2 * linear-scan.c: linbear scan register allocation
5 * Dietmar Maurer (dietmar@ximian.com)
6 * Miguel de Icaza (miguel@ximian.com)
8 * (C) 2001 Ximian, Inc.
17 //#define MNAME "nest_test"
20 #define DEGUG_LIVENESS
25 mono_bitset_mp_new (MonoMemPool *mp, guint32 max_size)
27 int size = mono_bitset_alloc_size (max_size, 0);
30 mem = mono_mempool_alloc0 (mp, size);
31 return mono_bitset_mem_new (mem, max_size, MONO_BITSET_DONT_FREE);
35 mono_bitset_print (MonoBitSet *set)
40 for (i = 0; i < mono_bitset_size (set); i++) {
42 if (mono_bitset_test (set, i))
50 mono_update_live_range (MonoFlowGraph *cfg, int varnum, int block_num, int tree_pos)
52 MonoVarInfo *vi = &g_array_index (cfg->varinfo, MonoVarInfo, varnum);
53 guint32 abs_pos = (block_num << 16) | tree_pos;
55 if (vi->range.first_use.abs_pos > abs_pos)
56 vi->range.first_use.abs_pos = abs_pos;
58 if (vi->range.last_use.abs_pos < abs_pos)
59 vi->range.last_use.abs_pos = abs_pos;
63 mono_update_live_info (MonoFlowGraph *cfg)
67 for (i = 0; i < cfg->block_count; i++) {
68 MonoBBlock *bb = &cfg->bblocks [i];
70 for (j = cfg->varinfo->len - 1; j > 0; j--) {
72 if (mono_bitset_test (bb->live_in_set, j))
73 mono_update_live_range (cfg, j, bb->num, 0);
75 if (mono_bitset_test (bb->live_out_set, j))
76 mono_update_live_range (cfg, j, bb->num, bb->forest->len);
82 mono_update_gen_set (MonoFlowGraph *cfg, MonoBBlock *bb, MBTree *tree,
83 int tnum, MonoBitSet *set)
87 case MB_TERM_REMOTE_STIND_I1:
88 case MB_TERM_REMOTE_STIND_I2:
89 case MB_TERM_REMOTE_STIND_I4:
90 case MB_TERM_REMOTE_STIND_I8:
91 case MB_TERM_REMOTE_STIND_R4:
92 case MB_TERM_REMOTE_STIND_R8:
93 case MB_TERM_REMOTE_STIND_OBJ:
94 case MB_TERM_STIND_I1:
95 case MB_TERM_STIND_I2:
96 case MB_TERM_STIND_I4:
97 case MB_TERM_STIND_I8:
98 case MB_TERM_STIND_R4:
99 case MB_TERM_STIND_R8:
100 case MB_TERM_STIND_OBJ:
101 if (tree->left->op != MB_TERM_ADDR_L)
102 mono_update_gen_set (cfg, bb, tree->left, tnum, set);
104 mono_update_live_range (cfg, tree->left->data.i,
108 mono_update_gen_set (cfg, bb, tree->left, tnum, set);
114 mono_update_gen_set (cfg, bb, tree->right, tnum, set);
116 if (tree->op == MB_TERM_ADDR_L) {
117 mono_update_live_range (cfg, tree->data.i, bb->num, tnum);
118 mono_bitset_set (set, tree->data.i);
123 mono_analyze_liveness (MonoFlowGraph *cfg)
125 MonoBitSet *old_live_in_set, *old_live_out_set;
128 int i, j , max_vars = cfg->varinfo->len;
130 #ifdef DEGUG_LIVENESS
131 int debug = !strcmp (cfg->method->name, MNAME);
133 printf ("LIVENLESS %s.%s:%s\n", cfg->method->klass->name_space,
134 cfg->method->klass->name, cfg->method->name);
137 old_live_in_set = mono_bitset_new (max_vars, 0);
138 old_live_out_set = mono_bitset_new (max_vars, 0);
140 for (i = 0; i < cfg->block_count; i++) {
141 MonoBBlock *bb = &cfg->bblocks [i];
143 bb->gen_set = mono_bitset_mp_new (cfg->mp, max_vars);
144 bb->kill_set = mono_bitset_mp_new (cfg->mp, max_vars);
145 bb->live_in_set = mono_bitset_mp_new (cfg->mp, max_vars);
146 bb->live_out_set = mono_bitset_mp_new (cfg->mp, max_vars);
148 for (j = 0; j < bb->forest->len; j++) {
149 MBTree *t1 = (MBTree *) g_ptr_array_index (bb->forest, j);
151 mono_bitset_clear_all (old_live_in_set);
152 mono_update_gen_set (cfg, bb, t1, j, old_live_in_set);
153 mono_bitset_sub (old_live_in_set, bb->kill_set);
154 mono_bitset_union (bb->gen_set, old_live_in_set);
157 case MB_TERM_REMOTE_STIND_I1:
158 case MB_TERM_REMOTE_STIND_I2:
159 case MB_TERM_REMOTE_STIND_I4:
160 case MB_TERM_REMOTE_STIND_I8:
161 case MB_TERM_REMOTE_STIND_R4:
162 case MB_TERM_REMOTE_STIND_R8:
163 case MB_TERM_REMOTE_STIND_OBJ:
164 case MB_TERM_STIND_I1:
165 case MB_TERM_STIND_I2:
166 case MB_TERM_STIND_I4:
167 case MB_TERM_STIND_I8:
168 case MB_TERM_STIND_R4:
169 case MB_TERM_STIND_R8:
170 case MB_TERM_STIND_OBJ:
171 if (t1->left->op == MB_TERM_ADDR_L)
172 mono_bitset_set (bb->kill_set, t1->left->data.i);
177 #ifdef DEGUG_LIVENESS
179 printf ("BLOCK %d (", bb->num);
180 for (l = bb->succ; l; l = l->next) {
181 MonoBBlock *t = (MonoBBlock *)l->data;
182 printf ("%d, ", t->num);
185 printf ("GEN %d: ", i); mono_bitset_print (bb->gen_set); printf ("\n");
186 printf ("KILL %d: ", i); mono_bitset_print (bb->kill_set); printf ("\n");
194 for (i = cfg->block_count - 1; i >= 0; i--) {
195 MonoBBlock *bb = &cfg->bblocks [i];
197 mono_bitset_copyto (bb->live_in_set, old_live_in_set);
198 mono_bitset_copyto (bb->live_out_set, old_live_out_set);
200 mono_bitset_copyto (bb->live_out_set, bb->live_in_set);
201 mono_bitset_sub (bb->live_in_set, bb->kill_set);
202 mono_bitset_union (bb->live_in_set, bb->gen_set);
204 mono_bitset_clear_all (bb->live_out_set);
206 for (l = bb->succ; l; l = l->next) {
207 MonoBBlock *t = (MonoBBlock *)l->data;
208 mono_bitset_union (bb->live_out_set, t->live_in_set);
211 if (!(mono_bitset_equal (old_live_in_set, bb->live_in_set) &&
212 mono_bitset_equal (old_live_out_set, bb->live_out_set)))
218 mono_bitset_free (old_live_in_set);
219 mono_bitset_free (old_live_out_set);
222 #ifdef DEGUG_LIVENESS
224 for (i = 0; i < cfg->block_count; i++) {
225 MonoBBlock *bb = &cfg->bblocks [i];
227 printf ("LIVE IN %d: ", i);
228 mono_bitset_print (bb->live_in_set);
230 printf ("LIVE OUT %d: ", i);
231 mono_bitset_print (bb->live_out_set);
239 mono_varlist_insert_sorted (GList *list, MonoVarInfo *vi, gboolean sort_end)
244 return g_list_prepend (NULL, vi);
246 for (l = list; l; l = l->next) {
247 MonoVarInfo *v = (MonoVarInfo *)l->data;
250 if (vi->range.last_use.abs_pos <= v->range.last_use.abs_pos) {
251 list = g_list_insert_before (list, l, vi);
255 if (vi->range.first_use.abs_pos <= v->range.first_use.abs_pos) {
256 list = g_list_insert_before (list, l, vi);
262 list = g_list_append (list, vi);
268 mono_linear_scan (MonoFlowGraph *cfg, guint32 *used_mask)
270 GList *l, *ranges = NULL;
271 GList *active = NULL;
276 MonoMethod *m = cfg->method;
277 int debug = !strcmp (cfg->method->name, MNAME);
280 printf ("VARINFO for %s.%s:%s\n", m->klass->name_space, m->klass->name, m->name);
283 mono_analyze_liveness (cfg);
284 mono_update_live_info (cfg);
286 for (i = 1; i < cfg->varinfo->len; i++) {
287 MonoVarInfo *vi = &g_array_index (cfg->varinfo, MonoVarInfo, i);
290 if (vi->range.first_use.abs_pos > vi->range.last_use.abs_pos)
293 /* we can only allocate 32 bit values */
294 if (vi->isvolatile || (vi->type != VAL_I32 && vi->type != VAL_POINTER))
297 ranges = mono_varlist_insert_sorted (ranges, vi, FALSE);
303 for (l = ranges; l; l = l->next) {
304 MonoVarInfo *vi = (MonoVarInfo *)l->data;
306 printf ("VAR %d %08x %08x\n", vi->varnum, vi->range.first_use.abs_pos,
307 vi->range.last_use.abs_pos);
312 /* we can use 2 registers for global allocation */
313 regs = g_list_prepend (regs, (gpointer)X86_EBX);
314 regs = g_list_prepend (regs, (gpointer)X86_ESI);
316 max_regs = g_list_length (regs);
320 for (l = ranges; l; l = l->next) {
321 MonoVarInfo *vi = (MonoVarInfo *)l->data;
325 printf ("START %2d %08x %08x\n", vi->varnum, vi->range.first_use.abs_pos,
326 vi->range.last_use.abs_pos);
328 /* expire old intervals in active */
330 MonoVarInfo *v = (MonoVarInfo *)active->data;
332 if (v->range.last_use.abs_pos >= vi->range.first_use.abs_pos)
337 printf ("EXPIR %2d %08x %08x\n", v->varnum,
338 v->range.first_use.abs_pos, v->range.last_use.abs_pos);
340 active = g_list_remove_link (active, active);
341 regs = g_list_prepend (regs, (gpointer)v->reg);
344 if (active && g_list_length (active) == max_regs) {
347 GList *a = g_list_nth (active, max_regs - 1);
348 MonoVarInfo *v = (MonoVarInfo *)a->data;
350 if (v->range.last_use.abs_pos > vi->range.last_use.abs_pos) {
353 active = g_list_remove_link (active, a);
354 active = mono_varlist_insert_sorted (active, vi, TRUE);
357 printf ("SPILL0 %2d %08x %08x\n", v->varnum,
358 v->range.first_use.abs_pos, v->range.last_use.abs_pos);
363 printf ("SPILL1 %2d %08x %08x\n", vi->varnum,
364 vi->range.first_use.abs_pos, vi->range.last_use.abs_pos);
369 /* assign register */
373 vi->reg = (int)regs->data;
375 *used_mask |= 1 << vi->reg;
377 regs = g_list_remove_link (regs, regs);
381 printf ("ADD %2d %08x %08x\n", vi->varnum,
382 vi->range.first_use.abs_pos, vi->range.last_use.abs_pos);
384 active = mono_varlist_insert_sorted (active, vi, TRUE);
391 for (a = active; a; a = a->next) {
392 MonoVarInfo *v = (MonoVarInfo *)a->data;
394 printf ("ACT %2d %08x %08x %d\n", v->varnum,
395 v->range.first_use.abs_pos, v->range.last_use.abs_pos, v->reg);
403 g_list_free (active);
404 g_list_free (ranges);