2 * Copyright (C) 1995-2011 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
39 #include "beloopana.h"
42 DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
44 #define HASH_LOOP_INFO(info) (hash_ptr((info)->loop) ^ hash_ptr((info)->cls))
46 typedef struct be_loop_info_t {
48 const arch_register_class_t *cls;
49 unsigned max_pressure;
57 static int cmp_loop_info(const void *a, const void *b, size_t size)
59 const be_loop_info_t *i1 = (const be_loop_info_t*)a;
60 const be_loop_info_t *i2 = (const be_loop_info_t*)b;
63 return ! (i1->loop == i2->loop && i1->cls == i2->cls);
67 * Compute the highest register pressure in a block.
68 * @param irg The graph.
69 * @param block The block to compute pressure for.
70 * @param cls The register class to compute pressure for.
71 * @return The highest register pressure in the given block.
73 static unsigned be_compute_block_pressure(const ir_graph *irg,
75 const arch_register_class_t *cls)
77 be_lv_t *lv = be_get_irg_liveness(irg);
78 ir_nodeset_t live_nodes;
81 DBG((dbg, LEVEL_1, "Processing Block %+F\n", block));
83 /* determine largest pressure with this block */
84 ir_nodeset_init(&live_nodes);
85 be_liveness_end_of_block(lv, cls, block, &live_nodes);
86 max_live = ir_nodeset_size(&live_nodes);
88 sched_foreach_reverse(block, irn) {
94 be_liveness_transfer(cls, irn, &live_nodes);
95 cnt = ir_nodeset_size(&live_nodes);
96 max_live = MAX(cnt, max_live);
99 DBG((dbg, LEVEL_1, "Finished with Block %+F (%s %zu)\n", block, cls->name, max_live));
101 ir_nodeset_destroy(&live_nodes);
106 * Compute the highest register pressure in a loop and its sub-loops.
107 * @param loop_ana The loop ana object.
108 * @param loop The loop to compute pressure for.
109 * @param cls The register class to compute pressure for.
110 * @return The highest register pressure in the given loop.
112 static unsigned be_compute_loop_pressure(be_loopana_t *loop_ana, ir_loop *loop,
113 const arch_register_class_t *cls)
117 be_loop_info_t *entry, key;
119 DBG((dbg, LEVEL_1, "\nProcessing Loop %ld\n", loop->loop_nr));
120 assert(get_loop_n_elements(loop) > 0);
123 /* determine maximal pressure in all loop elements */
124 for (i = 0, max = get_loop_n_elements(loop); i < max; ++i) {
125 unsigned son_pressure;
126 loop_element elem = get_loop_element(loop, i);
128 if (*elem.kind == k_ir_node)
129 son_pressure = be_compute_block_pressure(loop_ana->irg, elem.node, cls);
131 assert(*elem.kind == k_ir_loop);
132 son_pressure = be_compute_loop_pressure(loop_ana, elem.son, cls);
135 pressure = MAX(pressure, son_pressure);
137 DBG((dbg, LEVEL_1, "Done with loop %ld, pressure %u for class %s\n", loop->loop_nr, pressure, cls->name));
139 /* update info in set */
142 key.max_pressure = 0;
143 entry = set_insert(be_loop_info_t, loop_ana->data, &key, sizeof(key), HASH_LOOP_INFO(&key));
144 entry->max_pressure = MAX(entry->max_pressure, pressure);
150 * Compute the register pressure for a class of all loops in a graph
151 * @param irg The graph
152 * @param cls The register class to compute the pressure for
153 * @return The loop analysis object.
155 be_loopana_t *be_new_loop_pressure_cls(ir_graph *irg,
156 const arch_register_class_t *cls)
158 be_loopana_t *loop_ana = XMALLOC(be_loopana_t);
160 loop_ana->data = new_set(cmp_loop_info, 16);
163 DBG((dbg, LEVEL_1, "\n=====================================================\n", cls->name));
164 DBG((dbg, LEVEL_1, " Computing register pressure for class %s:\n", cls->name));
165 DBG((dbg, LEVEL_1, "=====================================================\n", cls->name));
167 assure_loopinfo(irg);
169 be_compute_loop_pressure(loop_ana, get_irg_loop(irg), cls);
175 * Compute the register pressure for all classes of all loops in the irg.
176 * @param irg The graph
177 * @return The loop analysis object.
179 be_loopana_t *be_new_loop_pressure(ir_graph *irg,
180 const arch_register_class_t *cls)
182 be_loopana_t *loop_ana = XMALLOC(be_loopana_t);
183 ir_loop *irg_loop = get_irg_loop(irg);
184 const arch_env_t *arch_env = be_get_irg_arch_env(irg);
187 loop_ana->data = new_set(cmp_loop_info, 16);
190 assure_loopinfo(irg);
193 be_compute_loop_pressure(loop_ana, irg_loop, cls);
195 for (i = arch_env->n_register_classes - 1; i >= 0; --i) {
196 const arch_register_class_t *cls = &arch_env->register_classes[i];
197 DBG((dbg, LEVEL_1, "\n=====================================================\n", cls->name));
198 DBG((dbg, LEVEL_1, " Computing register pressure for class %s:\n", cls->name));
199 DBG((dbg, LEVEL_1, "=====================================================\n", cls->name));
200 be_compute_loop_pressure(loop_ana, irg_loop, cls);
208 * Returns the computed register pressure for the given class and loop.
209 * @return The pressure or INT_MAX if not found
211 unsigned be_get_loop_pressure(be_loopana_t *loop_ana, const arch_register_class_t *cls, ir_loop *loop)
213 unsigned pressure = INT_MAX;
214 be_loop_info_t *entry, key;
220 entry = set_find(be_loop_info_t, loop_ana->data, &key, sizeof(key), HASH_LOOP_INFO(&key));
223 pressure = entry->max_pressure;
225 panic("Pressure not computed for given class and loop object.");
231 * Frees the loop analysis object.
233 void be_free_loop_pressure(be_loopana_t *loop_ana)
235 del_set(loop_ana->data);
239 BE_REGISTER_MODULE_CONSTRUCTOR(be_init_loopana)
240 void be_init_loopana(void)
242 FIRM_DBG_REGISTER(dbg, "firm.be.loopana");