1 /* Definitions for code generation pass of GNU compiler.
2 Copyright (C) 1987, 1991 Free Software Foundation, Inc.
4 This file is part of GNU CC.
6 GNU CC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU CC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU CC; see the file COPYING. If not, write to
18 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
27 /* The default branch cost is 1. */
32 /* The default is that we do not promote the mode of an object. */
34 #define PROMOTE_MODE(MODE,UNSIGNEDP,TYPE)
37 /* Macros to access the slots of a QUEUED rtx.
38 Here rather than in rtl.h because only the expansion pass
39 should ever encounter a QUEUED. */
41 /* The variable for which an increment is queued. */
42 #define QUEUED_VAR(P) XEXP (P, 0)
43 /* If the increment has been emitted, this is the insn
44 that does the increment. It is zero before the increment is emitted. */
45 #define QUEUED_INSN(P) XEXP (P, 1)
46 /* If a pre-increment copy has been generated, this is the copy
47 (it is a temporary reg). Zero if no copy made yet. */
48 #define QUEUED_COPY(P) XEXP (P, 2)
49 /* This is the body to use for the insn to do the increment.
50 It is used to emit the increment. */
51 #define QUEUED_BODY(P) XEXP (P, 3)
52 /* Next QUEUED in the queue. */
53 #define QUEUED_NEXT(P) XEXP (P, 4)
55 /* This is the 4th arg to `expand_expr'.
56 EXPAND_SUM means it is ok to return a PLUS rtx or MULT rtx.
57 EXPAND_INITIALIZER is similar but also record any labels on forced_labels.
58 EXPAND_CONST_ADDRESS means it is ok to return a MEM whose address
59 is a constant that is not a legitimate address. */
60 enum expand_modifier {EXPAND_NORMAL, EXPAND_SUM,
61 EXPAND_CONST_ADDRESS, EXPAND_INITIALIZER};
63 /* List of labels that must never be deleted. */
64 extern rtx forced_labels;
66 /* List (chain of EXPR_LISTs) of pseudo-regs of SAVE_EXPRs.
67 So we can mark them all live at the end of the function, if stupid. */
68 extern rtx save_expr_regs;
70 extern int current_function_calls_alloca;
71 extern int current_function_outgoing_args_size;
73 /* This is the offset from the arg pointer to the place where the first
74 anonymous arg can be found, if there is one. */
75 extern rtx current_function_arg_offset_rtx;
77 /* This is nonzero if the current function uses the constant pool. */
78 extern int current_function_uses_const_pool;
80 /* This is nonzero if the current function uses pic_offset_table_rtx. */
81 extern int current_function_uses_pic_offset_table;
83 /* The arg pointer hard register, or the pseudo into which it was copied. */
84 extern rtx current_function_internal_arg_pointer;
86 /* Nonzero means stack pops must not be deferred, and deferred stack
87 pops must not be output. It is nonzero inside a function call,
88 inside a conditional expression, inside a statement expression,
89 and in other cases as well. */
90 extern int inhibit_defer_pop;
92 /* Number of function calls seen so far in current function. */
94 extern int function_call_count;
96 /* RTX for stack slot that holds the current handler for nonlocal gotos.
97 Zero when function does not have nonlocal labels. */
99 extern rtx nonlocal_goto_handler_slot;
101 /* RTX for stack slot that holds the stack pointer value to restore
103 Zero when function does not have nonlocal labels. */
105 extern rtx nonlocal_goto_stack_level;
107 /* List (chain of TREE_LIST) of LABEL_DECLs for all nonlocal labels
108 (labels to which there can be nonlocal gotos from nested functions)
111 #ifdef TREE_CODE /* Don't lose if tree.h not included. */
112 extern tree nonlocal_labels;
115 #define NO_DEFER_POP (inhibit_defer_pop += 1)
116 #define OK_DEFER_POP (inhibit_defer_pop -= 1)
118 /* Number of units that we should eventually pop off the stack.
119 These are the arguments to function calls that have already returned. */
120 extern int pending_stack_adjust;
122 /* A list of all cleanups which belong to the arguments of
123 function calls being expanded by expand_call. */
124 #ifdef TREE_CODE /* Don't lose if tree.h not included. */
125 extern tree cleanups_this_call;
128 #ifdef TREE_CODE /* Don't lose if tree.h not included. */
129 /* Structure to record the size of a sequence of arguments
130 as the sum of a tree-expression and a constant. */
139 /* Add the value of the tree INC to the `struct args_size' TO. */
141 #define ADD_PARM_SIZE(TO, INC) \
142 { tree inc = (INC); \
143 if (TREE_CODE (inc) == INTEGER_CST) \
144 (TO).constant += TREE_INT_CST_LOW (inc); \
145 else if ((TO).var == 0) \
148 (TO).var = size_binop (PLUS_EXPR, (TO).var, inc); }
150 #define SUB_PARM_SIZE(TO, DEC) \
151 { tree dec = (DEC); \
152 if (TREE_CODE (dec) == INTEGER_CST) \
153 (TO).constant -= TREE_INT_CST_LOW (dec); \
154 else if ((TO).var == 0) \
155 (TO).var = size_binop (MINUS_EXPR, integer_zero_node, dec); \
157 (TO).var = size_binop (MINUS_EXPR, (TO).var, dec); }
159 /* Convert the implicit sum in a `struct args_size' into an rtx. */
160 #define ARGS_SIZE_RTX(SIZE) \
161 ((SIZE).var == 0 ? GEN_INT ((SIZE).constant) \
162 : expand_expr (size_binop (PLUS_EXPR, (SIZE).var, \
163 size_int ((SIZE).constant)), \
164 NULL_RTX, VOIDmode, 0))
166 /* Convert the implicit sum in a `struct args_size' into a tree. */
167 #define ARGS_SIZE_TREE(SIZE) \
168 ((SIZE).var == 0 ? size_int ((SIZE).constant) \
169 : size_binop (PLUS_EXPR, (SIZE).var, size_int ((SIZE).constant)))
171 /* Supply a default definition for FUNCTION_ARG_PADDING:
172 usually pad upward, but pad short args downward on
173 big-endian machines. */
175 enum direction {none, upward, downward}; /* Value has this type. */
177 #ifndef FUNCTION_ARG_PADDING
179 #define FUNCTION_ARG_PADDING(MODE, TYPE) \
180 (((MODE) == BLKmode \
181 ? ((TYPE) && TREE_CODE (TYPE_SIZE (TYPE)) == INTEGER_CST \
182 && int_size_in_bytes (TYPE) < PARM_BOUNDARY / BITS_PER_UNIT) \
183 : GET_MODE_BITSIZE (MODE) < PARM_BOUNDARY) \
186 #define FUNCTION_ARG_PADDING(MODE, TYPE) upward
190 /* Supply a default definition for FUNCTION_ARG_BOUNDARY. Normally, we let
191 FUNCTION_ARG_PADDING, which also pads the length, handle any needed
194 #ifndef FUNCTION_ARG_BOUNDARY
195 #define FUNCTION_ARG_BOUNDARY(MODE, TYPE) PARM_BOUNDARY
198 /* Nonzero if we do not know how to pass TYPE solely in registers.
199 We cannot do so in the following cases:
201 - if the type has variable size
202 - if the type is marked as addressable (it is required to be constructed
204 - if the padding and mode of the type is such that a copy into a register
205 would put it into the wrong part of the register.
207 /* Which padding can't be supported depends on the byte endianness.
209 A value in a register is implicitly padded at the most significant end.
210 On a big-endian machine, that is the lower end in memory.
211 So a value padded in memory at the upper end can't go in a register.
212 For a little-endian machine, the reverse is true. */
215 #define MUST_PASS_IN_STACK_BAD_PADDING upward
217 #define MUST_PASS_IN_STACK_BAD_PADDING downward
220 #define MUST_PASS_IN_STACK(MODE,TYPE) \
222 && (TREE_CODE (TYPE_SIZE (TYPE)) != INTEGER_CST \
223 || TREE_ADDRESSABLE (TYPE) \
224 || ((MODE) == BLKmode \
225 && (FUNCTION_ARG_PADDING (MODE, TYPE) \
226 == MUST_PASS_IN_STACK_BAD_PADDING))))
228 /* Nonzero if type TYPE should be returned in memory
229 (even though its mode is not BLKmode).
230 Most machines can use the following default definition. */
232 #ifndef RETURN_IN_MEMORY
233 #define RETURN_IN_MEMORY(TYPE) 0
236 /* Optabs are tables saying how to generate insn bodies
237 for various machine modes and numbers of operands.
238 Each optab applies to one operation.
239 For example, add_optab applies to addition.
241 The insn_code slot is the enum insn_code that says how to
242 generate an insn for this operation on a particular machine mode.
243 It is CODE_FOR_nothing if there is no such insn on the target machine.
245 The `lib_call' slot is the name of the library function that
246 can be used to perform the operation.
248 A few optabs, such as move_optab and cmp_optab, are used
251 /* Everything that uses expr.h needs to define enum insn_code
252 but we don't list it in the Makefile dependencies just for that. */
253 #include "insn-codes.h"
259 enum insn_code insn_code;
261 } handlers [NUM_MACHINE_MODES];
264 /* Given an enum insn_code, access the function to construct
265 the body of that kind of insn. */
266 #ifdef FUNCTION_CONVERSION_BUG
267 /* Some compilers fail to convert a function properly to a
268 pointer-to-function when used as an argument.
269 So produce the pointer-to-function directly.
270 Luckily, these compilers seem to work properly when you
271 call the pointer-to-function. */
272 #define GEN_FCN(CODE) (insn_gen_function[(int) (CODE)])
274 #define GEN_FCN(CODE) (*insn_gen_function[(int) (CODE)])
277 extern rtx (*const insn_gen_function[]) ();
279 extern optab add_optab;
280 extern optab sub_optab;
281 extern optab smul_optab; /* Signed and floating-point multiply */
282 extern optab smul_widen_optab; /* Signed multiply with result
283 one machine mode wider than args */
284 extern optab umul_widen_optab;
285 extern optab sdiv_optab; /* Signed divide */
286 extern optab sdivmod_optab; /* Signed divide-and-remainder in one */
287 extern optab udiv_optab;
288 extern optab udivmod_optab;
289 extern optab smod_optab; /* Signed remainder */
290 extern optab umod_optab;
291 extern optab flodiv_optab; /* Optab for floating divide. */
292 extern optab ftrunc_optab; /* Convert float to integer in float fmt */
293 extern optab and_optab; /* Logical and */
294 extern optab ior_optab; /* Logical or */
295 extern optab xor_optab; /* Logical xor */
296 extern optab ashl_optab; /* Arithmetic shift left */
297 extern optab ashr_optab; /* Arithmetic shift right */
298 extern optab lshl_optab; /* Logical shift left */
299 extern optab lshr_optab; /* Logical shift right */
300 extern optab rotl_optab; /* Rotate left */
301 extern optab rotr_optab; /* Rotate right */
302 extern optab smin_optab; /* Signed and floating-point minimum value */
303 extern optab smax_optab; /* Signed and floating-point maximum value */
304 extern optab umin_optab; /* Unsigned minimum value */
305 extern optab umax_optab; /* Unsigned maximum value */
307 extern optab mov_optab; /* Move instruction. */
308 extern optab movstrict_optab; /* Move, preserving high part of register. */
310 extern optab cmp_optab; /* Compare insn; two operands. */
311 extern optab tst_optab; /* tst insn; compare one operand against 0 */
313 /* Unary operations */
314 extern optab neg_optab; /* Negation */
315 extern optab abs_optab; /* Abs value */
316 extern optab one_cmpl_optab; /* Bitwise not */
317 extern optab ffs_optab; /* Find first bit set */
318 extern optab sqrt_optab; /* Square root */
319 extern optab sin_optab; /* Sine */
320 extern optab cos_optab; /* Cosine */
321 extern optab strlen_optab; /* String length */
323 /* Passed to expand_binop and expand_unop to say which options to try to use
324 if the requested operation can't be open-coded on the requisite mode.
325 Either OPTAB_LIB or OPTAB_LIB_WIDEN says try using a library call.
326 Either OPTAB_WIDEN or OPTAB_LIB_WIDEN says try using a wider mode.
327 OPTAB_MUST_WIDEN says try widening and don't try anything else. */
338 /* SYMBOL_REF rtx's for the library functions that are called
339 implicitly and not via optabs. */
341 extern rtx extendsfdf2_libfunc;
342 extern rtx extendsfxf2_libfunc;
343 extern rtx extendsftf2_libfunc;
344 extern rtx extenddfxf2_libfunc;
345 extern rtx extenddftf2_libfunc;
347 extern rtx truncdfsf2_libfunc;
348 extern rtx truncxfsf2_libfunc;
349 extern rtx trunctfsf2_libfunc;
350 extern rtx truncxfdf2_libfunc;
351 extern rtx trunctfdf2_libfunc;
353 extern rtx memcpy_libfunc;
354 extern rtx bcopy_libfunc;
355 extern rtx memcmp_libfunc;
356 extern rtx bcmp_libfunc;
357 extern rtx memset_libfunc;
358 extern rtx bzero_libfunc;
360 extern rtx eqsf2_libfunc;
361 extern rtx nesf2_libfunc;
362 extern rtx gtsf2_libfunc;
363 extern rtx gesf2_libfunc;
364 extern rtx ltsf2_libfunc;
365 extern rtx lesf2_libfunc;
367 extern rtx eqdf2_libfunc;
368 extern rtx nedf2_libfunc;
369 extern rtx gtdf2_libfunc;
370 extern rtx gedf2_libfunc;
371 extern rtx ltdf2_libfunc;
372 extern rtx ledf2_libfunc;
374 extern rtx eqxf2_libfunc;
375 extern rtx nexf2_libfunc;
376 extern rtx gtxf2_libfunc;
377 extern rtx gexf2_libfunc;
378 extern rtx ltxf2_libfunc;
379 extern rtx lexf2_libfunc;
381 extern rtx eqtf2_libfunc;
382 extern rtx netf2_libfunc;
383 extern rtx gttf2_libfunc;
384 extern rtx getf2_libfunc;
385 extern rtx lttf2_libfunc;
386 extern rtx letf2_libfunc;
388 extern rtx floatsisf_libfunc;
389 extern rtx floatdisf_libfunc;
390 extern rtx floattisf_libfunc;
392 extern rtx floatsidf_libfunc;
393 extern rtx floatdidf_libfunc;
394 extern rtx floattidf_libfunc;
396 extern rtx floatsixf_libfunc;
397 extern rtx floatdixf_libfunc;
398 extern rtx floattixf_libfunc;
400 extern rtx floatsitf_libfunc;
401 extern rtx floatditf_libfunc;
402 extern rtx floattitf_libfunc;
404 extern rtx fixsfsi_libfunc;
405 extern rtx fixsfdi_libfunc;
406 extern rtx fixsfti_libfunc;
408 extern rtx fixdfsi_libfunc;
409 extern rtx fixdfdi_libfunc;
410 extern rtx fixdfti_libfunc;
412 extern rtx fixxfsi_libfunc;
413 extern rtx fixxfdi_libfunc;
414 extern rtx fixxfti_libfunc;
416 extern rtx fixtfsi_libfunc;
417 extern rtx fixtfdi_libfunc;
418 extern rtx fixtfti_libfunc;
420 extern rtx fixunssfsi_libfunc;
421 extern rtx fixunssfdi_libfunc;
422 extern rtx fixunssfti_libfunc;
424 extern rtx fixunsdfsi_libfunc;
425 extern rtx fixunsdfdi_libfunc;
426 extern rtx fixunsdfti_libfunc;
428 extern rtx fixunsxfsi_libfunc;
429 extern rtx fixunsxfdi_libfunc;
430 extern rtx fixunsxfti_libfunc;
432 extern rtx fixunstfsi_libfunc;
433 extern rtx fixunstfdi_libfunc;
434 extern rtx fixunstfti_libfunc;
436 typedef rtx (*rtxfun) ();
438 /* Indexed by the rtx-code for a conditional (eg. EQ, LT,...)
439 gives the gen_function to make a branch to test that condition. */
441 extern rtxfun bcc_gen_fctn[NUM_RTX_CODE];
443 /* Indexed by the rtx-code for a conditional (eg. EQ, LT,...)
444 gives the insn code to make a store-condition insn
445 to test that condition. */
447 extern enum insn_code setcc_gen_code[NUM_RTX_CODE];
449 /* Expand a binary operation given optab and rtx operands. */
450 extern rtx expand_binop ();
452 /* Expand a binary operation with both signed and unsigned forms. */
453 extern rtx sign_expand_binop ();
455 /* Expand a unary arithmetic operation given optab rtx operand. */
456 extern rtx expand_unop ();
458 /* Expand the complex absolute value operation. */
459 extern rtx expand_complex_abs ();
461 /* Arguments MODE, RTX: return an rtx for the negation of that value.
463 extern rtx negate_rtx ();
465 /* Expand a logical AND operation. */
466 extern rtx expand_and ();
468 /* Emit a store-flag operation. */
469 extern rtx emit_store_flag ();
471 /* Return the CODE_LABEL rtx for a LABEL_DECL, creating it if necessary. */
472 extern rtx label_rtx ();
474 /* Given a JUMP_INSN, return a description of the test being made. */
475 extern rtx get_condition ();
477 /* Return the INSN_CODE to use for an extend operation. */
478 extern enum insn_code can_extend_p ();
480 /* Initialize the tables that control conversion between fixed and
482 extern void init_fixtab ();
483 extern void init_floattab ();
485 /* Generate code for a FIX_EXPR. */
486 extern void expand_fix ();
488 /* Generate code for a FLOAT_EXPR. */
489 extern void expand_float ();
491 /* Create but don't emit one rtl instruction to add one rtx into another.
492 Modes must match; operands must meet the operation's predicates.
493 Likewise for subtraction and for just copying.
494 These do not call protect_from_queue; caller must do so. */
495 extern rtx gen_add2_insn ();
496 extern rtx gen_sub2_insn ();
497 extern rtx gen_move_insn ();
499 /* Emit one rtl instruction to store zero in specified rtx. */
500 extern void emit_clr_insn ();
502 /* Emit one rtl insn to store 1 in specified rtx assuming it contains 0. */
503 extern void emit_0_to_1_insn ();
505 /* Emit one rtl insn to compare two rtx's. */
506 extern void emit_cmp_insn ();
508 /* Generate rtl to compare two rtx's, will call emit_cmp_insn. */
509 extern rtx compare_from_rtx ();
511 /* Emit some rtl insns to move data between rtx's, converting machine modes.
512 Both modes must be floating or both fixed. */
513 extern void convert_move ();
515 /* Convert an rtx to specified machine mode and return the result. */
516 extern rtx convert_to_mode ();
518 /* Emit code to push some arguments and call a library routine,
519 storing the value in a specified place. Calling sequence is
521 extern void emit_library_call ();
523 /* Given an rtx that may include add and multiply operations,
524 generate them as insns and return a pseudo-reg containing the value.
525 Useful after calling expand_expr with 1 as sum_ok. */
526 extern rtx force_operand ();
528 /* Return an rtx for the size in bytes of the value of an expr. */
529 extern rtx expr_size ();
531 extern rtx lookup_static_chain ();
533 /* Indicate how an input argument register was promoted. */
534 extern rtx promoted_input_arg ();
536 /* Return an rtx like arg but sans any constant terms.
537 Returns the original rtx if it has no constant terms.
538 The constant terms are added and stored via a second arg. */
539 extern rtx eliminate_constant_term ();
541 /* Convert arg to a valid memory address for specified machine mode,
542 by emitting insns to perform arithmetic if nec. */
543 extern rtx memory_address ();
545 /* Like `memory_address' but pretent `flag_force_addr' is 0. */
546 extern rtx memory_address_noforce ();
548 /* Return a memory reference like MEMREF, but with its mode changed
549 to MODE and its address changed to ADDR.
550 (VOIDmode means don't change the mode.
551 NULL for ADDR means don't change the address.) */
552 extern rtx change_address ();
554 /* Return a memory reference like MEMREF, but which is known to have a
557 extern rtx validize_mem ();
559 /* Convert a stack slot address ADDR valid in function FNDECL
560 into an address valid in this function (using a static chain). */
561 extern rtx fix_lexical_addr ();
563 /* Return the address of the trampoline for entering nested fn FUNCTION. */
564 extern rtx trampoline_address ();
566 /* Assemble the static constant template for function entry trampolines. */
567 extern rtx assemble_trampoline_template ();
569 /* Return 1 if two rtx's are equivalent in structure and elements. */
570 extern int rtx_equal_p ();
572 /* Given rtx, return new rtx whose address won't be affected by
573 any side effects. It has been copied to a new temporary reg. */
574 extern rtx stabilize ();
576 /* Given an rtx, copy all regs it refers to into new temps
577 and return a modified copy that refers to the new temps. */
578 extern rtx copy_all_regs ();
580 /* Copy given rtx to a new temp reg and return that. */
581 extern rtx copy_to_reg ();
583 /* Like copy_to_reg but always make the reg Pmode. */
584 extern rtx copy_addr_to_reg ();
586 /* Like copy_to_reg but always make the reg the specified mode MODE. */
587 extern rtx copy_to_mode_reg ();
589 /* Copy given rtx to given temp reg and return that. */
590 extern rtx copy_to_suggested_reg ();
592 /* Copy a value to a register if it isn't already a register.
593 Args are mode (in case value is a constant) and the value. */
594 extern rtx force_reg ();
596 /* Return given rtx, copied into a new temp reg if it was in memory. */
597 extern rtx force_not_mem ();
599 /* Remove some bytes from the stack. An rtx says how many. */
600 extern void adjust_stack ();
602 /* Add some bytes to the stack. An rtx says how many. */
603 extern void anti_adjust_stack ();
605 /* This enum is used for the following two functions. */
606 enum save_level {SAVE_BLOCK, SAVE_FUNCTION, SAVE_NONLOCAL};
608 /* Save the stack pointer at the specified level. */
609 extern void emit_stack_save ();
611 /* Restore the stack pointer from a save area of the specified level. */
612 extern void emit_stack_restore ();
614 /* Allocate some space on the stack dynamically and return its address. An rtx
615 says how many bytes. */
616 extern rtx allocate_dynamic_stack_space ();
618 /* Emit code to copy function value to a new temp reg and return that reg. */
619 extern rtx function_value ();
621 /* Return an rtx that refers to the value returned by a function
622 in its original home. This becomes invalid if any more code is emitted. */
623 extern rtx hard_function_value ();
625 /* Return an rtx that refers to the value returned by a library call
626 in its original home. This becomes invalid if any more code is emitted. */
627 extern rtx hard_libcall_value ();
629 /* Emit code to copy function value to a specified place. */
630 extern void copy_function_value ();
632 /* Given an rtx, return an rtx for a value rounded up to a multiple
633 of STACK_BOUNDARY / BITS_PER_UNIT. */
634 extern rtx round_push ();
636 /* Push a block of length SIZE (perhaps variable)
637 and return an rtx to address the beginning of the block. */
638 extern rtx push_block ();
640 /* Generate code for computing expression EXP,
641 and storing the value into TARGET.
642 If SUGGEST_REG is nonzero, copy the value through a register
643 and return that register, if that is possible. */
644 extern rtx store_expr ();
646 extern rtx prepare_call_address ();
647 extern rtx expand_call ();
648 extern void emit_call_1 ();
650 extern void emit_block_move ();
651 extern void emit_push_insn ();
652 extern void use_regs ();
653 extern void move_block_to_reg ();
655 extern rtx store_bit_field ();
656 extern rtx extract_bit_field ();
657 extern rtx expand_shift ();
658 extern rtx expand_mult ();
659 extern rtx expand_divmod ();
660 extern rtx expand_mult_add ();
661 extern rtx expand_stmt_expr ();
662 extern rtx emit_no_conflict_block ();
663 extern void emit_libcall_block ();
665 extern void jumpifnot ();
666 extern void jumpif ();
667 extern void do_jump ();
669 extern rtx assemble_static_space ();
671 extern void locate_and_pad_parm ();
673 extern rtx expand_inline_function ();
675 /* Hook called by expand_expr for language-specific tree codes.
676 It is up to the language front end to install a hook
677 if it has any such codes that expand_expr needs to know about. */
678 extern rtx (*lang_expand_expr) ();