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 Compute register pressure in loops.
23 * @author Christian Wuerdig
42 #include "beloopana.h"
45 DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL);
47 #define HASH_LOOP_INFO(info) (HASH_PTR((info)->loop) ^ HASH_PTR((info)->cls))
49 typedef struct _be_loop_info_t {
51 const arch_register_class_t *cls;
52 unsigned max_pressure;
55 struct _be_loopana_t {
60 static int cmp_loop_info(const void *a, const void *b, size_t sz) {
61 const be_loop_info_t *i1 = a;
62 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 loop_ana The loop ana object.
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(be_loopana_t *loop_ana, ir_node *block, const arch_register_class_t *cls) {
75 const be_irg_t *birg = loop_ana->birg;
76 const arch_env_t *aenv = be_get_birg_arch_env(birg);
77 be_lv_t *lv = be_get_birg_liveness(birg);
78 pset *live_nodes = pset_new_ptr_default();
82 DBG((dbg, LEVEL_1, "Processing Block %+F\n", block));
84 /* determine largest pressure with this block */
85 live_nodes = be_liveness_end_of_block(lv, aenv, cls, block, live_nodes);
86 max_live = pset_count(live_nodes);
88 sched_foreach_reverse(block, irn) {
94 live_nodes = be_liveness_transfer(aenv, cls, irn, live_nodes);
95 cnt = pset_count(live_nodes);
96 max_live = MAX(cnt, max_live);
99 DBG((dbg, LEVEL_1, "Finished with Block %+F (%s %u)\n", block, cls->name, max_live));
101 del_pset(live_nodes);
106 * Compute the highest register pressure in a loop and it's 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, const arch_register_class_t *cls) {
115 be_loop_info_t *entry, key;
117 DBG((dbg, LEVEL_1, "\nProcessing Loop %d\n", loop->loop_nr));
118 assert(get_loop_n_elements(loop) > 0);
121 /* determine maximal pressure in all loop elements */
122 for (i = 0, max = get_loop_n_elements(loop); i < max; ++i) {
123 unsigned son_pressure;
124 loop_element elem = get_loop_element(loop, i);
126 switch (*elem.kind) {
128 son_pressure = be_compute_block_pressure(loop_ana, elem.node, cls);
131 son_pressure = be_compute_loop_pressure(loop_ana, elem.son, cls);
134 panic("Unknown element found in loop");
138 pressure = MAX(pressure, son_pressure);
140 DBG((dbg, LEVEL_1, "Done with loop %d, pressure %u for class %s\n", loop->loop_nr, pressure, cls->name));
142 /* update info in set */
145 key.max_pressure = 0;
146 entry = set_insert(loop_ana->data, &key, sizeof(key), HASH_LOOP_INFO(&key));
147 entry->max_pressure = MAX(entry->max_pressure, pressure);
153 * Compute the register pressure for a class of all loops in the birg.
154 * @param birg The backend irg object
155 * @param cls The register class to compute the pressure for
156 * @return The loop analysis object.
158 be_loopana_t *be_new_loop_pressure_cls(be_irg_t *birg,
159 const arch_register_class_t *cls) {
160 ir_graph *irg = be_get_birg_irg(birg);
161 be_loopana_t *loop_ana = xmalloc(sizeof(*loop_ana));
163 loop_ana->data = new_set(cmp_loop_info, 16);
164 loop_ana->birg = birg;
166 DBG((dbg, LEVEL_1, "\n=====================================================\n", cls->name));
167 DBG((dbg, LEVEL_1, " Computing register pressure for class %s:\n", cls->name));
168 DBG((dbg, LEVEL_1, "=====================================================\n", cls->name));
170 be_compute_loop_pressure(loop_ana, get_irg_loop(irg), cls);
176 * Compute the register pressure for all classes of all loops in the birg.
177 * @param birg The backend irg object
178 * @return The loop analysis object.
180 be_loopana_t *be_new_loop_pressure(be_irg_t *birg) {
181 ir_graph *irg = be_get_birg_irg(birg);
182 be_loopana_t *loop_ana = xmalloc(sizeof(*loop_ana));
183 ir_loop *irg_loop = get_irg_loop(irg);
184 const arch_env_t *arch_env = be_get_birg_arch_env(birg);
185 const arch_isa_t *isa = arch_env->isa;
188 loop_ana->data = new_set(cmp_loop_info, 16);
189 loop_ana->birg = birg;
191 for (i = arch_isa_get_n_reg_class(isa) - 1; i >= 0; --i) {
192 const arch_register_class_t *cls = arch_isa_get_reg_class(isa, i);
193 DBG((dbg, LEVEL_1, "\n=====================================================\n", cls->name));
194 DBG((dbg, LEVEL_1, " Computing register pressure for class %s:\n", cls->name));
195 DBG((dbg, LEVEL_1, "=====================================================\n", cls->name));
196 be_compute_loop_pressure(loop_ana, irg_loop, cls);
203 * Returns the computed register pressure for the given class and loop.
204 * @return The pressure or INT_MAX if not found
206 unsigned be_get_loop_pressure(be_loopana_t *loop_ana, const arch_register_class_t *cls, ir_loop *loop) {
207 unsigned pressure = INT_MAX;
208 be_loop_info_t *entry, key;
214 entry = set_find(loop_ana->data, &key, sizeof(key), HASH_LOOP_INFO(&key));
217 pressure = entry->max_pressure;
219 assert(0 && "Pressure not computed for given class and loop object.");
225 * Frees the loop analysis object.
227 void be_free_loop_pressure(be_loopana_t *loop_ana) {
228 del_set(loop_ana->data);
232 void be_init_loopana(void)
234 FIRM_DBG_REGISTER(dbg, "firm.be.loopana");
237 BE_REGISTER_MODULE_CONSTRUCTOR(be_init_loopana);