2 * ssa.c: Static single assign form support for the JIT compiler.
5 * Dietmar Maurer (dietmar@ximian.com)
7 * (C) 2003 Ximian, Inc.
10 #include <mono/metadata/debug-helpers.h>
16 #define USE_ORIGINAL_VARS
17 #define CREATE_PRUNED_SSA
21 #define NEW_PHI(cfg,dest,val) do { \
22 (dest) = mono_mempool_alloc0 ((cfg)->mempool, sizeof (MonoInst)); \
23 (dest)->opcode = OP_PHI; \
24 (dest)->inst_c0 = (val); \
27 #define NEW_ICONST(cfg,dest,val) do { \
28 (dest) = mono_mempool_alloc0 ((cfg)->mempool, sizeof (MonoInst)); \
29 (dest)->opcode = OP_ICONST; \
30 (dest)->inst_c0 = (val); \
31 (dest)->type = STACK_I4; \
36 g_list_prepend_mempool (GList* l, MonoMemPool* mp, gpointer datum)
38 GList* n = mono_mempool_alloc (mp, sizeof (GList));
46 unlink_target (MonoBasicBlock *bb, MonoBasicBlock *target)
50 for (i = 0; i < bb->out_count; i++) {
51 if (bb->out_bb [i] == target) {
52 bb->out_bb [i] = bb->out_bb [--bb->out_count];
56 for (i = 0; i < target->in_count; i++) {
57 if (target->in_bb [i] == bb) {
58 target->in_bb [i] = target->in_bb [--target->in_count];
66 unlink_unused_bblocks (MonoCompile *cfg)
71 g_assert (cfg->comp_done & MONO_COMP_REACHABILITY);
73 for (bb = cfg->bb_entry; bb && bb->next_bb;) {
74 if (!(bb->next_bb->flags & BB_REACHABLE)) {
75 bb->next_bb = bb->next_bb->next_bb;
80 for (i = 1; i < cfg->num_bblocks; i++) {
81 bb = cfg->bblocks [i];
83 if (!(bb->flags & BB_REACHABLE)) {
84 for (j = 0; j < bb->in_count; j++) {
85 unlink_target (bb->in_bb [j], bb);
87 for (j = 0; j < bb->out_count; j++) {
88 unlink_target (bb, bb->out_bb [j]);
98 replace_usage (MonoCompile *cfg, MonoBasicBlock *bb, MonoInst *inst, MonoInst **stack)
105 arity = mono_burg_arity [inst->opcode];
107 if ((inst->ssa_op == MONO_SSA_LOAD || inst->ssa_op == MONO_SSA_ADDRESS_TAKEN) &&
108 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG)) {
110 int idx = inst->inst_i0->inst_c0;
113 new_var = stack [idx];
115 new_var = cfg->varinfo [idx];
117 if ((new_var->opcode != OP_ARG) && (new_var->opcode != OP_LOCAL)) {
118 /* uninitialized variable ? */
119 g_warning ("using uninitialized variables %d in BB%d (%s)", idx, bb->block_num,
120 mono_method_full_name (cfg->method, TRUE));
121 //g_assert_not_reached ();
125 printf ("REPLACE BB%d %d %d\n", bb->block_num, idx, new_var->inst_c0);
127 inst->inst_i0 = new_var;
131 if (inst->ssa_op != MONO_SSA_STORE)
132 replace_usage (cfg, bb, inst->inst_left, stack);
134 replace_usage (cfg, bb, inst->inst_right, stack);
142 extends_live (MonoInst *inst)
149 arity = mono_burg_arity [inst->opcode];
151 if (inst->ssa_op == MONO_SSA_LOAD &&
152 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG)) {
156 if (inst->ssa_op != MONO_SSA_STORE)
157 if (extends_live (inst->inst_left))
160 if (extends_live (inst->inst_right))
169 replace_usage_new (MonoCompile *cfg, MonoInst *inst, int varnum, MonoInst *rep)
176 arity = mono_burg_arity [inst->opcode];
178 if ((inst->ssa_op == MONO_SSA_LOAD) &&
179 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG) &&
180 inst->inst_i0->inst_c0 == varnum && rep->type == inst->type) {
185 if (inst->ssa_op != MONO_SSA_STORE)
186 if (replace_usage_new (cfg, inst->inst_left, varnum, rep))
189 if (replace_usage_new (cfg, inst->inst_right, varnum, rep))
200 mono_ssa_rename_vars (MonoCompile *cfg, int max_vars, MonoBasicBlock *bb, MonoInst **stack)
202 MonoInst *inst, *new_var;
205 MonoInst **new_stack;
208 printf ("RENAME VARS BB%d %s\n", bb->block_num, mono_method_full_name (cfg->method, TRUE));
211 MONO_BB_FOR_EACH_INS (bb, inst) {
212 if (inst->opcode != OP_PHI)
213 replace_usage (cfg, bb, inst, stack);
215 if (inst->ssa_op == MONO_SSA_STORE &&
216 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG)) {
217 idx = inst->inst_i0->inst_c0;
218 g_assert (idx < max_vars);
220 if ((!stack [idx]) && (bb == cfg->bb_init) && (inst->inst_i0->opcode != OP_ARG)) {
221 new_var = cfg->varinfo [idx];
223 new_var = mono_compile_create_var (cfg, inst->inst_i0->inst_vtype, inst->inst_i0->opcode);
224 new_var->flags = inst->inst_i0->flags;
227 printf ("DEF %d %d\n", idx, new_var->inst_c0);
229 inst->inst_i0 = new_var;
231 #ifdef USE_ORIGINAL_VARS
232 MONO_VARINFO (cfg, new_var->inst_c0)->reg = idx;
235 stack [idx] = new_var;
239 for (i = 0; i < bb->out_count; i++) {
240 MonoBasicBlock *n = bb->out_bb [i];
242 for (j = 0; j < n->in_count; j++)
243 if (n->in_bb [j] == bb)
246 MONO_BB_FOR_EACH_INS (n, inst) {
247 if (inst->ssa_op == MONO_SSA_STORE && inst->inst_i1->opcode == OP_PHI) {
248 idx = inst->inst_i1->inst_c0;
250 new_var = stack [idx];
252 new_var = cfg->varinfo [idx];
254 printf ("FOUND PHI %d (%d, %d)\n", idx, j, new_var->inst_c0);
256 inst->inst_i1->inst_phi_args [j + 1] = new_var->inst_c0;
263 new_stack = g_new (MonoInst*, max_vars);
264 for (tmp = bb->dominated; tmp; tmp = tmp->next) {
265 memcpy (new_stack, stack, sizeof (MonoInst *) * max_vars);
266 mono_ssa_rename_vars (cfg, max_vars, (MonoBasicBlock *)tmp->data, new_stack);
273 mono_ssa_compute (MonoCompile *cfg)
277 MonoMethodVar *vinfo = g_new0 (MonoMethodVar, cfg->num_varinfo);
278 MonoInst *inst, *store, **stack;
280 g_assert (!(cfg->comp_done & MONO_COMP_SSA));
282 /* we dont support methods containing exception clauses */
283 g_assert (mono_method_get_header (cfg->method)->num_clauses == 0);
284 g_assert (!cfg->disable_ssa);
286 //printf ("COMPUTS SSA %s %d\n", mono_method_full_name (cfg->method, TRUE), cfg->num_varinfo);
288 #ifdef CREATE_PRUNED_SSA
289 /* we need liveness for pruned SSA */
290 if (!(cfg->comp_done & MONO_COMP_LIVENESS))
291 mono_analyze_liveness (cfg);
294 mono_compile_dominator_info (cfg, MONO_COMP_DOM | MONO_COMP_IDOM | MONO_COMP_DFRONTIER);
296 for (i = 0; i < cfg->num_varinfo; ++i) {
297 vinfo [i].def_in = mono_bitset_new (cfg->num_bblocks, 0);
299 /* implizit reference at start */
300 mono_bitset_set (vinfo [i].def_in, 0);
302 for (i = 0; i < cfg->num_bblocks; ++i) {
303 MONO_BB_FOR_EACH_INS (cfg->bblocks [i], inst) {
304 if (inst->ssa_op == MONO_SSA_STORE) {
305 idx = inst->inst_i0->inst_c0;
306 g_assert (idx < cfg->num_varinfo);
307 mono_bitset_set (vinfo [idx].def_in, i);
312 /* insert phi functions */
313 for (i = 0; i < cfg->num_varinfo; ++i) {
314 set = mono_compile_iterated_dfrontier (cfg, vinfo [i].def_in);
315 vinfo [i].dfrontier = set;
316 mono_bitset_foreach_bit (set, idx, cfg->num_bblocks) {
317 MonoBasicBlock *bb = cfg->bblocks [idx];
319 /* fixme: create pruned SSA? we would need liveness information for that */
321 if (bb == cfg->bb_exit)
324 if ((cfg->comp_done & MONO_COMP_LIVENESS) && !mono_bitset_test_fast (bb->live_in_set, i)) {
325 //printf ("%d is not live in BB%d %s\n", i, bb->block_num, mono_method_full_name (cfg->method, TRUE));
329 NEW_PHI (cfg, inst, i);
331 inst->inst_phi_args = mono_mempool_alloc0 (cfg->mempool, sizeof (int) * (cfg->bblocks [idx]->in_count + 1));
332 inst->inst_phi_args [0] = cfg->bblocks [idx]->in_count;
334 store = mono_mempool_alloc0 ((cfg)->mempool, sizeof (MonoInst));
335 if (!cfg->varinfo [i]->inst_vtype->type)
336 g_assert_not_reached ();
337 store->opcode = mono_type_to_stind (cfg->varinfo [i]->inst_vtype);
338 store->ssa_op = MONO_SSA_STORE;
339 store->inst_i0 = cfg->varinfo [i];
340 store->inst_i1 = inst;
341 store->klass = store->inst_i0->klass;
343 MONO_INST_LIST_ADD (&store->node, &bb->ins_list);
346 printf ("ADD PHI BB%d %s\n", cfg->bblocks [idx]->block_num, mono_method_full_name (cfg->method, TRUE));
352 for (i = 0; i < cfg->num_varinfo; ++i)
353 mono_bitset_free (vinfo [i].def_in);
357 stack = alloca (sizeof (MonoInst *) * cfg->num_varinfo);
359 for (i = 0; i < cfg->num_varinfo; i++)
362 mono_ssa_rename_vars (cfg, cfg->num_varinfo, cfg->bb_entry, stack);
364 cfg->comp_done |= MONO_COMP_SSA;
367 #ifndef USE_ORIGINAL_VARS
369 mono_ssa_get_allocatable_vars (MonoCompile *cfg)
371 GHashTable *type_hash;
372 GPtrArray *varlist_array = g_ptr_array_new ();
375 g_assert (cfg->comp_done & MONO_COMP_LIVENESS);
377 type_hash = g_hash_table_new (NULL, NULL);
379 for (i = 0; i < cfg->num_varinfo; i++) {
380 MonoInst *ins = cfg->varinfo [i];
381 MonoMethodVar *vmv = MONO_VARINFO (cfg, i);
384 if (vmv->range.first_use.abs_pos > vmv->range.last_use.abs_pos)
387 if (ins->flags & (MONO_INST_VOLATILE|MONO_INST_INDIRECT) ||
388 (ins->opcode != OP_LOCAL && ins->opcode != OP_ARG) || vmv->reg != -1)
391 g_assert (ins->inst_vtype);
392 g_assert (vmv->reg == -1);
393 g_assert (i == vmv->idx);
395 if (!(tidx = (int)g_hash_table_lookup (type_hash, ins->inst_vtype))) {
396 GList *vars = g_list_append (NULL, vmv);
397 g_ptr_array_add (varlist_array, vars);
398 g_hash_table_insert (type_hash, ins->inst_vtype, (gpointer)varlist_array->len);
401 g_ptr_array_index (varlist_array, tidx) =
402 mono_varlist_insert_sorted (cfg, g_ptr_array_index (varlist_array, tidx), vmv, FALSE);
406 g_hash_table_destroy (type_hash);
408 return varlist_array;
413 mono_ssa_replace_copies (MonoCompile *cfg, MonoBasicBlock *bb, MonoInst *inst, char *is_live)
420 arity = mono_burg_arity [inst->opcode];
422 if ((inst->ssa_op == MONO_SSA_LOAD || inst->ssa_op == MONO_SSA_ADDRESS_TAKEN || inst->ssa_op == MONO_SSA_STORE) &&
423 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG)) {
425 int idx = inst->inst_i0->inst_c0;
426 MonoMethodVar *mv = MONO_VARINFO (cfg, idx);
428 if (mv->reg != -1 && mv->reg != mv->idx) {
430 is_live [mv->reg] = 1;
432 new_var = cfg->varinfo [mv->reg];
435 printf ("REPLACE COPY BB%d %d %d\n", bb->block_num, idx, new_var->inst_c0);
436 g_assert (cfg->varinfo [mv->reg]->inst_vtype == cfg->varinfo [idx]->inst_vtype);
438 inst->inst_i0 = new_var;
440 is_live [mv->idx] = 1;
446 mono_ssa_replace_copies (cfg, bb, inst->inst_left, is_live);
448 mono_ssa_replace_copies (cfg, bb, inst->inst_right, is_live);
451 if (inst->ssa_op == MONO_SSA_STORE && inst->inst_i1->ssa_op == MONO_SSA_LOAD &&
452 inst->inst_i0->inst_c0 == inst->inst_i1->inst_i0->inst_c0) {
453 inst->ssa_op = MONO_SSA_NOP;
454 inst->opcode = OP_NOP;
460 mono_ssa_remove (MonoCompile *cfg)
462 MonoInst *inst, *phi;
465 #ifndef USE_ORIGINAL_VARS
466 GPtrArray *varlist_array;
469 g_assert (cfg->comp_done & MONO_COMP_SSA);
471 for (i = 0; i < cfg->num_bblocks; ++i) {
472 MonoBasicBlock *bb = cfg->bblocks [i];
473 MONO_BB_FOR_EACH_INS (bb, inst) {
474 if (inst->ssa_op == MONO_SSA_STORE && inst->inst_i1->opcode == OP_PHI) {
477 g_assert (phi->inst_phi_args [0] == bb->in_count);
479 for (j = 0; j < bb->in_count; j++) {
480 MonoBasicBlock *pred = bb->in_bb [j];
481 int idx = phi->inst_phi_args [j + 1];
482 MonoMethodVar *mv = MONO_VARINFO (cfg, idx);
484 if (mv->reg != -1 && mv->reg != mv->idx) {
485 //printf ("PHICOPY %d %d -> %d\n", idx, mv->reg, inst->inst_i0->inst_c0);
490 if (idx != inst->inst_i0->inst_c0) {
492 printf ("MOVE %d to %d in BB%d\n", idx, inst->inst_i0->inst_c0, pred->block_num);
494 mono_add_varcopy_to_end (cfg, pred, idx, inst->inst_i0->inst_c0);
498 /* remove the phi functions */
499 inst->opcode = OP_NOP;
500 inst->ssa_op = MONO_SSA_NOP;
505 #ifndef USE_ORIGINAL_VARS
506 /* we compute liveness again */
507 cfg->comp_done &= ~MONO_COMP_LIVENESS;
508 mono_analyze_liveness (cfg);
510 varlist_array = mono_ssa_get_allocatable_vars (cfg);
512 for (i = 0; i < varlist_array->len; i++) {
513 GList *l, *regs, *vars = g_ptr_array_index (varlist_array, i);
514 MonoMethodVar *vmv, *amv;
516 if (g_list_length (vars) <= 1) {
523 for (l = vars; l; l = l->next) {
526 /* expire old intervals in active */
528 amv = (MonoMethodVar *)active->data;
530 if (amv->range.last_use.abs_pos >= vmv->range.first_use.abs_pos)
533 active = g_list_delete_link (active, active);
534 regs = g_list_prepend (regs, (gpointer)amv->reg);
538 regs = g_list_prepend (regs, (gpointer)vmv->idx);
540 vmv->reg = (int)regs->data;
541 regs = g_list_delete_link (regs, regs);
542 active = mono_varlist_insert_sorted (cfg, active, vmv, TRUE);
545 g_list_free (active);
550 g_ptr_array_free (varlist_array, TRUE);
554 is_live = alloca (cfg->num_varinfo);
555 memset (is_live, 0, cfg->num_varinfo);
557 for (i = 0; i < cfg->num_bblocks; ++i) {
558 MonoBasicBlock *bb = cfg->bblocks [i];
560 MONO_BB_FOR_EACH_INS (bb, inst)
561 mono_ssa_replace_copies (cfg, bb, inst, is_live);
564 for (i = 0; i < cfg->num_varinfo; ++i) {
565 MONO_VARINFO (cfg, i)->reg = -1;
566 if (!is_live [i] && !(cfg->varinfo [i]->flags & MONO_INST_VOLATILE)) {
567 cfg->varinfo [i]->flags |= MONO_INST_IS_DEAD;
571 if (cfg->comp_done & MONO_COMP_REACHABILITY)
572 unlink_unused_bblocks (cfg);
574 cfg->comp_done &= ~MONO_COMP_SSA;
578 #define IS_CALL(op) (op == CEE_CALLI || op == OP_CALL || op == OP_CALLVIRT || (op >= OP_VOIDCALL && op <= OP_CALL_MEMBASE))
589 * Returns TRUE if the tree can have side effects.
592 analyze_dev_use (MonoCompile *cfg, MonoBasicBlock *bb, MonoInst *root, MonoInst *inst)
596 gboolean has_side_effects;
601 arity = mono_burg_arity [inst->opcode];
602 switch (inst->opcode) {
603 #define ANALYZE_DEV_USE_SPECIFIC_OPS 1
604 #define OPDEF(a1,a2,a3,a4,a5,a6,a7,a8,a9,a10) case a1:
605 #include "simple-cee-ops.h"
607 #define MINI_OP(a1,a2) case a1:
608 #include "simple-mini-ops.h"
610 #undef ANALYZE_DEV_USE_SPECIFIC_OPS
611 has_side_effects = FALSE;
614 has_side_effects = TRUE;
617 if ((inst->ssa_op == MONO_SSA_STORE) &&
618 (inst->inst_i0->opcode == OP_LOCAL /*|| inst->inst_i0->opcode == OP_ARG */)) {
619 idx = inst->inst_i0->inst_c0;
620 info = MONO_VARINFO (cfg, idx);
621 //printf ("%d defined in BB%d %p\n", idx, bb->block_num, root);
623 g_warning ("more than one definition of variable %d in %s", idx,
624 mono_method_full_name (cfg->method, TRUE));
625 g_assert_not_reached ();
627 if (!IS_CALL (inst->inst_i1->opcode) /* && inst->inst_i1->opcode == OP_ICONST */) {
628 g_assert (inst == root);
633 if (inst->inst_i1->opcode == OP_PHI) {
634 for (i = inst->inst_i1->inst_phi_args [0]; i > 0; i--) {
635 MonoVarUsageInfo *ui = mono_mempool_alloc (cfg->mempool, sizeof (MonoVarUsageInfo));
636 idx = inst->inst_i1->inst_phi_args [i];
637 info = MONO_VARINFO (cfg, idx);
638 //printf ("FOUND %d\n", idx);
641 info->uses = g_list_prepend_mempool (info->uses, cfg->mempool, ui);
646 if ((inst->ssa_op == MONO_SSA_LOAD || inst->ssa_op == MONO_SSA_ADDRESS_TAKEN) &&
647 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG)) {
648 MonoVarUsageInfo *ui = mono_mempool_alloc (cfg->mempool, sizeof (MonoVarUsageInfo));
649 idx = inst->inst_i0->inst_c0;
650 info = MONO_VARINFO (cfg, idx);
651 //printf ("FOUND %d\n", idx);
654 info->uses = g_list_prepend_mempool (info->uses, cfg->mempool, ui);
657 //if (inst->ssa_op != MONO_SSA_STORE)
658 if (analyze_dev_use (cfg, bb, root, inst->inst_left))
659 has_side_effects = TRUE;
661 if (analyze_dev_use (cfg, bb, root, inst->inst_right))
662 has_side_effects = TRUE;
666 return has_side_effects;
670 /* avoid unnecessary copies of variables:
671 * Y <= X; Z = Y; is translated to Z = X;
674 mono_ssa_avoid_copies (MonoCompile *cfg)
676 MonoInst *inst, *next;
678 MonoMethodVar *i1, *i2;
680 g_assert ((cfg->comp_done & MONO_COMP_SSA_DEF_USE));
682 for (bb = cfg->bb_entry; bb; bb = bb->next_bb) {
683 MONO_BB_FOR_EACH_INS (bb, inst) {
684 if (inst->ssa_op == MONO_SSA_STORE && inst->inst_i0->opcode == OP_LOCAL &&
685 !IS_CALL (inst->inst_i1->opcode) && inst->inst_i1->opcode != OP_PHI && !inst->flags) {
686 i1 = MONO_VARINFO (cfg, inst->inst_i0->inst_c0);
688 /* fixme: compiling mcs does not work when I enable this */
690 if (g_list_length (i1->uses) == 1 && !extends_live (inst->inst_i1)) {
691 MonoVarUsageInfo *vi = (MonoVarUsageInfo *)i1->uses->data;
694 //printf ("VAR %d %s\n", i1->idx, mono_method_full_name (cfg->method, TRUE));
695 //mono_print_tree (inst); printf ("\n");
696 //mono_print_tree (u); printf ("\n");
698 if (replace_usage_new (cfg, u, inst->inst_i0->inst_c0, inst->inst_i1)) {
700 //mono_print_tree (u); printf ("\n");
702 inst->opcode = OP_NOP;
703 inst->ssa_op = MONO_SSA_NOP;
707 next = mono_inst_list_next (&inst->node, &bb->ins_list);
708 if (next && next->ssa_op == MONO_SSA_STORE &&
709 next->inst_i0->opcode == OP_LOCAL &&
710 next->inst_i1->ssa_op == MONO_SSA_LOAD &&
711 next->inst_i1->inst_i0->opcode == OP_LOCAL &&
712 next->inst_i1->inst_i0->inst_c0 == inst->inst_i0->inst_c0 &&
713 g_list_length (i1->uses) == 1 &&
714 inst->opcode == next->opcode &&
715 inst->inst_i0->type == next->inst_i0->type) {
716 i2 = MONO_VARINFO (cfg, next->inst_i0->inst_c0);
717 //printf ("ELIM. COPY in BB%d %s\n", bb->block_num, mono_method_full_name (cfg->method, TRUE));
718 inst->inst_i0 = next->inst_i0;
722 next->opcode = OP_NOP;
723 next->ssa_op = MONO_SSA_NOP;
731 mono_ssa_create_def_use (MonoCompile *cfg)
735 g_assert (!(cfg->comp_done & MONO_COMP_SSA_DEF_USE));
737 for (bb = cfg->bb_entry; bb; bb = bb->next_bb) {
739 MONO_BB_FOR_EACH_INS (bb, inst) {
740 gboolean has_side_effects = analyze_dev_use (cfg, bb, inst, inst);
741 if (has_side_effects && (inst->ssa_op == MONO_SSA_STORE) &&
742 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG)) {
743 inst->inst_i0->flags |= MONO_INST_DEFINITION_HAS_SIDE_EFFECTS;
748 cfg->comp_done |= MONO_COMP_SSA_DEF_USE;
752 simulate_compare (int opcode, int a, int b)
768 return (unsigned)a >= (unsigned)b;
770 return (unsigned)a > (unsigned)b;
772 return (unsigned)a <= (unsigned)b;
774 return (unsigned)a < (unsigned)b;
776 g_assert_not_reached ();
783 simulate_long_compare (int opcode, gint64 a, gint64 b)
799 return (guint64)a >= (guint64)b;
801 return (guint64)a > (guint64)b;
803 return (guint64)a <= (guint64)b;
805 return (guint64)a < (guint64)b;
807 g_assert_not_reached ();
813 #define EVAL_CXX(name,op,cast) \
815 if ((inst->inst_i0->opcode == OP_COMPARE) || (inst->inst_i0->opcode == OP_LCOMPARE)) { \
816 r1 = evaluate_const_tree (cfg, inst->inst_i0->inst_i0, &a, carray); \
817 r2 = evaluate_const_tree (cfg, inst->inst_i0->inst_i1, &b, carray); \
818 if (r1 == 1 && r2 == 1) { \
819 *res = ((cast)a op (cast)b); \
822 return MAX (r1, r2); \
827 #define EVAL_BINOP(name,op) \
829 r1 = evaluate_const_tree (cfg, inst->inst_i0, &a, carray); \
830 r2 = evaluate_const_tree (cfg, inst->inst_i1, &b, carray); \
831 if (r1 == 1 && r2 == 1) { \
835 return MAX (r1, r2); \
840 /* fixme: this only works for interger constants, but not for other types (long, float) */
842 evaluate_const_tree (MonoCompile *cfg, MonoInst *inst, int *res, MonoInst **carray)
850 if (inst->ssa_op == MONO_SSA_LOAD &&
851 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG) &&
852 (c0 = carray [inst->inst_i0->inst_c0])) {
857 switch (inst->opcode) {
859 *res = inst->inst_c0;
862 EVAL_CXX (OP_CEQ,==,gint32)
863 EVAL_CXX (OP_CGT,>,gint32)
864 EVAL_CXX (OP_CGT_UN,>,guint32)
865 EVAL_CXX (OP_CLT,<,gint32)
866 EVAL_CXX (OP_CLT_UN,<,guint32)
868 EVAL_BINOP (CEE_ADD,+)
869 EVAL_BINOP (CEE_SUB,-)
870 EVAL_BINOP (CEE_MUL,*)
871 EVAL_BINOP (CEE_AND,&)
872 EVAL_BINOP (CEE_OR,|)
873 EVAL_BINOP (CEE_XOR,^)
874 EVAL_BINOP (CEE_SHL,<<)
875 EVAL_BINOP (CEE_SHR,>>)
885 fold_tree (MonoCompile *cfg, MonoBasicBlock *bb, MonoInst *inst, MonoInst **carray)
893 arity = mono_burg_arity [inst->opcode];
895 if (inst->ssa_op == MONO_SSA_STORE &&
896 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG) &&
897 inst->inst_i1->opcode == OP_PHI && (c0 = carray [inst->inst_i0->inst_c0])) {
898 //{static int cn = 0; printf ("PHICONST %d %d %s\n", cn++, c0->inst_c0, mono_method_full_name (cfg->method, TRUE));}
899 *inst->inst_i1 = *c0;
900 } else if (inst->ssa_op == MONO_SSA_LOAD &&
901 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG) &&
902 (c0 = carray [inst->inst_i0->inst_c0])) {
903 //{static int cn = 0; printf ("YCCOPY %d %d %s\n", cn++, c0->inst_c0, mono_method_full_name (cfg->method, TRUE));}
908 fold_tree (cfg, bb, inst->inst_left, carray);
910 fold_tree (cfg, bb, inst->inst_right, carray);
911 mono_constant_fold_inst (inst, NULL);
915 if ((inst->opcode >= CEE_BEQ && inst->opcode <= CEE_BLT_UN) &&
916 ((inst->inst_i0->opcode == OP_COMPARE) || (inst->inst_i0->opcode == OP_LCOMPARE))) {
917 MonoInst *v0 = inst->inst_i0->inst_i0;
918 MonoInst *v1 = inst->inst_i0->inst_i1;
919 MonoBasicBlock *target = NULL;
921 /* hack for longs to optimize the simply cases */
922 if (v0->opcode == OP_I8CONST && v1->opcode == OP_I8CONST) {
923 if (simulate_long_compare (inst->opcode, v0->inst_l, v1->inst_l)) {
924 //unlink_target (bb, inst->inst_false_bb);
925 target = inst->inst_true_bb;
927 //unlink_target (bb, inst->inst_true_bb);
928 target = inst->inst_false_bb;
930 } else if (evaluate_const_tree (cfg, v0, &a, carray) == 1 &&
931 evaluate_const_tree (cfg, v1, &b, carray) == 1) {
932 if (simulate_compare (inst->opcode, a, b)) {
933 //unlink_target (bb, inst->inst_false_bb);
934 target = inst->inst_true_bb;
936 //unlink_target (bb, inst->inst_true_bb);
937 target = inst->inst_false_bb;
942 bb->out_bb [0] = target;
944 inst->opcode = OP_BR;
945 inst->inst_target_bb = target;
947 } else if (inst->opcode == OP_SWITCH && (evaluate_const_tree (cfg, inst->inst_left, &a, carray) == 1) && (a >= 0) && (a < GPOINTER_TO_INT (inst->klass))) {
948 bb->out_bb [0] = inst->inst_many_bb [a];
950 inst->inst_target_bb = bb->out_bb [0];
951 inst->opcode = OP_BR;
957 change_varstate (MonoCompile *cfg, GList **cvars, MonoMethodVar *info, int state, MonoInst *c0, MonoInst **carray)
959 if (info->cpstate >= state)
962 info->cpstate = state;
964 //printf ("SETSTATE %d to %d\n", info->idx, info->cpstate);
967 carray [info->idx] = c0;
969 carray [info->idx] = NULL;
971 if (!g_list_find (*cvars, info)) {
972 *cvars = g_list_prepend (*cvars, info);
977 visit_inst (MonoCompile *cfg, MonoBasicBlock *bb, MonoInst *inst, GList **cvars, GList **bblist, MonoInst **carray)
981 if (inst->opcode == OP_SWITCH) {
983 int cases = GPOINTER_TO_INT (inst->klass);
985 r1 = evaluate_const_tree (cfg, inst->inst_left, &a, carray);
986 if ((r1 == 1) && ((a < 0) || (a >= cases)))
989 MonoBasicBlock *tb = inst->inst_many_bb [a];
990 if (!(tb->flags & BB_REACHABLE)) {
991 tb->flags |= BB_REACHABLE;
992 *bblist = g_list_prepend (*bblist, tb);
994 } else if (r1 == 2) {
995 for (i = GPOINTER_TO_INT (inst->klass); i >= 0; i--) {
996 MonoBasicBlock *tb = inst->inst_many_bb [i];
997 if (!(tb->flags & BB_REACHABLE)) {
998 tb->flags |= BB_REACHABLE;
999 *bblist = g_list_prepend (*bblist, tb);
1003 } else if (inst->opcode == OP_BR) {
1004 MonoBasicBlock *target = inst->inst_target_bb;
1006 if (!(target->flags & BB_REACHABLE)) {
1007 target->flags |= BB_REACHABLE;
1008 *bblist = g_list_prepend (*bblist, target);
1010 } else if ((inst->opcode >= CEE_BEQ && inst->opcode <= CEE_BLT_UN) &&
1011 ((inst->inst_i0->opcode == OP_COMPARE) || (inst->inst_i0->opcode == OP_LCOMPARE))) {
1013 MonoInst *v0 = inst->inst_i0->inst_i0;
1014 MonoInst *v1 = inst->inst_i0->inst_i1;
1016 r1 = evaluate_const_tree (cfg, v0, &a, carray);
1017 r2 = evaluate_const_tree (cfg, v1, &b, carray);
1019 if (r1 == 1 && r2 == 1) {
1020 MonoBasicBlock *target;
1022 if (simulate_compare (inst->opcode, a, b)) {
1023 target = inst->inst_true_bb;
1025 target = inst->inst_false_bb;
1027 if (!(target->flags & BB_REACHABLE)) {
1028 target->flags |= BB_REACHABLE;
1029 *bblist = g_list_prepend (*bblist, target);
1031 } else if (r1 == 2 || r2 == 2) {
1032 if (!(inst->inst_true_bb->flags & BB_REACHABLE)) {
1033 inst->inst_true_bb->flags |= BB_REACHABLE;
1034 *bblist = g_list_prepend (*bblist, inst->inst_true_bb);
1036 if (!(inst->inst_false_bb->flags & BB_REACHABLE)) {
1037 inst->inst_false_bb->flags |= BB_REACHABLE;
1038 *bblist = g_list_prepend (*bblist, inst->inst_false_bb);
1041 } else if (inst->ssa_op == MONO_SSA_STORE &&
1042 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG)) {
1043 MonoMethodVar *info = MONO_VARINFO (cfg, inst->inst_i0->inst_c0);
1044 MonoInst *i1 = inst->inst_i1;
1047 if (info->cpstate < 2) {
1048 if (i1->opcode == OP_ICONST) {
1049 change_varstate (cfg, cvars, info, 1, i1, carray);
1050 } else if (i1->opcode == OP_PHI) {
1051 MonoInst *c0 = NULL;
1054 for (j = 1; j <= i1->inst_phi_args [0]; j++) {
1055 MonoMethodVar *mv = MONO_VARINFO (cfg, i1->inst_phi_args [j]);
1056 MonoInst *src = mv->def;
1058 if (mv->def_bb && !(mv->def_bb->flags & BB_REACHABLE)) {
1062 if (!mv->def || !src || src->ssa_op != MONO_SSA_STORE ||
1063 !(src->inst_i0->opcode == OP_LOCAL || src->inst_i0->opcode == OP_ARG) ||
1065 change_varstate (cfg, cvars, info, 2, NULL, carray);
1069 if (mv->cpstate == 0)
1072 //g_assert (src->inst_i1->opcode == OP_ICONST);
1073 g_assert (carray [mv->idx]);
1076 c0 = carray [mv->idx];
1079 if (carray [mv->idx]->inst_c0 != c0->inst_c0) {
1080 change_varstate (cfg, cvars, info, 2, NULL, carray);
1085 if (c0 && info->cpstate < 1) {
1086 change_varstate (cfg, cvars, info, 1, c0, carray);
1089 int state = evaluate_const_tree (cfg, i1, &res, carray);
1091 NEW_ICONST (cfg, i1, res);
1092 change_varstate (cfg, cvars, info, 1, i1, carray);
1094 change_varstate (cfg, cvars, info, 2, NULL, carray);
1102 mono_ssa_cprop (MonoCompile *cfg)
1106 GList *bblock_list, *cvars;
1109 //printf ("SIMPLE OPTS BB%d %s\n", bb->block_num, mono_method_full_name (cfg->method, TRUE));
1111 carray = g_new0 (MonoInst*, cfg->num_varinfo);
1113 if (!(cfg->comp_done & MONO_COMP_SSA_DEF_USE))
1114 mono_ssa_create_def_use (cfg);
1116 bblock_list = g_list_prepend (NULL, cfg->bb_entry);
1117 cfg->bb_entry->flags |= BB_REACHABLE;
1119 memset (carray, 0, sizeof (MonoInst *) * cfg->num_varinfo);
1121 for (i = 0; i < cfg->num_varinfo; i++) {
1122 MonoMethodVar *info = MONO_VARINFO (cfg, i);
1129 while (bblock_list) {
1132 bb = (MonoBasicBlock *)bblock_list->data;
1134 bblock_list = g_list_delete_link (bblock_list, bblock_list);
1136 g_assert (bb->flags & BB_REACHABLE);
1138 if (bb->out_count == 1) {
1139 if (!(bb->out_bb [0]->flags & BB_REACHABLE)) {
1140 bb->out_bb [0]->flags |= BB_REACHABLE;
1141 bblock_list = g_list_prepend (bblock_list, bb->out_bb [0]);
1145 MONO_BB_FOR_EACH_INS (bb, inst)
1146 visit_inst (cfg, bb, inst, &cvars, &bblock_list, carray);
1149 MonoMethodVar *info = (MonoMethodVar *)cvars->data;
1150 cvars = g_list_delete_link (cvars, cvars);
1152 for (tmp = info->uses; tmp; tmp = tmp->next) {
1153 MonoVarUsageInfo *ui = (MonoVarUsageInfo *)tmp->data;
1154 if (!(ui->bb->flags & BB_REACHABLE))
1156 visit_inst (cfg, ui->bb, ui->inst, &cvars, &bblock_list, carray);
1161 for (bb = cfg->bb_entry->next_bb; bb; bb = bb->next_bb) {
1163 MONO_BB_FOR_EACH_INS (bb, inst)
1164 fold_tree (cfg, bb, inst, carray);
1169 cfg->comp_done |= MONO_COMP_REACHABILITY;
1173 add_to_dce_worklist (MonoCompile *cfg, MonoMethodVar *var, MonoMethodVar *use, GList **wl)
1177 *wl = g_list_prepend (*wl, use);
1179 for (tmp = use->uses; tmp; tmp = tmp->next) {
1180 MonoVarUsageInfo *ui = (MonoVarUsageInfo *)tmp->data;
1181 if (ui->inst == var->def) {
1182 /* from the mempool */
1183 use->uses = g_list_remove_link (use->uses, tmp);
1190 mono_ssa_deadce (MonoCompile *cfg)
1195 g_assert (cfg->comp_done & MONO_COMP_SSA);
1197 //printf ("DEADCE %s\n", mono_method_full_name (cfg->method, TRUE));
1199 /* fixme: we should update usage infos during cprop, instead of computing it again */
1200 cfg->comp_done &= ~MONO_COMP_SSA_DEF_USE;
1201 for (i = 0; i < cfg->num_varinfo; i++) {
1202 MonoMethodVar *info = MONO_VARINFO (cfg, i);
1207 if (!(cfg->comp_done & MONO_COMP_SSA_DEF_USE))
1208 mono_ssa_create_def_use (cfg);
1210 mono_ssa_avoid_copies (cfg);
1213 for (i = 0; i < cfg->num_varinfo; i++) {
1214 MonoMethodVar *info = MONO_VARINFO (cfg, i);
1215 work_list = g_list_prepend (work_list, info);
1217 //if ((info->def != NULL) && (info->def->inst_i1->opcode != OP_PHI)) printf ("SSA DEADCE TOTAL LOCAL\n");
1221 MonoMethodVar *info = (MonoMethodVar *)work_list->data;
1222 work_list = g_list_delete_link (work_list, work_list);
1224 if (!info->uses && info->def && (!(cfg->varinfo [info->idx]->flags & (MONO_INST_DEFINITION_HAS_SIDE_EFFECTS|MONO_INST_VOLATILE|MONO_INST_INDIRECT)))) {
1226 //printf ("ELIMINATE %s: ", mono_method_full_name (cfg->method, TRUE)); mono_print_tree (info->def); printf ("\n");
1228 i1 = info->def->inst_i1;
1229 if (i1->opcode == OP_PHI) {
1231 for (j = i1->inst_phi_args [0]; j > 0; j--) {
1232 MonoMethodVar *u = MONO_VARINFO (cfg, i1->inst_phi_args [j]);
1233 add_to_dce_worklist (cfg, info, u, &work_list);
1235 } else if (i1->ssa_op == MONO_SSA_LOAD &&
1236 (i1->inst_i0->opcode == OP_LOCAL || i1->inst_i0->opcode == OP_ARG)) {
1237 MonoMethodVar *u = MONO_VARINFO (cfg, i1->inst_i0->inst_c0);
1238 add_to_dce_worklist (cfg, info, u, &work_list);
1240 //if (i1->opcode != OP_PHI) printf ("SSA DEADCE DEAD LOCAL\n");
1242 info->def->opcode = OP_NOP;
1243 info->def->ssa_op = MONO_SSA_NOP;
1251 mono_ssa_strength_reduction (MonoCompile *cfg)
1256 g_assert (cfg->comp_done & MONO_COMP_SSA);
1257 g_assert (cfg->comp_done & MONO_COMP_LOOPS);
1258 g_assert (cfg->comp_done & MONO_COMP_SSA_DEF_USE);
1260 for (bb = cfg->bb_entry->next_bb; bb; bb = bb->next_bb) {
1261 GList *lp = bb->loop_blocks;
1264 MonoBasicBlock *h = (MonoBasicBlock *)lp->data;
1266 /* we only consider loops with 2 in bblocks */
1267 if (!h->in_count == 2)
1270 for (i = 0; i < cfg->num_varinfo; i++) {
1271 MonoMethodVar *info = MONO_VARINFO (cfg, i);
1273 if (info->def && info->def->ssa_op == MONO_SSA_STORE &&
1274 info->def->inst_i0->opcode == OP_LOCAL && g_list_find (lp, info->def_bb)) {
1275 MonoInst *v = info->def->inst_i1;
1278 printf ("FOUND %d in %s\n", info->idx, mono_method_full_name (cfg->method, TRUE));
1286 #endif /* DISABLE_SSA */