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, 1998, 3 1999, 2000 Free Software Foundation, Inc. 4 5This file is part of GNU CC. 6 7GNU CC is free software; you can redistribute it and/or modify 8it under the terms of the GNU General Public License as published by 9the Free Software Foundation; either version 2, or (at your option) 10any later version. 11 12GNU CC is distributed in the hope that it will be useful, 13but WITHOUT ANY WARRANTY; without even the implied warranty of 14MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15GNU General Public License for more details. 16 17You should have received a copy of the GNU General Public License 18along with GNU CC; see the file COPYING. If not, write to 19the Free Software Foundation, 59 Temple Place - Suite 330, 20Boston, MA 02111-1307, USA. */ 21 22 23/* This file handles the generation of rtl code from tree structure 24 above the level of expressions, using subroutines in exp*.c and emit-rtl.c. 25 It also creates the rtl expressions for parameters and auto variables 26 and has full responsibility for allocating stack slots. 27 28 The functions whose names start with `expand_' are called by the 29 parser to generate RTL instructions for various kinds of constructs. 30 31 Some control and binding constructs require calling several such 32 functions at different times. For example, a simple if-then 33 is expanded by calling `expand_start_cond' (with the condition-expression 34 as argument) before parsing the then-clause and calling `expand_end_cond' 35 after parsing the then-clause. */ 36 37#include "config.h" 38#include "system.h" 39 40#include "rtl.h" 41#include "tree.h" 42#include "flags.h" 43#include "except.h" 44#include "function.h" 45#include "insn-flags.h" 46#include "insn-config.h" 47#include "insn-codes.h" 48#include "expr.h" 49#include "hard-reg-set.h" 50#include "obstack.h" 51#include "loop.h" 52#include "recog.h" 53#include "machmode.h" 54#include "toplev.h" 55#include "output.h" 56 57#define obstack_chunk_alloc xmalloc 58#define obstack_chunk_free free 59struct obstack stmt_obstack; 60 61/* Assume that case vectors are not pc-relative. */ 62#ifndef CASE_VECTOR_PC_RELATIVE 63#define CASE_VECTOR_PC_RELATIVE 0 64#endif 65 66/* Filename and line number of last line-number note, 67 whether we actually emitted it or not. */ 68char *emit_filename; 69int emit_lineno; 70 71/* Nonzero if within a ({...}) grouping, in which case we must 72 always compute a value for each expr-stmt in case it is the last one. */ 73 74int expr_stmts_for_value; 75 76/* Each time we expand an expression-statement, 77 record the expr's type and its RTL value here. */ 78 79static tree last_expr_type; 80static rtx last_expr_value; 81 82/* Each time we expand the end of a binding contour (in `expand_end_bindings') 83 and we emit a new NOTE_INSN_BLOCK_END note, we save a pointer to it here. 84 This is used by the `remember_end_note' function to record the endpoint 85 of each generated block in its associated BLOCK node. */ 86 87static rtx last_block_end_note; 88 89/* Number of binding contours started so far in this function. */ 90 91int block_start_count; 92 93/* Functions and data structures for expanding case statements. */ 94 95/* Case label structure, used to hold info on labels within case 96 statements. We handle "range" labels; for a single-value label 97 as in C, the high and low limits are the same. 98 99 An AVL tree of case nodes is initially created, and later transformed 100 to a list linked via the RIGHT fields in the nodes. Nodes with 101 higher case values are later in the list. 102 103 Switch statements can be output in one of two forms. A branch table 104 is used if there are more than a few labels and the labels are dense 105 within the range between the smallest and largest case value. If a 106 branch table is used, no further manipulations are done with the case 107 node chain. 108 109 The alternative to the use of a branch table is to generate a series 110 of compare and jump insns. When that is done, we use the LEFT, RIGHT, 111 and PARENT fields to hold a binary tree. Initially the tree is 112 totally unbalanced, with everything on the right. We balance the tree 113 with nodes on the left having lower case values than the parent 114 and nodes on the right having higher values. We then output the tree 115 in order. */ 116 117struct case_node 118{ 119 struct case_node *left; /* Left son in binary tree */ 120 struct case_node *right; /* Right son in binary tree; also node chain */ 121 struct case_node *parent; /* Parent of node in binary tree */ 122 tree low; /* Lowest index value for this label */ 123 tree high; /* Highest index value for this label */ 124 tree code_label; /* Label to jump to when node matches */ 125 int balance; 126}; 127 128typedef struct case_node case_node; 129typedef struct case_node *case_node_ptr; 130 131/* These are used by estimate_case_costs and balance_case_nodes. */ 132 133/* This must be a signed type, and non-ANSI compilers lack signed char. */ 134static short *cost_table; 135static int use_cost_table; 136 137/* Stack of control and binding constructs we are currently inside. 138 139 These constructs begin when you call `expand_start_WHATEVER' 140 and end when you call `expand_end_WHATEVER'. This stack records 141 info about how the construct began that tells the end-function 142 what to do. It also may provide information about the construct 143 to alter the behavior of other constructs within the body. 144 For example, they may affect the behavior of C `break' and `continue'. 145 146 Each construct gets one `struct nesting' object. 147 All of these objects are chained through the `all' field. 148 `nesting_stack' points to the first object (innermost construct). 149 The position of an entry on `nesting_stack' is in its `depth' field. 150 151 Each type of construct has its own individual stack. 152 For example, loops have `loop_stack'. Each object points to the 153 next object of the same type through the `next' field. 154 155 Some constructs are visible to `break' exit-statements and others 156 are not. Which constructs are visible depends on the language. 157 Therefore, the data structure allows each construct to be visible 158 or not, according to the args given when the construct is started. 159 The construct is visible if the `exit_label' field is non-null. 160 In that case, the value should be a CODE_LABEL rtx. */ 161 162struct nesting 163{ 164 struct nesting *all; 165 struct nesting *next; 166 int depth; 167 rtx exit_label; 168 union 169 { 170 /* For conds (if-then and if-then-else statements). */ 171 struct 172 { 173 /* Label for the end of the if construct. 174 There is none if EXITFLAG was not set 175 and no `else' has been seen yet. */ 176 rtx endif_label; 177 /* Label for the end of this alternative. 178 This may be the end of the if or the next else/elseif. */ 179 rtx next_label; 180 } cond; 181 /* For loops. */ 182 struct 183 { 184 /* Label at the top of the loop; place to loop back to. */ 185 rtx start_label; 186 /* Label at the end of the whole construct. */ 187 rtx end_label; 188 /* Label before a jump that branches to the end of the whole 189 construct. This is where destructors go if any. */ 190 rtx alt_end_label; 191 /* Label for `continue' statement to jump to; 192 this is in front of the stepper of the loop. */ 193 rtx continue_label; 194 } loop; 195 /* For variable binding contours. */ 196 struct 197 { 198 /* Sequence number of this binding contour within the function, 199 in order of entry. */ 200 int block_start_count; 201 /* Nonzero => value to restore stack to on exit. */ 202 rtx stack_level; 203 /* The NOTE that starts this contour. 204 Used by expand_goto to check whether the destination 205 is within each contour or not. */ 206 rtx first_insn; 207 /* Innermost containing binding contour that has a stack level. */ 208 struct nesting *innermost_stack_block; 209 /* List of cleanups to be run on exit from this contour. 210 This is a list of expressions to be evaluated. 211 The TREE_PURPOSE of each link is the ..._DECL node 212 which the cleanup pertains to. */ 213 tree cleanups; 214 /* List of cleanup-lists of blocks containing this block, 215 as they were at the locus where this block appears. 216 There is an element for each containing block, 217 ordered innermost containing block first. 218 The tail of this list can be 0, 219 if all remaining elements would be empty lists. 220 The element's TREE_VALUE is the cleanup-list of that block, 221 which may be null. */ 222 tree outer_cleanups; 223 /* Chain of labels defined inside this binding contour. 224 For contours that have stack levels or cleanups. */ 225 struct label_chain *label_chain; 226 /* Number of function calls seen, as of start of this block. */ 227 int function_call_count; 228 /* Nonzero if this is associated with a EH region. */ 229 int exception_region; 230 /* The saved target_temp_slot_level from our outer block. 231 We may reset target_temp_slot_level to be the level of 232 this block, if that is done, target_temp_slot_level 233 reverts to the saved target_temp_slot_level at the very 234 end of the block. */ 235 int target_temp_slot_level; 236 /* True if we are currently emitting insns in an area of 237 output code that is controlled by a conditional 238 expression. This is used by the cleanup handling code to 239 generate conditional cleanup actions. */ 240 int conditional_code; 241 /* A place to move the start of the exception region for any 242 of the conditional cleanups, must be at the end or after 243 the start of the last unconditional cleanup, and before any 244 conditional branch points. */ 245 rtx last_unconditional_cleanup; 246 /* When in a conditional context, this is the specific 247 cleanup list associated with last_unconditional_cleanup, 248 where we place the conditionalized cleanups. */ 249 tree *cleanup_ptr; 250 } block; 251 /* For switch (C) or case (Pascal) statements, 252 and also for dummies (see `expand_start_case_dummy'). */ 253 struct 254 { 255 /* The insn after which the case dispatch should finally 256 be emitted. Zero for a dummy. */ 257 rtx start; 258 /* A list of case labels; it is first built as an AVL tree. 259 During expand_end_case, this is converted to a list, and may be 260 rearranged into a nearly balanced binary tree. */ 261 struct case_node *case_list; 262 /* Label to jump to if no case matches. */ 263 tree default_label; 264 /* The expression to be dispatched on. */ 265 tree index_expr; 266 /* Type that INDEX_EXPR should be converted to. */ 267 tree nominal_type; 268 /* Number of range exprs in case statement. */ 269 int num_ranges; 270 /* Name of this kind of statement, for warnings. */ 271 const char *printname; 272 /* Used to save no_line_numbers till we see the first case label. 273 We set this to -1 when we see the first case label in this 274 case statement. */ 275 int line_number_status; 276 } case_stmt; 277 } data; 278}; 279 280/* Chain of all pending binding contours. */ 281struct nesting *block_stack; 282 283/* If any new stacks are added here, add them to POPSTACKS too. */ 284 285/* Chain of all pending binding contours that restore stack levels 286 or have cleanups. */ 287struct nesting *stack_block_stack; 288 289/* Chain of all pending conditional statements. */ 290struct nesting *cond_stack; 291 292/* Chain of all pending loops. */ 293struct nesting *loop_stack; 294 295/* Chain of all pending case or switch statements. */ 296struct nesting *case_stack; 297 298/* Separate chain including all of the above, 299 chained through the `all' field. */ 300struct nesting *nesting_stack; 301 302/* Number of entries on nesting_stack now. */ 303int nesting_depth; 304 305/* Allocate and return a new `struct nesting'. */ 306 307#define ALLOC_NESTING() \ 308 (struct nesting *) obstack_alloc (&stmt_obstack, sizeof (struct nesting)) 309 310/* Pop the nesting stack element by element until we pop off 311 the element which is at the top of STACK. 312 Update all the other stacks, popping off elements from them 313 as we pop them from nesting_stack. */ 314 315#define POPSTACK(STACK) \ 316do { struct nesting *target = STACK; \ 317 struct nesting *this; \ 318 do { this = nesting_stack; \ 319 if (loop_stack == this) \ 320 loop_stack = loop_stack->next; \ 321 if (cond_stack == this) \ 322 cond_stack = cond_stack->next; \ 323 if (block_stack == this) \ 324 block_stack = block_stack->next; \ 325 if (stack_block_stack == this) \ 326 stack_block_stack = stack_block_stack->next; \ 327 if (case_stack == this) \ 328 case_stack = case_stack->next; \ 329 nesting_depth = nesting_stack->depth - 1; \ 330 nesting_stack = this->all; \ 331 obstack_free (&stmt_obstack, this); } \ 332 while (this != target); } while (0) 333 334/* In some cases it is impossible to generate code for a forward goto 335 until the label definition is seen. This happens when it may be necessary 336 for the goto to reset the stack pointer: we don't yet know how to do that. 337 So expand_goto puts an entry on this fixup list. 338 Each time a binding contour that resets the stack is exited, 339 we check each fixup. 340 If the target label has now been defined, we can insert the proper code. */ 341 342struct goto_fixup 343{ 344 /* Points to following fixup. */ 345 struct goto_fixup *next; 346 /* Points to the insn before the jump insn. 347 If more code must be inserted, it goes after this insn. */ 348 rtx before_jump; 349 /* The LABEL_DECL that this jump is jumping to, or 0 350 for break, continue or return. */ 351 tree target; 352 /* The BLOCK for the place where this goto was found. */ 353 tree context; 354 /* The CODE_LABEL rtx that this is jumping to. */ 355 rtx target_rtl; 356 /* Number of binding contours started in current function 357 before the label reference. */ 358 int block_start_count; 359 /* The outermost stack level that should be restored for this jump. 360 Each time a binding contour that resets the stack is exited, 361 if the target label is *not* yet defined, this slot is updated. */ 362 rtx stack_level; 363 /* List of lists of cleanup expressions to be run by this goto. 364 There is one element for each block that this goto is within. 365 The tail of this list can be 0, 366 if all remaining elements would be empty. 367 The TREE_VALUE contains the cleanup list of that block as of the 368 time this goto was seen. 369 The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */ 370 tree cleanup_list_list; 371}; 372 373static struct goto_fixup *goto_fixup_chain; 374 375/* Within any binding contour that must restore a stack level, 376 all labels are recorded with a chain of these structures. */ 377 378struct label_chain 379{ 380 /* Points to following fixup. */ 381 struct label_chain *next; 382 tree label; 383}; 384 385 386/* Non-zero if we are using EH to handle cleanus. */ 387static int using_eh_for_cleanups_p = 0; 388 389 390static int n_occurrences PROTO((int, const char *)); 391static void expand_goto_internal PROTO((tree, rtx, rtx)); 392static int expand_fixup PROTO((tree, rtx, rtx)); 393static rtx expand_nl_handler_label PROTO((rtx, rtx)); 394static void expand_nl_goto_receiver PROTO((void)); 395static void expand_nl_goto_receivers PROTO((struct nesting *)); 396static void fixup_gotos PROTO((struct nesting *, rtx, tree, 397 rtx, int)); 398static void expand_null_return_1 PROTO((rtx, int)); 399static void expand_value_return PROTO((rtx)); 400static int tail_recursion_args PROTO((tree, tree)); 401static void expand_cleanups PROTO((tree, tree, int, int)); 402static void check_seenlabel PROTO((void)); 403static void do_jump_if_equal PROTO((rtx, rtx, rtx, int)); 404static int estimate_case_costs PROTO((case_node_ptr)); 405static void group_case_nodes PROTO((case_node_ptr)); 406static void balance_case_nodes PROTO((case_node_ptr *, 407 case_node_ptr)); 408static int node_has_low_bound PROTO((case_node_ptr, tree)); 409static int node_has_high_bound PROTO((case_node_ptr, tree)); 410static int node_is_bounded PROTO((case_node_ptr, tree)); 411static void emit_jump_if_reachable PROTO((rtx)); 412static void emit_case_nodes PROTO((rtx, case_node_ptr, rtx, tree)); 413static int add_case_node PROTO((tree, tree, tree, tree *)); 414static struct case_node *case_tree2list PROTO((case_node *, case_node *)); 415 416void 417using_eh_for_cleanups () 418{ 419 using_eh_for_cleanups_p = 1; 420} 421 422void 423init_stmt () 424{ 425 gcc_obstack_init (&stmt_obstack); 426 init_eh (); 427} 428 429void 430init_stmt_for_function () 431{ 432 /* We are not currently within any block, conditional, loop or case. */ 433 block_stack = 0; 434 stack_block_stack = 0; 435 loop_stack = 0; 436 case_stack = 0; 437 cond_stack = 0; 438 nesting_stack = 0; 439 nesting_depth = 0; 440 441 block_start_count = 0; 442 443 /* No gotos have been expanded yet. */ 444 goto_fixup_chain = 0; 445 446 /* We are not processing a ({...}) grouping. */ 447 expr_stmts_for_value = 0; 448 last_expr_type = 0; 449 450 init_eh_for_function (); 451} 452 453void 454save_stmt_status (p) 455 struct function *p; 456{ 457 p->block_stack = block_stack; 458 p->stack_block_stack = stack_block_stack; 459 p->cond_stack = cond_stack; 460 p->loop_stack = loop_stack; 461 p->case_stack = case_stack; 462 p->nesting_stack = nesting_stack; 463 p->nesting_depth = nesting_depth; 464 p->block_start_count = block_start_count; 465 p->last_expr_type = last_expr_type; 466 p->last_expr_value = last_expr_value; 467 p->expr_stmts_for_value = expr_stmts_for_value; 468 p->emit_filename = emit_filename; 469 p->emit_lineno = emit_lineno; 470 p->goto_fixup_chain = goto_fixup_chain; 471 save_eh_status (p); 472} 473 474void 475restore_stmt_status (p) 476 struct function *p; 477{ 478 block_stack = p->block_stack; 479 stack_block_stack = p->stack_block_stack; 480 cond_stack = p->cond_stack; 481 loop_stack = p->loop_stack; 482 case_stack = p->case_stack; 483 nesting_stack = p->nesting_stack; 484 nesting_depth = p->nesting_depth; 485 block_start_count = p->block_start_count; 486 last_expr_type = p->last_expr_type; 487 last_expr_value = p->last_expr_value; 488 expr_stmts_for_value = p->expr_stmts_for_value; 489 emit_filename = p->emit_filename; 490 emit_lineno = p->emit_lineno; 491 goto_fixup_chain = p->goto_fixup_chain; 492 restore_eh_status (p); 493} 494 495/* Emit a no-op instruction. */ 496 497void 498emit_nop () 499{ 500 rtx last_insn; 501 502 last_insn = get_last_insn (); 503 if (!optimize 504 && (GET_CODE (last_insn) == CODE_LABEL 505 || (GET_CODE (last_insn) == NOTE 506 && prev_real_insn (last_insn) == 0))) 507 emit_insn (gen_nop ()); 508} 509 510/* Return the rtx-label that corresponds to a LABEL_DECL, 511 creating it if necessary. */ 512 513rtx 514label_rtx (label) 515 tree label; 516{ 517 if (TREE_CODE (label) != LABEL_DECL) 518 abort (); 519 520 if (DECL_RTL (label)) 521 return DECL_RTL (label); 522 523 return DECL_RTL (label) = gen_label_rtx (); 524} 525 526/* Add an unconditional jump to LABEL as the next sequential instruction. */ 527 528void 529emit_jump (label) 530 rtx label; 531{ 532 do_pending_stack_adjust (); 533 emit_jump_insn (gen_jump (label)); 534 emit_barrier (); 535} 536 537/* Emit code to jump to the address 538 specified by the pointer expression EXP. */ 539 540void 541expand_computed_goto (exp) 542 tree exp; 543{ 544 rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0); 545 546#ifdef POINTERS_EXTEND_UNSIGNED 547 x = convert_memory_address (Pmode, x); 548#endif 549 550 emit_queue (); 551 /* Be sure the function is executable. */ 552 if (current_function_check_memory_usage) 553 emit_library_call (chkr_check_exec_libfunc, 1, 554 VOIDmode, 1, x, ptr_mode); 555 556 do_pending_stack_adjust (); 557 emit_indirect_jump (x); 558 559 current_function_has_computed_jump = 1; 560} 561 562/* Handle goto statements and the labels that they can go to. */ 563 564/* Specify the location in the RTL code of a label LABEL, 565 which is a LABEL_DECL tree node. 566 567 This is used for the kind of label that the user can jump to with a 568 goto statement, and for alternatives of a switch or case statement. 569 RTL labels generated for loops and conditionals don't go through here; 570 they are generated directly at the RTL level, by other functions below. 571 572 Note that this has nothing to do with defining label *names*. 573 Languages vary in how they do that and what that even means. */ 574 575void 576expand_label (label) 577 tree label; 578{ 579 struct label_chain *p; 580 581 do_pending_stack_adjust (); 582 emit_label (label_rtx (label)); 583 if (DECL_NAME (label)) 584 LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label)); 585 586 if (stack_block_stack != 0) 587 { 588 p = (struct label_chain *) oballoc (sizeof (struct label_chain)); 589 p->next = stack_block_stack->data.block.label_chain; 590 stack_block_stack->data.block.label_chain = p; 591 p->label = label; 592 } 593} 594 595/* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos 596 from nested functions. */ 597 598void 599declare_nonlocal_label (label) 600 tree label; 601{ 602 rtx slot = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0); 603 604 nonlocal_labels = tree_cons (NULL_TREE, label, nonlocal_labels); 605 LABEL_PRESERVE_P (label_rtx (label)) = 1; 606 if (nonlocal_goto_handler_slots == 0) 607 { 608 emit_stack_save (SAVE_NONLOCAL, 609 &nonlocal_goto_stack_level, 610 PREV_INSN (tail_recursion_reentry)); 611 } 612 nonlocal_goto_handler_slots 613 = gen_rtx_EXPR_LIST (VOIDmode, slot, nonlocal_goto_handler_slots); 614} 615 616/* Generate RTL code for a `goto' statement with target label LABEL. 617 LABEL should be a LABEL_DECL tree node that was or will later be 618 defined with `expand_label'. */ 619 620void 621expand_goto (label) 622 tree label; 623{ 624 tree context; 625 626 /* Check for a nonlocal goto to a containing function. */ 627 context = decl_function_context (label); 628 if (context != 0 && context != current_function_decl) 629 { 630 struct function *p = find_function_data (context); 631 rtx label_ref = gen_rtx_LABEL_REF (Pmode, label_rtx (label)); 632 rtx temp, handler_slot; 633 tree link; 634 635 /* Find the corresponding handler slot for this label. */ 636 handler_slot = p->nonlocal_goto_handler_slots; 637 for (link = p->nonlocal_labels; TREE_VALUE (link) != label; 638 link = TREE_CHAIN (link)) 639 handler_slot = XEXP (handler_slot, 1); 640 handler_slot = XEXP (handler_slot, 0); 641 642 p->has_nonlocal_label = 1; 643 current_function_has_nonlocal_goto = 1; 644 LABEL_REF_NONLOCAL_P (label_ref) = 1; 645 646 /* Copy the rtl for the slots so that they won't be shared in 647 case the virtual stack vars register gets instantiated differently 648 in the parent than in the child. */ 649 650#if HAVE_nonlocal_goto 651 if (HAVE_nonlocal_goto) 652 emit_insn (gen_nonlocal_goto (lookup_static_chain (label), 653 copy_rtx (handler_slot), 654 copy_rtx (p->nonlocal_goto_stack_level), 655 label_ref)); 656 else 657#endif 658 { 659 rtx addr; 660 661 /* Restore frame pointer for containing function. 662 This sets the actual hard register used for the frame pointer 663 to the location of the function's incoming static chain info. 664 The non-local goto handler will then adjust it to contain the 665 proper value and reload the argument pointer, if needed. */ 666 emit_move_insn (hard_frame_pointer_rtx, lookup_static_chain (label)); 667 668 /* We have now loaded the frame pointer hardware register with 669 the address of that corresponds to the start of the virtual 670 stack vars. So replace virtual_stack_vars_rtx in all 671 addresses we use with stack_pointer_rtx. */ 672 673 /* Get addr of containing function's current nonlocal goto handler, 674 which will do any cleanups and then jump to the label. */ 675 addr = copy_rtx (handler_slot); 676 temp = copy_to_reg (replace_rtx (addr, virtual_stack_vars_rtx, 677 hard_frame_pointer_rtx)); 678 679 /* Restore the stack pointer. Note this uses fp just restored. */ 680 addr = p->nonlocal_goto_stack_level; 681 if (addr) 682 addr = replace_rtx (copy_rtx (addr), 683 virtual_stack_vars_rtx, 684 hard_frame_pointer_rtx); 685 686 emit_stack_restore (SAVE_NONLOCAL, addr, NULL_RTX); 687 688 /* USE of hard_frame_pointer_rtx added for consistency; not clear if 689 really needed. */ 690 emit_insn (gen_rtx_USE (VOIDmode, hard_frame_pointer_rtx)); 691 emit_insn (gen_rtx_USE (VOIDmode, stack_pointer_rtx)); 692 emit_indirect_jump (temp); 693 } 694 } 695 else 696 expand_goto_internal (label, label_rtx (label), NULL_RTX); 697} 698 699/* Generate RTL code for a `goto' statement with target label BODY. 700 LABEL should be a LABEL_REF. 701 LAST_INSN, if non-0, is the rtx we should consider as the last 702 insn emitted (for the purposes of cleaning up a return). */ 703 704static void 705expand_goto_internal (body, label, last_insn) 706 tree body; 707 rtx label; 708 rtx last_insn; 709{ 710 struct nesting *block; 711 rtx stack_level = 0; 712 713 if (GET_CODE (label) != CODE_LABEL) 714 abort (); 715 716 /* If label has already been defined, we can tell now 717 whether and how we must alter the stack level. */ 718 719 if (PREV_INSN (label) != 0) 720 { 721 /* Find the innermost pending block that contains the label. 722 (Check containment by comparing insn-uids.) 723 Then restore the outermost stack level within that block, 724 and do cleanups of all blocks contained in it. */ 725 for (block = block_stack; block; block = block->next) 726 { 727 if (INSN_UID (block->data.block.first_insn) < INSN_UID (label)) 728 break; 729 if (block->data.block.stack_level != 0) 730 stack_level = block->data.block.stack_level; 731 /* Execute the cleanups for blocks we are exiting. */ 732 if (block->data.block.cleanups != 0) 733 { 734 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1); 735 do_pending_stack_adjust (); 736 } 737 } 738 739 if (stack_level) 740 { 741 /* Ensure stack adjust isn't done by emit_jump, as this 742 would clobber the stack pointer. This one should be 743 deleted as dead by flow. */ 744 clear_pending_stack_adjust (); 745 do_pending_stack_adjust (); 746 emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX); 747 } 748 749 if (body != 0 && DECL_TOO_LATE (body)) 750 error ("jump to `%s' invalidly jumps into binding contour", 751 IDENTIFIER_POINTER (DECL_NAME (body))); 752 } 753 /* Label not yet defined: may need to put this goto 754 on the fixup list. */ 755 else if (! expand_fixup (body, label, last_insn)) 756 { 757 /* No fixup needed. Record that the label is the target 758 of at least one goto that has no fixup. */ 759 if (body != 0) 760 TREE_ADDRESSABLE (body) = 1; 761 } 762 763 emit_jump (label); 764} 765 766/* Generate if necessary a fixup for a goto 767 whose target label in tree structure (if any) is TREE_LABEL 768 and whose target in rtl is RTL_LABEL. 769 770 If LAST_INSN is nonzero, we pretend that the jump appears 771 after insn LAST_INSN instead of at the current point in the insn stream. 772 773 The fixup will be used later to insert insns just before the goto. 774 Those insns will restore the stack level as appropriate for the 775 target label, and will (in the case of C++) also invoke any object 776 destructors which have to be invoked when we exit the scopes which 777 are exited by the goto. 778 779 Value is nonzero if a fixup is made. */ 780 781static int 782expand_fixup (tree_label, rtl_label, last_insn) 783 tree tree_label; 784 rtx rtl_label; 785 rtx last_insn; 786{ 787 struct nesting *block, *end_block; 788 789 /* See if we can recognize which block the label will be output in. 790 This is possible in some very common cases. 791 If we succeed, set END_BLOCK to that block. 792 Otherwise, set it to 0. */ 793 794 if (cond_stack 795 && (rtl_label == cond_stack->data.cond.endif_label 796 || rtl_label == cond_stack->data.cond.next_label)) 797 end_block = cond_stack; 798 /* If we are in a loop, recognize certain labels which 799 are likely targets. This reduces the number of fixups 800 we need to create. */ 801 else if (loop_stack 802 && (rtl_label == loop_stack->data.loop.start_label 803 || rtl_label == loop_stack->data.loop.end_label 804 || rtl_label == loop_stack->data.loop.continue_label)) 805 end_block = loop_stack; 806 else 807 end_block = 0; 808 809 /* Now set END_BLOCK to the binding level to which we will return. */ 810 811 if (end_block) 812 { 813 struct nesting *next_block = end_block->all; 814 block = block_stack; 815 816 /* First see if the END_BLOCK is inside the innermost binding level. 817 If so, then no cleanups or stack levels are relevant. */ 818 while (next_block && next_block != block) 819 next_block = next_block->all; 820 821 if (next_block) 822 return 0; 823 824 /* Otherwise, set END_BLOCK to the innermost binding level 825 which is outside the relevant control-structure nesting. */ 826 next_block = block_stack->next; 827 for (block = block_stack; block != end_block; block = block->all) 828 if (block == next_block) 829 next_block = next_block->next; 830 end_block = next_block; 831 } 832 833 /* Does any containing block have a stack level or cleanups? 834 If not, no fixup is needed, and that is the normal case 835 (the only case, for standard C). */ 836 for (block = block_stack; block != end_block; block = block->next) 837 if (block->data.block.stack_level != 0 838 || block->data.block.cleanups != 0) 839 break; 840 841 if (block != end_block) 842 { 843 /* Ok, a fixup is needed. Add a fixup to the list of such. */ 844 struct goto_fixup *fixup 845 = (struct goto_fixup *) oballoc (sizeof (struct goto_fixup)); 846 /* In case an old stack level is restored, make sure that comes 847 after any pending stack adjust. */ 848 /* ?? If the fixup isn't to come at the present position, 849 doing the stack adjust here isn't useful. Doing it with our 850 settings at that location isn't useful either. Let's hope 851 someone does it! */ 852 if (last_insn == 0) 853 do_pending_stack_adjust (); 854 fixup->target = tree_label; 855 fixup->target_rtl = rtl_label; 856 857 /* Create a BLOCK node and a corresponding matched set of 858 NOTE_INSN_BEGIN_BLOCK and NOTE_INSN_END_BLOCK notes at 859 this point. The notes will encapsulate any and all fixup 860 code which we might later insert at this point in the insn 861 stream. Also, the BLOCK node will be the parent (i.e. the 862 `SUPERBLOCK') of any other BLOCK nodes which we might create 863 later on when we are expanding the fixup code. 864 865 Note that optimization passes (including expand_end_loop) 866 might move the *_BLOCK notes away, so we use a NOTE_INSN_DELETED 867 as a placeholder. */ 868 869 { 870 register rtx original_before_jump 871 = last_insn ? last_insn : get_last_insn (); 872 rtx start; 873 874 start_sequence (); 875 pushlevel (0); 876 start = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG); 877 fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_DELETED); 878 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END); 879 fixup->context = poplevel (1, 0, 0); /* Create the BLOCK node now! */ 880 end_sequence (); 881 emit_insns_after (start, original_before_jump); 882 } 883 884 fixup->block_start_count = block_start_count; 885 fixup->stack_level = 0; 886 fixup->cleanup_list_list 887 = ((block->data.block.outer_cleanups 888 || block->data.block.cleanups) 889 ? tree_cons (NULL_TREE, block->data.block.cleanups, 890 block->data.block.outer_cleanups) 891 : 0); 892 fixup->next = goto_fixup_chain; 893 goto_fixup_chain = fixup; 894 } 895 896 return block != 0; 897} 898 899 900 901/* Expand any needed fixups in the outputmost binding level of the 902 function. FIRST_INSN is the first insn in the function. */ 903 904void 905expand_fixups (first_insn) 906 rtx first_insn; 907{ 908 fixup_gotos (NULL_PTR, NULL_RTX, NULL_TREE, first_insn, 0); 909} 910 911/* When exiting a binding contour, process all pending gotos requiring fixups. 912 THISBLOCK is the structure that describes the block being exited. 913 STACK_LEVEL is the rtx for the stack level to restore exiting this contour. 914 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour. 915 FIRST_INSN is the insn that began this contour. 916 917 Gotos that jump out of this contour must restore the 918 stack level and do the cleanups before actually jumping. 919 920 DONT_JUMP_IN nonzero means report error there is a jump into this 921 contour from before the beginning of the contour. 922 This is also done if STACK_LEVEL is nonzero. */ 923 924static void 925fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in) 926 struct nesting *thisblock; 927 rtx stack_level; 928 tree cleanup_list; 929 rtx first_insn; 930 int dont_jump_in; 931{ 932 register struct goto_fixup *f, *prev; 933 934 /* F is the fixup we are considering; PREV is the previous one. */ 935 /* We run this loop in two passes so that cleanups of exited blocks 936 are run first, and blocks that are exited are marked so 937 afterwards. */ 938 939 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next) 940 { 941 /* Test for a fixup that is inactive because it is already handled. */ 942 if (f->before_jump == 0) 943 { 944 /* Delete inactive fixup from the chain, if that is easy to do. */ 945 if (prev != 0) 946 prev->next = f->next; 947 } 948 /* Has this fixup's target label been defined? 949 If so, we can finalize it. */ 950 else if (PREV_INSN (f->target_rtl) != 0) 951 { 952 register rtx cleanup_insns; 953 954 /* Get the first non-label after the label 955 this goto jumps to. If that's before this scope begins, 956 we don't have a jump into the scope. */ 957 rtx after_label = f->target_rtl; 958 while (after_label != 0 && GET_CODE (after_label) == CODE_LABEL) 959 after_label = NEXT_INSN (after_label); 960 961 /* If this fixup jumped into this contour from before the beginning 962 of this contour, report an error. */ 963 /* ??? Bug: this does not detect jumping in through intermediate 964 blocks that have stack levels or cleanups. 965 It detects only a problem with the innermost block 966 around the label. */ 967 if (f->target != 0 968 && (dont_jump_in || stack_level || cleanup_list) 969 /* If AFTER_LABEL is 0, it means the jump goes to the end 970 of the rtl, which means it jumps into this scope. */ 971 && (after_label == 0 972 || INSN_UID (first_insn) < INSN_UID (after_label)) 973 && INSN_UID (first_insn) > INSN_UID (f->before_jump) 974 && ! DECL_ERROR_ISSUED (f->target)) 975 { 976 error_with_decl (f->target, 977 "label `%s' used before containing binding contour"); 978 /* Prevent multiple errors for one label. */ 979 DECL_ERROR_ISSUED (f->target) = 1; 980 } 981 982 /* We will expand the cleanups into a sequence of their own and 983 then later on we will attach this new sequence to the insn 984 stream just ahead of the actual jump insn. */ 985 986 start_sequence (); 987 988 /* Temporarily restore the lexical context where we will 989 logically be inserting the fixup code. We do this for the 990 sake of getting the debugging information right. */ 991 992 pushlevel (0); 993 set_block (f->context); 994 995 /* Expand the cleanups for blocks this jump exits. */ 996 if (f->cleanup_list_list) 997 { 998 tree lists; 999 for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists)) 1000 /* Marked elements correspond to blocks that have been closed. 1001 Do their cleanups. */ 1002 if (TREE_ADDRESSABLE (lists) 1003 && TREE_VALUE (lists) != 0) 1004 { 1005 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1); 1006 /* Pop any pushes done in the cleanups, 1007 in case function is about to return. */ 1008 do_pending_stack_adjust (); 1009 } 1010 } 1011 1012 /* Restore stack level for the biggest contour that this 1013 jump jumps out of. */ 1014 if (f->stack_level) 1015 emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump); 1016 1017 /* Finish up the sequence containing the insns which implement the 1018 necessary cleanups, and then attach that whole sequence to the 1019 insn stream just ahead of the actual jump insn. Attaching it 1020 at that point insures that any cleanups which are in fact 1021 implicit C++ object destructions (which must be executed upon 1022 leaving the block) appear (to the debugger) to be taking place 1023 in an area of the generated code where the object(s) being 1024 destructed are still "in scope". */ 1025 1026 cleanup_insns = get_insns (); 1027 poplevel (1, 0, 0); 1028 1029 end_sequence (); 1030 emit_insns_after (cleanup_insns, f->before_jump); 1031 1032 1033 f->before_jump = 0; 1034 } 1035 } 1036 1037 /* For any still-undefined labels, do the cleanups for this block now. 1038 We must do this now since items in the cleanup list may go out 1039 of scope when the block ends. */ 1040 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next) 1041 if (f->before_jump != 0 1042 && PREV_INSN (f->target_rtl) == 0 1043 /* Label has still not appeared. If we are exiting a block with 1044 a stack level to restore, that started before the fixup, 1045 mark this stack level as needing restoration 1046 when the fixup is later finalized. */ 1047 && thisblock != 0 1048 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it 1049 means the label is undefined. That's erroneous, but possible. */ 1050 && (thisblock->data.block.block_start_count 1051 <= f->block_start_count)) 1052 { 1053 tree lists = f->cleanup_list_list; 1054 rtx cleanup_insns; 1055 1056 for (; lists; lists = TREE_CHAIN (lists)) 1057 /* If the following elt. corresponds to our containing block 1058 then the elt. must be for this block. */ 1059 if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups) 1060 { 1061 start_sequence (); 1062 pushlevel (0); 1063 set_block (f->context); 1064 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1); 1065 do_pending_stack_adjust (); 1066 cleanup_insns = get_insns (); 1067 poplevel (1, 0, 0); 1068 end_sequence (); 1069 if (cleanup_insns != 0) 1070 f->before_jump 1071 = emit_insns_after (cleanup_insns, f->before_jump); 1072 1073 f->cleanup_list_list = TREE_CHAIN (lists); 1074 } 1075 1076 if (stack_level) 1077 f->stack_level = stack_level; 1078 } 1079} 1080 1081/* Return the number of times character C occurs in string S. */ 1082static int 1083n_occurrences (c, s) 1084 int c; 1085 const char *s; 1086{ 1087 int n = 0; 1088 while (*s) 1089 n += (*s++ == c); 1090 return n; 1091} 1092 1093/* Generate RTL for an asm statement (explicit assembler code). 1094 BODY is a STRING_CST node containing the assembler code text, 1095 or an ADDR_EXPR containing a STRING_CST. */ 1096 1097void 1098expand_asm (body) 1099 tree body; 1100{ 1101 if (current_function_check_memory_usage) 1102 { 1103 error ("`asm' cannot be used with `-fcheck-memory-usage'"); 1104 return; 1105 } 1106 1107 if (TREE_CODE (body) == ADDR_EXPR) 1108 body = TREE_OPERAND (body, 0); 1109 1110 emit_insn (gen_rtx_ASM_INPUT (VOIDmode, 1111 TREE_STRING_POINTER (body))); 1112 last_expr_type = 0; 1113} 1114 1115/* Generate RTL for an asm statement with arguments. 1116 STRING is the instruction template. 1117 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs. 1118 Each output or input has an expression in the TREE_VALUE and 1119 a constraint-string in the TREE_PURPOSE. 1120 CLOBBERS is a list of STRING_CST nodes each naming a hard register 1121 that is clobbered by this insn. 1122 1123 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly. 1124 Some elements of OUTPUTS may be replaced with trees representing temporary 1125 values. The caller should copy those temporary values to the originally 1126 specified lvalues. 1127 1128 VOL nonzero means the insn is volatile; don't optimize it. */ 1129 1130void 1131expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line) 1132 tree string, outputs, inputs, clobbers; 1133 int vol; 1134 char *filename; 1135 int line; 1136{ 1137 rtvec argvec, constraints; 1138 rtx body; 1139 int ninputs = list_length (inputs); 1140 int noutputs = list_length (outputs); 1141 int ninout = 0; 1142 int nclobbers; 1143 tree tail; 1144 register int i; 1145 /* Vector of RTX's of evaluated output operands. */ 1146 rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx)); 1147 int *inout_opnum = (int *) alloca (noutputs * sizeof (int)); 1148 rtx *real_output_rtx = (rtx *) alloca (noutputs * sizeof (rtx)); 1149 enum machine_mode *inout_mode 1150 = (enum machine_mode *) alloca (noutputs * sizeof (enum machine_mode)); 1151 /* The insn we have emitted. */ 1152 rtx insn; 1153 1154 /* An ASM with no outputs needs to be treated as volatile, for now. */ 1155 if (noutputs == 0) 1156 vol = 1; 1157 1158 if (current_function_check_memory_usage) 1159 { 1160 error ("`asm' cannot be used with `-fcheck-memory-usage'"); 1161 return; 1162 } 1163 1164 /* Count the number of meaningful clobbered registers, ignoring what 1165 we would ignore later. */ 1166 nclobbers = 0; 1167 for (tail = clobbers; tail; tail = TREE_CHAIN (tail)) 1168 { 1169 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail)); 1170 i = decode_reg_name (regname); 1171 if (i >= 0 || i == -4) 1172 ++nclobbers; 1173 else if (i == -2) 1174 error ("unknown register name `%s' in `asm'", regname); 1175 } 1176 1177 last_expr_type = 0; 1178 1179 /* Check that the number of alternatives is constant across all 1180 operands. */ 1181 if (outputs || inputs) 1182 { 1183 tree tmp = TREE_PURPOSE (outputs ? outputs : inputs); 1184 int nalternatives = n_occurrences (',', TREE_STRING_POINTER (tmp)); 1185 tree next = inputs; 1186 1187 if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES) 1188 { 1189 error ("too many alternatives in `asm'"); 1190 return; 1191 } 1192 1193 tmp = outputs; 1194 while (tmp) 1195 { 1196 char *constraint = TREE_STRING_POINTER (TREE_PURPOSE (tmp)); 1197 if (n_occurrences (',', constraint) != nalternatives) 1198 { 1199 error ("operand constraints for `asm' differ in number of alternatives"); 1200 return; 1201 } 1202 if (TREE_CHAIN (tmp)) 1203 tmp = TREE_CHAIN (tmp); 1204 else 1205 tmp = next, next = 0; 1206 } 1207 } 1208 1209 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++) 1210 { 1211 tree val = TREE_VALUE (tail); 1212 tree type = TREE_TYPE (val); 1213 char *constraint; 1214 char *p; 1215 int c_len; 1216 int j; 1217 int is_inout = 0; 1218 int allows_reg = 0; 1219 int allows_mem = 0; 1220 1221 /* If there's an erroneous arg, emit no insn. */ 1222 if (TREE_TYPE (val) == error_mark_node) 1223 return; 1224 1225 /* Make sure constraint has `=' and does not have `+'. Also, see 1226 if it allows any register. Be liberal on the latter test, since 1227 the worst that happens if we get it wrong is we issue an error 1228 message. */ 1229 1230 c_len = TREE_STRING_LENGTH (TREE_PURPOSE (tail)) - 1; 1231 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail)); 1232 1233 /* Allow the `=' or `+' to not be at the beginning of the string, 1234 since it wasn't explicitly documented that way, and there is a 1235 large body of code that puts it last. Swap the character to 1236 the front, so as not to uglify any place else. */ 1237 switch (c_len) 1238 { 1239 default: 1240 if ((p = strchr (constraint, '=')) != NULL) 1241 break; 1242 if ((p = strchr (constraint, '+')) != NULL) 1243 break; 1244 case 0: 1245 error ("output operand constraint lacks `='"); 1246 return; 1247 } 1248 1249 if (p != constraint) 1250 { 1251 j = *p; 1252 bcopy (constraint, constraint+1, p-constraint); 1253 *constraint = j; 1254 1255 warning ("output constraint `%c' for operand %d is not at the beginning", j, i); 1256 } 1257 1258 is_inout = constraint[0] == '+'; 1259 /* Replace '+' with '='. */ 1260 constraint[0] = '='; 1261 /* Make sure we can specify the matching operand. */ 1262 if (is_inout && i > 9) 1263 { 1264 error ("output operand constraint %d contains `+'", i); 1265 return; 1266 } 1267 1268 for (j = 1; j < c_len; j++) 1269 switch (constraint[j]) 1270 { 1271 case '+': 1272 case '=': 1273 error ("operand constraint contains '+' or '=' at illegal position."); 1274 return; 1275 1276 case '%': 1277 if (i + 1 == ninputs + noutputs) 1278 { 1279 error ("`%%' constraint used with last operand"); 1280 return; 1281 } 1282 break; 1283 1284 case '?': case '!': case '*': case '&': 1285 case 'E': case 'F': case 'G': case 'H': 1286 case 's': case 'i': case 'n': 1287 case 'I': case 'J': case 'K': case 'L': case 'M': 1288 case 'N': case 'O': case 'P': case ',': 1289#ifdef EXTRA_CONSTRAINT 1290 case 'Q': case 'R': case 'S': case 'T': case 'U': 1291#endif 1292 break; 1293 1294 case '0': case '1': case '2': case '3': case '4': 1295 case '5': case '6': case '7': case '8': case '9': 1296 error ("matching constraint not valid in output operand"); 1297 break; 1298 1299 case 'V': case 'm': case 'o': 1300 allows_mem = 1; 1301 break; 1302 1303 case '<': case '>': 1304 /* ??? Before flow, auto inc/dec insns are not supposed to exist, 1305 excepting those that expand_call created. So match memory 1306 and hope. */ 1307 allows_mem = 1; 1308 break; 1309 1310 case 'g': case 'X': 1311 allows_reg = 1; 1312 allows_mem = 1; 1313 break; 1314 1315 case 'p': case 'r': 1316 default: 1317 allows_reg = 1; 1318 break; 1319 } 1320 1321 /* If an output operand is not a decl or indirect ref and our constraint 1322 allows a register, make a temporary to act as an intermediate. 1323 Make the asm insn write into that, then our caller will copy it to 1324 the real output operand. Likewise for promoted variables. */ 1325 1326 real_output_rtx[i] = NULL_RTX; 1327 if ((TREE_CODE (val) == INDIRECT_REF 1328 && allows_mem) 1329 || (TREE_CODE_CLASS (TREE_CODE (val)) == 'd' 1330 && (allows_mem || GET_CODE (DECL_RTL (val)) == REG) 1331 && ! (GET_CODE (DECL_RTL (val)) == REG 1332 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type))) 1333 || ! allows_reg 1334 || is_inout) 1335 { 1336 if (! allows_reg) 1337 mark_addressable (TREE_VALUE (tail)); 1338 1339 output_rtx[i] 1340 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 1341 EXPAND_MEMORY_USE_WO); 1342 1343 if (! allows_reg && GET_CODE (output_rtx[i]) != MEM) 1344 error ("output number %d not directly addressable", i); 1345 if (! allows_mem && GET_CODE (output_rtx[i]) == MEM) 1346 { 1347 real_output_rtx[i] = protect_from_queue (output_rtx[i], 1); 1348 output_rtx[i] = gen_reg_rtx (GET_MODE (output_rtx[i])); 1349 if (is_inout) 1350 emit_move_insn (output_rtx[i], real_output_rtx[i]); 1351 } 1352 } 1353 else 1354 { 1355 output_rtx[i] = assign_temp (type, 0, 0, 1); 1356 TREE_VALUE (tail) = make_tree (type, output_rtx[i]); 1357 } 1358 1359 if (is_inout) 1360 { 1361 inout_mode[ninout] = TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))); 1362 inout_opnum[ninout++] = i; 1363 } 1364 } 1365 1366 ninputs += ninout; 1367 if (ninputs + noutputs > MAX_RECOG_OPERANDS) 1368 { 1369 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS); 1370 return; 1371 } 1372 1373 /* Make vectors for the expression-rtx and constraint strings. */ 1374 1375 argvec = rtvec_alloc (ninputs); 1376 constraints = rtvec_alloc (ninputs); 1377 1378 body = gen_rtx_ASM_OPERANDS (VOIDmode, 1379 TREE_STRING_POINTER (string), "", 0, argvec, 1380 constraints, filename, line); 1381 1382 MEM_VOLATILE_P (body) = vol; 1383 1384 /* Eval the inputs and put them into ARGVEC. 1385 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */ 1386 1387 i = 0; 1388 for (tail = inputs; tail; tail = TREE_CHAIN (tail)) 1389 { 1390 int j; 1391 int allows_reg = 0, allows_mem = 0; 1392 char *constraint, *orig_constraint; 1393 int c_len; 1394 rtx op; 1395 1396 /* If there's an erroneous arg, emit no insn, 1397 because the ASM_INPUT would get VOIDmode 1398 and that could cause a crash in reload. */ 1399 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node) 1400 return; 1401 1402 /* ??? Can this happen, and does the error message make any sense? */ 1403 if (TREE_PURPOSE (tail) == NULL_TREE) 1404 { 1405 error ("hard register `%s' listed as input operand to `asm'", 1406 TREE_STRING_POINTER (TREE_VALUE (tail)) ); 1407 return; 1408 } 1409 1410 c_len = TREE_STRING_LENGTH (TREE_PURPOSE (tail)) - 1; 1411 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail)); 1412 orig_constraint = constraint; 1413 1414 /* Make sure constraint has neither `=', `+', nor '&'. */ 1415 1416 for (j = 0; j < c_len; j++) 1417 switch (constraint[j]) 1418 { 1419 case '+': case '=': case '&': 1420 if (constraint == orig_constraint) 1421 { 1422 error ("input operand constraint contains `%c'", constraint[j]); 1423 return; 1424 } 1425 break; 1426 1427 case '%': 1428 if (constraint == orig_constraint 1429 && i + 1 == ninputs - ninout) 1430 { 1431 error ("`%%' constraint used with last operand"); 1432 return; 1433 } 1434 break; 1435 1436 case 'V': case 'm': case 'o': 1437 allows_mem = 1; 1438 break; 1439 1440 case '<': case '>': 1441 case '?': case '!': case '*': 1442 case 'E': case 'F': case 'G': case 'H': case 'X': 1443 case 's': case 'i': case 'n': 1444 case 'I': case 'J': case 'K': case 'L': case 'M': 1445 case 'N': case 'O': case 'P': case ',': 1446#ifdef EXTRA_CONSTRAINT 1447 case 'Q': case 'R': case 'S': case 'T': case 'U': 1448#endif 1449 break; 1450 1451 /* Whether or not a numeric constraint allows a register is 1452 decided by the matching constraint, and so there is no need 1453 to do anything special with them. We must handle them in 1454 the default case, so that we don't unnecessarily force 1455 operands to memory. */ 1456 case '0': case '1': case '2': case '3': case '4': 1457 case '5': case '6': case '7': case '8': case '9': 1458 if (constraint[j] >= '0' + noutputs) 1459 { 1460 error 1461 ("matching constraint references invalid operand number"); 1462 return; 1463 } 1464 1465 /* Try and find the real constraint for this dup. */ 1466 if ((j == 0 && c_len == 1) 1467 || (j == 1 && c_len == 2 && constraint[0] == '%')) 1468 { 1469 tree o = outputs; 1470 for (j = constraint[j] - '0'; j > 0; --j) 1471 o = TREE_CHAIN (o); 1472 1473 c_len = TREE_STRING_LENGTH (TREE_PURPOSE (o)) - 1; 1474 constraint = TREE_STRING_POINTER (TREE_PURPOSE (o)); 1475 j = 0; 1476 break; 1477 } 1478 1479 /* ... fall through ... */ 1480 1481 case 'p': case 'r': 1482 default: 1483 allows_reg = 1; 1484 break; 1485 1486 case 'g': 1487 allows_reg = 1; 1488 allows_mem = 1; 1489 break; 1490 } 1491 1492 if (! allows_reg && allows_mem) 1493 mark_addressable (TREE_VALUE (tail)); 1494 1495 op = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0); 1496 1497 if (asm_operand_ok (op, constraint) <= 0) 1498 { 1499 if (allows_reg) 1500 op = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))), op); 1501 else if (!allows_mem) 1502 warning ("asm operand %d probably doesn't match constraints", i); 1503 else if (CONSTANT_P (op)) 1504 op = force_const_mem (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))), 1505 op); 1506 else if (GET_CODE (op) == REG 1507 || GET_CODE (op) == SUBREG 1508 || GET_CODE (op) == CONCAT) 1509 { 1510 tree type = TREE_TYPE (TREE_VALUE (tail)); 1511 rtx memloc = assign_temp (type, 1, 1, 1); 1512 1513 emit_move_insn (memloc, op); 1514 op = memloc; 1515 } 1516 else if (GET_CODE (op) == MEM && MEM_VOLATILE_P (op)) 1517 /* We won't recognize volatile memory as available a 1518 memory_operand at this point. Ignore it. */ 1519 ; 1520 else if (queued_subexp_p (op)) 1521 ; 1522 else 1523 /* ??? Leave this only until we have experience with what 1524 happens in combine and elsewhere when constraints are 1525 not satisfied. */ 1526 warning ("asm operand %d probably doesn't match constraints", i); 1527 } 1528 XVECEXP (body, 3, i) = op; 1529 1530 XVECEXP (body, 4, i) /* constraints */ 1531 = gen_rtx_ASM_INPUT (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))), 1532 orig_constraint); 1533 i++; 1534 } 1535 1536 /* Protect all the operands from the queue, 1537 now that they have all been evaluated. */ 1538 1539 for (i = 0; i < ninputs - ninout; i++) 1540 XVECEXP (body, 3, i) = protect_from_queue (XVECEXP (body, 3, i), 0); 1541 1542 for (i = 0; i < noutputs; i++) 1543 output_rtx[i] = protect_from_queue (output_rtx[i], 1); 1544 1545 /* For in-out operands, copy output rtx to input rtx. */ 1546 for (i = 0; i < ninout; i++) 1547 { 1548 static char match[9+1][2] 1549 = {"0", "1", "2", "3", "4", "5", "6", "7", "8", "9"}; 1550 int j = inout_opnum[i]; 1551 1552 XVECEXP (body, 3, ninputs - ninout + i) /* argvec */ 1553 = output_rtx[j]; 1554 XVECEXP (body, 4, ninputs - ninout + i) /* constraints */ 1555 = gen_rtx_ASM_INPUT (inout_mode[j], match[j]); 1556 } 1557 1558 /* Now, for each output, construct an rtx 1559 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT 1560 ARGVEC CONSTRAINTS)) 1561 If there is more than one, put them inside a PARALLEL. */ 1562 1563 if (noutputs == 1 && nclobbers == 0) 1564 { 1565 XSTR (body, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs)); 1566 insn = emit_insn (gen_rtx_SET (VOIDmode, output_rtx[0], body)); 1567 } 1568 else if (noutputs == 0 && nclobbers == 0) 1569 { 1570 /* No output operands: put in a raw ASM_OPERANDS rtx. */ 1571 insn = emit_insn (body); 1572 } 1573 else 1574 { 1575 rtx obody = body; 1576 int num = noutputs; 1577 if (num == 0) num = 1; 1578 body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers)); 1579 1580 /* For each output operand, store a SET. */ 1581 1582 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++) 1583 { 1584 XVECEXP (body, 0, i) 1585 = gen_rtx_SET (VOIDmode, 1586 output_rtx[i], 1587 gen_rtx_ASM_OPERANDS (VOIDmode, 1588 TREE_STRING_POINTER (string), 1589 TREE_STRING_POINTER (TREE_PURPOSE (tail)), 1590 i, argvec, constraints, 1591 filename, line)); 1592 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol; 1593 } 1594 1595 /* If there are no outputs (but there are some clobbers) 1596 store the bare ASM_OPERANDS into the PARALLEL. */ 1597 1598 if (i == 0) 1599 XVECEXP (body, 0, i++) = obody; 1600 1601 /* Store (clobber REG) for each clobbered register specified. */ 1602 1603 for (tail = clobbers; tail; tail = TREE_CHAIN (tail)) 1604 { 1605 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail)); 1606 int j = decode_reg_name (regname); 1607 1608 if (j < 0) 1609 { 1610 if (j == -3) /* `cc', which is not a register */ 1611 continue; 1612 1613 if (j == -4) /* `memory', don't cache memory across asm */ 1614 { 1615 XVECEXP (body, 0, i++) 1616 = gen_rtx_CLOBBER (VOIDmode, 1617 gen_rtx_MEM (BLKmode, 1618 gen_rtx_SCRATCH (VOIDmode))); 1619 continue; 1620 } 1621 1622 /* Ignore unknown register, error already signaled. */ 1623 continue; 1624 } 1625 1626 /* Use QImode since that's guaranteed to clobber just one reg. */ 1627 XVECEXP (body, 0, i++) 1628 = gen_rtx_CLOBBER (VOIDmode, gen_rtx_REG (QImode, j)); 1629 } 1630 1631 insn = emit_insn (body); 1632 } 1633 1634 /* For any outputs that needed reloading into registers, spill them 1635 back to where they belong. */ 1636 for (i = 0; i < noutputs; ++i) 1637 if (real_output_rtx[i]) 1638 emit_move_insn (real_output_rtx[i], output_rtx[i]); 1639 1640 free_temp_slots (); 1641} 1642 1643/* Generate RTL to evaluate the expression EXP 1644 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */ 1645 1646void 1647expand_expr_stmt (exp) 1648 tree exp; 1649{ 1650 /* If -W, warn about statements with no side effects, 1651 except for an explicit cast to void (e.g. for assert()), and 1652 except inside a ({...}) where they may be useful. */ 1653 if (expr_stmts_for_value == 0 && exp != error_mark_node) 1654 { 1655 if (! TREE_SIDE_EFFECTS (exp) && (extra_warnings || warn_unused) 1656 && !(TREE_CODE (exp) == CONVERT_EXPR 1657 && TREE_TYPE (exp) == void_type_node)) 1658 warning_with_file_and_line (emit_filename, emit_lineno, 1659 "statement with no effect"); 1660 else if (warn_unused) 1661 warn_if_unused_value (exp); 1662 } 1663 1664 /* If EXP is of function type and we are expanding statements for 1665 value, convert it to pointer-to-function. */ 1666 if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE) 1667 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp); 1668 1669 last_expr_type = TREE_TYPE (exp); 1670 last_expr_value = expand_expr (exp, 1671 (expr_stmts_for_value 1672 ? NULL_RTX : const0_rtx), 1673 VOIDmode, 0); 1674 1675 /* If all we do is reference a volatile value in memory, 1676 copy it to a register to be sure it is actually touched. */ 1677 if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM 1678 && TREE_THIS_VOLATILE (exp)) 1679 { 1680 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode) 1681 ; 1682 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode) 1683 copy_to_reg (last_expr_value); 1684 else 1685 { 1686 rtx lab = gen_label_rtx (); 1687 1688 /* Compare the value with itself to reference it. */ 1689 emit_cmp_and_jump_insns (last_expr_value, last_expr_value, EQ, 1690 expand_expr (TYPE_SIZE (last_expr_type), 1691 NULL_RTX, VOIDmode, 0), 1692 BLKmode, 0, 1693 TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT, 1694 lab); 1695 emit_label (lab); 1696 } 1697 } 1698 1699 /* If this expression is part of a ({...}) and is in memory, we may have 1700 to preserve temporaries. */ 1701 preserve_temp_slots (last_expr_value); 1702 1703 /* Free any temporaries used to evaluate this expression. Any temporary 1704 used as a result of this expression will already have been preserved 1705 above. */ 1706 free_temp_slots (); 1707 1708 emit_queue (); 1709} 1710 1711/* Warn if EXP contains any computations whose results are not used. 1712 Return 1 if a warning is printed; 0 otherwise. */ 1713 1714int 1715warn_if_unused_value (exp) 1716 tree exp; 1717{ 1718 if (TREE_USED (exp)) 1719 return 0; 1720 1721 switch (TREE_CODE (exp)) 1722 { 1723 case PREINCREMENT_EXPR: 1724 case POSTINCREMENT_EXPR: 1725 case PREDECREMENT_EXPR: 1726 case POSTDECREMENT_EXPR: 1727 case MODIFY_EXPR: 1728 case INIT_EXPR: 1729 case TARGET_EXPR: 1730 case CALL_EXPR: 1731 case METHOD_CALL_EXPR: 1732 case RTL_EXPR: 1733 case TRY_CATCH_EXPR: 1734 case WITH_CLEANUP_EXPR: 1735 case EXIT_EXPR: 1736 /* We don't warn about COND_EXPR because it may be a useful 1737 construct if either arm contains a side effect. */ 1738 case COND_EXPR: 1739 return 0; 1740 1741 case BIND_EXPR: 1742 /* For a binding, warn if no side effect within it. */ 1743 return warn_if_unused_value (TREE_OPERAND (exp, 1)); 1744 1745 case SAVE_EXPR: 1746 return warn_if_unused_value (TREE_OPERAND (exp, 1)); 1747 1748 case TRUTH_ORIF_EXPR: 1749 case TRUTH_ANDIF_EXPR: 1750 /* In && or ||, warn if 2nd operand has no side effect. */ 1751 return warn_if_unused_value (TREE_OPERAND (exp, 1)); 1752 1753 case COMPOUND_EXPR: 1754 if (TREE_NO_UNUSED_WARNING (exp)) 1755 return 0; 1756 if (warn_if_unused_value (TREE_OPERAND (exp, 0))) 1757 return 1; 1758 /* Let people do `(foo (), 0)' without a warning. */ 1759 if (TREE_CONSTANT (TREE_OPERAND (exp, 1))) 1760 return 0; 1761 return warn_if_unused_value (TREE_OPERAND (exp, 1)); 1762 1763 case NOP_EXPR: 1764 case CONVERT_EXPR: 1765 case NON_LVALUE_EXPR: 1766 /* Don't warn about values cast to void. */ 1767 if (TREE_TYPE (exp) == void_type_node) 1768 return 0; 1769 /* Don't warn about conversions not explicit in the user's program. */ 1770 if (TREE_NO_UNUSED_WARNING (exp)) 1771 return 0; 1772 /* Assignment to a cast usually results in a cast of a modify. 1773 Don't complain about that. There can be an arbitrary number of 1774 casts before the modify, so we must loop until we find the first 1775 non-cast expression and then test to see if that is a modify. */ 1776 { 1777 tree tem = TREE_OPERAND (exp, 0); 1778 1779 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR) 1780 tem = TREE_OPERAND (tem, 0); 1781 1782 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR 1783 || TREE_CODE (tem) == CALL_EXPR) 1784 return 0; 1785 } 1786 goto warn; 1787 1788 case INDIRECT_REF: 1789 /* Don't warn about automatic dereferencing of references, since 1790 the user cannot control it. */ 1791 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE) 1792 return warn_if_unused_value (TREE_OPERAND (exp, 0)); 1793 /* ... fall through ... */ 1794 1795 default: 1796 /* Referencing a volatile value is a side effect, so don't warn. */ 1797 if ((TREE_CODE_CLASS (TREE_CODE (exp)) == 'd' 1798 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r') 1799 && TREE_THIS_VOLATILE (exp)) 1800 return 0; 1801 warn: 1802 warning_with_file_and_line (emit_filename, emit_lineno, 1803 "value computed is not used"); 1804 return 1; 1805 } 1806} 1807 1808/* Clear out the memory of the last expression evaluated. */ 1809 1810void 1811clear_last_expr () 1812{ 1813 last_expr_type = 0; 1814} 1815 1816/* Begin a statement which will return a value. 1817 Return the RTL_EXPR for this statement expr. 1818 The caller must save that value and pass it to expand_end_stmt_expr. */ 1819 1820tree 1821expand_start_stmt_expr () 1822{ 1823 int momentary; 1824 tree t; 1825 1826 /* Make the RTL_EXPR node temporary, not momentary, 1827 so that rtl_expr_chain doesn't become garbage. */ 1828 momentary = suspend_momentary (); 1829 t = make_node (RTL_EXPR); 1830 resume_momentary (momentary); 1831 do_pending_stack_adjust (); 1832 start_sequence_for_rtl_expr (t); 1833 NO_DEFER_POP; 1834 expr_stmts_for_value++; 1835 return t; 1836} 1837 1838/* Restore the previous state at the end of a statement that returns a value. 1839 Returns a tree node representing the statement's value and the 1840 insns to compute the value. 1841 1842 The nodes of that expression have been freed by now, so we cannot use them. 1843 But we don't want to do that anyway; the expression has already been 1844 evaluated and now we just want to use the value. So generate a RTL_EXPR 1845 with the proper type and RTL value. 1846 1847 If the last substatement was not an expression, 1848 return something with type `void'. */ 1849 1850tree 1851expand_end_stmt_expr (t) 1852 tree t; 1853{ 1854 OK_DEFER_POP; 1855 1856 if (last_expr_type == 0) 1857 { 1858 last_expr_type = void_type_node; 1859 last_expr_value = const0_rtx; 1860 } 1861 else if (last_expr_value == 0) 1862 /* There are some cases where this can happen, such as when the 1863 statement is void type. */ 1864 last_expr_value = const0_rtx; 1865 else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value)) 1866 /* Remove any possible QUEUED. */ 1867 last_expr_value = protect_from_queue (last_expr_value, 0); 1868 1869 emit_queue (); 1870 1871 TREE_TYPE (t) = last_expr_type; 1872 RTL_EXPR_RTL (t) = last_expr_value; 1873 RTL_EXPR_SEQUENCE (t) = get_insns (); 1874 1875 rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain); 1876 1877 end_sequence (); 1878 1879 /* Don't consider deleting this expr or containing exprs at tree level. */ 1880 TREE_SIDE_EFFECTS (t) = 1; 1881 /* Propagate volatility of the actual RTL expr. */ 1882 TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value); 1883 1884 last_expr_type = 0; 1885 expr_stmts_for_value--; 1886 1887 return t; 1888} 1889 1890/* Generate RTL for the start of an if-then. COND is the expression 1891 whose truth should be tested. 1892 1893 If EXITFLAG is nonzero, this conditional is visible to 1894 `exit_something'. */ 1895 1896void 1897expand_start_cond (cond, exitflag) 1898 tree cond; 1899 int exitflag; 1900{ 1901 struct nesting *thiscond = ALLOC_NESTING (); 1902 1903 /* Make an entry on cond_stack for the cond we are entering. */ 1904 1905 thiscond->next = cond_stack; 1906 thiscond->all = nesting_stack; 1907 thiscond->depth = ++nesting_depth; 1908 thiscond->data.cond.next_label = gen_label_rtx (); 1909 /* Before we encounter an `else', we don't need a separate exit label 1910 unless there are supposed to be exit statements 1911 to exit this conditional. */ 1912 thiscond->exit_label = exitflag ? gen_label_rtx () : 0; 1913 thiscond->data.cond.endif_label = thiscond->exit_label; 1914 cond_stack = thiscond; 1915 nesting_stack = thiscond; 1916 1917 do_jump (cond, thiscond->data.cond.next_label, NULL_RTX); 1918} 1919 1920/* Generate RTL between then-clause and the elseif-clause 1921 of an if-then-elseif-.... */ 1922 1923void 1924expand_start_elseif (cond) 1925 tree cond; 1926{ 1927 if (cond_stack->data.cond.endif_label == 0) 1928 cond_stack->data.cond.endif_label = gen_label_rtx (); 1929 emit_jump (cond_stack->data.cond.endif_label); 1930 emit_label (cond_stack->data.cond.next_label); 1931 cond_stack->data.cond.next_label = gen_label_rtx (); 1932 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX); 1933} 1934 1935/* Generate RTL between the then-clause and the else-clause 1936 of an if-then-else. */ 1937 1938void 1939expand_start_else () 1940{ 1941 if (cond_stack->data.cond.endif_label == 0) 1942 cond_stack->data.cond.endif_label = gen_label_rtx (); 1943 1944 emit_jump (cond_stack->data.cond.endif_label); 1945 emit_label (cond_stack->data.cond.next_label); 1946 cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */ 1947} 1948 1949/* After calling expand_start_else, turn this "else" into an "else if" 1950 by providing another condition. */ 1951 1952void 1953expand_elseif (cond) 1954 tree cond; 1955{ 1956 cond_stack->data.cond.next_label = gen_label_rtx (); 1957 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX); 1958} 1959 1960/* Generate RTL for the end of an if-then. 1961 Pop the record for it off of cond_stack. */ 1962 1963void 1964expand_end_cond () 1965{ 1966 struct nesting *thiscond = cond_stack; 1967 1968 do_pending_stack_adjust (); 1969 if (thiscond->data.cond.next_label) 1970 emit_label (thiscond->data.cond.next_label); 1971 if (thiscond->data.cond.endif_label) 1972 emit_label (thiscond->data.cond.endif_label); 1973 1974 POPSTACK (cond_stack); 1975 last_expr_type = 0; 1976} 1977 1978 1979 1980/* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this 1981 loop should be exited by `exit_something'. This is a loop for which 1982 `expand_continue' will jump to the top of the loop. 1983 1984 Make an entry on loop_stack to record the labels associated with 1985 this loop. */ 1986 1987struct nesting * 1988expand_start_loop (exit_flag) 1989 int exit_flag; 1990{ 1991 register struct nesting *thisloop = ALLOC_NESTING (); 1992 1993 /* Make an entry on loop_stack for the loop we are entering. */ 1994 1995 thisloop->next = loop_stack; 1996 thisloop->all = nesting_stack; 1997 thisloop->depth = ++nesting_depth; 1998 thisloop->data.loop.start_label = gen_label_rtx (); 1999 thisloop->data.loop.end_label = gen_label_rtx (); 2000 thisloop->data.loop.alt_end_label = 0; 2001 thisloop->data.loop.continue_label = thisloop->data.loop.start_label; 2002 thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0; 2003 loop_stack = thisloop; 2004 nesting_stack = thisloop; 2005 2006 do_pending_stack_adjust (); 2007 emit_queue (); 2008 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG); 2009 emit_label (thisloop->data.loop.start_label); 2010 2011 return thisloop; 2012} 2013 2014/* Like expand_start_loop but for a loop where the continuation point 2015 (for expand_continue_loop) will be specified explicitly. */ 2016 2017struct nesting * 2018expand_start_loop_continue_elsewhere (exit_flag) 2019 int exit_flag; 2020{ 2021 struct nesting *thisloop = expand_start_loop (exit_flag); 2022 loop_stack->data.loop.continue_label = gen_label_rtx (); 2023 return thisloop; 2024} 2025 2026/* Specify the continuation point for a loop started with 2027 expand_start_loop_continue_elsewhere. 2028 Use this at the point in the code to which a continue statement 2029 should jump. */ 2030 2031void 2032expand_loop_continue_here () 2033{ 2034 do_pending_stack_adjust (); 2035 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT); 2036 emit_label (loop_stack->data.loop.continue_label); 2037} 2038 2039/* Finish a loop. Generate a jump back to the top and the loop-exit label. 2040 Pop the block off of loop_stack. */ 2041 2042void 2043expand_end_loop () 2044{ 2045 rtx start_label = loop_stack->data.loop.start_label; 2046 rtx insn = get_last_insn (); 2047 int needs_end_jump = 1; 2048 2049 /* Mark the continue-point at the top of the loop if none elsewhere. */ 2050 if (start_label == loop_stack->data.loop.continue_label) 2051 emit_note_before (NOTE_INSN_LOOP_CONT, start_label); 2052 2053 do_pending_stack_adjust (); 2054 2055 /* If optimizing, perhaps reorder the loop. 2056 First, try to use a condjump near the end. 2057 expand_exit_loop_if_false ends loops with unconditional jumps, 2058 like this: 2059 2060 if (test) goto label; 2061 optional: cleanup 2062 goto loop_stack->data.loop.end_label 2063 barrier 2064 label: 2065 2066 If we find such a pattern, we can end the loop earlier. */ 2067 2068 if (optimize 2069 && GET_CODE (insn) == CODE_LABEL 2070 && LABEL_NAME (insn) == NULL 2071 && GET_CODE (PREV_INSN (insn)) == BARRIER) 2072 { 2073 rtx label = insn; 2074 rtx jump = PREV_INSN (PREV_INSN (label)); 2075 2076 if (GET_CODE (jump) == JUMP_INSN 2077 && GET_CODE (PATTERN (jump)) == SET 2078 && SET_DEST (PATTERN (jump)) == pc_rtx 2079 && GET_CODE (SET_SRC (PATTERN (jump))) == LABEL_REF 2080 && (XEXP (SET_SRC (PATTERN (jump)), 0) 2081 == loop_stack->data.loop.end_label)) 2082 { 2083 rtx prev; 2084 2085 /* The test might be complex and reference LABEL multiple times, 2086 like the loop in loop_iterations to set vtop. To handle this, 2087 we move LABEL. */ 2088 insn = PREV_INSN (label); 2089 reorder_insns (label, label, start_label); 2090 2091 for (prev = PREV_INSN (jump); ; prev = PREV_INSN (prev)) 2092 { 2093 /* We ignore line number notes, but if we see any other note, 2094 in particular NOTE_INSN_BLOCK_*, NOTE_INSN_EH_REGION_*, 2095 NOTE_INSN_LOOP_*, we disable this optimization. */ 2096 if (GET_CODE (prev) == NOTE) 2097 { 2098 if (NOTE_LINE_NUMBER (prev) < 0) 2099 break; 2100 continue; 2101 } 2102 if (GET_CODE (prev) == CODE_LABEL) 2103 break; 2104 if (GET_CODE (prev) == JUMP_INSN) 2105 { 2106 if (GET_CODE (PATTERN (prev)) == SET 2107 && SET_DEST (PATTERN (prev)) == pc_rtx 2108 && GET_CODE (SET_SRC (PATTERN (prev))) == IF_THEN_ELSE 2109 && (GET_CODE (XEXP (SET_SRC (PATTERN (prev)), 1)) 2110 == LABEL_REF) 2111 && XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0) == label) 2112 { 2113 XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0) 2114 = start_label; 2115 emit_note_after (NOTE_INSN_LOOP_END, prev); 2116 needs_end_jump = 0; 2117 } 2118 break; 2119 } 2120 } 2121 } 2122 } 2123 2124 /* If the loop starts with a loop exit, roll that to the end where 2125 it will optimize together with the jump back. 2126 2127 We look for the conditional branch to the exit, except that once 2128 we find such a branch, we don't look past 30 instructions. 2129 2130 In more detail, if the loop presently looks like this (in pseudo-C): 2131 2132 start_label: 2133 if (test) goto end_label; 2134 body; 2135 goto start_label; 2136 end_label: 2137 2138 transform it to look like: 2139 2140 goto start_label; 2141 newstart_label: 2142 body; 2143 start_label: 2144 if (test) goto end_label; 2145 goto newstart_label; 2146 end_label: 2147 2148 Here, the `test' may actually consist of some reasonably complex 2149 code, terminating in a test. */ 2150 2151 if (optimize 2152 && needs_end_jump 2153 && 2154 ! (GET_CODE (insn) == JUMP_INSN 2155 && GET_CODE (PATTERN (insn)) == SET 2156 && SET_DEST (PATTERN (insn)) == pc_rtx 2157 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE)) 2158 { 2159 int eh_regions = 0; 2160 int num_insns = 0; 2161 rtx last_test_insn = NULL_RTX; 2162 2163 /* Scan insns from the top of the loop looking for a qualified 2164 conditional exit. */ 2165 for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn; 2166 insn = NEXT_INSN (insn)) 2167 { 2168 if (GET_CODE (insn) == NOTE) 2169 { 2170 if (optimize < 2 2171 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG 2172 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)) 2173 /* The code that actually moves the exit test will 2174 carefully leave BLOCK notes in their original 2175 location. That means, however, that we can't debug 2176 the exit test itself. So, we refuse to move code 2177 containing BLOCK notes at low optimization levels. */ 2178 break; 2179 2180 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG) 2181 ++eh_regions; 2182 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END) 2183 { 2184 --eh_regions; 2185 if (eh_regions < 0) 2186 /* We've come to the end of an EH region, but 2187 never saw the beginning of that region. That 2188 means that an EH region begins before the top 2189 of the loop, and ends in the middle of it. The 2190 existence of such a situation violates a basic 2191 assumption in this code, since that would imply 2192 that even when EH_REGIONS is zero, we might 2193 move code out of an exception region. */ 2194 abort (); 2195 } 2196 2197 /* We must not walk into a nested loop. */ 2198 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG) 2199 break; 2200 2201 /* We already know this INSN is a NOTE, so there's no 2202 point in looking at it to see if it's a JUMP. */ 2203 continue; 2204 } 2205 2206 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN) 2207 num_insns++; 2208 2209 if (last_test_insn && num_insns > 30) 2210 break; 2211 2212 if (eh_regions > 0) 2213 /* We don't want to move a partial EH region. Consider: 2214 2215 while ( ( { try { 2216 if (cond ()) 0; 2217 else { 2218 bar(); 2219 1; 2220 } 2221 } catch (...) { 2222 1; 2223 } )) { 2224 body; 2225 } 2226 2227 This isn't legal C++, but here's what it's supposed to 2228 mean: if cond() is true, stop looping. Otherwise, 2229 call bar, and keep looping. In addition, if cond 2230 throws an exception, catch it and keep looping. Such 2231 constructs are certainy legal in LISP. 2232 2233 We should not move the `if (cond()) 0' test since then 2234 the EH-region for the try-block would be broken up. 2235 (In this case we would the EH_BEG note for the `try' 2236 and `if cond()' but not the call to bar() or the 2237 EH_END note.) 2238 2239 So we don't look for tests within an EH region. */ 2240 continue; 2241 2242 if (GET_CODE (insn) == JUMP_INSN 2243 && GET_CODE (PATTERN (insn)) == SET 2244 && SET_DEST (PATTERN (insn)) == pc_rtx) 2245 { 2246 /* This is indeed a jump. */ 2247 rtx dest1 = NULL_RTX; 2248 rtx dest2 = NULL_RTX; 2249 rtx potential_last_test; 2250 if (GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE) 2251 { 2252 /* A conditional jump. */ 2253 dest1 = XEXP (SET_SRC (PATTERN (insn)), 1); 2254 dest2 = XEXP (SET_SRC (PATTERN (insn)), 2); 2255 potential_last_test = insn; 2256 } 2257 else 2258 { 2259 /* An unconditional jump. */ 2260 dest1 = SET_SRC (PATTERN (insn)); 2261 /* Include the BARRIER after the JUMP. */ 2262 potential_last_test = NEXT_INSN (insn); 2263 } 2264 2265 do { 2266 if (dest1 && GET_CODE (dest1) == LABEL_REF 2267 && ((XEXP (dest1, 0) 2268 == loop_stack->data.loop.alt_end_label) 2269 || (XEXP (dest1, 0) 2270 == loop_stack->data.loop.end_label))) 2271 { 2272 last_test_insn = potential_last_test; 2273 break; 2274 } 2275 2276 /* If this was a conditional jump, there may be 2277 another label at which we should look. */ 2278 dest1 = dest2; 2279 dest2 = NULL_RTX; 2280 } while (dest1); 2281 } 2282 } 2283 2284 if (last_test_insn != 0 && last_test_insn != get_last_insn ()) 2285 { 2286 /* We found one. Move everything from there up 2287 to the end of the loop, and add a jump into the loop 2288 to jump to there. */ 2289 register rtx newstart_label = gen_label_rtx (); 2290 register rtx start_move = start_label; 2291 rtx next_insn; 2292 2293 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note, 2294 then we want to move this note also. */ 2295 if (GET_CODE (PREV_INSN (start_move)) == NOTE 2296 && (NOTE_LINE_NUMBER (PREV_INSN (start_move)) 2297 == NOTE_INSN_LOOP_CONT)) 2298 start_move = PREV_INSN (start_move); 2299 2300 emit_label_after (newstart_label, PREV_INSN (start_move)); 2301 2302 /* Actually move the insns. Start at the beginning, and 2303 keep copying insns until we've copied the 2304 last_test_insn. */ 2305 for (insn = start_move; insn; insn = next_insn) 2306 { 2307 /* Figure out which insn comes after this one. We have 2308 to do this before we move INSN. */ 2309 if (insn == last_test_insn) 2310 /* We've moved all the insns. */ 2311 next_insn = NULL_RTX; 2312 else 2313 next_insn = NEXT_INSN (insn); 2314 2315 if (GET_CODE (insn) == NOTE 2316 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG 2317 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)) 2318 /* We don't want to move NOTE_INSN_BLOCK_BEGs or 2319 NOTE_INSN_BLOCK_ENDs because the correct generation 2320 of debugging information depends on these appearing 2321 in the same order in the RTL and in the tree 2322 structure, where they are represented as BLOCKs. 2323 So, we don't move block notes. Of course, moving 2324 the code inside the block is likely to make it 2325 impossible to debug the instructions in the exit 2326 test, but such is the price of optimization. */ 2327 continue; 2328 2329 /* Move the INSN. */ 2330 reorder_insns (insn, insn, get_last_insn ()); 2331 } 2332 2333 emit_jump_insn_after (gen_jump (start_label), 2334 PREV_INSN (newstart_label)); 2335 emit_barrier_after (PREV_INSN (newstart_label)); 2336 start_label = newstart_label; 2337 } 2338 } 2339 2340 if (needs_end_jump) 2341 { 2342 emit_jump (start_label); 2343 emit_note (NULL_PTR, NOTE_INSN_LOOP_END); 2344 } 2345 emit_label (loop_stack->data.loop.end_label); 2346 2347 POPSTACK (loop_stack); 2348 2349 last_expr_type = 0; 2350} 2351 2352/* Generate a jump to the current loop's continue-point. 2353 This is usually the top of the loop, but may be specified 2354 explicitly elsewhere. If not currently inside a loop, 2355 return 0 and do nothing; caller will print an error message. */ 2356 2357int 2358expand_continue_loop (whichloop) 2359 struct nesting *whichloop; 2360{ 2361 last_expr_type = 0; 2362 if (whichloop == 0) 2363 whichloop = loop_stack; 2364 if (whichloop == 0) 2365 return 0; 2366 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label, 2367 NULL_RTX); 2368 return 1; 2369} 2370 2371/* Generate a jump to exit the current loop. If not currently inside a loop, 2372 return 0 and do nothing; caller will print an error message. */ 2373 2374int 2375expand_exit_loop (whichloop) 2376 struct nesting *whichloop; 2377{ 2378 last_expr_type = 0; 2379 if (whichloop == 0) 2380 whichloop = loop_stack; 2381 if (whichloop == 0) 2382 return 0; 2383 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX); 2384 return 1; 2385} 2386 2387/* Generate a conditional jump to exit the current loop if COND 2388 evaluates to zero. If not currently inside a loop, 2389 return 0 and do nothing; caller will print an error message. */ 2390 2391int 2392expand_exit_loop_if_false (whichloop, cond) 2393 struct nesting *whichloop; 2394 tree cond; 2395{ 2396 rtx label = gen_label_rtx (); 2397 rtx last_insn; 2398 last_expr_type = 0; 2399 2400 if (whichloop == 0) 2401 whichloop = loop_stack; 2402 if (whichloop == 0) 2403 return 0; 2404 /* In order to handle fixups, we actually create a conditional jump 2405 around a unconditional branch to exit the loop. If fixups are 2406 necessary, they go before the unconditional branch. */ 2407 2408 2409 do_jump (cond, NULL_RTX, label); 2410 last_insn = get_last_insn (); 2411 if (GET_CODE (last_insn) == CODE_LABEL) 2412 whichloop->data.loop.alt_end_label = last_insn; 2413 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, 2414 NULL_RTX); 2415 emit_label (label); 2416 2417 return 1; 2418} 2419 2420/* Return nonzero if the loop nest is empty. Else return zero. */ 2421 2422int 2423stmt_loop_nest_empty () 2424{ 2425 return (loop_stack == NULL); 2426} 2427 2428/* Return non-zero if we should preserve sub-expressions as separate 2429 pseudos. We never do so if we aren't optimizing. We always do so 2430 if -fexpensive-optimizations. 2431 2432 Otherwise, we only do so if we are in the "early" part of a loop. I.e., 2433 the loop may still be a small one. */ 2434 2435int 2436preserve_subexpressions_p () 2437{ 2438 rtx insn; 2439 2440 if (flag_expensive_optimizations) 2441 return 1; 2442 2443 if (optimize == 0 || loop_stack == 0) 2444 return 0; 2445 2446 insn = get_last_insn_anywhere (); 2447 2448 return (insn 2449 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label) 2450 < n_non_fixed_regs * 3)); 2451 2452} 2453 2454/* Generate a jump to exit the current loop, conditional, binding contour 2455 or case statement. Not all such constructs are visible to this function, 2456 only those started with EXIT_FLAG nonzero. Individual languages use 2457 the EXIT_FLAG parameter to control which kinds of constructs you can 2458 exit this way. 2459 2460 If not currently inside anything that can be exited, 2461 return 0 and do nothing; caller will print an error message. */ 2462 2463int 2464expand_exit_something () 2465{ 2466 struct nesting *n; 2467 last_expr_type = 0; 2468 for (n = nesting_stack; n; n = n->all) 2469 if (n->exit_label != 0) 2470 { 2471 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX); 2472 return 1; 2473 } 2474 2475 return 0; 2476} 2477 2478/* Generate RTL to return from the current function, with no value. 2479 (That is, we do not do anything about returning any value.) */ 2480 2481void 2482expand_null_return () 2483{ 2484 struct nesting *block = block_stack; 2485 rtx last_insn = 0; 2486 2487 /* Does any pending block have cleanups? */ 2488 2489 while (block && block->data.block.cleanups == 0) 2490 block = block->next; 2491 2492 /* If yes, use a goto to return, since that runs cleanups. */ 2493 2494 expand_null_return_1 (last_insn, block != 0); 2495} 2496 2497/* Generate RTL to return from the current function, with value VAL. */ 2498 2499static void 2500expand_value_return (val) 2501 rtx val; 2502{ 2503 struct nesting *block = block_stack; 2504 rtx last_insn = get_last_insn (); 2505 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl)); 2506 2507 /* Copy the value to the return location 2508 unless it's already there. */ 2509 2510 if (return_reg != val) 2511 { 2512#ifdef PROMOTE_FUNCTION_RETURN 2513 tree type = TREE_TYPE (DECL_RESULT (current_function_decl)); 2514 int unsignedp = TREE_UNSIGNED (type); 2515 enum machine_mode old_mode 2516 = DECL_MODE (DECL_RESULT (current_function_decl)); 2517 enum machine_mode mode 2518 = promote_mode (type, old_mode, &unsignedp, 1); 2519 2520 if (mode != old_mode) 2521 val = convert_modes (mode, old_mode, val, unsignedp); 2522#endif 2523 emit_move_insn (return_reg, val); 2524 } 2525 if (GET_CODE (return_reg) == REG 2526 && REGNO (return_reg) < FIRST_PSEUDO_REGISTER) 2527 emit_insn (gen_rtx_USE (VOIDmode, return_reg)); 2528 /* Handle calls that return values in multiple non-contiguous locations. 2529 The Irix 6 ABI has examples of this. */ 2530 else if (GET_CODE (return_reg) == PARALLEL) 2531 { 2532 int i; 2533 2534 for (i = 0; i < XVECLEN (return_reg, 0); i++) 2535 { 2536 rtx x = XEXP (XVECEXP (return_reg, 0, i), 0); 2537 2538 if (GET_CODE (x) == REG 2539 && REGNO (x) < FIRST_PSEUDO_REGISTER) 2540 emit_insn (gen_rtx_USE (VOIDmode, x)); 2541 } 2542 } 2543 2544 /* Does any pending block have cleanups? */ 2545 2546 while (block && block->data.block.cleanups == 0) 2547 block = block->next; 2548 2549 /* If yes, use a goto to return, since that runs cleanups. 2550 Use LAST_INSN to put cleanups *before* the move insn emitted above. */ 2551 2552 expand_null_return_1 (last_insn, block != 0); 2553} 2554 2555/* Output a return with no value. If LAST_INSN is nonzero, 2556 pretend that the return takes place after LAST_INSN. 2557 If USE_GOTO is nonzero then don't use a return instruction; 2558 go to the return label instead. This causes any cleanups 2559 of pending blocks to be executed normally. */ 2560 2561static void 2562expand_null_return_1 (last_insn, use_goto) 2563 rtx last_insn; 2564 int use_goto; 2565{ 2566 rtx end_label = cleanup_label ? cleanup_label : return_label; 2567 2568 clear_pending_stack_adjust (); 2569 do_pending_stack_adjust (); 2570 last_expr_type = 0; 2571 2572 /* PCC-struct return always uses an epilogue. */ 2573 if (current_function_returns_pcc_struct || use_goto) 2574 { 2575 if (end_label == 0) 2576 end_label = return_label = gen_label_rtx (); 2577 expand_goto_internal (NULL_TREE, end_label, last_insn); 2578 return; 2579 } 2580 2581 /* Otherwise output a simple return-insn if one is available, 2582 unless it won't do the job. */ 2583#ifdef HAVE_return 2584 if (HAVE_return && use_goto == 0 && cleanup_label == 0) 2585 { 2586 emit_jump_insn (gen_return ()); 2587 emit_barrier (); 2588 return; 2589 } 2590#endif 2591 2592 /* Otherwise jump to the epilogue. */ 2593 expand_goto_internal (NULL_TREE, end_label, last_insn); 2594} 2595 2596/* Generate RTL to evaluate the expression RETVAL and return it 2597 from the current function. */ 2598 2599void 2600expand_return (retval) 2601 tree retval; 2602{ 2603 /* If there are any cleanups to be performed, then they will 2604 be inserted following LAST_INSN. It is desirable 2605 that the last_insn, for such purposes, should be the 2606 last insn before computing the return value. Otherwise, cleanups 2607 which call functions can clobber the return value. */ 2608 /* ??? rms: I think that is erroneous, because in C++ it would 2609 run destructors on variables that might be used in the subsequent 2610 computation of the return value. */ 2611 rtx last_insn = 0; 2612 register rtx val = 0; 2613 register rtx op0; 2614 tree retval_rhs; 2615 int cleanups; 2616 2617 /* If function wants no value, give it none. */ 2618 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE) 2619 { 2620 expand_expr (retval, NULL_RTX, VOIDmode, 0); 2621 emit_queue (); 2622 expand_null_return (); 2623 return; 2624 } 2625 2626 /* Are any cleanups needed? E.g. C++ destructors to be run? */ 2627 /* This is not sufficient. We also need to watch for cleanups of the 2628 expression we are about to expand. Unfortunately, we cannot know 2629 if it has cleanups until we expand it, and we want to change how we 2630 expand it depending upon if we need cleanups. We can't win. */ 2631#if 0 2632 cleanups = any_pending_cleanups (1); 2633#else 2634 cleanups = 1; 2635#endif 2636 2637 if (TREE_CODE (retval) == RESULT_DECL) 2638 retval_rhs = retval; 2639 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR) 2640 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL) 2641 retval_rhs = TREE_OPERAND (retval, 1); 2642 else if (TREE_TYPE (retval) == void_type_node) 2643 /* Recognize tail-recursive call to void function. */ 2644 retval_rhs = retval; 2645 else 2646 retval_rhs = NULL_TREE; 2647 2648 /* Only use `last_insn' if there are cleanups which must be run. */ 2649 if (cleanups || cleanup_label != 0) 2650 last_insn = get_last_insn (); 2651 2652 /* Distribute return down conditional expr if either of the sides 2653 may involve tail recursion (see test below). This enhances the number 2654 of tail recursions we see. Don't do this always since it can produce 2655 sub-optimal code in some cases and we distribute assignments into 2656 conditional expressions when it would help. */ 2657 2658 if (optimize && retval_rhs != 0 2659 && frame_offset == 0 2660 && TREE_CODE (retval_rhs) == COND_EXPR 2661 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR 2662 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR)) 2663 { 2664 rtx label = gen_label_rtx (); 2665 tree expr; 2666 2667 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX); 2668 start_cleanup_deferral (); 2669 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)), 2670 DECL_RESULT (current_function_decl), 2671 TREE_OPERAND (retval_rhs, 1)); 2672 TREE_SIDE_EFFECTS (expr) = 1; 2673 expand_return (expr); 2674 emit_label (label); 2675 2676 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)), 2677 DECL_RESULT (current_function_decl), 2678 TREE_OPERAND (retval_rhs, 2)); 2679 TREE_SIDE_EFFECTS (expr) = 1; 2680 expand_return (expr); 2681 end_cleanup_deferral (); 2682 return; 2683 } 2684 2685 /* Attempt to optimize the call if it is tail recursive. */ 2686 if (optimize_tail_recursion (retval_rhs, last_insn)) 2687 return; 2688 2689#ifdef HAVE_return 2690 /* This optimization is safe if there are local cleanups 2691 because expand_null_return takes care of them. 2692 ??? I think it should also be safe when there is a cleanup label, 2693 because expand_null_return takes care of them, too. 2694 Any reason why not? */ 2695 if (HAVE_return && cleanup_label == 0 2696 && ! current_function_returns_pcc_struct 2697 && BRANCH_COST <= 1) 2698 { 2699 /* If this is return x == y; then generate 2700 if (x == y) return 1; else return 0; 2701 if we can do it with explicit return insns and branches are cheap, 2702 but not if we have the corresponding scc insn. */ 2703 int has_scc = 0; 2704 if (retval_rhs) 2705 switch (TREE_CODE (retval_rhs)) 2706 { 2707 case EQ_EXPR: 2708#ifdef HAVE_seq 2709 has_scc = HAVE_seq; 2710#endif 2711 case NE_EXPR: 2712#ifdef HAVE_sne 2713 has_scc = HAVE_sne; 2714#endif 2715 case GT_EXPR: 2716#ifdef HAVE_sgt 2717 has_scc = HAVE_sgt; 2718#endif 2719 case GE_EXPR: 2720#ifdef HAVE_sge 2721 has_scc = HAVE_sge; 2722#endif 2723 case LT_EXPR: 2724#ifdef HAVE_slt 2725 has_scc = HAVE_slt; 2726#endif 2727 case LE_EXPR: 2728#ifdef HAVE_sle 2729 has_scc = HAVE_sle; 2730#endif 2731 case TRUTH_ANDIF_EXPR: 2732 case TRUTH_ORIF_EXPR: 2733 case TRUTH_AND_EXPR: 2734 case TRUTH_OR_EXPR: 2735 case TRUTH_NOT_EXPR: 2736 case TRUTH_XOR_EXPR: 2737 if (! has_scc) 2738 { 2739 op0 = gen_label_rtx (); 2740 jumpifnot (retval_rhs, op0); 2741 expand_value_return (const1_rtx); 2742 emit_label (op0); 2743 expand_value_return (const0_rtx); 2744 return; 2745 } 2746 break; 2747 2748 default: 2749 break; 2750 } 2751 } 2752#endif /* HAVE_return */ 2753 2754 /* If the result is an aggregate that is being returned in one (or more) 2755 registers, load the registers here. The compiler currently can't handle 2756 copying a BLKmode value into registers. We could put this code in a 2757 more general area (for use by everyone instead of just function 2758 call/return), but until this feature is generally usable it is kept here 2759 (and in expand_call). The value must go into a pseudo in case there 2760 are cleanups that will clobber the real return register. */ 2761 2762 if (retval_rhs != 0 2763 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode 2764 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG) 2765 { 2766 int i, bitpos, xbitpos; 2767 int big_endian_correction = 0; 2768 int bytes = int_size_in_bytes (TREE_TYPE (retval_rhs)); 2769 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD; 2770 int bitsize = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)), 2771 (unsigned int)BITS_PER_WORD); 2772 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs); 2773 rtx result_reg, src = NULL_RTX, dst = NULL_RTX; 2774 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0); 2775 enum machine_mode tmpmode, result_reg_mode; 2776 2777 /* Structures whose size is not a multiple of a word are aligned 2778 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN 2779 machine, this means we must skip the empty high order bytes when 2780 calculating the bit offset. */ 2781 if (BYTES_BIG_ENDIAN && bytes % UNITS_PER_WORD) 2782 big_endian_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD) 2783 * BITS_PER_UNIT)); 2784 2785 /* Copy the structure BITSIZE bits at a time. */ 2786 for (bitpos = 0, xbitpos = big_endian_correction; 2787 bitpos < bytes * BITS_PER_UNIT; 2788 bitpos += bitsize, xbitpos += bitsize) 2789 { 2790 /* We need a new destination pseudo each time xbitpos is 2791 on a word boundary and when xbitpos == big_endian_correction 2792 (the first time through). */ 2793 if (xbitpos % BITS_PER_WORD == 0 2794 || xbitpos == big_endian_correction) 2795 { 2796 /* Generate an appropriate register. */ 2797 dst = gen_reg_rtx (word_mode); 2798 result_pseudos[xbitpos / BITS_PER_WORD] = dst; 2799 2800 /* Clobber the destination before we move anything into it. */ 2801 emit_insn (gen_rtx_CLOBBER (VOIDmode, dst)); 2802 } 2803 2804 /* We need a new source operand each time bitpos is on a word 2805 boundary. */ 2806 if (bitpos % BITS_PER_WORD == 0) 2807 src = operand_subword_force (result_val, 2808 bitpos / BITS_PER_WORD, 2809 BLKmode); 2810 2811 /* Use bitpos for the source extraction (left justified) and 2812 xbitpos for the destination store (right justified). */ 2813 store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode, 2814 extract_bit_field (src, bitsize, 2815 bitpos % BITS_PER_WORD, 1, 2816 NULL_RTX, word_mode, 2817 word_mode, 2818 bitsize / BITS_PER_UNIT, 2819 BITS_PER_WORD), 2820 bitsize / BITS_PER_UNIT, BITS_PER_WORD); 2821 } 2822 2823 /* Find the smallest integer mode large enough to hold the 2824 entire structure and use that mode instead of BLKmode 2825 on the USE insn for the return register. */ 2826 bytes = int_size_in_bytes (TREE_TYPE (retval_rhs)); 2827 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT); 2828 tmpmode != MAX_MACHINE_MODE; 2829 tmpmode = GET_MODE_WIDER_MODE (tmpmode)) 2830 { 2831 /* Have we found a large enough mode? */ 2832 if (GET_MODE_SIZE (tmpmode) >= bytes) 2833 break; 2834 } 2835 2836 /* No suitable mode found. */ 2837 if (tmpmode == MAX_MACHINE_MODE) 2838 abort (); 2839 2840 PUT_MODE (DECL_RTL (DECL_RESULT (current_function_decl)), tmpmode); 2841 2842 if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode)) 2843 result_reg_mode = word_mode; 2844 else 2845 result_reg_mode = tmpmode; 2846 result_reg = gen_reg_rtx (result_reg_mode); 2847 2848 emit_queue (); 2849 for (i = 0; i < n_regs; i++) 2850 emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode), 2851 result_pseudos[i]); 2852 2853 if (tmpmode != result_reg_mode) 2854 result_reg = gen_lowpart (tmpmode, result_reg); 2855 2856 expand_value_return (result_reg); 2857 } 2858 else if (cleanups 2859 && retval_rhs != 0 2860 && TREE_TYPE (retval_rhs) != void_type_node 2861 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG) 2862 { 2863 /* Calculate the return value into a pseudo reg. */ 2864 val = gen_reg_rtx (DECL_MODE (DECL_RESULT (current_function_decl))); 2865 val = expand_expr (retval_rhs, val, GET_MODE (val), 0); 2866 val = force_not_mem (val); 2867 emit_queue (); 2868 /* Return the calculated value, doing cleanups first. */ 2869 expand_value_return (val); 2870 } 2871 else 2872 { 2873 /* No cleanups or no hard reg used; 2874 calculate value into hard return reg. */ 2875 expand_expr (retval, const0_rtx, VOIDmode, 0); 2876 emit_queue (); 2877 expand_value_return (DECL_RTL (DECL_RESULT (current_function_decl))); 2878 } 2879} 2880 2881/* Return 1 if the end of the generated RTX is not a barrier. 2882 This means code already compiled can drop through. */ 2883 2884int 2885drop_through_at_end_p () 2886{ 2887 rtx insn = get_last_insn (); 2888 while (insn && GET_CODE (insn) == NOTE) 2889 insn = PREV_INSN (insn); 2890 return insn && GET_CODE (insn) != BARRIER; 2891} 2892 2893/* Test CALL_EXPR to determine if it is a potential tail recursion call 2894 and emit code to optimize the tail recursion. LAST_INSN indicates where 2895 to place the jump to the tail recursion label. Return TRUE if the 2896 call was optimized into a goto. 2897 2898 This is only used by expand_return, but expand_call is expected to 2899 use it soon. */ 2900 2901int 2902optimize_tail_recursion (call_expr, last_insn) 2903 tree call_expr; 2904 rtx last_insn; 2905{ 2906 /* For tail-recursive call to current function, 2907 just jump back to the beginning. 2908 It's unsafe if any auto variable in this function 2909 has its address taken; for simplicity, 2910 require stack frame to be empty. */ 2911 if (optimize && call_expr != 0 2912 && frame_offset == 0 2913 && TREE_CODE (call_expr) == CALL_EXPR 2914 && TREE_CODE (TREE_OPERAND (call_expr, 0)) == ADDR_EXPR 2915 && TREE_OPERAND (TREE_OPERAND (call_expr, 0), 0) == current_function_decl 2916 /* Finish checking validity, and if valid emit code 2917 to set the argument variables for the new call. */ 2918 && tail_recursion_args (TREE_OPERAND (call_expr, 1), 2919 DECL_ARGUMENTS (current_function_decl))) 2920 { 2921 if (tail_recursion_label == 0) 2922 { 2923 tail_recursion_label = gen_label_rtx (); 2924 emit_label_after (tail_recursion_label, 2925 tail_recursion_reentry); 2926 } 2927 emit_queue (); 2928 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn); 2929 emit_barrier (); 2930 return 1; 2931 } 2932 2933 return 0; 2934} 2935 2936/* Emit code to alter this function's formal parms for a tail-recursive call. 2937 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs). 2938 FORMALS is the chain of decls of formals. 2939 Return 1 if this can be done; 2940 otherwise return 0 and do not emit any code. */ 2941 2942static int 2943tail_recursion_args (actuals, formals) 2944 tree actuals, formals; 2945{ 2946 register tree a = actuals, f = formals; 2947 register int i; 2948 register rtx *argvec; 2949 2950 /* Check that number and types of actuals are compatible 2951 with the formals. This is not always true in valid C code. 2952 Also check that no formal needs to be addressable 2953 and that all formals are scalars. */ 2954 2955 /* Also count the args. */ 2956 2957 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++) 2958 { 2959 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a))) 2960 != TYPE_MAIN_VARIANT (TREE_TYPE (f))) 2961 return 0; 2962 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode) 2963 return 0; 2964 } 2965 if (a != 0 || f != 0) 2966 return 0; 2967 2968 /* Compute all the actuals. */ 2969 2970 argvec = (rtx *) alloca (i * sizeof (rtx)); 2971 2972 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++) 2973 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0); 2974 2975 /* Find which actual values refer to current values of previous formals. 2976 Copy each of them now, before any formal is changed. */ 2977 2978 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++) 2979 { 2980 int copy = 0; 2981 register int j; 2982 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++) 2983 if (reg_mentioned_p (DECL_RTL (f), argvec[i])) 2984 { copy = 1; break; } 2985 if (copy) 2986 argvec[i] = copy_to_reg (argvec[i]); 2987 } 2988 2989 /* Store the values of the actuals into the formals. */ 2990 2991 for (f = formals, a = actuals, i = 0; f; 2992 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++) 2993 { 2994 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i])) 2995 emit_move_insn (DECL_RTL (f), argvec[i]); 2996 else 2997 convert_move (DECL_RTL (f), argvec[i], 2998 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a)))); 2999 } 3000 3001 free_temp_slots (); 3002 return 1; 3003} 3004 3005/* Generate the RTL code for entering a binding contour. 3006 The variables are declared one by one, by calls to `expand_decl'. 3007 3008 EXIT_FLAG is nonzero if this construct should be visible to 3009 `exit_something'. */ 3010 3011void 3012expand_start_bindings (exit_flag) 3013 int exit_flag; 3014{ 3015 struct nesting *thisblock = ALLOC_NESTING (); 3016 rtx note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG); 3017 3018 /* Make an entry on block_stack for the block we are entering. */ 3019 3020 thisblock->next = block_stack; 3021 thisblock->all = nesting_stack; 3022 thisblock->depth = ++nesting_depth; 3023 thisblock->data.block.stack_level = 0; 3024 thisblock->data.block.cleanups = 0; 3025 thisblock->data.block.function_call_count = 0; 3026 thisblock->data.block.exception_region = 0; 3027 thisblock->data.block.target_temp_slot_level = target_temp_slot_level; 3028 3029 thisblock->data.block.conditional_code = 0; 3030 thisblock->data.block.last_unconditional_cleanup = note; 3031 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups; 3032 3033 if (block_stack 3034 && !(block_stack->data.block.cleanups == NULL_TREE 3035 && block_stack->data.block.outer_cleanups == NULL_TREE)) 3036 thisblock->data.block.outer_cleanups 3037 = tree_cons (NULL_TREE, block_stack->data.block.cleanups, 3038 block_stack->data.block.outer_cleanups); 3039 else 3040 thisblock->data.block.outer_cleanups = 0; 3041 thisblock->data.block.label_chain = 0; 3042 thisblock->data.block.innermost_stack_block = stack_block_stack; 3043 thisblock->data.block.first_insn = note; 3044 thisblock->data.block.block_start_count = ++block_start_count; 3045 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0; 3046 block_stack = thisblock; 3047 nesting_stack = thisblock; 3048 3049 /* Make a new level for allocating stack slots. */ 3050 push_temp_slots (); 3051} 3052 3053/* Specify the scope of temporaries created by TARGET_EXPRs. Similar 3054 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to 3055 expand_expr are made. After we end the region, we know that all 3056 space for all temporaries that were created by TARGET_EXPRs will be 3057 destroyed and their space freed for reuse. */ 3058 3059void 3060expand_start_target_temps () 3061{ 3062 /* This is so that even if the result is preserved, the space 3063 allocated will be freed, as we know that it is no longer in use. */ 3064 push_temp_slots (); 3065 3066 /* Start a new binding layer that will keep track of all cleanup 3067 actions to be performed. */ 3068 expand_start_bindings (0); 3069 3070 target_temp_slot_level = temp_slot_level; 3071} 3072 3073void 3074expand_end_target_temps () 3075{ 3076 expand_end_bindings (NULL_TREE, 0, 0); 3077 3078 /* This is so that even if the result is preserved, the space 3079 allocated will be freed, as we know that it is no longer in use. */ 3080 pop_temp_slots (); 3081} 3082 3083/* Mark top block of block_stack as an implicit binding for an 3084 exception region. This is used to prevent infinite recursion when 3085 ending a binding with expand_end_bindings. It is only ever called 3086 by expand_eh_region_start, as that it the only way to create a 3087 block stack for a exception region. */ 3088 3089void 3090mark_block_as_eh_region () 3091{ 3092 block_stack->data.block.exception_region = 1; 3093 if (block_stack->next 3094 && block_stack->next->data.block.conditional_code) 3095 { 3096 block_stack->data.block.conditional_code 3097 = block_stack->next->data.block.conditional_code; 3098 block_stack->data.block.last_unconditional_cleanup 3099 = block_stack->next->data.block.last_unconditional_cleanup; 3100 block_stack->data.block.cleanup_ptr 3101 = block_stack->next->data.block.cleanup_ptr; 3102 } 3103} 3104 3105/* True if we are currently emitting insns in an area of output code 3106 that is controlled by a conditional expression. This is used by 3107 the cleanup handling code to generate conditional cleanup actions. */ 3108 3109int 3110conditional_context () 3111{ 3112 return block_stack && block_stack->data.block.conditional_code; 3113} 3114 3115/* Mark top block of block_stack as not for an implicit binding for an 3116 exception region. This is only ever done by expand_eh_region_end 3117 to let expand_end_bindings know that it is being called explicitly 3118 to end the binding layer for just the binding layer associated with 3119 the exception region, otherwise expand_end_bindings would try and 3120 end all implicit binding layers for exceptions regions, and then 3121 one normal binding layer. */ 3122 3123void 3124mark_block_as_not_eh_region () 3125{ 3126 block_stack->data.block.exception_region = 0; 3127} 3128 3129/* True if the top block of block_stack was marked as for an exception 3130 region by mark_block_as_eh_region. */ 3131 3132int 3133is_eh_region () 3134{ 3135 return block_stack && block_stack->data.block.exception_region; 3136} 3137 3138/* Given a pointer to a BLOCK node, save a pointer to the most recently 3139 generated NOTE_INSN_BLOCK_END in the BLOCK_END_NOTE field of the given 3140 BLOCK node. */ 3141 3142void 3143remember_end_note (block) 3144 register tree block; 3145{ 3146 BLOCK_END_NOTE (block) = last_block_end_note; 3147 last_block_end_note = NULL_RTX; 3148} 3149 3150/* Emit a handler label for a nonlocal goto handler. 3151 Also emit code to store the handler label in SLOT before BEFORE_INSN. */ 3152 3153static rtx 3154expand_nl_handler_label (slot, before_insn) 3155 rtx slot, before_insn; 3156{ 3157 rtx insns; 3158 rtx handler_label = gen_label_rtx (); 3159 3160 /* Don't let jump_optimize delete the handler. */ 3161 LABEL_PRESERVE_P (handler_label) = 1; 3162 3163 start_sequence (); 3164 emit_move_insn (slot, gen_rtx_LABEL_REF (Pmode, handler_label)); 3165 insns = get_insns (); 3166 end_sequence (); 3167 emit_insns_before (insns, before_insn); 3168 3169 emit_label (handler_label); 3170 3171 return handler_label; 3172} 3173 3174/* Emit code to restore vital registers at the beginning of a nonlocal goto 3175 handler. */ 3176static void 3177expand_nl_goto_receiver () 3178{ 3179#ifdef HAVE_nonlocal_goto 3180 if (! HAVE_nonlocal_goto) 3181#endif 3182 /* First adjust our frame pointer to its actual value. It was 3183 previously set to the start of the virtual area corresponding to 3184 the stacked variables when we branched here and now needs to be 3185 adjusted to the actual hardware fp value. 3186 3187 Assignments are to virtual registers are converted by 3188 instantiate_virtual_regs into the corresponding assignment 3189 to the underlying register (fp in this case) that makes 3190 the original assignment true. 3191 So the following insn will actually be 3192 decrementing fp by STARTING_FRAME_OFFSET. */ 3193 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx); 3194 3195#if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM 3196 if (fixed_regs[ARG_POINTER_REGNUM]) 3197 { 3198#ifdef ELIMINABLE_REGS 3199 /* If the argument pointer can be eliminated in favor of the 3200 frame pointer, we don't need to restore it. We assume here 3201 that if such an elimination is present, it can always be used. 3202 This is the case on all known machines; if we don't make this 3203 assumption, we do unnecessary saving on many machines. */ 3204 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS; 3205 size_t i; 3206 3207 for (i = 0; i < sizeof elim_regs / sizeof elim_regs[0]; i++) 3208 if (elim_regs[i].from == ARG_POINTER_REGNUM 3209 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM) 3210 break; 3211 3212 if (i == sizeof elim_regs / sizeof elim_regs [0]) 3213#endif 3214 { 3215 /* Now restore our arg pointer from the address at which it 3216 was saved in our stack frame. 3217 If there hasn't be space allocated for it yet, make 3218 some now. */ 3219 if (arg_pointer_save_area == 0) 3220 arg_pointer_save_area 3221 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0); 3222 emit_move_insn (virtual_incoming_args_rtx, 3223 /* We need a pseudo here, or else 3224 instantiate_virtual_regs_1 complains. */ 3225 copy_to_reg (arg_pointer_save_area)); 3226 } 3227 } 3228#endif 3229 3230#ifdef HAVE_nonlocal_goto_receiver 3231 if (HAVE_nonlocal_goto_receiver) 3232 emit_insn (gen_nonlocal_goto_receiver ()); 3233#endif 3234} 3235 3236/* Make handlers for nonlocal gotos taking place in the function calls in 3237 block THISBLOCK. */ 3238 3239static void 3240expand_nl_goto_receivers (thisblock) 3241 struct nesting *thisblock; 3242{ 3243 tree link; 3244 rtx afterward = gen_label_rtx (); 3245 rtx insns, slot; 3246 rtx label_list; 3247 int any_invalid; 3248 3249 /* Record the handler address in the stack slot for that purpose, 3250 during this block, saving and restoring the outer value. */ 3251 if (thisblock->next != 0) 3252 for (slot = nonlocal_goto_handler_slots; slot; slot = XEXP (slot, 1)) 3253 { 3254 rtx save_receiver = gen_reg_rtx (Pmode); 3255 emit_move_insn (XEXP (slot, 0), save_receiver); 3256 3257 start_sequence (); 3258 emit_move_insn (save_receiver, XEXP (slot, 0)); 3259 insns = get_insns (); 3260 end_sequence (); 3261 emit_insns_before (insns, thisblock->data.block.first_insn); 3262 } 3263 3264 /* Jump around the handlers; they run only when specially invoked. */ 3265 emit_jump (afterward); 3266 3267 /* Make a separate handler for each label. */ 3268 link = nonlocal_labels; 3269 slot = nonlocal_goto_handler_slots; 3270 label_list = NULL_RTX; 3271 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1)) 3272 /* Skip any labels we shouldn't be able to jump to from here, 3273 we generate one special handler for all of them below which just calls 3274 abort. */ 3275 if (! DECL_TOO_LATE (TREE_VALUE (link))) 3276 { 3277 rtx lab; 3278 lab = expand_nl_handler_label (XEXP (slot, 0), 3279 thisblock->data.block.first_insn); 3280 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list); 3281 3282 expand_nl_goto_receiver (); 3283 3284 /* Jump to the "real" nonlocal label. */ 3285 expand_goto (TREE_VALUE (link)); 3286 } 3287 3288 /* A second pass over all nonlocal labels; this time we handle those 3289 we should not be able to jump to at this point. */ 3290 link = nonlocal_labels; 3291 slot = nonlocal_goto_handler_slots; 3292 any_invalid = 0; 3293 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1)) 3294 if (DECL_TOO_LATE (TREE_VALUE (link))) 3295 { 3296 rtx lab; 3297 lab = expand_nl_handler_label (XEXP (slot, 0), 3298 thisblock->data.block.first_insn); 3299 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list); 3300 any_invalid = 1; 3301 } 3302 3303 if (any_invalid) 3304 { 3305 expand_nl_goto_receiver (); 3306 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "abort"), 0, 3307 VOIDmode, 0); 3308 emit_barrier (); 3309 } 3310 3311 nonlocal_goto_handler_labels = label_list; 3312 emit_label (afterward); 3313} 3314 3315/* Generate RTL code to terminate a binding contour. 3316 3317 VARS is the chain of VAR_DECL nodes for the variables bound in this 3318 contour. There may actually be other nodes in this chain, but any 3319 nodes other than VAR_DECLS are ignored. 3320 3321 MARK_ENDS is nonzero if we should put a note at the beginning 3322 and end of this binding contour. 3323 3324 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour. 3325 (That is true automatically if the contour has a saved stack level.) */ 3326 3327void 3328expand_end_bindings (vars, mark_ends, dont_jump_in) 3329 tree vars; 3330 int mark_ends; 3331 int dont_jump_in; 3332{ 3333 register struct nesting *thisblock; 3334 register tree decl; 3335 3336 while (block_stack->data.block.exception_region) 3337 { 3338 /* Because we don't need or want a new temporary level and 3339 because we didn't create one in expand_eh_region_start, 3340 create a fake one now to avoid removing one in 3341 expand_end_bindings. */ 3342 push_temp_slots (); 3343 3344 block_stack->data.block.exception_region = 0; 3345 3346 expand_end_bindings (NULL_TREE, 0, 0); 3347 } 3348 3349 /* Since expand_eh_region_start does an expand_start_bindings, we 3350 have to first end all the bindings that were created by 3351 expand_eh_region_start. */ 3352 3353 thisblock = block_stack; 3354 3355 if (warn_unused) 3356 for (decl = vars; decl; decl = TREE_CHAIN (decl)) 3357 if (TREE_CODE (decl) == VAR_DECL 3358 && ! TREE_USED (decl) 3359 && ! DECL_IN_SYSTEM_HEADER (decl) 3360 && DECL_NAME (decl) && ! DECL_ARTIFICIAL (decl)) 3361 warning_with_decl (decl, "unused variable `%s'"); 3362 3363 if (thisblock->exit_label) 3364 { 3365 do_pending_stack_adjust (); 3366 emit_label (thisblock->exit_label); 3367 } 3368 3369 /* If necessary, make handlers for nonlocal gotos taking 3370 place in the function calls in this block. */ 3371 if (function_call_count != thisblock->data.block.function_call_count 3372 && nonlocal_labels 3373 /* Make handler for outermost block 3374 if there were any nonlocal gotos to this function. */ 3375 && (thisblock->next == 0 ? current_function_has_nonlocal_label 3376 /* Make handler for inner block if it has something 3377 special to do when you jump out of it. */ 3378 : (thisblock->data.block.cleanups != 0 3379 || thisblock->data.block.stack_level != 0))) 3380 expand_nl_goto_receivers (thisblock); 3381 3382 /* Don't allow jumping into a block that has a stack level. 3383 Cleanups are allowed, though. */ 3384 if (dont_jump_in 3385 || thisblock->data.block.stack_level != 0) 3386 { 3387 struct label_chain *chain; 3388 3389 /* Any labels in this block are no longer valid to go to. 3390 Mark them to cause an error message. */ 3391 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next) 3392 { 3393 DECL_TOO_LATE (chain->label) = 1; 3394 /* If any goto without a fixup came to this label, 3395 that must be an error, because gotos without fixups 3396 come from outside all saved stack-levels. */ 3397 if (TREE_ADDRESSABLE (chain->label)) 3398 error_with_decl (chain->label, 3399 "label `%s' used before containing binding contour"); 3400 } 3401 } 3402 3403 /* Restore stack level in effect before the block 3404 (only if variable-size objects allocated). */ 3405 /* Perform any cleanups associated with the block. */ 3406 3407 if (thisblock->data.block.stack_level != 0 3408 || thisblock->data.block.cleanups != 0) 3409 { 3410 /* Only clean up here if this point can actually be reached. */ 3411 int reachable = GET_CODE (get_last_insn ()) != BARRIER; 3412 3413 /* Don't let cleanups affect ({...}) constructs. */ 3414 int old_expr_stmts_for_value = expr_stmts_for_value; 3415 rtx old_last_expr_value = last_expr_value; 3416 tree old_last_expr_type = last_expr_type; 3417 expr_stmts_for_value = 0; 3418 3419 /* Do the cleanups. */ 3420 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable); 3421 if (reachable) 3422 do_pending_stack_adjust (); 3423 3424 expr_stmts_for_value = old_expr_stmts_for_value; 3425 last_expr_value = old_last_expr_value; 3426 last_expr_type = old_last_expr_type; 3427 3428 /* Restore the stack level. */ 3429 3430 if (reachable && thisblock->data.block.stack_level != 0) 3431 { 3432 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION, 3433 thisblock->data.block.stack_level, NULL_RTX); 3434 if (nonlocal_goto_handler_slots != 0) 3435 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level, 3436 NULL_RTX); 3437 } 3438 3439 /* Any gotos out of this block must also do these things. 3440 Also report any gotos with fixups that came to labels in this 3441 level. */ 3442 fixup_gotos (thisblock, 3443 thisblock->data.block.stack_level, 3444 thisblock->data.block.cleanups, 3445 thisblock->data.block.first_insn, 3446 dont_jump_in); 3447 } 3448 3449 /* Mark the beginning and end of the scope if requested. 3450 We do this now, after running cleanups on the variables 3451 just going out of scope, so they are in scope for their cleanups. */ 3452 3453 if (mark_ends) 3454 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END); 3455 else 3456 /* Get rid of the beginning-mark if we don't make an end-mark. */ 3457 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED; 3458 3459 /* If doing stupid register allocation, make sure lives of all 3460 register variables declared here extend thru end of scope. */ 3461 3462 if (obey_regdecls) 3463 for (decl = vars; decl; decl = TREE_CHAIN (decl)) 3464 if (TREE_CODE (decl) == VAR_DECL && DECL_RTL (decl)) 3465 use_variable (DECL_RTL (decl)); 3466 3467 /* Restore the temporary level of TARGET_EXPRs. */ 3468 target_temp_slot_level = thisblock->data.block.target_temp_slot_level; 3469 3470 /* Restore block_stack level for containing block. */ 3471 3472 stack_block_stack = thisblock->data.block.innermost_stack_block; 3473 POPSTACK (block_stack); 3474 3475 /* Pop the stack slot nesting and free any slots at this level. */ 3476 pop_temp_slots (); 3477} 3478 3479/* Generate RTL for the automatic variable declaration DECL. 3480 (Other kinds of declarations are simply ignored if seen here.) */ 3481 3482void 3483expand_decl (decl) 3484 register tree decl; 3485{ 3486 struct nesting *thisblock = block_stack; 3487 tree type; 3488 3489 type = TREE_TYPE (decl); 3490 3491 /* Only automatic variables need any expansion done. 3492 Static and external variables, and external functions, 3493 will be handled by `assemble_variable' (called from finish_decl). 3494 TYPE_DECL and CONST_DECL require nothing. 3495 PARM_DECLs are handled in `assign_parms'. */ 3496 3497 if (TREE_CODE (decl) != VAR_DECL) 3498 return; 3499 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl)) 3500 return; 3501 3502 /* Create the RTL representation for the variable. */ 3503 3504 if (type == error_mark_node) 3505 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, const0_rtx); 3506 else if (DECL_SIZE (decl) == 0) 3507 /* Variable with incomplete type. */ 3508 { 3509 if (DECL_INITIAL (decl) == 0) 3510 /* Error message was already done; now avoid a crash. */ 3511 DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1); 3512 else 3513 /* An initializer is going to decide the size of this array. 3514 Until we know the size, represent its address with a reg. */ 3515 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, gen_reg_rtx (Pmode)); 3516 MEM_SET_IN_STRUCT_P (DECL_RTL (decl), AGGREGATE_TYPE_P (type)); 3517 } 3518 else if (DECL_MODE (decl) != BLKmode 3519 /* If -ffloat-store, don't put explicit float vars 3520 into regs. */ 3521 && !(flag_float_store 3522 && TREE_CODE (type) == REAL_TYPE) 3523 && ! TREE_THIS_VOLATILE (decl) 3524 && ! TREE_ADDRESSABLE (decl) 3525 && (DECL_REGISTER (decl) || ! obey_regdecls) 3526 /* if -fcheck-memory-usage, check all variables. */ 3527 && ! current_function_check_memory_usage) 3528 { 3529 /* Automatic variable that can go in a register. */ 3530 int unsignedp = TREE_UNSIGNED (type); 3531 enum machine_mode reg_mode 3532 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0); 3533 3534 DECL_RTL (decl) = gen_reg_rtx (reg_mode); 3535 mark_user_reg (DECL_RTL (decl)); 3536 3537 if (POINTER_TYPE_P (type)) 3538 mark_reg_pointer (DECL_RTL (decl), 3539 (TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))) 3540 / BITS_PER_UNIT)); 3541 } 3542 3543 else if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST 3544 && ! (flag_stack_check && ! STACK_CHECK_BUILTIN 3545 && (TREE_INT_CST_HIGH (DECL_SIZE (decl)) != 0 3546 || (TREE_INT_CST_LOW (DECL_SIZE (decl)) 3547 > STACK_CHECK_MAX_VAR_SIZE * BITS_PER_UNIT)))) 3548 { 3549 /* Variable of fixed size that goes on the stack. */ 3550 rtx oldaddr = 0; 3551 rtx addr; 3552 3553 /* If we previously made RTL for this decl, it must be an array 3554 whose size was determined by the initializer. 3555 The old address was a register; set that register now 3556 to the proper address. */ 3557 if (DECL_RTL (decl) != 0) 3558 { 3559 if (GET_CODE (DECL_RTL (decl)) != MEM 3560 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG) 3561 abort (); 3562 oldaddr = XEXP (DECL_RTL (decl), 0); 3563 } 3564 3565 DECL_RTL (decl) = assign_temp (TREE_TYPE (decl), 1, 1, 1); 3566 MEM_SET_IN_STRUCT_P (DECL_RTL (decl), 3567 AGGREGATE_TYPE_P (TREE_TYPE (decl))); 3568 3569 /* Set alignment we actually gave this decl. */ 3570 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT 3571 : GET_MODE_BITSIZE (DECL_MODE (decl))); 3572 3573 if (oldaddr) 3574 { 3575 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr); 3576 if (addr != oldaddr) 3577 emit_move_insn (oldaddr, addr); 3578 } 3579 3580 /* If this is a memory ref that contains aggregate components, 3581 mark it as such for cse and loop optimize. */ 3582 MEM_SET_IN_STRUCT_P (DECL_RTL (decl), 3583 AGGREGATE_TYPE_P (TREE_TYPE (decl))); 3584#if 0 3585 /* If this is in memory because of -ffloat-store, 3586 set the volatile bit, to prevent optimizations from 3587 undoing the effects. */ 3588 if (flag_float_store && TREE_CODE (type) == REAL_TYPE) 3589 MEM_VOLATILE_P (DECL_RTL (decl)) = 1; 3590#endif 3591 3592 MEM_ALIAS_SET (DECL_RTL (decl)) = get_alias_set (decl); 3593 } 3594 else 3595 /* Dynamic-size object: must push space on the stack. */ 3596 { 3597 rtx address, size; 3598 3599 /* Record the stack pointer on entry to block, if have 3600 not already done so. */ 3601 if (thisblock->data.block.stack_level == 0) 3602 { 3603 do_pending_stack_adjust (); 3604 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION, 3605 &thisblock->data.block.stack_level, 3606 thisblock->data.block.first_insn); 3607 stack_block_stack = thisblock; 3608 } 3609 3610 /* Compute the variable's size, in bytes. */ 3611 size = expand_expr (size_binop (CEIL_DIV_EXPR, 3612 DECL_SIZE (decl), 3613 size_int (BITS_PER_UNIT)), 3614 NULL_RTX, VOIDmode, 0); 3615 free_temp_slots (); 3616 3617 /* Allocate space on the stack for the variable. Note that 3618 DECL_ALIGN says how the variable is to be aligned and we 3619 cannot use it to conclude anything about the alignment of 3620 the size. */ 3621 address = allocate_dynamic_stack_space (size, NULL_RTX, 3622 TYPE_ALIGN (TREE_TYPE (decl))); 3623 3624 /* Reference the variable indirect through that rtx. */ 3625 DECL_RTL (decl) = gen_rtx_MEM (DECL_MODE (decl), address); 3626 3627 /* If this is a memory ref that contains aggregate components, 3628 mark it as such for cse and loop optimize. */ 3629 MEM_SET_IN_STRUCT_P (DECL_RTL (decl), 3630 AGGREGATE_TYPE_P (TREE_TYPE (decl))); 3631 3632 /* Indicate the alignment we actually gave this variable. */ 3633#ifdef STACK_BOUNDARY 3634 DECL_ALIGN (decl) = STACK_BOUNDARY; 3635#else 3636 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT; 3637#endif 3638 } 3639 3640 if (TREE_THIS_VOLATILE (decl)) 3641 MEM_VOLATILE_P (DECL_RTL (decl)) = 1; 3642#if 0 /* A variable is not necessarily unchanging 3643 just because it is const. RTX_UNCHANGING_P 3644 means no change in the function, 3645 not merely no change in the variable's scope. 3646 It is correct to set RTX_UNCHANGING_P if the variable's scope 3647 is the whole function. There's no convenient way to test that. */ 3648 if (TREE_READONLY (decl)) 3649 RTX_UNCHANGING_P (DECL_RTL (decl)) = 1; 3650#endif 3651 3652 /* If doing stupid register allocation, make sure life of any 3653 register variable starts here, at the start of its scope. */ 3654 3655 if (obey_regdecls) 3656 use_variable (DECL_RTL (decl)); 3657} 3658 3659 3660 3661/* Emit code to perform the initialization of a declaration DECL. */ 3662 3663void 3664expand_decl_init (decl) 3665 tree decl; 3666{ 3667 int was_used = TREE_USED (decl); 3668 3669 /* If this is a CONST_DECL, we don't have to generate any code, but 3670 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL 3671 to be set while in the obstack containing the constant. If we don't 3672 do this, we can lose if we have functions nested three deep and the middle 3673 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while 3674 the innermost function is the first to expand that STRING_CST. */ 3675 if (TREE_CODE (decl) == CONST_DECL) 3676 { 3677 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl))) 3678 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode, 3679 EXPAND_INITIALIZER); 3680 return; 3681 } 3682 3683 if (TREE_STATIC (decl)) 3684 return; 3685 3686 /* Compute and store the initial value now. */ 3687 3688 if (DECL_INITIAL (decl) == error_mark_node) 3689 { 3690 enum tree_code code = TREE_CODE (TREE_TYPE (decl)); 3691 3692 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE 3693 || code == POINTER_TYPE || code == REFERENCE_TYPE) 3694 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node), 3695 0, 0); 3696 emit_queue (); 3697 } 3698 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST) 3699 { 3700 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl)); 3701 expand_assignment (decl, DECL_INITIAL (decl), 0, 0); 3702 emit_queue (); 3703 } 3704 3705 /* Don't let the initialization count as "using" the variable. */ 3706 TREE_USED (decl) = was_used; 3707 3708 /* Free any temporaries we made while initializing the decl. */ 3709 preserve_temp_slots (NULL_RTX); 3710 free_temp_slots (); 3711} 3712 3713/* CLEANUP is an expression to be executed at exit from this binding contour; 3714 for example, in C++, it might call the destructor for this variable. 3715 3716 We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the 3717 CLEANUP multiple times, and have the correct semantics. This 3718 happens in exception handling, for gotos, returns, breaks that 3719 leave the current scope. 3720 3721 If CLEANUP is nonzero and DECL is zero, we record a cleanup 3722 that is not associated with any particular variable. */ 3723 3724int 3725expand_decl_cleanup (decl, cleanup) 3726 tree decl, cleanup; 3727{ 3728 struct nesting *thisblock = block_stack; 3729 3730 /* Error if we are not in any block. */ 3731 if (thisblock == 0) 3732 return 0; 3733 3734 /* Record the cleanup if there is one. */ 3735 3736 if (cleanup != 0) 3737 { 3738 tree t; 3739 rtx seq; 3740 tree *cleanups = &thisblock->data.block.cleanups; 3741 int cond_context = conditional_context (); 3742 3743 if (cond_context) 3744 { 3745 rtx flag = gen_reg_rtx (word_mode); 3746 rtx set_flag_0; 3747 tree cond; 3748 3749 start_sequence (); 3750 emit_move_insn (flag, const0_rtx); 3751 set_flag_0 = get_insns (); 3752 end_sequence (); 3753 3754 thisblock->data.block.last_unconditional_cleanup 3755 = emit_insns_after (set_flag_0, 3756 thisblock->data.block.last_unconditional_cleanup); 3757 3758 emit_move_insn (flag, const1_rtx); 3759 3760 /* All cleanups must be on the function_obstack. */ 3761 push_obstacks_nochange (); 3762 resume_temporary_allocation (); 3763 3764 cond = build_decl (VAR_DECL, NULL_TREE, type_for_mode (word_mode, 1)); 3765 DECL_RTL (cond) = flag; 3766 3767 /* Conditionalize the cleanup. */ 3768 cleanup = build (COND_EXPR, void_type_node, 3769 truthvalue_conversion (cond), 3770 cleanup, integer_zero_node); 3771 cleanup = fold (cleanup); 3772 3773 pop_obstacks (); 3774 3775 cleanups = thisblock->data.block.cleanup_ptr; 3776 } 3777 3778 /* All cleanups must be on the function_obstack. */ 3779 push_obstacks_nochange (); 3780 resume_temporary_allocation (); 3781 cleanup = unsave_expr (cleanup); 3782 pop_obstacks (); 3783 3784 t = *cleanups = temp_tree_cons (decl, cleanup, *cleanups); 3785 3786 if (! cond_context) 3787 /* If this block has a cleanup, it belongs in stack_block_stack. */ 3788 stack_block_stack = thisblock; 3789 3790 if (cond_context) 3791 { 3792 start_sequence (); 3793 } 3794 3795 /* If this was optimized so that there is no exception region for the 3796 cleanup, then mark the TREE_LIST node, so that we can later tell 3797 if we need to call expand_eh_region_end. */ 3798 if (! using_eh_for_cleanups_p 3799 || expand_eh_region_start_tree (decl, cleanup)) 3800 TREE_ADDRESSABLE (t) = 1; 3801 /* If that started a new EH region, we're in a new block. */ 3802 thisblock = block_stack; 3803 3804 if (cond_context) 3805 { 3806 seq = get_insns (); 3807 end_sequence (); 3808 if (seq) 3809 thisblock->data.block.last_unconditional_cleanup 3810 = emit_insns_after (seq, 3811 thisblock->data.block.last_unconditional_cleanup); 3812 } 3813 else 3814 { 3815 thisblock->data.block.last_unconditional_cleanup 3816 = get_last_insn (); 3817 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups; 3818 } 3819 } 3820 return 1; 3821} 3822 3823/* Like expand_decl_cleanup, but suppress generating an exception handler 3824 to perform the cleanup. */ 3825 3826int 3827expand_decl_cleanup_no_eh (decl, cleanup) 3828 tree decl, cleanup; 3829{ 3830 int save_eh = using_eh_for_cleanups_p; 3831 int result; 3832 3833 using_eh_for_cleanups_p = 0; 3834 result = expand_decl_cleanup (decl, cleanup); 3835 using_eh_for_cleanups_p = save_eh; 3836 3837 return result; 3838} 3839 3840/* Arrange for the top element of the dynamic cleanup chain to be 3841 popped if we exit the current binding contour. DECL is the 3842 associated declaration, if any, otherwise NULL_TREE. If the 3843 current contour is left via an exception, then __sjthrow will pop 3844 the top element off the dynamic cleanup chain. The code that 3845 avoids doing the action we push into the cleanup chain in the 3846 exceptional case is contained in expand_cleanups. 3847 3848 This routine is only used by expand_eh_region_start, and that is 3849 the only way in which an exception region should be started. This 3850 routine is only used when using the setjmp/longjmp codegen method 3851 for exception handling. */ 3852 3853int 3854expand_dcc_cleanup (decl) 3855 tree decl; 3856{ 3857 struct nesting *thisblock = block_stack; 3858 tree cleanup; 3859 3860 /* Error if we are not in any block. */ 3861 if (thisblock == 0) 3862 return 0; 3863 3864 /* Record the cleanup for the dynamic handler chain. */ 3865 3866 /* All cleanups must be on the function_obstack. */ 3867 push_obstacks_nochange (); 3868 resume_temporary_allocation (); 3869 cleanup = make_node (POPDCC_EXPR); 3870 pop_obstacks (); 3871 3872 /* Add the cleanup in a manner similar to expand_decl_cleanup. */ 3873 thisblock->data.block.cleanups 3874 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups); 3875 3876 /* If this block has a cleanup, it belongs in stack_block_stack. */ 3877 stack_block_stack = thisblock; 3878 return 1; 3879} 3880 3881/* Arrange for the top element of the dynamic handler chain to be 3882 popped if we exit the current binding contour. DECL is the 3883 associated declaration, if any, otherwise NULL_TREE. If the current 3884 contour is left via an exception, then __sjthrow will pop the top 3885 element off the dynamic handler chain. The code that avoids doing 3886 the action we push into the handler chain in the exceptional case 3887 is contained in expand_cleanups. 3888 3889 This routine is only used by expand_eh_region_start, and that is 3890 the only way in which an exception region should be started. This 3891 routine is only used when using the setjmp/longjmp codegen method 3892 for exception handling. */ 3893 3894int 3895expand_dhc_cleanup (decl) 3896 tree decl; 3897{ 3898 struct nesting *thisblock = block_stack; 3899 tree cleanup; 3900 3901 /* Error if we are not in any block. */ 3902 if (thisblock == 0) 3903 return 0; 3904 3905 /* Record the cleanup for the dynamic handler chain. */ 3906 3907 /* All cleanups must be on the function_obstack. */ 3908 push_obstacks_nochange (); 3909 resume_temporary_allocation (); 3910 cleanup = make_node (POPDHC_EXPR); 3911 pop_obstacks (); 3912 3913 /* Add the cleanup in a manner similar to expand_decl_cleanup. */ 3914 thisblock->data.block.cleanups 3915 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups); 3916 3917 /* If this block has a cleanup, it belongs in stack_block_stack. */ 3918 stack_block_stack = thisblock; 3919 return 1; 3920} 3921 3922/* DECL is an anonymous union. CLEANUP is a cleanup for DECL. 3923 DECL_ELTS is the list of elements that belong to DECL's type. 3924 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */ 3925 3926void 3927expand_anon_union_decl (decl, cleanup, decl_elts) 3928 tree decl, cleanup, decl_elts; 3929{ 3930 struct nesting *thisblock = block_stack; 3931 rtx x; 3932 3933 expand_decl (decl); 3934 expand_decl_cleanup (decl, cleanup); 3935 x = DECL_RTL (decl); 3936 3937 while (decl_elts) 3938 { 3939 tree decl_elt = TREE_VALUE (decl_elts); 3940 tree cleanup_elt = TREE_PURPOSE (decl_elts); 3941 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt)); 3942 3943 /* Propagate the union's alignment to the elements. */ 3944 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl); 3945 3946 /* If the element has BLKmode and the union doesn't, the union is 3947 aligned such that the element doesn't need to have BLKmode, so 3948 change the element's mode to the appropriate one for its size. */ 3949 if (mode == BLKmode && DECL_MODE (decl) != BLKmode) 3950 DECL_MODE (decl_elt) = mode 3951 = mode_for_size (TREE_INT_CST_LOW (DECL_SIZE (decl_elt)), 3952 MODE_INT, 1); 3953 3954 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we 3955 instead create a new MEM rtx with the proper mode. */ 3956 if (GET_CODE (x) == MEM) 3957 { 3958 if (mode == GET_MODE (x)) 3959 DECL_RTL (decl_elt) = x; 3960 else 3961 { 3962 DECL_RTL (decl_elt) = gen_rtx_MEM (mode, copy_rtx (XEXP (x, 0))); 3963 MEM_COPY_ATTRIBUTES (DECL_RTL (decl_elt), x); 3964 RTX_UNCHANGING_P (DECL_RTL (decl_elt)) = RTX_UNCHANGING_P (x); 3965 } 3966 } 3967 else if (GET_CODE (x) == REG) 3968 { 3969 if (mode == GET_MODE (x)) 3970 DECL_RTL (decl_elt) = x; 3971 else 3972 DECL_RTL (decl_elt) = gen_rtx_SUBREG (mode, x, 0); 3973 } 3974 else 3975 abort (); 3976 3977 /* Record the cleanup if there is one. */ 3978 3979 if (cleanup != 0) 3980 thisblock->data.block.cleanups 3981 = temp_tree_cons (decl_elt, cleanup_elt, 3982 thisblock->data.block.cleanups); 3983 3984 decl_elts = TREE_CHAIN (decl_elts); 3985 } 3986} 3987 3988/* Expand a list of cleanups LIST. 3989 Elements may be expressions or may be nested lists. 3990 3991 If DONT_DO is nonnull, then any list-element 3992 whose TREE_PURPOSE matches DONT_DO is omitted. 3993 This is sometimes used to avoid a cleanup associated with 3994 a value that is being returned out of the scope. 3995 3996 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup 3997 goto and handle protection regions specially in that case. 3998 3999 If REACHABLE, we emit code, otherwise just inform the exception handling 4000 code about this finalization. */ 4001 4002static void 4003expand_cleanups (list, dont_do, in_fixup, reachable) 4004 tree list; 4005 tree dont_do; 4006 int in_fixup; 4007 int reachable; 4008{ 4009 tree tail; 4010 for (tail = list; tail; tail = TREE_CHAIN (tail)) 4011 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do) 4012 { 4013 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST) 4014 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable); 4015 else 4016 { 4017 if (! in_fixup) 4018 { 4019 tree cleanup = TREE_VALUE (tail); 4020 4021 /* See expand_d{h,c}c_cleanup for why we avoid this. */ 4022 if (TREE_CODE (cleanup) != POPDHC_EXPR 4023 && TREE_CODE (cleanup) != POPDCC_EXPR 4024 /* See expand_eh_region_start_tree for this case. */ 4025 && ! TREE_ADDRESSABLE (tail)) 4026 { 4027 cleanup = protect_with_terminate (cleanup); 4028 expand_eh_region_end (cleanup); 4029 } 4030 } 4031 4032 if (reachable) 4033 { 4034 /* Cleanups may be run multiple times. For example, 4035 when exiting a binding contour, we expand the 4036 cleanups associated with that contour. When a goto 4037 within that binding contour has a target outside that 4038 contour, it will expand all cleanups from its scope to 4039 the target. Though the cleanups are expanded multiple 4040 times, the control paths are non-overlapping so the 4041 cleanups will not be executed twice. */ 4042 4043 /* We may need to protect fixups with rethrow regions. */ 4044 int protect = (in_fixup && ! TREE_ADDRESSABLE (tail)); 4045 4046 if (protect) 4047 expand_fixup_region_start (); 4048 4049 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0); 4050 if (protect) 4051 expand_fixup_region_end (TREE_VALUE (tail)); 4052 free_temp_slots (); 4053 } 4054 } 4055 } 4056} 4057 4058/* Mark when the context we are emitting RTL for as a conditional 4059 context, so that any cleanup actions we register with 4060 expand_decl_init will be properly conditionalized when those 4061 cleanup actions are later performed. Must be called before any 4062 expression (tree) is expanded that is within a conditional context. */ 4063 4064void 4065start_cleanup_deferral () 4066{ 4067 /* block_stack can be NULL if we are inside the parameter list. It is 4068 OK to do nothing, because cleanups aren't possible here. */ 4069 if (block_stack) 4070 ++block_stack->data.block.conditional_code; 4071} 4072 4073/* Mark the end of a conditional region of code. Because cleanup 4074 deferrals may be nested, we may still be in a conditional region 4075 after we end the currently deferred cleanups, only after we end all 4076 deferred cleanups, are we back in unconditional code. */ 4077 4078void 4079end_cleanup_deferral () 4080{ 4081 /* block_stack can be NULL if we are inside the parameter list. It is 4082 OK to do nothing, because cleanups aren't possible here. */ 4083 if (block_stack) 4084 --block_stack->data.block.conditional_code; 4085} 4086 4087/* Move all cleanups from the current block_stack 4088 to the containing block_stack, where they are assumed to 4089 have been created. If anything can cause a temporary to 4090 be created, but not expanded for more than one level of 4091 block_stacks, then this code will have to change. */ 4092 4093void 4094move_cleanups_up () 4095{ 4096 struct nesting *block = block_stack; 4097 struct nesting *outer = block->next; 4098 4099 outer->data.block.cleanups 4100 = chainon (block->data.block.cleanups, 4101 outer->data.block.cleanups); 4102 block->data.block.cleanups = 0; 4103} 4104 4105tree 4106last_cleanup_this_contour () 4107{ 4108 if (block_stack == 0) 4109 return 0; 4110 4111 return block_stack->data.block.cleanups; 4112} 4113 4114/* Return 1 if there are any pending cleanups at this point. 4115 If THIS_CONTOUR is nonzero, check the current contour as well. 4116 Otherwise, look only at the contours that enclose this one. */ 4117 4118int 4119any_pending_cleanups (this_contour) 4120 int this_contour; 4121{ 4122 struct nesting *block; 4123 4124 if (block_stack == 0) 4125 return 0; 4126 4127 if (this_contour && block_stack->data.block.cleanups != NULL) 4128 return 1; 4129 if (block_stack->data.block.cleanups == 0 4130 && block_stack->data.block.outer_cleanups == 0) 4131 return 0; 4132 4133 for (block = block_stack->next; block; block = block->next) 4134 if (block->data.block.cleanups != 0) 4135 return 1; 4136 4137 return 0; 4138} 4139 4140/* Enter a case (Pascal) or switch (C) statement. 4141 Push a block onto case_stack and nesting_stack 4142 to accumulate the case-labels that are seen 4143 and to record the labels generated for the statement. 4144 4145 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt. 4146 Otherwise, this construct is transparent for `exit_something'. 4147 4148 EXPR is the index-expression to be dispatched on. 4149 TYPE is its nominal type. We could simply convert EXPR to this type, 4150 but instead we take short cuts. */ 4151 4152void 4153expand_start_case (exit_flag, expr, type, printname) 4154 int exit_flag; 4155 tree expr; 4156 tree type; 4157 const char *printname; 4158{ 4159 register struct nesting *thiscase = ALLOC_NESTING (); 4160 4161 /* Make an entry on case_stack for the case we are entering. */ 4162 4163 thiscase->next = case_stack; 4164 thiscase->all = nesting_stack; 4165 thiscase->depth = ++nesting_depth; 4166 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0; 4167 thiscase->data.case_stmt.case_list = 0; 4168 thiscase->data.case_stmt.index_expr = expr; 4169 thiscase->data.case_stmt.nominal_type = type; 4170 thiscase->data.case_stmt.default_label = 0; 4171 thiscase->data.case_stmt.num_ranges = 0; 4172 thiscase->data.case_stmt.printname = printname; 4173 thiscase->data.case_stmt.line_number_status = force_line_numbers (); 4174 case_stack = thiscase; 4175 nesting_stack = thiscase; 4176 4177 do_pending_stack_adjust (); 4178 4179 /* Make sure case_stmt.start points to something that won't 4180 need any transformation before expand_end_case. */ 4181 if (GET_CODE (get_last_insn ()) != NOTE) 4182 emit_note (NULL_PTR, NOTE_INSN_DELETED); 4183 4184 thiscase->data.case_stmt.start = get_last_insn (); 4185 4186 start_cleanup_deferral (); 4187} 4188 4189 4190/* Start a "dummy case statement" within which case labels are invalid 4191 and are not connected to any larger real case statement. 4192 This can be used if you don't want to let a case statement jump 4193 into the middle of certain kinds of constructs. */ 4194 4195void 4196expand_start_case_dummy () 4197{ 4198 register struct nesting *thiscase = ALLOC_NESTING (); 4199 4200 /* Make an entry on case_stack for the dummy. */ 4201 4202 thiscase->next = case_stack; 4203 thiscase->all = nesting_stack; 4204 thiscase->depth = ++nesting_depth; 4205 thiscase->exit_label = 0; 4206 thiscase->data.case_stmt.case_list = 0; 4207 thiscase->data.case_stmt.start = 0; 4208 thiscase->data.case_stmt.nominal_type = 0; 4209 thiscase->data.case_stmt.default_label = 0; 4210 thiscase->data.case_stmt.num_ranges = 0; 4211 case_stack = thiscase; 4212 nesting_stack = thiscase; 4213 start_cleanup_deferral (); 4214} 4215 4216/* End a dummy case statement. */ 4217 4218void 4219expand_end_case_dummy () 4220{ 4221 end_cleanup_deferral (); 4222 POPSTACK (case_stack); 4223} 4224 4225/* Return the data type of the index-expression 4226 of the innermost case statement, or null if none. */ 4227 4228tree 4229case_index_expr_type () 4230{ 4231 if (case_stack) 4232 return TREE_TYPE (case_stack->data.case_stmt.index_expr); 4233 return 0; 4234} 4235 4236static void 4237check_seenlabel () 4238{ 4239 /* If this is the first label, warn if any insns have been emitted. */ 4240 if (case_stack->data.case_stmt.line_number_status >= 0) 4241 { 4242 rtx insn; 4243 4244 restore_line_number_status 4245 (case_stack->data.case_stmt.line_number_status); 4246 case_stack->data.case_stmt.line_number_status = -1; 4247 4248 for (insn = case_stack->data.case_stmt.start; 4249 insn; 4250 insn = NEXT_INSN (insn)) 4251 { 4252 if (GET_CODE (insn) == CODE_LABEL) 4253 break; 4254 if (GET_CODE (insn) != NOTE 4255 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE)) 4256 { 4257 do 4258 insn = PREV_INSN (insn); 4259 while (insn && (GET_CODE (insn) != NOTE || NOTE_LINE_NUMBER (insn) < 0)); 4260 4261 /* If insn is zero, then there must have been a syntax error. */ 4262 if (insn) 4263 warning_with_file_and_line (NOTE_SOURCE_FILE(insn), 4264 NOTE_LINE_NUMBER(insn), 4265 "unreachable code at beginning of %s", 4266 case_stack->data.case_stmt.printname); 4267 break; 4268 } 4269 } 4270 } 4271} 4272 4273/* Accumulate one case or default label inside a case or switch statement. 4274 VALUE is the value of the case (a null pointer, for a default label). 4275 The function CONVERTER, when applied to arguments T and V, 4276 converts the value V to the type T. 4277 4278 If not currently inside a case or switch statement, return 1 and do 4279 nothing. The caller will print a language-specific error message. 4280 If VALUE is a duplicate or overlaps, return 2 and do nothing 4281 except store the (first) duplicate node in *DUPLICATE. 4282 If VALUE is out of range, return 3 and do nothing. 4283 If we are jumping into the scope of a cleanup or var-sized array, return 5. 4284 Return 0 on success. 4285 4286 Extended to handle range statements. */ 4287 4288int 4289pushcase (value, converter, label, duplicate) 4290 register tree value; 4291 tree (*converter) PROTO((tree, tree)); 4292 register tree label; 4293 tree *duplicate; 4294{ 4295 tree index_type; 4296 tree nominal_type; 4297 4298 /* Fail if not inside a real case statement. */ 4299 if (! (case_stack && case_stack->data.case_stmt.start)) 4300 return 1; 4301 4302 if (stack_block_stack 4303 && stack_block_stack->depth > case_stack->depth) 4304 return 5; 4305 4306 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr); 4307 nominal_type = case_stack->data.case_stmt.nominal_type; 4308 4309 /* If the index is erroneous, avoid more problems: pretend to succeed. */ 4310 if (index_type == error_mark_node) 4311 return 0; 4312 4313 /* Convert VALUE to the type in which the comparisons are nominally done. */ 4314 if (value != 0) 4315 value = (*converter) (nominal_type, value); 4316 4317 check_seenlabel (); 4318 4319 /* Fail if this value is out of range for the actual type of the index 4320 (which may be narrower than NOMINAL_TYPE). */ 4321 if (value != 0 && ! int_fits_type_p (value, index_type)) 4322 return 3; 4323 4324 /* Fail if this is a duplicate or overlaps another entry. */ 4325 if (value == 0) 4326 { 4327 if (case_stack->data.case_stmt.default_label != 0) 4328 { 4329 *duplicate = case_stack->data.case_stmt.default_label; 4330 return 2; 4331 } 4332 case_stack->data.case_stmt.default_label = label; 4333 } 4334 else 4335 return add_case_node (value, value, label, duplicate); 4336 4337 expand_label (label); 4338 return 0; 4339} 4340 4341/* Like pushcase but this case applies to all values between VALUE1 and 4342 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest 4343 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range 4344 starts at VALUE1 and ends at the highest value of the index type. 4345 If both are NULL, this case applies to all values. 4346 4347 The return value is the same as that of pushcase but there is one 4348 additional error code: 4 means the specified range was empty. */ 4349 4350int 4351pushcase_range (value1, value2, converter, label, duplicate) 4352 register tree value1, value2; 4353 tree (*converter) PROTO((tree, tree)); 4354 register tree label; 4355 tree *duplicate; 4356{ 4357 tree index_type; 4358 tree nominal_type; 4359 4360 /* Fail if not inside a real case statement. */ 4361 if (! (case_stack && case_stack->data.case_stmt.start)) 4362 return 1; 4363 4364 if (stack_block_stack 4365 && stack_block_stack->depth > case_stack->depth) 4366 return 5; 4367 4368 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr); 4369 nominal_type = case_stack->data.case_stmt.nominal_type; 4370 4371 /* If the index is erroneous, avoid more problems: pretend to succeed. */ 4372 if (index_type == error_mark_node) 4373 return 0; 4374 4375 check_seenlabel (); 4376 4377 /* Convert VALUEs to type in which the comparisons are nominally done 4378 and replace any unspecified value with the corresponding bound. */ 4379 if (value1 == 0) 4380 value1 = TYPE_MIN_VALUE (index_type); 4381 if (value2 == 0) 4382 value2 = TYPE_MAX_VALUE (index_type); 4383 4384 /* Fail if the range is empty. Do this before any conversion since 4385 we want to allow out-of-range empty ranges. */ 4386 if (value2 && tree_int_cst_lt (value2, value1)) 4387 return 4; 4388 4389 value1 = (*converter) (nominal_type, value1); 4390 4391 /* If the max was unbounded, use the max of the nominal_type we are 4392 converting to. Do this after the < check above to suppress false 4393 positives. */ 4394 if (!value2) 4395 value2 = TYPE_MAX_VALUE (nominal_type); 4396 value2 = (*converter) (nominal_type, value2); 4397 4398 /* Fail if these values are out of range. */ 4399 if (TREE_CONSTANT_OVERFLOW (value1) 4400 || ! int_fits_type_p (value1, index_type)) 4401 return 3; 4402 4403 if (TREE_CONSTANT_OVERFLOW (value2) 4404 || ! int_fits_type_p (value2, index_type)) 4405 return 3; 4406 4407 return add_case_node (value1, value2, label, duplicate); 4408} 4409 4410/* Do the actual insertion of a case label for pushcase and pushcase_range 4411 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid 4412 slowdown for large switch statements. */ 4413 4414static int 4415add_case_node (low, high, label, duplicate) 4416 tree low, high; 4417 tree label; 4418 tree *duplicate; 4419{ 4420 struct case_node *p, **q, *r; 4421 4422 q = &case_stack->data.case_stmt.case_list; 4423 p = *q; 4424 4425 while ((r = *q)) 4426 { 4427 p = r; 4428 4429 /* Keep going past elements distinctly greater than HIGH. */ 4430 if (tree_int_cst_lt (high, p->low)) 4431 q = &p->left; 4432 4433 /* or distinctly less than LOW. */ 4434 else if (tree_int_cst_lt (p->high, low)) 4435 q = &p->right; 4436 4437 else 4438 { 4439 /* We have an overlap; this is an error. */ 4440 *duplicate = p->code_label; 4441 return 2; 4442 } 4443 } 4444 4445 /* Add this label to the chain, and succeed. 4446 Copy LOW, HIGH so they are on temporary rather than momentary 4447 obstack and will thus survive till the end of the case statement. */ 4448 4449 r = (struct case_node *) oballoc (sizeof (struct case_node)); 4450 r->low = copy_node (low); 4451 4452 /* If the bounds are equal, turn this into the one-value case. */ 4453 4454 if (tree_int_cst_equal (low, high)) 4455 r->high = r->low; 4456 else 4457 { 4458 r->high = copy_node (high); 4459 case_stack->data.case_stmt.num_ranges++; 4460 } 4461 4462 r->code_label = label; 4463 expand_label (label); 4464 4465 *q = r; 4466 r->parent = p; 4467 r->left = 0; 4468 r->right = 0; 4469 r->balance = 0; 4470 4471 while (p) 4472 { 4473 struct case_node *s; 4474 4475 if (r == p->left) 4476 { 4477 int b; 4478 4479 if (! (b = p->balance)) 4480 /* Growth propagation from left side. */ 4481 p->balance = -1; 4482 else if (b < 0) 4483 { 4484 if (r->balance < 0) 4485 { 4486 /* R-Rotation */ 4487 if ((p->left = s = r->right)) 4488 s->parent = p; 4489 4490 r->right = p; 4491 p->balance = 0; 4492 r->balance = 0; 4493 s = p->parent; 4494 p->parent = r; 4495 4496 if ((r->parent = s)) 4497 { 4498 if (s->left == p) 4499 s->left = r; 4500 else 4501 s->right = r; 4502 } 4503 else 4504 case_stack->data.case_stmt.case_list = r; 4505 } 4506 else 4507 /* r->balance == +1 */ 4508 { 4509 /* LR-Rotation */ 4510 4511 int b2; 4512 struct case_node *t = r->right; 4513 4514 if ((p->left = s = t->right)) 4515 s->parent = p; 4516 4517 t->right = p; 4518 if ((r->right = s = t->left)) 4519 s->parent = r; 4520 4521 t->left = r; 4522 b = t->balance; 4523 b2 = b < 0; 4524 p->balance = b2; 4525 b2 = -b2 - b; 4526 r->balance = b2; 4527 t->balance = 0; 4528 s = p->parent; 4529 p->parent = t; 4530 r->parent = t; 4531 4532 if ((t->parent = s)) 4533 { 4534 if (s->left == p) 4535 s->left = t; 4536 else 4537 s->right = t; 4538 } 4539 else 4540 case_stack->data.case_stmt.case_list = t; 4541 } 4542 break; 4543 } 4544 4545 else 4546 { 4547 /* p->balance == +1; growth of left side balances the node. */ 4548 p->balance = 0; 4549 break; 4550 } 4551 } 4552 else 4553 /* r == p->right */ 4554 { 4555 int b; 4556 4557 if (! (b = p->balance)) 4558 /* Growth propagation from right side. */ 4559 p->balance++; 4560 else if (b > 0) 4561 { 4562 if (r->balance > 0) 4563 { 4564 /* L-Rotation */ 4565 4566 if ((p->right = s = r->left)) 4567 s->parent = p; 4568 4569 r->left = p; 4570 p->balance = 0; 4571 r->balance = 0; 4572 s = p->parent; 4573 p->parent = r; 4574 if ((r->parent = s)) 4575 { 4576 if (s->left == p) 4577 s->left = r; 4578 else 4579 s->right = r; 4580 } 4581 4582 else 4583 case_stack->data.case_stmt.case_list = r; 4584 } 4585 4586 else 4587 /* r->balance == -1 */ 4588 { 4589 /* RL-Rotation */ 4590 int b2; 4591 struct case_node *t = r->left; 4592 4593 if ((p->right = s = t->left)) 4594 s->parent = p; 4595 4596 t->left = p; 4597 4598 if ((r->left = s = t->right)) 4599 s->parent = r; 4600 4601 t->right = r; 4602 b = t->balance; 4603 b2 = b < 0; 4604 r->balance = b2; 4605 b2 = -b2 - b; 4606 p->balance = b2; 4607 t->balance = 0; 4608 s = p->parent; 4609 p->parent = t; 4610 r->parent = t; 4611 4612 if ((t->parent = s)) 4613 { 4614 if (s->left == p) 4615 s->left = t; 4616 else 4617 s->right = t; 4618 } 4619 4620 else 4621 case_stack->data.case_stmt.case_list = t; 4622 } 4623 break; 4624 } 4625 else 4626 { 4627 /* p->balance == -1; growth of right side balances the node. */ 4628 p->balance = 0; 4629 break; 4630 } 4631 } 4632 4633 r = p; 4634 p = p->parent; 4635 } 4636 4637 return 0; 4638} 4639 4640 4641/* Returns the number of possible values of TYPE. 4642 Returns -1 if the number is unknown or variable. 4643 Returns -2 if the number does not fit in a HOST_WIDE_INT. 4644 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values 4645 do not increase monotonically (there may be duplicates); 4646 to 1 if the values increase monotonically, but not always by 1; 4647 otherwise sets it to 0. */ 4648 4649HOST_WIDE_INT 4650all_cases_count (type, spareness) 4651 tree type; 4652 int *spareness; 4653{ 4654 HOST_WIDE_INT count; 4655 *spareness = 0; 4656 4657 switch (TREE_CODE (type)) 4658 { 4659 tree t; 4660 case BOOLEAN_TYPE: 4661 count = 2; 4662 break; 4663 case CHAR_TYPE: 4664 count = 1 << BITS_PER_UNIT; 4665 break; 4666 default: 4667 case INTEGER_TYPE: 4668 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST 4669 || TYPE_MAX_VALUE (type) == NULL 4670 || TREE_CODE (TYPE_MAX_VALUE (type)) != INTEGER_CST) 4671 return -1; 4672 else 4673 { 4674 /* count 4675 = TREE_INT_CST_LOW (TYPE_MAX_VALUE (type)) 4676 - TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + 1 4677 but with overflow checking. */ 4678 tree mint = TYPE_MIN_VALUE (type); 4679 tree maxt = TYPE_MAX_VALUE (type); 4680 HOST_WIDE_INT lo, hi; 4681 neg_double(TREE_INT_CST_LOW (mint), TREE_INT_CST_HIGH (mint), 4682 &lo, &hi); 4683 add_double(TREE_INT_CST_LOW (maxt), TREE_INT_CST_HIGH (maxt), 4684 lo, hi, &lo, &hi); 4685 add_double (lo, hi, 1, 0, &lo, &hi); 4686 if (hi != 0 || lo < 0) 4687 return -2; 4688 count = lo; 4689 } 4690 break; 4691 case ENUMERAL_TYPE: 4692 count = 0; 4693 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t)) 4694 { 4695 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST 4696 || TREE_CODE (TREE_VALUE (t)) != INTEGER_CST 4697 || TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + count 4698 != TREE_INT_CST_LOW (TREE_VALUE (t))) 4699 *spareness = 1; 4700 count++; 4701 } 4702 if (*spareness == 1) 4703 { 4704 tree prev = TREE_VALUE (TYPE_VALUES (type)); 4705 for (t = TYPE_VALUES (type); t = TREE_CHAIN (t), t != NULL_TREE; ) 4706 { 4707 if (! tree_int_cst_lt (prev, TREE_VALUE (t))) 4708 { 4709 *spareness = 2; 4710 break; 4711 } 4712 prev = TREE_VALUE (t); 4713 } 4714 4715 } 4716 } 4717 return count; 4718} 4719 4720 4721#define BITARRAY_TEST(ARRAY, INDEX) \ 4722 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\ 4723 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))) 4724#define BITARRAY_SET(ARRAY, INDEX) \ 4725 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\ 4726 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)) 4727 4728/* Set the elements of the bitstring CASES_SEEN (which has length COUNT), 4729 with the case values we have seen, assuming the case expression 4730 has the given TYPE. 4731 SPARSENESS is as determined by all_cases_count. 4732 4733 The time needed is proportional to COUNT, unless 4734 SPARSENESS is 2, in which case quadratic time is needed. */ 4735 4736void 4737mark_seen_cases (type, cases_seen, count, sparseness) 4738 tree type; 4739 unsigned char *cases_seen; 4740 long count; 4741 int sparseness; 4742{ 4743 tree next_node_to_try = NULL_TREE; 4744 long next_node_offset = 0; 4745 4746 register struct case_node *n, *root = case_stack->data.case_stmt.case_list; 4747 tree val = make_node (INTEGER_CST); 4748 TREE_TYPE (val) = type; 4749 if (! root) 4750 ; /* Do nothing */ 4751 else if (sparseness == 2) 4752 { 4753 tree t; 4754 HOST_WIDE_INT xlo; 4755 4756 /* This less efficient loop is only needed to handle 4757 duplicate case values (multiple enum constants 4758 with the same value). */ 4759 TREE_TYPE (val) = TREE_TYPE (root->low); 4760 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE; 4761 t = TREE_CHAIN (t), xlo++) 4762 { 4763 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (TREE_VALUE (t)); 4764 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (TREE_VALUE (t)); 4765 n = root; 4766 do 4767 { 4768 /* Keep going past elements distinctly greater than VAL. */ 4769 if (tree_int_cst_lt (val, n->low)) 4770 n = n->left; 4771 4772 /* or distinctly less than VAL. */ 4773 else if (tree_int_cst_lt (n->high, val)) 4774 n = n->right; 4775 4776 else 4777 { 4778 /* We have found a matching range. */ 4779 BITARRAY_SET (cases_seen, xlo); 4780 break; 4781 } 4782 } 4783 while (n); 4784 } 4785 } 4786 else 4787 { 4788 if (root->left) 4789 case_stack->data.case_stmt.case_list = root = case_tree2list (root, 0); 4790 for (n = root; n; n = n->right) 4791 { 4792 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low); 4793 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low); 4794 while ( ! tree_int_cst_lt (n->high, val)) 4795 { 4796 /* Calculate (into xlo) the "offset" of the integer (val). 4797 The element with lowest value has offset 0, the next smallest 4798 element has offset 1, etc. */ 4799 4800 HOST_WIDE_INT xlo, xhi; 4801 tree t; 4802 if (sparseness && TYPE_VALUES (type) != NULL_TREE) 4803 { 4804 /* The TYPE_VALUES will be in increasing order, so 4805 starting searching where we last ended. */ 4806 t = next_node_to_try; 4807 xlo = next_node_offset; 4808 xhi = 0; 4809 for (;;) 4810 { 4811 if (t == NULL_TREE) 4812 { 4813 t = TYPE_VALUES (type); 4814 xlo = 0; 4815 } 4816 if (tree_int_cst_equal (val, TREE_VALUE (t))) 4817 { 4818 next_node_to_try = TREE_CHAIN (t); 4819 next_node_offset = xlo + 1; 4820 break; 4821 } 4822 xlo++; 4823 t = TREE_CHAIN (t); 4824 if (t == next_node_to_try) 4825 { 4826 xlo = -1; 4827 break; 4828 } 4829 } 4830 } 4831 else 4832 { 4833 t = TYPE_MIN_VALUE (type); 4834 if (t) 4835 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t), 4836 &xlo, &xhi); 4837 else 4838 xlo = xhi = 0; 4839 add_double (xlo, xhi, 4840 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val), 4841 &xlo, &xhi); 4842 } 4843 4844 if (xhi == 0 && xlo >= 0 && xlo < count) 4845 BITARRAY_SET (cases_seen, xlo); 4846 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val), 4847 1, 0, 4848 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val)); 4849 } 4850 } 4851 } 4852} 4853 4854/* Called when the index of a switch statement is an enumerated type 4855 and there is no default label. 4856 4857 Checks that all enumeration literals are covered by the case 4858 expressions of a switch. Also, warn if there are any extra 4859 switch cases that are *not* elements of the enumerated type. 4860 4861 If all enumeration literals were covered by the case expressions, 4862 turn one of the expressions into the default expression since it should 4863 not be possible to fall through such a switch. */ 4864 4865void 4866check_for_full_enumeration_handling (type) 4867 tree type; 4868{ 4869 register struct case_node *n; 4870 register tree chain; 4871#if 0 /* variable used by 'if 0'ed code below. */ 4872 register struct case_node **l; 4873 int all_values = 1; 4874#endif 4875 4876 /* True iff the selector type is a numbered set mode. */ 4877 int sparseness = 0; 4878 4879 /* The number of possible selector values. */ 4880 HOST_WIDE_INT size; 4881 4882 /* For each possible selector value. a one iff it has been matched 4883 by a case value alternative. */ 4884 unsigned char *cases_seen; 4885 4886 /* The allocated size of cases_seen, in chars. */ 4887 long bytes_needed; 4888 4889 if (! warn_switch) 4890 return; 4891 4892 size = all_cases_count (type, &sparseness); 4893 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR; 4894 4895 if (size > 0 && size < 600000 4896 /* We deliberately use malloc here - not xmalloc. */ 4897 && (cases_seen = (unsigned char *) malloc (bytes_needed)) != NULL) 4898 { 4899 long i; 4900 tree v = TYPE_VALUES (type); 4901 bzero (cases_seen, bytes_needed); 4902 4903 /* The time complexity of this code is normally O(N), where 4904 N being the number of members in the enumerated type. 4905 However, if type is a ENUMERAL_TYPE whose values do not 4906 increase monotonically, O(N*log(N)) time may be needed. */ 4907 4908 mark_seen_cases (type, cases_seen, size, sparseness); 4909 4910 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v)) 4911 { 4912 if (BITARRAY_TEST(cases_seen, i) == 0) 4913 warning ("enumeration value `%s' not handled in switch", 4914 IDENTIFIER_POINTER (TREE_PURPOSE (v))); 4915 } 4916 4917 free (cases_seen); 4918 } 4919 4920 /* Now we go the other way around; we warn if there are case 4921 expressions that don't correspond to enumerators. This can 4922 occur since C and C++ don't enforce type-checking of 4923 assignments to enumeration variables. */ 4924 4925 if (case_stack->data.case_stmt.case_list 4926 && case_stack->data.case_stmt.case_list->left) 4927 case_stack->data.case_stmt.case_list 4928 = case_tree2list (case_stack->data.case_stmt.case_list, 0); 4929 if (warn_switch) 4930 for (n = case_stack->data.case_stmt.case_list; n; n = n->right) 4931 { 4932 for (chain = TYPE_VALUES (type); 4933 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain)); 4934 chain = TREE_CHAIN (chain)) 4935 ; 4936 4937 if (!chain) 4938 { 4939 if (TYPE_NAME (type) == 0) 4940 warning ("case value `%ld' not in enumerated type", 4941 (long) TREE_INT_CST_LOW (n->low)); 4942 else 4943 warning ("case value `%ld' not in enumerated type `%s'", 4944 (long) TREE_INT_CST_LOW (n->low), 4945 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type)) 4946 == IDENTIFIER_NODE) 4947 ? TYPE_NAME (type) 4948 : DECL_NAME (TYPE_NAME (type)))); 4949 } 4950 if (!tree_int_cst_equal (n->low, n->high)) 4951 { 4952 for (chain = TYPE_VALUES (type); 4953 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain)); 4954 chain = TREE_CHAIN (chain)) 4955 ; 4956 4957 if (!chain) 4958 { 4959 if (TYPE_NAME (type) == 0) 4960 warning ("case value `%ld' not in enumerated type", 4961 (long) TREE_INT_CST_LOW (n->high)); 4962 else 4963 warning ("case value `%ld' not in enumerated type `%s'", 4964 (long) TREE_INT_CST_LOW (n->high), 4965 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type)) 4966 == IDENTIFIER_NODE) 4967 ? TYPE_NAME (type) 4968 : DECL_NAME (TYPE_NAME (type)))); 4969 } 4970 } 4971 } 4972 4973#if 0 4974 /* ??? This optimization is disabled because it causes valid programs to 4975 fail. ANSI C does not guarantee that an expression with enum type 4976 will have a value that is the same as one of the enumeration literals. */ 4977 4978 /* If all values were found as case labels, make one of them the default 4979 label. Thus, this switch will never fall through. We arbitrarily pick 4980 the last one to make the default since this is likely the most 4981 efficient choice. */ 4982 4983 if (all_values) 4984 { 4985 for (l = &case_stack->data.case_stmt.case_list; 4986 (*l)->right != 0; 4987 l = &(*l)->right) 4988 ; 4989 4990 case_stack->data.case_stmt.default_label = (*l)->code_label; 4991 *l = 0; 4992 } 4993#endif /* 0 */ 4994} 4995 4996 4997/* Terminate a case (Pascal) or switch (C) statement 4998 in which ORIG_INDEX is the expression to be tested. 4999 Generate the code to test it and jump to the right place. */ 5000 5001void 5002expand_end_case (orig_index) 5003 tree orig_index; 5004{ 5005 tree minval = NULL_TREE, maxval = NULL_TREE, range, orig_minval; 5006 rtx default_label = 0; 5007 register struct case_node *n; 5008 unsigned int count; 5009 rtx index; 5010 rtx table_label; 5011 int ncases; 5012 rtx *labelvec; 5013 register int i; 5014 rtx before_case; 5015 register struct nesting *thiscase = case_stack; 5016 tree index_expr, index_type; 5017 int unsignedp; 5018 5019 table_label = gen_label_rtx (); 5020 index_expr = thiscase->data.case_stmt.index_expr; 5021 index_type = TREE_TYPE (index_expr); 5022 unsignedp = TREE_UNSIGNED (index_type); 5023 5024 do_pending_stack_adjust (); 5025 5026 /* This might get an spurious warning in the presence of a syntax error; 5027 it could be fixed by moving the call to check_seenlabel after the 5028 check for error_mark_node, and copying the code of check_seenlabel that 5029 deals with case_stack->data.case_stmt.line_number_status / 5030 restore_line_number_status in front of the call to end_cleanup_deferral; 5031 However, this might miss some useful warnings in the presence of 5032 non-syntax errors. */ 5033 check_seenlabel (); 5034 5035 /* An ERROR_MARK occurs for various reasons including invalid data type. */ 5036 if (index_type != error_mark_node) 5037 { 5038 /* If switch expression was an enumerated type, check that all 5039 enumeration literals are covered by the cases. 5040 No sense trying this if there's a default case, however. */ 5041 5042 if (!thiscase->data.case_stmt.default_label 5043 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE 5044 && TREE_CODE (index_expr) != INTEGER_CST) 5045 check_for_full_enumeration_handling (TREE_TYPE (orig_index)); 5046 5047 /* If we don't have a default-label, create one here, 5048 after the body of the switch. */ 5049 if (thiscase->data.case_stmt.default_label == 0) 5050 { 5051 thiscase->data.case_stmt.default_label 5052 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE); 5053 expand_label (thiscase->data.case_stmt.default_label); 5054 } 5055 default_label = label_rtx (thiscase->data.case_stmt.default_label); 5056 5057 before_case = get_last_insn (); 5058 5059 if (thiscase->data.case_stmt.case_list 5060 && thiscase->data.case_stmt.case_list->left) 5061 thiscase->data.case_stmt.case_list 5062 = case_tree2list(thiscase->data.case_stmt.case_list, 0); 5063 5064 /* Simplify the case-list before we count it. */ 5065 group_case_nodes (thiscase->data.case_stmt.case_list); 5066 5067 /* Get upper and lower bounds of case values. 5068 Also convert all the case values to the index expr's data type. */ 5069 5070 count = 0; 5071 for (n = thiscase->data.case_stmt.case_list; n; n = n->right) 5072 { 5073 /* Check low and high label values are integers. */ 5074 if (TREE_CODE (n->low) != INTEGER_CST) 5075 abort (); 5076 if (TREE_CODE (n->high) != INTEGER_CST) 5077 abort (); 5078 5079 n->low = convert (index_type, n->low); 5080 n->high = convert (index_type, n->high); 5081 5082 /* Count the elements and track the largest and smallest 5083 of them (treating them as signed even if they are not). */ 5084 if (count++ == 0) 5085 { 5086 minval = n->low; 5087 maxval = n->high; 5088 } 5089 else 5090 { 5091 if (INT_CST_LT (n->low, minval)) 5092 minval = n->low; 5093 if (INT_CST_LT (maxval, n->high)) 5094 maxval = n->high; 5095 } 5096 /* A range counts double, since it requires two compares. */ 5097 if (! tree_int_cst_equal (n->low, n->high)) 5098 count++; 5099 } 5100 5101 orig_minval = minval; 5102 5103 /* Compute span of values. */ 5104 if (count != 0) 5105 range = fold (build (MINUS_EXPR, index_type, maxval, minval)); 5106 5107 end_cleanup_deferral (); 5108 5109 if (count == 0) 5110 { 5111 expand_expr (index_expr, const0_rtx, VOIDmode, 0); 5112 emit_queue (); 5113 emit_jump (default_label); 5114 } 5115 5116 /* If range of values is much bigger than number of values, 5117 make a sequence of conditional branches instead of a dispatch. 5118 If the switch-index is a constant, do it this way 5119 because we can optimize it. */ 5120 5121#ifndef CASE_VALUES_THRESHOLD 5122#ifdef HAVE_casesi 5123#define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5) 5124#else 5125 /* If machine does not have a case insn that compares the 5126 bounds, this means extra overhead for dispatch tables 5127 which raises the threshold for using them. */ 5128#define CASE_VALUES_THRESHOLD 5 5129#endif /* HAVE_casesi */ 5130#endif /* CASE_VALUES_THRESHOLD */ 5131 5132 else if (TREE_INT_CST_HIGH (range) != 0 5133 || count < (unsigned int) CASE_VALUES_THRESHOLD 5134 || ((unsigned HOST_WIDE_INT) (TREE_INT_CST_LOW (range)) 5135 > 10 * count) 5136#ifndef ASM_OUTPUT_ADDR_DIFF_ELT 5137 || flag_pic 5138#endif 5139 || TREE_CODE (index_expr) == INTEGER_CST 5140 /* These will reduce to a constant. */ 5141 || (TREE_CODE (index_expr) == CALL_EXPR 5142 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR 5143 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL 5144 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE) 5145 || (TREE_CODE (index_expr) == COMPOUND_EXPR 5146 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST)) 5147 { 5148 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0); 5149 5150 /* If the index is a short or char that we do not have 5151 an insn to handle comparisons directly, convert it to 5152 a full integer now, rather than letting each comparison 5153 generate the conversion. */ 5154 5155 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT 5156 && (cmp_optab->handlers[(int) GET_MODE(index)].insn_code 5157 == CODE_FOR_nothing)) 5158 { 5159 enum machine_mode wider_mode; 5160 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode; 5161 wider_mode = GET_MODE_WIDER_MODE (wider_mode)) 5162 if (cmp_optab->handlers[(int) wider_mode].insn_code 5163 != CODE_FOR_nothing) 5164 { 5165 index = convert_to_mode (wider_mode, index, unsignedp); 5166 break; 5167 } 5168 } 5169 5170 emit_queue (); 5171 do_pending_stack_adjust (); 5172 5173 index = protect_from_queue (index, 0); 5174 if (GET_CODE (index) == MEM) 5175 index = copy_to_reg (index); 5176 if (GET_CODE (index) == CONST_INT 5177 || TREE_CODE (index_expr) == INTEGER_CST) 5178 { 5179 /* Make a tree node with the proper constant value 5180 if we don't already have one. */ 5181 if (TREE_CODE (index_expr) != INTEGER_CST) 5182 { 5183 index_expr 5184 = build_int_2 (INTVAL (index), 5185 unsignedp || INTVAL (index) >= 0 ? 0 : -1); 5186 index_expr = convert (index_type, index_expr); 5187 } 5188 5189 /* For constant index expressions we need only 5190 issue a unconditional branch to the appropriate 5191 target code. The job of removing any unreachable 5192 code is left to the optimisation phase if the 5193 "-O" option is specified. */ 5194 for (n = thiscase->data.case_stmt.case_list; n; n = n->right) 5195 if (! tree_int_cst_lt (index_expr, n->low) 5196 && ! tree_int_cst_lt (n->high, index_expr)) 5197 break; 5198 5199 if (n) 5200 emit_jump (label_rtx (n->code_label)); 5201 else 5202 emit_jump (default_label); 5203 } 5204 else 5205 { 5206 /* If the index expression is not constant we generate 5207 a binary decision tree to select the appropriate 5208 target code. This is done as follows: 5209 5210 The list of cases is rearranged into a binary tree, 5211 nearly optimal assuming equal probability for each case. 5212 5213 The tree is transformed into RTL, eliminating 5214 redundant test conditions at the same time. 5215 5216 If program flow could reach the end of the 5217 decision tree an unconditional jump to the 5218 default code is emitted. */ 5219 5220 use_cost_table 5221 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE 5222 && estimate_case_costs (thiscase->data.case_stmt.case_list)); 5223 balance_case_nodes (&thiscase->data.case_stmt.case_list, 5224 NULL_PTR); 5225 emit_case_nodes (index, thiscase->data.case_stmt.case_list, 5226 default_label, index_type); 5227 emit_jump_if_reachable (default_label); 5228 } 5229 } 5230 else 5231 { 5232 int win = 0; 5233#ifdef HAVE_casesi 5234 if (HAVE_casesi) 5235 { 5236 enum machine_mode index_mode = SImode; 5237 int index_bits = GET_MODE_BITSIZE (index_mode); 5238 rtx op1, op2; 5239 enum machine_mode op_mode; 5240 5241 /* Convert the index to SImode. */ 5242 if (GET_MODE_BITSIZE (TYPE_MODE (index_type)) 5243 > GET_MODE_BITSIZE (index_mode)) 5244 { 5245 enum machine_mode omode = TYPE_MODE (index_type); 5246 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0); 5247 5248 /* We must handle the endpoints in the original mode. */ 5249 index_expr = build (MINUS_EXPR, index_type, 5250 index_expr, minval); 5251 minval = integer_zero_node; 5252 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0); 5253 emit_cmp_and_jump_insns (rangertx, index, LTU, NULL_RTX, 5254 omode, 1, 0, default_label); 5255 /* Now we can safely truncate. */ 5256 index = convert_to_mode (index_mode, index, 0); 5257 } 5258 else 5259 { 5260 if (TYPE_MODE (index_type) != index_mode) 5261 { 5262 index_expr = convert (type_for_size (index_bits, 0), 5263 index_expr); 5264 index_type = TREE_TYPE (index_expr); 5265 } 5266 5267 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0); 5268 } 5269 emit_queue (); 5270 index = protect_from_queue (index, 0); 5271 do_pending_stack_adjust (); 5272 5273 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][0]; 5274 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][0]) 5275 (index, op_mode)) 5276 index = copy_to_mode_reg (op_mode, index); 5277 5278 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0); 5279 5280 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][1]; 5281 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][1]) 5282 (op1, op_mode)) 5283 op1 = copy_to_mode_reg (op_mode, op1); 5284 5285 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0); 5286 5287 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][2]; 5288 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][2]) 5289 (op2, op_mode)) 5290 op2 = copy_to_mode_reg (op_mode, op2); 5291 5292 emit_jump_insn (gen_casesi (index, op1, op2, 5293 table_label, default_label)); 5294 win = 1; 5295 } 5296#endif 5297#ifdef HAVE_tablejump 5298 if (! win && HAVE_tablejump) 5299 { 5300 index_expr = convert (thiscase->data.case_stmt.nominal_type, 5301 fold (build (MINUS_EXPR, index_type, 5302 index_expr, minval))); 5303 index_type = TREE_TYPE (index_expr); 5304 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0); 5305 emit_queue (); 5306 index = protect_from_queue (index, 0); 5307 do_pending_stack_adjust (); 5308 5309 do_tablejump (index, TYPE_MODE (index_type), 5310 expand_expr (range, NULL_RTX, VOIDmode, 0), 5311 table_label, default_label); 5312 win = 1; 5313 } 5314#endif 5315 if (! win) 5316 abort (); 5317 5318 /* Get table of labels to jump to, in order of case index. */ 5319 5320 ncases = TREE_INT_CST_LOW (range) + 1; 5321 labelvec = (rtx *) alloca (ncases * sizeof (rtx)); 5322 bzero ((char *) labelvec, ncases * sizeof (rtx)); 5323 5324 for (n = thiscase->data.case_stmt.case_list; n; n = n->right) 5325 { 5326 register HOST_WIDE_INT i 5327 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval); 5328 5329 while (1) 5330 { 5331 labelvec[i] 5332 = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label)); 5333 if (i + TREE_INT_CST_LOW (orig_minval) 5334 == TREE_INT_CST_LOW (n->high)) 5335 break; 5336 i++; 5337 } 5338 } 5339 5340 /* Fill in the gaps with the default. */ 5341 for (i = 0; i < ncases; i++) 5342 if (labelvec[i] == 0) 5343 labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label); 5344 5345 /* Output the table */ 5346 emit_label (table_label); 5347 5348 if (CASE_VECTOR_PC_RELATIVE || flag_pic) 5349 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE, 5350 gen_rtx_LABEL_REF (Pmode, table_label), 5351 gen_rtvec_v (ncases, labelvec), 5352 const0_rtx, const0_rtx, 0)); 5353 else 5354 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE, 5355 gen_rtvec_v (ncases, labelvec))); 5356 5357 /* If the case insn drops through the table, 5358 after the table we must jump to the default-label. 5359 Otherwise record no drop-through after the table. */ 5360#ifdef CASE_DROPS_THROUGH 5361 emit_jump (default_label); 5362#else 5363 emit_barrier (); 5364#endif 5365 } 5366 5367 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ()); 5368 reorder_insns (before_case, get_last_insn (), 5369 thiscase->data.case_stmt.start); 5370 } 5371 else 5372 end_cleanup_deferral (); 5373 5374 if (thiscase->exit_label) 5375 emit_label (thiscase->exit_label); 5376 5377 POPSTACK (case_stack); 5378 5379 free_temp_slots (); 5380} 5381 5382/* Convert the tree NODE into a list linked by the right field, with the left 5383 field zeroed. RIGHT is used for recursion; it is a list to be placed 5384 rightmost in the resulting list. */ 5385 5386static struct case_node * 5387case_tree2list (node, right) 5388 struct case_node *node, *right; 5389{ 5390 struct case_node *left; 5391 5392 if (node->right) 5393 right = case_tree2list (node->right, right); 5394 5395 node->right = right; 5396 if ((left = node->left)) 5397 { 5398 node->left = 0; 5399 return case_tree2list (left, node); 5400 } 5401 5402 return node; 5403} 5404 5405/* Generate code to jump to LABEL if OP1 and OP2 are equal. */ 5406 5407static void 5408do_jump_if_equal (op1, op2, label, unsignedp) 5409 rtx op1, op2, label; 5410 int unsignedp; 5411{ 5412 if (GET_CODE (op1) == CONST_INT 5413 && GET_CODE (op2) == CONST_INT) 5414 { 5415 if (INTVAL (op1) == INTVAL (op2)) 5416 emit_jump (label); 5417 } 5418 else 5419 { 5420 enum machine_mode mode = GET_MODE (op1); 5421 if (mode == VOIDmode) 5422 mode = GET_MODE (op2); 5423 emit_cmp_and_jump_insns (op1, op2, EQ, NULL_RTX, mode, unsignedp, 5424 0, label); 5425 } 5426} 5427 5428/* Not all case values are encountered equally. This function 5429 uses a heuristic to weight case labels, in cases where that 5430 looks like a reasonable thing to do. 5431 5432 Right now, all we try to guess is text, and we establish the 5433 following weights: 5434 5435 chars above space: 16 5436 digits: 16 5437 default: 12 5438 space, punct: 8 5439 tab: 4 5440 newline: 2 5441 other "\" chars: 1 5442 remaining chars: 0 5443 5444 If we find any cases in the switch that are not either -1 or in the range 5445 of valid ASCII characters, or are control characters other than those 5446 commonly used with "\", don't treat this switch scanning text. 5447 5448 Return 1 if these nodes are suitable for cost estimation, otherwise 5449 return 0. */ 5450 5451static int 5452estimate_case_costs (node) 5453 case_node_ptr node; 5454{ 5455 tree min_ascii = build_int_2 (-1, -1); 5456 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0)); 5457 case_node_ptr n; 5458 int i; 5459 5460 /* If we haven't already made the cost table, make it now. Note that the 5461 lower bound of the table is -1, not zero. */ 5462 5463 if (cost_table == NULL) 5464 { 5465 cost_table = ((short *) xmalloc (129 * sizeof (short))) + 1; 5466 bzero ((char *) (cost_table - 1), 129 * sizeof (short)); 5467 5468 for (i = 0; i < 128; i++) 5469 { 5470 if (ISALNUM (i)) 5471 cost_table[i] = 16; 5472 else if (ISPUNCT (i)) 5473 cost_table[i] = 8; 5474 else if (ISCNTRL (i)) 5475 cost_table[i] = -1; 5476 } 5477 5478 cost_table[' '] = 8; 5479 cost_table['\t'] = 4; 5480 cost_table['\0'] = 4; 5481 cost_table['\n'] = 2; 5482 cost_table['\f'] = 1; 5483 cost_table['\v'] = 1; 5484 cost_table['\b'] = 1; 5485 } 5486 5487 /* See if all the case expressions look like text. It is text if the 5488 constant is >= -1 and the highest constant is <= 127. Do all comparisons 5489 as signed arithmetic since we don't want to ever access cost_table with a 5490 value less than -1. Also check that none of the constants in a range 5491 are strange control characters. */ 5492 5493 for (n = node; n; n = n->right) 5494 { 5495 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high)) 5496 return 0; 5497 5498 for (i = TREE_INT_CST_LOW (n->low); i <= TREE_INT_CST_LOW (n->high); i++) 5499 if (cost_table[i] < 0) 5500 return 0; 5501 } 5502 5503 /* All interesting values are within the range of interesting 5504 ASCII characters. */ 5505 return 1; 5506} 5507 5508/* Scan an ordered list of case nodes 5509 combining those with consecutive values or ranges. 5510 5511 Eg. three separate entries 1: 2: 3: become one entry 1..3: */ 5512 5513static void 5514group_case_nodes (head) 5515 case_node_ptr head; 5516{ 5517 case_node_ptr node = head; 5518 5519 while (node) 5520 { 5521 rtx lb = next_real_insn (label_rtx (node->code_label)); 5522 rtx lb2; 5523 case_node_ptr np = node; 5524 5525 /* Try to group the successors of NODE with NODE. */ 5526 while (((np = np->right) != 0) 5527 /* Do they jump to the same place? */ 5528 && ((lb2 = next_real_insn (label_rtx (np->code_label))) == lb 5529 || (lb != 0 && lb2 != 0 5530 && simplejump_p (lb) 5531 && simplejump_p (lb2) 5532 && rtx_equal_p (SET_SRC (PATTERN (lb)), 5533 SET_SRC (PATTERN (lb2))))) 5534 /* Are their ranges consecutive? */ 5535 && tree_int_cst_equal (np->low, 5536 fold (build (PLUS_EXPR, 5537 TREE_TYPE (node->high), 5538 node->high, 5539 integer_one_node))) 5540 /* An overflow is not consecutive. */ 5541 && tree_int_cst_lt (node->high, 5542 fold (build (PLUS_EXPR, 5543 TREE_TYPE (node->high), 5544 node->high, 5545 integer_one_node)))) 5546 { 5547 node->high = np->high; 5548 } 5549 /* NP is the first node after NODE which can't be grouped with it. 5550 Delete the nodes in between, and move on to that node. */ 5551 node->right = np; 5552 node = np; 5553 } 5554} 5555 5556/* Take an ordered list of case nodes 5557 and transform them into a near optimal binary tree, 5558 on the assumption that any target code selection value is as 5559 likely as any other. 5560 5561 The transformation is performed by splitting the ordered 5562 list into two equal sections plus a pivot. The parts are 5563 then attached to the pivot as left and right branches. Each 5564 branch is then transformed recursively. */ 5565 5566static void 5567balance_case_nodes (head, parent) 5568 case_node_ptr *head; 5569 case_node_ptr parent; 5570{ 5571 register case_node_ptr np; 5572 5573 np = *head; 5574 if (np) 5575 { 5576 int cost = 0; 5577 int i = 0; 5578 int ranges = 0; 5579 register case_node_ptr *npp; 5580 case_node_ptr left; 5581 5582 /* Count the number of entries on branch. Also count the ranges. */ 5583 5584 while (np) 5585 { 5586 if (!tree_int_cst_equal (np->low, np->high)) 5587 { 5588 ranges++; 5589 if (use_cost_table) 5590 cost += cost_table[TREE_INT_CST_LOW (np->high)]; 5591 } 5592 5593 if (use_cost_table) 5594 cost += cost_table[TREE_INT_CST_LOW (np->low)]; 5595 5596 i++; 5597 np = np->right; 5598 } 5599 5600 if (i > 2) 5601 { 5602 /* Split this list if it is long enough for that to help. */ 5603 npp = head; 5604 left = *npp; 5605 if (use_cost_table) 5606 { 5607 /* Find the place in the list that bisects the list's total cost, 5608 Here I gets half the total cost. */ 5609 int n_moved = 0; 5610 i = (cost + 1) / 2; 5611 while (1) 5612 { 5613 /* Skip nodes while their cost does not reach that amount. */ 5614 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high)) 5615 i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)]; 5616 i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)]; 5617 if (i <= 0) 5618 break; 5619 npp = &(*npp)->right; 5620 n_moved += 1; 5621 } 5622 if (n_moved == 0) 5623 { 5624 /* Leave this branch lopsided, but optimize left-hand 5625 side and fill in `parent' fields for right-hand side. */ 5626 np = *head; 5627 np->parent = parent; 5628 balance_case_nodes (&np->left, np); 5629 for (; np->right; np = np->right) 5630 np->right->parent = np; 5631 return; 5632 } 5633 } 5634 /* If there are just three nodes, split at the middle one. */ 5635 else if (i == 3) 5636 npp = &(*npp)->right; 5637 else 5638 { 5639 /* Find the place in the list that bisects the list's total cost, 5640 where ranges count as 2. 5641 Here I gets half the total cost. */ 5642 i = (i + ranges + 1) / 2; 5643 while (1) 5644 { 5645 /* Skip nodes while their cost does not reach that amount. */ 5646 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high)) 5647 i--; 5648 i--; 5649 if (i <= 0) 5650 break; 5651 npp = &(*npp)->right; 5652 } 5653 } 5654 *head = np = *npp; 5655 *npp = 0; 5656 np->parent = parent; 5657 np->left = left; 5658 5659 /* Optimize each of the two split parts. */ 5660 balance_case_nodes (&np->left, np); 5661 balance_case_nodes (&np->right, np); 5662 } 5663 else 5664 { 5665 /* Else leave this branch as one level, 5666 but fill in `parent' fields. */ 5667 np = *head; 5668 np->parent = parent; 5669 for (; np->right; np = np->right) 5670 np->right->parent = np; 5671 } 5672 } 5673} 5674 5675/* Search the parent sections of the case node tree 5676 to see if a test for the lower bound of NODE would be redundant. 5677 INDEX_TYPE is the type of the index expression. 5678 5679 The instructions to generate the case decision tree are 5680 output in the same order as nodes are processed so it is 5681 known that if a parent node checks the range of the current 5682 node minus one that the current node is bounded at its lower 5683 span. Thus the test would be redundant. */ 5684 5685static int 5686node_has_low_bound (node, index_type) 5687 case_node_ptr node; 5688 tree index_type; 5689{ 5690 tree low_minus_one; 5691 case_node_ptr pnode; 5692 5693 /* If the lower bound of this node is the lowest value in the index type, 5694 we need not test it. */ 5695 5696 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type))) 5697 return 1; 5698 5699 /* If this node has a left branch, the value at the left must be less 5700 than that at this node, so it cannot be bounded at the bottom and 5701 we need not bother testing any further. */ 5702 5703 if (node->left) 5704 return 0; 5705 5706 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low), 5707 node->low, integer_one_node)); 5708 5709 /* If the subtraction above overflowed, we can't verify anything. 5710 Otherwise, look for a parent that tests our value - 1. */ 5711 5712 if (! tree_int_cst_lt (low_minus_one, node->low)) 5713 return 0; 5714 5715 for (pnode = node->parent; pnode; pnode = pnode->parent) 5716 if (tree_int_cst_equal (low_minus_one, pnode->high)) 5717 return 1; 5718 5719 return 0; 5720} 5721 5722/* Search the parent sections of the case node tree 5723 to see if a test for the upper bound of NODE would be redundant. 5724 INDEX_TYPE is the type of the index expression. 5725 5726 The instructions to generate the case decision tree are 5727 output in the same order as nodes are processed so it is 5728 known that if a parent node checks the range of the current 5729 node plus one that the current node is bounded at its upper 5730 span. Thus the test would be redundant. */ 5731 5732static int 5733node_has_high_bound (node, index_type) 5734 case_node_ptr node; 5735 tree index_type; 5736{ 5737 tree high_plus_one; 5738 case_node_ptr pnode; 5739 5740 /* If there is no upper bound, obviously no test is needed. */ 5741 5742 if (TYPE_MAX_VALUE (index_type) == NULL) 5743 return 1; 5744 5745 /* If the upper bound of this node is the highest value in the type 5746 of the index expression, we need not test against it. */ 5747 5748 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type))) 5749 return 1; 5750 5751 /* If this node has a right branch, the value at the right must be greater 5752 than that at this node, so it cannot be bounded at the top and 5753 we need not bother testing any further. */ 5754 5755 if (node->right) 5756 return 0; 5757 5758 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high), 5759 node->high, integer_one_node)); 5760 5761 /* If the addition above overflowed, we can't verify anything. 5762 Otherwise, look for a parent that tests our value + 1. */ 5763 5764 if (! tree_int_cst_lt (node->high, high_plus_one)) 5765 return 0; 5766 5767 for (pnode = node->parent; pnode; pnode = pnode->parent) 5768 if (tree_int_cst_equal (high_plus_one, pnode->low)) 5769 return 1; 5770 5771 return 0; 5772} 5773 5774/* Search the parent sections of the 5775 case node tree to see if both tests for the upper and lower 5776 bounds of NODE would be redundant. */ 5777 5778static int 5779node_is_bounded (node, index_type) 5780 case_node_ptr node; 5781 tree index_type; 5782{ 5783 return (node_has_low_bound (node, index_type) 5784 && node_has_high_bound (node, index_type)); 5785} 5786 5787/* Emit an unconditional jump to LABEL unless it would be dead code. */ 5788 5789static void 5790emit_jump_if_reachable (label) 5791 rtx label; 5792{ 5793 if (GET_CODE (get_last_insn ()) != BARRIER) 5794 emit_jump (label); 5795} 5796 5797/* Emit step-by-step code to select a case for the value of INDEX. 5798 The thus generated decision tree follows the form of the 5799 case-node binary tree NODE, whose nodes represent test conditions. 5800 INDEX_TYPE is the type of the index of the switch. 5801 5802 Care is taken to prune redundant tests from the decision tree 5803 by detecting any boundary conditions already checked by 5804 emitted rtx. (See node_has_high_bound, node_has_low_bound 5805 and node_is_bounded, above.) 5806 5807 Where the test conditions can be shown to be redundant we emit 5808 an unconditional jump to the target code. As a further 5809 optimization, the subordinates of a tree node are examined to 5810 check for bounded nodes. In this case conditional and/or 5811 unconditional jumps as a result of the boundary check for the 5812 current node are arranged to target the subordinates associated 5813 code for out of bound conditions on the current node. 5814 5815 We can assume that when control reaches the code generated here, 5816 the index value has already been compared with the parents 5817 of this node, and determined to be on the same side of each parent 5818 as this node is. Thus, if this node tests for the value 51, 5819 and a parent tested for 52, we don't need to consider 5820 the possibility of a value greater than 51. If another parent 5821 tests for the value 50, then this node need not test anything. */ 5822 5823static void 5824emit_case_nodes (index, node, default_label, index_type) 5825 rtx index; 5826 case_node_ptr node; 5827 rtx default_label; 5828 tree index_type; 5829{ 5830 /* If INDEX has an unsigned type, we must make unsigned branches. */ 5831 int unsignedp = TREE_UNSIGNED (index_type); 5832 typedef rtx rtx_fn (); 5833 enum machine_mode mode = GET_MODE (index); 5834 5835 /* See if our parents have already tested everything for us. 5836 If they have, emit an unconditional jump for this node. */ 5837 if (node_is_bounded (node, index_type)) 5838 emit_jump (label_rtx (node->code_label)); 5839 5840 else if (tree_int_cst_equal (node->low, node->high)) 5841 { 5842 /* Node is single valued. First see if the index expression matches 5843 this node and then check our children, if any. */ 5844 5845 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0), 5846 label_rtx (node->code_label), unsignedp); 5847 5848 if (node->right != 0 && node->left != 0) 5849 { 5850 /* This node has children on both sides. 5851 Dispatch to one side or the other 5852 by comparing the index value with this node's value. 5853 If one subtree is bounded, check that one first, 5854 so we can avoid real branches in the tree. */ 5855 5856 if (node_is_bounded (node->right, index_type)) 5857 { 5858 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX, 5859 VOIDmode, 0), 5860 GT, NULL_RTX, mode, unsignedp, 0, 5861 label_rtx (node->right->code_label)); 5862 emit_case_nodes (index, node->left, default_label, index_type); 5863 } 5864 5865 else if (node_is_bounded (node->left, index_type)) 5866 { 5867 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX, 5868 VOIDmode, 0), 5869 LT, NULL_RTX, mode, unsignedp, 0, 5870 label_rtx (node->left->code_label)); 5871 emit_case_nodes (index, node->right, default_label, index_type); 5872 } 5873 5874 else 5875 { 5876 /* Neither node is bounded. First distinguish the two sides; 5877 then emit the code for one side at a time. */ 5878 5879 tree test_label 5880 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE); 5881 5882 /* See if the value is on the right. */ 5883 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX, 5884 VOIDmode, 0), 5885 GT, NULL_RTX, mode, unsignedp, 0, 5886 label_rtx (test_label)); 5887 5888 /* Value must be on the left. 5889 Handle the left-hand subtree. */ 5890 emit_case_nodes (index, node->left, default_label, index_type); 5891 /* If left-hand subtree does nothing, 5892 go to default. */ 5893 emit_jump_if_reachable (default_label); 5894 5895 /* Code branches here for the right-hand subtree. */ 5896 expand_label (test_label); 5897 emit_case_nodes (index, node->right, default_label, index_type); 5898 } 5899 } 5900 5901 else if (node->right != 0 && node->left == 0) 5902 { 5903 /* Here we have a right child but no left so we issue conditional 5904 branch to default and process the right child. 5905 5906 Omit the conditional branch to default if we it avoid only one 5907 right child; it costs too much space to save so little time. */ 5908 5909 if (node->right->right || node->right->left 5910 || !tree_int_cst_equal (node->right->low, node->right->high)) 5911 { 5912 if (!node_has_low_bound (node, index_type)) 5913 { 5914 emit_cmp_and_jump_insns (index, expand_expr (node->high, 5915 NULL_RTX, 5916 VOIDmode, 0), 5917 LT, NULL_RTX, mode, unsignedp, 0, 5918 default_label); 5919 } 5920 5921 emit_case_nodes (index, node->right, default_label, index_type); 5922 } 5923 else 5924 /* We cannot process node->right normally 5925 since we haven't ruled out the numbers less than 5926 this node's value. So handle node->right explicitly. */ 5927 do_jump_if_equal (index, 5928 expand_expr (node->right->low, NULL_RTX, 5929 VOIDmode, 0), 5930 label_rtx (node->right->code_label), unsignedp); 5931 } 5932 5933 else if (node->right == 0 && node->left != 0) 5934 { 5935 /* Just one subtree, on the left. */ 5936 5937#if 0 /* The following code and comment were formerly part 5938 of the condition here, but they didn't work 5939 and I don't understand what the idea was. -- rms. */ 5940 /* If our "most probable entry" is less probable 5941 than the default label, emit a jump to 5942 the default label using condition codes 5943 already lying around. With no right branch, 5944 a branch-greater-than will get us to the default 5945 label correctly. */ 5946 if (use_cost_table 5947 && cost_table[TREE_INT_CST_LOW (node->high)] < 12) 5948 ; 5949#endif /* 0 */ 5950 if (node->left->left || node->left->right 5951 || !tree_int_cst_equal (node->left->low, node->left->high)) 5952 { 5953 if (!node_has_high_bound (node, index_type)) 5954 { 5955 emit_cmp_and_jump_insns (index, expand_expr (node->high, 5956 NULL_RTX, 5957 VOIDmode, 0), 5958 GT, NULL_RTX, mode, unsignedp, 0, 5959 default_label); 5960 } 5961 5962 emit_case_nodes (index, node->left, default_label, index_type); 5963 } 5964 else 5965 /* We cannot process node->left normally 5966 since we haven't ruled out the numbers less than 5967 this node's value. So handle node->left explicitly. */ 5968 do_jump_if_equal (index, 5969 expand_expr (node->left->low, NULL_RTX, 5970 VOIDmode, 0), 5971 label_rtx (node->left->code_label), unsignedp); 5972 } 5973 } 5974 else 5975 { 5976 /* Node is a range. These cases are very similar to those for a single 5977 value, except that we do not start by testing whether this node 5978 is the one to branch to. */ 5979 5980 if (node->right != 0 && node->left != 0) 5981 { 5982 /* Node has subtrees on both sides. 5983 If the right-hand subtree is bounded, 5984 test for it first, since we can go straight there. 5985 Otherwise, we need to make a branch in the control structure, 5986 then handle the two subtrees. */ 5987 tree test_label = 0; 5988 5989 5990 if (node_is_bounded (node->right, index_type)) 5991 /* Right hand node is fully bounded so we can eliminate any 5992 testing and branch directly to the target code. */ 5993 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX, 5994 VOIDmode, 0), 5995 GT, NULL_RTX, mode, unsignedp, 0, 5996 label_rtx (node->right->code_label)); 5997 else 5998 { 5999 /* Right hand node requires testing. 6000 Branch to a label where we will handle it later. */ 6001 6002 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE); 6003 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX, 6004 VOIDmode, 0), 6005 GT, NULL_RTX, mode, unsignedp, 0, 6006 label_rtx (test_label)); 6007 } 6008 6009 /* Value belongs to this node or to the left-hand subtree. */ 6010 6011 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX, 6012 VOIDmode, 0), 6013 GE, NULL_RTX, mode, unsignedp, 0, 6014 label_rtx (node->code_label)); 6015 6016 /* Handle the left-hand subtree. */ 6017 emit_case_nodes (index, node->left, default_label, index_type); 6018 6019 /* If right node had to be handled later, do that now. */ 6020 6021 if (test_label) 6022 { 6023 /* If the left-hand subtree fell through, 6024 don't let it fall into the right-hand subtree. */ 6025 emit_jump_if_reachable (default_label); 6026 6027 expand_label (test_label); 6028 emit_case_nodes (index, node->right, default_label, index_type); 6029 } 6030 } 6031 6032 else if (node->right != 0 && node->left == 0) 6033 { 6034 /* Deal with values to the left of this node, 6035 if they are possible. */ 6036 if (!node_has_low_bound (node, index_type)) 6037 { 6038 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX, 6039 VOIDmode, 0), 6040 LT, NULL_RTX, mode, unsignedp, 0, 6041 default_label); 6042 } 6043 6044 /* Value belongs to this node or to the right-hand subtree. */ 6045 6046 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX, 6047 VOIDmode, 0), 6048 LE, NULL_RTX, mode, unsignedp, 0, 6049 label_rtx (node->code_label)); 6050 6051 emit_case_nodes (index, node->right, default_label, index_type); 6052 } 6053 6054 else if (node->right == 0 && node->left != 0) 6055 { 6056 /* Deal with values to the right of this node, 6057 if they are possible. */ 6058 if (!node_has_high_bound (node, index_type)) 6059 { 6060 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX, 6061 VOIDmode, 0), 6062 GT, NULL_RTX, mode, unsignedp, 0, 6063 default_label); 6064 } 6065 6066 /* Value belongs to this node or to the left-hand subtree. */ 6067 6068 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX, 6069 VOIDmode, 0), 6070 GE, NULL_RTX, mode, unsignedp, 0, 6071 label_rtx (node->code_label)); 6072 6073 emit_case_nodes (index, node->left, default_label, index_type); 6074 } 6075 6076 else 6077 { 6078 /* Node has no children so we check low and high bounds to remove 6079 redundant tests. Only one of the bounds can exist, 6080 since otherwise this node is bounded--a case tested already. */ 6081 6082 if (!node_has_high_bound (node, index_type)) 6083 { 6084 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX, 6085 VOIDmode, 0), 6086 GT, NULL_RTX, mode, unsignedp, 0, 6087 default_label); 6088 } 6089 6090 if (!node_has_low_bound (node, index_type)) 6091 { 6092 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX, 6093 VOIDmode, 0), 6094 LT, NULL_RTX, mode, unsignedp, 0, 6095 default_label); 6096 } 6097 6098 emit_jump (label_rtx (node->code_label)); 6099 } 6100 } 6101} 6102 6103/* These routines are used by the loop unrolling code. They copy BLOCK trees 6104 so that the debugging info will be correct for the unrolled loop. */ 6105 6106/* Indexed by block number, contains a pointer to the N'th block node. 6107 6108 Allocated by the call to identify_blocks, then released after the call 6109 to reorder_blocks in the function unroll_block_trees. */ 6110 6111static tree *block_vector; 6112 6113void 6114find_loop_tree_blocks () 6115{ 6116 tree block = DECL_INITIAL (current_function_decl); 6117 6118 block_vector = identify_blocks (block, get_insns ()); 6119} 6120 6121void 6122unroll_block_trees () 6123{ 6124 tree block = DECL_INITIAL (current_function_decl); 6125 6126 reorder_blocks (block_vector, block, get_insns ()); 6127 6128 /* Release any memory allocated by identify_blocks. */ 6129 if (block_vector) 6130 free (block_vector); 6131} 6132