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1/* Definitions for code generation pass of GNU compiler.
2 Copyright (C) 1987, 1991 Free Software Foundation, Inc.
3
4This file is part of GNU CC.
5
6GNU CC is free software; you can redistribute it and/or modify
7it under the terms of the GNU General Public License as published by
8the Free Software Foundation; either version 2, or (at your option)
9any later version.
10
11GNU CC is distributed in the hope that it will be useful,
12but WITHOUT ANY WARRANTY; without even the implied warranty of
13MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14GNU General Public License for more details.
15
16You should have received a copy of the GNU General Public License
17along with GNU CC; see the file COPYING. If not, write to
18the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
19
20
21#ifndef __STDC__
22#ifndef const
23#define const
24#endif
25#endif
26
27/* The default branch cost is 1. */
28#ifndef BRANCH_COST
29#define BRANCH_COST 1
30#endif
31
32/* Macros to access the slots of a QUEUED rtx.
33 Here rather than in rtl.h because only the expansion pass
34 should ever encounter a QUEUED. */
35
36/* The variable for which an increment is queued. */
37#define QUEUED_VAR(P) XEXP (P, 0)
38/* If the increment has been emitted, this is the insn
39 that does the increment. It is zero before the increment is emitted. */
40#define QUEUED_INSN(P) XEXP (P, 1)
41/* If a pre-increment copy has been generated, this is the copy
42 (it is a temporary reg). Zero if no copy made yet. */
43#define QUEUED_COPY(P) XEXP (P, 2)
44/* This is the body to use for the insn to do the increment.
45 It is used to emit the increment. */
46#define QUEUED_BODY(P) XEXP (P, 3)
47/* Next QUEUED in the queue. */
48#define QUEUED_NEXT(P) XEXP (P, 4)
49
50/* This is the 4th arg to `expand_expr'.
51 EXPAND_SUM means it is ok to return a PLUS rtx or MULT rtx.
52 EXPAND_INITIALIZER is similar but also record any labels on forced_labels.
53 EXPAND_CONST_ADDRESS means it is ok to return a MEM whose address
54 is a constant that is not a legitimate address. */
55enum expand_modifier {EXPAND_NORMAL, EXPAND_SUM,
56 EXPAND_CONST_ADDRESS, EXPAND_INITIALIZER};
57
58/* List of labels that must never be deleted. */
59extern rtx forced_labels;
60
61/* List (chain of EXPR_LISTs) of pseudo-regs of SAVE_EXPRs.
62 So we can mark them all live at the end of the function, if stupid. */
63extern rtx save_expr_regs;
64
65extern int current_function_calls_alloca;
66extern int current_function_outgoing_args_size;
67
68/* This is the offset from the arg pointer to the place where the first
69 anonymous arg can be found, if there is one. */
70extern rtx current_function_arg_offset_rtx;
71
72/* This is nonzero if the current function uses the constant pool. */
73extern int current_function_uses_const_pool;
74
75/* This is nonzero if the current function uses pic_offset_table_rtx. */
76extern int current_function_uses_pic_offset_table;
77
78/* The arg pointer hard register, or the pseudo into which it was copied. */
79extern rtx current_function_internal_arg_pointer;
80
81/* Nonzero means stack pops must not be deferred, and deferred stack
82 pops must not be output. It is nonzero inside a function call,
83 inside a conditional expression, inside a statement expression,
84 and in other cases as well. */
85extern int inhibit_defer_pop;
86
87/* Number of function calls seen so far in current function. */
88
89extern int function_call_count;
90
91/* RTX for stack slot that holds the current handler for nonlocal gotos.
92 Zero when function does not have nonlocal labels. */
93
94extern rtx nonlocal_goto_handler_slot;
95
96/* RTX for stack slot that holds the stack pointer value to restore
97 for a nonlocal goto.
98 Zero when function does not have nonlocal labels. */
99
100extern rtx nonlocal_goto_stack_level;
101
102/* List (chain of TREE_LIST) of LABEL_DECLs for all nonlocal labels
103 (labels to which there can be nonlocal gotos from nested functions)
104 in this function. */
105
106#ifdef TREE_CODE /* Don't lose if tree.h not included. */
107extern tree nonlocal_labels;
108#endif
109
110#define NO_DEFER_POP (inhibit_defer_pop += 1)
111#define OK_DEFER_POP (inhibit_defer_pop -= 1)
112
113/* Number of units that we should eventually pop off the stack.
114 These are the arguments to function calls that have already returned. */
115extern int pending_stack_adjust;
116
117/* A list of all cleanups which belong to the arguments of
118 function calls being expanded by expand_call. */
119#ifdef TREE_CODE /* Don't lose if tree.h not included. */
120extern tree cleanups_this_call;
121#endif
122\f
123#ifdef TREE_CODE /* Don't lose if tree.h not included. */
124/* Structure to record the size of a sequence of arguments
125 as the sum of a tree-expression and a constant. */
126
127struct args_size
128{
129 int constant;
130 tree var;
131};
132#endif
133
134/* Add the value of the tree INC to the `struct args_size' TO. */
135
136#define ADD_PARM_SIZE(TO, INC) \
137{ tree inc = (INC); \
138 if (TREE_CODE (inc) == INTEGER_CST) \
139 (TO).constant += TREE_INT_CST_LOW (inc); \
140 else if ((TO).var == 0) \
141 (TO).var = inc; \
142 else \
143 (TO).var = size_binop (PLUS_EXPR, (TO).var, inc); }
144
145#define SUB_PARM_SIZE(TO, DEC) \
146{ tree dec = (DEC); \
147 if (TREE_CODE (dec) == INTEGER_CST) \
148 (TO).constant -= TREE_INT_CST_LOW (dec); \
149 else if ((TO).var == 0) \
150 (TO).var = size_binop (MINUS_EXPR, integer_zero_node, dec); \
151 else \
152 (TO).var = size_binop (MINUS_EXPR, (TO).var, dec); }
153
154/* Convert the implicit sum in a `struct args_size' into an rtx. */
155#define ARGS_SIZE_RTX(SIZE) \
156((SIZE).var == 0 ? gen_rtx (CONST_INT, VOIDmode, (SIZE).constant) \
157 : expand_expr (size_binop (PLUS_EXPR, (SIZE).var, \
158 size_int ((SIZE).constant)), \
159 0, VOIDmode, 0))
160
161/* Convert the implicit sum in a `struct args_size' into a tree. */
162#define ARGS_SIZE_TREE(SIZE) \
163((SIZE).var == 0 ? size_int ((SIZE).constant) \
164 : size_binop (PLUS_EXPR, (SIZE).var, size_int ((SIZE).constant)))
165
166/* Supply a default definition for FUNCTION_ARG_PADDING:
167 usually pad upward, but pad short, non-BLKmode args downward on
168 big-endian machines. */
169
170enum direction {none, upward, downward}; /* Value has this type. */
171
172#ifndef FUNCTION_ARG_PADDING
173#if BYTES_BIG_ENDIAN
174#define FUNCTION_ARG_PADDING(MODE, TYPE) \
175 (((MODE) == BLKmode \
176 ? ((TYPE) && TREE_CODE (TYPE_SIZE (TYPE)) == INTEGER_CST \
177 && int_size_in_bytes (TYPE) < PARM_BOUNDARY / BITS_PER_UNIT) \
178 : GET_MODE_BITSIZE (MODE) < PARM_BOUNDARY) \
179 ? downward : upward)
180#else
181#define FUNCTION_ARG_PADDING(MODE, TYPE) upward
182#endif
183#endif
184
185/* Supply a default definition for FUNCTION_ARG_BOUNDARY. Normally, we let
186 FUNCTION_ARG_PADDING, which also pads the length, handle any needed
187 alignment. */
188
189#ifndef FUNCTION_ARG_BOUNDARY
190#define FUNCTION_ARG_BOUNDARY(MODE, TYPE) PARM_BOUNDARY
191#endif
192
193/* Nonzero if we do not know how to pass TYPE solely in registers.
194 We cannot do so in the following cases:
195
196 - if the type has variable size
197 - if the type is marked as addressable (it is required to be constructed
198 into the stack)
199 - if the padding and mode of the type is such that a copy into a register
200 would put it into the wrong part of the register
201 - when STRICT_ALIGNMENT and the type is BLKmode and is is not
202 aligned to a boundary corresponding to what can be loaded into a
203 register. */
204
205#define MUST_PASS_IN_STACK_BAD_ALIGN(MODE,TYPE) \
206 (STRICT_ALIGNMENT && MODE == BLKmode \
207 && TYPE_ALIGN (TYPE) < (BIGGEST_ALIGNMENT < BITS_PER_WORD \
208 ? BIGGEST_ALIGNMENT : BITS_PER_WORD))
209
210/* Which padding can't be supported depends on the byte endianness. */
211
212/* A value in a register is implicitly padded at the most significant end.
213 On a big-endian machine, that is the lower end in memory.
214 So a value padded in memory at the upper end can't go in a register.
215 For a little-endian machine, the reverse is true. */
216
217#if BYTES_BIG_ENDIAN
218#define MUST_PASS_IN_STACK_BAD_PADDING upward
219#else
220#define MUST_PASS_IN_STACK_BAD_PADDING downward
221#endif
222
223#define MUST_PASS_IN_STACK(MODE,TYPE) \
224 ((TYPE) != 0 \
225 && (TREE_CODE (TYPE_SIZE (TYPE)) != INTEGER_CST \
226 || TREE_ADDRESSABLE (TYPE) \
227 || ((MODE) == BLKmode \
228 && (FUNCTION_ARG_PADDING (MODE, TYPE) \
229 == MUST_PASS_IN_STACK_BAD_PADDING)) \
230 || MUST_PASS_IN_STACK_BAD_ALIGN (MODE, TYPE)))
231
232/* Nonzero if type TYPE should be returned in memory
233 (even though its mode is not BLKmode).
234 Most machines can use the following default definition. */
235
236#ifndef RETURN_IN_MEMORY
237#define RETURN_IN_MEMORY(TYPE) 0
238#endif
239\f
240/* Optabs are tables saying how to generate insn bodies
241 for various machine modes and numbers of operands.
242 Each optab applies to one operation.
243 For example, add_optab applies to addition.
244
245 The insn_code slot is the enum insn_code that says how to
246 generate an insn for this operation on a particular machine mode.
247 It is CODE_FOR_nothing if there is no such insn on the target machine.
248
249 The `lib_call' slot is the name of the library function that
250 can be used to perform the operation.
251
252 A few optabs, such as move_optab and cmp_optab, are used
253 by special code. */
254
255/* Everything that uses expr.h needs to define enum insn_code
256 but we don't list it in the Makefile dependencies just for that. */
257#include "insn-codes.h"
258
259typedef struct optab
260{
261 enum rtx_code code;
262 struct {
263 enum insn_code insn_code;
264 rtx libfunc;
265 } handlers [NUM_MACHINE_MODES];
266} * optab;
267
268/* Given an enum insn_code, access the function to construct
269 the body of that kind of insn. */
270#ifdef FUNCTION_CONVERSION_BUG
271/* Some compilers fail to convert a function properly to a
272 pointer-to-function when used as an argument.
273 So produce the pointer-to-function directly.
274 Luckily, these compilers seem to work properly when you
275 call the pointer-to-function. */
276#define GEN_FCN(CODE) (insn_gen_function[(int) (CODE)])
277#else
278#define GEN_FCN(CODE) (*insn_gen_function[(int) (CODE)])
279#endif
280
281extern rtx (*const insn_gen_function[]) ();
282
283extern optab add_optab;
284extern optab sub_optab;
8cbe2917 285extern optab smul_optab; /* Signed and floating-point multiply */
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286extern optab smul_widen_optab; /* Signed multiply with result
287 one machine mode wider than args */
288extern optab umul_widen_optab;
289extern optab sdiv_optab; /* Signed divide */
290extern optab sdivmod_optab; /* Signed divide-and-remainder in one */
291extern optab udiv_optab;
292extern optab udivmod_optab;
293extern optab smod_optab; /* Signed remainder */
294extern optab umod_optab;
295extern optab flodiv_optab; /* Optab for floating divide. */
296extern optab ftrunc_optab; /* Convert float to integer in float fmt */
297extern optab and_optab; /* Logical and */
298extern optab ior_optab; /* Logical or */
299extern optab xor_optab; /* Logical xor */
300extern optab ashl_optab; /* Arithmetic shift left */
301extern optab ashr_optab; /* Arithmetic shift right */
302extern optab lshl_optab; /* Logical shift left */
303extern optab lshr_optab; /* Logical shift right */
304extern optab rotl_optab; /* Rotate left */
305extern optab rotr_optab; /* Rotate right */
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306extern optab smin_optab; /* Signed and floating-point minimum value */
307extern optab smax_optab; /* Signed and floating-point maximum value */
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308extern optab umin_optab; /* Unsigned minimum value */
309extern optab umax_optab; /* Unsigned maximum value */
310
311extern optab mov_optab; /* Move instruction. */
312extern optab movstrict_optab; /* Move, preserving high part of register. */
313
314extern optab cmp_optab; /* Compare insn; two operands. */
315extern optab tst_optab; /* tst insn; compare one operand against 0 */
316
317/* Unary operations */
318extern optab neg_optab; /* Negation */
319extern optab abs_optab; /* Abs value */
320extern optab one_cmpl_optab; /* Bitwise not */
321extern optab ffs_optab; /* Find first bit set */
07fe1625 322extern optab sqrt_optab; /* Square root */
b91c3756 323extern optab strlen_optab; /* String length */
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324
325/* Passed to expand_binop and expand_unop to say which options to try to use
326 if the requested operation can't be open-coded on the requisite mode.
327 Either OPTAB_LIB or OPTAB_LIB_WIDEN says try using a library call.
328 Either OPTAB_WIDEN or OPTAB_LIB_WIDEN says try using a wider mode.
329 OPTAB_MUST_WIDEN says try widening and don't try anything else. */
330
331enum optab_methods
332{
333 OPTAB_DIRECT,
334 OPTAB_LIB,
335 OPTAB_WIDEN,
336 OPTAB_LIB_WIDEN,
337 OPTAB_MUST_WIDEN
338};
339
340/* SYMBOL_REF rtx's for the library functions that are called
341 implicitly and not via optabs. */
342
343extern rtx extendsfdf2_libfunc;
344extern rtx truncdfsf2_libfunc;
345extern rtx memcpy_libfunc;
346extern rtx bcopy_libfunc;
347extern rtx memcmp_libfunc;
348extern rtx bcmp_libfunc;
349extern rtx memset_libfunc;
350extern rtx bzero_libfunc;
351extern rtx eqsf2_libfunc;
352extern rtx nesf2_libfunc;
353extern rtx gtsf2_libfunc;
354extern rtx gesf2_libfunc;
355extern rtx ltsf2_libfunc;
356extern rtx lesf2_libfunc;
357extern rtx eqdf2_libfunc;
358extern rtx nedf2_libfunc;
359extern rtx gtdf2_libfunc;
360extern rtx gedf2_libfunc;
361extern rtx ltdf2_libfunc;
362extern rtx ledf2_libfunc;
363extern rtx floatdisf_libfunc;
364extern rtx floatsisf_libfunc;
365extern rtx floatdidf_libfunc;
366extern rtx floatsidf_libfunc;
367extern rtx fixsfsi_libfunc;
368extern rtx fixsfdi_libfunc;
369extern rtx fixdfsi_libfunc;
370extern rtx fixdfdi_libfunc;
371extern rtx fixunssfsi_libfunc;
372extern rtx fixunssfdi_libfunc;
373extern rtx fixunsdfsi_libfunc;
374extern rtx fixunsdfdi_libfunc;
375\f
376typedef rtx (*rtxfun) ();
377
378/* Indexed by the rtx-code for a conditional (eg. EQ, LT,...)
379 gives the gen_function to make a branch to test that condition. */
380
381extern rtxfun bcc_gen_fctn[NUM_RTX_CODE];
382
383/* Indexed by the rtx-code for a conditional (eg. EQ, LT,...)
384 gives the insn code to make a store-condition insn
385 to test that condition. */
386
387extern enum insn_code setcc_gen_code[NUM_RTX_CODE];
388
389/* Expand a binary operation given optab and rtx operands. */
390extern rtx expand_binop ();
391
392/* Expand a binary operation with both signed and unsigned forms. */
393extern rtx sign_expand_binop ();
394
395/* Expand a unary arithmetic operation given optab rtx operand. */
396extern rtx expand_unop ();
397
398/* Arguments MODE, RTX: return an rtx for the negation of that value.
399 May emit insns. */
400extern rtx negate_rtx ();
401
402/* Expand a logical AND operation. */
403extern rtx expand_and ();
404
405/* Emit a store-flag operation. */
406extern rtx emit_store_flag ();
407
408/* Return the CODE_LABEL rtx for a LABEL_DECL, creating it if necessary. */
409extern rtx label_rtx ();
410
411/* Given a JUMP_INSN, return a description of the test being made. */
412extern rtx get_condition ();
413
414/* Return the INSN_CODE to use for an extend operation. */
415extern enum insn_code can_extend_p ();
416
417/* Initialize the tables that control conversion between fixed and
418 floating values. */
419extern void init_fixtab ();
420extern void init_floattab ();
421
422/* Generate code for a FIX_EXPR. */
423extern void expand_fix ();
424
425/* Generate code for a FLOAT_EXPR. */
426extern void expand_float ();
427
428/* Create but don't emit one rtl instruction to add one rtx into another.
429 Modes must match; operands must meet the operation's predicates.
430 Likewise for subtraction and for just copying.
431 These do not call protect_from_queue; caller must do so. */
432extern rtx gen_add2_insn ();
433extern rtx gen_sub2_insn ();
434extern rtx gen_move_insn ();
435
436/* Emit one rtl instruction to store zero in specified rtx. */
437extern void emit_clr_insn ();
438
439/* Emit one rtl insn to store 1 in specified rtx assuming it contains 0. */
440extern void emit_0_to_1_insn ();
441
442/* Emit one rtl insn to compare two rtx's. */
443extern void emit_cmp_insn ();
444
6dc42e49 445/* Generate rtl to compare two rtx's, will call emit_cmp_insn. */
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446extern rtx compare_from_rtx ();
447
448/* Emit some rtl insns to move data between rtx's, converting machine modes.
449 Both modes must be floating or both fixed. */
450extern void convert_move ();
451
452/* Convert an rtx to specified machine mode and return the result. */
453extern rtx convert_to_mode ();
454
455/* Emit code to push some arguments and call a library routine,
456 storing the value in a specified place. Calling sequence is
457 complicated. */
458extern void emit_library_call ();
459
460/* Given an rtx that may include add and multiply operations,
461 generate them as insns and return a pseudo-reg containing the value.
462 Useful after calling expand_expr with 1 as sum_ok. */
463extern rtx force_operand ();
464
465/* Return an rtx for the size in bytes of the value of an expr. */
466extern rtx expr_size ();
467
468/* Return an rtx for the sum of an rtx and an integer. */
469extern rtx plus_constant ();
470
471extern rtx lookup_static_chain ();
472
473/* Return an rtx like arg but sans any constant terms.
474 Returns the original rtx if it has no constant terms.
475 The constant terms are added and stored via a second arg. */
476extern rtx eliminate_constant_term ();
477
478/* Convert arg to a valid memory address for specified machine mode,
479 by emitting insns to perform arithmetic if nec. */
480extern rtx memory_address ();
481
482/* Like `memory_address' but pretent `flag_force_addr' is 0. */
483extern rtx memory_address_noforce ();
484
485/* Return a memory reference like MEMREF, but with its mode changed
486 to MODE and its address changed to ADDR.
487 (VOIDmode means don't change the mode.
488 NULL for ADDR means don't change the address.) */
489extern rtx change_address ();
490
491/* Return a memory reference like MEMREF, but which is known to have a
492 valid address. */
493
494extern rtx validize_mem ();
495
496/* Convert a stack slot address ADDR valid in function FNDECL
497 into an address valid in this function (using a static chain). */
498extern rtx fix_lexical_addr ();
499
500/* Return the address of the trampoline for entering nested fn FUNCTION. */
501extern rtx trampoline_address ();
502
503/* Assemble the static constant template for function entry trampolines. */
504extern rtx assemble_trampoline_template ();
505
506/* Return 1 if two rtx's are equivalent in structure and elements. */
507extern int rtx_equal_p ();
508
509/* Given rtx, return new rtx whose address won't be affected by
510 any side effects. It has been copied to a new temporary reg. */
511extern rtx stabilize ();
512
513/* Given an rtx, copy all regs it refers to into new temps
514 and return a modified copy that refers to the new temps. */
515extern rtx copy_all_regs ();
516
517/* Copy given rtx to a new temp reg and return that. */
518extern rtx copy_to_reg ();
519
520/* Like copy_to_reg but always make the reg Pmode. */
521extern rtx copy_addr_to_reg ();
522
523/* Like copy_to_reg but always make the reg the specified mode MODE. */
524extern rtx copy_to_mode_reg ();
525
526/* Copy given rtx to given temp reg and return that. */
527extern rtx copy_to_suggested_reg ();
528
529/* Copy a value to a register if it isn't already a register.
530 Args are mode (in case value is a constant) and the value. */
531extern rtx force_reg ();
532
533/* Return given rtx, copied into a new temp reg if it was in memory. */
534extern rtx force_not_mem ();
535
536/* Remove some bytes from the stack. An rtx says how many. */
537extern void adjust_stack ();
538
539/* Add some bytes to the stack. An rtx says how many. */
540extern void anti_adjust_stack ();
541
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542/* This enum is used for the following two functions. */
543enum save_level {SAVE_BLOCK, SAVE_FUNCTION, SAVE_NONLOCAL};
544
545/* Save the stack pointer at the specified level. */
546extern void emit_stack_save ();
547
548/* Restore the stack pointer from a save area of the specified level. */
549extern void emit_stack_restore ();
550
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551/* Allocate some space on the stack dynamically and return its address. An rtx
552 says how many bytes. */
553extern rtx allocate_dynamic_stack_space ();
554
555/* Emit code to copy function value to a new temp reg and return that reg. */
556extern rtx function_value ();
557
558/* Return an rtx that refers to the value returned by a function
559 in its original home. This becomes invalid if any more code is emitted. */
560extern rtx hard_function_value ();
561
562/* Return an rtx that refers to the value returned by a library call
563 in its original home. This becomes invalid if any more code is emitted. */
564extern rtx hard_libcall_value ();
565
566/* Emit code to copy function value to a specified place. */
567extern void copy_function_value ();
568
569/* Given an rtx, return an rtx for a value rounded up to a multiple
570 of STACK_BOUNDARY / BITS_PER_UNIT. */
571extern rtx round_push ();
572
573/* Push a block of length SIZE (perhaps variable)
574 and return an rtx to address the beginning of the block. */
575extern rtx push_block ();
576
577/* Generate code for computing expression EXP,
578 and storing the value into TARGET.
579 If SUGGEST_REG is nonzero, copy the value through a register
580 and return that register, if that is possible. */
581extern rtx store_expr ();
582
583extern rtx prepare_call_address ();
584extern rtx expand_call ();
585extern void emit_call_1 ();
586
587extern void emit_block_move ();
588extern void emit_push_insn ();
589extern void use_regs ();
590extern void move_block_to_reg ();
591
592extern rtx store_bit_field ();
593extern rtx extract_bit_field ();
594extern rtx expand_shift ();
595extern rtx expand_mult ();
596extern rtx expand_divmod ();
597extern rtx expand_mult_add ();
598extern rtx expand_stmt_expr ();
599extern rtx emit_no_conflict_block ();
600extern void emit_libcall_block ();
601
602extern void jumpifnot ();
603extern void jumpif ();
604extern void do_jump ();
605
606extern rtx assemble_static_space ();
607
608extern void locate_and_pad_parm ();
609
610extern rtx expand_inline_function ();
611
612/* Hook called by expand_expr for language-specific tree codes.
613 It is up to the language front end to install a hook
614 if it has any such codes that expand_expr needs to know about. */
615extern rtx (*lang_expand_expr) ();
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