree_int_cst_lt (low_minus_one, node->low)) | |
5269 | return 0; | |
5270 | ||
5271 | for (pnode = node->parent; pnode; pnode = pnode->parent) | |
5272 | if (tree_int_cst_equal (low_minus_one, pnode->high)) | |
5273 | return 1; | |
5274 | ||
5275 | return 0; | |
5276 | } | |
5277 | ||
5278 | /* Search the parent sections of the case node tree | |
5279 | to see if a test for the upper bound of NODE would be redundant. | |
5280 | INDEX_TYPE is the type of the index expression. | |
5281 | ||
5282 | The instructions to generate the case decision tree are | |
5283 | output in the same order as nodes are processed so it is | |
5284 | known that if a parent node checks the range of the current | |
5285 | node plus one that the current node is bounded at its upper | |
5286 | span. Thus the test would be redundant. */ | |
5287 | ||
5288 | static int | |
5289 | node_has_high_bound (node, index_type) | |
5290 | case_node_ptr node; | |
5291 | tree index_type; | |
5292 | { | |
5293 | tree high_plus_one; | |
5294 | case_node_ptr pnode; | |
5295 | ||
5296 | /* If the upper bound of this node is the highest value in the type | |
5297 | of the index expression, we need not test against it. */ | |
5298 | ||
5299 | if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type))) | |
5300 | return 1; | |
5301 | ||
5302 | /* If this node has a right branch, the value at the right must be greater | |
5303 | than that at this node, so it cannot be bounded at the top and | |
5304 | we need not bother testing any further. */ | |
5305 | ||
5306 | if (node->right) | |
5307 | return 0; | |
5308 | ||
5309 | high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high), | |
5310 | node->high, integer_one_node)); | |
5311 | ||
5312 | /* If the addition above overflowed, we can't verify anything. | |
5313 | Otherwise, look for a parent that tests our value + 1. */ | |
5314 | ||
5315 | if (! tree_int_cst_lt (node->high, high_plus_one)) | |
5316 | return 0; | |
5317 | ||
5318 | for (pnode = node->parent; pnode; pnode = pnode->parent) | |
5319 | if (tree_int_cst_equal (high_plus_one, pnode->low)) | |
5320 | return 1; | |
5321 | ||
5322 | return 0; | |
5323 | } | |
5324 | ||
5325 | /* Search the parent sections of the | |
5326 | case node tree to see if both tests for the upper and lower | |
5327 | bounds of NODE would be redundant. */ | |
5328 | ||
5329 | static int | |
5330 | node_is_bounded (node, index_type) | |
5331 | case_node_ptr node; | |
5332 | tree index_type; | |
5333 | { | |
5334 | return (node_has_low_bound (node, index_type) | |
5335 | && node_has_high_bound (node, index_type)); | |
5336 | } | |
5337 | ||
5338 | /* Emit an unconditional jump to LABEL unless it would be dead code. */ | |
5339 | ||
5340 | static void | |
5341 | emit_jump_if_reachable (label) | |
5342 | rtx label; | |
5343 | { | |
5344 | if (GET_CODE (get_last_insn ()) != BARRIER) | |
5345 | emit_jump (label); | |
5346 | } | |
5347 | \f | |
5348 | /* Emit step-by-step code to select a case for the value of INDEX. | |
5349 | The thus generated decision tree follows the form of the | |
5350 | case-node binary tree NODE, whose nodes represent test conditions. | |
5351 | INDEX_TYPE is the type of the index of the switch. | |
5352 | ||
5353 | Care is taken to prune redundant tests from the decision tree | |
5354 | by detecting any boundary conditions already checked by | |
5355 | emitted rtx. (See node_has_high_bound, node_has_low_bound | |
5356 | and node_is_bounded, above.) | |
5357 | ||
5358 | Where the test conditions can be shown to be redundant we emit | |
5359 | an unconditional jump to the target code. As a further | |
5360 | optimization, the subordinates of a tree node are examined to | |
5361 | check for bounded nodes. In this case conditional and/or | |
5362 | unconditional jumps as a result of the boundary check for the | |
5363 | current node are arranged to target the subordinates associated | |
5364 | code for out of bound conditions on the current node node. | |
5365 | ||
f72aed24 | 5366 | We can assume that when control reaches the code generated here, |
28d81abb RK |
5367 | the index value has already been compared with the parents |
5368 | of this node, and determined to be on the same side of each parent | |
5369 | as this node is. Thus, if this node tests for the value 51, | |
5370 | and a parent tested for 52, we don't need to consider | |
5371 | the possibility of a value greater than 51. If another parent | |
5372 | tests for the value 50, then this node need not test anything. */ | |
5373 | ||
5374 | static void | |
5375 | emit_case_nodes (index, node, default_label, index_type) | |
5376 | rtx index; | |
5377 | case_node_ptr node; | |
5378 | rtx default_label; | |
5379 | tree index_type; | |
5380 | { | |
5381 | /* If INDEX has an unsigned type, we must make unsigned branches. */ | |
5382 | int unsignedp = TREE_UNSIGNED (index_type); | |
5383 | typedef rtx rtx_function (); | |
5384 | rtx_function *gen_bgt_pat = unsignedp ? gen_bgtu : gen_bgt; | |
5385 | rtx_function *gen_bge_pat = unsignedp ? gen_bgeu : gen_bge; | |
5386 | rtx_function *gen_blt_pat = unsignedp ? gen_bltu : gen_blt; | |
5387 | rtx_function *gen_ble_pat = unsignedp ? gen_bleu : gen_ble; | |
5388 | enum machine_mode mode = GET_MODE (index); | |
5389 | ||
5390 | /* See if our parents have already tested everything for us. | |
5391 | If they have, emit an unconditional jump for this node. */ | |
5392 | if (node_is_bounded (node, index_type)) | |
5393 | emit_jump (label_rtx (node->code_label)); | |
5394 | ||
5395 | else if (tree_int_cst_equal (node->low, node->high)) | |
5396 | { | |
5397 | /* Node is single valued. First see if the index expression matches | |
5398 | this node and then check our children, if any. */ | |
5399 | ||
37366632 | 5400 | do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0), |
28d81abb RK |
5401 | label_rtx (node->code_label), unsignedp); |
5402 | ||
5403 | if (node->right != 0 && node->left != 0) | |
5404 | { | |
5405 | /* This node has children on both sides. | |
5406 | Dispatch to one side or the other | |
5407 | by comparing the index value with this node's value. | |
5408 | If one subtree is bounded, check that one first, | |
5409 | so we can avoid real branches in the tree. */ | |
5410 | ||
5411 | if (node_is_bounded (node->right, index_type)) | |
5412 | { | |
37366632 RK |
5413 | emit_cmp_insn (index, expand_expr (node->high, NULL_RTX, |
5414 | VOIDmode, 0), | |
5415 | GT, NULL_RTX, mode, unsignedp, 0); | |
28d81abb RK |
5416 | |
5417 | emit_jump_insn ((*gen_bgt_pat) (label_rtx (node->right->code_label))); | |
5418 | emit_case_nodes (index, node->left, default_label, index_type); | |
5419 | } | |
5420 | ||
5421 | else if (node_is_bounded (node->left, index_type)) | |
5422 | { | |
37366632 | 5423 | emit_cmp_insn (index, expand_expr (node->high, NULL_RTX, |
28d81abb | 5424 | VOIDmode, 0), |
37366632 | 5425 | LT, NULL_RTX, mode, unsignedp, 0); |
28d81abb RK |
5426 | emit_jump_insn ((*gen_blt_pat) (label_rtx (node->left->code_label))); |
5427 | emit_case_nodes (index, node->right, default_label, index_type); | |
5428 | } | |
5429 | ||
5430 | else | |
5431 | { | |
5432 | /* Neither node is bounded. First distinguish the two sides; | |
5433 | then emit the code for one side at a time. */ | |
5434 | ||
5435 | tree test_label | |
5436 | = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE); | |
5437 | ||
5438 | /* See if the value is on the right. */ | |
37366632 | 5439 | emit_cmp_insn (index, expand_expr (node->high, NULL_RTX, |
28d81abb | 5440 | VOIDmode, 0), |
37366632 | 5441 | GT, NULL_RTX, mode, unsignedp, 0); |
28d81abb RK |
5442 | emit_jump_insn ((*gen_bgt_pat) (label_rtx (test_label))); |
5443 | ||
5444 | /* Value must be on the left. | |
5445 | Handle the left-hand subtree. */ | |
5446 | emit_case_nodes (index, node->left, default_label, index_type); | |
5447 | /* If left-hand subtree does nothing, | |
5448 | go to default. */ | |
5449 | emit_jump_if_reachable (default_label); | |
5450 | ||
5451 | /* Code branches here for the right-hand subtree. */ | |
5452 | expand_label (test_label); | |
5453 | emit_case_nodes (index, node->right, default_label, index_type); | |
5454 | } | |
5455 | } | |
5456 | ||
5457 | else if (node->right != 0 && node->left == 0) | |
5458 | { | |
5459 | /* Here we have a right child but no left so we issue conditional | |
5460 | branch to default and process the right child. | |
5461 | ||
5462 | Omit the conditional branch to default if we it avoid only one | |
5463 | right child; it costs too much space to save so little time. */ | |
5464 | ||
de14fd73 | 5465 | if (node->right->right || node->right->left |
28d81abb RK |
5466 | || !tree_int_cst_equal (node->right->low, node->right->high)) |
5467 | { | |
5468 | if (!node_has_low_bound (node, index_type)) | |
5469 | { | |
37366632 RK |
5470 | emit_cmp_insn (index, expand_expr (node->high, NULL_RTX, |
5471 | VOIDmode, 0), | |
5472 | LT, NULL_RTX, mode, unsignedp, 0); | |
28d81abb RK |
5473 | emit_jump_insn ((*gen_blt_pat) (default_label)); |
5474 | } | |
5475 | ||
5476 | emit_case_nodes (index, node->right, default_label, index_type); | |
5477 | } | |
5478 | else | |
5479 | /* We cannot process node->right normally | |
5480 | since we haven't ruled out the numbers less than | |
5481 | this node's value. So handle node->right explicitly. */ | |
5482 | do_jump_if_equal (index, | |
37366632 RK |
5483 | expand_expr (node->right->low, NULL_RTX, |
5484 | VOIDmode, 0), | |
28d81abb RK |
5485 | label_rtx (node->right->code_label), unsignedp); |
5486 | } | |
5487 | ||
5488 | else if (node->right == 0 && node->left != 0) | |
5489 | { | |
5490 | /* Just one subtree, on the left. */ | |
5491 | ||
de14fd73 RK |
5492 | #if 0 /* The following code and comment were formerly part |
5493 | of the condition here, but they didn't work | |
5494 | and I don't understand what the idea was. -- rms. */ | |
5495 | /* If our "most probable entry" is less probable | |
28d81abb RK |
5496 | than the default label, emit a jump to |
5497 | the default label using condition codes | |
5498 | already lying around. With no right branch, | |
5499 | a branch-greater-than will get us to the default | |
5500 | label correctly. */ | |
de14fd73 RK |
5501 | if (use_cost_table |
5502 | && cost_table[TREE_INT_CST_LOW (node->high)] < 12) | |
5503 | ; | |
5504 | #endif /* 0 */ | |
5505 | if (node->left->left || node->left->right | |
28d81abb RK |
5506 | || !tree_int_cst_equal (node->left->low, node->left->high)) |
5507 | { | |
5508 | if (!node_has_high_bound (node, index_type)) | |
5509 | { | |
37366632 RK |
5510 | emit_cmp_insn (index, expand_expr (node->high, NULL_RTX, |
5511 | VOIDmode, 0), | |
5512 | GT, NULL_RTX, mode, unsignedp, 0); | |
28d81abb RK |
5513 | emit_jump_insn ((*gen_bgt_pat) (default_label)); |
5514 | } | |
5515 | ||
5516 | emit_case_nodes (index, node->left, default_label, index_type); | |
5517 | } | |
5518 | else | |
5519 | /* We cannot process node->left normally | |
5520 | since we haven't ruled out the numbers less than | |
5521 | this node's value. So handle node->left explicitly. */ | |
5522 | do_jump_if_equal (index, | |
37366632 RK |
5523 | expand_expr (node->left->low, NULL_RTX, |
5524 | VOIDmode, 0), | |
28d81abb RK |
5525 | label_rtx (node->left->code_label), unsignedp); |
5526 | } | |
5527 | } | |
5528 | else | |
5529 | { | |
5530 | /* Node is a range. These cases are very similar to those for a single | |
5531 | value, except that we do not start by testing whether this node | |
5532 | is the one to branch to. */ | |
5533 | ||
5534 | if (node->right != 0 && node->left != 0) | |
5535 | { | |
5536 | /* Node has subtrees on both sides. | |
5537 | If the right-hand subtree is bounded, | |
5538 | test for it first, since we can go straight there. | |
5539 | Otherwise, we need to make a branch in the control structure, | |
5540 | then handle the two subtrees. */ | |
5541 | tree test_label = 0; | |
5542 | ||
37366632 RK |
5543 | emit_cmp_insn (index, expand_expr (node->high, NULL_RTX, |
5544 | VOIDmode, 0), | |
5545 | GT, NULL_RTX, mode, unsignedp, 0); | |
28d81abb RK |
5546 | |
5547 | if (node_is_bounded (node->right, index_type)) | |
5548 | /* Right hand node is fully bounded so we can eliminate any | |
5549 | testing and branch directly to the target code. */ | |
5550 | emit_jump_insn ((*gen_bgt_pat) (label_rtx (node->right->code_label))); | |
5551 | else | |
5552 | { | |
5553 | /* Right hand node requires testing. | |
5554 | Branch to a label where we will handle it later. */ | |
5555 | ||
5556 | test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE); | |
5557 | emit_jump_insn ((*gen_bgt_pat) (label_rtx (test_label))); | |
5558 | } | |
5559 | ||
5560 | /* Value belongs to this node or to the left-hand subtree. */ | |
5561 | ||
37366632 RK |
5562 | emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0), |
5563 | GE, NULL_RTX, mode, unsignedp, 0); | |
28d81abb RK |
5564 | emit_jump_insn ((*gen_bge_pat) (label_rtx (node->code_label))); |
5565 | ||
5566 | /* Handle the left-hand subtree. */ | |
5567 | emit_case_nodes (index, node->left, default_label, index_type); | |
5568 | ||
5569 | /* If right node had to be handled later, do that now. */ | |
5570 | ||
5571 | if (test_label) | |
5572 | { | |
5573 | /* If the left-hand subtree fell through, | |
5574 | don't let it fall into the right-hand subtree. */ | |
5575 | emit_jump_if_reachable (default_label); | |
5576 | ||
5577 | expand_label (test_label); | |
5578 | emit_case_nodes (index, node->right, default_label, index_type); | |
5579 | } | |
5580 | } | |
5581 | ||
5582 | else if (node->right != 0 && node->left == 0) | |
5583 | { | |
5584 | /* Deal with values to the left of this node, | |
5585 | if they are possible. */ | |
5586 | if (!node_has_low_bound (node, index_type)) | |
5587 | { | |
37366632 RK |
5588 | emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, |
5589 | VOIDmode, 0), | |
5590 | LT, NULL_RTX, mode, unsignedp, 0); | |
28d81abb RK |
5591 | emit_jump_insn ((*gen_blt_pat) (default_label)); |
5592 | } | |
5593 | ||
5594 | /* Value belongs to this node or to the right-hand subtree. */ | |
5595 | ||
37366632 RK |
5596 | emit_cmp_insn (index, expand_expr (node->high, NULL_RTX, |
5597 | VOIDmode, 0), | |
5598 | LE, NULL_RTX, mode, unsignedp, 0); | |
28d81abb RK |
5599 | emit_jump_insn ((*gen_ble_pat) (label_rtx (node->code_label))); |
5600 | ||
5601 | emit_case_nodes (index, node->right, default_label, index_type); | |
5602 | } | |
5603 | ||
5604 | else if (node->right == 0 && node->left != 0) | |
5605 | { | |
5606 | /* Deal with values to the right of this node, | |
5607 | if they are possible. */ | |
5608 | if (!node_has_high_bound (node, index_type)) | |
5609 | { | |
37366632 RK |
5610 | emit_cmp_insn (index, expand_expr (node->high, NULL_RTX, |
5611 | VOIDmode, 0), | |
5612 | GT, NULL_RTX, mode, unsignedp, 0); | |
28d81abb RK |
5613 | emit_jump_insn ((*gen_bgt_pat) (default_label)); |
5614 | } | |
5615 | ||
5616 | /* Value belongs to this node or to the left-hand subtree. */ | |
5617 | ||
37366632 RK |
5618 | emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0), |
5619 | GE, NULL_RTX, mode, unsignedp, 0); | |
28d81abb RK |
5620 | emit_jump_insn ((*gen_bge_pat) (label_rtx (node->code_label))); |
5621 | ||
5622 | emit_case_nodes (index, node->left, default_label, index_type); | |
5623 | } | |
5624 | ||
5625 | else | |
5626 | { | |
5627 | /* Node has no children so we check low and high bounds to remove | |
5628 | redundant tests. Only one of the bounds can exist, | |
5629 | since otherwise this node is bounded--a case tested already. */ | |
5630 | ||
5631 | if (!node_has_high_bound (node, index_type)) | |
5632 | { | |
37366632 RK |
5633 | emit_cmp_insn (index, expand_expr (node->high, NULL_RTX, |
5634 | VOIDmode, 0), | |
5635 | GT, NULL_RTX, mode, unsignedp, 0); | |
28d81abb RK |
5636 | emit_jump_insn ((*gen_bgt_pat) (default_label)); |
5637 | } | |
5638 | ||
5639 | if (!node_has_low_bound (node, index_type)) | |
5640 | { | |
37366632 RK |
5641 | emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, |
5642 | VOIDmode, 0), | |
5643 | LT, NULL_RTX, mode, unsignedp, 0); | |
28d81abb RK |
5644 | emit_jump_insn ((*gen_blt_pat) (default_label)); |
5645 | } | |
5646 | ||
5647 | emit_jump (label_rtx (node->code_label)); | |
5648 | } | |
5649 | } | |
5650 | } | |
5651 | \f | |
5652 | /* These routines are used by the loop unrolling code. They copy BLOCK trees | |
5653 | so that the debugging info will be correct for the unrolled loop. */ | |
5654 | ||
94dc8b56 | 5655 | /* Indexed by block number, contains a pointer to the N'th block node. */ |
28d81abb | 5656 | |
94dc8b56 | 5657 | static tree *block_vector; |
28d81abb RK |
5658 | |
5659 | void | |
94dc8b56 | 5660 | find_loop_tree_blocks () |
28d81abb | 5661 | { |
94dc8b56 | 5662 | tree block = DECL_INITIAL (current_function_decl); |
28d81abb | 5663 | |
94dc8b56 JW |
5664 | /* There first block is for the function body, and does not have |
5665 | corresponding block notes. Don't include it in the block vector. */ | |
5666 | block = BLOCK_SUBBLOCKS (block); | |
28d81abb | 5667 | |
94dc8b56 | 5668 | block_vector = identify_blocks (block, get_insns ()); |
28d81abb RK |
5669 | } |
5670 | ||
28d81abb | 5671 | void |
94dc8b56 | 5672 | unroll_block_trees () |
28d81abb | 5673 | { |
94dc8b56 | 5674 | tree block = DECL_INITIAL (current_function_decl); |
28d81abb | 5675 | |
94dc8b56 | 5676 | reorder_blocks (block_vector, block, get_insns ()); |
28d81abb | 5677 | } |
94dc8b56 | 5678 |