2 * Copyright (C) 1995-2008 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 Compute register pressure in loops.
23 * @author Christian Wuerdig
40 #include "beloopana.h"
43 DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL);
45 #define HASH_LOOP_INFO(info) (HASH_PTR((info)->loop) ^ HASH_PTR((info)->cls))
47 typedef struct be_loop_info_t {
49 const arch_register_class_t *cls;
50 unsigned max_pressure;
58 static int cmp_loop_info(const void *a, const void *b, size_t size)
60 const be_loop_info_t *i1 = a;
61 const be_loop_info_t *i2 = b;
64 return ! (i1->loop == i2->loop && i1->cls == i2->cls);
68 * Compute the highest register pressure in a block.
69 * @param irg The graph.
70 * @param block The block to compute pressure for.
71 * @param cls The register class to compute pressure for.
72 * @return The highest register pressure in the given block.
74 static unsigned be_compute_block_pressure(const ir_graph *irg,
76 const arch_register_class_t *cls)
78 be_lv_t *lv = be_get_irg_liveness(irg);
79 ir_nodeset_t live_nodes;
83 DBG((dbg, LEVEL_1, "Processing Block %+F\n", block));
85 /* determine largest pressure with this block */
86 ir_nodeset_init(&live_nodes);
87 be_liveness_end_of_block(lv, cls, block, &live_nodes);
88 max_live = ir_nodeset_size(&live_nodes);
90 sched_foreach_reverse(block, irn) {
96 be_liveness_transfer(cls, irn, &live_nodes);
97 cnt = ir_nodeset_size(&live_nodes);
98 max_live = MAX(cnt, max_live);
101 DBG((dbg, LEVEL_1, "Finished with Block %+F (%s %u)\n", block, cls->name, max_live));
103 ir_nodeset_destroy(&live_nodes);
108 * Compute the highest register pressure in a loop and it's sub-loops.
109 * @param loop_ana The loop ana object.
110 * @param loop The loop to compute pressure for.
111 * @param cls The register class to compute pressure for.
112 * @return The highest register pressure in the given loop.
114 static unsigned be_compute_loop_pressure(be_loopana_t *loop_ana, ir_loop *loop,
115 const arch_register_class_t *cls)
119 be_loop_info_t *entry, key;
121 DBG((dbg, LEVEL_1, "\nProcessing Loop %d\n", loop->loop_nr));
122 assert(get_loop_n_elements(loop) > 0);
125 /* determine maximal pressure in all loop elements */
126 for (i = 0, max = get_loop_n_elements(loop); i < max; ++i) {
127 unsigned son_pressure;
128 loop_element elem = get_loop_element(loop, i);
130 if (*elem.kind == k_ir_node)
131 son_pressure = be_compute_block_pressure(loop_ana->irg, elem.node, cls);
133 assert(*elem.kind == k_ir_loop);
134 son_pressure = be_compute_loop_pressure(loop_ana, elem.son, cls);
137 pressure = MAX(pressure, son_pressure);
139 DBG((dbg, LEVEL_1, "Done with loop %d, pressure %u for class %s\n", loop->loop_nr, pressure, cls->name));
141 /* update info in set */
144 key.max_pressure = 0;
145 entry = set_insert(loop_ana->data, &key, sizeof(key), HASH_LOOP_INFO(&key));
146 entry->max_pressure = MAX(entry->max_pressure, pressure);
152 * Compute the register pressure for a class of all loops in a graph
153 * @param irg The graph
154 * @param cls The register class to compute the pressure for
155 * @return The loop analysis object.
157 be_loopana_t *be_new_loop_pressure_cls(ir_graph *irg,
158 const arch_register_class_t *cls)
160 be_loopana_t *loop_ana = XMALLOC(be_loopana_t);
162 loop_ana->data = new_set(cmp_loop_info, 16);
165 DBG((dbg, LEVEL_1, "\n=====================================================\n", cls->name));
166 DBG((dbg, LEVEL_1, " Computing register pressure for class %s:\n", cls->name));
167 DBG((dbg, LEVEL_1, "=====================================================\n", cls->name));
169 /* construct control flow loop tree */
170 if (! (get_irg_loopinfo_state(irg) & loopinfo_cf_consistent)) {
171 construct_cf_backedges(irg);
174 be_compute_loop_pressure(loop_ana, get_irg_loop(irg), cls);
180 * Compute the register pressure for all classes of all loops in the irg.
181 * @param irg The graph
182 * @return The loop analysis object.
184 be_loopana_t *be_new_loop_pressure(ir_graph *irg,
185 const arch_register_class_t *cls)
187 be_loopana_t *loop_ana = XMALLOC(be_loopana_t);
188 ir_loop *irg_loop = get_irg_loop(irg);
189 const arch_env_t *arch_env = be_get_irg_arch_env(irg);
192 loop_ana->data = new_set(cmp_loop_info, 16);
195 /* construct control flow loop tree */
196 if (! (get_irg_loopinfo_state(irg) & loopinfo_cf_consistent)) {
197 construct_cf_backedges(irg);
201 be_compute_loop_pressure(loop_ana, irg_loop, cls);
203 for (i = arch_env_get_n_reg_class(arch_env) - 1; i >= 0; --i) {
204 const arch_register_class_t *cls = arch_env_get_reg_class(arch_env, i);
205 DBG((dbg, LEVEL_1, "\n=====================================================\n", cls->name));
206 DBG((dbg, LEVEL_1, " Computing register pressure for class %s:\n", cls->name));
207 DBG((dbg, LEVEL_1, "=====================================================\n", cls->name));
208 be_compute_loop_pressure(loop_ana, irg_loop, cls);
216 * Returns the computed register pressure for the given class and loop.
217 * @return The pressure or INT_MAX if not found
219 unsigned be_get_loop_pressure(be_loopana_t *loop_ana, const arch_register_class_t *cls, ir_loop *loop)
221 unsigned pressure = INT_MAX;
222 be_loop_info_t *entry, key;
228 entry = set_find(loop_ana->data, &key, sizeof(key), HASH_LOOP_INFO(&key));
231 pressure = entry->max_pressure;
233 panic("Pressure not computed for given class and loop object.");
239 * Frees the loop analysis object.
241 void be_free_loop_pressure(be_loopana_t *loop_ana)
243 del_set(loop_ana->data);
247 BE_REGISTER_MODULE_CONSTRUCTOR(be_init_loopana);
248 void be_init_loopana(void)
250 FIRM_DBG_REGISTER(dbg, "firm.be.loopana");