1 /* Expands front end tree to back end RTL for GNU C-Compiler
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
22 /* This file handles the generation of rtl code from tree structure
23 above the level of expressions, using subroutines in exp*.c and emit-rtl.c.
24 It also creates the rtl expressions for parameters and auto variables
25 and has full responsibility for allocating stack slots.
27 The functions whose names start with `expand_' are called by the
28 parser to generate RTL instructions for various kinds of constructs.
30 Some control and binding constructs require calling several such
31 functions at different times. For example, a simple if-then
32 is expanded by calling `expand_start_cond' (with the condition-expression
33 as argument) before parsing the then-clause and calling `expand_end_cond'
34 after parsing the then-clause. */
45 #include "insn-config.h"
48 #include "hard-reg-set.h"
56 #include "langhooks.h"
58 #define obstack_chunk_alloc xmalloc
59 #define obstack_chunk_free free
60 struct obstack stmt_obstack;
62 /* Assume that case vectors are not pc-relative. */
63 #ifndef CASE_VECTOR_PC_RELATIVE
64 #define CASE_VECTOR_PC_RELATIVE 0
67 /* Functions and data structures for expanding case statements. */
69 /* Case label structure, used to hold info on labels within case
70 statements. We handle "range" labels; for a single-value label
71 as in C, the high and low limits are the same.
73 An AVL tree of case nodes is initially created, and later transformed
74 to a list linked via the RIGHT fields in the nodes. Nodes with
75 higher case values are later in the list.
77 Switch statements can be output in one of two forms. A branch table
78 is used if there are more than a few labels and the labels are dense
79 within the range between the smallest and largest case value. If a
80 branch table is used, no further manipulations are done with the case
83 The alternative to the use of a branch table is to generate a series
84 of compare and jump insns. When that is done, we use the LEFT, RIGHT,
85 and PARENT fields to hold a binary tree. Initially the tree is
86 totally unbalanced, with everything on the right. We balance the tree
87 with nodes on the left having lower case values than the parent
88 and nodes on the right having higher values. We then output the tree
93 struct case_node *left; /* Left son in binary tree */
94 struct case_node *right; /* Right son in binary tree; also node chain */
95 struct case_node *parent; /* Parent of node in binary tree */
96 tree low; /* Lowest index value for this label */
97 tree high; /* Highest index value for this label */
98 tree code_label; /* Label to jump to when node matches */
102 typedef struct case_node case_node;
103 typedef struct case_node *case_node_ptr;
105 /* These are used by estimate_case_costs and balance_case_nodes. */
107 /* This must be a signed type, and non-ANSI compilers lack signed char. */
108 static short cost_table_[129];
109 static int use_cost_table;
110 static int cost_table_initialized;
112 /* Special care is needed because we allow -1, but TREE_INT_CST_LOW
114 #define COST_TABLE(I) cost_table_[(unsigned HOST_WIDE_INT) ((I) + 1)]
116 /* Stack of control and binding constructs we are currently inside.
118 These constructs begin when you call `expand_start_WHATEVER'
119 and end when you call `expand_end_WHATEVER'. This stack records
120 info about how the construct began that tells the end-function
121 what to do. It also may provide information about the construct
122 to alter the behavior of other constructs within the body.
123 For example, they may affect the behavior of C `break' and `continue'.
125 Each construct gets one `struct nesting' object.
126 All of these objects are chained through the `all' field.
127 `nesting_stack' points to the first object (innermost construct).
128 The position of an entry on `nesting_stack' is in its `depth' field.
130 Each type of construct has its own individual stack.
131 For example, loops have `loop_stack'. Each object points to the
132 next object of the same type through the `next' field.
134 Some constructs are visible to `break' exit-statements and others
135 are not. Which constructs are visible depends on the language.
136 Therefore, the data structure allows each construct to be visible
137 or not, according to the args given when the construct is started.
138 The construct is visible if the `exit_label' field is non-null.
139 In that case, the value should be a CODE_LABEL rtx. */
144 struct nesting *next;
149 /* For conds (if-then and if-then-else statements). */
152 /* Label for the end of the if construct.
153 There is none if EXITFLAG was not set
154 and no `else' has been seen yet. */
156 /* Label for the end of this alternative.
157 This may be the end of the if or the next else/elseif. */
163 /* Label at the top of the loop; place to loop back to. */
165 /* Label at the end of the whole construct. */
167 /* Label before a jump that branches to the end of the whole
168 construct. This is where destructors go if any. */
170 /* Label for `continue' statement to jump to;
171 this is in front of the stepper of the loop. */
174 /* For variable binding contours. */
177 /* Sequence number of this binding contour within the function,
178 in order of entry. */
179 int block_start_count;
180 /* Nonzero => value to restore stack to on exit. */
182 /* The NOTE that starts this contour.
183 Used by expand_goto to check whether the destination
184 is within each contour or not. */
186 /* Innermost containing binding contour that has a stack level. */
187 struct nesting *innermost_stack_block;
188 /* List of cleanups to be run on exit from this contour.
189 This is a list of expressions to be evaluated.
190 The TREE_PURPOSE of each link is the ..._DECL node
191 which the cleanup pertains to. */
193 /* List of cleanup-lists of blocks containing this block,
194 as they were at the locus where this block appears.
195 There is an element for each containing block,
196 ordered innermost containing block first.
197 The tail of this list can be 0,
198 if all remaining elements would be empty lists.
199 The element's TREE_VALUE is the cleanup-list of that block,
200 which may be null. */
202 /* Chain of labels defined inside this binding contour.
203 For contours that have stack levels or cleanups. */
204 struct label_chain *label_chain;
205 /* Number of function calls seen, as of start of this block. */
206 int n_function_calls;
207 /* Nonzero if this is associated with a EH region. */
208 int exception_region;
209 /* The saved target_temp_slot_level from our outer block.
210 We may reset target_temp_slot_level to be the level of
211 this block, if that is done, target_temp_slot_level
212 reverts to the saved target_temp_slot_level at the very
214 int block_target_temp_slot_level;
215 /* True if we are currently emitting insns in an area of
216 output code that is controlled by a conditional
217 expression. This is used by the cleanup handling code to
218 generate conditional cleanup actions. */
219 int conditional_code;
220 /* A place to move the start of the exception region for any
221 of the conditional cleanups, must be at the end or after
222 the start of the last unconditional cleanup, and before any
223 conditional branch points. */
224 rtx last_unconditional_cleanup;
225 /* When in a conditional context, this is the specific
226 cleanup list associated with last_unconditional_cleanup,
227 where we place the conditionalized cleanups. */
230 /* For switch (C) or case (Pascal) statements,
231 and also for dummies (see `expand_start_case_dummy'). */
234 /* The insn after which the case dispatch should finally
235 be emitted. Zero for a dummy. */
237 /* A list of case labels; it is first built as an AVL tree.
238 During expand_end_case, this is converted to a list, and may be
239 rearranged into a nearly balanced binary tree. */
240 struct case_node *case_list;
241 /* Label to jump to if no case matches. */
243 /* The expression to be dispatched on. */
245 /* Type that INDEX_EXPR should be converted to. */
247 /* Name of this kind of statement, for warnings. */
248 const char *printname;
249 /* Used to save no_line_numbers till we see the first case label.
250 We set this to -1 when we see the first case label in this
252 int line_number_status;
257 /* Allocate and return a new `struct nesting'. */
259 #define ALLOC_NESTING() \
260 (struct nesting *) obstack_alloc (&stmt_obstack, sizeof (struct nesting))
262 /* Pop the nesting stack element by element until we pop off
263 the element which is at the top of STACK.
264 Update all the other stacks, popping off elements from them
265 as we pop them from nesting_stack. */
267 #define POPSTACK(STACK) \
268 do { struct nesting *target = STACK; \
269 struct nesting *this; \
270 do { this = nesting_stack; \
271 if (loop_stack == this) \
272 loop_stack = loop_stack->next; \
273 if (cond_stack == this) \
274 cond_stack = cond_stack->next; \
275 if (block_stack == this) \
276 block_stack = block_stack->next; \
277 if (stack_block_stack == this) \
278 stack_block_stack = stack_block_stack->next; \
279 if (case_stack == this) \
280 case_stack = case_stack->next; \
281 nesting_depth = nesting_stack->depth - 1; \
282 nesting_stack = this->all; \
283 obstack_free (&stmt_obstack, this); } \
284 while (this != target); } while (0)
286 /* In some cases it is impossible to generate code for a forward goto
287 until the label definition is seen. This happens when it may be necessary
288 for the goto to reset the stack pointer: we don't yet know how to do that.
289 So expand_goto puts an entry on this fixup list.
290 Each time a binding contour that resets the stack is exited,
292 If the target label has now been defined, we can insert the proper code. */
296 /* Points to following fixup. */
297 struct goto_fixup *next;
298 /* Points to the insn before the jump insn.
299 If more code must be inserted, it goes after this insn. */
301 /* The LABEL_DECL that this jump is jumping to, or 0
302 for break, continue or return. */
304 /* The BLOCK for the place where this goto was found. */
306 /* The CODE_LABEL rtx that this is jumping to. */
308 /* Number of binding contours started in current function
309 before the label reference. */
310 int block_start_count;
311 /* The outermost stack level that should be restored for this jump.
312 Each time a binding contour that resets the stack is exited,
313 if the target label is *not* yet defined, this slot is updated. */
315 /* List of lists of cleanup expressions to be run by this goto.
316 There is one element for each block that this goto is within.
317 The tail of this list can be 0,
318 if all remaining elements would be empty.
319 The TREE_VALUE contains the cleanup list of that block as of the
320 time this goto was seen.
321 The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */
322 tree cleanup_list_list;
325 /* Within any binding contour that must restore a stack level,
326 all labels are recorded with a chain of these structures. */
330 /* Points to following fixup. */
331 struct label_chain *next;
337 /* Chain of all pending binding contours. */
338 struct nesting *x_block_stack;
340 /* If any new stacks are added here, add them to POPSTACKS too. */
342 /* Chain of all pending binding contours that restore stack levels
344 struct nesting *x_stack_block_stack;
346 /* Chain of all pending conditional statements. */
347 struct nesting *x_cond_stack;
349 /* Chain of all pending loops. */
350 struct nesting *x_loop_stack;
352 /* Chain of all pending case or switch statements. */
353 struct nesting *x_case_stack;
355 /* Separate chain including all of the above,
356 chained through the `all' field. */
357 struct nesting *x_nesting_stack;
359 /* Number of entries on nesting_stack now. */
362 /* Number of binding contours started so far in this function. */
363 int x_block_start_count;
365 /* Each time we expand an expression-statement,
366 record the expr's type and its RTL value here. */
367 tree x_last_expr_type;
368 rtx x_last_expr_value;
370 /* Nonzero if within a ({...}) grouping, in which case we must
371 always compute a value for each expr-stmt in case it is the last one. */
372 int x_expr_stmts_for_value;
374 /* Filename and line number of last line-number note,
375 whether we actually emitted it or not. */
376 const char *x_emit_filename;
379 struct goto_fixup *x_goto_fixup_chain;
382 #define block_stack (cfun->stmt->x_block_stack)
383 #define stack_block_stack (cfun->stmt->x_stack_block_stack)
384 #define cond_stack (cfun->stmt->x_cond_stack)
385 #define loop_stack (cfun->stmt->x_loop_stack)
386 #define case_stack (cfun->stmt->x_case_stack)
387 #define nesting_stack (cfun->stmt->x_nesting_stack)
388 #define nesting_depth (cfun->stmt->x_nesting_depth)
389 #define current_block_start_count (cfun->stmt->x_block_start_count)
390 #define last_expr_type (cfun->stmt->x_last_expr_type)
391 #define last_expr_value (cfun->stmt->x_last_expr_value)
392 #define expr_stmts_for_value (cfun->stmt->x_expr_stmts_for_value)
393 #define emit_filename (cfun->stmt->x_emit_filename)
394 #define emit_lineno (cfun->stmt->x_emit_lineno)
395 #define goto_fixup_chain (cfun->stmt->x_goto_fixup_chain)
397 /* Non-zero if we are using EH to handle cleanus. */
398 static int using_eh_for_cleanups_p = 0;
400 static int n_occurrences PARAMS ((int, const char *));
401 static bool parse_input_constraint PARAMS ((const char **, int, int, int,
402 int, const char * const *,
404 static void expand_goto_internal PARAMS ((tree, rtx, rtx));
405 static int expand_fixup PARAMS ((tree, rtx, rtx));
406 static rtx expand_nl_handler_label PARAMS ((rtx, rtx));
407 static void expand_nl_goto_receiver PARAMS ((void));
408 static void expand_nl_goto_receivers PARAMS ((struct nesting *));
409 static void fixup_gotos PARAMS ((struct nesting *, rtx, tree,
411 static bool check_operand_nalternatives PARAMS ((tree, tree));
412 static bool check_unique_operand_names PARAMS ((tree, tree));
413 static tree resolve_operand_names PARAMS ((tree, tree, tree,
415 static char *resolve_operand_name_1 PARAMS ((char *, tree, tree));
416 static void expand_null_return_1 PARAMS ((rtx));
417 static void expand_value_return PARAMS ((rtx));
418 static int tail_recursion_args PARAMS ((tree, tree));
419 static void expand_cleanups PARAMS ((tree, tree, int, int));
420 static void check_seenlabel PARAMS ((void));
421 static void do_jump_if_equal PARAMS ((rtx, rtx, rtx, int));
422 static int estimate_case_costs PARAMS ((case_node_ptr));
423 static void group_case_nodes PARAMS ((case_node_ptr));
424 static void balance_case_nodes PARAMS ((case_node_ptr *,
426 static int node_has_low_bound PARAMS ((case_node_ptr, tree));
427 static int node_has_high_bound PARAMS ((case_node_ptr, tree));
428 static int node_is_bounded PARAMS ((case_node_ptr, tree));
429 static void emit_jump_if_reachable PARAMS ((rtx));
430 static void emit_case_nodes PARAMS ((rtx, case_node_ptr, rtx, tree));
431 static struct case_node *case_tree2list PARAMS ((case_node *, case_node *));
432 static void mark_cond_nesting PARAMS ((struct nesting *));
433 static void mark_loop_nesting PARAMS ((struct nesting *));
434 static void mark_block_nesting PARAMS ((struct nesting *));
435 static void mark_case_nesting PARAMS ((struct nesting *));
436 static void mark_case_node PARAMS ((struct case_node *));
437 static void mark_goto_fixup PARAMS ((struct goto_fixup *));
438 static void free_case_nodes PARAMS ((case_node_ptr));
441 using_eh_for_cleanups ()
443 using_eh_for_cleanups_p = 1;
446 /* Mark N (known to be a cond-nesting) for GC. */
449 mark_cond_nesting (n)
454 ggc_mark_rtx (n->exit_label);
455 ggc_mark_rtx (n->data.cond.endif_label);
456 ggc_mark_rtx (n->data.cond.next_label);
462 /* Mark N (known to be a loop-nesting) for GC. */
465 mark_loop_nesting (n)
471 ggc_mark_rtx (n->exit_label);
472 ggc_mark_rtx (n->data.loop.start_label);
473 ggc_mark_rtx (n->data.loop.end_label);
474 ggc_mark_rtx (n->data.loop.alt_end_label);
475 ggc_mark_rtx (n->data.loop.continue_label);
481 /* Mark N (known to be a block-nesting) for GC. */
484 mark_block_nesting (n)
489 struct label_chain *l;
491 ggc_mark_rtx (n->exit_label);
492 ggc_mark_rtx (n->data.block.stack_level);
493 ggc_mark_rtx (n->data.block.first_insn);
494 ggc_mark_tree (n->data.block.cleanups);
495 ggc_mark_tree (n->data.block.outer_cleanups);
497 for (l = n->data.block.label_chain; l != NULL; l = l->next)
500 ggc_mark_tree (l->label);
503 ggc_mark_rtx (n->data.block.last_unconditional_cleanup);
505 /* ??? cleanup_ptr never points outside the stack, does it? */
511 /* Mark N (known to be a case-nesting) for GC. */
514 mark_case_nesting (n)
519 ggc_mark_rtx (n->exit_label);
520 ggc_mark_rtx (n->data.case_stmt.start);
522 ggc_mark_tree (n->data.case_stmt.default_label);
523 ggc_mark_tree (n->data.case_stmt.index_expr);
524 ggc_mark_tree (n->data.case_stmt.nominal_type);
526 mark_case_node (n->data.case_stmt.case_list);
539 ggc_mark_tree (c->low);
540 ggc_mark_tree (c->high);
541 ggc_mark_tree (c->code_label);
543 mark_case_node (c->right);
544 mark_case_node (c->left);
552 struct goto_fixup *g;
557 ggc_mark_rtx (g->before_jump);
558 ggc_mark_tree (g->target);
559 ggc_mark_tree (g->context);
560 ggc_mark_rtx (g->target_rtl);
561 ggc_mark_rtx (g->stack_level);
562 ggc_mark_tree (g->cleanup_list_list);
568 /* Clear out all parts of the state in F that can safely be discarded
569 after the function has been compiled, to let garbage collection
570 reclaim the memory. */
576 /* We're about to free the function obstack. If we hold pointers to
577 things allocated there, then we'll try to mark them when we do
578 GC. So, we clear them out here explicitly. */
588 struct stmt_status *p;
593 mark_block_nesting (p->x_block_stack);
594 mark_cond_nesting (p->x_cond_stack);
595 mark_loop_nesting (p->x_loop_stack);
596 mark_case_nesting (p->x_case_stack);
598 ggc_mark_tree (p->x_last_expr_type);
599 /* last_epxr_value is only valid if last_expr_type is nonzero. */
600 if (p->x_last_expr_type)
601 ggc_mark_rtx (p->x_last_expr_value);
603 mark_goto_fixup (p->x_goto_fixup_chain);
609 gcc_obstack_init (&stmt_obstack);
613 init_stmt_for_function ()
615 cfun->stmt = (struct stmt_status *) xmalloc (sizeof (struct stmt_status));
617 /* We are not currently within any block, conditional, loop or case. */
619 stack_block_stack = 0;
626 current_block_start_count = 0;
628 /* No gotos have been expanded yet. */
629 goto_fixup_chain = 0;
631 /* We are not processing a ({...}) grouping. */
632 expr_stmts_for_value = 0;
634 last_expr_value = NULL_RTX;
637 /* Return nonzero if anything is pushed on the loop, condition, or case
642 return cond_stack || loop_stack || case_stack;
645 /* Record the current file and line. Called from emit_line_note. */
647 set_file_and_line_for_stmt (file, line)
651 /* If we're outputting an inline function, and we add a line note,
652 there may be no CFUN->STMT information. So, there's no need to
656 emit_filename = file;
661 /* Emit a no-op instruction. */
668 last_insn = get_last_insn ();
670 && (GET_CODE (last_insn) == CODE_LABEL
671 || (GET_CODE (last_insn) == NOTE
672 && prev_real_insn (last_insn) == 0)))
673 emit_insn (gen_nop ());
676 /* Return the rtx-label that corresponds to a LABEL_DECL,
677 creating it if necessary. */
683 if (TREE_CODE (label) != LABEL_DECL)
686 if (!DECL_RTL_SET_P (label))
687 SET_DECL_RTL (label, gen_label_rtx ());
689 return DECL_RTL (label);
693 /* Add an unconditional jump to LABEL as the next sequential instruction. */
699 do_pending_stack_adjust ();
700 emit_jump_insn (gen_jump (label));
704 /* Emit code to jump to the address
705 specified by the pointer expression EXP. */
708 expand_computed_goto (exp)
711 rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0);
713 #ifdef POINTERS_EXTEND_UNSIGNED
714 if (GET_MODE (x) != Pmode)
715 x = convert_memory_address (Pmode, x);
719 do_pending_stack_adjust ();
720 emit_indirect_jump (x);
722 current_function_has_computed_jump = 1;
725 /* Handle goto statements and the labels that they can go to. */
727 /* Specify the location in the RTL code of a label LABEL,
728 which is a LABEL_DECL tree node.
730 This is used for the kind of label that the user can jump to with a
731 goto statement, and for alternatives of a switch or case statement.
732 RTL labels generated for loops and conditionals don't go through here;
733 they are generated directly at the RTL level, by other functions below.
735 Note that this has nothing to do with defining label *names*.
736 Languages vary in how they do that and what that even means. */
742 struct label_chain *p;
744 do_pending_stack_adjust ();
745 emit_label (label_rtx (label));
746 if (DECL_NAME (label))
747 LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));
749 if (stack_block_stack != 0)
751 p = (struct label_chain *) ggc_alloc (sizeof (struct label_chain));
752 p->next = stack_block_stack->data.block.label_chain;
753 stack_block_stack->data.block.label_chain = p;
758 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
759 from nested functions. */
762 declare_nonlocal_label (label)
765 rtx slot = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
767 nonlocal_labels = tree_cons (NULL_TREE, label, nonlocal_labels);
768 LABEL_PRESERVE_P (label_rtx (label)) = 1;
769 if (nonlocal_goto_handler_slots == 0)
771 emit_stack_save (SAVE_NONLOCAL,
772 &nonlocal_goto_stack_level,
773 PREV_INSN (tail_recursion_reentry));
775 nonlocal_goto_handler_slots
776 = gen_rtx_EXPR_LIST (VOIDmode, slot, nonlocal_goto_handler_slots);
779 /* Generate RTL code for a `goto' statement with target label LABEL.
780 LABEL should be a LABEL_DECL tree node that was or will later be
781 defined with `expand_label'. */
789 /* Check for a nonlocal goto to a containing function. */
790 context = decl_function_context (label);
791 if (context != 0 && context != current_function_decl)
793 struct function *p = find_function_data (context);
794 rtx label_ref = gen_rtx_LABEL_REF (Pmode, label_rtx (label));
795 rtx handler_slot, static_chain, save_area, insn;
798 /* Find the corresponding handler slot for this label. */
799 handler_slot = p->x_nonlocal_goto_handler_slots;
800 for (link = p->x_nonlocal_labels; TREE_VALUE (link) != label;
801 link = TREE_CHAIN (link))
802 handler_slot = XEXP (handler_slot, 1);
803 handler_slot = XEXP (handler_slot, 0);
805 p->has_nonlocal_label = 1;
806 current_function_has_nonlocal_goto = 1;
807 LABEL_REF_NONLOCAL_P (label_ref) = 1;
809 /* Copy the rtl for the slots so that they won't be shared in
810 case the virtual stack vars register gets instantiated differently
811 in the parent than in the child. */
813 static_chain = copy_to_reg (lookup_static_chain (label));
815 /* Get addr of containing function's current nonlocal goto handler,
816 which will do any cleanups and then jump to the label. */
817 handler_slot = copy_to_reg (replace_rtx (copy_rtx (handler_slot),
818 virtual_stack_vars_rtx,
821 /* Get addr of containing function's nonlocal save area. */
822 save_area = p->x_nonlocal_goto_stack_level;
824 save_area = replace_rtx (copy_rtx (save_area),
825 virtual_stack_vars_rtx, static_chain);
827 #if HAVE_nonlocal_goto
828 if (HAVE_nonlocal_goto)
829 emit_insn (gen_nonlocal_goto (static_chain, handler_slot,
830 save_area, label_ref));
834 /* Restore frame pointer for containing function.
835 This sets the actual hard register used for the frame pointer
836 to the location of the function's incoming static chain info.
837 The non-local goto handler will then adjust it to contain the
838 proper value and reload the argument pointer, if needed. */
839 emit_move_insn (hard_frame_pointer_rtx, static_chain);
840 emit_stack_restore (SAVE_NONLOCAL, save_area, NULL_RTX);
842 /* USE of hard_frame_pointer_rtx added for consistency;
843 not clear if really needed. */
844 emit_insn (gen_rtx_USE (VOIDmode, hard_frame_pointer_rtx));
845 emit_insn (gen_rtx_USE (VOIDmode, stack_pointer_rtx));
846 emit_indirect_jump (handler_slot);
849 /* Search backwards to the jump insn and mark it as a
851 for (insn = get_last_insn (); insn; insn = PREV_INSN (insn))
853 if (GET_CODE (insn) == JUMP_INSN)
855 REG_NOTES (insn) = alloc_EXPR_LIST (REG_NON_LOCAL_GOTO,
856 const0_rtx, REG_NOTES (insn));
859 else if (GET_CODE (insn) == CALL_INSN)
864 expand_goto_internal (label, label_rtx (label), NULL_RTX);
867 /* Generate RTL code for a `goto' statement with target label BODY.
868 LABEL should be a LABEL_REF.
869 LAST_INSN, if non-0, is the rtx we should consider as the last
870 insn emitted (for the purposes of cleaning up a return). */
873 expand_goto_internal (body, label, last_insn)
878 struct nesting *block;
881 if (GET_CODE (label) != CODE_LABEL)
884 /* If label has already been defined, we can tell now
885 whether and how we must alter the stack level. */
887 if (PREV_INSN (label) != 0)
889 /* Find the innermost pending block that contains the label.
890 (Check containment by comparing insn-uids.)
891 Then restore the outermost stack level within that block,
892 and do cleanups of all blocks contained in it. */
893 for (block = block_stack; block; block = block->next)
895 if (INSN_UID (block->data.block.first_insn) < INSN_UID (label))
897 if (block->data.block.stack_level != 0)
898 stack_level = block->data.block.stack_level;
899 /* Execute the cleanups for blocks we are exiting. */
900 if (block->data.block.cleanups != 0)
902 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1);
903 do_pending_stack_adjust ();
909 /* Ensure stack adjust isn't done by emit_jump, as this
910 would clobber the stack pointer. This one should be
911 deleted as dead by flow. */
912 clear_pending_stack_adjust ();
913 do_pending_stack_adjust ();
915 /* Don't do this adjust if it's to the end label and this function
916 is to return with a depressed stack pointer. */
917 if (label == return_label
918 && (((TREE_CODE (TREE_TYPE (current_function_decl))
920 && (TYPE_RETURNS_STACK_DEPRESSED
921 (TREE_TYPE (current_function_decl))))))
924 emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX);
927 if (body != 0 && DECL_TOO_LATE (body))
928 error ("jump to `%s' invalidly jumps into binding contour",
929 IDENTIFIER_POINTER (DECL_NAME (body)));
931 /* Label not yet defined: may need to put this goto
932 on the fixup list. */
933 else if (! expand_fixup (body, label, last_insn))
935 /* No fixup needed. Record that the label is the target
936 of at least one goto that has no fixup. */
938 TREE_ADDRESSABLE (body) = 1;
944 /* Generate if necessary a fixup for a goto
945 whose target label in tree structure (if any) is TREE_LABEL
946 and whose target in rtl is RTL_LABEL.
948 If LAST_INSN is nonzero, we pretend that the jump appears
949 after insn LAST_INSN instead of at the current point in the insn stream.
951 The fixup will be used later to insert insns just before the goto.
952 Those insns will restore the stack level as appropriate for the
953 target label, and will (in the case of C++) also invoke any object
954 destructors which have to be invoked when we exit the scopes which
955 are exited by the goto.
957 Value is nonzero if a fixup is made. */
960 expand_fixup (tree_label, rtl_label, last_insn)
965 struct nesting *block, *end_block;
967 /* See if we can recognize which block the label will be output in.
968 This is possible in some very common cases.
969 If we succeed, set END_BLOCK to that block.
970 Otherwise, set it to 0. */
973 && (rtl_label == cond_stack->data.cond.endif_label
974 || rtl_label == cond_stack->data.cond.next_label))
975 end_block = cond_stack;
976 /* If we are in a loop, recognize certain labels which
977 are likely targets. This reduces the number of fixups
978 we need to create. */
980 && (rtl_label == loop_stack->data.loop.start_label
981 || rtl_label == loop_stack->data.loop.end_label
982 || rtl_label == loop_stack->data.loop.continue_label))
983 end_block = loop_stack;
987 /* Now set END_BLOCK to the binding level to which we will return. */
991 struct nesting *next_block = end_block->all;
994 /* First see if the END_BLOCK is inside the innermost binding level.
995 If so, then no cleanups or stack levels are relevant. */
996 while (next_block && next_block != block)
997 next_block = next_block->all;
1002 /* Otherwise, set END_BLOCK to the innermost binding level
1003 which is outside the relevant control-structure nesting. */
1004 next_block = block_stack->next;
1005 for (block = block_stack; block != end_block; block = block->all)
1006 if (block == next_block)
1007 next_block = next_block->next;
1008 end_block = next_block;
1011 /* Does any containing block have a stack level or cleanups?
1012 If not, no fixup is needed, and that is the normal case
1013 (the only case, for standard C). */
1014 for (block = block_stack; block != end_block; block = block->next)
1015 if (block->data.block.stack_level != 0
1016 || block->data.block.cleanups != 0)
1019 if (block != end_block)
1021 /* Ok, a fixup is needed. Add a fixup to the list of such. */
1022 struct goto_fixup *fixup
1023 = (struct goto_fixup *) ggc_alloc (sizeof (struct goto_fixup));
1024 /* In case an old stack level is restored, make sure that comes
1025 after any pending stack adjust. */
1026 /* ?? If the fixup isn't to come at the present position,
1027 doing the stack adjust here isn't useful. Doing it with our
1028 settings at that location isn't useful either. Let's hope
1031 do_pending_stack_adjust ();
1032 fixup->target = tree_label;
1033 fixup->target_rtl = rtl_label;
1035 /* Create a BLOCK node and a corresponding matched set of
1036 NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes at
1037 this point. The notes will encapsulate any and all fixup
1038 code which we might later insert at this point in the insn
1039 stream. Also, the BLOCK node will be the parent (i.e. the
1040 `SUPERBLOCK') of any other BLOCK nodes which we might create
1041 later on when we are expanding the fixup code.
1043 Note that optimization passes (including expand_end_loop)
1044 might move the *_BLOCK notes away, so we use a NOTE_INSN_DELETED
1045 as a placeholder. */
1048 rtx original_before_jump
1049 = last_insn ? last_insn : get_last_insn ();
1054 block = make_node (BLOCK);
1055 TREE_USED (block) = 1;
1057 if (!cfun->x_whole_function_mode_p)
1058 (*lang_hooks.decls.insert_block) (block);
1062 = BLOCK_CHAIN (DECL_INITIAL (current_function_decl));
1063 BLOCK_CHAIN (DECL_INITIAL (current_function_decl))
1068 start = emit_note (NULL, NOTE_INSN_BLOCK_BEG);
1069 if (cfun->x_whole_function_mode_p)
1070 NOTE_BLOCK (start) = block;
1071 fixup->before_jump = emit_note (NULL, NOTE_INSN_DELETED);
1072 end = emit_note (NULL, NOTE_INSN_BLOCK_END);
1073 if (cfun->x_whole_function_mode_p)
1074 NOTE_BLOCK (end) = block;
1075 fixup->context = block;
1077 emit_insns_after (start, original_before_jump);
1080 fixup->block_start_count = current_block_start_count;
1081 fixup->stack_level = 0;
1082 fixup->cleanup_list_list
1083 = ((block->data.block.outer_cleanups
1084 || block->data.block.cleanups)
1085 ? tree_cons (NULL_TREE, block->data.block.cleanups,
1086 block->data.block.outer_cleanups)
1088 fixup->next = goto_fixup_chain;
1089 goto_fixup_chain = fixup;
1095 /* Expand any needed fixups in the outputmost binding level of the
1096 function. FIRST_INSN is the first insn in the function. */
1099 expand_fixups (first_insn)
1102 fixup_gotos (NULL, NULL_RTX, NULL_TREE, first_insn, 0);
1105 /* When exiting a binding contour, process all pending gotos requiring fixups.
1106 THISBLOCK is the structure that describes the block being exited.
1107 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1108 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1109 FIRST_INSN is the insn that began this contour.
1111 Gotos that jump out of this contour must restore the
1112 stack level and do the cleanups before actually jumping.
1114 DONT_JUMP_IN nonzero means report error there is a jump into this
1115 contour from before the beginning of the contour.
1116 This is also done if STACK_LEVEL is nonzero. */
1119 fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1120 struct nesting *thisblock;
1126 struct goto_fixup *f, *prev;
1128 /* F is the fixup we are considering; PREV is the previous one. */
1129 /* We run this loop in two passes so that cleanups of exited blocks
1130 are run first, and blocks that are exited are marked so
1133 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1135 /* Test for a fixup that is inactive because it is already handled. */
1136 if (f->before_jump == 0)
1138 /* Delete inactive fixup from the chain, if that is easy to do. */
1140 prev->next = f->next;
1142 /* Has this fixup's target label been defined?
1143 If so, we can finalize it. */
1144 else if (PREV_INSN (f->target_rtl) != 0)
1148 /* If this fixup jumped into this contour from before the beginning
1149 of this contour, report an error. This code used to use
1150 the first non-label insn after f->target_rtl, but that's
1151 wrong since such can be added, by things like put_var_into_stack
1152 and have INSN_UIDs that are out of the range of the block. */
1153 /* ??? Bug: this does not detect jumping in through intermediate
1154 blocks that have stack levels or cleanups.
1155 It detects only a problem with the innermost block
1156 around the label. */
1158 && (dont_jump_in || stack_level || cleanup_list)
1159 && INSN_UID (first_insn) < INSN_UID (f->target_rtl)
1160 && INSN_UID (first_insn) > INSN_UID (f->before_jump)
1161 && ! DECL_ERROR_ISSUED (f->target))
1163 error_with_decl (f->target,
1164 "label `%s' used before containing binding contour");
1165 /* Prevent multiple errors for one label. */
1166 DECL_ERROR_ISSUED (f->target) = 1;
1169 /* We will expand the cleanups into a sequence of their own and
1170 then later on we will attach this new sequence to the insn
1171 stream just ahead of the actual jump insn. */
1175 /* Temporarily restore the lexical context where we will
1176 logically be inserting the fixup code. We do this for the
1177 sake of getting the debugging information right. */
1179 (*lang_hooks.decls.pushlevel) (0);
1180 (*lang_hooks.decls.set_block) (f->context);
1182 /* Expand the cleanups for blocks this jump exits. */
1183 if (f->cleanup_list_list)
1186 for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists))
1187 /* Marked elements correspond to blocks that have been closed.
1188 Do their cleanups. */
1189 if (TREE_ADDRESSABLE (lists)
1190 && TREE_VALUE (lists) != 0)
1192 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1193 /* Pop any pushes done in the cleanups,
1194 in case function is about to return. */
1195 do_pending_stack_adjust ();
1199 /* Restore stack level for the biggest contour that this
1200 jump jumps out of. */
1202 && ! (f->target_rtl == return_label
1203 && ((TREE_CODE (TREE_TYPE (current_function_decl))
1205 && (TYPE_RETURNS_STACK_DEPRESSED
1206 (TREE_TYPE (current_function_decl))))))
1207 emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump);
1209 /* Finish up the sequence containing the insns which implement the
1210 necessary cleanups, and then attach that whole sequence to the
1211 insn stream just ahead of the actual jump insn. Attaching it
1212 at that point insures that any cleanups which are in fact
1213 implicit C++ object destructions (which must be executed upon
1214 leaving the block) appear (to the debugger) to be taking place
1215 in an area of the generated code where the object(s) being
1216 destructed are still "in scope". */
1218 cleanup_insns = get_insns ();
1219 (*lang_hooks.decls.poplevel) (1, 0, 0);
1222 emit_insns_after (cleanup_insns, f->before_jump);
1228 /* For any still-undefined labels, do the cleanups for this block now.
1229 We must do this now since items in the cleanup list may go out
1230 of scope when the block ends. */
1231 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1232 if (f->before_jump != 0
1233 && PREV_INSN (f->target_rtl) == 0
1234 /* Label has still not appeared. If we are exiting a block with
1235 a stack level to restore, that started before the fixup,
1236 mark this stack level as needing restoration
1237 when the fixup is later finalized. */
1239 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1240 means the label is undefined. That's erroneous, but possible. */
1241 && (thisblock->data.block.block_start_count
1242 <= f->block_start_count))
1244 tree lists = f->cleanup_list_list;
1247 for (; lists; lists = TREE_CHAIN (lists))
1248 /* If the following elt. corresponds to our containing block
1249 then the elt. must be for this block. */
1250 if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups)
1253 (*lang_hooks.decls.pushlevel) (0);
1254 (*lang_hooks.decls.set_block) (f->context);
1255 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1256 do_pending_stack_adjust ();
1257 cleanup_insns = get_insns ();
1258 (*lang_hooks.decls.poplevel) (1, 0, 0);
1260 if (cleanup_insns != 0)
1262 = emit_insns_after (cleanup_insns, f->before_jump);
1264 f->cleanup_list_list = TREE_CHAIN (lists);
1268 f->stack_level = stack_level;
1272 /* Return the number of times character C occurs in string S. */
1274 n_occurrences (c, s)
1284 /* Generate RTL for an asm statement (explicit assembler code).
1285 BODY is a STRING_CST node containing the assembler code text,
1286 or an ADDR_EXPR containing a STRING_CST. */
1292 if (TREE_CODE (body) == ADDR_EXPR)
1293 body = TREE_OPERAND (body, 0);
1295 emit_insn (gen_rtx_ASM_INPUT (VOIDmode,
1296 TREE_STRING_POINTER (body)));
1300 /* Parse the output constraint pointed to by *CONSTRAINT_P. It is the
1301 OPERAND_NUMth output operand, indexed from zero. There are NINPUTS
1302 inputs and NOUTPUTS outputs to this extended-asm. Upon return,
1303 *ALLOWS_MEM will be TRUE iff the constraint allows the use of a
1304 memory operand. Similarly, *ALLOWS_REG will be TRUE iff the
1305 constraint allows the use of a register operand. And, *IS_INOUT
1306 will be true if the operand is read-write, i.e., if it is used as
1307 an input as well as an output. If *CONSTRAINT_P is not in
1308 canonical form, it will be made canonical. (Note that `+' will be
1309 rpelaced with `=' as part of this process.)
1311 Returns TRUE if all went well; FALSE if an error occurred. */
1314 parse_output_constraint (constraint_p, operand_num, ninputs, noutputs,
1315 allows_mem, allows_reg, is_inout)
1316 const char **constraint_p;
1324 const char *constraint = *constraint_p;
1327 /* Assume the constraint doesn't allow the use of either a register
1329 *allows_mem = false;
1330 *allows_reg = false;
1332 /* Allow the `=' or `+' to not be at the beginning of the string,
1333 since it wasn't explicitly documented that way, and there is a
1334 large body of code that puts it last. Swap the character to
1335 the front, so as not to uglify any place else. */
1336 p = strchr (constraint, '=');
1338 p = strchr (constraint, '+');
1340 /* If the string doesn't contain an `=', issue an error
1344 error ("output operand constraint lacks `='");
1348 /* If the constraint begins with `+', then the operand is both read
1349 from and written to. */
1350 *is_inout = (*p == '+');
1352 /* Canonicalize the output constraint so that it begins with `='. */
1353 if (p != constraint || is_inout)
1356 size_t c_len = strlen (constraint);
1358 if (p != constraint)
1359 warning ("output constraint `%c' for operand %d is not at the beginning",
1362 /* Make a copy of the constraint. */
1363 buf = alloca (c_len + 1);
1364 strcpy (buf, constraint);
1365 /* Swap the first character and the `=' or `+'. */
1366 buf[p - constraint] = buf[0];
1367 /* Make sure the first character is an `='. (Until we do this,
1368 it might be a `+'.) */
1370 /* Replace the constraint with the canonicalized string. */
1371 *constraint_p = ggc_alloc_string (buf, c_len);
1372 constraint = *constraint_p;
1375 /* Loop through the constraint string. */
1376 for (p = constraint + 1; *p; ++p)
1381 error ("operand constraint contains incorrectly positioned '+' or '='");
1385 if (operand_num + 1 == ninputs + noutputs)
1387 error ("`%%' constraint used with last operand");
1392 case 'V': case 'm': case 'o':
1396 case '?': case '!': case '*': case '&': case '#':
1397 case 'E': case 'F': case 'G': case 'H':
1398 case 's': case 'i': case 'n':
1399 case 'I': case 'J': case 'K': case 'L': case 'M':
1400 case 'N': case 'O': case 'P': case ',':
1403 case '0': case '1': case '2': case '3': case '4':
1404 case '5': case '6': case '7': case '8': case '9':
1406 error ("matching constraint not valid in output operand");
1410 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
1411 excepting those that expand_call created. So match memory
1428 if (REG_CLASS_FROM_LETTER (*p) != NO_REGS)
1430 #ifdef EXTRA_CONSTRAINT
1433 /* Otherwise we can't assume anything about the nature of
1434 the constraint except that it isn't purely registers.
1435 Treat it like "g" and hope for the best. */
1446 /* Similar, but for input constraints. */
1449 parse_input_constraint (constraint_p, input_num, ninputs, noutputs, ninout,
1450 constraints, allows_mem, allows_reg)
1451 const char **constraint_p;
1456 const char * const * constraints;
1460 const char *constraint = *constraint_p;
1461 const char *orig_constraint = constraint;
1462 size_t c_len = strlen (constraint);
1465 /* Assume the constraint doesn't allow the use of either
1466 a register or memory. */
1467 *allows_mem = false;
1468 *allows_reg = false;
1470 /* Make sure constraint has neither `=', `+', nor '&'. */
1472 for (j = 0; j < c_len; j++)
1473 switch (constraint[j])
1475 case '+': case '=': case '&':
1476 if (constraint == orig_constraint)
1478 error ("input operand constraint contains `%c'", constraint[j]);
1484 if (constraint == orig_constraint
1485 && input_num + 1 == ninputs - ninout)
1487 error ("`%%' constraint used with last operand");
1492 case 'V': case 'm': case 'o':
1497 case '?': case '!': case '*': case '#':
1498 case 'E': case 'F': case 'G': case 'H':
1499 case 's': case 'i': case 'n':
1500 case 'I': case 'J': case 'K': case 'L': case 'M':
1501 case 'N': case 'O': case 'P': case ',':
1504 /* Whether or not a numeric constraint allows a register is
1505 decided by the matching constraint, and so there is no need
1506 to do anything special with them. We must handle them in
1507 the default case, so that we don't unnecessarily force
1508 operands to memory. */
1509 case '0': case '1': case '2': case '3': case '4':
1510 case '5': case '6': case '7': case '8': case '9':
1513 unsigned long match;
1515 match = strtoul (constraint + j, &end, 10);
1516 if (match >= (unsigned long) noutputs)
1518 error ("matching constraint references invalid operand number");
1522 /* Try and find the real constraint for this dup. Only do this
1523 if the matching constraint is the only alternative. */
1525 && (j == 0 || (j == 1 && constraint[0] == '%')))
1527 constraint = constraints[match];
1528 *constraint_p = constraint;
1529 c_len = strlen (constraint);
1534 j = end - constraint;
1548 if (! ISALPHA (constraint[j]))
1550 error ("invalid punctuation `%c' in constraint", constraint[j]);
1553 if (REG_CLASS_FROM_LETTER (constraint[j]) != NO_REGS)
1555 #ifdef EXTRA_CONSTRAINT
1558 /* Otherwise we can't assume anything about the nature of
1559 the constraint except that it isn't purely registers.
1560 Treat it like "g" and hope for the best. */
1571 /* Generate RTL for an asm statement with arguments.
1572 STRING is the instruction template.
1573 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1574 Each output or input has an expression in the TREE_VALUE and
1575 and a tree list in TREE_PURPOSE which in turn contains a constraint
1576 name in TREE_VALUE (or NULL_TREE) and a constraint string
1578 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1579 that is clobbered by this insn.
1581 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1582 Some elements of OUTPUTS may be replaced with trees representing temporary
1583 values. The caller should copy those temporary values to the originally
1586 VOL nonzero means the insn is volatile; don't optimize it. */
1589 expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line)
1590 tree string, outputs, inputs, clobbers;
1592 const char *filename;
1595 rtvec argvec, constraintvec;
1597 int ninputs = list_length (inputs);
1598 int noutputs = list_length (outputs);
1603 /* Vector of RTX's of evaluated output operands. */
1604 rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1605 int *inout_opnum = (int *) alloca (noutputs * sizeof (int));
1606 rtx *real_output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1607 enum machine_mode *inout_mode
1608 = (enum machine_mode *) alloca (noutputs * sizeof (enum machine_mode));
1609 const char **constraints
1610 = (const char **) alloca ((noutputs + ninputs) * sizeof (const char *));
1611 /* The insn we have emitted. */
1613 int old_generating_concat_p = generating_concat_p;
1615 /* An ASM with no outputs needs to be treated as volatile, for now. */
1619 if (! check_operand_nalternatives (outputs, inputs))
1622 if (! check_unique_operand_names (outputs, inputs))
1625 string = resolve_operand_names (string, outputs, inputs, constraints);
1627 #ifdef MD_ASM_CLOBBERS
1628 /* Sometimes we wish to automatically clobber registers across an asm.
1629 Case in point is when the i386 backend moved from cc0 to a hard reg --
1630 maintaining source-level compatibility means automatically clobbering
1631 the flags register. */
1632 MD_ASM_CLOBBERS (clobbers);
1635 /* Count the number of meaningful clobbered registers, ignoring what
1636 we would ignore later. */
1638 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1640 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1642 i = decode_reg_name (regname);
1643 if (i >= 0 || i == -4)
1646 error ("unknown register name `%s' in `asm'", regname);
1651 /* First pass over inputs and outputs checks validity and sets
1652 mark_addressable if needed. */
1655 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1657 tree val = TREE_VALUE (tail);
1658 tree type = TREE_TYPE (val);
1659 const char *constraint;
1664 /* If there's an erroneous arg, emit no insn. */
1665 if (type == error_mark_node)
1668 /* Try to parse the output constraint. If that fails, there's
1669 no point in going further. */
1670 constraint = constraints[i];
1671 if (!parse_output_constraint (&constraint, i, ninputs, noutputs,
1672 &allows_mem, &allows_reg, &is_inout))
1679 && GET_CODE (DECL_RTL (val)) == REG
1680 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type))))
1681 mark_addressable (val);
1688 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
1690 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
1694 for (i = 0, tail = inputs; tail; i++, tail = TREE_CHAIN (tail))
1696 bool allows_reg, allows_mem;
1697 const char *constraint;
1699 /* If there's an erroneous arg, emit no insn, because the ASM_INPUT
1700 would get VOIDmode and that could cause a crash in reload. */
1701 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
1704 constraint = constraints[i + noutputs];
1705 if (! parse_input_constraint (&constraint, i, ninputs, noutputs, ninout,
1706 constraints, &allows_mem, &allows_reg))
1709 if (! allows_reg && allows_mem)
1710 mark_addressable (TREE_VALUE (tail));
1713 /* Second pass evaluates arguments. */
1716 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1718 tree val = TREE_VALUE (tail);
1719 tree type = TREE_TYPE (val);
1724 if (!parse_output_constraint (&constraints[i], i, ninputs,
1725 noutputs, &allows_mem, &allows_reg,
1729 /* If an output operand is not a decl or indirect ref and our constraint
1730 allows a register, make a temporary to act as an intermediate.
1731 Make the asm insn write into that, then our caller will copy it to
1732 the real output operand. Likewise for promoted variables. */
1734 generating_concat_p = 0;
1736 real_output_rtx[i] = NULL_RTX;
1737 if ((TREE_CODE (val) == INDIRECT_REF
1740 && (allows_mem || GET_CODE (DECL_RTL (val)) == REG)
1741 && ! (GET_CODE (DECL_RTL (val)) == REG
1742 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
1746 output_rtx[i] = expand_expr (val, NULL_RTX, VOIDmode, EXPAND_WRITE);
1748 if (! allows_reg && GET_CODE (output_rtx[i]) != MEM)
1749 error ("output number %d not directly addressable", i);
1750 if ((! allows_mem && GET_CODE (output_rtx[i]) == MEM)
1751 || GET_CODE (output_rtx[i]) == CONCAT)
1753 real_output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1754 output_rtx[i] = gen_reg_rtx (GET_MODE (output_rtx[i]));
1756 emit_move_insn (output_rtx[i], real_output_rtx[i]);
1761 output_rtx[i] = assign_temp (type, 0, 0, 1);
1762 TREE_VALUE (tail) = make_tree (type, output_rtx[i]);
1765 generating_concat_p = old_generating_concat_p;
1769 inout_mode[ninout] = TYPE_MODE (type);
1770 inout_opnum[ninout++] = i;
1774 /* Make vectors for the expression-rtx, constraint strings,
1775 and named operands. */
1777 argvec = rtvec_alloc (ninputs);
1778 constraintvec = rtvec_alloc (ninputs);
1780 body = gen_rtx_ASM_OPERANDS ((noutputs == 0 ? VOIDmode
1781 : GET_MODE (output_rtx[0])),
1782 TREE_STRING_POINTER (string),
1783 empty_string, 0, argvec, constraintvec,
1786 MEM_VOLATILE_P (body) = vol;
1788 /* Eval the inputs and put them into ARGVEC.
1789 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1791 for (i = 0, tail = inputs; tail; tail = TREE_CHAIN (tail), ++i)
1793 bool allows_reg, allows_mem;
1794 const char *constraint;
1798 constraint = constraints[i + noutputs];
1799 if (! parse_input_constraint (&constraint, i, ninputs, noutputs, ninout,
1800 constraints, &allows_mem, &allows_reg))
1803 generating_concat_p = 0;
1805 val = TREE_VALUE (tail);
1806 type = TREE_TYPE (val);
1807 op = expand_expr (val, NULL_RTX, VOIDmode, 0);
1809 /* Never pass a CONCAT to an ASM. */
1810 if (GET_CODE (op) == CONCAT)
1811 op = force_reg (GET_MODE (op), op);
1813 if (asm_operand_ok (op, constraint) <= 0)
1816 op = force_reg (TYPE_MODE (type), op);
1817 else if (!allows_mem)
1818 warning ("asm operand %d probably doesn't match constraints",
1820 else if (CONSTANT_P (op))
1821 op = force_const_mem (TYPE_MODE (type), op);
1822 else if (GET_CODE (op) == REG
1823 || GET_CODE (op) == SUBREG
1824 || GET_CODE (op) == ADDRESSOF
1825 || GET_CODE (op) == CONCAT)
1827 tree qual_type = build_qualified_type (type,
1829 | TYPE_QUAL_CONST));
1830 rtx memloc = assign_temp (qual_type, 1, 1, 1);
1832 emit_move_insn (memloc, op);
1836 else if (GET_CODE (op) == MEM && MEM_VOLATILE_P (op))
1838 /* We won't recognize volatile memory as available a
1839 memory_operand at this point. Ignore it. */
1841 else if (queued_subexp_p (op))
1844 /* ??? Leave this only until we have experience with what
1845 happens in combine and elsewhere when constraints are
1847 warning ("asm operand %d probably doesn't match constraints",
1851 generating_concat_p = old_generating_concat_p;
1852 ASM_OPERANDS_INPUT (body, i) = op;
1854 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body, i)
1855 = gen_rtx_ASM_INPUT (TYPE_MODE (type), constraints[i + noutputs]);
1858 /* Protect all the operands from the queue now that they have all been
1861 generating_concat_p = 0;
1863 for (i = 0; i < ninputs - ninout; i++)
1864 ASM_OPERANDS_INPUT (body, i)
1865 = protect_from_queue (ASM_OPERANDS_INPUT (body, i), 0);
1867 for (i = 0; i < noutputs; i++)
1868 output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1870 /* For in-out operands, copy output rtx to input rtx. */
1871 for (i = 0; i < ninout; i++)
1873 int j = inout_opnum[i];
1876 ASM_OPERANDS_INPUT (body, ninputs - ninout + i)
1879 sprintf (buffer, "%d", j);
1880 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body, ninputs - ninout + i)
1881 = gen_rtx_ASM_INPUT (inout_mode[i], ggc_alloc_string (buffer, -1));
1884 generating_concat_p = old_generating_concat_p;
1886 /* Now, for each output, construct an rtx
1887 (set OUTPUT (asm_operands INSN OUTPUTCONSTRAINT OUTPUTNUMBER
1888 ARGVEC CONSTRAINTS OPNAMES))
1889 If there is more than one, put them inside a PARALLEL. */
1891 if (noutputs == 1 && nclobbers == 0)
1893 ASM_OPERANDS_OUTPUT_CONSTRAINT (body) = constraints[0];
1894 insn = emit_insn (gen_rtx_SET (VOIDmode, output_rtx[0], body));
1897 else if (noutputs == 0 && nclobbers == 0)
1899 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1900 insn = emit_insn (body);
1911 body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers));
1913 /* For each output operand, store a SET. */
1914 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1916 XVECEXP (body, 0, i)
1917 = gen_rtx_SET (VOIDmode,
1919 gen_rtx_ASM_OPERANDS
1920 (GET_MODE (output_rtx[i]),
1921 TREE_STRING_POINTER (string),
1922 constraints[i], i, argvec, constraintvec,
1925 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1928 /* If there are no outputs (but there are some clobbers)
1929 store the bare ASM_OPERANDS into the PARALLEL. */
1932 XVECEXP (body, 0, i++) = obody;
1934 /* Store (clobber REG) for each clobbered register specified. */
1936 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1938 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1939 int j = decode_reg_name (regname);
1943 if (j == -3) /* `cc', which is not a register */
1946 if (j == -4) /* `memory', don't cache memory across asm */
1948 XVECEXP (body, 0, i++)
1949 = gen_rtx_CLOBBER (VOIDmode,
1952 gen_rtx_SCRATCH (VOIDmode)));
1956 /* Ignore unknown register, error already signaled. */
1960 /* Use QImode since that's guaranteed to clobber just one reg. */
1961 XVECEXP (body, 0, i++)
1962 = gen_rtx_CLOBBER (VOIDmode, gen_rtx_REG (QImode, j));
1965 insn = emit_insn (body);
1968 /* For any outputs that needed reloading into registers, spill them
1969 back to where they belong. */
1970 for (i = 0; i < noutputs; ++i)
1971 if (real_output_rtx[i])
1972 emit_move_insn (real_output_rtx[i], output_rtx[i]);
1977 /* A subroutine of expand_asm_operands. Check that all operands have
1978 the same number of alternatives. Return true if so. */
1981 check_operand_nalternatives (outputs, inputs)
1982 tree outputs, inputs;
1984 if (outputs || inputs)
1986 tree tmp = TREE_PURPOSE (outputs ? outputs : inputs);
1988 = n_occurrences (',', TREE_STRING_POINTER (TREE_VALUE (tmp)));
1991 if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES)
1993 error ("too many alternatives in `asm'");
2000 const char *constraint
2001 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tmp)));
2003 if (n_occurrences (',', constraint) != nalternatives)
2005 error ("operand constraints for `asm' differ in number of alternatives");
2009 if (TREE_CHAIN (tmp))
2010 tmp = TREE_CHAIN (tmp);
2012 tmp = next, next = 0;
2019 /* A subroutine of expand_asm_operands. Check that all operand names
2020 are unique. Return true if so. We rely on the fact that these names
2021 are identifiers, and so have been canonicalized by get_identifier,
2022 so all we need are pointer comparisons. */
2025 check_unique_operand_names (outputs, inputs)
2026 tree outputs, inputs;
2030 for (i = outputs; i ; i = TREE_CHAIN (i))
2032 tree i_name = TREE_PURPOSE (TREE_PURPOSE (i));
2036 for (j = TREE_CHAIN (i); j ; j = TREE_CHAIN (j))
2037 if (i_name == TREE_PURPOSE (TREE_PURPOSE (j)))
2041 for (i = inputs; i ; i = TREE_CHAIN (i))
2043 tree i_name = TREE_PURPOSE (TREE_PURPOSE (i));
2047 for (j = TREE_CHAIN (i); j ; j = TREE_CHAIN (j))
2048 if (i_name == TREE_PURPOSE (TREE_PURPOSE (j)))
2050 for (j = outputs; j ; j = TREE_CHAIN (j))
2051 if (i_name == TREE_PURPOSE (TREE_PURPOSE (j)))
2058 error ("duplicate asm operand name '%s'",
2059 IDENTIFIER_POINTER (TREE_PURPOSE (TREE_PURPOSE (i))));
2063 /* A subroutine of expand_asm_operands. Resolve the names of the operands
2064 in *POUTPUTS and *PINPUTS to numbers, and replace the name expansions in
2065 STRING and in the constraints to those numbers. */
2068 resolve_operand_names (string, outputs, inputs, pconstraints)
2070 tree outputs, inputs;
2071 const char **pconstraints;
2073 char *buffer = xstrdup (TREE_STRING_POINTER (string));
2077 /* Assume that we will not need extra space to perform the substitution.
2078 This because we get to remove '[' and ']', which means we cannot have
2079 a problem until we have more than 999 operands. */
2082 while ((p = strchr (p, '%')) != NULL)
2086 else if (ISALPHA (p[1]) && p[2] == '[')
2094 p = resolve_operand_name_1 (p, outputs, inputs);
2097 string = build_string (strlen (buffer), buffer);
2100 /* Collect output constraints here because it's convenient.
2101 There should be no named operands here; this is verified
2102 in expand_asm_operand. */
2103 for (t = outputs; t ; t = TREE_CHAIN (t), pconstraints++)
2104 *pconstraints = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t)));
2106 /* Substitute [<name>] in input constraint strings. */
2107 for (t = inputs; t ; t = TREE_CHAIN (t), pconstraints++)
2109 const char *c = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t)));
2110 if (strchr (c, '[') == NULL)
2114 p = buffer = xstrdup (c);
2115 while ((p = strchr (p, '[')) != NULL)
2116 p = resolve_operand_name_1 (p, outputs, inputs);
2118 *pconstraints = ggc_alloc_string (buffer, -1);
2126 /* A subroutine of resolve_operand_names. P points to the '[' for a
2127 potential named operand of the form [<name>]. In place, replace
2128 the name and brackets with a number. Return a pointer to the
2129 balance of the string after substitution. */
2132 resolve_operand_name_1 (p, outputs, inputs)
2134 tree outputs, inputs;
2141 /* Collect the operand name. */
2142 q = strchr (p, ']');
2145 error ("missing close brace for named operand");
2146 return strchr (p, '\0');
2150 /* Resolve the name to a number. */
2151 for (op = 0, t = outputs; t ; t = TREE_CHAIN (t), op++)
2153 tree id = TREE_PURPOSE (TREE_PURPOSE (t));
2156 const char *c = IDENTIFIER_POINTER (id);
2157 if (strncmp (c, p + 1, len) == 0 && c[len] == '\0')
2161 for (t = inputs; t ; t = TREE_CHAIN (t), op++)
2163 tree id = TREE_PURPOSE (TREE_PURPOSE (t));
2166 const char *c = IDENTIFIER_POINTER (id);
2167 if (strncmp (c, p + 1, len) == 0 && c[len] == '\0')
2173 error ("undefined named operand '%s'", p + 1);
2177 /* Replace the name with the number. Unfortunately, not all libraries
2178 get the return value of sprintf correct, so search for the end of the
2179 generated string by hand. */
2180 sprintf (p, "%d", op);
2181 p = strchr (p, '\0');
2183 /* Verify the no extra buffer space assumption. */
2187 /* Shift the rest of the buffer down to fill the gap. */
2188 memmove (p, q + 1, strlen (q + 1) + 1);
2193 /* Generate RTL to evaluate the expression EXP
2194 and remember it in case this is the VALUE in a ({... VALUE; }) constr.
2195 Provided just for backward-compatibility. expand_expr_stmt_value()
2196 should be used for new code. */
2199 expand_expr_stmt (exp)
2202 expand_expr_stmt_value (exp, -1, 1);
2205 /* Generate RTL to evaluate the expression EXP. WANT_VALUE tells
2206 whether to (1) save the value of the expression, (0) discard it or
2207 (-1) use expr_stmts_for_value to tell. The use of -1 is
2208 deprecated, and retained only for backward compatibility. */
2211 expand_expr_stmt_value (exp, want_value, maybe_last)
2213 int want_value, maybe_last;
2218 if (want_value == -1)
2219 want_value = expr_stmts_for_value != 0;
2221 /* If -W, warn about statements with no side effects,
2222 except for an explicit cast to void (e.g. for assert()), and
2223 except for last statement in ({...}) where they may be useful. */
2225 && (expr_stmts_for_value == 0 || ! maybe_last)
2226 && exp != error_mark_node)
2228 if (! TREE_SIDE_EFFECTS (exp))
2230 if ((extra_warnings || warn_unused_value)
2231 && !(TREE_CODE (exp) == CONVERT_EXPR
2232 && VOID_TYPE_P (TREE_TYPE (exp))))
2233 warning_with_file_and_line (emit_filename, emit_lineno,
2234 "statement with no effect");
2236 else if (warn_unused_value)
2237 warn_if_unused_value (exp);
2240 /* If EXP is of function type and we are expanding statements for
2241 value, convert it to pointer-to-function. */
2242 if (want_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
2243 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
2245 /* The call to `expand_expr' could cause last_expr_type and
2246 last_expr_value to get reset. Therefore, we set last_expr_value
2247 and last_expr_type *after* calling expand_expr. */
2248 value = expand_expr (exp, want_value ? NULL_RTX : const0_rtx,
2250 type = TREE_TYPE (exp);
2252 /* If all we do is reference a volatile value in memory,
2253 copy it to a register to be sure it is actually touched. */
2254 if (value && GET_CODE (value) == MEM && TREE_THIS_VOLATILE (exp))
2256 if (TYPE_MODE (type) == VOIDmode)
2258 else if (TYPE_MODE (type) != BLKmode)
2259 value = copy_to_reg (value);
2262 rtx lab = gen_label_rtx ();
2264 /* Compare the value with itself to reference it. */
2265 emit_cmp_and_jump_insns (value, value, EQ,
2266 expand_expr (TYPE_SIZE (type),
2267 NULL_RTX, VOIDmode, 0),
2273 /* If this expression is part of a ({...}) and is in memory, we may have
2274 to preserve temporaries. */
2275 preserve_temp_slots (value);
2277 /* Free any temporaries used to evaluate this expression. Any temporary
2278 used as a result of this expression will already have been preserved
2284 last_expr_value = value;
2285 last_expr_type = type;
2291 /* Warn if EXP contains any computations whose results are not used.
2292 Return 1 if a warning is printed; 0 otherwise. */
2295 warn_if_unused_value (exp)
2298 if (TREE_USED (exp))
2301 /* Don't warn about void constructs. This includes casting to void,
2302 void function calls, and statement expressions with a final cast
2304 if (VOID_TYPE_P (TREE_TYPE (exp)))
2307 switch (TREE_CODE (exp))
2309 case PREINCREMENT_EXPR:
2310 case POSTINCREMENT_EXPR:
2311 case PREDECREMENT_EXPR:
2312 case POSTDECREMENT_EXPR:
2317 case METHOD_CALL_EXPR:
2319 case TRY_CATCH_EXPR:
2320 case WITH_CLEANUP_EXPR:
2325 /* For a binding, warn if no side effect within it. */
2326 return warn_if_unused_value (TREE_OPERAND (exp, 1));
2329 return warn_if_unused_value (TREE_OPERAND (exp, 1));
2331 case TRUTH_ORIF_EXPR:
2332 case TRUTH_ANDIF_EXPR:
2333 /* In && or ||, warn if 2nd operand has no side effect. */
2334 return warn_if_unused_value (TREE_OPERAND (exp, 1));
2337 if (TREE_NO_UNUSED_WARNING (exp))
2339 if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
2341 /* Let people do `(foo (), 0)' without a warning. */
2342 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
2344 return warn_if_unused_value (TREE_OPERAND (exp, 1));
2348 case NON_LVALUE_EXPR:
2349 /* Don't warn about conversions not explicit in the user's program. */
2350 if (TREE_NO_UNUSED_WARNING (exp))
2352 /* Assignment to a cast usually results in a cast of a modify.
2353 Don't complain about that. There can be an arbitrary number of
2354 casts before the modify, so we must loop until we find the first
2355 non-cast expression and then test to see if that is a modify. */
2357 tree tem = TREE_OPERAND (exp, 0);
2359 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
2360 tem = TREE_OPERAND (tem, 0);
2362 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
2363 || TREE_CODE (tem) == CALL_EXPR)
2369 /* Don't warn about automatic dereferencing of references, since
2370 the user cannot control it. */
2371 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
2372 return warn_if_unused_value (TREE_OPERAND (exp, 0));
2376 /* Referencing a volatile value is a side effect, so don't warn. */
2378 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
2379 && TREE_THIS_VOLATILE (exp))
2382 /* If this is an expression which has no operands, there is no value
2383 to be unused. There are no such language-independent codes,
2384 but front ends may define such. */
2385 if (TREE_CODE_CLASS (TREE_CODE (exp)) == 'e'
2386 && TREE_CODE_LENGTH (TREE_CODE (exp)) == 0)
2390 /* If this is an expression with side effects, don't warn. */
2391 if (TREE_SIDE_EFFECTS (exp))
2394 warning_with_file_and_line (emit_filename, emit_lineno,
2395 "value computed is not used");
2400 /* Clear out the memory of the last expression evaluated. */
2408 /* Begin a statement which will return a value.
2409 Return the RTL_EXPR for this statement expr.
2410 The caller must save that value and pass it to expand_end_stmt_expr. */
2413 expand_start_stmt_expr ()
2417 /* Make the RTL_EXPR node temporary, not momentary,
2418 so that rtl_expr_chain doesn't become garbage. */
2419 t = make_node (RTL_EXPR);
2420 do_pending_stack_adjust ();
2421 start_sequence_for_rtl_expr (t);
2423 expr_stmts_for_value++;
2424 last_expr_value = NULL_RTX;
2428 /* Restore the previous state at the end of a statement that returns a value.
2429 Returns a tree node representing the statement's value and the
2430 insns to compute the value.
2432 The nodes of that expression have been freed by now, so we cannot use them.
2433 But we don't want to do that anyway; the expression has already been
2434 evaluated and now we just want to use the value. So generate a RTL_EXPR
2435 with the proper type and RTL value.
2437 If the last substatement was not an expression,
2438 return something with type `void'. */
2441 expand_end_stmt_expr (t)
2446 if (! last_expr_value || ! last_expr_type)
2448 last_expr_value = const0_rtx;
2449 last_expr_type = void_type_node;
2451 else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
2452 /* Remove any possible QUEUED. */
2453 last_expr_value = protect_from_queue (last_expr_value, 0);
2457 TREE_TYPE (t) = last_expr_type;
2458 RTL_EXPR_RTL (t) = last_expr_value;
2459 RTL_EXPR_SEQUENCE (t) = get_insns ();
2461 rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
2465 /* Don't consider deleting this expr or containing exprs at tree level. */
2466 TREE_SIDE_EFFECTS (t) = 1;
2467 /* Propagate volatility of the actual RTL expr. */
2468 TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
2471 expr_stmts_for_value--;
2476 /* Generate RTL for the start of an if-then. COND is the expression
2477 whose truth should be tested.
2479 If EXITFLAG is nonzero, this conditional is visible to
2480 `exit_something'. */
2483 expand_start_cond (cond, exitflag)
2487 struct nesting *thiscond = ALLOC_NESTING ();
2489 /* Make an entry on cond_stack for the cond we are entering. */
2491 thiscond->next = cond_stack;
2492 thiscond->all = nesting_stack;
2493 thiscond->depth = ++nesting_depth;
2494 thiscond->data.cond.next_label = gen_label_rtx ();
2495 /* Before we encounter an `else', we don't need a separate exit label
2496 unless there are supposed to be exit statements
2497 to exit this conditional. */
2498 thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
2499 thiscond->data.cond.endif_label = thiscond->exit_label;
2500 cond_stack = thiscond;
2501 nesting_stack = thiscond;
2503 do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
2506 /* Generate RTL between then-clause and the elseif-clause
2507 of an if-then-elseif-.... */
2510 expand_start_elseif (cond)
2513 if (cond_stack->data.cond.endif_label == 0)
2514 cond_stack->data.cond.endif_label = gen_label_rtx ();
2515 emit_jump (cond_stack->data.cond.endif_label);
2516 emit_label (cond_stack->data.cond.next_label);
2517 cond_stack->data.cond.next_label = gen_label_rtx ();
2518 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2521 /* Generate RTL between the then-clause and the else-clause
2522 of an if-then-else. */
2525 expand_start_else ()
2527 if (cond_stack->data.cond.endif_label == 0)
2528 cond_stack->data.cond.endif_label = gen_label_rtx ();
2530 emit_jump (cond_stack->data.cond.endif_label);
2531 emit_label (cond_stack->data.cond.next_label);
2532 cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
2535 /* After calling expand_start_else, turn this "else" into an "else if"
2536 by providing another condition. */
2539 expand_elseif (cond)
2542 cond_stack->data.cond.next_label = gen_label_rtx ();
2543 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2546 /* Generate RTL for the end of an if-then.
2547 Pop the record for it off of cond_stack. */
2552 struct nesting *thiscond = cond_stack;
2554 do_pending_stack_adjust ();
2555 if (thiscond->data.cond.next_label)
2556 emit_label (thiscond->data.cond.next_label);
2557 if (thiscond->data.cond.endif_label)
2558 emit_label (thiscond->data.cond.endif_label);
2560 POPSTACK (cond_stack);
2564 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2565 loop should be exited by `exit_something'. This is a loop for which
2566 `expand_continue' will jump to the top of the loop.
2568 Make an entry on loop_stack to record the labels associated with
2572 expand_start_loop (exit_flag)
2575 struct nesting *thisloop = ALLOC_NESTING ();
2577 /* Make an entry on loop_stack for the loop we are entering. */
2579 thisloop->next = loop_stack;
2580 thisloop->all = nesting_stack;
2581 thisloop->depth = ++nesting_depth;
2582 thisloop->data.loop.start_label = gen_label_rtx ();
2583 thisloop->data.loop.end_label = gen_label_rtx ();
2584 thisloop->data.loop.alt_end_label = 0;
2585 thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
2586 thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
2587 loop_stack = thisloop;
2588 nesting_stack = thisloop;
2590 do_pending_stack_adjust ();
2592 emit_note (NULL, NOTE_INSN_LOOP_BEG);
2593 emit_label (thisloop->data.loop.start_label);
2598 /* Like expand_start_loop but for a loop where the continuation point
2599 (for expand_continue_loop) will be specified explicitly. */
2602 expand_start_loop_continue_elsewhere (exit_flag)
2605 struct nesting *thisloop = expand_start_loop (exit_flag);
2606 loop_stack->data.loop.continue_label = gen_label_rtx ();
2610 /* Begin a null, aka do { } while (0) "loop". But since the contents
2611 of said loop can still contain a break, we must frob the loop nest. */
2614 expand_start_null_loop ()
2616 struct nesting *thisloop = ALLOC_NESTING ();
2618 /* Make an entry on loop_stack for the loop we are entering. */
2620 thisloop->next = loop_stack;
2621 thisloop->all = nesting_stack;
2622 thisloop->depth = ++nesting_depth;
2623 thisloop->data.loop.start_label = emit_note (NULL, NOTE_INSN_DELETED);
2624 thisloop->data.loop.end_label = gen_label_rtx ();
2625 thisloop->data.loop.alt_end_label = NULL_RTX;
2626 thisloop->data.loop.continue_label = thisloop->data.loop.end_label;
2627 thisloop->exit_label = thisloop->data.loop.end_label;
2628 loop_stack = thisloop;
2629 nesting_stack = thisloop;
2634 /* Specify the continuation point for a loop started with
2635 expand_start_loop_continue_elsewhere.
2636 Use this at the point in the code to which a continue statement
2640 expand_loop_continue_here ()
2642 do_pending_stack_adjust ();
2643 emit_note (NULL, NOTE_INSN_LOOP_CONT);
2644 emit_label (loop_stack->data.loop.continue_label);
2647 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2648 Pop the block off of loop_stack. */
2653 rtx start_label = loop_stack->data.loop.start_label;
2655 int eh_regions, debug_blocks;
2657 /* Mark the continue-point at the top of the loop if none elsewhere. */
2658 if (start_label == loop_stack->data.loop.continue_label)
2659 emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
2661 do_pending_stack_adjust ();
2663 /* If the loop starts with a loop exit, roll that to the end where
2664 it will optimize together with the jump back.
2666 If the loop presently looks like this (in pseudo-C):
2670 if (test) goto end_label;
2676 transform it to look like:
2683 if (test) goto end_label;
2687 We rely on the presence of NOTE_INSN_LOOP_END_TOP_COND to mark
2688 the end of the entry condtional. Without this, our lexical scan
2689 can't tell the difference between an entry conditional and a
2690 body conditional that exits the loop. Mistaking the two means
2691 that we can misplace the NOTE_INSN_LOOP_CONT note, which can
2692 screw up loop unrolling.
2694 Things will be oh so much better when loop optimization is done
2695 off of a proper control flow graph... */
2697 /* Scan insns from the top of the loop looking for the END_TOP_COND note. */
2699 eh_regions = debug_blocks = 0;
2700 for (etc_note = start_label; etc_note ; etc_note = NEXT_INSN (etc_note))
2701 if (GET_CODE (etc_note) == NOTE)
2703 if (NOTE_LINE_NUMBER (etc_note) == NOTE_INSN_LOOP_END_TOP_COND)
2706 /* We must not walk into a nested loop. */
2707 else if (NOTE_LINE_NUMBER (etc_note) == NOTE_INSN_LOOP_BEG)
2709 etc_note = NULL_RTX;
2713 /* At the same time, scan for EH region notes, as we don't want
2714 to scrog region nesting. This shouldn't happen, but... */
2715 else if (NOTE_LINE_NUMBER (etc_note) == NOTE_INSN_EH_REGION_BEG)
2717 else if (NOTE_LINE_NUMBER (etc_note) == NOTE_INSN_EH_REGION_END)
2719 if (--eh_regions < 0)
2720 /* We've come to the end of an EH region, but never saw the
2721 beginning of that region. That means that an EH region
2722 begins before the top of the loop, and ends in the middle
2723 of it. The existence of such a situation violates a basic
2724 assumption in this code, since that would imply that even
2725 when EH_REGIONS is zero, we might move code out of an
2726 exception region. */
2730 /* Likewise for debug scopes. In this case we'll either (1) move
2731 all of the notes if they are properly nested or (2) leave the
2732 notes alone and only rotate the loop at high optimization
2733 levels when we expect to scrog debug info. */
2734 else if (NOTE_LINE_NUMBER (etc_note) == NOTE_INSN_BLOCK_BEG)
2736 else if (NOTE_LINE_NUMBER (etc_note) == NOTE_INSN_BLOCK_END)
2743 && (debug_blocks == 0 || optimize >= 2)
2744 && NEXT_INSN (etc_note) != NULL_RTX
2745 && ! any_condjump_p (get_last_insn ()))
2747 /* We found one. Move everything from START to ETC to the end
2748 of the loop, and add a jump from the top of the loop. */
2749 rtx top_label = gen_label_rtx ();
2750 rtx start_move = start_label;
2752 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2753 then we want to move this note also. */
2754 if (GET_CODE (PREV_INSN (start_move)) == NOTE
2755 && NOTE_LINE_NUMBER (PREV_INSN (start_move)) == NOTE_INSN_LOOP_CONT)
2756 start_move = PREV_INSN (start_move);
2758 emit_label_before (top_label, start_move);
2760 /* Actually move the insns. If the debug scopes are nested, we
2761 can move everything at once. Otherwise we have to move them
2762 one by one and squeeze out the block notes. */
2763 if (debug_blocks == 0)
2764 reorder_insns (start_move, etc_note, get_last_insn ());
2767 rtx insn, next_insn;
2768 for (insn = start_move; insn; insn = next_insn)
2770 /* Figure out which insn comes after this one. We have
2771 to do this before we move INSN. */
2772 next_insn = (insn == etc_note ? NULL : NEXT_INSN (insn));
2774 if (GET_CODE (insn) == NOTE
2775 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2776 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2779 reorder_insns (insn, insn, get_last_insn ());
2783 /* Add the jump from the top of the loop. */
2784 emit_jump_insn_before (gen_jump (start_label), top_label);
2785 emit_barrier_before (top_label);
2786 start_label = top_label;
2789 emit_jump (start_label);
2790 emit_note (NULL, NOTE_INSN_LOOP_END);
2791 emit_label (loop_stack->data.loop.end_label);
2793 POPSTACK (loop_stack);
2798 /* Finish a null loop, aka do { } while (0). */
2801 expand_end_null_loop ()
2803 do_pending_stack_adjust ();
2804 emit_label (loop_stack->data.loop.end_label);
2806 POPSTACK (loop_stack);
2811 /* Generate a jump to the current loop's continue-point.
2812 This is usually the top of the loop, but may be specified
2813 explicitly elsewhere. If not currently inside a loop,
2814 return 0 and do nothing; caller will print an error message. */
2817 expand_continue_loop (whichloop)
2818 struct nesting *whichloop;
2822 whichloop = loop_stack;
2825 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
2830 /* Generate a jump to exit the current loop. If not currently inside a loop,
2831 return 0 and do nothing; caller will print an error message. */
2834 expand_exit_loop (whichloop)
2835 struct nesting *whichloop;
2839 whichloop = loop_stack;
2842 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
2846 /* Generate a conditional jump to exit the current loop if COND
2847 evaluates to zero. If not currently inside a loop,
2848 return 0 and do nothing; caller will print an error message. */
2851 expand_exit_loop_if_false (whichloop, cond)
2852 struct nesting *whichloop;
2855 rtx label = gen_label_rtx ();
2860 whichloop = loop_stack;
2863 /* In order to handle fixups, we actually create a conditional jump
2864 around an unconditional branch to exit the loop. If fixups are
2865 necessary, they go before the unconditional branch. */
2867 do_jump (cond, NULL_RTX, label);
2868 last_insn = get_last_insn ();
2869 if (GET_CODE (last_insn) == CODE_LABEL)
2870 whichloop->data.loop.alt_end_label = last_insn;
2871 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
2878 /* Like expand_exit_loop_if_false except also emit a note marking
2879 the end of the conditional. Should only be used immediately
2880 after expand_loop_start. */
2883 expand_exit_loop_top_cond (whichloop, cond)
2884 struct nesting *whichloop;
2887 if (! expand_exit_loop_if_false (whichloop, cond))
2890 emit_note (NULL, NOTE_INSN_LOOP_END_TOP_COND);
2894 /* Return nonzero if the loop nest is empty. Else return zero. */
2897 stmt_loop_nest_empty ()
2899 /* cfun->stmt can be NULL if we are building a call to get the
2900 EH context for a setjmp/longjmp EH target and the current
2901 function was a deferred inline function. */
2902 return (cfun->stmt == NULL || loop_stack == NULL);
2905 /* Return non-zero if we should preserve sub-expressions as separate
2906 pseudos. We never do so if we aren't optimizing. We always do so
2907 if -fexpensive-optimizations.
2909 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2910 the loop may still be a small one. */
2913 preserve_subexpressions_p ()
2917 if (flag_expensive_optimizations)
2920 if (optimize == 0 || cfun == 0 || cfun->stmt == 0 || loop_stack == 0)
2923 insn = get_last_insn_anywhere ();
2926 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
2927 < n_non_fixed_regs * 3));
2931 /* Generate a jump to exit the current loop, conditional, binding contour
2932 or case statement. Not all such constructs are visible to this function,
2933 only those started with EXIT_FLAG nonzero. Individual languages use
2934 the EXIT_FLAG parameter to control which kinds of constructs you can
2937 If not currently inside anything that can be exited,
2938 return 0 and do nothing; caller will print an error message. */
2941 expand_exit_something ()
2945 for (n = nesting_stack; n; n = n->all)
2946 if (n->exit_label != 0)
2948 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
2955 /* Generate RTL to return from the current function, with no value.
2956 (That is, we do not do anything about returning any value.) */
2959 expand_null_return ()
2961 rtx last_insn = get_last_insn ();
2963 /* If this function was declared to return a value, but we
2964 didn't, clobber the return registers so that they are not
2965 propagated live to the rest of the function. */
2966 clobber_return_register ();
2968 expand_null_return_1 (last_insn);
2971 /* Generate RTL to return from the current function, with value VAL. */
2974 expand_value_return (val)
2977 rtx last_insn = get_last_insn ();
2978 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2980 /* Copy the value to the return location
2981 unless it's already there. */
2983 if (return_reg != val)
2985 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
2986 #ifdef PROMOTE_FUNCTION_RETURN
2987 int unsignedp = TREE_UNSIGNED (type);
2988 enum machine_mode old_mode
2989 = DECL_MODE (DECL_RESULT (current_function_decl));
2990 enum machine_mode mode
2991 = promote_mode (type, old_mode, &unsignedp, 1);
2993 if (mode != old_mode)
2994 val = convert_modes (mode, old_mode, val, unsignedp);
2996 if (GET_CODE (return_reg) == PARALLEL)
2997 emit_group_load (return_reg, val, int_size_in_bytes (type));
2999 emit_move_insn (return_reg, val);
3002 expand_null_return_1 (last_insn);
3005 /* Output a return with no value. If LAST_INSN is nonzero,
3006 pretend that the return takes place after LAST_INSN. */
3009 expand_null_return_1 (last_insn)
3012 rtx end_label = cleanup_label ? cleanup_label : return_label;
3014 clear_pending_stack_adjust ();
3015 do_pending_stack_adjust ();
3019 end_label = return_label = gen_label_rtx ();
3020 expand_goto_internal (NULL_TREE, end_label, last_insn);
3023 /* Generate RTL to evaluate the expression RETVAL and return it
3024 from the current function. */
3027 expand_return (retval)
3030 /* If there are any cleanups to be performed, then they will
3031 be inserted following LAST_INSN. It is desirable
3032 that the last_insn, for such purposes, should be the
3033 last insn before computing the return value. Otherwise, cleanups
3034 which call functions can clobber the return value. */
3035 /* ??? rms: I think that is erroneous, because in C++ it would
3036 run destructors on variables that might be used in the subsequent
3037 computation of the return value. */
3043 /* If function wants no value, give it none. */
3044 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
3046 expand_expr (retval, NULL_RTX, VOIDmode, 0);
3048 expand_null_return ();
3052 if (retval == error_mark_node)
3054 /* Treat this like a return of no value from a function that
3056 expand_null_return ();
3059 else if (TREE_CODE (retval) == RESULT_DECL)
3060 retval_rhs = retval;
3061 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
3062 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
3063 retval_rhs = TREE_OPERAND (retval, 1);
3064 else if (VOID_TYPE_P (TREE_TYPE (retval)))
3065 /* Recognize tail-recursive call to void function. */
3066 retval_rhs = retval;
3068 retval_rhs = NULL_TREE;
3070 last_insn = get_last_insn ();
3072 /* Distribute return down conditional expr if either of the sides
3073 may involve tail recursion (see test below). This enhances the number
3074 of tail recursions we see. Don't do this always since it can produce
3075 sub-optimal code in some cases and we distribute assignments into
3076 conditional expressions when it would help. */
3078 if (optimize && retval_rhs != 0
3079 && frame_offset == 0
3080 && TREE_CODE (retval_rhs) == COND_EXPR
3081 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
3082 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
3084 rtx label = gen_label_rtx ();
3087 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
3088 start_cleanup_deferral ();
3089 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
3090 DECL_RESULT (current_function_decl),
3091 TREE_OPERAND (retval_rhs, 1));
3092 TREE_SIDE_EFFECTS (expr) = 1;
3093 expand_return (expr);
3096 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
3097 DECL_RESULT (current_function_decl),
3098 TREE_OPERAND (retval_rhs, 2));
3099 TREE_SIDE_EFFECTS (expr) = 1;
3100 expand_return (expr);
3101 end_cleanup_deferral ();
3105 result_rtl = DECL_RTL (DECL_RESULT (current_function_decl));
3107 /* If the result is an aggregate that is being returned in one (or more)
3108 registers, load the registers here. The compiler currently can't handle
3109 copying a BLKmode value into registers. We could put this code in a
3110 more general area (for use by everyone instead of just function
3111 call/return), but until this feature is generally usable it is kept here
3112 (and in expand_call). The value must go into a pseudo in case there
3113 are cleanups that will clobber the real return register. */
3116 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
3117 && GET_CODE (result_rtl) == REG)
3120 unsigned HOST_WIDE_INT bitpos, xbitpos;
3121 unsigned HOST_WIDE_INT big_endian_correction = 0;
3122 unsigned HOST_WIDE_INT bytes
3123 = int_size_in_bytes (TREE_TYPE (retval_rhs));
3124 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
3125 unsigned int bitsize
3126 = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)), BITS_PER_WORD);
3127 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
3128 rtx result_reg, src = NULL_RTX, dst = NULL_RTX;
3129 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
3130 enum machine_mode tmpmode, result_reg_mode;
3134 expand_null_return ();
3138 /* Structures whose size is not a multiple of a word are aligned
3139 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
3140 machine, this means we must skip the empty high order bytes when
3141 calculating the bit offset. */
3142 if (BYTES_BIG_ENDIAN
3143 && !FUNCTION_ARG_REG_LITTLE_ENDIAN
3144 && bytes % UNITS_PER_WORD)
3145 big_endian_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
3148 /* Copy the structure BITSIZE bits at a time. */
3149 for (bitpos = 0, xbitpos = big_endian_correction;
3150 bitpos < bytes * BITS_PER_UNIT;
3151 bitpos += bitsize, xbitpos += bitsize)
3153 /* We need a new destination pseudo each time xbitpos is
3154 on a word boundary and when xbitpos == big_endian_correction
3155 (the first time through). */
3156 if (xbitpos % BITS_PER_WORD == 0
3157 || xbitpos == big_endian_correction)
3159 /* Generate an appropriate register. */
3160 dst = gen_reg_rtx (word_mode);
3161 result_pseudos[xbitpos / BITS_PER_WORD] = dst;
3163 /* Clear the destination before we move anything into it. */
3164 emit_move_insn (dst, CONST0_RTX (GET_MODE (dst)));
3167 /* We need a new source operand each time bitpos is on a word
3169 if (bitpos % BITS_PER_WORD == 0)
3170 src = operand_subword_force (result_val,
3171 bitpos / BITS_PER_WORD,
3174 /* Use bitpos for the source extraction (left justified) and
3175 xbitpos for the destination store (right justified). */
3176 store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode,
3177 extract_bit_field (src, bitsize,
3178 bitpos % BITS_PER_WORD, 1,
3179 NULL_RTX, word_mode, word_mode,
3184 /* Find the smallest integer mode large enough to hold the
3185 entire structure and use that mode instead of BLKmode
3186 on the USE insn for the return register. */
3187 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
3188 tmpmode != VOIDmode;
3189 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
3190 /* Have we found a large enough mode? */
3191 if (GET_MODE_SIZE (tmpmode) >= bytes)
3194 /* No suitable mode found. */
3195 if (tmpmode == VOIDmode)
3198 PUT_MODE (result_rtl, tmpmode);
3200 if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
3201 result_reg_mode = word_mode;
3203 result_reg_mode = tmpmode;
3204 result_reg = gen_reg_rtx (result_reg_mode);
3207 for (i = 0; i < n_regs; i++)
3208 emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
3211 if (tmpmode != result_reg_mode)
3212 result_reg = gen_lowpart (tmpmode, result_reg);
3214 expand_value_return (result_reg);
3216 else if (retval_rhs != 0
3217 && !VOID_TYPE_P (TREE_TYPE (retval_rhs))
3218 && (GET_CODE (result_rtl) == REG
3219 || (GET_CODE (result_rtl) == PARALLEL)))
3221 /* Calculate the return value into a temporary (usually a pseudo
3223 tree ot = TREE_TYPE (DECL_RESULT (current_function_decl));
3224 tree nt = build_qualified_type (ot, TYPE_QUALS (ot) | TYPE_QUAL_CONST);
3226 val = assign_temp (nt, 0, 0, 1);
3227 val = expand_expr (retval_rhs, val, GET_MODE (val), 0);
3228 val = force_not_mem (val);
3230 /* Return the calculated value, doing cleanups first. */
3231 expand_value_return (val);
3235 /* No cleanups or no hard reg used;
3236 calculate value into hard return reg. */
3237 expand_expr (retval, const0_rtx, VOIDmode, 0);
3239 expand_value_return (result_rtl);
3243 /* Return 1 if the end of the generated RTX is not a barrier.
3244 This means code already compiled can drop through. */
3247 drop_through_at_end_p ()
3249 rtx insn = get_last_insn ();
3250 while (insn && GET_CODE (insn) == NOTE)
3251 insn = PREV_INSN (insn);
3252 return insn && GET_CODE (insn) != BARRIER;
3255 /* Attempt to optimize a potential tail recursion call into a goto.
3256 ARGUMENTS are the arguments to a CALL_EXPR; LAST_INSN indicates
3257 where to place the jump to the tail recursion label.
3259 Return TRUE if the call was optimized into a goto. */
3262 optimize_tail_recursion (arguments, last_insn)
3266 /* Finish checking validity, and if valid emit code to set the
3267 argument variables for the new call. */
3268 if (tail_recursion_args (arguments, DECL_ARGUMENTS (current_function_decl)))
3270 if (tail_recursion_label == 0)
3272 tail_recursion_label = gen_label_rtx ();
3273 emit_label_after (tail_recursion_label,
3274 tail_recursion_reentry);
3277 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
3284 /* Emit code to alter this function's formal parms for a tail-recursive call.
3285 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
3286 FORMALS is the chain of decls of formals.
3287 Return 1 if this can be done;
3288 otherwise return 0 and do not emit any code. */
3291 tail_recursion_args (actuals, formals)
3292 tree actuals, formals;
3294 tree a = actuals, f = formals;
3298 /* Check that number and types of actuals are compatible
3299 with the formals. This is not always true in valid C code.
3300 Also check that no formal needs to be addressable
3301 and that all formals are scalars. */
3303 /* Also count the args. */
3305 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
3307 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a)))
3308 != TYPE_MAIN_VARIANT (TREE_TYPE (f)))
3310 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
3313 if (a != 0 || f != 0)
3316 /* Compute all the actuals. */
3318 argvec = (rtx *) alloca (i * sizeof (rtx));
3320 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3321 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
3323 /* Find which actual values refer to current values of previous formals.
3324 Copy each of them now, before any formal is changed. */
3326 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3330 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
3331 if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
3337 argvec[i] = copy_to_reg (argvec[i]);
3340 /* Store the values of the actuals into the formals. */
3342 for (f = formals, a = actuals, i = 0; f;
3343 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
3345 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
3346 emit_move_insn (DECL_RTL (f), argvec[i]);
3348 convert_move (DECL_RTL (f), argvec[i],
3349 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
3356 /* Generate the RTL code for entering a binding contour.
3357 The variables are declared one by one, by calls to `expand_decl'.
3359 FLAGS is a bitwise or of the following flags:
3361 1 - Nonzero if this construct should be visible to
3364 2 - Nonzero if this contour does not require a
3365 NOTE_INSN_BLOCK_BEG note. Virtually all calls from
3366 language-independent code should set this flag because they
3367 will not create corresponding BLOCK nodes. (There should be
3368 a one-to-one correspondence between NOTE_INSN_BLOCK_BEG notes
3369 and BLOCKs.) If this flag is set, MARK_ENDS should be zero
3370 when expand_end_bindings is called.
3372 If we are creating a NOTE_INSN_BLOCK_BEG note, a BLOCK may
3373 optionally be supplied. If so, it becomes the NOTE_BLOCK for the
3377 expand_start_bindings_and_block (flags, block)
3381 struct nesting *thisblock = ALLOC_NESTING ();
3383 int exit_flag = ((flags & 1) != 0);
3384 int block_flag = ((flags & 2) == 0);
3386 /* If a BLOCK is supplied, then the caller should be requesting a
3387 NOTE_INSN_BLOCK_BEG note. */
3388 if (!block_flag && block)
3391 /* Create a note to mark the beginning of the block. */
3394 note = emit_note (NULL, NOTE_INSN_BLOCK_BEG);
3395 NOTE_BLOCK (note) = block;
3398 note = emit_note (NULL, NOTE_INSN_DELETED);
3400 /* Make an entry on block_stack for the block we are entering. */
3402 thisblock->next = block_stack;
3403 thisblock->all = nesting_stack;
3404 thisblock->depth = ++nesting_depth;
3405 thisblock->data.block.stack_level = 0;
3406 thisblock->data.block.cleanups = 0;
3407 thisblock->data.block.n_function_calls = 0;
3408 thisblock->data.block.exception_region = 0;
3409 thisblock->data.block.block_target_temp_slot_level = target_temp_slot_level;
3411 thisblock->data.block.conditional_code = 0;
3412 thisblock->data.block.last_unconditional_cleanup = note;
3413 /* When we insert instructions after the last unconditional cleanup,
3414 we don't adjust last_insn. That means that a later add_insn will
3415 clobber the instructions we've just added. The easiest way to
3416 fix this is to just insert another instruction here, so that the
3417 instructions inserted after the last unconditional cleanup are
3418 never the last instruction. */
3419 emit_note (NULL, NOTE_INSN_DELETED);
3420 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
3423 && !(block_stack->data.block.cleanups == NULL_TREE
3424 && block_stack->data.block.outer_cleanups == NULL_TREE))
3425 thisblock->data.block.outer_cleanups
3426 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
3427 block_stack->data.block.outer_cleanups);
3429 thisblock->data.block.outer_cleanups = 0;
3430 thisblock->data.block.label_chain = 0;
3431 thisblock->data.block.innermost_stack_block = stack_block_stack;
3432 thisblock->data.block.first_insn = note;
3433 thisblock->data.block.block_start_count = ++current_block_start_count;
3434 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
3435 block_stack = thisblock;
3436 nesting_stack = thisblock;
3438 /* Make a new level for allocating stack slots. */
3442 /* Specify the scope of temporaries created by TARGET_EXPRs. Similar
3443 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
3444 expand_expr are made. After we end the region, we know that all
3445 space for all temporaries that were created by TARGET_EXPRs will be
3446 destroyed and their space freed for reuse. */
3449 expand_start_target_temps ()
3451 /* This is so that even if the result is preserved, the space
3452 allocated will be freed, as we know that it is no longer in use. */
3455 /* Start a new binding layer that will keep track of all cleanup
3456 actions to be performed. */
3457 expand_start_bindings (2);
3459 target_temp_slot_level = temp_slot_level;
3463 expand_end_target_temps ()
3465 expand_end_bindings (NULL_TREE, 0, 0);
3467 /* This is so that even if the result is preserved, the space
3468 allocated will be freed, as we know that it is no longer in use. */
3472 /* Given a pointer to a BLOCK node return non-zero if (and only if) the node
3473 in question represents the outermost pair of curly braces (i.e. the "body
3474 block") of a function or method.
3476 For any BLOCK node representing a "body block" of a function or method, the
3477 BLOCK_SUPERCONTEXT of the node will point to another BLOCK node which
3478 represents the outermost (function) scope for the function or method (i.e.
3479 the one which includes the formal parameters). The BLOCK_SUPERCONTEXT of
3480 *that* node in turn will point to the relevant FUNCTION_DECL node. */
3483 is_body_block (stmt)
3486 if (TREE_CODE (stmt) == BLOCK)
3488 tree parent = BLOCK_SUPERCONTEXT (stmt);
3490 if (parent && TREE_CODE (parent) == BLOCK)
3492 tree grandparent = BLOCK_SUPERCONTEXT (parent);
3494 if (grandparent && TREE_CODE (grandparent) == FUNCTION_DECL)
3502 /* True if we are currently emitting insns in an area of output code
3503 that is controlled by a conditional expression. This is used by
3504 the cleanup handling code to generate conditional cleanup actions. */
3507 conditional_context ()
3509 return block_stack && block_stack->data.block.conditional_code;
3512 /* Return an opaque pointer to the current nesting level, so frontend code
3513 can check its own sanity. */
3516 current_nesting_level ()
3518 return cfun ? block_stack : 0;
3521 /* Emit a handler label for a nonlocal goto handler.
3522 Also emit code to store the handler label in SLOT before BEFORE_INSN. */
3525 expand_nl_handler_label (slot, before_insn)
3526 rtx slot, before_insn;
3529 rtx handler_label = gen_label_rtx ();
3531 /* Don't let cleanup_cfg delete the handler. */
3532 LABEL_PRESERVE_P (handler_label) = 1;
3535 emit_move_insn (slot, gen_rtx_LABEL_REF (Pmode, handler_label));
3536 insns = get_insns ();
3538 emit_insns_before (insns, before_insn);
3540 emit_label (handler_label);
3542 return handler_label;
3545 /* Emit code to restore vital registers at the beginning of a nonlocal goto
3548 expand_nl_goto_receiver ()
3550 #ifdef HAVE_nonlocal_goto
3551 if (! HAVE_nonlocal_goto)
3553 /* First adjust our frame pointer to its actual value. It was
3554 previously set to the start of the virtual area corresponding to
3555 the stacked variables when we branched here and now needs to be
3556 adjusted to the actual hardware fp value.
3558 Assignments are to virtual registers are converted by
3559 instantiate_virtual_regs into the corresponding assignment
3560 to the underlying register (fp in this case) that makes
3561 the original assignment true.
3562 So the following insn will actually be
3563 decrementing fp by STARTING_FRAME_OFFSET. */
3564 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
3566 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3567 if (fixed_regs[ARG_POINTER_REGNUM])
3569 #ifdef ELIMINABLE_REGS
3570 /* If the argument pointer can be eliminated in favor of the
3571 frame pointer, we don't need to restore it. We assume here
3572 that if such an elimination is present, it can always be used.
3573 This is the case on all known machines; if we don't make this
3574 assumption, we do unnecessary saving on many machines. */
3575 static const struct elims {const int from, to;} elim_regs[] = ELIMINABLE_REGS;
3578 for (i = 0; i < ARRAY_SIZE (elim_regs); i++)
3579 if (elim_regs[i].from == ARG_POINTER_REGNUM
3580 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3583 if (i == ARRAY_SIZE (elim_regs))
3586 /* Now restore our arg pointer from the address at which it
3587 was saved in our stack frame. */
3588 emit_move_insn (virtual_incoming_args_rtx,
3589 copy_to_reg (get_arg_pointer_save_area (cfun)));
3594 #ifdef HAVE_nonlocal_goto_receiver
3595 if (HAVE_nonlocal_goto_receiver)
3596 emit_insn (gen_nonlocal_goto_receiver ());
3600 /* Make handlers for nonlocal gotos taking place in the function calls in
3604 expand_nl_goto_receivers (thisblock)
3605 struct nesting *thisblock;
3608 rtx afterward = gen_label_rtx ();
3613 /* Record the handler address in the stack slot for that purpose,
3614 during this block, saving and restoring the outer value. */
3615 if (thisblock->next != 0)
3616 for (slot = nonlocal_goto_handler_slots; slot; slot = XEXP (slot, 1))
3618 rtx save_receiver = gen_reg_rtx (Pmode);
3619 emit_move_insn (XEXP (slot, 0), save_receiver);
3622 emit_move_insn (save_receiver, XEXP (slot, 0));
3623 insns = get_insns ();
3625 emit_insns_before (insns, thisblock->data.block.first_insn);
3628 /* Jump around the handlers; they run only when specially invoked. */
3629 emit_jump (afterward);
3631 /* Make a separate handler for each label. */
3632 link = nonlocal_labels;
3633 slot = nonlocal_goto_handler_slots;
3634 label_list = NULL_RTX;
3635 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3636 /* Skip any labels we shouldn't be able to jump to from here,
3637 we generate one special handler for all of them below which just calls
3639 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3642 lab = expand_nl_handler_label (XEXP (slot, 0),
3643 thisblock->data.block.first_insn);
3644 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3646 expand_nl_goto_receiver ();
3648 /* Jump to the "real" nonlocal label. */
3649 expand_goto (TREE_VALUE (link));
3652 /* A second pass over all nonlocal labels; this time we handle those
3653 we should not be able to jump to at this point. */
3654 link = nonlocal_labels;
3655 slot = nonlocal_goto_handler_slots;
3657 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3658 if (DECL_TOO_LATE (TREE_VALUE (link)))
3661 lab = expand_nl_handler_label (XEXP (slot, 0),
3662 thisblock->data.block.first_insn);
3663 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3669 expand_nl_goto_receiver ();
3670 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "abort"), LCT_NORETURN,
3675 nonlocal_goto_handler_labels = label_list;
3676 emit_label (afterward);
3679 /* Warn about any unused VARS (which may contain nodes other than
3680 VAR_DECLs, but such nodes are ignored). The nodes are connected
3681 via the TREE_CHAIN field. */
3684 warn_about_unused_variables (vars)
3689 if (warn_unused_variable)
3690 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3691 if (TREE_CODE (decl) == VAR_DECL
3692 && ! TREE_USED (decl)
3693 && ! DECL_IN_SYSTEM_HEADER (decl)
3694 && DECL_NAME (decl) && ! DECL_ARTIFICIAL (decl))
3695 warning_with_decl (decl, "unused variable `%s'");
3698 /* Generate RTL code to terminate a binding contour.
3700 VARS is the chain of VAR_DECL nodes for the variables bound in this
3701 contour. There may actually be other nodes in this chain, but any
3702 nodes other than VAR_DECLS are ignored.
3704 MARK_ENDS is nonzero if we should put a note at the beginning
3705 and end of this binding contour.
3707 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3708 (That is true automatically if the contour has a saved stack level.) */
3711 expand_end_bindings (vars, mark_ends, dont_jump_in)
3716 struct nesting *thisblock = block_stack;
3718 /* If any of the variables in this scope were not used, warn the
3720 warn_about_unused_variables (vars);
3722 if (thisblock->exit_label)
3724 do_pending_stack_adjust ();
3725 emit_label (thisblock->exit_label);
3728 /* If necessary, make handlers for nonlocal gotos taking
3729 place in the function calls in this block. */
3730 if (function_call_count != thisblock->data.block.n_function_calls
3732 /* Make handler for outermost block
3733 if there were any nonlocal gotos to this function. */
3734 && (thisblock->next == 0 ? current_function_has_nonlocal_label
3735 /* Make handler for inner block if it has something
3736 special to do when you jump out of it. */
3737 : (thisblock->data.block.cleanups != 0
3738 || thisblock->data.block.stack_level != 0)))
3739 expand_nl_goto_receivers (thisblock);
3741 /* Don't allow jumping into a block that has a stack level.
3742 Cleanups are allowed, though. */
3744 || thisblock->data.block.stack_level != 0)
3746 struct label_chain *chain;
3748 /* Any labels in this block are no longer valid to go to.
3749 Mark them to cause an error message. */
3750 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3752 DECL_TOO_LATE (chain->label) = 1;
3753 /* If any goto without a fixup came to this label,
3754 that must be an error, because gotos without fixups
3755 come from outside all saved stack-levels. */
3756 if (TREE_ADDRESSABLE (chain->label))
3757 error_with_decl (chain->label,
3758 "label `%s' used before containing binding contour");
3762 /* Restore stack level in effect before the block
3763 (only if variable-size objects allocated). */
3764 /* Perform any cleanups associated with the block. */
3766 if (thisblock->data.block.stack_level != 0
3767 || thisblock->data.block.cleanups != 0)
3772 /* Don't let cleanups affect ({...}) constructs. */
3773 int old_expr_stmts_for_value = expr_stmts_for_value;
3774 rtx old_last_expr_value = last_expr_value;
3775 tree old_last_expr_type = last_expr_type;
3776 expr_stmts_for_value = 0;
3778 /* Only clean up here if this point can actually be reached. */
3779 insn = get_last_insn ();
3780 if (GET_CODE (insn) == NOTE)
3781 insn = prev_nonnote_insn (insn);
3782 reachable = (! insn || GET_CODE (insn) != BARRIER);
3784 /* Do the cleanups. */
3785 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable);
3787 do_pending_stack_adjust ();
3789 expr_stmts_for_value = old_expr_stmts_for_value;
3790 last_expr_value = old_last_expr_value;
3791 last_expr_type = old_last_expr_type;
3793 /* Restore the stack level. */
3795 if (reachable && thisblock->data.block.stack_level != 0)
3797 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3798 thisblock->data.block.stack_level, NULL_RTX);
3799 if (nonlocal_goto_handler_slots != 0)
3800 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3804 /* Any gotos out of this block must also do these things.
3805 Also report any gotos with fixups that came to labels in this
3807 fixup_gotos (thisblock,
3808 thisblock->data.block.stack_level,
3809 thisblock->data.block.cleanups,
3810 thisblock->data.block.first_insn,
3814 /* Mark the beginning and end of the scope if requested.
3815 We do this now, after running cleanups on the variables
3816 just going out of scope, so they are in scope for their cleanups. */
3820 rtx note = emit_note (NULL, NOTE_INSN_BLOCK_END);
3821 NOTE_BLOCK (note) = NOTE_BLOCK (thisblock->data.block.first_insn);
3824 /* Get rid of the beginning-mark if we don't make an end-mark. */
3825 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3827 /* Restore the temporary level of TARGET_EXPRs. */
3828 target_temp_slot_level = thisblock->data.block.block_target_temp_slot_level;
3830 /* Restore block_stack level for containing block. */
3832 stack_block_stack = thisblock->data.block.innermost_stack_block;
3833 POPSTACK (block_stack);
3835 /* Pop the stack slot nesting and free any slots at this level. */
3839 /* Generate code to save the stack pointer at the start of the current block
3840 and set up to restore it on exit. */
3843 save_stack_pointer ()
3845 struct nesting *thisblock = block_stack;
3847 if (thisblock->data.block.stack_level == 0)
3849 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3850 &thisblock->data.block.stack_level,
3851 thisblock->data.block.first_insn);
3852 stack_block_stack = thisblock;
3856 /* Generate RTL for the automatic variable declaration DECL.
3857 (Other kinds of declarations are simply ignored if seen here.) */
3863 struct nesting *thisblock;
3866 type = TREE_TYPE (decl);
3868 /* For a CONST_DECL, set mode, alignment, and sizes from those of the
3869 type in case this node is used in a reference. */
3870 if (TREE_CODE (decl) == CONST_DECL)
3872 DECL_MODE (decl) = TYPE_MODE (type);
3873 DECL_ALIGN (decl) = TYPE_ALIGN (type);
3874 DECL_SIZE (decl) = TYPE_SIZE (type);
3875 DECL_SIZE_UNIT (decl) = TYPE_SIZE_UNIT (type);
3879 /* Otherwise, only automatic variables need any expansion done. Static and
3880 external variables, and external functions, will be handled by
3881 `assemble_variable' (called from finish_decl). TYPE_DECL requires
3882 nothing. PARM_DECLs are handled in `assign_parms'. */
3883 if (TREE_CODE (decl) != VAR_DECL)
3886 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3889 thisblock = block_stack;
3891 /* Create the RTL representation for the variable. */
3893 if (type == error_mark_node)
3894 SET_DECL_RTL (decl, gen_rtx_MEM (BLKmode, const0_rtx));
3896 else if (DECL_SIZE (decl) == 0)
3897 /* Variable with incomplete type. */
3900 if (DECL_INITIAL (decl) == 0)
3901 /* Error message was already done; now avoid a crash. */
3902 x = gen_rtx_MEM (BLKmode, const0_rtx);
3904 /* An initializer is going to decide the size of this array.
3905 Until we know the size, represent its address with a reg. */
3906 x = gen_rtx_MEM (BLKmode, gen_reg_rtx (Pmode));
3908 set_mem_attributes (x, decl, 1);
3909 SET_DECL_RTL (decl, x);
3911 else if (DECL_MODE (decl) != BLKmode
3912 /* If -ffloat-store, don't put explicit float vars
3914 && !(flag_float_store
3915 && TREE_CODE (type) == REAL_TYPE)
3916 && ! TREE_THIS_VOLATILE (decl)
3917 && (DECL_REGISTER (decl) || optimize))
3919 /* Automatic variable that can go in a register. */
3920 int unsignedp = TREE_UNSIGNED (type);
3921 enum machine_mode reg_mode
3922 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3924 SET_DECL_RTL (decl, gen_reg_rtx (reg_mode));
3926 if (GET_CODE (DECL_RTL (decl)) == REG)
3927 REGNO_DECL (REGNO (DECL_RTL (decl))) = decl;
3928 else if (GET_CODE (DECL_RTL (decl)) == CONCAT)
3930 REGNO_DECL (REGNO (XEXP (DECL_RTL (decl), 0))) = decl;
3931 REGNO_DECL (REGNO (XEXP (DECL_RTL (decl), 1))) = decl;
3934 mark_user_reg (DECL_RTL (decl));
3936 if (POINTER_TYPE_P (type))
3937 mark_reg_pointer (DECL_RTL (decl),
3938 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
3940 maybe_set_unchanging (DECL_RTL (decl), decl);
3942 /* If something wants our address, try to use ADDRESSOF. */
3943 if (TREE_ADDRESSABLE (decl))
3944 put_var_into_stack (decl);
3947 else if (TREE_CODE (DECL_SIZE_UNIT (decl)) == INTEGER_CST
3948 && ! (flag_stack_check && ! STACK_CHECK_BUILTIN
3949 && 0 < compare_tree_int (DECL_SIZE_UNIT (decl),
3950 STACK_CHECK_MAX_VAR_SIZE)))
3952 /* Variable of fixed size that goes on the stack. */
3957 /* If we previously made RTL for this decl, it must be an array
3958 whose size was determined by the initializer.
3959 The old address was a register; set that register now
3960 to the proper address. */
3961 if (DECL_RTL_SET_P (decl))
3963 if (GET_CODE (DECL_RTL (decl)) != MEM
3964 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3966 oldaddr = XEXP (DECL_RTL (decl), 0);
3969 /* Set alignment we actually gave this decl. */
3970 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3971 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3972 DECL_USER_ALIGN (decl) = 0;
3974 x = assign_temp (TREE_TYPE (decl), 1, 1, 1);
3975 set_mem_attributes (x, decl, 1);
3976 SET_DECL_RTL (decl, x);
3980 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3981 if (addr != oldaddr)
3982 emit_move_insn (oldaddr, addr);
3986 /* Dynamic-size object: must push space on the stack. */
3988 rtx address, size, x;
3990 /* Record the stack pointer on entry to block, if have
3991 not already done so. */
3992 do_pending_stack_adjust ();
3993 save_stack_pointer ();
3995 /* In function-at-a-time mode, variable_size doesn't expand this,
3997 if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
3998 expand_expr (TYPE_MAX_VALUE (TYPE_DOMAIN (type)),
3999 const0_rtx, VOIDmode, 0);
4001 /* Compute the variable's size, in bytes. */
4002 size = expand_expr (DECL_SIZE_UNIT (decl), NULL_RTX, VOIDmode, 0);
4005 /* Allocate space on the stack for the variable. Note that
4006 DECL_ALIGN says how the variable is to be aligned and we
4007 cannot use it to conclude anything about the alignment of
4009 address = allocate_dynamic_stack_space (size, NULL_RTX,
4010 TYPE_ALIGN (TREE_TYPE (decl)));
4012 /* Reference the variable indirect through that rtx. */
4013 x = gen_rtx_MEM (DECL_MODE (decl), address);
4014 set_mem_attributes (x, decl, 1);
4015 SET_DECL_RTL (decl, x);
4018 /* Indicate the alignment we actually gave this variable. */
4019 #ifdef STACK_BOUNDARY
4020 DECL_ALIGN (decl) = STACK_BOUNDARY;
4022 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
4024 DECL_USER_ALIGN (decl) = 0;
4028 /* Emit code to perform the initialization of a declaration DECL. */
4031 expand_decl_init (decl)
4034 int was_used = TREE_USED (decl);
4036 /* If this is a CONST_DECL, we don't have to generate any code. Likewise
4037 for static decls. */
4038 if (TREE_CODE (decl) == CONST_DECL
4039 || TREE_STATIC (decl))
4042 /* Compute and store the initial value now. */
4044 if (DECL_INITIAL (decl) == error_mark_node)
4046 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
4048 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
4049 || code == POINTER_TYPE || code == REFERENCE_TYPE)
4050 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
4054 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
4056 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
4057 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
4061 /* Don't let the initialization count as "using" the variable. */
4062 TREE_USED (decl) = was_used;
4064 /* Free any temporaries we made while initializing the decl. */
4065 preserve_temp_slots (NULL_RTX);
4069 /* CLEANUP is an expression to be executed at exit from this binding contour;
4070 for example, in C++, it might call the destructor for this variable.
4072 We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
4073 CLEANUP multiple times, and have the correct semantics. This
4074 happens in exception handling, for gotos, returns, breaks that
4075 leave the current scope.
4077 If CLEANUP is nonzero and DECL is zero, we record a cleanup
4078 that is not associated with any particular variable. */
4081 expand_decl_cleanup (decl, cleanup)
4084 struct nesting *thisblock;
4086 /* Error if we are not in any block. */
4087 if (cfun == 0 || block_stack == 0)
4090 thisblock = block_stack;
4092 /* Record the cleanup if there is one. */
4098 tree *cleanups = &thisblock->data.block.cleanups;
4099 int cond_context = conditional_context ();
4103 rtx flag = gen_reg_rtx (word_mode);
4108 emit_move_insn (flag, const0_rtx);
4109 set_flag_0 = get_insns ();
4112 thisblock->data.block.last_unconditional_cleanup
4113 = emit_insns_after (set_flag_0,
4114 thisblock->data.block.last_unconditional_cleanup);
4116 emit_move_insn (flag, const1_rtx);
4118 cond = build_decl (VAR_DECL, NULL_TREE,
4119 (*lang_hooks.types.type_for_mode) (word_mode, 1));
4120 SET_DECL_RTL (cond, flag);
4122 /* Conditionalize the cleanup. */
4123 cleanup = build (COND_EXPR, void_type_node,
4124 truthvalue_conversion (cond),
4125 cleanup, integer_zero_node);
4126 cleanup = fold (cleanup);
4128 cleanups = thisblock->data.block.cleanup_ptr;
4131 cleanup = unsave_expr (cleanup);
4133 t = *cleanups = tree_cons (decl, cleanup, *cleanups);
4136 /* If this block has a cleanup, it belongs in stack_block_stack. */
4137 stack_block_stack = thisblock;
4144 if (! using_eh_for_cleanups_p)
4145 TREE_ADDRESSABLE (t) = 1;
4147 expand_eh_region_start ();
4154 thisblock->data.block.last_unconditional_cleanup
4155 = emit_insns_after (seq,
4156 thisblock->data.block.last_unconditional_cleanup);
4160 thisblock->data.block.last_unconditional_cleanup
4162 /* When we insert instructions after the last unconditional cleanup,
4163 we don't adjust last_insn. That means that a later add_insn will
4164 clobber the instructions we've just added. The easiest way to
4165 fix this is to just insert another instruction here, so that the
4166 instructions inserted after the last unconditional cleanup are
4167 never the last instruction. */
4168 emit_note (NULL, NOTE_INSN_DELETED);
4169 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
4175 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
4176 DECL_ELTS is the list of elements that belong to DECL's type.
4177 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
4180 expand_anon_union_decl (decl, cleanup, decl_elts)
4181 tree decl, cleanup, decl_elts;
4183 struct nesting *thisblock = cfun == 0 ? 0 : block_stack;
4187 /* If any of the elements are addressable, so is the entire union. */
4188 for (t = decl_elts; t; t = TREE_CHAIN (t))
4189 if (TREE_ADDRESSABLE (TREE_VALUE (t)))
4191 TREE_ADDRESSABLE (decl) = 1;
4196 expand_decl_cleanup (decl, cleanup);
4197 x = DECL_RTL (decl);
4199 /* Go through the elements, assigning RTL to each. */
4200 for (t = decl_elts; t; t = TREE_CHAIN (t))
4202 tree decl_elt = TREE_VALUE (t);
4203 tree cleanup_elt = TREE_PURPOSE (t);
4204 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
4206 /* If any of the elements are addressable, so is the entire
4208 if (TREE_USED (decl_elt))
4209 TREE_USED (decl) = 1;
4211 /* Propagate the union's alignment to the elements. */
4212 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
4213 DECL_USER_ALIGN (decl_elt) = DECL_USER_ALIGN (decl);
4215 /* If the element has BLKmode and the union doesn't, the union is
4216 aligned such that the element doesn't need to have BLKmode, so
4217 change the element's mode to the appropriate one for its size. */
4218 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
4219 DECL_MODE (decl_elt) = mode
4220 = mode_for_size_tree (DECL_SIZE (decl_elt), MODE_INT, 1);
4222 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
4223 instead create a new MEM rtx with the proper mode. */
4224 if (GET_CODE (x) == MEM)
4226 if (mode == GET_MODE (x))
4227 SET_DECL_RTL (decl_elt, x);
4229 SET_DECL_RTL (decl_elt, adjust_address_nv (x, mode, 0));
4231 else if (GET_CODE (x) == REG)
4233 if (mode == GET_MODE (x))
4234 SET_DECL_RTL (decl_elt, x);
4236 SET_DECL_RTL (decl_elt, gen_lowpart_SUBREG (mode, x));
4241 /* Record the cleanup if there is one. */
4244 thisblock->data.block.cleanups
4245 = tree_cons (decl_elt, cleanup_elt,
4246 thisblock->data.block.cleanups);
4250 /* Expand a list of cleanups LIST.
4251 Elements may be expressions or may be nested lists.
4253 If DONT_DO is nonnull, then any list-element
4254 whose TREE_PURPOSE matches DONT_DO is omitted.
4255 This is sometimes used to avoid a cleanup associated with
4256 a value that is being returned out of the scope.
4258 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
4259 goto and handle protection regions specially in that case.
4261 If REACHABLE, we emit code, otherwise just inform the exception handling
4262 code about this finalization. */
4265 expand_cleanups (list, dont_do, in_fixup, reachable)
4272 for (tail = list; tail; tail = TREE_CHAIN (tail))
4273 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
4275 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
4276 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable);
4279 if (! in_fixup && using_eh_for_cleanups_p)
4280 expand_eh_region_end_cleanup (TREE_VALUE (tail));
4284 /* Cleanups may be run multiple times. For example,
4285 when exiting a binding contour, we expand the
4286 cleanups associated with that contour. When a goto
4287 within that binding contour has a target outside that
4288 contour, it will expand all cleanups from its scope to
4289 the target. Though the cleanups are expanded multiple
4290 times, the control paths are non-overlapping so the
4291 cleanups will not be executed twice. */
4293 /* We may need to protect from outer cleanups. */
4294 if (in_fixup && using_eh_for_cleanups_p)
4296 expand_eh_region_start ();
4298 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
4300 expand_eh_region_end_fixup (TREE_VALUE (tail));
4303 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
4311 /* Mark when the context we are emitting RTL for as a conditional
4312 context, so that any cleanup actions we register with
4313 expand_decl_init will be properly conditionalized when those
4314 cleanup actions are later performed. Must be called before any
4315 expression (tree) is expanded that is within a conditional context. */
4318 start_cleanup_deferral ()
4320 /* block_stack can be NULL if we are inside the parameter list. It is
4321 OK to do nothing, because cleanups aren't possible here. */
4323 ++block_stack->data.block.conditional_code;
4326 /* Mark the end of a conditional region of code. Because cleanup
4327 deferrals may be nested, we may still be in a conditional region
4328 after we end the currently deferred cleanups, only after we end all
4329 deferred cleanups, are we back in unconditional code. */
4332 end_cleanup_deferral ()
4334 /* block_stack can be NULL if we are inside the parameter list. It is
4335 OK to do nothing, because cleanups aren't possible here. */
4337 --block_stack->data.block.conditional_code;
4340 /* Move all cleanups from the current block_stack
4341 to the containing block_stack, where they are assumed to
4342 have been created. If anything can cause a temporary to
4343 be created, but not expanded for more than one level of
4344 block_stacks, then this code will have to change. */
4349 struct nesting *block = block_stack;
4350 struct nesting *outer = block->next;
4352 outer->data.block.cleanups
4353 = chainon (block->data.block.cleanups,
4354 outer->data.block.cleanups);
4355 block->data.block.cleanups = 0;
4359 last_cleanup_this_contour ()
4361 if (block_stack == 0)
4364 return block_stack->data.block.cleanups;
4367 /* Return 1 if there are any pending cleanups at this point.
4368 If THIS_CONTOUR is nonzero, check the current contour as well.
4369 Otherwise, look only at the contours that enclose this one. */
4372 any_pending_cleanups (this_contour)
4375 struct nesting *block;
4377 if (cfun == NULL || cfun->stmt == NULL || block_stack == 0)
4380 if (this_contour && block_stack->data.block.cleanups != NULL)
4382 if (block_stack->data.block.cleanups == 0
4383 && block_stack->data.block.outer_cleanups == 0)
4386 for (block = block_stack->next; block; block = block->next)
4387 if (block->data.block.cleanups != 0)
4393 /* Enter a case (Pascal) or switch (C) statement.
4394 Push a block onto case_stack and nesting_stack
4395 to accumulate the case-labels that are seen
4396 and to record the labels generated for the statement.
4398 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
4399 Otherwise, this construct is transparent for `exit_something'.
4401 EXPR is the index-expression to be dispatched on.
4402 TYPE is its nominal type. We could simply convert EXPR to this type,
4403 but instead we take short cuts. */
4406 expand_start_case (exit_flag, expr, type, printname)
4410 const char *printname;
4412 struct nesting *thiscase = ALLOC_NESTING ();
4414 /* Make an entry on case_stack for the case we are entering. */
4416 thiscase->next = case_stack;
4417 thiscase->all = nesting_stack;
4418 thiscase->depth = ++nesting_depth;
4419 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
4420 thiscase->data.case_stmt.case_list = 0;
4421 thiscase->data.case_stmt.index_expr = expr;
4422 thiscase->data.case_stmt.nominal_type = type;
4423 thiscase->data.case_stmt.default_label = 0;
4424 thiscase->data.case_stmt.printname = printname;
4425 thiscase->data.case_stmt.line_number_status = force_line_numbers ();
4426 case_stack = thiscase;
4427 nesting_stack = thiscase;
4429 do_pending_stack_adjust ();
4431 /* Make sure case_stmt.start points to something that won't
4432 need any transformation before expand_end_case. */
4433 if (GET_CODE (get_last_insn ()) != NOTE)
4434 emit_note (NULL, NOTE_INSN_DELETED);
4436 thiscase->data.case_stmt.start = get_last_insn ();
4438 start_cleanup_deferral ();
4441 /* Start a "dummy case statement" within which case labels are invalid
4442 and are not connected to any larger real case statement.
4443 This can be used if you don't want to let a case statement jump
4444 into the middle of certain kinds of constructs. */
4447 expand_start_case_dummy ()
4449 struct nesting *thiscase = ALLOC_NESTING ();
4451 /* Make an entry on case_stack for the dummy. */
4453 thiscase->next = case_stack;
4454 thiscase->all = nesting_stack;
4455 thiscase->depth = ++nesting_depth;
4456 thiscase->exit_label = 0;
4457 thiscase->data.case_stmt.case_list = 0;
4458 thiscase->data.case_stmt.start = 0;
4459 thiscase->data.case_stmt.nominal_type = 0;
4460 thiscase->data.case_stmt.default_label = 0;
4461 case_stack = thiscase;
4462 nesting_stack = thiscase;
4463 start_cleanup_deferral ();
4466 /* End a dummy case statement. */
4469 expand_end_case_dummy ()
4471 end_cleanup_deferral ();
4472 POPSTACK (case_stack);
4475 /* Return the data type of the index-expression
4476 of the innermost case statement, or null if none. */
4479 case_index_expr_type ()
4482 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
4489 /* If this is the first label, warn if any insns have been emitted. */
4490 if (case_stack->data.case_stmt.line_number_status >= 0)
4494 restore_line_number_status
4495 (case_stack->data.case_stmt.line_number_status);
4496 case_stack->data.case_stmt.line_number_status = -1;
4498 for (insn = case_stack->data.case_stmt.start;
4500 insn = NEXT_INSN (insn))
4502 if (GET_CODE (insn) == CODE_LABEL)
4504 if (GET_CODE (insn) != NOTE
4505 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4508 insn = PREV_INSN (insn);
4509 while (insn && (GET_CODE (insn) != NOTE || NOTE_LINE_NUMBER (insn) < 0));
4511 /* If insn is zero, then there must have been a syntax error. */
4513 warning_with_file_and_line (NOTE_SOURCE_FILE (insn),
4514 NOTE_LINE_NUMBER (insn),
4515 "unreachable code at beginning of %s",
4516 case_stack->data.case_stmt.printname);
4523 /* Accumulate one case or default label inside a case or switch statement.
4524 VALUE is the value of the case (a null pointer, for a default label).
4525 The function CONVERTER, when applied to arguments T and V,
4526 converts the value V to the type T.
4528 If not currently inside a case or switch statement, return 1 and do
4529 nothing. The caller will print a language-specific error message.
4530 If VALUE is a duplicate or overlaps, return 2 and do nothing
4531 except store the (first) duplicate node in *DUPLICATE.
4532 If VALUE is out of range, return 3 and do nothing.
4533 If we are jumping into the scope of a cleanup or var-sized array, return 5.
4534 Return 0 on success.
4536 Extended to handle range statements. */
4539 pushcase (value, converter, label, duplicate)
4541 tree (*converter) PARAMS ((tree, tree));
4548 /* Fail if not inside a real case statement. */
4549 if (! (case_stack && case_stack->data.case_stmt.start))
4552 if (stack_block_stack
4553 && stack_block_stack->depth > case_stack->depth)
4556 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4557 nominal_type = case_stack->data.case_stmt.nominal_type;
4559 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4560 if (index_type == error_mark_node)
4563 /* Convert VALUE to the type in which the comparisons are nominally done. */
4565 value = (*converter) (nominal_type, value);
4569 /* Fail if this value is out of range for the actual type of the index
4570 (which may be narrower than NOMINAL_TYPE). */
4572 && (TREE_CONSTANT_OVERFLOW (value)
4573 || ! int_fits_type_p (value, index_type)))
4576 return add_case_node (value, value, label, duplicate);
4579 /* Like pushcase but this case applies to all values between VALUE1 and
4580 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
4581 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
4582 starts at VALUE1 and ends at the highest value of the index type.
4583 If both are NULL, this case applies to all values.
4585 The return value is the same as that of pushcase but there is one
4586 additional error code: 4 means the specified range was empty. */
4589 pushcase_range (value1, value2, converter, label, duplicate)
4590 tree value1, value2;
4591 tree (*converter) PARAMS ((tree, tree));
4598 /* Fail if not inside a real case statement. */
4599 if (! (case_stack && case_stack->data.case_stmt.start))
4602 if (stack_block_stack
4603 && stack_block_stack->depth > case_stack->depth)
4606 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4607 nominal_type = case_stack->data.case_stmt.nominal_type;
4609 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4610 if (index_type == error_mark_node)
4615 /* Convert VALUEs to type in which the comparisons are nominally done
4616 and replace any unspecified value with the corresponding bound. */
4618 value1 = TYPE_MIN_VALUE (index_type);
4620 value2 = TYPE_MAX_VALUE (index_type);
4622 /* Fail if the range is empty. Do this before any conversion since
4623 we want to allow out-of-range empty ranges. */
4624 if (value2 != 0 && tree_int_cst_lt (value2, value1))
4627 /* If the max was unbounded, use the max of the nominal_type we are
4628 converting to. Do this after the < check above to suppress false
4631 value2 = TYPE_MAX_VALUE (nominal_type);
4633 value1 = (*converter) (nominal_type, value1);
4634 value2 = (*converter) (nominal_type, value2);
4636 /* Fail if these values are out of range. */
4637 if (TREE_CONSTANT_OVERFLOW (value1)
4638 || ! int_fits_type_p (value1, index_type))
4641 if (TREE_CONSTANT_OVERFLOW (value2)
4642 || ! int_fits_type_p (value2, index_type))
4645 return add_case_node (value1, value2, label, duplicate);
4648 /* Do the actual insertion of a case label for pushcase and pushcase_range
4649 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4650 slowdown for large switch statements. */
4653 add_case_node (low, high, label, duplicate)
4658 struct case_node *p, **q, *r;
4660 /* If there's no HIGH value, then this is not a case range; it's
4661 just a simple case label. But that's just a degenerate case
4666 /* Handle default labels specially. */
4669 if (case_stack->data.case_stmt.default_label != 0)
4671 *duplicate = case_stack->data.case_stmt.default_label;
4674 case_stack->data.case_stmt.default_label = label;
4675 expand_label (label);
4679 q = &case_stack->data.case_stmt.case_list;
4686 /* Keep going past elements distinctly greater than HIGH. */
4687 if (tree_int_cst_lt (high, p->low))
4690 /* or distinctly less than LOW. */
4691 else if (tree_int_cst_lt (p->high, low))
4696 /* We have an overlap; this is an error. */
4697 *duplicate = p->code_label;
4702 /* Add this label to the chain, and succeed. */
4704 r = (struct case_node *) xmalloc (sizeof (struct case_node));
4707 /* If the bounds are equal, turn this into the one-value case. */
4708 if (tree_int_cst_equal (low, high))
4713 r->code_label = label;
4714 expand_label (label);
4724 struct case_node *s;
4730 if (! (b = p->balance))
4731 /* Growth propagation from left side. */
4738 if ((p->left = s = r->right))
4747 if ((r->parent = s))
4755 case_stack->data.case_stmt.case_list = r;
4758 /* r->balance == +1 */
4763 struct case_node *t = r->right;
4765 if ((p->left = s = t->right))
4769 if ((r->right = s = t->left))
4783 if ((t->parent = s))
4791 case_stack->data.case_stmt.case_list = t;
4798 /* p->balance == +1; growth of left side balances the node. */
4808 if (! (b = p->balance))
4809 /* Growth propagation from right side. */
4817 if ((p->right = s = r->left))
4825 if ((r->parent = s))
4834 case_stack->data.case_stmt.case_list = r;
4838 /* r->balance == -1 */
4842 struct case_node *t = r->left;
4844 if ((p->right = s = t->left))
4849 if ((r->left = s = t->right))
4863 if ((t->parent = s))
4872 case_stack->data.case_stmt.case_list = t;
4878 /* p->balance == -1; growth of right side balances the node. */
4891 /* Returns the number of possible values of TYPE.
4892 Returns -1 if the number is unknown, variable, or if the number does not
4893 fit in a HOST_WIDE_INT.
4894 Sets *SPARSENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4895 do not increase monotonically (there may be duplicates);
4896 to 1 if the values increase monotonically, but not always by 1;
4897 otherwise sets it to 0. */
4900 all_cases_count (type, sparseness)
4905 HOST_WIDE_INT count, minval, lastval;
4909 switch (TREE_CODE (type))
4916 count = 1 << BITS_PER_UNIT;
4921 if (TYPE_MAX_VALUE (type) != 0
4922 && 0 != (t = fold (build (MINUS_EXPR, type, TYPE_MAX_VALUE (type),
4923 TYPE_MIN_VALUE (type))))
4924 && 0 != (t = fold (build (PLUS_EXPR, type, t,
4925 convert (type, integer_zero_node))))
4926 && host_integerp (t, 1))
4927 count = tree_low_cst (t, 1);
4933 /* Don't waste time with enumeral types with huge values. */
4934 if (! host_integerp (TYPE_MIN_VALUE (type), 0)
4935 || TYPE_MAX_VALUE (type) == 0
4936 || ! host_integerp (TYPE_MAX_VALUE (type), 0))
4939 lastval = minval = tree_low_cst (TYPE_MIN_VALUE (type), 0);
4942 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4944 HOST_WIDE_INT thisval = tree_low_cst (TREE_VALUE (t), 0);
4946 if (*sparseness == 2 || thisval <= lastval)
4948 else if (thisval != minval + count)
4959 #define BITARRAY_TEST(ARRAY, INDEX) \
4960 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4961 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
4962 #define BITARRAY_SET(ARRAY, INDEX) \
4963 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4964 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
4966 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4967 with the case values we have seen, assuming the case expression
4969 SPARSENESS is as determined by all_cases_count.
4971 The time needed is proportional to COUNT, unless
4972 SPARSENESS is 2, in which case quadratic time is needed. */
4975 mark_seen_cases (type, cases_seen, count, sparseness)
4977 unsigned char *cases_seen;
4978 HOST_WIDE_INT count;
4981 tree next_node_to_try = NULL_TREE;
4982 HOST_WIDE_INT next_node_offset = 0;
4984 struct case_node *n, *root = case_stack->data.case_stmt.case_list;
4985 tree val = make_node (INTEGER_CST);
4987 TREE_TYPE (val) = type;
4991 else if (sparseness == 2)
4994 unsigned HOST_WIDE_INT xlo;
4996 /* This less efficient loop is only needed to handle
4997 duplicate case values (multiple enum constants
4998 with the same value). */
4999 TREE_TYPE (val) = TREE_TYPE (root->low);
5000 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
5001 t = TREE_CHAIN (t), xlo++)
5003 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (TREE_VALUE (t));
5004 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (TREE_VALUE (t));
5008 /* Keep going past elements distinctly greater than VAL. */
5009 if (tree_int_cst_lt (val, n->low))
5012 /* or distinctly less than VAL. */
5013 else if (tree_int_cst_lt (n->high, val))
5018 /* We have found a matching range. */
5019 BITARRAY_SET (cases_seen, xlo);
5029 case_stack->data.case_stmt.case_list = root = case_tree2list (root, 0);
5031 for (n = root; n; n = n->right)
5033 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
5034 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
5035 while (! tree_int_cst_lt (n->high, val))
5037 /* Calculate (into xlo) the "offset" of the integer (val).
5038 The element with lowest value has offset 0, the next smallest
5039 element has offset 1, etc. */
5041 unsigned HOST_WIDE_INT xlo;
5045 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
5047 /* The TYPE_VALUES will be in increasing order, so
5048 starting searching where we last ended. */
5049 t = next_node_to_try;
5050 xlo = next_node_offset;
5056 t = TYPE_VALUES (type);
5059 if (tree_int_cst_equal (val, TREE_VALUE (t)))
5061 next_node_to_try = TREE_CHAIN (t);
5062 next_node_offset = xlo + 1;
5067 if (t == next_node_to_try)
5076 t = TYPE_MIN_VALUE (type);
5078 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
5082 add_double (xlo, xhi,
5083 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5087 if (xhi == 0 && xlo < (unsigned HOST_WIDE_INT) count)
5088 BITARRAY_SET (cases_seen, xlo);
5090 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5092 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
5098 /* Given a switch statement with an expression that is an enumeration
5099 type, warn if any of the enumeration type's literals are not
5100 covered by the case expressions of the switch. Also, warn if there
5101 are any extra switch cases that are *not* elements of the
5106 At one stage this function would: ``If all enumeration literals
5107 were covered by the case expressions, turn one of the expressions
5108 into the default expression since it should not be possible to fall
5109 through such a switch.''
5111 That code has since been removed as: ``This optimization is
5112 disabled because it causes valid programs to fail. ANSI C does not
5113 guarantee that an expression with enum type will have a value that
5114 is the same as one of the enumeration literals.'' */
5117 check_for_full_enumeration_handling (type)
5120 struct case_node *n;
5123 /* True iff the selector type is a numbered set mode. */
5126 /* The number of possible selector values. */
5129 /* For each possible selector value. a one iff it has been matched
5130 by a case value alternative. */
5131 unsigned char *cases_seen;
5133 /* The allocated size of cases_seen, in chars. */
5134 HOST_WIDE_INT bytes_needed;
5136 size = all_cases_count (type, &sparseness);
5137 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
5139 if (size > 0 && size < 600000
5140 /* We deliberately use calloc here, not cmalloc, so that we can suppress
5141 this optimization if we don't have enough memory rather than
5142 aborting, as xmalloc would do. */
5144 (unsigned char *) really_call_calloc (bytes_needed, 1)) != NULL)
5147 tree v = TYPE_VALUES (type);
5149 /* The time complexity of this code is normally O(N), where
5150 N being the number of members in the enumerated type.
5151 However, if type is a ENUMERAL_TYPE whose values do not
5152 increase monotonically, O(N*log(N)) time may be needed. */
5154 mark_seen_cases (type, cases_seen, size, sparseness);
5156 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
5157 if (BITARRAY_TEST (cases_seen, i) == 0)
5158 warning ("enumeration value `%s' not handled in switch",
5159 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
5164 /* Now we go the other way around; we warn if there are case
5165 expressions that don't correspond to enumerators. This can
5166 occur since C and C++ don't enforce type-checking of
5167 assignments to enumeration variables. */
5169 if (case_stack->data.case_stmt.case_list
5170 && case_stack->data.case_stmt.case_list->left)
5171 case_stack->data.case_stmt.case_list
5172 = case_tree2list (case_stack->data.case_stmt.case_list, 0);
5173 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
5175 for (chain = TYPE_VALUES (type);
5176 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
5177 chain = TREE_CHAIN (chain))
5182 if (TYPE_NAME (type) == 0)
5183 warning ("case value `%ld' not in enumerated type",
5184 (long) TREE_INT_CST_LOW (n->low));
5186 warning ("case value `%ld' not in enumerated type `%s'",
5187 (long) TREE_INT_CST_LOW (n->low),
5188 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5191 : DECL_NAME (TYPE_NAME (type))));
5193 if (!tree_int_cst_equal (n->low, n->high))
5195 for (chain = TYPE_VALUES (type);
5196 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
5197 chain = TREE_CHAIN (chain))
5202 if (TYPE_NAME (type) == 0)
5203 warning ("case value `%ld' not in enumerated type",
5204 (long) TREE_INT_CST_LOW (n->high));
5206 warning ("case value `%ld' not in enumerated type `%s'",
5207 (long) TREE_INT_CST_LOW (n->high),
5208 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5211 : DECL_NAME (TYPE_NAME (type))));
5217 /* Free CN, and its children. */
5220 free_case_nodes (cn)
5225 free_case_nodes (cn->left);
5226 free_case_nodes (cn->right);
5233 /* Terminate a case (Pascal) or switch (C) statement
5234 in which ORIG_INDEX is the expression to be tested.
5235 If ORIG_TYPE is not NULL, it is the original ORIG_INDEX
5236 type as given in the source before any compiler conversions.
5237 Generate the code to test it and jump to the right place. */
5240 expand_end_case_type (orig_index, orig_type)
5241 tree orig_index, orig_type;
5243 tree minval = NULL_TREE, maxval = NULL_TREE, range = NULL_TREE;
5244 rtx default_label = 0;
5245 struct case_node *n;
5252 rtx before_case, end;
5253 struct nesting *thiscase = case_stack;
5254 tree index_expr, index_type;
5257 /* Don't crash due to previous errors. */
5258 if (thiscase == NULL)
5261 table_label = gen_label_rtx ();
5262 index_expr = thiscase->data.case_stmt.index_expr;
5263 index_type = TREE_TYPE (index_expr);
5264 unsignedp = TREE_UNSIGNED (index_type);
5265 if (orig_type == NULL)
5266 orig_type = TREE_TYPE (orig_index);
5268 do_pending_stack_adjust ();
5270 /* This might get an spurious warning in the presence of a syntax error;
5271 it could be fixed by moving the call to check_seenlabel after the
5272 check for error_mark_node, and copying the code of check_seenlabel that
5273 deals with case_stack->data.case_stmt.line_number_status /
5274 restore_line_number_status in front of the call to end_cleanup_deferral;
5275 However, this might miss some useful warnings in the presence of
5276 non-syntax errors. */
5279 /* An ERROR_MARK occurs for various reasons including invalid data type. */
5280 if (index_type != error_mark_node)
5282 /* If the switch expression was an enumerated type, check that
5283 exactly all enumeration literals are covered by the cases.
5284 The check is made when -Wswitch was specified and there is no
5285 default case, or when -Wswitch-enum was specified. */
5286 if (((warn_switch && !thiscase->data.case_stmt.default_label)
5287 || warn_switch_enum)
5288 && TREE_CODE (orig_type) == ENUMERAL_TYPE
5289 && TREE_CODE (index_expr) != INTEGER_CST)
5290 check_for_full_enumeration_handling (orig_type);
5292 if (warn_switch_default && !thiscase->data.case_stmt.default_label)
5293 warning ("switch missing default case");
5295 /* If we don't have a default-label, create one here,
5296 after the body of the switch. */
5297 if (thiscase->data.case_stmt.default_label == 0)
5299 thiscase->data.case_stmt.default_label
5300 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5301 expand_label (thiscase->data.case_stmt.default_label);
5303 default_label = label_rtx (thiscase->data.case_stmt.default_label);
5305 before_case = get_last_insn ();
5307 if (thiscase->data.case_stmt.case_list
5308 && thiscase->data.case_stmt.case_list->left)
5309 thiscase->data.case_stmt.case_list
5310 = case_tree2list (thiscase->data.case_stmt.case_list, 0);
5312 /* Simplify the case-list before we count it. */
5313 group_case_nodes (thiscase->data.case_stmt.case_list);
5315 /* Get upper and lower bounds of case values.
5316 Also convert all the case values to the index expr's data type. */
5319 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5321 /* Check low and high label values are integers. */
5322 if (TREE_CODE (n->low) != INTEGER_CST)
5324 if (TREE_CODE (n->high) != INTEGER_CST)
5327 n->low = convert (index_type, n->low);
5328 n->high = convert (index_type, n->high);
5330 /* Count the elements and track the largest and smallest
5331 of them (treating them as signed even if they are not). */
5339 if (INT_CST_LT (n->low, minval))
5341 if (INT_CST_LT (maxval, n->high))
5344 /* A range counts double, since it requires two compares. */
5345 if (! tree_int_cst_equal (n->low, n->high))
5349 /* Compute span of values. */
5351 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
5353 end_cleanup_deferral ();
5357 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
5359 emit_jump (default_label);
5362 /* If range of values is much bigger than number of values,
5363 make a sequence of conditional branches instead of a dispatch.
5364 If the switch-index is a constant, do it this way
5365 because we can optimize it. */
5367 else if (count < case_values_threshold ()
5368 || compare_tree_int (range, 10 * count) > 0
5369 /* RANGE may be signed, and really large ranges will show up
5370 as negative numbers. */
5371 || compare_tree_int (range, 0) < 0
5372 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
5375 || TREE_CODE (index_expr) == INTEGER_CST
5376 || (TREE_CODE (index_expr) == COMPOUND_EXPR
5377 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
5379 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5381 /* If the index is a short or char that we do not have
5382 an insn to handle comparisons directly, convert it to
5383 a full integer now, rather than letting each comparison
5384 generate the conversion. */
5386 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
5387 && ! have_insn_for (COMPARE, GET_MODE (index)))
5389 enum machine_mode wider_mode;
5390 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
5391 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
5392 if (have_insn_for (COMPARE, wider_mode))
5394 index = convert_to_mode (wider_mode, index, unsignedp);
5400 do_pending_stack_adjust ();
5402 index = protect_from_queue (index, 0);
5403 if (GET_CODE (index) == MEM)
5404 index = copy_to_reg (index);
5405 if (GET_CODE (index) == CONST_INT
5406 || TREE_CODE (index_expr) == INTEGER_CST)
5408 /* Make a tree node with the proper constant value
5409 if we don't already have one. */
5410 if (TREE_CODE (index_expr) != INTEGER_CST)
5413 = build_int_2 (INTVAL (index),
5414 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
5415 index_expr = convert (index_type, index_expr);
5418 /* For constant index expressions we need only
5419 issue an unconditional branch to the appropriate
5420 target code. The job of removing any unreachable
5421 code is left to the optimisation phase if the
5422 "-O" option is specified. */
5423 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5424 if (! tree_int_cst_lt (index_expr, n->low)
5425 && ! tree_int_cst_lt (n->high, index_expr))
5429 emit_jump (label_rtx (n->code_label));
5431 emit_jump (default_label);
5435 /* If the index expression is not constant we generate
5436 a binary decision tree to select the appropriate
5437 target code. This is done as follows:
5439 The list of cases is rearranged into a binary tree,
5440 nearly optimal assuming equal probability for each case.
5442 The tree is transformed into RTL, eliminating
5443 redundant test conditions at the same time.
5445 If program flow could reach the end of the
5446 decision tree an unconditional jump to the
5447 default code is emitted. */
5450 = (TREE_CODE (orig_type) != ENUMERAL_TYPE
5451 && estimate_case_costs (thiscase->data.case_stmt.case_list));
5452 balance_case_nodes (&thiscase->data.case_stmt.case_list, NULL);
5453 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
5454 default_label, index_type);
5455 emit_jump_if_reachable (default_label);
5460 if (! try_casesi (index_type, index_expr, minval, range,
5461 table_label, default_label))
5463 index_type = thiscase->data.case_stmt.nominal_type;
5465 /* Index jumptables from zero for suitable values of
5466 minval to avoid a subtraction. */
5468 && compare_tree_int (minval, 0) > 0
5469 && compare_tree_int (minval, 3) < 0)
5471 minval = integer_zero_node;
5475 if (! try_tablejump (index_type, index_expr, minval, range,
5476 table_label, default_label))
5480 /* Get table of labels to jump to, in order of case index. */
5482 ncases = tree_low_cst (range, 0) + 1;
5483 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
5484 memset ((char *) labelvec, 0, ncases * sizeof (rtx));
5486 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5488 /* Compute the low and high bounds relative to the minimum
5489 value since that should fit in a HOST_WIDE_INT while the
5490 actual values may not. */
5492 = tree_low_cst (fold (build (MINUS_EXPR, index_type,
5493 n->low, minval)), 1);
5494 HOST_WIDE_INT i_high
5495 = tree_low_cst (fold (build (MINUS_EXPR, index_type,
5496 n->high, minval)), 1);
5499 for (i = i_low; i <= i_high; i ++)
5501 = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label));
5504 /* Fill in the gaps with the default. */
5505 for (i = 0; i < ncases; i++)
5506 if (labelvec[i] == 0)
5507 labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label);
5509 /* Output the table */
5510 emit_label (table_label);
5512 if (CASE_VECTOR_PC_RELATIVE || flag_pic)
5513 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE,
5514 gen_rtx_LABEL_REF (Pmode, table_label),
5515 gen_rtvec_v (ncases, labelvec),
5516 const0_rtx, const0_rtx));
5518 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE,
5519 gen_rtvec_v (ncases, labelvec)));
5521 /* If the case insn drops through the table,
5522 after the table we must jump to the default-label.
5523 Otherwise record no drop-through after the table. */
5524 #ifdef CASE_DROPS_THROUGH
5525 emit_jump (default_label);
5531 before_case = NEXT_INSN (before_case);
5532 end = get_last_insn ();
5533 if (squeeze_notes (&before_case, &end))
5535 reorder_insns (before_case, end,
5536 thiscase->data.case_stmt.start);
5539 end_cleanup_deferral ();
5541 if (thiscase->exit_label)
5542 emit_label (thiscase->exit_label);
5544 free_case_nodes (case_stack->data.case_stmt.case_list);
5545 POPSTACK (case_stack);
5550 /* Convert the tree NODE into a list linked by the right field, with the left
5551 field zeroed. RIGHT is used for recursion; it is a list to be placed
5552 rightmost in the resulting list. */
5554 static struct case_node *
5555 case_tree2list (node, right)
5556 struct case_node *node, *right;
5558 struct case_node *left;
5561 right = case_tree2list (node->right, right);
5563 node->right = right;
5564 if ((left = node->left))
5567 return case_tree2list (left, node);
5573 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5576 do_jump_if_equal (op1, op2, label, unsignedp)
5577 rtx op1, op2, label;
5580 if (GET_CODE (op1) == CONST_INT && GET_CODE (op2) == CONST_INT)
5582 if (INTVAL (op1) == INTVAL (op2))
5586 emit_cmp_and_jump_insns (op1, op2, EQ, NULL_RTX,
5587 (GET_MODE (op1) == VOIDmode
5588 ? GET_MODE (op2) : GET_MODE (op1)),
5592 /* Not all case values are encountered equally. This function
5593 uses a heuristic to weight case labels, in cases where that
5594 looks like a reasonable thing to do.
5596 Right now, all we try to guess is text, and we establish the
5599 chars above space: 16
5608 If we find any cases in the switch that are not either -1 or in the range
5609 of valid ASCII characters, or are control characters other than those
5610 commonly used with "\", don't treat this switch scanning text.
5612 Return 1 if these nodes are suitable for cost estimation, otherwise
5616 estimate_case_costs (node)
5619 tree min_ascii = integer_minus_one_node;
5620 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5624 /* If we haven't already made the cost table, make it now. Note that the
5625 lower bound of the table is -1, not zero. */
5627 if (! cost_table_initialized)
5629 cost_table_initialized = 1;
5631 for (i = 0; i < 128; i++)
5634 COST_TABLE (i) = 16;
5635 else if (ISPUNCT (i))
5637 else if (ISCNTRL (i))
5638 COST_TABLE (i) = -1;
5641 COST_TABLE (' ') = 8;
5642 COST_TABLE ('\t') = 4;
5643 COST_TABLE ('\0') = 4;
5644 COST_TABLE ('\n') = 2;
5645 COST_TABLE ('\f') = 1;
5646 COST_TABLE ('\v') = 1;
5647 COST_TABLE ('\b') = 1;
5650 /* See if all the case expressions look like text. It is text if the
5651 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5652 as signed arithmetic since we don't want to ever access cost_table with a
5653 value less than -1. Also check that none of the constants in a range
5654 are strange control characters. */
5656 for (n = node; n; n = n->right)
5658 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5661 for (i = (HOST_WIDE_INT) TREE_INT_CST_LOW (n->low);
5662 i <= (HOST_WIDE_INT) TREE_INT_CST_LOW (n->high); i++)
5663 if (COST_TABLE (i) < 0)
5667 /* All interesting values are within the range of interesting
5668 ASCII characters. */
5672 /* Scan an ordered list of case nodes
5673 combining those with consecutive values or ranges.
5675 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5678 group_case_nodes (head)
5681 case_node_ptr node = head;
5685 rtx lb = next_real_insn (label_rtx (node->code_label));
5687 case_node_ptr np = node;
5689 /* Try to group the successors of NODE with NODE. */
5690 while (((np = np->right) != 0)
5691 /* Do they jump to the same place? */
5692 && ((lb2 = next_real_insn (label_rtx (np->code_label))) == lb
5693 || (lb != 0 && lb2 != 0
5694 && simplejump_p (lb)
5695 && simplejump_p (lb2)
5696 && rtx_equal_p (SET_SRC (PATTERN (lb)),
5697 SET_SRC (PATTERN (lb2)))))
5698 /* Are their ranges consecutive? */
5699 && tree_int_cst_equal (np->low,
5700 fold (build (PLUS_EXPR,
5701 TREE_TYPE (node->high),
5704 /* An overflow is not consecutive. */
5705 && tree_int_cst_lt (node->high,
5706 fold (build (PLUS_EXPR,
5707 TREE_TYPE (node->high),
5709 integer_one_node))))
5711 node->high = np->high;
5713 /* NP is the first node after NODE which can't be grouped with it.
5714 Delete the nodes in between, and move on to that node. */
5720 /* Take an ordered list of case nodes
5721 and transform them into a near optimal binary tree,
5722 on the assumption that any target code selection value is as
5723 likely as any other.
5725 The transformation is performed by splitting the ordered
5726 list into two equal sections plus a pivot. The parts are
5727 then attached to the pivot as left and right branches. Each
5728 branch is then transformed recursively. */
5731 balance_case_nodes (head, parent)
5732 case_node_ptr *head;
5733 case_node_ptr parent;
5746 /* Count the number of entries on branch. Also count the ranges. */
5750 if (!tree_int_cst_equal (np->low, np->high))
5754 cost += COST_TABLE (TREE_INT_CST_LOW (np->high));
5758 cost += COST_TABLE (TREE_INT_CST_LOW (np->low));
5766 /* Split this list if it is long enough for that to help. */
5771 /* Find the place in the list that bisects the list's total cost,
5772 Here I gets half the total cost. */
5777 /* Skip nodes while their cost does not reach that amount. */
5778 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5779 i -= COST_TABLE (TREE_INT_CST_LOW ((*npp)->high));
5780 i -= COST_TABLE (TREE_INT_CST_LOW ((*npp)->low));
5783 npp = &(*npp)->right;
5788 /* Leave this branch lopsided, but optimize left-hand
5789 side and fill in `parent' fields for right-hand side. */
5791 np->parent = parent;
5792 balance_case_nodes (&np->left, np);
5793 for (; np->right; np = np->right)
5794 np->right->parent = np;
5798 /* If there are just three nodes, split at the middle one. */
5800 npp = &(*npp)->right;
5803 /* Find the place in the list that bisects the list's total cost,
5804 where ranges count as 2.
5805 Here I gets half the total cost. */
5806 i = (i + ranges + 1) / 2;
5809 /* Skip nodes while their cost does not reach that amount. */
5810 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5815 npp = &(*npp)->right;
5820 np->parent = parent;
5823 /* Optimize each of the two split parts. */
5824 balance_case_nodes (&np->left, np);
5825 balance_case_nodes (&np->right, np);
5829 /* Else leave this branch as one level,
5830 but fill in `parent' fields. */
5832 np->parent = parent;
5833 for (; np->right; np = np->right)
5834 np->right->parent = np;
5839 /* Search the parent sections of the case node tree
5840 to see if a test for the lower bound of NODE would be redundant.
5841 INDEX_TYPE is the type of the index expression.
5843 The instructions to generate the case decision tree are
5844 output in the same order as nodes are processed so it is
5845 known that if a parent node checks the range of the current
5846 node minus one that the current node is bounded at its lower
5847 span. Thus the test would be redundant. */
5850 node_has_low_bound (node, index_type)
5855 case_node_ptr pnode;
5857 /* If the lower bound of this node is the lowest value in the index type,
5858 we need not test it. */
5860 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
5863 /* If this node has a left branch, the value at the left must be less
5864 than that at this node, so it cannot be bounded at the bottom and
5865 we need not bother testing any further. */
5870 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
5871 node->low, integer_one_node));
5873 /* If the subtraction above overflowed, we can't verify anything.
5874 Otherwise, look for a parent that tests our value - 1. */
5876 if (! tree_int_cst_lt (low_minus_one, node->low))
5879 for (pnode = node->parent; pnode; pnode = pnode->parent)
5880 if (tree_int_cst_equal (low_minus_one, pnode->high))
5886 /* Search the parent sections of the case node tree
5887 to see if a test for the upper bound of NODE would be redundant.
5888 INDEX_TYPE is the type of the index expression.
5890 The instructions to generate the case decision tree are
5891 output in the same order as nodes are processed so it is
5892 known that if a parent node checks the range of the current
5893 node plus one that the current node is bounded at its upper
5894 span. Thus the test would be redundant. */
5897 node_has_high_bound (node, index_type)
5902 case_node_ptr pnode;
5904 /* If there is no upper bound, obviously no test is needed. */
5906 if (TYPE_MAX_VALUE (index_type) == NULL)
5909 /* If the upper bound of this node is the highest value in the type
5910 of the index expression, we need not test against it. */
5912 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
5915 /* If this node has a right branch, the value at the right must be greater
5916 than that at this node, so it cannot be bounded at the top and
5917 we need not bother testing any further. */
5922 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
5923 node->high, integer_one_node));
5925 /* If the addition above overflowed, we can't verify anything.
5926 Otherwise, look for a parent that tests our value + 1. */
5928 if (! tree_int_cst_lt (node->high, high_plus_one))
5931 for (pnode = node->parent; pnode; pnode = pnode->parent)
5932 if (tree_int_cst_equal (high_plus_one, pnode->low))
5938 /* Search the parent sections of the
5939 case node tree to see if both tests for the upper and lower
5940 bounds of NODE would be redundant. */
5943 node_is_bounded (node, index_type)
5947 return (node_has_low_bound (node, index_type)
5948 && node_has_high_bound (node, index_type));
5951 /* Emit an unconditional jump to LABEL unless it would be dead code. */
5954 emit_jump_if_reachable (label)
5957 if (GET_CODE (get_last_insn ()) != BARRIER)
5961 /* Emit step-by-step code to select a case for the value of INDEX.
5962 The thus generated decision tree follows the form of the
5963 case-node binary tree NODE, whose nodes represent test conditions.
5964 INDEX_TYPE is the type of the index of the switch.
5966 Care is taken to prune redundant tests from the decision tree
5967 by detecting any boundary conditions already checked by
5968 emitted rtx. (See node_has_high_bound, node_has_low_bound
5969 and node_is_bounded, above.)
5971 Where the test conditions can be shown to be redundant we emit
5972 an unconditional jump to the target code. As a further
5973 optimization, the subordinates of a tree node are examined to
5974 check for bounded nodes. In this case conditional and/or
5975 unconditional jumps as a result of the boundary check for the
5976 current node are arranged to target the subordinates associated
5977 code for out of bound conditions on the current node.
5979 We can assume that when control reaches the code generated here,
5980 the index value has already been compared with the parents
5981 of this node, and determined to be on the same side of each parent
5982 as this node is. Thus, if this node tests for the value 51,
5983 and a parent tested for 52, we don't need to consider
5984 the possibility of a value greater than 51. If another parent
5985 tests for the value 50, then this node need not test anything. */
5988 emit_case_nodes (index, node, default_label, index_type)
5994 /* If INDEX has an unsigned type, we must make unsigned branches. */
5995 int unsignedp = TREE_UNSIGNED (index_type);
5996 enum machine_mode mode = GET_MODE (index);
5997 enum machine_mode imode = TYPE_MODE (index_type);
5999 /* See if our parents have already tested everything for us.
6000 If they have, emit an unconditional jump for this node. */
6001 if (node_is_bounded (node, index_type))
6002 emit_jump (label_rtx (node->code_label));
6004 else if (tree_int_cst_equal (node->low, node->high))
6006 /* Node is single valued. First see if the index expression matches
6007 this node and then check our children, if any. */
6009 do_jump_if_equal (index,
6010 convert_modes (mode, imode,
6011 expand_expr (node->low, NULL_RTX,
6014 label_rtx (node->code_label), unsignedp);
6016 if (node->right != 0 && node->left != 0)
6018 /* This node has children on both sides.
6019 Dispatch to one side or the other
6020 by comparing the index value with this node's value.
6021 If one subtree is bounded, check that one first,
6022 so we can avoid real branches in the tree. */
6024 if (node_is_bounded (node->right, index_type))
6026 emit_cmp_and_jump_insns (index,
6029 expand_expr (node->high, NULL_RTX,
6032 GT, NULL_RTX, mode, unsignedp,
6033 label_rtx (node->right->code_label));
6034 emit_case_nodes (index, node->left, default_label, index_type);
6037 else if (node_is_bounded (node->left, index_type))
6039 emit_cmp_and_jump_insns (index,
6042 expand_expr (node->high, NULL_RTX,
6045 LT, NULL_RTX, mode, unsignedp,
6046 label_rtx (node->left->code_label));
6047 emit_case_nodes (index, node->right, default_label, index_type);
6052 /* Neither node is bounded. First distinguish the two sides;
6053 then emit the code for one side at a time. */
6055 tree test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6057 /* See if the value is on the right. */
6058 emit_cmp_and_jump_insns (index,
6061 expand_expr (node->high, NULL_RTX,
6064 GT, NULL_RTX, mode, unsignedp,
6065 label_rtx (test_label));
6067 /* Value must be on the left.
6068 Handle the left-hand subtree. */
6069 emit_case_nodes (index, node->left, default_label, index_type);
6070 /* If left-hand subtree does nothing,
6072 emit_jump_if_reachable (default_label);
6074 /* Code branches here for the right-hand subtree. */
6075 expand_label (test_label);
6076 emit_case_nodes (index, node->right, default_label, index_type);
6080 else if (node->right != 0 && node->left == 0)
6082 /* Here we have a right child but no left so we issue conditional
6083 branch to default and process the right child.
6085 Omit the conditional branch to default if we it avoid only one
6086 right child; it costs too much space to save so little time. */
6088 if (node->right->right || node->right->left
6089 || !tree_int_cst_equal (node->right->low, node->right->high))
6091 if (!node_has_low_bound (node, index_type))
6093 emit_cmp_and_jump_insns (index,
6096 expand_expr (node->high, NULL_RTX,
6099 LT, NULL_RTX, mode, unsignedp,
6103 emit_case_nodes (index, node->right, default_label, index_type);
6106 /* We cannot process node->right normally
6107 since we haven't ruled out the numbers less than
6108 this node's value. So handle node->right explicitly. */
6109 do_jump_if_equal (index,
6112 expand_expr (node->right->low, NULL_RTX,
6115 label_rtx (node->right->code_label), unsignedp);
6118 else if (node->right == 0 && node->left != 0)
6120 /* Just one subtree, on the left. */
6121 if (node->left->left || node->left->right
6122 || !tree_int_cst_equal (node->left->low, node->left->high))
6124 if (!node_has_high_bound (node, index_type))
6126 emit_cmp_and_jump_insns (index,
6129 expand_expr (node->high, NULL_RTX,
6132 GT, NULL_RTX, mode, unsignedp,
6136 emit_case_nodes (index, node->left, default_label, index_type);
6139 /* We cannot process node->left normally
6140 since we haven't ruled out the numbers less than
6141 this node's value. So handle node->left explicitly. */
6142 do_jump_if_equal (index,
6145 expand_expr (node->left->low, NULL_RTX,
6148 label_rtx (node->left->code_label), unsignedp);
6153 /* Node is a range. These cases are very similar to those for a single
6154 value, except that we do not start by testing whether this node
6155 is the one to branch to. */
6157 if (node->right != 0 && node->left != 0)
6159 /* Node has subtrees on both sides.
6160 If the right-hand subtree is bounded,
6161 test for it first, since we can go straight there.
6162 Otherwise, we need to make a branch in the control structure,
6163 then handle the two subtrees. */
6164 tree test_label = 0;
6166 if (node_is_bounded (node->right, index_type))
6167 /* Right hand node is fully bounded so we can eliminate any
6168 testing and branch directly to the target code. */
6169 emit_cmp_and_jump_insns (index,
6172 expand_expr (node->high, NULL_RTX,
6175 GT, NULL_RTX, mode, unsignedp,
6176 label_rtx (node->right->code_label));
6179 /* Right hand node requires testing.
6180 Branch to a label where we will handle it later. */
6182 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6183 emit_cmp_and_jump_insns (index,
6186 expand_expr (node->high, NULL_RTX,
6189 GT, NULL_RTX, mode, unsignedp,
6190 label_rtx (test_label));
6193 /* Value belongs to this node or to the left-hand subtree. */
6195 emit_cmp_and_jump_insns (index,
6198 expand_expr (node->low, NULL_RTX,
6201 GE, NULL_RTX, mode, unsignedp,
6202 label_rtx (node->code_label));
6204 /* Handle the left-hand subtree. */
6205 emit_case_nodes (index, node->left, default_label, index_type);
6207 /* If right node had to be handled later, do that now. */
6211 /* If the left-hand subtree fell through,
6212 don't let it fall into the right-hand subtree. */
6213 emit_jump_if_reachable (default_label);
6215 expand_label (test_label);
6216 emit_case_nodes (index, node->right, default_label, index_type);
6220 else if (node->right != 0 && node->left == 0)
6222 /* Deal with values to the left of this node,
6223 if they are possible. */
6224 if (!node_has_low_bound (node, index_type))
6226 emit_cmp_and_jump_insns (index,
6229 expand_expr (node->low, NULL_RTX,
6232 LT, NULL_RTX, mode, unsignedp,
6236 /* Value belongs to this node or to the right-hand subtree. */
6238 emit_cmp_and_jump_insns (index,
6241 expand_expr (node->high, NULL_RTX,
6244 LE, NULL_RTX, mode, unsignedp,
6245 label_rtx (node->code_label));
6247 emit_case_nodes (index, node->right, default_label, index_type);
6250 else if (node->right == 0 && node->left != 0)
6252 /* Deal with values to the right of this node,
6253 if they are possible. */
6254 if (!node_has_high_bound (node, index_type))
6256 emit_cmp_and_jump_insns (index,
6259 expand_expr (node->high, NULL_RTX,
6262 GT, NULL_RTX, mode, unsignedp,
6266 /* Value belongs to this node or to the left-hand subtree. */
6268 emit_cmp_and_jump_insns (index,
6271 expand_expr (node->low, NULL_RTX,
6274 GE, NULL_RTX, mode, unsignedp,
6275 label_rtx (node->code_label));
6277 emit_case_nodes (index, node->left, default_label, index_type);
6282 /* Node has no children so we check low and high bounds to remove
6283 redundant tests. Only one of the bounds can exist,
6284 since otherwise this node is bounded--a case tested already. */
6285 int high_bound = node_has_high_bound (node, index_type);
6286 int low_bound = node_has_low_bound (node, index_type);
6288 if (!high_bound && low_bound)
6290 emit_cmp_and_jump_insns (index,
6293 expand_expr (node->high, NULL_RTX,
6296 GT, NULL_RTX, mode, unsignedp,
6300 else if (!low_bound && high_bound)
6302 emit_cmp_and_jump_insns (index,
6305 expand_expr (node->low, NULL_RTX,
6308 LT, NULL_RTX, mode, unsignedp,
6311 else if (!low_bound && !high_bound)
6313 /* Widen LOW and HIGH to the same width as INDEX. */
6314 tree type = (*lang_hooks.types.type_for_mode) (mode, unsignedp);
6315 tree low = build1 (CONVERT_EXPR, type, node->low);
6316 tree high = build1 (CONVERT_EXPR, type, node->high);
6317 rtx low_rtx, new_index, new_bound;
6319 /* Instead of doing two branches, emit one unsigned branch for
6320 (index-low) > (high-low). */
6321 low_rtx = expand_expr (low, NULL_RTX, mode, 0);
6322 new_index = expand_simple_binop (mode, MINUS, index, low_rtx,
6323 NULL_RTX, unsignedp,
6325 new_bound = expand_expr (fold (build (MINUS_EXPR, type,
6329 emit_cmp_and_jump_insns (new_index, new_bound, GT, NULL_RTX,
6330 mode, 1, default_label);
6333 emit_jump (label_rtx (node->code_label));