expr.h revision 132718
1/* Definitions for code generation pass of GNU compiler.
2   Copyright (C) 1987, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3   1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
4
5This file is part of GCC.
6
7GCC is free software; you can redistribute it and/or modify it under
8the terms of the GNU General Public License as published by the Free
9Software Foundation; either version 2, or (at your option) any later
10version.
11
12GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13WARRANTY; without even the implied warranty of MERCHANTABILITY or
14FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
15for more details.
16
17You should have received a copy of the GNU General Public License
18along with GCC; see the file COPYING.  If not, write to the Free
19Software Foundation, 59 Temple Place - Suite 330, Boston, MA
2002111-1307, USA.  */
21
22/* The default branch cost is 1.  */
23#ifndef BRANCH_COST
24#define BRANCH_COST 1
25#endif
26
27/* Macros to access the slots of a QUEUED rtx.
28   Here rather than in rtl.h because only the expansion pass
29   should ever encounter a QUEUED.  */
30
31/* The variable for which an increment is queued.  */
32#define QUEUED_VAR(P) XEXP (P, 0)
33/* If the increment has been emitted, this is the insn
34   that does the increment.  It is zero before the increment is emitted.
35   If more than one insn is emitted, this is the first insn.  */
36#define QUEUED_INSN(P) XEXP (P, 1)
37/* If a pre-increment copy has been generated, this is the copy
38   (it is a temporary reg).  Zero if no copy made yet.  */
39#define QUEUED_COPY(P) XEXP (P, 2)
40/* This is the body to use for the insn to do the increment.
41   It is used to emit the increment.  */
42#define QUEUED_BODY(P) XEXP (P, 3)
43/* Next QUEUED in the queue.  */
44#define QUEUED_NEXT(P) XEXP (P, 4)
45
46/* This is the 4th arg to `expand_expr'.
47   EXPAND_STACK_PARM means we are possibly expanding a call param onto
48   the stack.  Choosing a value of 2 isn't special;  It just allows
49   some code optimization in store_expr.
50   EXPAND_SUM means it is ok to return a PLUS rtx or MULT rtx.
51   EXPAND_INITIALIZER is similar but also record any labels on forced_labels.
52   EXPAND_CONST_ADDRESS means it is ok to return a MEM whose address
53    is a constant that is not a legitimate address.
54   EXPAND_WRITE means we are only going to write to the resulting rtx.
55   EXPAND_MEMORY means we are interested in a memory result, even if
56    the memory is constant and we could have propagated a constant value.  */
57enum expand_modifier {EXPAND_NORMAL = 0, EXPAND_STACK_PARM = 2, EXPAND_SUM,
58		      EXPAND_CONST_ADDRESS, EXPAND_INITIALIZER, EXPAND_WRITE,
59		      EXPAND_MEMORY};
60
61/* Prevent the compiler from deferring stack pops.  See
62   inhibit_defer_pop for more information.  */
63#define NO_DEFER_POP (inhibit_defer_pop += 1)
64
65/* Allow the compiler to defer stack pops.  See inhibit_defer_pop for
66   more information.  */
67#define OK_DEFER_POP (inhibit_defer_pop -= 1)
68
69/* If a memory-to-memory move would take MOVE_RATIO or more simple
70   move-instruction sequences, we will do a movstr or libcall instead.  */
71
72#ifndef MOVE_RATIO
73#if defined (HAVE_movstrqi) || defined (HAVE_movstrhi) || defined (HAVE_movstrsi) || defined (HAVE_movstrdi) || defined (HAVE_movstrti)
74#define MOVE_RATIO 2
75#else
76/* If we are optimizing for space (-Os), cut down the default move ratio.  */
77#define MOVE_RATIO (optimize_size ? 3 : 15)
78#endif
79#endif
80
81/* If a clear memory operation would take CLEAR_RATIO or more simple
82   move-instruction sequences, we will do a clrstr or libcall instead.  */
83
84#ifndef CLEAR_RATIO
85#if defined (HAVE_clrstrqi) || defined (HAVE_clrstrhi) || defined (HAVE_clrstrsi) || defined (HAVE_clrstrdi) || defined (HAVE_clrstrti)
86#define CLEAR_RATIO 2
87#else
88/* If we are optimizing for space, cut down the default clear ratio.  */
89#define CLEAR_RATIO (optimize_size ? 3 : 15)
90#endif
91#endif
92
93enum direction {none, upward, downward};
94
95/* Structure to record the size of a sequence of arguments
96   as the sum of a tree-expression and a constant.  This structure is
97   also used to store offsets from the stack, which might be negative,
98   so the variable part must be ssizetype, not sizetype.  */
99
100struct args_size
101{
102  HOST_WIDE_INT constant;
103  tree var;
104};
105
106/* Package up various arg related fields of struct args for
107   locate_and_pad_parm.  */
108struct locate_and_pad_arg_data
109{
110  /* Size of this argument on the stack, rounded up for any padding it
111     gets.  If REG_PARM_STACK_SPACE is defined, then register parms are
112     counted here, otherwise they aren't.  */
113  struct args_size size;
114  /* Offset of this argument from beginning of stack-args.  */
115  struct args_size offset;
116  /* Offset to the start of the stack slot.  Different from OFFSET
117     if this arg pads downward.  */
118  struct args_size slot_offset;
119  /* The amount that the stack pointer needs to be adjusted to
120     force alignment for the next argument.  */
121  struct args_size alignment_pad;
122  /* Which way we should pad this arg.  */
123  enum direction where_pad;
124};
125
126/* Add the value of the tree INC to the `struct args_size' TO.  */
127
128#define ADD_PARM_SIZE(TO, INC)				\
129do {							\
130  tree inc = (INC);					\
131  if (host_integerp (inc, 0))				\
132    (TO).constant += tree_low_cst (inc, 0);		\
133  else if ((TO).var == 0)				\
134    (TO).var = convert (ssizetype, inc);		\
135  else							\
136    (TO).var = size_binop (PLUS_EXPR, (TO).var,		\
137			   convert (ssizetype, inc));	\
138} while (0)
139
140#define SUB_PARM_SIZE(TO, DEC)				\
141do {							\
142  tree dec = (DEC);					\
143  if (host_integerp (dec, 0))				\
144    (TO).constant -= tree_low_cst (dec, 0);		\
145  else if ((TO).var == 0)				\
146    (TO).var = size_binop (MINUS_EXPR, ssize_int (0),	\
147			   convert (ssizetype, dec));	\
148  else							\
149    (TO).var = size_binop (MINUS_EXPR, (TO).var,	\
150			   convert (ssizetype, dec));	\
151} while (0)
152
153/* Convert the implicit sum in a `struct args_size' into a tree
154   of type ssizetype.  */
155#define ARGS_SIZE_TREE(SIZE)					\
156((SIZE).var == 0 ? ssize_int ((SIZE).constant)			\
157 : size_binop (PLUS_EXPR, convert (ssizetype, (SIZE).var),	\
158	       ssize_int ((SIZE).constant)))
159
160/* Convert the implicit sum in a `struct args_size' into an rtx.  */
161#define ARGS_SIZE_RTX(SIZE)					\
162((SIZE).var == 0 ? GEN_INT ((SIZE).constant)			\
163 : expand_expr (ARGS_SIZE_TREE (SIZE), NULL_RTX, VOIDmode, 0))
164
165/* Supply a default definition for FUNCTION_ARG_PADDING:
166   usually pad upward, but pad short args downward on
167   big-endian machines.  */
168
169#define DEFAULT_FUNCTION_ARG_PADDING(MODE, TYPE)			\
170  (! BYTES_BIG_ENDIAN							\
171   ? upward								\
172   : (((MODE) == BLKmode						\
173       ? ((TYPE) && TREE_CODE (TYPE_SIZE (TYPE)) == INTEGER_CST		\
174	  && int_size_in_bytes (TYPE) < (PARM_BOUNDARY / BITS_PER_UNIT)) \
175       : GET_MODE_BITSIZE (MODE) < PARM_BOUNDARY)			\
176      ? downward : upward))
177
178#ifndef FUNCTION_ARG_PADDING
179#define FUNCTION_ARG_PADDING(MODE, TYPE)	\
180  DEFAULT_FUNCTION_ARG_PADDING ((MODE), (TYPE))
181#endif
182
183/* Supply a default definition for FUNCTION_ARG_BOUNDARY.  Normally, we let
184   FUNCTION_ARG_PADDING, which also pads the length, handle any needed
185   alignment.  */
186
187#ifndef FUNCTION_ARG_BOUNDARY
188#define FUNCTION_ARG_BOUNDARY(MODE, TYPE)	PARM_BOUNDARY
189#endif
190
191tree split_complex_types (tree);
192tree split_complex_values (tree);
193
194/* Nonzero if we do not know how to pass TYPE solely in registers.  */
195extern bool default_must_pass_in_stack (enum machine_mode, tree);
196#ifndef MUST_PASS_IN_STACK
197#define MUST_PASS_IN_STACK(MODE,TYPE) default_must_pass_in_stack(MODE, TYPE)
198#endif
199
200/* Supply a default definition of STACK_SAVEAREA_MODE for emit_stack_save.
201   Normally move_insn, so Pmode stack pointer.  */
202
203#ifndef STACK_SAVEAREA_MODE
204#define STACK_SAVEAREA_MODE(LEVEL) Pmode
205#endif
206
207/* Supply a default definition of STACK_SIZE_MODE for
208   allocate_dynamic_stack_space.  Normally PLUS/MINUS, so word_mode.  */
209
210#ifndef STACK_SIZE_MODE
211#define STACK_SIZE_MODE word_mode
212#endif
213
214/* Provide default values for the macros controlling stack checking.  */
215
216#ifndef STACK_CHECK_BUILTIN
217#define STACK_CHECK_BUILTIN 0
218#endif
219
220/* The default interval is one page.  */
221#ifndef STACK_CHECK_PROBE_INTERVAL
222#define STACK_CHECK_PROBE_INTERVAL 4096
223#endif
224
225/* The default is to do a store into the stack.  */
226#ifndef STACK_CHECK_PROBE_LOAD
227#define STACK_CHECK_PROBE_LOAD 0
228#endif
229
230/* This value is arbitrary, but should be sufficient for most machines.  */
231#ifndef STACK_CHECK_PROTECT
232#define STACK_CHECK_PROTECT (75 * UNITS_PER_WORD)
233#endif
234
235/* Make the maximum frame size be the largest we can and still only need
236   one probe per function.  */
237#ifndef STACK_CHECK_MAX_FRAME_SIZE
238#define STACK_CHECK_MAX_FRAME_SIZE \
239  (STACK_CHECK_PROBE_INTERVAL - UNITS_PER_WORD)
240#endif
241
242/* This is arbitrary, but should be large enough everywhere.  */
243#ifndef STACK_CHECK_FIXED_FRAME_SIZE
244#define STACK_CHECK_FIXED_FRAME_SIZE (4 * UNITS_PER_WORD)
245#endif
246
247/* Provide a reasonable default for the maximum size of an object to
248   allocate in the fixed frame.  We may need to be able to make this
249   controllable by the user at some point.  */
250#ifndef STACK_CHECK_MAX_VAR_SIZE
251#define STACK_CHECK_MAX_VAR_SIZE (STACK_CHECK_MAX_FRAME_SIZE / 100)
252#endif
253
254/* Functions from optabs.c, commonly used, and without need for the optabs
255   tables:  */
256
257/* Passed to expand_simple_binop and expand_binop to say which options
258   to try to use if the requested operation can't be open-coded on the
259   requisite mode.  Either OPTAB_LIB or OPTAB_LIB_WIDEN says try using
260   a library call.  Either OPTAB_WIDEN or OPTAB_LIB_WIDEN says try
261   using a wider mode.  OPTAB_MUST_WIDEN says try widening and don't
262   try anything else.  */
263
264enum optab_methods
265{
266  OPTAB_DIRECT,
267  OPTAB_LIB,
268  OPTAB_WIDEN,
269  OPTAB_LIB_WIDEN,
270  OPTAB_MUST_WIDEN
271};
272
273/* Generate code for a simple binary or unary operation.  "Simple" in
274   this case means "can be unambiguously described by a (mode, code)
275   pair and mapped to a single optab."  */
276extern rtx expand_simple_binop (enum machine_mode, enum rtx_code, rtx,
277				rtx, rtx, int, enum optab_methods);
278extern rtx expand_simple_unop (enum machine_mode, enum rtx_code, rtx, rtx,
279			       int);
280
281/* Report whether the machine description contains an insn which can
282   perform the operation described by CODE and MODE.  */
283extern int have_insn_for (enum rtx_code, enum machine_mode);
284
285/* Emit code to make a call to a constant function or a library call.  */
286extern void emit_libcall_block (rtx, rtx, rtx, rtx);
287
288/* Create but don't emit one rtl instruction to perform certain operations.
289   Modes must match; operands must meet the operation's predicates.
290   Likewise for subtraction and for just copying.
291   These do not call protect_from_queue; caller must do so.  */
292extern rtx gen_add2_insn (rtx, rtx);
293extern rtx gen_add3_insn (rtx, rtx, rtx);
294extern rtx gen_sub2_insn (rtx, rtx);
295extern rtx gen_sub3_insn (rtx, rtx, rtx);
296extern rtx gen_move_insn (rtx, rtx);
297extern int have_add2_insn (rtx, rtx);
298extern int have_sub2_insn (rtx, rtx);
299
300/* Emit a pair of rtl insns to compare two rtx's and to jump
301   to a label if the comparison is true.  */
302extern void emit_cmp_and_jump_insns (rtx, rtx, enum rtx_code, rtx,
303				     enum machine_mode, int, rtx);
304
305/* Generate code to indirectly jump to a location given in the rtx LOC.  */
306extern void emit_indirect_jump (rtx);
307
308#ifdef HAVE_conditional_move
309/* Emit a conditional move operation.  */
310rtx emit_conditional_move (rtx, enum rtx_code, rtx, rtx, enum machine_mode,
311			   rtx, rtx, enum machine_mode, int);
312
313/* Return nonzero if the conditional move is supported.  */
314int can_conditionally_move_p (enum machine_mode mode);
315
316#endif
317rtx emit_conditional_add (rtx, enum rtx_code, rtx, rtx, enum machine_mode,
318			  rtx, rtx, enum machine_mode, int);
319
320
321/* Functions from expmed.c:  */
322
323/* Arguments MODE, RTX: return an rtx for the negation of that value.
324   May emit insns.  */
325extern rtx negate_rtx (enum machine_mode, rtx);
326
327/* Expand a logical AND operation.  */
328extern rtx expand_and (enum machine_mode, rtx, rtx, rtx);
329
330/* Emit a store-flag operation.  */
331extern rtx emit_store_flag (rtx, enum rtx_code, rtx, rtx, enum machine_mode,
332			    int, int);
333
334/* Like emit_store_flag, but always succeeds.  */
335extern rtx emit_store_flag_force (rtx, enum rtx_code, rtx, rtx,
336				  enum machine_mode, int, int);
337
338/* Functions from loop.c:  */
339
340/* Given an insn and condition, return a canonical description of
341   the test being made.  */
342extern rtx canonicalize_condition (rtx, rtx, int, rtx *, rtx, int);
343
344/* Given a JUMP_INSN, return a canonical description of the test
345   being made.  */
346extern rtx get_condition (rtx, rtx *, int);
347
348/* Generate a conditional trap instruction.  */
349extern rtx gen_cond_trap (enum rtx_code, rtx, rtx, rtx);
350
351/* Functions from builtins.c:  */
352extern rtx expand_builtin (tree, rtx, rtx, enum machine_mode, int);
353extern tree std_build_builtin_va_list (void);
354extern void std_expand_builtin_va_start (tree, rtx);
355extern rtx std_expand_builtin_va_arg (tree, tree);
356extern rtx expand_builtin_va_arg (tree, tree);
357extern rtx default_expand_builtin (tree, rtx, rtx, enum machine_mode, int);
358extern void expand_builtin_setjmp_setup (rtx, rtx);
359extern void expand_builtin_setjmp_receiver (rtx);
360extern void expand_builtin_longjmp (rtx, rtx);
361extern rtx expand_builtin_saveregs (void);
362extern void expand_builtin_trap (void);
363extern HOST_WIDE_INT get_varargs_alias_set (void);
364extern HOST_WIDE_INT get_frame_alias_set (void);
365extern void record_base_value (unsigned int, rtx, int);
366extern void record_alias_subset (HOST_WIDE_INT, HOST_WIDE_INT);
367extern HOST_WIDE_INT new_alias_set (void);
368extern int can_address_p (tree);
369
370/* Functions from expr.c:  */
371
372/* This is run once per compilation to set up which modes can be used
373   directly in memory and to initialize the block move optab.  */
374extern void init_expr_once (void);
375
376/* This is run at the start of compiling a function.  */
377extern void init_expr (void);
378
379/* This is run at the end of compiling a function.  */
380extern void finish_expr_for_function (void);
381
382/* Use protect_from_queue to convert a QUEUED expression
383   into something that you can put immediately into an instruction.  */
384extern rtx protect_from_queue (rtx, int);
385
386/* Perform all the pending incrementations.  */
387extern void emit_queue (void);
388
389/* Tell if something has a queued subexpression.  */
390extern int queued_subexp_p (rtx);
391
392/* Emit some rtl insns to move data between rtx's, converting machine modes.
393   Both modes must be floating or both fixed.  */
394extern void convert_move (rtx, rtx, int);
395
396/* Convert an rtx to specified machine mode and return the result.  */
397extern rtx convert_to_mode (enum machine_mode, rtx, int);
398
399/* Convert an rtx to MODE from OLDMODE and return the result.  */
400extern rtx convert_modes (enum machine_mode, enum machine_mode, rtx, int);
401
402/* Emit code to move a block Y to a block X.  */
403
404enum block_op_methods
405{
406  BLOCK_OP_NORMAL,
407  BLOCK_OP_NO_LIBCALL,
408  BLOCK_OP_CALL_PARM
409};
410
411extern void init_block_move_fn (const char *);
412extern void init_block_clear_fn (const char *);
413
414extern rtx emit_block_move (rtx, rtx, rtx, enum block_op_methods);
415
416/* Copy all or part of a value X into registers starting at REGNO.
417   The number of registers to be filled is NREGS.  */
418extern void move_block_to_reg (int, rtx, int, enum machine_mode);
419
420/* Copy all or part of a BLKmode value X out of registers starting at REGNO.
421   The number of registers to be filled is NREGS.  */
422extern void move_block_from_reg (int, rtx, int);
423
424/* Generate a non-consecutive group of registers represented by a PARALLEL.  */
425extern rtx gen_group_rtx (rtx);
426
427/* Load a BLKmode value into non-consecutive registers represented by a
428   PARALLEL.  */
429extern void emit_group_load (rtx, rtx, tree, int);
430
431/* Move a non-consecutive group of registers represented by a PARALLEL into
432   a non-consecutive group of registers represented by a PARALLEL.  */
433extern void emit_group_move (rtx, rtx);
434
435/* Store a BLKmode value from non-consecutive registers represented by a
436   PARALLEL.  */
437extern void emit_group_store (rtx, rtx, tree, int);
438
439/* Copy BLKmode object from a set of registers.  */
440extern rtx copy_blkmode_from_reg (rtx, rtx, tree);
441
442/* Mark REG as holding a parameter for the next CALL_INSN.  */
443extern void use_reg (rtx *, rtx);
444
445/* Mark NREGS consecutive regs, starting at REGNO, as holding parameters
446   for the next CALL_INSN.  */
447extern void use_regs (rtx *, int, int);
448
449/* Mark a PARALLEL as holding a parameter for the next CALL_INSN.  */
450extern void use_group_regs (rtx *, rtx);
451
452/* Write zeros through the storage of OBJECT.
453   If OBJECT has BLKmode, SIZE is its length in bytes.  */
454extern rtx clear_storage (rtx, rtx);
455
456/* Determine whether the LEN bytes can be moved by using several move
457   instructions.  Return nonzero if a call to move_by_pieces should
458   succeed.  */
459extern int can_move_by_pieces (unsigned HOST_WIDE_INT, unsigned int);
460
461/* Return nonzero if it is desirable to store LEN bytes generated by
462   CONSTFUN with several move instructions by store_by_pieces
463   function.  CONSTFUNDATA is a pointer which will be passed as argument
464   in every CONSTFUN call.
465   ALIGN is maximum alignment we can assume.  */
466extern int can_store_by_pieces (unsigned HOST_WIDE_INT,
467				rtx (*) (void *, HOST_WIDE_INT,
468					 enum machine_mode),
469				void *, unsigned int);
470
471/* Generate several move instructions to store LEN bytes generated by
472   CONSTFUN to block TO.  (A MEM rtx with BLKmode).  CONSTFUNDATA is a
473   pointer which will be passed as argument in every CONSTFUN call.
474   ALIGN is maximum alignment we can assume.
475   Returns TO + LEN.  */
476extern rtx store_by_pieces (rtx, unsigned HOST_WIDE_INT,
477			    rtx (*) (void *, HOST_WIDE_INT, enum machine_mode),
478			    void *, unsigned int, int);
479
480/* Emit insns to set X from Y.  */
481extern rtx emit_move_insn (rtx, rtx);
482
483/* Emit insns to set X from Y, with no frills.  */
484extern rtx emit_move_insn_1 (rtx, rtx);
485
486/* Push a block of length SIZE (perhaps variable)
487   and return an rtx to address the beginning of the block.  */
488extern rtx push_block (rtx, int, int);
489
490/* Generate code to push something onto the stack, given its mode and type.  */
491extern void emit_push_insn (rtx, enum machine_mode, tree, rtx, unsigned int,
492			    int, rtx, int, rtx, rtx, int, rtx);
493
494/* Expand an assignment that stores the value of FROM into TO.  */
495extern rtx expand_assignment (tree, tree, int);
496
497/* Generate code for computing expression EXP,
498   and storing the value into TARGET.
499   If SUGGEST_REG is nonzero, copy the value through a register
500   and return that register, if that is possible.  */
501extern rtx store_expr (tree, rtx, int);
502
503/* Given an rtx that may include add and multiply operations,
504   generate them as insns and return a pseudo-reg containing the value.
505   Useful after calling expand_expr with 1 as sum_ok.  */
506extern rtx force_operand (rtx, rtx);
507
508/* Return an object on the placeholder list that matches EXP, a
509   PLACEHOLDER_EXPR.  An object "matches" if it is of the type of the
510   PLACEHOLDER_EXPR or a pointer type to it.  For further information, see
511   tree.def.  If no such object is found, abort.  If PLIST is nonzero, it is
512   a location which initially points to a starting location in the
513   placeholder list (zero means start of the list) and where a pointer into
514   the placeholder list at which the object is found is placed.  */
515extern tree find_placeholder (tree, tree *);
516
517/* Generate code for computing expression EXP.
518   An rtx for the computed value is returned.  The value is never null.
519   In the case of a void EXP, const0_rtx is returned.  */
520#define expand_expr(EXP, TARGET, MODE, MODIFIER) \
521  expand_expr_real((EXP), (TARGET), (MODE), (MODIFIER), NULL)
522extern rtx expand_expr_real (tree, rtx, enum machine_mode,
523			     enum expand_modifier, rtx *);
524
525/* At the start of a function, record that we have no previously-pushed
526   arguments waiting to be popped.  */
527extern void init_pending_stack_adjust (void);
528
529/* When exiting from function, if safe, clear out any pending stack adjust
530   so the adjustment won't get done.  */
531extern void clear_pending_stack_adjust (void);
532
533/* Pop any previously-pushed arguments that have not been popped yet.  */
534extern void do_pending_stack_adjust (void);
535
536/* Return the tree node and offset if a given argument corresponds to
537   a string constant.  */
538extern tree string_constant (tree, tree *);
539
540/* Generate code to evaluate EXP and jump to LABEL if the value is zero.  */
541extern void jumpifnot (tree, rtx);
542
543/* Generate code to evaluate EXP and jump to LABEL if the value is nonzero.  */
544extern void jumpif (tree, rtx);
545
546/* Generate code to evaluate EXP and jump to IF_FALSE_LABEL if
547   the result is zero, or IF_TRUE_LABEL if the result is one.  */
548extern void do_jump (tree, rtx, rtx);
549
550/* Generate rtl to compare two rtx's, will call emit_cmp_insn.  */
551extern rtx compare_from_rtx (rtx, rtx, enum rtx_code, int, enum machine_mode,
552			     rtx);
553extern void do_compare_rtx_and_jump (rtx, rtx, enum rtx_code, int,
554				     enum machine_mode, rtx, rtx, rtx);
555
556/* Two different ways of generating switch statements.  */
557extern int try_casesi (tree, tree, tree, tree, rtx, rtx);
558extern int try_tablejump (tree, tree, tree, tree, rtx, rtx);
559
560/* Smallest number of adjacent cases before we use a jump table.
561   XXX Should be a target hook.  */
562extern unsigned int case_values_threshold (void);
563
564
565/* rtl.h and tree.h were included.  */
566/* Return an rtx for the size in bytes of the value of an expr.  */
567extern rtx expr_size (tree);
568
569/* Return a wide integer for the size in bytes of the value of EXP, or -1
570   if the size can vary or is larger than an integer.  */
571extern HOST_WIDE_INT int_expr_size (tree);
572
573extern rtx lookup_static_chain (tree);
574
575/* Convert a stack slot address ADDR valid in function FNDECL
576   into an address valid in this function (using a static chain).  */
577extern rtx fix_lexical_addr (rtx, tree);
578
579/* Return the address of the trampoline for entering nested fn FUNCTION.  */
580extern rtx trampoline_address (tree);
581
582/* Return an rtx that refers to the value returned by a function
583   in its original home.  This becomes invalid if any more code is emitted.  */
584extern rtx hard_function_value (tree, tree, int);
585
586extern rtx prepare_call_address (rtx, tree, rtx *, int, int);
587
588extern rtx expand_call (tree, rtx, int);
589
590#ifdef TREE_CODE
591extern rtx expand_shift (enum tree_code, enum machine_mode, rtx, tree, rtx,
592			 int);
593extern rtx expand_divmod (int, enum tree_code, enum machine_mode, rtx, rtx,
594			  rtx, int);
595#endif
596
597extern void locate_and_pad_parm (enum machine_mode, tree, int, int, tree,
598				 struct args_size *,
599				 struct locate_and_pad_arg_data *);
600extern rtx expand_inline_function (tree, tree, rtx, int, tree, rtx);
601
602/* Return the CODE_LABEL rtx for a LABEL_DECL, creating it if necessary.  */
603extern rtx label_rtx (tree);
604
605/* As label_rtx, but additionally the label is placed on the forced label
606   list of its containing function (i.e. it is treated as reachable even
607   if how is not obvious).  */
608extern rtx force_label_rtx (tree);
609
610/* Indicate how an input argument register was promoted.  */
611extern rtx promoted_input_arg (unsigned int, enum machine_mode *, int *);
612
613/* Return an rtx like arg but sans any constant terms.
614   Returns the original rtx if it has no constant terms.
615   The constant terms are added and stored via a second arg.  */
616extern rtx eliminate_constant_term (rtx, rtx *);
617
618/* Convert arg to a valid memory address for specified machine mode,
619   by emitting insns to perform arithmetic if nec.  */
620extern rtx memory_address (enum machine_mode, rtx);
621
622/* Like `memory_address' but pretent `flag_force_addr' is 0.  */
623extern rtx memory_address_noforce (enum machine_mode, rtx);
624
625/* Set the alias set of MEM to SET.  */
626extern void set_mem_alias_set (rtx, HOST_WIDE_INT);
627
628/* Set the alignment of MEM to ALIGN bits.  */
629extern void set_mem_align (rtx, unsigned int);
630
631/* Set the expr for MEM to EXPR.  */
632extern void set_mem_expr (rtx, tree);
633
634/* Set the offset for MEM to OFFSET.  */
635extern void set_mem_offset (rtx, rtx);
636
637/* Set the size for MEM to SIZE.  */
638extern void set_mem_size (rtx, rtx);
639
640/* Return a memory reference like MEMREF, but with its mode changed
641   to MODE and its address changed to ADDR.
642   (VOIDmode means don't change the mode.
643   NULL for ADDR means don't change the address.)  */
644extern rtx change_address (rtx, enum machine_mode, rtx);
645
646/* Return a memory reference like MEMREF, but with its mode changed
647   to MODE and its address offset by OFFSET bytes.  */
648#define adjust_address(MEMREF, MODE, OFFSET) \
649  adjust_address_1 (MEMREF, MODE, OFFSET, 1, 1)
650
651/* Likewise, but the reference is not required to be valid.  */
652#define adjust_address_nv(MEMREF, MODE, OFFSET) \
653  adjust_address_1 (MEMREF, MODE, OFFSET, 0, 1)
654
655/* Return a memory reference like MEMREF, but with its mode changed
656   to MODE and its address changed to ADDR, which is assumed to be
657   increased by OFFSET bytes from MEMREF.  */
658#define adjust_automodify_address(MEMREF, MODE, ADDR, OFFSET) \
659  adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 1)
660
661/* Likewise, but the reference is not required to be valid.  */
662#define adjust_automodify_address_nv(MEMREF, MODE, ADDR, OFFSET) \
663  adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 0)
664
665extern rtx adjust_address_1 (rtx, enum machine_mode, HOST_WIDE_INT, int, int);
666extern rtx adjust_automodify_address_1 (rtx, enum machine_mode, rtx,
667					HOST_WIDE_INT, int);
668
669/* Return a memory reference like MEMREF, but whose address is changed by
670   adding OFFSET, an RTX, to it.  POW2 is the highest power of two factor
671   known to be in OFFSET (possibly 1).  */
672extern rtx offset_address (rtx, rtx, unsigned HOST_WIDE_INT);
673
674/* Return a memory reference like MEMREF, but with its address changed to
675   ADDR.  The caller is asserting that the actual piece of memory pointed
676   to is the same, just the form of the address is being changed, such as
677   by putting something into a register.  */
678extern rtx replace_equiv_address (rtx, rtx);
679
680/* Likewise, but the reference is not required to be valid.  */
681extern rtx replace_equiv_address_nv (rtx, rtx);
682
683/* Return a memory reference like MEMREF, but with its mode widened to
684   MODE and adjusted by OFFSET.  */
685extern rtx widen_memory_access (rtx, enum machine_mode, HOST_WIDE_INT);
686
687/* Return a memory reference like MEMREF, but which is known to have a
688   valid address.  */
689extern rtx validize_mem (rtx);
690
691/* Given REF, either a MEM or a REG, and T, either the type of X or
692   the expression corresponding to REF, set RTX_UNCHANGING_P if
693   appropriate.  */
694extern void maybe_set_unchanging (rtx, tree);
695
696/* Given REF, a MEM, and T, either the type of X or the expression
697   corresponding to REF, set the memory attributes.  OBJECTP is nonzero
698   if we are making a new object of this type.  */
699extern void set_mem_attributes (rtx, tree, int);
700
701/* Similar, except that BITPOS has not yet been applied to REF, so if
702   we alter MEM_OFFSET according to T then we should subtract BITPOS
703   expecting that it'll be added back in later.  */
704extern void set_mem_attributes_minus_bitpos (rtx, tree, int, HOST_WIDE_INT);
705
706/* Assemble the static constant template for function entry trampolines.  */
707extern rtx assemble_trampoline_template (void);
708
709/* Given rtx, return new rtx whose address won't be affected by
710   any side effects.  It has been copied to a new temporary reg.  */
711extern rtx stabilize (rtx);
712
713/* Given an rtx, copy all regs it refers to into new temps
714   and return a modified copy that refers to the new temps.  */
715extern rtx copy_all_regs (rtx);
716
717/* Copy given rtx to a new temp reg and return that.  */
718extern rtx copy_to_reg (rtx);
719
720/* Like copy_to_reg but always make the reg Pmode.  */
721extern rtx copy_addr_to_reg (rtx);
722
723/* Like copy_to_reg but always make the reg the specified mode MODE.  */
724extern rtx copy_to_mode_reg (enum machine_mode, rtx);
725
726/* Copy given rtx to given temp reg and return that.  */
727extern rtx copy_to_suggested_reg (rtx, rtx, enum machine_mode);
728
729/* Copy a value to a register if it isn't already a register.
730   Args are mode (in case value is a constant) and the value.  */
731extern rtx force_reg (enum machine_mode, rtx);
732
733/* Return given rtx, copied into a new temp reg if it was in memory.  */
734extern rtx force_not_mem (rtx);
735
736/* Return mode and signedness to use when object is promoted.  */
737extern enum machine_mode promote_mode (tree, enum machine_mode, int *, int);
738
739/* Remove some bytes from the stack.  An rtx says how many.  */
740extern void adjust_stack (rtx);
741
742/* Add some bytes to the stack.  An rtx says how many.  */
743extern void anti_adjust_stack (rtx);
744
745/* This enum is used for the following two functions.  */
746enum save_level {SAVE_BLOCK, SAVE_FUNCTION, SAVE_NONLOCAL};
747
748/* Save the stack pointer at the specified level.  */
749extern void emit_stack_save (enum save_level, rtx *, rtx);
750
751/* Restore the stack pointer from a save area of the specified level.  */
752extern void emit_stack_restore (enum save_level, rtx, rtx);
753
754/* Allocate some space on the stack dynamically and return its address.  An rtx
755   says how many bytes.  */
756extern rtx allocate_dynamic_stack_space (rtx, rtx, int);
757
758/* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
759   FIRST is a constant and size is a Pmode RTX.  These are offsets from the
760   current stack pointer.  STACK_GROWS_DOWNWARD says whether to add or
761   subtract from the stack.  If SIZE is constant, this is done
762   with a fixed number of probes.  Otherwise, we must make a loop.  */
763extern void probe_stack_range (HOST_WIDE_INT, rtx);
764
765/* Return an rtx that refers to the value returned by a library call
766   in its original home.  This becomes invalid if any more code is emitted.  */
767extern rtx hard_libcall_value (enum machine_mode);
768
769/* Given an rtx, return an rtx for a value rounded up to a multiple
770   of STACK_BOUNDARY / BITS_PER_UNIT.  */
771extern rtx round_push (rtx);
772
773/* Return the mode desired by operand N of a particular bitfield
774   insert/extract insn, or MAX_MACHINE_MODE if no such insn is
775   available.  */
776
777enum extraction_pattern { EP_insv, EP_extv, EP_extzv };
778extern enum machine_mode
779mode_for_extraction (enum extraction_pattern, int);
780
781extern rtx store_bit_field (rtx, unsigned HOST_WIDE_INT,
782			    unsigned HOST_WIDE_INT, enum machine_mode, rtx,
783			    HOST_WIDE_INT);
784extern rtx extract_bit_field (rtx, unsigned HOST_WIDE_INT,
785			      unsigned HOST_WIDE_INT, int, rtx,
786			      enum machine_mode, enum machine_mode,
787			      HOST_WIDE_INT);
788extern rtx expand_mult (enum machine_mode, rtx, rtx, rtx, int);
789extern bool const_mult_add_overflow_p (rtx, rtx, rtx, enum machine_mode, int);
790extern rtx expand_mult_add (rtx, rtx, rtx, rtx,enum machine_mode, int);
791extern rtx expand_mult_highpart_adjust (enum machine_mode, rtx, rtx, rtx, rtx, int);
792
793extern rtx assemble_static_space (unsigned HOST_WIDE_INT);
794extern int safe_from_p (rtx, tree, int);
795
796/* Call this once to initialize the contents of the optabs
797   appropriately for the current target machine.  */
798extern void init_optabs (void);
799extern void init_all_optabs (void);
800
801/* Call this to initialize an optab function entry.  */
802extern rtx init_one_libfunc (const char *);
803
804extern void do_jump_by_parts_equality_rtx (rtx, rtx, rtx);
805extern void do_jump_by_parts_greater_rtx (enum machine_mode, int, rtx, rtx,
806					  rtx, rtx);
807
808extern void mark_seen_cases (tree, unsigned char *, HOST_WIDE_INT, int);
809
810extern int vector_mode_valid_p (enum machine_mode);
811
812extern tree placeholder_list;
813