Daily bump.
[official-gcc.git] / gcc / lists.c
blob0adacfb5162f7232687bc57019a1f419f33976c1
1 /* List management for the GNU C-Compiler expander.
2 Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999 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. */
22 #include "config.h"
23 #include "system.h"
24 #include "toplev.h"
25 #include "rtl.h"
26 #include "ggc.h"
28 static void free_list PARAMS ((rtx *, rtx *));
29 static void zap_lists PARAMS ((void *));
31 /* Functions for maintaining cache-able lists of EXPR_LIST and INSN_LISTs. */
33 /* An INSN_LIST containing all INSN_LISTs allocated but currently unused. */
34 static rtx unused_insn_list;
36 /* An EXPR_LIST containing all EXPR_LISTs allocated but currently unused. */
37 static rtx unused_expr_list;
40 /* This function will free an entire list of either EXPR_LIST or INSN_LIST
41 nodes. This is to be used only only lists that consist exclusively of
42 nodes of one type only. This is only called by free_EXPR_LIST_list
43 and free_INSN_LIST_list. */
44 static void
45 free_list (listp, unused_listp)
46 rtx *listp, *unused_listp;
48 rtx link, prev_link;
50 prev_link = *listp;
51 link = XEXP (prev_link, 1);
53 while (link)
55 prev_link = link;
56 link = XEXP (link, 1);
59 XEXP (prev_link, 1) = *unused_listp;
60 *unused_listp = *listp;
61 *listp = 0;
64 /* This call is used in place of a gen_rtx_INSN_LIST. If there is a cached
65 node available, we'll use it, otherwise a call to gen_rtx_INSN_LIST
66 is made. */
67 rtx
68 alloc_INSN_LIST (val, next)
69 rtx val, next;
71 rtx r;
73 if (unused_insn_list)
75 r = unused_insn_list;
76 unused_insn_list = XEXP (r, 1);
77 XEXP (r, 0) = val;
78 XEXP (r, 1) = next;
79 PUT_REG_NOTE_KIND (r, VOIDmode);
81 else
82 r = gen_rtx_INSN_LIST (VOIDmode, val, next);
84 return r;
87 /* This call is used in place of a gen_rtx_EXPR_LIST. If there is a cached
88 node available, we'll use it, otherwise a call to gen_rtx_EXPR_LIST
89 is made. */
90 rtx
91 alloc_EXPR_LIST (kind, val, next)
92 int kind;
93 rtx val, next;
95 rtx r;
97 if (unused_expr_list)
99 r = unused_expr_list;
100 unused_expr_list = XEXP (r, 1);
101 XEXP (r, 0) = val;
102 XEXP (r, 1) = next;
103 PUT_REG_NOTE_KIND (r, kind);
105 else
106 r = gen_rtx_EXPR_LIST (kind, val, next);
108 return r;
111 /* This function will initialize the EXPR_LIST and INSN_LIST caches. */
113 static void
114 zap_lists (dummy)
115 void *dummy ATTRIBUTE_UNUSED;
117 unused_expr_list = NULL;
118 unused_insn_list = NULL;
121 void
122 init_EXPR_INSN_LIST_cache ()
124 ggc_add_root (&unused_expr_list, 1, 1, zap_lists);
127 /* This function will free up an entire list of EXPR_LIST nodes. */
128 void
129 free_EXPR_LIST_list (listp)
130 rtx *listp;
132 if (*listp == 0)
133 return;
134 free_list (listp, &unused_expr_list);
137 /* This function will free up an entire list of INSN_LIST nodes. */
138 void
139 free_INSN_LIST_list (listp)
140 rtx *listp;
142 if (*listp == 0)
143 return;
144 free_list (listp, &unused_insn_list);
147 /* This function will free up an individual EXPR_LIST node. */
148 void
149 free_EXPR_LIST_node (ptr)
150 rtx ptr;
152 XEXP (ptr, 1) = unused_expr_list;
153 unused_expr_list = ptr;
156 /* This function will free up an individual INSN_LIST node. */
157 void
158 free_INSN_LIST_node (ptr)
159 rtx ptr;
161 XEXP (ptr, 1) = unused_insn_list;
162 unused_insn_list = ptr;