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>
14 extern guint8 mono_burg_arity [];
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 unlink_target (MonoBasicBlock *bb, MonoBasicBlock *target)
40 for (i = 0; i < bb->out_count; i++) {
41 if (bb->out_bb [i] == target) {
42 bb->out_bb [i] = bb->out_bb [--bb->out_count];
46 for (i = 0; i < target->in_count; i++) {
47 if (target->in_bb [i] == bb) {
48 target->in_bb [i] = target->in_bb [--target->in_count];
56 unlink_unused_bblocks (MonoCompile *cfg)
61 g_assert (cfg->comp_done & MONO_COMP_REACHABILITY);
63 for (bb = cfg->bb_entry; bb && bb->next_bb;) {
64 if (!(bb->next_bb->flags & BB_REACHABLE)) {
65 bb->next_bb = bb->next_bb->next_bb;
70 for (i = 1; i < cfg->num_bblocks; i++) {
71 bb = cfg->bblocks [i];
73 if (!(bb->flags & BB_REACHABLE)) {
74 for (j = 0; j < bb->in_count; j++) {
75 unlink_target (bb->in_bb [j], bb);
77 for (j = 0; j < bb->out_count; j++) {
78 unlink_target (bb, bb->out_bb [j]);
88 replace_usage (MonoCompile *cfg, MonoBasicBlock *bb, MonoInst *inst, MonoInst **stack)
95 arity = mono_burg_arity [inst->opcode];
97 if ((inst->ssa_op == MONO_SSA_LOAD || inst->ssa_op == MONO_SSA_MAYBE_LOAD) &&
98 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG)) {
100 int idx = inst->inst_i0->inst_c0;
103 new_var = stack [idx];
105 new_var = cfg->varinfo [idx];
107 if ((new_var->opcode != OP_ARG) && (new_var->opcode != OP_LOCAL)) {
108 /* uninitialized variable ? */
109 g_warning ("using uninitialized variables %d in BB%d (%s)", idx, bb->block_num,
110 mono_method_full_name (cfg->method, TRUE));
111 //g_assert_not_reached ();
115 printf ("REPLACE BB%d %d %d\n", bb->block_num, idx, new_var->inst_c0);
117 inst->inst_i0 = new_var;
121 if (inst->ssa_op != MONO_SSA_STORE)
122 replace_usage (cfg, bb, inst->inst_left, stack);
124 replace_usage (cfg, bb, inst->inst_right, stack);
130 extends_live (MonoInst *inst)
137 arity = mono_burg_arity [inst->opcode];
139 if (inst->ssa_op == MONO_SSA_LOAD &&
140 (inst->inst_i0->opcode == OP_LOCAL /*|| inst->inst_i0->opcode == OP_ARG*/)) {
144 if (inst->ssa_op != MONO_SSA_STORE)
145 if (extends_live (inst->inst_left))
148 if (extends_live (inst->inst_right))
157 replace_usage_new (MonoCompile *cfg, MonoInst *inst, int varnum, MonoInst *rep)
164 arity = mono_burg_arity [inst->opcode];
166 if ((inst->ssa_op == MONO_SSA_LOAD) &&
167 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG) &&
168 inst->inst_i0->inst_c0 == varnum && rep->type == inst->type) {
173 if (inst->ssa_op != MONO_SSA_STORE)
174 if (replace_usage_new (cfg, inst->inst_left, varnum, rep))
177 if (replace_usage_new (cfg, inst->inst_right, varnum, rep))
186 mono_ssa_rename_vars (MonoCompile *cfg, int max_vars, MonoBasicBlock *bb, MonoInst **stack)
188 MonoInst *inst, *new_var;
191 MonoInst **new_stack;
194 printf ("RENAME VARS BB%d %s\n", bb->block_num, mono_method_full_name (cfg->method, TRUE));
197 for (inst = bb->code; inst; inst = inst->next) {
198 if (inst->opcode != OP_PHI)
199 replace_usage (cfg, bb, inst, stack);
201 if (inst->ssa_op == MONO_SSA_STORE &&
202 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG)) {
203 idx = inst->inst_i0->inst_c0;
204 g_assert (idx < max_vars);
206 if (!stack [idx] && bb == cfg->bb_init) {
207 new_var = cfg->varinfo [idx];
209 new_var = mono_compile_create_var (cfg, inst->inst_i0->inst_vtype, inst->inst_i0->opcode);
210 new_var->flags = inst->inst_i0->flags;
213 printf ("DEF %d %d\n", idx, new_var->inst_c0);
215 inst->inst_i0 = new_var;
217 #ifdef USE_ORIGINAL_VARS
218 cfg->vars [new_var->inst_c0]->reg = idx;
221 stack [idx] = new_var;
225 for (i = 0; i < bb->out_count; i++) {
226 MonoBasicBlock *n = bb->out_bb [i];
228 for (j = 0; j < n->in_count; j++)
229 if (n->in_bb [j] == bb)
232 for (inst = n->code; inst; inst = inst->next) {
233 if (inst->ssa_op == MONO_SSA_STORE && inst->inst_i1->opcode == OP_PHI) {
234 idx = inst->inst_i1->inst_c0;
236 new_var = stack [idx];
238 new_var = cfg->varinfo [idx];
240 printf ("FOUND PHI %d (%d, %d)\n", idx, j, new_var->inst_c0);
242 inst->inst_i1->inst_phi_args [j + 1] = new_var->inst_c0;
249 new_stack = g_new (MonoInst*, max_vars);
250 for (tmp = bb->dominated; tmp; tmp = tmp->next) {
251 memcpy (new_stack, stack, sizeof (MonoInst *) * max_vars);
252 mono_ssa_rename_vars (cfg, max_vars, (MonoBasicBlock *)tmp->data, new_stack);
259 mono_ssa_compute (MonoCompile *cfg)
263 MonoMethodVar *vinfo = g_new0 (MonoMethodVar, cfg->num_varinfo);
264 MonoInst *inst, *store, **stack;
266 g_assert (!(cfg->comp_done & MONO_COMP_SSA));
268 /* we dont support methods containing exception clauses */
269 g_assert (((MonoMethodNormal *)cfg->method)->header->num_clauses == 0);
270 g_assert (!cfg->disable_ssa);
272 //printf ("COMPUTS SSA %s %d\n", mono_method_full_name (cfg->method, TRUE), cfg->num_varinfo);
274 #ifdef CREATE_PRUNED_SSA
275 /* we need liveness for pruned SSA */
276 if (!(cfg->comp_done & MONO_COMP_LIVENESS))
277 mono_analyze_liveness (cfg);
280 mono_compile_dominator_info (cfg, MONO_COMP_DOM | MONO_COMP_IDOM | MONO_COMP_DFRONTIER);
282 for (i = 0; i < cfg->num_varinfo; ++i) {
283 vinfo [i].def_in = mono_bitset_new (cfg->num_bblocks, 0);
285 /* implizit reference at start */
286 mono_bitset_set (vinfo [i].def_in, 0);
288 for (i = 0; i < cfg->num_bblocks; ++i) {
289 for (inst = cfg->bblocks [i]->code; inst; inst = inst->next) {
290 if (inst->ssa_op == MONO_SSA_STORE) {
291 idx = inst->inst_i0->inst_c0;
292 g_assert (idx < cfg->num_varinfo);
293 mono_bitset_set (vinfo [idx].def_in, i);
298 /* insert phi functions */
299 for (i = 0; i < cfg->num_varinfo; ++i) {
300 set = mono_compile_iterated_dfrontier (cfg, vinfo [i].def_in);
301 vinfo [i].dfrontier = set;
302 mono_bitset_foreach_bit (set, idx, cfg->num_bblocks) {
303 MonoBasicBlock *bb = cfg->bblocks [idx];
305 /* fixme: create pruned SSA? we would need liveness information for that */
307 if (bb == cfg->bb_exit)
310 if ((cfg->comp_done & MONO_COMP_LIVENESS) && !mono_bitset_test_fast (bb->live_in_set, i)) {
311 //printf ("%d is not live in BB%d %s\n", i, bb->block_num, mono_method_full_name (cfg->method, TRUE));
315 NEW_PHI (cfg, inst, i);
317 inst->inst_phi_args = mono_mempool_alloc0 (cfg->mempool, sizeof (int) * (cfg->bblocks [idx]->in_count + 1));
318 inst->inst_phi_args [0] = cfg->bblocks [idx]->in_count;
320 store = mono_mempool_alloc0 ((cfg)->mempool, sizeof (MonoInst));
321 if (!cfg->varinfo [i]->inst_vtype->type)
322 g_assert_not_reached ();
323 store->opcode = mono_type_to_stind (cfg->varinfo [i]->inst_vtype);
324 store->ssa_op = MONO_SSA_STORE;
325 store->inst_i0 = cfg->varinfo [i];
326 store->inst_i1 = inst;
327 store->klass = store->inst_i0->klass;
329 store->next = bb->code;
333 printf ("ADD PHI BB%d %s\n", cfg->bblocks [idx]->block_num, mono_method_full_name (cfg->method, TRUE));
339 for (i = 0; i < cfg->num_varinfo; ++i)
340 mono_bitset_free (vinfo [i].def_in);
344 stack = alloca (sizeof (MonoInst *) * cfg->num_varinfo);
346 for (i = 0; i < cfg->num_varinfo; i++)
349 mono_ssa_rename_vars (cfg, cfg->num_varinfo, cfg->bb_entry, stack);
351 cfg->comp_done |= MONO_COMP_SSA;
354 #ifndef USE_ORIGINAL_VARS
356 mono_ssa_get_allocatable_vars (MonoCompile *cfg)
358 GHashTable *type_hash;
359 GPtrArray *varlist_array = g_ptr_array_new ();
362 g_assert (cfg->comp_done & MONO_COMP_LIVENESS);
364 type_hash = g_hash_table_new (NULL, NULL);
366 for (i = 0; i < cfg->num_varinfo; i++) {
367 MonoInst *ins = cfg->varinfo [i];
368 MonoMethodVar *vmv = MONO_VARINFO (cfg, i);
371 if (vmv->range.first_use.abs_pos > vmv->range.last_use.abs_pos)
374 if (ins->flags & (MONO_INST_VOLATILE|MONO_INST_INDIRECT) ||
375 (ins->opcode != OP_LOCAL && ins->opcode != OP_ARG) || vmv->reg != -1)
378 g_assert (ins->inst_vtype);
379 g_assert (vmv->reg == -1);
380 g_assert (i == vmv->idx);
382 if (!(tidx = (int)g_hash_table_lookup (type_hash, ins->inst_vtype))) {
383 GList *vars = g_list_append (NULL, vmv);
384 g_ptr_array_add (varlist_array, vars);
385 g_hash_table_insert (type_hash, ins->inst_vtype, (gpointer)varlist_array->len);
388 g_ptr_array_index (varlist_array, tidx) =
389 mono_varlist_insert_sorted (cfg, g_ptr_array_index (varlist_array, tidx), vmv, FALSE);
393 g_hash_table_destroy (type_hash);
395 return varlist_array;
400 mono_ssa_replace_copies (MonoCompile *cfg, MonoBasicBlock *bb, MonoInst *inst, char *is_live)
407 arity = mono_burg_arity [inst->opcode];
409 if ((inst->ssa_op == MONO_SSA_LOAD || inst->ssa_op == MONO_SSA_MAYBE_LOAD || inst->ssa_op == MONO_SSA_STORE) &&
410 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG)) {
412 int idx = inst->inst_i0->inst_c0;
413 MonoMethodVar *mv = cfg->vars [idx];
415 if (mv->reg != -1 && mv->reg != mv->idx) {
417 is_live [mv->reg] = 1;
419 new_var = cfg->varinfo [mv->reg];
422 printf ("REPLACE COPY BB%d %d %d\n", bb->block_num, idx, new_var->inst_c0);
423 g_assert (cfg->varinfo [mv->reg]->inst_vtype == cfg->varinfo [idx]->inst_vtype);
425 inst->inst_i0 = new_var;
427 is_live [mv->idx] = 1;
433 mono_ssa_replace_copies (cfg, bb, inst->inst_left, is_live);
435 mono_ssa_replace_copies (cfg, bb, inst->inst_right, is_live);
438 if (inst->ssa_op == MONO_SSA_STORE && inst->inst_i1->ssa_op == MONO_SSA_LOAD &&
439 inst->inst_i0->inst_c0 == inst->inst_i1->inst_i0->inst_c0) {
440 inst->ssa_op = MONO_SSA_NOP;
441 inst->opcode = CEE_NOP;
447 mono_ssa_remove (MonoCompile *cfg)
449 MonoInst *inst, *phi;
452 #ifndef USE_ORIGINAL_VARS
453 GPtrArray *varlist_array;
456 g_assert (cfg->comp_done & MONO_COMP_SSA);
458 for (i = 0; i < cfg->num_bblocks; ++i) {
459 MonoBasicBlock *bb = cfg->bblocks [i];
460 for (inst = bb->code; inst; inst = inst->next) {
461 if (inst->ssa_op == MONO_SSA_STORE && inst->inst_i1->opcode == OP_PHI) {
464 g_assert (phi->inst_phi_args [0] == bb->in_count);
466 for (j = 0; j < bb->in_count; j++) {
467 MonoBasicBlock *pred = bb->in_bb [j];
468 int idx = phi->inst_phi_args [j + 1];
469 MonoMethodVar *mv = cfg->vars [idx];
471 if (mv->reg != -1 && mv->reg != mv->idx) {
472 //printf ("PHICOPY %d %d -> %d\n", idx, mv->reg, inst->inst_i0->inst_c0);
477 if (idx != inst->inst_i0->inst_c0) {
479 printf ("MOVE %d to %d in BB%d\n", idx, inst->inst_i0->inst_c0, pred->block_num);
481 mono_add_varcopy_to_end (cfg, pred, idx, inst->inst_i0->inst_c0);
485 /* remove the phi functions */
486 inst->opcode = CEE_NOP;
487 inst->ssa_op = MONO_SSA_NOP;
492 #ifndef USE_ORIGINAL_VARS
493 /* we compute liveness again */
494 cfg->comp_done &= ~MONO_COMP_LIVENESS;
495 mono_analyze_liveness (cfg);
497 varlist_array = mono_ssa_get_allocatable_vars (cfg);
499 for (i = 0; i < varlist_array->len; i++) {
500 GList *l, *regs, *vars = g_ptr_array_index (varlist_array, i);
501 MonoMethodVar *vmv, *amv;
503 if (g_list_length (vars) <= 1) {
510 for (l = vars; l; l = l->next) {
513 /* expire old intervals in active */
515 amv = (MonoMethodVar *)active->data;
517 if (amv->range.last_use.abs_pos >= vmv->range.first_use.abs_pos)
520 active = g_list_remove_link (active, active);
521 regs = g_list_prepend (regs, (gpointer)amv->reg);
525 regs = g_list_prepend (regs, (gpointer)vmv->idx);
527 vmv->reg = (int)regs->data;
528 regs = g_list_remove_link (regs, regs);
529 active = mono_varlist_insert_sorted (cfg, active, vmv, TRUE);
532 g_list_free (active);
537 g_ptr_array_free (varlist_array, TRUE);
541 is_live = alloca (cfg->num_varinfo);
542 memset (is_live, 0, cfg->num_varinfo);
544 for (i = 0; i < cfg->num_bblocks; ++i) {
545 MonoBasicBlock *bb = cfg->bblocks [i];
547 for (inst = bb->code; inst; inst = inst->next)
548 mono_ssa_replace_copies (cfg, bb, inst, is_live);
551 for (i = 0; i < cfg->num_varinfo; ++i) {
552 cfg->vars [i]->reg = -1;
554 cfg->varinfo [i]->flags |= MONO_INST_IS_DEAD;
558 if (cfg->comp_done & MONO_COMP_REACHABILITY)
559 unlink_unused_bblocks (cfg);
561 cfg->comp_done &= ~MONO_COMP_SSA;
565 #define IS_CALL(op) (op == CEE_CALLI || op == CEE_CALL || op == CEE_CALLVIRT || (op >= OP_VOIDCALL && op <= OP_CALL_MEMBASE))
573 analyze_dev_use (MonoCompile *cfg, MonoBasicBlock *bb, MonoInst *root, MonoInst *inst)
581 arity = mono_burg_arity [inst->opcode];
583 if ((inst->ssa_op == MONO_SSA_STORE) &&
584 (inst->inst_i0->opcode == OP_LOCAL /*|| inst->inst_i0->opcode == OP_ARG */)) {
585 idx = inst->inst_i0->inst_c0;
586 info = cfg->vars [idx];
587 //printf ("%d defined in BB%d %p\n", idx, bb->block_num, root);
589 g_warning ("more than one definition of variable %d in %s", idx,
590 mono_method_full_name (cfg->method, TRUE));
591 g_assert_not_reached ();
593 if (!IS_CALL (inst->inst_i1->opcode) /* && inst->inst_i1->opcode == OP_ICONST */) {
594 g_assert (inst == root);
599 if (inst->inst_i1->opcode == OP_PHI) {
600 for (i = inst->inst_i1->inst_phi_args [0]; i > 0; i--) {
601 MonoVarUsageInfo *ui = mono_mempool_alloc (cfg->mempool, sizeof (MonoVarUsageInfo));
602 idx = inst->inst_i1->inst_phi_args [i];
603 info = cfg->vars [idx];
604 //printf ("FOUND %d\n", idx);
607 info->uses = g_list_prepend (info->uses, ui);
612 if ((inst->ssa_op == MONO_SSA_LOAD || inst->ssa_op == MONO_SSA_MAYBE_LOAD) &&
613 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG)) {
614 MonoVarUsageInfo *ui = mono_mempool_alloc (cfg->mempool, sizeof (MonoVarUsageInfo));
615 idx = inst->inst_i0->inst_c0;
616 info = cfg->vars [idx];
617 //printf ("FOUND %d\n", idx);
620 info->uses = g_list_prepend (info->uses, ui);
623 //if (inst->ssa_op != MONO_SSA_STORE)
624 analyze_dev_use (cfg, bb, root, inst->inst_left);
626 analyze_dev_use (cfg, bb, root, inst->inst_right);
632 /* avoid unnecessary copies of variables:
633 * Y <= X; Z = Y; is translated to Z = X;
636 mono_ssa_avoid_copies (MonoCompile *cfg)
638 MonoInst *inst, *next;
640 MonoMethodVar *i1, *i2;
642 g_assert ((cfg->comp_done & MONO_COMP_SSA_DEF_USE));
644 for (bb = cfg->bb_entry; bb; bb = bb->next_bb) {
645 for (inst = bb->code; inst; inst = inst->next) {
646 if (inst->ssa_op == MONO_SSA_STORE && inst->inst_i0->opcode == OP_LOCAL &&
647 !IS_CALL (inst->inst_i1->opcode) && inst->inst_i1->opcode != OP_PHI && !inst->flags) {
648 i1 = cfg->vars [inst->inst_i0->inst_c0];
650 /* fixme: compiling mcs does not work when I enable this */
652 if (g_list_length (i1->uses) == 1 && !extends_live (inst->inst_i1)) {
653 MonoVarUsageInfo *vi = (MonoVarUsageInfo *)i1->uses->data;
656 //printf ("VAR %d %s\n", i1->idx, mono_method_full_name (cfg->method, TRUE));
657 //mono_print_tree (inst); printf ("\n");
658 //mono_print_tree (u); printf ("\n");
660 if (replace_usage_new (cfg, u, inst->inst_i0->inst_c0, inst->inst_i1)) {
662 //mono_print_tree (u); printf ("\n");
664 inst->opcode = CEE_NOP;
665 inst->ssa_op = MONO_SSA_NOP;
669 if ((next = inst->next) && next->ssa_op == MONO_SSA_STORE && next->inst_i0->opcode == OP_LOCAL &&
670 next->inst_i1->ssa_op == MONO_SSA_LOAD && next->inst_i1->inst_i0->opcode == OP_LOCAL &&
671 next->inst_i1->inst_i0->inst_c0 == inst->inst_i0->inst_c0 && g_list_length (i1->uses) == 1 &&
672 inst->opcode == next->opcode && inst->inst_i0->type == next->inst_i0->type) {
673 i2 = cfg->vars [next->inst_i0->inst_c0];
674 //printf ("ELIM. COPY in BB%d %s\n", bb->block_num, mono_method_full_name (cfg->method, TRUE));
675 inst->inst_i0 = next->inst_i0;
678 g_list_free (i1->uses);
680 next->opcode = CEE_NOP;
681 next->ssa_op = MONO_SSA_NOP;
689 mono_ssa_create_def_use (MonoCompile *cfg)
693 g_assert (!(cfg->comp_done & MONO_COMP_SSA_DEF_USE));
695 for (bb = cfg->bb_entry; bb; bb = bb->next_bb) {
697 for (inst = bb->code; inst; inst = inst->next) {
698 analyze_dev_use (cfg, bb, inst, inst);
702 cfg->comp_done |= MONO_COMP_SSA_DEF_USE;
706 simulate_compare (int opcode, int a, int b)
722 return (unsigned)a >= (unsigned)b;
724 return (unsigned)a > (unsigned)b;
726 return (unsigned)a <= (unsigned)b;
728 return (unsigned)a < (unsigned)b;
730 g_assert_not_reached ();
737 simulate_long_compare (int opcode, gint64 a, gint64 b)
753 return (unsigned)a >= (unsigned)b;
755 return (unsigned)a > (unsigned)b;
757 return (unsigned)a <= (unsigned)b;
759 return (unsigned)a < (unsigned)b;
761 g_assert_not_reached ();
767 #define EVAL_CXX(name,op,cast) \
769 if (inst->inst_i0->opcode == OP_COMPARE) { \
770 r1 = evaluate_const_tree (cfg, inst->inst_i0->inst_i0, &a, carray); \
771 r2 = evaluate_const_tree (cfg, inst->inst_i0->inst_i1, &b, carray); \
772 if (r1 == 1 && r2 == 1) { \
773 *res = ((cast)a op (cast)b); \
776 return MAX (r1, r2); \
781 #define EVAL_BINOP(name,op) \
783 r1 = evaluate_const_tree (cfg, inst->inst_i0, &a, carray); \
784 r2 = evaluate_const_tree (cfg, inst->inst_i1, &b, carray); \
785 if (r1 == 1 && r2 == 1) { \
789 return MAX (r1, r2); \
794 /* fixme: this only works for interger constants, but not for other types (long, float) */
796 evaluate_const_tree (MonoCompile *cfg, MonoInst *inst, int *res, MonoInst **carray)
804 if (inst->ssa_op == MONO_SSA_LOAD &&
805 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG) &&
806 (c0 = carray [inst->inst_i0->inst_c0])) {
811 switch (inst->opcode) {
813 *res = inst->inst_c0;
816 EVAL_CXX (OP_CEQ,==,gint32)
817 EVAL_CXX (OP_CGT,>,gint32)
818 EVAL_CXX (OP_CGT_UN,>,guint32)
819 EVAL_CXX (OP_CLT,<,gint32)
820 EVAL_CXX (OP_CLT_UN,<,guint32)
822 EVAL_BINOP (CEE_ADD,+)
823 EVAL_BINOP (CEE_SUB,-)
824 EVAL_BINOP (CEE_MUL,*)
825 EVAL_BINOP (CEE_AND,&)
826 EVAL_BINOP (CEE_OR,|)
827 EVAL_BINOP (CEE_XOR,^)
828 EVAL_BINOP (CEE_SHL,<<)
829 EVAL_BINOP (CEE_SHR,>>)
839 fold_tree (MonoCompile *cfg, MonoBasicBlock *bb, MonoInst *inst, MonoInst **carray)
847 arity = mono_burg_arity [inst->opcode];
849 if (inst->ssa_op == MONO_SSA_STORE &&
850 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG) &&
851 inst->inst_i1->opcode == OP_PHI && (c0 = carray [inst->inst_i0->inst_c0])) {
852 //{static int cn = 0; printf ("PHICONST %d %d %s\n", cn++, c0->inst_c0, mono_method_full_name (cfg->method, TRUE));}
853 *inst->inst_i1 = *c0;
854 } else if (inst->ssa_op == MONO_SSA_LOAD &&
855 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG) &&
856 (c0 = carray [inst->inst_i0->inst_c0])) {
857 //{static int cn = 0; printf ("YCCOPY %d %d %s\n", cn++, c0->inst_c0, mono_method_full_name (cfg->method, TRUE));}
862 fold_tree (cfg, bb, inst->inst_left, carray);
864 fold_tree (cfg, bb, inst->inst_right, carray);
865 mono_constant_fold_inst (inst, NULL);
869 if ((inst->opcode >= CEE_BEQ && inst->opcode <= CEE_BLT_UN) &&
870 inst->inst_i0->opcode == OP_COMPARE) {
871 MonoInst *v0 = inst->inst_i0->inst_i0;
872 MonoInst *v1 = inst->inst_i0->inst_i1;
873 MonoBasicBlock *target = NULL;
875 /* hack for longs to optimize the simply cases */
876 if (v0->opcode == OP_I8CONST && v1->opcode == OP_I8CONST) {
877 if (simulate_long_compare (inst->opcode, v0->inst_l, v1->inst_l)) {
878 //unlink_target (bb, inst->inst_false_bb);
879 target = inst->inst_true_bb;
881 //unlink_target (bb, inst->inst_true_bb);
882 target = inst->inst_false_bb;
884 } else if (evaluate_const_tree (cfg, v0, &a, carray) == 1 &&
885 evaluate_const_tree (cfg, v1, &b, carray) == 1) {
886 if (simulate_compare (inst->opcode, a, b)) {
887 //unlink_target (bb, inst->inst_false_bb);
888 target = inst->inst_true_bb;
890 //unlink_target (bb, inst->inst_true_bb);
891 target = inst->inst_false_bb;
896 bb->out_bb [0] = target;
898 inst->opcode = CEE_BR;
899 inst->inst_target_bb = target;
901 } else if (inst->opcode == CEE_SWITCH && evaluate_const_tree (cfg, inst->inst_left, &a, carray) == 1) {
902 bb->out_bb [0] = inst->inst_many_bb [a];
904 inst->inst_target_bb = bb->out_bb [0];
905 inst->opcode = CEE_BR;
911 change_varstate (MonoCompile *cfg, GList **cvars, MonoMethodVar *info, int state, MonoInst *c0, MonoInst **carray)
913 if (info->cpstate >= state)
916 info->cpstate = state;
918 //printf ("SETSTATE %d to %d\n", info->idx, info->cpstate);
921 carray [info->idx] = c0;
923 carray [info->idx] = NULL;
925 if (!g_list_find (*cvars, info)) {
926 *cvars = g_list_prepend (*cvars, info);
931 visit_inst (MonoCompile *cfg, MonoBasicBlock *bb, MonoInst *inst, GList **cvars, GList **bblist, MonoInst **carray)
935 if (inst->opcode == CEE_SWITCH) {
938 r1 = evaluate_const_tree (cfg, inst->inst_left, &a, carray);
940 MonoBasicBlock *tb = inst->inst_many_bb [a];
941 if (!(tb->flags & BB_REACHABLE)) {
942 tb->flags |= BB_REACHABLE;
943 *bblist = g_list_prepend (*bblist, tb);
945 } else if (r1 == 2) {
946 for (i = (int)inst->klass; i >= 0; i--) {
947 MonoBasicBlock *tb = inst->inst_many_bb [i];
948 if (!(tb->flags & BB_REACHABLE)) {
949 tb->flags |= BB_REACHABLE;
950 *bblist = g_list_prepend (*bblist, tb);
954 } else if ((inst->opcode >= CEE_BEQ && inst->opcode <= CEE_BLT_UN) &&
955 inst->inst_i0->opcode == OP_COMPARE) {
957 MonoInst *v0 = inst->inst_i0->inst_i0;
958 MonoInst *v1 = inst->inst_i0->inst_i1;
960 r1 = evaluate_const_tree (cfg, v0, &a, carray);
961 r2 = evaluate_const_tree (cfg, v1, &b, carray);
963 if (r1 == 1 && r2 == 1) {
964 MonoBasicBlock *target;
966 if (simulate_compare (inst->opcode, a, b)) {
967 target = inst->inst_true_bb;
969 target = inst->inst_false_bb;
971 if (!(target->flags & BB_REACHABLE)) {
972 target->flags |= BB_REACHABLE;
973 *bblist = g_list_prepend (*bblist, target);
975 } else if (r1 == 2 || r2 == 2) {
976 if (!(inst->inst_true_bb->flags & BB_REACHABLE)) {
977 inst->inst_true_bb->flags |= BB_REACHABLE;
978 *bblist = g_list_prepend (*bblist, inst->inst_true_bb);
980 if (!(inst->inst_false_bb->flags & BB_REACHABLE)) {
981 inst->inst_false_bb->flags |= BB_REACHABLE;
982 *bblist = g_list_prepend (*bblist, inst->inst_false_bb);
985 } else if (inst->ssa_op == MONO_SSA_STORE &&
986 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG)) {
987 MonoMethodVar *info = cfg->vars [inst->inst_i0->inst_c0];
988 MonoInst *i1 = inst->inst_i1;
991 if (info->cpstate < 2) {
992 if (i1->opcode == OP_ICONST) {
993 change_varstate (cfg, cvars, info, 1, i1, carray);
994 } else if (i1->opcode == OP_PHI) {
998 for (j = 1; j <= i1->inst_phi_args [0]; j++) {
999 MonoMethodVar *mv = cfg->vars [i1->inst_phi_args [j]];
1000 MonoInst *src = mv->def;
1002 if (mv->def_bb && !(mv->def_bb->flags & BB_REACHABLE)) {
1006 if (!mv->def || !src || src->ssa_op != MONO_SSA_STORE ||
1007 !(src->inst_i0->opcode == OP_LOCAL || src->inst_i0->opcode == OP_ARG) ||
1009 change_varstate (cfg, cvars, info, 2, NULL, carray);
1013 if (mv->cpstate == 0)
1016 //g_assert (src->inst_i1->opcode == OP_ICONST);
1017 g_assert (carray [mv->idx]);
1020 c0 = carray [mv->idx];
1023 if (carray [mv->idx]->inst_c0 != c0->inst_c0) {
1024 change_varstate (cfg, cvars, info, 2, NULL, carray);
1029 if (c0 && info->cpstate < 1) {
1030 change_varstate (cfg, cvars, info, 1, c0, carray);
1033 int state = evaluate_const_tree (cfg, i1, &res, carray);
1035 NEW_ICONST (cfg, i1, res);
1036 change_varstate (cfg, cvars, info, 1, i1, carray);
1038 change_varstate (cfg, cvars, info, 2, NULL, carray);
1046 mono_ssa_cprop (MonoCompile *cfg)
1050 GList *bblock_list, *cvars;
1053 //printf ("SIMPLE OPTS BB%d %s\n", bb->block_num, mono_method_full_name (cfg->method, TRUE));
1055 carray = g_new0 (MonoInst*, cfg->num_varinfo);
1057 if (!(cfg->comp_done & MONO_COMP_SSA_DEF_USE))
1058 mono_ssa_create_def_use (cfg);
1060 bblock_list = g_list_prepend (NULL, cfg->bb_entry);
1061 cfg->bb_entry->flags |= BB_REACHABLE;
1063 memset (carray, 0, sizeof (MonoInst *) * cfg->num_varinfo);
1065 for (i = 0; i < cfg->num_varinfo; i++) {
1066 MonoMethodVar *info = cfg->vars [i];
1073 while (bblock_list) {
1076 bb = (MonoBasicBlock *)bblock_list->data;
1078 bblock_list = g_list_remove_link (bblock_list, bblock_list);
1080 g_assert (bb->flags & BB_REACHABLE);
1082 if (bb->out_count == 1) {
1083 if (!(bb->out_bb [0]->flags & BB_REACHABLE)) {
1084 bb->out_bb [0]->flags |= BB_REACHABLE;
1085 bblock_list = g_list_prepend (bblock_list, bb->out_bb [0]);
1089 for (inst = bb->code; inst; inst = inst->next) {
1090 visit_inst (cfg, bb, inst, &cvars, &bblock_list, carray);
1094 MonoMethodVar *info = (MonoMethodVar *)cvars->data;
1095 cvars = g_list_remove_link (cvars, cvars);
1097 for (tmp = info->uses; tmp; tmp = tmp->next) {
1098 MonoVarUsageInfo *ui = (MonoVarUsageInfo *)tmp->data;
1099 if (!(ui->bb->flags & BB_REACHABLE))
1101 visit_inst (cfg, ui->bb, ui->inst, &cvars, &bblock_list, carray);
1106 for (bb = cfg->bb_entry->next_bb; bb; bb = bb->next_bb) {
1108 for (inst = bb->code; inst; inst = inst->next) {
1109 fold_tree (cfg, bb, inst, carray);
1115 cfg->comp_done |= MONO_COMP_REACHABILITY;
1119 add_to_dce_worklist (MonoCompile *cfg, MonoMethodVar *var, MonoMethodVar *use, GList **wl)
1123 *wl = g_list_prepend (*wl, use);
1125 for (tmp = use->uses; tmp; tmp = tmp->next) {
1126 MonoVarUsageInfo *ui = (MonoVarUsageInfo *)tmp->data;
1127 if (ui->inst == var->def) {
1128 use->uses = g_list_remove_link (use->uses, tmp);
1135 mono_ssa_deadce (MonoCompile *cfg)
1140 g_assert (cfg->comp_done & MONO_COMP_SSA);
1142 //printf ("DEADCE %s\n", mono_method_full_name (cfg->method, TRUE));
1144 /* fixme: we should update usage infos during cprop, instead of computing it again */
1145 cfg->comp_done &= ~MONO_COMP_SSA_DEF_USE;
1146 for (i = 0; i < cfg->num_varinfo; i++) {
1147 MonoMethodVar *info = cfg->vars [i];
1152 if (!(cfg->comp_done & MONO_COMP_SSA_DEF_USE))
1153 mono_ssa_create_def_use (cfg);
1155 mono_ssa_avoid_copies (cfg);
1158 for (i = 0; i < cfg->num_varinfo; i++) {
1159 MonoMethodVar *info = cfg->vars [i];
1160 work_list = g_list_prepend (work_list, info);
1164 MonoMethodVar *info = (MonoMethodVar *)work_list->data;
1165 work_list = g_list_remove_link (work_list, work_list);
1167 if (!info->uses && info->def) {
1169 //printf ("ELIMINATE %s: ", mono_method_full_name (cfg->method, TRUE)); mono_print_tree (info->def); printf ("\n");
1171 i1 = info->def->inst_i1;
1172 if (i1->opcode == OP_PHI) {
1174 for (j = i1->inst_phi_args [0]; j > 0; j--) {
1175 MonoMethodVar *u = cfg->vars [i1->inst_phi_args [j]];
1176 add_to_dce_worklist (cfg, info, u, &work_list);
1178 } else if (i1->ssa_op == MONO_SSA_LOAD &&
1179 (i1->inst_i0->opcode == OP_LOCAL || i1->inst_i0->opcode == OP_ARG)) {
1180 MonoMethodVar *u = cfg->vars [i1->inst_i0->inst_c0];
1181 add_to_dce_worklist (cfg, info, u, &work_list);
1184 info->def->opcode = CEE_NOP;
1185 info->def->ssa_op = MONO_SSA_NOP;
1193 mono_ssa_strength_reduction (MonoCompile *cfg)
1198 g_assert (cfg->comp_done & MONO_COMP_SSA);
1199 g_assert (cfg->comp_done & MONO_COMP_LOOPS);
1200 g_assert (cfg->comp_done & MONO_COMP_SSA_DEF_USE);
1202 for (bb = cfg->bb_entry->next_bb; bb; bb = bb->next_bb) {
1203 GList *lp = bb->loop_blocks;
1206 MonoBasicBlock *h = (MonoBasicBlock *)lp->data;
1208 /* we only consider loops with 2 in bblocks */
1209 if (!h->in_count == 2)
1212 for (i = 0; i < cfg->num_varinfo; i++) {
1213 MonoMethodVar *info = cfg->vars [i];
1215 if (info->def && info->def->ssa_op == MONO_SSA_STORE &&
1216 info->def->inst_i0->opcode == OP_LOCAL && g_list_find (lp, info->def_bb)) {
1217 MonoInst *v = info->def->inst_i1;
1220 printf ("FOUND %d in %s\n", info->idx, mono_method_full_name (cfg->method, TRUE));