source: trunk/third/gcc/regs.h @ 8834

Revision 8834, 6.1 KB checked in by ghudson, 28 years ago (diff)
This commit was generated by cvs2svn to compensate for changes in r8833, which included commits to RCS files with non-trunk default branches.
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1/* Define per-register tables for data flow info and register allocation.
2   Copyright (C) 1987, 1993, 1994 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, 59 Temple Place - Suite 330,
19Boston, MA 02111-1307, USA.  */
20
21
22
23#define REG_BYTES(R) mode_size[(int) GET_MODE (R)]
24
25/* Get the number of consecutive hard regs required to hold the REG rtx R.
26   When something may be an explicit hard reg, REG_SIZE is the only
27   valid way to get this value.  You cannot get it from the regno.  */
28
29#define REG_SIZE(R) \
30  ((mode_size[(int) GET_MODE (R)] + UNITS_PER_WORD - 1) / UNITS_PER_WORD)
31
32/* Maximum register number used in this function, plus one.  */
33
34extern int max_regno;
35
36/* Maximum number of SCRATCH rtx's in each block of this function.  */
37
38extern int max_scratch;
39
40/* Indexed by n, gives number of times (REG n) is used or set.
41   References within loops may be counted more times.  */
42
43extern int *reg_n_refs;
44
45/* Indexed by n, gives number of times (REG n) is set.  */
46
47extern short *reg_n_sets;
48
49/* Indexed by N, gives number of insns in which register N dies.
50   Note that if register N is live around loops, it can die
51   in transitions between basic blocks, and that is not counted here.
52   So this is only a reliable indicator of how many regions of life there are
53   for registers that are contained in one basic block.  */
54
55extern short *reg_n_deaths;
56
57/* Indexed by N; says whether a pseudo register N was ever used
58   within a SUBREG that changes the size of the reg.  Some machines prohibit
59   such objects to be in certain (usually floating-point) registers.  */
60
61extern char *reg_changes_size;
62
63/* Get the number of consecutive words required to hold pseudo-reg N.  */
64
65#define PSEUDO_REGNO_SIZE(N) \
66  ((GET_MODE_SIZE (PSEUDO_REGNO_MODE (N)) + UNITS_PER_WORD - 1)         \
67   / UNITS_PER_WORD)
68
69/* Get the number of bytes required to hold pseudo-reg N.  */
70
71#define PSEUDO_REGNO_BYTES(N) \
72  GET_MODE_SIZE (PSEUDO_REGNO_MODE (N))
73
74/* Get the machine mode of pseudo-reg N.  */
75
76#define PSEUDO_REGNO_MODE(N) GET_MODE (regno_reg_rtx[N])
77
78/* Indexed by N, gives number of CALL_INSNS across which (REG n) is live.  */
79
80extern int *reg_n_calls_crossed;
81
82/* Total number of instructions at which (REG n) is live.
83   The larger this is, the less priority (REG n) gets for
84   allocation in a hard register (in global-alloc).
85   This is set in flow.c and remains valid for the rest of the compilation
86   of the function; it is used to control register allocation.
87
88   local-alloc.c may alter this number to change the priority.
89
90   Negative values are special.
91   -1 is used to mark a pseudo reg which has a constant or memory equivalent
92   and is used infrequently enough that it should not get a hard register.
93   -2 is used to mark a pseudo reg for a parameter, when a frame pointer
94   is not required.  global.c makes an allocno for this but does
95   not try to assign a hard register to it.  */
96
97extern int *reg_live_length;
98
99/* Vector of substitutions of register numbers,
100   used to map pseudo regs into hardware regs.  */
101
102extern short *reg_renumber;
103
104/* Vector indexed by hardware reg
105   saying whether that reg is ever used.  */
106
107extern char regs_ever_live[FIRST_PSEUDO_REGISTER];
108
109/* Vector indexed by hardware reg giving its name.  */
110
111extern char *reg_names[FIRST_PSEUDO_REGISTER];
112
113/* For each hard register, the widest mode object that it can contain.
114   This will be a MODE_INT mode if the register can hold integers.  Otherwise
115   it will be a MODE_FLOAT or a MODE_CC mode, whichever is valid for the
116   register.  */
117
118extern enum machine_mode reg_raw_mode[FIRST_PSEUDO_REGISTER];
119
120/* Vector indexed by regno; gives uid of first insn using that reg.
121   This is computed by reg_scan for use by cse and loop.
122   It is sometimes adjusted for subsequent changes during loop,
123   but not adjusted by cse even if cse invalidates it.  */
124
125extern int *regno_first_uid;
126
127/* Vector indexed by regno; gives uid of last insn using that reg.
128   This is computed by reg_scan for use by cse and loop.
129   It is sometimes adjusted for subsequent changes during loop,
130   but not adjusted by cse even if cse invalidates it.
131   This is harmless since cse won't scan through a loop end.  */
132
133extern int *regno_last_uid;
134
135/* Similar, but includes insns that mention the reg in their notes.  */
136
137extern int *regno_last_note_uid;
138
139/* Vector indexed by regno; contains 1 for a register is considered a pointer.
140   Reloading, etc. will use a pointer register rather than a non-pointer
141   as the base register in an address, when there is a choice of two regs.  */
142
143extern char *regno_pointer_flag;
144#define REGNO_POINTER_FLAG(REGNO) regno_pointer_flag[REGNO]
145
146/* List made of EXPR_LIST rtx's which gives pairs of pseudo registers
147   that have to go in the same hard reg.  */
148extern rtx regs_may_share;
149
150/* Vector mapping pseudo regno into the REG rtx for that register.
151   This is computed by reg_scan.  */
152
153extern rtx *regno_reg_rtx;
154
155/* Flag set by local-alloc or global-alloc if they decide to allocate
156   something in a call-clobbered register.  */
157
158extern int caller_save_needed;
159
160/* Predicate to decide whether to give a hard reg to a pseudo which
161   is referenced REFS times and would need to be saved and restored
162   around a call CALLS times.  */
163
164#ifndef CALLER_SAVE_PROFITABLE
165#define CALLER_SAVE_PROFITABLE(REFS, CALLS)  (4 * (CALLS) < (REFS))
166#endif
167
168/* Allocated in local_alloc.  */
169
170/* A list of SCRATCH rtl allocated by local-alloc.  */
171extern rtx *scratch_list;
172/* The basic block in which each SCRATCH is used.  */
173extern int *scratch_block;
174/* The length of the arrays pointed to by scratch_block and scratch_list.  */
175extern int scratch_list_length;
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