expr.h revision 96489
1/* Definitions for code generation pass of GNU compiler.
2   Copyright (C) 1987, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3   1999, 2000 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_SUM means it is ok to return a PLUS rtx or MULT rtx.
48   EXPAND_INITIALIZER is similar but also record any labels on forced_labels.
49   EXPAND_CONST_ADDRESS means it is ok to return a MEM whose address
50    is a constant that is not a legitimate address.
51   EXPAND_WRITE means we are only going to write to the resulting rtx.  */
52enum expand_modifier {EXPAND_NORMAL, EXPAND_SUM, EXPAND_CONST_ADDRESS,
53			EXPAND_INITIALIZER, EXPAND_WRITE};
54
55/* Prevent the compiler from deferring stack pops.  See
56   inhibit_defer_pop for more information.  */
57#define NO_DEFER_POP (inhibit_defer_pop += 1)
58
59/* Allow the compiler to defer stack pops.  See inhibit_defer_pop for
60   more information.  */
61#define OK_DEFER_POP (inhibit_defer_pop -= 1)
62
63#ifdef TREE_CODE /* Don't lose if tree.h not included.  */
64/* Structure to record the size of a sequence of arguments
65   as the sum of a tree-expression and a constant.  This structure is
66   also used to store offsets from the stack, which might be negative,
67   so the variable part must be ssizetype, not sizetype.  */
68
69struct args_size
70{
71  HOST_WIDE_INT constant;
72  tree var;
73};
74#endif
75
76/* Add the value of the tree INC to the `struct args_size' TO.  */
77
78#define ADD_PARM_SIZE(TO, INC)				\
79do {							\
80  tree inc = (INC);					\
81  if (host_integerp (inc, 0))				\
82    (TO).constant += tree_low_cst (inc, 0);		\
83  else if ((TO).var == 0)				\
84    (TO).var = convert (ssizetype, inc);		\
85  else							\
86    (TO).var = size_binop (PLUS_EXPR, (TO).var,		\
87			   convert (ssizetype, inc));	\
88} while (0)
89
90#define SUB_PARM_SIZE(TO, DEC)				\
91do {							\
92  tree dec = (DEC);					\
93  if (host_integerp (dec, 0))				\
94    (TO).constant -= tree_low_cst (dec, 0);		\
95  else if ((TO).var == 0)				\
96    (TO).var = size_binop (MINUS_EXPR, ssize_int (0),	\
97			   convert (ssizetype, dec));	\
98  else							\
99    (TO).var = size_binop (MINUS_EXPR, (TO).var,	\
100			   convert (ssizetype, dec));	\
101} while (0)
102
103/* Convert the implicit sum in a `struct args_size' into a tree
104   of type ssizetype.  */
105#define ARGS_SIZE_TREE(SIZE)					\
106((SIZE).var == 0 ? ssize_int ((SIZE).constant)			\
107 : size_binop (PLUS_EXPR, convert (ssizetype, (SIZE).var),	\
108	       ssize_int ((SIZE).constant)))
109
110/* Convert the implicit sum in a `struct args_size' into an rtx.  */
111#define ARGS_SIZE_RTX(SIZE)					\
112((SIZE).var == 0 ? GEN_INT ((SIZE).constant)			\
113 : expand_expr (ARGS_SIZE_TREE (SIZE), NULL_RTX, VOIDmode, 0))
114
115/* Supply a default definition for FUNCTION_ARG_PADDING:
116   usually pad upward, but pad short args downward on
117   big-endian machines.  */
118
119enum direction {none, upward, downward};  /* Value has this type.  */
120
121#ifndef FUNCTION_ARG_PADDING
122#define FUNCTION_ARG_PADDING(MODE, TYPE)				\
123  (! BYTES_BIG_ENDIAN							\
124   ? upward								\
125   : (((MODE) == BLKmode						\
126       ? ((TYPE) && TREE_CODE (TYPE_SIZE (TYPE)) == INTEGER_CST		\
127	  && int_size_in_bytes (TYPE) < (PARM_BOUNDARY / BITS_PER_UNIT)) \
128       : GET_MODE_BITSIZE (MODE) < PARM_BOUNDARY)			\
129      ? downward : upward))
130#endif
131
132/* Supply a default definition for FUNCTION_ARG_BOUNDARY.  Normally, we let
133   FUNCTION_ARG_PADDING, which also pads the length, handle any needed
134   alignment.  */
135
136#ifndef FUNCTION_ARG_BOUNDARY
137#define FUNCTION_ARG_BOUNDARY(MODE, TYPE)	PARM_BOUNDARY
138#endif
139
140/* Provide a default value for STRICT_ARGUMENT_NAMING.  */
141#ifndef STRICT_ARGUMENT_NAMING
142#define STRICT_ARGUMENT_NAMING 0
143#endif
144
145/* Provide a default value for PRETEND_OUTGOING_VARARGS_NAMED.  */
146#ifdef SETUP_INCOMING_VARARGS
147#ifndef PRETEND_OUTGOING_VARARGS_NAMED
148#define PRETEND_OUTGOING_VARARGS_NAMED 1
149#endif
150#else
151/* It is an error to define PRETEND_OUTGOING_VARARGS_NAMED without
152   defining SETUP_INCOMING_VARARGS.  */
153#define PRETEND_OUTGOING_VARARGS_NAMED 0
154#endif
155
156/* Nonzero if we do not know how to pass TYPE solely in registers.
157   We cannot do so in the following cases:
158
159   - if the type has variable size
160   - if the type is marked as addressable (it is required to be constructed
161     into the stack)
162   - if the padding and mode of the type is such that a copy into a register
163     would put it into the wrong part of the register.
164
165   Which padding can't be supported depends on the byte endianness.
166
167   A value in a register is implicitly padded at the most significant end.
168   On a big-endian machine, that is the lower end in memory.
169   So a value padded in memory at the upper end can't go in a register.
170   For a little-endian machine, the reverse is true.  */
171
172#ifndef MUST_PASS_IN_STACK
173#define MUST_PASS_IN_STACK(MODE,TYPE)			\
174  ((TYPE) != 0						\
175   && (TREE_CODE (TYPE_SIZE (TYPE)) != INTEGER_CST	\
176       || TREE_ADDRESSABLE (TYPE)			\
177       || ((MODE) == BLKmode 				\
178	   && ! ((TYPE) != 0 && TREE_CODE (TYPE_SIZE (TYPE)) == INTEGER_CST \
179		 && 0 == (int_size_in_bytes (TYPE)	\
180			  % (PARM_BOUNDARY / BITS_PER_UNIT))) \
181	   && (FUNCTION_ARG_PADDING (MODE, TYPE)	\
182	       == (BYTES_BIG_ENDIAN ? upward : downward)))))
183#endif
184
185/* Nonzero if type TYPE should be returned in memory.
186   Most machines can use the following default definition.  */
187
188#ifndef RETURN_IN_MEMORY
189#define RETURN_IN_MEMORY(TYPE) (TYPE_MODE (TYPE) == BLKmode)
190#endif
191
192/* Supply a default definition of STACK_SAVEAREA_MODE for emit_stack_save.
193   Normally move_insn, so Pmode stack pointer.  */
194
195#ifndef STACK_SAVEAREA_MODE
196#define STACK_SAVEAREA_MODE(LEVEL) Pmode
197#endif
198
199/* Supply a default definition of STACK_SIZE_MODE for
200   allocate_dynamic_stack_space.  Normally PLUS/MINUS, so word_mode.  */
201
202#ifndef STACK_SIZE_MODE
203#define STACK_SIZE_MODE word_mode
204#endif
205
206/* Provide default values for the macros controlling stack checking.  */
207
208#ifndef STACK_CHECK_BUILTIN
209#define STACK_CHECK_BUILTIN 0
210#endif
211
212/* The default interval is one page.  */
213#ifndef STACK_CHECK_PROBE_INTERVAL
214#define STACK_CHECK_PROBE_INTERVAL 4096
215#endif
216
217/* The default is to do a store into the stack.  */
218#ifndef STACK_CHECK_PROBE_LOAD
219#define STACK_CHECK_PROBE_LOAD 0
220#endif
221
222/* This value is arbitrary, but should be sufficient for most machines.  */
223#ifndef STACK_CHECK_PROTECT
224#define STACK_CHECK_PROTECT (75 * UNITS_PER_WORD)
225#endif
226
227/* Make the maximum frame size be the largest we can and still only need
228   one probe per function.  */
229#ifndef STACK_CHECK_MAX_FRAME_SIZE
230#define STACK_CHECK_MAX_FRAME_SIZE \
231  (STACK_CHECK_PROBE_INTERVAL - UNITS_PER_WORD)
232#endif
233
234/* This is arbitrary, but should be large enough everywhere.  */
235#ifndef STACK_CHECK_FIXED_FRAME_SIZE
236#define STACK_CHECK_FIXED_FRAME_SIZE (4 * UNITS_PER_WORD)
237#endif
238
239/* Provide a reasonable default for the maximum size of an object to
240   allocate in the fixed frame.  We may need to be able to make this
241   controllable by the user at some point.  */
242#ifndef STACK_CHECK_MAX_VAR_SIZE
243#define STACK_CHECK_MAX_VAR_SIZE (STACK_CHECK_MAX_FRAME_SIZE / 100)
244#endif
245
246/* Functions from optabs.c, commonly used, and without need for the optabs
247   tables:  */
248
249/* Passed to expand_simple_binop and expand_binop to say which options
250   to try to use if the requested operation can't be open-coded on the
251   requisite mode.  Either OPTAB_LIB or OPTAB_LIB_WIDEN says try using
252   a library call.  Either OPTAB_WIDEN or OPTAB_LIB_WIDEN says try
253   using a wider mode.  OPTAB_MUST_WIDEN says try widening and don't
254   try anything else.  */
255
256enum optab_methods
257{
258  OPTAB_DIRECT,
259  OPTAB_LIB,
260  OPTAB_WIDEN,
261  OPTAB_LIB_WIDEN,
262  OPTAB_MUST_WIDEN
263};
264
265/* Generate code for a simple binary or unary operation.  "Simple" in
266   this case means "can be unambiguously described by a (mode, code)
267   pair and mapped to a single optab."  */
268extern rtx expand_simple_binop PARAMS ((enum machine_mode, enum rtx_code, rtx,
269					rtx, rtx, int, enum optab_methods));
270extern rtx expand_simple_unop PARAMS ((enum machine_mode, enum rtx_code,
271				       rtx, rtx, int));
272
273/* Report whether the machine description contains an insn which can
274   perform the operation described by CODE and MODE.  */
275extern int have_insn_for PARAMS ((enum rtx_code, enum machine_mode));
276
277/* Emit code to make a call to a constant function or a library call.  */
278extern void emit_libcall_block PARAMS ((rtx, rtx, rtx, rtx));
279
280/* Create but don't emit one rtl instruction to perform certain operations.
281   Modes must match; operands must meet the operation's predicates.
282   Likewise for subtraction and for just copying.
283   These do not call protect_from_queue; caller must do so.  */
284extern rtx gen_add2_insn PARAMS ((rtx, rtx));
285extern rtx gen_add3_insn PARAMS ((rtx, rtx, rtx));
286extern rtx gen_sub2_insn PARAMS ((rtx, rtx));
287extern rtx gen_sub3_insn PARAMS ((rtx, rtx, rtx));
288extern rtx gen_move_insn PARAMS ((rtx, rtx));
289extern int have_add2_insn PARAMS ((rtx, rtx));
290extern int have_sub2_insn PARAMS ((rtx, rtx));
291
292/* Emit a pair of rtl insns to compare two rtx's and to jump
293   to a label if the comparison is true.  */
294extern void emit_cmp_and_jump_insns PARAMS ((rtx, rtx, enum rtx_code, rtx,
295					     enum machine_mode, int, rtx));
296
297/* Generate code to indirectly jump to a location given in the rtx LOC.  */
298extern void emit_indirect_jump PARAMS ((rtx));
299
300#ifdef HAVE_conditional_move
301/* Emit a conditional move operation.  */
302rtx emit_conditional_move PARAMS ((rtx, enum rtx_code, rtx, rtx,
303				   enum machine_mode, rtx, rtx,
304				   enum machine_mode, int));
305
306/* Return non-zero if the conditional move is supported.  */
307int can_conditionally_move_p PARAMS ((enum machine_mode mode));
308
309#endif
310
311
312/* Functions from expmed.c:  */
313
314/* Arguments MODE, RTX: return an rtx for the negation of that value.
315   May emit insns.  */
316extern rtx negate_rtx PARAMS ((enum machine_mode, rtx));
317
318/* Expand a logical AND operation.  */
319extern rtx expand_and PARAMS ((enum machine_mode, rtx, rtx, rtx));
320
321/* Emit a store-flag operation.  */
322extern rtx emit_store_flag PARAMS ((rtx, enum rtx_code, rtx, rtx,
323				    enum machine_mode, int, int));
324
325/* Like emit_store_flag, but always succeeds.  */
326extern rtx emit_store_flag_force PARAMS ((rtx, enum rtx_code, rtx, rtx,
327					  enum machine_mode, int, int));
328
329/* Functions from loop.c:  */
330
331/* Given an insn and condition, return a canonical description of
332   the test being made.  */
333extern rtx canonicalize_condition PARAMS ((rtx, rtx, int, rtx *, rtx));
334
335/* Given a JUMP_INSN, return a canonical description of the test
336   being made.  */
337extern rtx get_condition PARAMS ((rtx, rtx *));
338
339/* Generate a conditional trap instruction.  */
340extern rtx gen_cond_trap PARAMS ((enum rtx_code, rtx, rtx, rtx));
341
342/* Functions from builtins.c:  */
343extern rtx expand_builtin PARAMS ((tree, rtx, rtx, enum machine_mode, int));
344extern void std_expand_builtin_va_start PARAMS ((int, tree, rtx));
345extern rtx std_expand_builtin_va_arg PARAMS ((tree, tree));
346extern rtx expand_builtin_va_arg PARAMS ((tree, tree));
347extern void default_init_builtins PARAMS ((void));
348extern rtx default_expand_builtin PARAMS ((tree, rtx, rtx,
349					   enum machine_mode, int));
350extern void expand_builtin_setjmp_setup PARAMS ((rtx, rtx));
351extern void expand_builtin_setjmp_receiver PARAMS ((rtx));
352extern void expand_builtin_longjmp PARAMS ((rtx, rtx));
353extern rtx expand_builtin_saveregs PARAMS ((void));
354extern void expand_builtin_trap PARAMS ((void));
355extern HOST_WIDE_INT get_varargs_alias_set PARAMS ((void));
356extern HOST_WIDE_INT get_frame_alias_set PARAMS ((void));
357extern void record_base_value		PARAMS ((unsigned int, rtx, int));
358extern void record_alias_subset         PARAMS ((HOST_WIDE_INT,
359						 HOST_WIDE_INT));
360extern HOST_WIDE_INT new_alias_set		PARAMS ((void));
361extern int can_address_p		PARAMS ((tree));
362
363/* Functions from expr.c:  */
364
365/* This is run once per compilation to set up which modes can be used
366   directly in memory and to initialize the block move optab.  */
367extern void init_expr_once PARAMS ((void));
368
369/* This is run at the start of compiling a function.  */
370extern void init_expr PARAMS ((void));
371
372/* This function is run once to initialize stor-layout.c.  */
373
374extern void init_stor_layout_once PARAMS ((void));
375
376/* This is run at the end of compiling a function.  */
377extern void finish_expr_for_function PARAMS ((void));
378
379/* Use protect_from_queue to convert a QUEUED expression
380   into something that you can put immediately into an instruction.  */
381extern rtx protect_from_queue PARAMS ((rtx, int));
382
383/* Perform all the pending incrementations.  */
384extern void emit_queue PARAMS ((void));
385
386/* Tell if something has a queued subexpression.  */
387extern int queued_subexp_p PARAMS ((rtx));
388
389/* Emit some rtl insns to move data between rtx's, converting machine modes.
390   Both modes must be floating or both fixed.  */
391extern void convert_move PARAMS ((rtx, rtx, int));
392
393/* Convert an rtx to specified machine mode and return the result.  */
394extern rtx convert_to_mode PARAMS ((enum machine_mode, rtx, int));
395
396/* Convert an rtx to MODE from OLDMODE and return the result.  */
397extern rtx convert_modes PARAMS ((enum machine_mode, enum machine_mode,
398				  rtx, int));
399
400/* Emit code to move a block Y to a block X.  */
401extern rtx emit_block_move PARAMS ((rtx, rtx, rtx));
402
403/* Copy all or part of a value X into registers starting at REGNO.
404   The number of registers to be filled is NREGS.  */
405extern void move_block_to_reg PARAMS ((int, rtx, int, enum machine_mode));
406
407/* Copy all or part of a BLKmode value X out of registers starting at REGNO.
408   The number of registers to be filled is NREGS.  */
409extern void move_block_from_reg PARAMS ((int, rtx, int, int));
410
411/* Load a BLKmode value into non-consecutive registers represented by a
412   PARALLEL.  */
413extern void emit_group_load PARAMS ((rtx, rtx, int));
414
415/* Store a BLKmode value from non-consecutive registers represented by a
416   PARALLEL.  */
417extern void emit_group_store PARAMS ((rtx, rtx, int));
418
419#ifdef TREE_CODE
420/* Copy BLKmode object from a set of registers.  */
421extern rtx copy_blkmode_from_reg PARAMS ((rtx,rtx,tree));
422#endif
423
424/* Mark REG as holding a parameter for the next CALL_INSN.  */
425extern void use_reg PARAMS ((rtx *, rtx));
426
427/* Mark NREGS consecutive regs, starting at REGNO, as holding parameters
428   for the next CALL_INSN.  */
429extern void use_regs PARAMS ((rtx *, int, int));
430
431/* Mark a PARALLEL as holding a parameter for the next CALL_INSN.  */
432extern void use_group_regs PARAMS ((rtx *, rtx));
433
434/* Write zeros through the storage of OBJECT.
435   If OBJECT has BLKmode, SIZE is its length in bytes.  */
436extern rtx clear_storage PARAMS ((rtx, rtx));
437
438/* Return non-zero if it is desirable to store LEN bytes generated by
439   CONSTFUN with several move instructions by store_by_pieces
440   function.  CONSTFUNDATA is a pointer which will be passed as argument
441   in every CONSTFUN call.
442   ALIGN is maximum alignment we can assume.  */
443extern int can_store_by_pieces PARAMS ((unsigned HOST_WIDE_INT,
444					rtx (*) (PTR, HOST_WIDE_INT,
445						 enum machine_mode),
446					PTR, unsigned int));
447
448/* Generate several move instructions to store LEN bytes generated by
449   CONSTFUN to block TO.  (A MEM rtx with BLKmode).  CONSTFUNDATA is a
450   pointer which will be passed as argument in every CONSTFUN call.
451   ALIGN is maximum alignment we can assume.  */
452extern void store_by_pieces PARAMS ((rtx, unsigned HOST_WIDE_INT,
453				     rtx (*) (PTR, HOST_WIDE_INT,
454					      enum machine_mode),
455				     PTR, unsigned int));
456
457/* Emit insns to set X from Y.  */
458extern rtx emit_move_insn PARAMS ((rtx, rtx));
459
460/* Emit insns to set X from Y, with no frills.  */
461extern rtx emit_move_insn_1 PARAMS ((rtx, rtx));
462
463/* Push a block of length SIZE (perhaps variable)
464   and return an rtx to address the beginning of the block.  */
465extern rtx push_block PARAMS ((rtx, int, int));
466
467#ifdef TREE_CODE
468/* Generate code to push something onto the stack, given its mode and type.  */
469extern void emit_push_insn PARAMS ((rtx, enum machine_mode, tree, rtx,
470				    unsigned int, int, rtx, int, rtx, rtx,
471				    int, rtx));
472
473/* Expand an assignment that stores the value of FROM into TO.  */
474extern rtx expand_assignment PARAMS ((tree, tree, int, int));
475
476/* Generate code for computing expression EXP,
477   and storing the value into TARGET.
478   If SUGGEST_REG is nonzero, copy the value through a register
479   and return that register, if that is possible.  */
480extern rtx store_expr PARAMS ((tree, rtx, int));
481#endif
482
483/* Given an rtx that may include add and multiply operations,
484   generate them as insns and return a pseudo-reg containing the value.
485   Useful after calling expand_expr with 1 as sum_ok.  */
486extern rtx force_operand PARAMS ((rtx, rtx));
487
488/* Return an object on the placeholder list that matches EXP, a
489   PLACEHOLDER_EXPR.  An object "matches" if it is of the type of the
490   PLACEHOLDER_EXPR or a pointer type to it.  For further information, see
491   tree.def.  If no such object is found, abort.  If PLIST is nonzero, it is
492   a location which initially points to a starting location in the
493   placeholder list (zero means start of the list) and where a pointer into
494   the placeholder list at which the object is found is placed.  */
495extern tree find_placeholder PARAMS ((tree, tree *));
496
497/* Generate code for computing expression EXP.
498   An rtx for the computed value is returned.  The value is never null.
499   In the case of a void EXP, const0_rtx is returned.  */
500extern rtx expand_expr PARAMS ((tree, rtx, enum machine_mode,
501				enum expand_modifier));
502
503/* At the start of a function, record that we have no previously-pushed
504   arguments waiting to be popped.  */
505extern void init_pending_stack_adjust PARAMS ((void));
506
507/* When exiting from function, if safe, clear out any pending stack adjust
508   so the adjustment won't get done.  */
509extern void clear_pending_stack_adjust PARAMS ((void));
510
511/* Pop any previously-pushed arguments that have not been popped yet.  */
512extern void do_pending_stack_adjust PARAMS ((void));
513
514#ifdef TREE_CODE
515/* Return the tree node and offset if a given argument corresponds to
516   a string constant.  */
517extern tree string_constant PARAMS ((tree, tree *));
518
519/* Generate code to evaluate EXP and jump to LABEL if the value is zero.  */
520extern void jumpifnot PARAMS ((tree, rtx));
521
522/* Generate code to evaluate EXP and jump to LABEL if the value is nonzero.  */
523extern void jumpif PARAMS ((tree, rtx));
524
525/* Generate code to evaluate EXP and jump to IF_FALSE_LABEL if
526   the result is zero, or IF_TRUE_LABEL if the result is one.  */
527extern void do_jump PARAMS ((tree, rtx, rtx));
528#endif
529
530/* Generate rtl to compare two rtx's, will call emit_cmp_insn.  */
531extern rtx compare_from_rtx PARAMS ((rtx, rtx, enum rtx_code, int,
532				     enum machine_mode, rtx));
533extern void do_compare_rtx_and_jump PARAMS ((rtx, rtx, enum rtx_code, int,
534					     enum machine_mode, rtx,
535					     rtx, rtx));
536
537/* Two different ways of generating switch statements.  */
538extern int try_casesi    PARAMS ((tree, tree, tree, tree, rtx, rtx));
539extern int try_tablejump PARAMS ((tree, tree, tree, tree, rtx, rtx));
540
541/* Smallest number of adjacent cases before we use a jump table.
542   XXX Should be a target hook.  */
543extern unsigned int case_values_threshold PARAMS ((void));
544
545
546#ifdef TREE_CODE
547/* rtl.h and tree.h were included.  */
548/* Return an rtx for the size in bytes of the value of an expr.  */
549extern rtx expr_size PARAMS ((tree));
550
551extern rtx lookup_static_chain PARAMS ((tree));
552
553/* Convert a stack slot address ADDR valid in function FNDECL
554   into an address valid in this function (using a static chain).  */
555extern rtx fix_lexical_addr PARAMS ((rtx, tree));
556
557/* Return the address of the trampoline for entering nested fn FUNCTION.  */
558extern rtx trampoline_address PARAMS ((tree));
559
560/* Return an rtx that refers to the value returned by a function
561   in its original home.  This becomes invalid if any more code is emitted.  */
562extern rtx hard_function_value PARAMS ((tree, tree, int));
563
564extern rtx prepare_call_address	PARAMS ((rtx, tree, rtx *, int, int));
565
566extern rtx expand_call PARAMS ((tree, rtx, int));
567
568extern rtx expand_shift PARAMS ((enum tree_code, enum machine_mode, rtx, tree,
569				 rtx, int));
570extern rtx expand_divmod PARAMS ((int, enum tree_code, enum machine_mode, rtx,
571				  rtx, rtx, int));
572extern void locate_and_pad_parm PARAMS ((enum machine_mode, tree, int, tree,
573					 struct args_size *,
574					 struct args_size *,
575					 struct args_size *,
576					 struct args_size *));
577extern rtx expand_inline_function PARAMS ((tree, tree, rtx, int, tree, rtx));
578
579/* Return the CODE_LABEL rtx for a LABEL_DECL, creating it if necessary.  */
580extern rtx label_rtx PARAMS ((tree));
581#endif
582
583/* Indicate how an input argument register was promoted.  */
584extern rtx promoted_input_arg PARAMS ((unsigned int, enum machine_mode *,
585				       int *));
586
587/* Return an rtx like arg but sans any constant terms.
588   Returns the original rtx if it has no constant terms.
589   The constant terms are added and stored via a second arg.  */
590extern rtx eliminate_constant_term PARAMS ((rtx, rtx *));
591
592/* Convert arg to a valid memory address for specified machine mode,
593   by emitting insns to perform arithmetic if nec.  */
594extern rtx memory_address PARAMS ((enum machine_mode, rtx));
595
596/* Like `memory_address' but pretent `flag_force_addr' is 0.  */
597extern rtx memory_address_noforce PARAMS ((enum machine_mode, rtx));
598
599/* Set the alias set of MEM to SET.  */
600extern void set_mem_alias_set PARAMS ((rtx, HOST_WIDE_INT));
601
602/* Set the alignment of MEM to ALIGN bits.  */
603extern void set_mem_align PARAMS ((rtx, unsigned int));
604
605/* Set the expr for MEM to EXPR.  */
606extern void set_mem_expr PARAMS ((rtx, tree));
607
608/* Set the offset for MEM to OFFSET.  */
609extern void set_mem_offset PARAMS ((rtx, rtx));
610
611/* Return a memory reference like MEMREF, but with its mode changed
612   to MODE and its address changed to ADDR.
613   (VOIDmode means don't change the mode.
614   NULL for ADDR means don't change the address.)  */
615extern rtx change_address PARAMS ((rtx, enum machine_mode, rtx));
616
617/* Return a memory reference like MEMREF, but with its mode changed
618   to MODE and its address offset by OFFSET bytes.  */
619#define adjust_address(MEMREF, MODE, OFFSET) \
620  adjust_address_1 (MEMREF, MODE, OFFSET, 1, 1)
621
622/* Likewise, but the reference is not required to be valid.  */
623#define adjust_address_nv(MEMREF, MODE, OFFSET) \
624  adjust_address_1 (MEMREF, MODE, OFFSET, 0, 1)
625
626/* Return a memory reference like MEMREF, but with its mode changed
627   to MODE and its address changed to ADDR, which is assumed to be
628   increased by OFFSET bytes from MEMREF.  */
629#define adjust_automodify_address(MEMREF, MODE, ADDR, OFFSET) \
630  adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 1)
631
632/* Likewise, but the reference is not required to be valid.  */
633#define adjust_automodify_address_nv(MEMREF, MODE, ADDR, OFFSET) \
634  adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 0)
635
636extern rtx adjust_address_1 PARAMS ((rtx, enum machine_mode, HOST_WIDE_INT,
637				     int, int));
638extern rtx adjust_automodify_address_1 PARAMS ((rtx, enum machine_mode,
639						rtx, HOST_WIDE_INT, int));
640
641/* Return a memory reference like MEMREF, but whose address is changed by
642   adding OFFSET, an RTX, to it.  POW2 is the highest power of two factor
643   known to be in OFFSET (possibly 1).  */
644extern rtx offset_address PARAMS ((rtx, rtx, HOST_WIDE_INT));
645
646/* Return a memory reference like MEMREF, but with its address changed to
647   ADDR.  The caller is asserting that the actual piece of memory pointed
648   to is the same, just the form of the address is being changed, such as
649   by putting something into a register.  */
650extern rtx replace_equiv_address PARAMS ((rtx, rtx));
651
652/* Likewise, but the reference is not required to be valid.  */
653extern rtx replace_equiv_address_nv PARAMS ((rtx, rtx));
654
655/* Return a memory reference like MEMREF, but with its mode widened to
656   MODE and adjusted by OFFSET.  */
657extern rtx widen_memory_access PARAMS ((rtx, enum machine_mode, HOST_WIDE_INT));
658
659/* Return a memory reference like MEMREF, but which is known to have a
660   valid address.  */
661extern rtx validize_mem PARAMS ((rtx));
662
663#ifdef TREE_CODE
664/* Given REF, either a MEM or a REG, and T, either the type of X or
665   the expression corresponding to REF, set RTX_UNCHANGING_P if
666   appropriate.  */
667extern void maybe_set_unchanging PARAMS ((rtx, tree));
668
669/* Given REF, a MEM, and T, either the type of X or the expression
670   corresponding to REF, set the memory attributes.  OBJECTP is nonzero
671   if we are making a new object of this type.  */
672extern void set_mem_attributes PARAMS ((rtx, tree, int));
673#endif
674
675/* Assemble the static constant template for function entry trampolines.  */
676extern rtx assemble_trampoline_template PARAMS ((void));
677
678/* Given rtx, return new rtx whose address won't be affected by
679   any side effects.  It has been copied to a new temporary reg.  */
680extern rtx stabilize PARAMS ((rtx));
681
682/* Given an rtx, copy all regs it refers to into new temps
683   and return a modified copy that refers to the new temps.  */
684extern rtx copy_all_regs PARAMS ((rtx));
685
686/* Copy given rtx to a new temp reg and return that.  */
687extern rtx copy_to_reg PARAMS ((rtx));
688
689/* Like copy_to_reg but always make the reg Pmode.  */
690extern rtx copy_addr_to_reg PARAMS ((rtx));
691
692/* Like copy_to_reg but always make the reg the specified mode MODE.  */
693extern rtx copy_to_mode_reg PARAMS ((enum machine_mode, rtx));
694
695/* Copy given rtx to given temp reg and return that.  */
696extern rtx copy_to_suggested_reg PARAMS ((rtx, rtx, enum machine_mode));
697
698/* Copy a value to a register if it isn't already a register.
699   Args are mode (in case value is a constant) and the value.  */
700extern rtx force_reg PARAMS ((enum machine_mode, rtx));
701
702/* Return given rtx, copied into a new temp reg if it was in memory.  */
703extern rtx force_not_mem PARAMS ((rtx));
704
705#ifdef TREE_CODE
706/* Return mode and signedness to use when object is promoted.  */
707extern enum machine_mode promote_mode PARAMS ((tree, enum machine_mode,
708					       int *, int));
709#endif
710
711/* Remove some bytes from the stack.  An rtx says how many.  */
712extern void adjust_stack PARAMS ((rtx));
713
714/* Add some bytes to the stack.  An rtx says how many.  */
715extern void anti_adjust_stack PARAMS ((rtx));
716
717/* This enum is used for the following two functions.  */
718enum save_level {SAVE_BLOCK, SAVE_FUNCTION, SAVE_NONLOCAL};
719
720/* Save the stack pointer at the specified level.  */
721extern void emit_stack_save PARAMS ((enum save_level, rtx *, rtx));
722
723/* Restore the stack pointer from a save area of the specified level.  */
724extern void emit_stack_restore PARAMS ((enum save_level, rtx, rtx));
725
726/* Allocate some space on the stack dynamically and return its address.  An rtx
727   says how many bytes.  */
728extern rtx allocate_dynamic_stack_space PARAMS ((rtx, rtx, int));
729
730/* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
731   FIRST is a constant and size is a Pmode RTX.  These are offsets from the
732   current stack pointer.  STACK_GROWS_DOWNWARD says whether to add or
733   subtract from the stack.  If SIZE is constant, this is done
734   with a fixed number of probes.  Otherwise, we must make a loop.  */
735extern void probe_stack_range PARAMS ((HOST_WIDE_INT, rtx));
736
737/* Return an rtx that refers to the value returned by a library call
738   in its original home.  This becomes invalid if any more code is emitted.  */
739extern rtx hard_libcall_value PARAMS ((enum machine_mode));
740
741/* Given an rtx, return an rtx for a value rounded up to a multiple
742   of STACK_BOUNDARY / BITS_PER_UNIT.  */
743extern rtx round_push PARAMS ((rtx));
744
745/* Return the mode desired by operand N of a particular bitfield
746   insert/extract insn, or MAX_MACHINE_MODE if no such insn is
747   available.  */
748
749enum extraction_pattern { EP_insv, EP_extv, EP_extzv };
750extern enum machine_mode
751mode_for_extraction PARAMS ((enum extraction_pattern, int));
752
753extern rtx store_bit_field PARAMS ((rtx, unsigned HOST_WIDE_INT,
754				    unsigned HOST_WIDE_INT,
755				    enum machine_mode, rtx, HOST_WIDE_INT));
756extern rtx extract_bit_field PARAMS ((rtx, unsigned HOST_WIDE_INT,
757				      unsigned HOST_WIDE_INT, int, rtx,
758				      enum machine_mode, enum machine_mode,
759				      HOST_WIDE_INT));
760extern rtx expand_mult PARAMS ((enum machine_mode, rtx, rtx, rtx, int));
761extern rtx expand_mult_add PARAMS ((rtx, rtx, rtx, rtx,enum machine_mode, int));
762extern rtx expand_mult_highpart_adjust PARAMS ((enum machine_mode, rtx, rtx, rtx, rtx, int));
763
764extern rtx assemble_static_space PARAMS ((int));
765
766/* Hook called by expand_expr for language-specific tree codes.
767   It is up to the language front end to install a hook
768   if it has any such codes that expand_expr needs to know about.  */
769extern rtx (*lang_expand_expr) PARAMS ((union tree_node *, rtx,
770					enum machine_mode,
771					enum expand_modifier modifier));
772
773extern int safe_from_p PARAMS ((rtx, tree, int));
774
775/* Call this once to initialize the contents of the optabs
776   appropriately for the current target machine.  */
777extern void init_optabs				PARAMS ((void));
778extern void init_all_optabs			PARAMS ((void));
779
780/* Call this to initialize an optab function entry.  */
781extern rtx init_one_libfunc			PARAMS ((const char *));
782
783extern void do_jump_by_parts_equality_rtx	PARAMS ((rtx, rtx, rtx));
784extern void do_jump_by_parts_greater_rtx	PARAMS ((enum machine_mode,
785							 int, rtx, rtx, rtx,
786							 rtx));
787
788#ifdef TREE_CODE   /* Don't lose if tree.h not included.  */
789extern void mark_seen_cases			PARAMS ((tree, unsigned char *,
790							 HOST_WIDE_INT, int));
791#endif
792