[thirdparty/gcc.git] / gcc / reload.h

/* Communication between reload.c and reload1.c.
   Copyright (C) 1987, 91-95, 97, 1998 Free Software Foundation, Inc.

This file is part of GNU CC.

GNU CC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU CC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU CC; see the file COPYING.  If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */


/* If secondary reloads are the same for inputs and outputs, define those
   macros here.  */

#ifdef SECONDARY_RELOAD_CLASS
#define SECONDARY_INPUT_RELOAD_CLASS(CLASS, MODE, X) \
  SECONDARY_RELOAD_CLASS (CLASS, MODE, X)
#define SECONDARY_OUTPUT_RELOAD_CLASS(CLASS, MODE, X) \
  SECONDARY_RELOAD_CLASS (CLASS, MODE, X)
#endif

/* If either macro is defined, show that we need secondary reloads.  */
#if defined(SECONDARY_INPUT_RELOAD_CLASS) || defined(SECONDARY_OUTPUT_RELOAD_CLASS)
#define HAVE_SECONDARY_RELOADS
#endif

/* If MEMORY_MOVE_COST isn't defined, give it a default here.  */
#ifndef MEMORY_MOVE_COST
#ifdef HAVE_SECONDARY_RELOADS
#define MEMORY_MOVE_COST(MODE,CLASS,IN) \
  (4 + memory_move_secondary_cost ((MODE), (CLASS), (IN)))
#else
#define MEMORY_MOVE_COST(MODE,CLASS,IN) 4
#endif
#endif
extern int memory_move_secondary_cost PROTO ((enum machine_mode, enum reg_class, int));

/* See reload.c and reload1.c for comments on these variables.  */

/* Maximum number of reloads we can need.  */
#define MAX_RELOADS (2 * MAX_RECOG_OPERANDS * (MAX_REGS_PER_ADDRESS + 1))

extern enum reg_class reload_address_base_reg_class;
extern enum reg_class reload_address_index_reg_class;
extern rtx reload_in[MAX_RELOADS];
extern rtx reload_out[MAX_RELOADS];
extern rtx reload_in_reg[MAX_RELOADS];
extern enum reg_class reload_reg_class[MAX_RELOADS];
extern enum machine_mode reload_inmode[MAX_RELOADS];
extern enum machine_mode reload_outmode[MAX_RELOADS];
extern char reload_optional[MAX_RELOADS];
extern char reload_nongroup[MAX_RELOADS];
extern int reload_inc[MAX_RELOADS];
extern int reload_opnum[MAX_RELOADS];
extern int reload_secondary_p[MAX_RELOADS];
extern int reload_secondary_in_reload[MAX_RELOADS];
extern int reload_secondary_out_reload[MAX_RELOADS];
#ifdef MAX_INSN_CODE
extern enum insn_code reload_secondary_in_icode[MAX_RELOADS];
extern enum insn_code reload_secondary_out_icode[MAX_RELOADS];
#endif
extern int n_reloads;

extern rtx reload_reg_rtx[MAX_RELOADS];

/* Encode the usage of a reload.  The following codes are supported:

   RELOAD_FOR_INPUT		reload of an input operand
   RELOAD_FOR_OUTPUT		likewise, for output
   RELOAD_FOR_INSN		a reload that must not conflict with anything
				used in the insn, but may conflict with
				something used before or after the insn
   RELOAD_FOR_INPUT_ADDRESS	reload for parts of the address of an object
				that is an input reload
   RELOAD_FOR_INPADDR_ADDRESS	reload needed for RELOAD_FOR_INPUT_ADDRESS
   RELOAD_FOR_OUTPUT_ADDRESS	like RELOAD_FOR INPUT_ADDRESS, for output
   RELOAD_FOR_OUTADDR_ADDRESS	reload needed for RELOAD_FOR_OUTPUT_ADDRESS
   RELOAD_FOR_OPERAND_ADDRESS	reload for the address of a non-reloaded
				operand; these don't conflict with
				any other addresses.
   RELOAD_FOR_OPADDR_ADDR	reload needed for RELOAD_FOR_OPERAND_ADDRESS
                                reloads; usually secondary reloads
   RELOAD_OTHER			none of the above, usually multiple uses
   RELOAD_FOR_OTHER_ADDRESS     reload for part of the address of an input
   				that is marked RELOAD_OTHER.

   This used to be "enum reload_when_needed" but some debuggers have trouble
   with an enum tag and variable of the same name.  */

enum reload_type
{
  RELOAD_FOR_INPUT, RELOAD_FOR_OUTPUT, RELOAD_FOR_INSN, 
  RELOAD_FOR_INPUT_ADDRESS, RELOAD_FOR_INPADDR_ADDRESS,
  RELOAD_FOR_OUTPUT_ADDRESS, RELOAD_FOR_OUTADDR_ADDRESS,
  RELOAD_FOR_OPERAND_ADDRESS, RELOAD_FOR_OPADDR_ADDR,
  RELOAD_OTHER, RELOAD_FOR_OTHER_ADDRESS
};

extern enum reload_type reload_when_needed[MAX_RELOADS];

extern rtx *reg_equiv_constant;
extern rtx *reg_equiv_memory_loc;
extern rtx *reg_equiv_address;
extern rtx *reg_equiv_mem;

/* All the "earlyclobber" operands of the current insn
   are recorded here.  */
extern int n_earlyclobbers;
extern rtx reload_earlyclobbers[MAX_RECOG_OPERANDS];

/* Save the number of operands.  */
extern int reload_n_operands;

/* First uid used by insns created by reload in this function.
   Used in find_equiv_reg.  */
extern int reload_first_uid;

/* Nonzero if indirect addressing is supported when the innermost MEM is
   of the form (MEM (SYMBOL_REF sym)).  It is assumed that the level to
   which these are valid is the same as spill_indirect_levels, above.   */

extern char indirect_symref_ok;

/* Nonzero if an address (plus (reg frame_pointer) (reg ...)) is valid.  */
extern char double_reg_address_ok;

#ifdef MAX_INSN_CODE
/* These arrays record the insn_code of insns that may be needed to
   perform input and output reloads of special objects.  They provide a
   place to pass a scratch register.  */
extern enum insn_code reload_in_optab[];
extern enum insn_code reload_out_optab[];
#endif

/* Functions from reload.c:  */

/* Return a memory location that will be used to copy X in mode MODE.  
   If we haven't already made a location for this mode in this insn,
   call find_reloads_address on the location being returned.  */
extern rtx get_secondary_mem PROTO((rtx, enum machine_mode,
				    int, enum reload_type));

/* Clear any secondary memory locations we've made.  */
extern void clear_secondary_mem PROTO((void));

/* Transfer all replacements that used to be in reload FROM to be in
   reload TO.  */
extern void transfer_replacements PROTO((int, int));

/* Like rtx_equal_p except that it allows a REG and a SUBREG to match
   if they are the same hard reg, and has special hacks for
   autoincrement and autodecrement.  */
extern int operands_match_p PROTO((rtx, rtx));

/* Return the number of times character C occurs in string S.  */
extern int n_occurrences PROTO((int, char *));

/* Return 1 if altering OP will not modify the value of CLOBBER. */
extern int safe_from_earlyclobber PROTO((rtx, rtx));

/* Search the body of INSN for values that need reloading and record them
   with push_reload.  REPLACE nonzero means record also where the values occur
   so that subst_reloads can be used.  */
extern void find_reloads PROTO((rtx, int, int, int, short *));

/* Compute the sum of X and Y, making canonicalizations assumed in an
   address, namely: sum constant integers, surround the sum of two
   constants with a CONST, put the constant as the second operand, and
   group the constant on the outermost sum.  */
extern rtx form_sum PROTO((rtx, rtx));

/* Substitute into the current INSN the registers into which we have reloaded
   the things that need reloading.  */
extern void subst_reloads PROTO((void));

/* Make a copy of any replacements being done into X and move those copies
   to locations in Y, a copy of X.  We only look at the highest level of
   the RTL.  */
extern void copy_replacements PROTO((rtx, rtx));

/* Change any replacements being done to *X to be done to *Y */
extern void move_replacements PROTO((rtx *x, rtx *y));

/* If LOC was scheduled to be replaced by something, return the replacement.
   Otherwise, return *LOC.  */
extern rtx find_replacement PROTO((rtx *));

/* Return nonzero if register in range [REGNO, ENDREGNO)
   appears either explicitly or implicitly in X
   other than being stored into.  */
extern int refers_to_regno_for_reload_p PROTO((int, int, rtx, rtx *));

/* Nonzero if modifying X will affect IN.  */
extern int reg_overlap_mentioned_for_reload_p PROTO((rtx, rtx));

/* Return nonzero if anything in X contains a MEM.  Look also for pseudo
   registers.  */
extern int refers_to_mem_for_reload_p PROTO((rtx));

/* Check the insns before INSN to see if there is a suitable register
   containing the same value as GOAL.  */
extern rtx find_equiv_reg PROTO((rtx, rtx, enum reg_class, int, short *,
				 int, enum machine_mode));

/* Return 1 if register REGNO is the subject of a clobber in insn INSN.  */
extern int regno_clobbered_p PROTO((int, rtx));

/* Functions in reload1.c:  */

extern int reloads_conflict		PROTO ((int, int));

int count_occurrences            PROTO((rtx, rtx));

/* Initialize the reload pass once per compilation.  */
extern void init_reload PROTO((void));

/* The reload pass itself.  */
extern int reload PROTO((rtx, int, FILE *));

/* Mark the slots in regs_ever_live for the hard regs
   used by pseudo-reg number REGNO.  */
extern void mark_home_live PROTO((int));

/* Scan X and replace any eliminable registers (such as fp) with a
   replacement (such as sp), plus an offset.  */
extern rtx eliminate_regs PROTO((rtx, enum machine_mode, rtx));

/* Emit code to perform a reload from IN (which may be a reload register) to
   OUT (which may also be a reload register).  IN or OUT is from operand
   OPNUM with reload type TYPE.  */
extern rtx gen_reload PROTO((rtx, rtx, int, enum reload_type));

/* Functions in caller-save.c:  */

/* Initialize for caller-save.  */
extern void init_caller_save PROTO((void));

/* Initialize save areas by showing that we haven't allocated any yet.  */
extern void init_save_areas PROTO((void));

/* Allocate save areas for any hard registers that might need saving.  */
extern int setup_save_areas PROTO((int *));

/* Find the places where hard regs are live across calls and save them.  */
extern void save_call_clobbered_regs PROTO((enum machine_mode));
Commit	Line	Data
b4e0cbb5	1	/* Communication between reload.c and reload1.c.
f5963e61	2	Copyright (C) 1987, 91-95, 97, 1998 Free Software Foundation, Inc.
b4e0cbb5 RK	3
	4	This file is part of GNU CC.
	5
	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)
	9	any later version.
	10
	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.
	15
	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
e99215a3 RK	18	the Free Software Foundation, 59 Temple Place - Suite 330,
e99215a3 RK	19	Boston, MA 02111-1307, USA. */
b4e0cbb5 RK	20
b4e0cbb5 RK	21
defc614f RK	22	/* If secondary reloads are the same for inputs and outputs, define those
	23	macros here. */
	24
	25	#ifdef SECONDARY_RELOAD_CLASS
	26	#define SECONDARY_INPUT_RELOAD_CLASS(CLASS, MODE, X) \
	27	SECONDARY_RELOAD_CLASS (CLASS, MODE, X)
	28	#define SECONDARY_OUTPUT_RELOAD_CLASS(CLASS, MODE, X) \
	29	SECONDARY_RELOAD_CLASS (CLASS, MODE, X)
	30	#endif
	31
	32	/* If either macro is defined, show that we need secondary reloads. */
	33	#if defined(SECONDARY_INPUT_RELOAD_CLASS) \|\| defined(SECONDARY_OUTPUT_RELOAD_CLASS)
	34	#define HAVE_SECONDARY_RELOADS
	35	#endif
	36
cbd5b9a2 KR	37	/* If MEMORY_MOVE_COST isn't defined, give it a default here. */
	38	#ifndef MEMORY_MOVE_COST
	39	#ifdef HAVE_SECONDARY_RELOADS
	40	#define MEMORY_MOVE_COST(MODE,CLASS,IN) \
	41	(4 + memory_move_secondary_cost ((MODE), (CLASS), (IN)))
	42	#else
	43	#define MEMORY_MOVE_COST(MODE,CLASS,IN) 4
	44	#endif
	45	#endif
	46	extern int memory_move_secondary_cost PROTO ((enum machine_mode, enum reg_class, int));
	47
b4e0cbb5 RK	48	/* See reload.c and reload1.c for comments on these variables. */
	49
	50	/* Maximum number of reloads we can need. */
	51	#define MAX_RELOADS (2 * MAX_RECOG_OPERANDS * (MAX_REGS_PER_ADDRESS + 1))
	52
9c8ae275 ILT	53	extern enum reg_class reload_address_base_reg_class;
9c8ae275 ILT	54	extern enum reg_class reload_address_index_reg_class;
b4e0cbb5 RK	55	extern rtx reload_in[MAX_RELOADS];
	56	extern rtx reload_out[MAX_RELOADS];
	57	extern rtx reload_in_reg[MAX_RELOADS];
	58	extern enum reg_class reload_reg_class[MAX_RELOADS];
	59	extern enum machine_mode reload_inmode[MAX_RELOADS];
	60	extern enum machine_mode reload_outmode[MAX_RELOADS];
b4e0cbb5	61	extern char reload_optional[MAX_RELOADS];
f5963e61	62	extern char reload_nongroup[MAX_RELOADS];
b4e0cbb5	63	extern int reload_inc[MAX_RELOADS];
96c82232	64	extern int reload_opnum[MAX_RELOADS];
b4e0cbb5	65	extern int reload_secondary_p[MAX_RELOADS];
b3338715 RK	66	extern int reload_secondary_in_reload[MAX_RELOADS];
b3338715 RK	67	extern int reload_secondary_out_reload[MAX_RELOADS];
defc614f	68	#ifdef MAX_INSN_CODE
b3338715 RK	69	extern enum insn_code reload_secondary_in_icode[MAX_RELOADS];
b3338715 RK	70	extern enum insn_code reload_secondary_out_icode[MAX_RELOADS];
defc614f	71	#endif
b4e0cbb5 RK	72	extern int n_reloads;
	73
	74	extern rtx reload_reg_rtx[MAX_RELOADS];
	75
96c82232 RK	76	/* Encode the usage of a reload. The following codes are supported:
	77
	78	RELOAD_FOR_INPUT reload of an input operand
	79	RELOAD_FOR_OUTPUT likewise, for output
	80	RELOAD_FOR_INSN a reload that must not conflict with anything
	81	used in the insn, but may conflict with
	82	something used before or after the insn
	83	RELOAD_FOR_INPUT_ADDRESS reload for parts of the address of an object
	84	that is an input reload
47c8cf91 ILT	85	RELOAD_FOR_INPADDR_ADDRESS reload needed for RELOAD_FOR_INPUT_ADDRESS
	86	RELOAD_FOR_OUTPUT_ADDRESS like RELOAD_FOR INPUT_ADDRESS, for output
	87	RELOAD_FOR_OUTADDR_ADDRESS reload needed for RELOAD_FOR_OUTPUT_ADDRESS
96c82232 RK	88	RELOAD_FOR_OPERAND_ADDRESS reload for the address of a non-reloaded
	89	operand; these don't conflict with
	90	any other addresses.
ca8e02b0 RK	91	RELOAD_FOR_OPADDR_ADDR reload needed for RELOAD_FOR_OPERAND_ADDRESS
ca8e02b0 RK	92	reloads; usually secondary reloads
96c82232 RK	93	RELOAD_OTHER none of the above, usually multiple uses
	94	RELOAD_FOR_OTHER_ADDRESS reload for part of the address of an input
	95	that is marked RELOAD_OTHER.
	96
	97	This used to be "enum reload_when_needed" but some debuggers have trouble
	98	with an enum tag and variable of the same name. */
	99
	100	enum reload_type
b4e0cbb5	101	{
96c82232	102	RELOAD_FOR_INPUT, RELOAD_FOR_OUTPUT, RELOAD_FOR_INSN,
47c8cf91 ILT	103	RELOAD_FOR_INPUT_ADDRESS, RELOAD_FOR_INPADDR_ADDRESS,
47c8cf91 ILT	104	RELOAD_FOR_OUTPUT_ADDRESS, RELOAD_FOR_OUTADDR_ADDRESS,
ca8e02b0 RK	105	RELOAD_FOR_OPERAND_ADDRESS, RELOAD_FOR_OPADDR_ADDR,
ca8e02b0 RK	106	RELOAD_OTHER, RELOAD_FOR_OTHER_ADDRESS
b4e0cbb5 RK	107	};
b4e0cbb5 RK	108
96c82232	109	extern enum reload_type reload_when_needed[MAX_RELOADS];
b4e0cbb5 RK	110
b4e0cbb5 RK	111	extern rtx *reg_equiv_constant;
af189bf3	112	extern rtx *reg_equiv_memory_loc;
b4e0cbb5 RK	113	extern rtx *reg_equiv_address;
	114	extern rtx *reg_equiv_mem;
	115
	116	/* All the "earlyclobber" operands of the current insn
	117	are recorded here. */
	118	extern int n_earlyclobbers;
	119	extern rtx reload_earlyclobbers[MAX_RECOG_OPERANDS];
	120
96c82232 RK	121	/* Save the number of operands. */
	122	extern int reload_n_operands;
	123
b4e0cbb5 RK	124	/* First uid used by insns created by reload in this function.
	125	Used in find_equiv_reg. */
	126	extern int reload_first_uid;
	127
	128	/* Nonzero if indirect addressing is supported when the innermost MEM is
	129	of the form (MEM (SYMBOL_REF sym)). It is assumed that the level to
	130	which these are valid is the same as spill_indirect_levels, above. */
	131
	132	extern char indirect_symref_ok;
	133
	134	/* Nonzero if an address (plus (reg frame_pointer) (reg ...)) is valid. */
	135	extern char double_reg_address_ok;
	136
defc614f RK	137	#ifdef MAX_INSN_CODE
	138	/* These arrays record the insn_code of insns that may be needed to
	139	perform input and output reloads of special objects. They provide a
	140	place to pass a scratch register. */
	141	extern enum insn_code reload_in_optab[];
	142	extern enum insn_code reload_out_optab[];
	143	#endif
	144
96c82232 RK	145	/* Functions from reload.c: */
	146
	147	/* Return a memory location that will be used to copy X in mode MODE.
	148	If we haven't already made a location for this mode in this insn,
	149	call find_reloads_address on the location being returned. */
	150	extern rtx get_secondary_mem PROTO((rtx, enum machine_mode,
	151	int, enum reload_type));
	152
	153	/* Clear any secondary memory locations we've made. */
	154	extern void clear_secondary_mem PROTO((void));
	155
	156	/* Transfer all replacements that used to be in reload FROM to be in
	157	reload TO. */
	158	extern void transfer_replacements PROTO((int, int));
	159
96c82232 RK	160	/* Like rtx_equal_p except that it allows a REG and a SUBREG to match
	161	if they are the same hard reg, and has special hacks for
	162	autoincrement and autodecrement. */
	163	extern int operands_match_p PROTO((rtx, rtx));
	164
	165	/* Return the number of times character C occurs in string S. */
	166	extern int n_occurrences PROTO((int, char *));
	167
	168	/* Return 1 if altering OP will not modify the value of CLOBBER. */
	169	extern int safe_from_earlyclobber PROTO((rtx, rtx));
	170
	171	/* Search the body of INSN for values that need reloading and record them
	172	with push_reload. REPLACE nonzero means record also where the values occur
97ecb251	173	so that subst_reloads can be used. */
521f2d6f	174	extern void find_reloads PROTO((rtx, int, int, int, short *));
96c82232 RK	175
	176	/* Compute the sum of X and Y, making canonicalizations assumed in an
	177	address, namely: sum constant integers, surround the sum of two
	178	constants with a CONST, put the constant as the second operand, and
	179	group the constant on the outermost sum. */
	180	extern rtx form_sum PROTO((rtx, rtx));
	181
	182	/* Substitute into the current INSN the registers into which we have reloaded
	183	the things that need reloading. */
521f2d6f	184	extern void subst_reloads PROTO((void));
96c82232 RK	185
	186	/* Make a copy of any replacements being done into X and move those copies
	187	to locations in Y, a copy of X. We only look at the highest level of
	188	the RTL. */
	189	extern void copy_replacements PROTO((rtx, rtx));
	190
a9a2595b JR	191	/* Change any replacements being done to X to be done to Y */
	192	extern void move_replacements PROTO((rtx x, rtx y));
	193
96c82232 RK	194	/* If LOC was scheduled to be replaced by something, return the replacement.
96c82232 RK	195	Otherwise, return LOC. /
521f2d6f	196	extern rtx find_replacement PROTO((rtx *));
96c82232 RK	197
	198	/* Return nonzero if register in range [REGNO, ENDREGNO)
	199	appears either explicitly or implicitly in X
	200	other than being stored into. */
	201	extern int refers_to_regno_for_reload_p PROTO((int, int, rtx, rtx *));
	202
	203	/* Nonzero if modifying X will affect IN. */
	204	extern int reg_overlap_mentioned_for_reload_p PROTO((rtx, rtx));
	205
	206	/* Return nonzero if anything in X contains a MEM. Look also for pseudo
	207	registers. */
	208	extern int refers_to_mem_for_reload_p PROTO((rtx));
	209
	210	/* Check the insns before INSN to see if there is a suitable register
	211	containing the same value as GOAL. */
	212	extern rtx find_equiv_reg PROTO((rtx, rtx, enum reg_class, int, short *,
	213	int, enum machine_mode));
	214
	215	/* Return 1 if register REGNO is the subject of a clobber in insn INSN. */
	216	extern int regno_clobbered_p PROTO((int, rtx));
	217
96c82232 RK	218	/* Functions in reload1.c: */
96c82232 RK	219
d6f4ec51 KG	220	extern int reloads_conflict PROTO ((int, int));
d6f4ec51 KG	221
184bb750 R	222	int count_occurrences PROTO((rtx, rtx));
184bb750 R	223
96c82232 RK	224	/* Initialize the reload pass once per compilation. */
	225	extern void init_reload PROTO((void));
	226
	227	/* The reload pass itself. */
1914f5da	228	extern int reload PROTO((rtx, int, FILE *));
96c82232 RK	229
	230	/* Mark the slots in regs_ever_live for the hard regs
	231	used by pseudo-reg number REGNO. */
	232	extern void mark_home_live PROTO((int));
	233
	234	/* Scan X and replace any eliminable registers (such as fp) with a
	235	replacement (such as sp), plus an offset. */
1914f5da	236	extern rtx eliminate_regs PROTO((rtx, enum machine_mode, rtx));
96c82232	237
94bba16f RK	238	/* Emit code to perform a reload from IN (which may be a reload register) to
	239	OUT (which may also be a reload register). IN or OUT is from operand
	240	OPNUM with reload type TYPE. */
	241	extern rtx gen_reload PROTO((rtx, rtx, int, enum reload_type));
96c82232 RK	242
	243	/* Functions in caller-save.c: */
	244
	245	/* Initialize for caller-save. */
	246	extern void init_caller_save PROTO((void));
	247
	248	/* Initialize save areas by showing that we haven't allocated any yet. */
	249	extern void init_save_areas PROTO((void));
	250
	251	/* Allocate save areas for any hard registers that might need saving. */
	252	extern int setup_save_areas PROTO((int *));
	253
	254	/* Find the places where hard regs are live across calls and save them. */
	255	extern void save_call_clobbered_regs PROTO((enum machine_mode));