2 * Copyright (C) 1995-2007 University of Karlsruhe. All right reserved.
4 * This file is part of libFirm.
6 * This file may be distributed and/or modified under the terms of the
7 * GNU General Public License version 2 as published by the Free Software
8 * Foundation and appearing in the file LICENSE.GPL included in the
9 * packaging of this file.
11 * Licensees holding valid libFirm Professional Edition licenses may use
12 * this file in accordance with the libFirm Commercial License.
13 * Agreement provided with the Software.
15 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
16 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * @brief modifies schedule so flags dependencies are respected.
23 * @author Matthias Braun, Christoph Mallon
24 * @version $Id: besched.h 14693 2007-06-21 15:35:49Z beck $
34 #include "iredges_t.h"
41 #include "besched_t.h"
43 static const arch_env_t *arch_env = NULL;
44 static const arch_register_class_t *flag_class = NULL;
45 static const arch_register_t *flags_reg = NULL;
46 static func_rematerialize remat = NULL;
48 static ir_node *default_remat(ir_node *node, ir_node *after)
50 ir_node *copy = exact_copy(node);
51 sched_add_after(after, copy);
57 * tests wether we can legally move node node after node after
58 * (only works for nodes in same block)
60 static int can_move(ir_node *node, ir_node *after)
62 const ir_edge_t *edge;
63 assert(get_nodes_block(node) == get_nodes_block(after));
65 /* TODO respect dep edges */
66 assert(get_irn_n_edges_kind(node, EDGE_KIND_DEP) == 0);
68 /** all users have to be after the after node */
69 foreach_out_edge(node, edge) {
70 ir_node *out = get_edge_src_irn(edge);
72 const ir_edge_t *edge2;
73 assert(get_irn_n_edges_kind(out, EDGE_KIND_DEP) == 0);
74 foreach_out_edge(out, edge2) {
75 ir_node *out2 = get_edge_src_irn(edge2);
76 /* phi represents a usage at block end */
79 if(sched_get_time_step(out2) <= sched_get_time_step(after)) {
84 /* phi represents a usage at block end */
87 if(sched_get_time_step(out) <= sched_get_time_step(after)) {
93 ir_fprintf(stderr, "Can move node %+F after node %+F\n", node, after);
97 static void rematerialize_or_move(ir_node *flags_needed, ir_node *node,
98 ir_node *flag_consumers, int pn)
104 if(can_move(flags_needed, node)) {
106 sched_remove(flags_needed);
107 sched_add_after(node, flags_needed);
111 copy = remat(flags_needed, node);
113 if(get_irn_mode(copy) == mode_T) {
114 ir_node *block = get_nodes_block(copy);
115 ir_mode *mode = flag_class->mode;
116 value = new_rd_Proj(NULL, current_ir_graph, block,
125 int arity = get_irn_arity(n);
126 for(i = 0; i < arity; ++i) {
127 ir_node *in = get_irn_n(n, i);
129 if(in == flags_needed) {
130 set_irn_n(n, i, value);
138 static void fix_flags_walker(ir_node *block, void *env)
141 ir_node *flags_needed = NULL;
142 ir_node *flag_consumers = NULL;
146 sched_foreach_reverse(block, node) {
148 ir_node *new_flags_needed = NULL;
150 if(node == flags_needed) {
153 flag_consumers = NULL;
156 /* test wether node destroys the flags */
157 if(flags_needed != NULL && arch_irn_is(arch_env, node, modify_flags)) {
159 rematerialize_or_move(flags_needed, node, flag_consumers, pn);
161 flag_consumers = NULL;
164 /* test wether the current node needs flags */
165 arity = get_irn_arity(node);
166 for(i = 0; i < arity; ++i) {
167 //ir_node *in = get_irn_n(node, i);
168 const arch_register_class_t *cls
169 = arch_get_irn_reg_class(arch_env, node, i);
170 if(cls == flag_class) {
171 assert(new_flags_needed == NULL);
172 new_flags_needed = get_irn_n(node, i);
176 if(new_flags_needed == NULL)
179 if(new_flags_needed != flags_needed) {
180 if(flags_needed != NULL) {
181 /* rematerialize node */
182 rematerialize_or_move(flags_needed, node, flag_consumers, pn);
184 flag_consumers = NULL;
187 if(get_nodes_block(new_flags_needed) != block) {
188 panic("remat across blocks not implemented yet");
190 flag_consumers = NULL;
192 flags_needed = new_flags_needed;
193 arch_set_irn_register(arch_env, flags_needed, flags_reg);
194 if(is_Proj(flags_needed)) {
195 pn = get_Proj_proj(flags_needed);
196 flags_needed = get_Proj_pred(flags_needed);
198 flag_consumers = node;
199 set_irn_link(flag_consumers, NULL);
200 assert(arch_irn_is(arch_env, flags_needed, rematerializable));
203 /* link all consumers in a list */
204 set_irn_link(flag_consumers, node);
205 flag_consumers = node;
209 assert(flags_needed == NULL);
210 assert(flag_consumers == NULL);
213 void be_sched_fix_flags(be_irg_t *birg, const arch_register_class_t *flag_cls,
214 func_rematerialize remat_func)
216 ir_graph *irg = be_get_birg_irg(birg);
218 arch_env = be_get_birg_arch_env(birg);
219 flag_class = flag_cls;
220 flags_reg = & flag_class->regs[0];
223 remat = &default_remat;
225 set_using_irn_link(irg);
226 irg_block_walk_graph(irg, fix_flags_walker, NULL, NULL);
227 clear_using_irn_link(irg);