Remove some compile time warnings about duplicate definitions.
[official-gcc.git] / gcc / regs.h
blobe55c807fb6860849f8a3b7d03b30eed7d56d5b11
1 /* Define per-register tables for data flow info and register allocation.
2 Copyright (C) 1987, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
10 version.
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
20 02111-1307, USA. */
23 #include "varray.h"
25 #define REG_BYTES(R) mode_size[(int) GET_MODE (R)]
27 /* Get the number of consecutive hard regs required to hold the REG or
28 SUBREG rtx R.
29 When something may be an explicit hard reg, REG_SIZE is the only
30 valid way to get this value. You cannot get it from the regno.
32 A target may override this definition, the case where you would do
33 this is where there are registers which are smaller than WORD_SIZE
34 such as the SFmode registers on sparc64. */
36 #ifndef REG_SIZE
37 #define REG_SIZE(R) \
38 ((mode_size[(int) GET_MODE (R)] + UNITS_PER_WORD - 1) / UNITS_PER_WORD)
39 #endif
41 /* When you only have the mode of a pseudo register before it has a hard
42 register chosen for it, this reports the size of each hard register
43 a pseudo in such a mode would get allocated to. Like REG_SIZE, a
44 target may override this. */
46 #ifndef REGMODE_NATURAL_SIZE
47 #define REGMODE_NATURAL_SIZE(MODE) UNITS_PER_WORD
48 #endif
50 #ifndef SMALL_REGISTER_CLASSES
51 #define SMALL_REGISTER_CLASSES 0
52 #endif
54 /* Maximum register number used in this function, plus one. */
56 extern int max_regno;
58 /* Register information indexed by register number */
59 typedef struct reg_info_def
60 { /* fields set by reg_scan */
61 int first_uid; /* UID of first insn to use (REG n) */
62 int last_uid; /* UID of last insn to use (REG n) */
63 int last_note_uid; /* UID of last note to use (REG n) */
65 /* fields set by reg_scan & flow_analysis */
66 int sets; /* # of times (REG n) is set */
68 /* fields set by flow_analysis */
69 int refs; /* # of times (REG n) is used or set */
70 int freq; /* # estimated frequency (REG n) is used or set */
71 int deaths; /* # of times (REG n) dies */
72 int live_length; /* # of instructions (REG n) is live */
73 int calls_crossed; /* # of calls (REG n) is live across */
74 int basic_block; /* # of basic blocks (REG n) is used in */
75 char changes_mode; /* whether (SUBREG (REG n)) exists and
76 is illegal. */
77 } reg_info;
79 extern varray_type reg_n_info;
81 /* Indexed by n, gives number of times (REG n) is used or set. */
83 #define REG_N_REFS(N) (VARRAY_REG (reg_n_info, N)->refs)
85 /* Estimate frequency of references to register N. */
87 #define REG_FREQ(N) (VARRAY_REG (reg_n_info, N)->freq)
89 /* The weights for each insn varries from 0 to REG_FREQ_BASE.
90 This constant does not need to be high, as in infrequently executed
91 regions we want to count instructions equivalently to optimize for
92 size instead of speed. */
93 #define REG_FREQ_MAX 1000
95 /* Compute register frequency from the BB frequency. When optimizing for size,
96 or profile driven feedback is available and the function is never executed,
97 frequency is always equivalent. Otherwise rescale the basic block
98 frequency. */
99 #define REG_FREQ_FROM_BB(bb) (optimize_size \
100 || (flag_branch_probabilities \
101 && !ENTRY_BLOCK_PTR->count) \
102 ? REG_FREQ_MAX \
103 : ((bb)->frequency * REG_FREQ_MAX / BB_FREQ_MAX)\
104 ? ((bb)->frequency * REG_FREQ_MAX / BB_FREQ_MAX)\
105 : 1)
107 /* Indexed by n, gives number of times (REG n) is set.
108 ??? both regscan and flow allocate space for this. We should settle
109 on just copy. */
111 #define REG_N_SETS(N) (VARRAY_REG (reg_n_info, N)->sets)
113 /* Indexed by N, gives number of insns in which register N dies.
114 Note that if register N is live around loops, it can die
115 in transitions between basic blocks, and that is not counted here.
116 So this is only a reliable indicator of how many regions of life there are
117 for registers that are contained in one basic block. */
119 #define REG_N_DEATHS(N) (VARRAY_REG (reg_n_info, N)->deaths)
121 /* Indexed by N; says whether a pseudo register N was ever used
122 within a SUBREG that changes the mode of the reg in some way
123 that is illegal for a given class (usually floating-point)
124 of registers. */
126 #define REG_CHANGES_MODE(N) (VARRAY_REG (reg_n_info, N)->changes_mode)
128 /* Get the number of consecutive words required to hold pseudo-reg N. */
130 #define PSEUDO_REGNO_SIZE(N) \
131 ((GET_MODE_SIZE (PSEUDO_REGNO_MODE (N)) + UNITS_PER_WORD - 1) \
132 / UNITS_PER_WORD)
134 /* Get the number of bytes required to hold pseudo-reg N. */
136 #define PSEUDO_REGNO_BYTES(N) \
137 GET_MODE_SIZE (PSEUDO_REGNO_MODE (N))
139 /* Get the machine mode of pseudo-reg N. */
141 #define PSEUDO_REGNO_MODE(N) GET_MODE (regno_reg_rtx[N])
143 /* Indexed by N, gives number of CALL_INSNS across which (REG n) is live. */
145 #define REG_N_CALLS_CROSSED(N) (VARRAY_REG (reg_n_info, N)->calls_crossed)
147 /* Total number of instructions at which (REG n) is live.
148 The larger this is, the less priority (REG n) gets for
149 allocation in a hard register (in global-alloc).
150 This is set in flow.c and remains valid for the rest of the compilation
151 of the function; it is used to control register allocation.
153 local-alloc.c may alter this number to change the priority.
155 Negative values are special.
156 -1 is used to mark a pseudo reg which has a constant or memory equivalent
157 and is used infrequently enough that it should not get a hard register.
158 -2 is used to mark a pseudo reg for a parameter, when a frame pointer
159 is not required. global.c makes an allocno for this but does
160 not try to assign a hard register to it. */
162 #define REG_LIVE_LENGTH(N) (VARRAY_REG (reg_n_info, N)->live_length)
164 /* Vector of substitutions of register numbers,
165 used to map pseudo regs into hardware regs.
167 This can't be folded into reg_n_info without changing all of the
168 machine dependent directories, since the reload functions
169 in the machine dependent files access it. */
171 extern short *reg_renumber;
173 /* Vector indexed by hardware reg
174 saying whether that reg is ever used. */
176 extern char regs_ever_live[FIRST_PSEUDO_REGISTER];
178 /* Vector indexed by hardware reg giving its name. */
180 extern const char * reg_names[FIRST_PSEUDO_REGISTER];
182 /* For each hard register, the widest mode object that it can contain.
183 This will be a MODE_INT mode if the register can hold integers. Otherwise
184 it will be a MODE_FLOAT or a MODE_CC mode, whichever is valid for the
185 register. */
187 extern enum machine_mode reg_raw_mode[FIRST_PSEUDO_REGISTER];
189 /* Vector indexed by regno; gives uid of first insn using that reg.
190 This is computed by reg_scan for use by cse and loop.
191 It is sometimes adjusted for subsequent changes during loop,
192 but not adjusted by cse even if cse invalidates it. */
194 #define REGNO_FIRST_UID(N) (VARRAY_REG (reg_n_info, N)->first_uid)
196 /* Vector indexed by regno; gives uid of last insn using that reg.
197 This is computed by reg_scan for use by cse and loop.
198 It is sometimes adjusted for subsequent changes during loop,
199 but not adjusted by cse even if cse invalidates it.
200 This is harmless since cse won't scan through a loop end. */
202 #define REGNO_LAST_UID(N) (VARRAY_REG (reg_n_info, N)->last_uid)
204 /* Similar, but includes insns that mention the reg in their notes. */
206 #define REGNO_LAST_NOTE_UID(N) (VARRAY_REG (reg_n_info, N)->last_note_uid)
208 /* List made of EXPR_LIST rtx's which gives pairs of pseudo registers
209 that have to go in the same hard reg. */
210 extern rtx regs_may_share;
212 /* Flag set by local-alloc or global-alloc if they decide to allocate
213 something in a call-clobbered register. */
215 extern int caller_save_needed;
217 /* Predicate to decide whether to give a hard reg to a pseudo which
218 is referenced REFS times and would need to be saved and restored
219 around a call CALLS times. */
221 #ifndef CALLER_SAVE_PROFITABLE
222 #define CALLER_SAVE_PROFITABLE(REFS, CALLS) (4 * (CALLS) < (REFS))
223 #endif
225 /* On most machines a register class is likely to be spilled if it
226 only has one register. */
227 #ifndef CLASS_LIKELY_SPILLED_P
228 #define CLASS_LIKELY_SPILLED_P(CLASS) (reg_class_size[(int) (CLASS)] == 1)
229 #endif
231 /* Select a register mode required for caller save of hard regno REGNO. */
232 #ifndef HARD_REGNO_CALLER_SAVE_MODE
233 #define HARD_REGNO_CALLER_SAVE_MODE(REGNO, NREGS, MODE) \
234 choose_hard_reg_mode (REGNO, NREGS)
235 #endif
237 /* Registers that get partially clobbered by a call in a given mode.
238 These must not be call used registers. */
239 #ifndef HARD_REGNO_CALL_PART_CLOBBERED
240 #define HARD_REGNO_CALL_PART_CLOBBERED(REGNO, MODE) 0
241 #endif
243 /* Allocate reg_n_info tables */
244 extern void allocate_reg_info PARAMS ((size_t, int, int));