1 /* List management for the GCC expander.
2 Copyright (C) 1987-2018 Free Software Foundation, Inc.
3
4 This file is part of GCC.
5
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
9 version.
10
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
19
20 #include "config.h"
21 #include "system.h"
22 #include "coretypes.h"
23 #include "tm.h"
24 #include "rtl.h"
25
26 static void free_list (rtx *, rtx *);
27
28 /* Functions for maintaining cache-able lists of EXPR_LIST and INSN_LISTs. */
29
30 /* An INSN_LIST containing all INSN_LISTs allocated but currently unused. */
31 static GTY ((deletable)) rtx unused_insn_list;
32
33 /* An EXPR_LIST containing all EXPR_LISTs allocated but currently unused. */
34 static GTY ((deletable)) rtx unused_expr_list;
35
36 /* This function will free an entire list of either EXPR_LIST, INSN_LIST
37 or DEPS_LIST nodes. This is to be used only on lists that consist
38 exclusively of nodes of one type only. This is only called by
39 free_EXPR_LIST_list, free_INSN_LIST_list and free_DEPS_LIST_list. */
40 static void
free_list(rtx * listp,rtx * unused_listp)41 free_list (rtx *listp, rtx *unused_listp)
42 {
43 rtx link, prev_link;
44
45 prev_link = *listp;
46 link = XEXP (prev_link, 1);
47
48 gcc_assert (unused_listp != &unused_insn_list
49 || GET_CODE (prev_link) == INSN_LIST);
50
51 while (link)
52 {
53 gcc_assert (unused_listp != &unused_insn_list
54 || GET_CODE (prev_link) == INSN_LIST);
55
56 prev_link = link;
57 link = XEXP (link, 1);
58 }
59
60 XEXP (prev_link, 1) = *unused_listp;
61 *unused_listp = *listp;
62 *listp = 0;
63 }
64
65 /* Find corresponding to ELEM node in the list pointed to by LISTP.
66 This node must exist in the list. Returns pointer to that node. */
67 static rtx *
find_list_elem(rtx elem,rtx * listp)68 find_list_elem (rtx elem, rtx *listp)
69 {
70 while (XEXP (*listp, 0) != elem)
71 listp = &XEXP (*listp, 1);
72 return listp;
73 }
74
75 /* Remove the node pointed to by LISTP from the list. */
76 static void
remove_list_node(rtx * listp)77 remove_list_node (rtx *listp)
78 {
79 rtx node;
80
81 node = *listp;
82 *listp = XEXP (node, 1);
83 XEXP (node, 1) = 0;
84 }
85
86 /* Removes corresponding to ELEM node from the list pointed to by LISTP.
87 Returns that node. */
88 rtx
remove_list_elem(rtx elem,rtx * listp)89 remove_list_elem (rtx elem, rtx *listp)
90 {
91 rtx node;
92
93 listp = find_list_elem (elem, listp);
94 node = *listp;
95 remove_list_node (listp);
96 return node;
97 }
98
99 /* This call is used in place of a gen_rtx_INSN_LIST. If there is a cached
100 node available, we'll use it, otherwise a call to gen_rtx_INSN_LIST
101 is made. */
102 rtx_insn_list *
alloc_INSN_LIST(rtx val,rtx next)103 alloc_INSN_LIST (rtx val, rtx next)
104 {
105 rtx_insn_list *r;
106
107 if (unused_insn_list)
108 {
109 r = as_a <rtx_insn_list *> (unused_insn_list);
110 unused_insn_list = r->next ();
111 XEXP (r, 0) = val;
112 XEXP (r, 1) = next;
113 PUT_REG_NOTE_KIND (r, VOIDmode);
114
115 gcc_assert (GET_CODE (r) == INSN_LIST);
116 }
117 else
118 r = gen_rtx_INSN_LIST (VOIDmode, val, next);
119
120 return r;
121 }
122
123 /* This call is used in place of a gen_rtx_EXPR_LIST. If there is a cached
124 node available, we'll use it, otherwise a call to gen_rtx_EXPR_LIST
125 is made. */
126 rtx_expr_list *
alloc_EXPR_LIST(int kind,rtx val,rtx next)127 alloc_EXPR_LIST (int kind, rtx val, rtx next)
128 {
129 rtx_expr_list *r;
130
131 if (unused_expr_list)
132 {
133 r = as_a <rtx_expr_list *> (unused_expr_list);
134 unused_expr_list = XEXP (r, 1);
135 XEXP (r, 0) = val;
136 XEXP (r, 1) = next;
137 PUT_REG_NOTE_KIND (r, kind);
138 }
139 else
140 r = gen_rtx_EXPR_LIST ((machine_mode) kind, val, next);
141
142 return r;
143 }
144
145 /* This function will free up an entire list of EXPR_LIST nodes. */
146 void
free_EXPR_LIST_list(rtx_expr_list ** listp)147 free_EXPR_LIST_list (rtx_expr_list **listp)
148 {
149 if (*listp == 0)
150 return;
151 free_list ((rtx *)listp, &unused_expr_list);
152 }
153
154 /* This function will free up an entire list of INSN_LIST nodes. */
155 void
free_INSN_LIST_list(rtx_insn_list ** listp)156 free_INSN_LIST_list (rtx_insn_list **listp)
157 {
158 if (*listp == 0)
159 return;
160 free_list ((rtx *)listp, &unused_insn_list);
161 }
162
163 /* Make a copy of the INSN_LIST list LINK and return it. */
164 rtx_insn_list *
copy_INSN_LIST(rtx_insn_list * link)165 copy_INSN_LIST (rtx_insn_list *link)
166 {
167 rtx_insn_list *new_queue;
168 rtx_insn_list **pqueue = &new_queue;
169
170 for (; link; link = link->next ())
171 {
172 rtx_insn *x = link->insn ();
173 rtx_insn_list *newlink = alloc_INSN_LIST (x, NULL);
174 *pqueue = newlink;
175 pqueue = (rtx_insn_list **)&XEXP (newlink, 1);
176 }
177 *pqueue = NULL;
178 return new_queue;
179 }
180
181 /* Duplicate the INSN_LIST elements of COPY and prepend them to OLD. */
182 rtx_insn_list *
concat_INSN_LIST(rtx_insn_list * copy,rtx_insn_list * old)183 concat_INSN_LIST (rtx_insn_list *copy, rtx_insn_list *old)
184 {
185 rtx_insn_list *new_rtx = old;
186 for (; copy ; copy = copy->next ())
187 {
188 new_rtx = alloc_INSN_LIST (copy->insn (), new_rtx);
189 PUT_REG_NOTE_KIND (new_rtx, REG_NOTE_KIND (copy));
190 }
191 return new_rtx;
192 }
193
194 /* This function will free up an individual EXPR_LIST node. */
195 void
free_EXPR_LIST_node(rtx ptr)196 free_EXPR_LIST_node (rtx ptr)
197 {
198 XEXP (ptr, 1) = unused_expr_list;
199 unused_expr_list = ptr;
200 }
201
202 /* This function will free up an individual INSN_LIST node. */
203 void
free_INSN_LIST_node(rtx ptr)204 free_INSN_LIST_node (rtx ptr)
205 {
206 gcc_assert (GET_CODE (ptr) == INSN_LIST);
207 XEXP (ptr, 1) = unused_insn_list;
208 unused_insn_list = ptr;
209 }
210
211 /* Remove and free corresponding to ELEM node in the INSN_LIST pointed to
212 by LISTP. */
213 void
remove_free_INSN_LIST_elem(rtx_insn * elem,rtx_insn_list ** listp)214 remove_free_INSN_LIST_elem (rtx_insn *elem, rtx_insn_list **listp)
215 {
216 free_INSN_LIST_node (remove_list_elem (elem, (rtx *)listp));
217 }
218
219 /* Remove and free the first node in the INSN_LIST pointed to by LISTP. */
220 rtx_insn *
remove_free_INSN_LIST_node(rtx_insn_list ** listp)221 remove_free_INSN_LIST_node (rtx_insn_list **listp)
222 {
223 rtx_insn_list *node = *listp;
224 rtx_insn *elem = node->insn ();
225
226 remove_list_node ((rtx *)listp);
227 free_INSN_LIST_node (node);
228
229 return elem;
230 }
231
232 /* Remove and free the first node in the EXPR_LIST pointed to by LISTP. */
233 rtx
remove_free_EXPR_LIST_node(rtx_expr_list ** listp)234 remove_free_EXPR_LIST_node (rtx_expr_list **listp)
235 {
236 rtx_expr_list *node = *listp;
237 rtx elem = XEXP (node, 0);
238
239 remove_list_node ((rtx *)listp);
240 free_EXPR_LIST_node (node);
241
242 return elem;
243 }
244
245 #include "gt-lists.h"
246