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 mono_bitset_foreach_bit (set, idx, cfg->num_bblocks) {
316 MonoBasicBlock *bb = cfg->bblocks [idx];
318 /* fixme: create pruned SSA? we would need liveness information for that */
320 if (bb == cfg->bb_exit)
323 if ((cfg->comp_done & MONO_COMP_LIVENESS) && !mono_bitset_test_fast (bb->live_in_set, i)) {
324 //printf ("%d is not live in BB%d %s\n", i, bb->block_num, mono_method_full_name (cfg->method, TRUE));
328 NEW_PHI (cfg, inst, i);
330 inst->inst_phi_args = mono_mempool_alloc0 (cfg->mempool, sizeof (int) * (cfg->bblocks [idx]->in_count + 1));
331 inst->inst_phi_args [0] = cfg->bblocks [idx]->in_count;
333 store = mono_mempool_alloc0 ((cfg)->mempool, sizeof (MonoInst));
334 if (!cfg->varinfo [i]->inst_vtype->type)
335 g_assert_not_reached ();
336 store->opcode = mono_type_to_stind (cfg->varinfo [i]->inst_vtype);
337 store->ssa_op = MONO_SSA_STORE;
338 store->inst_i0 = cfg->varinfo [i];
339 store->inst_i1 = inst;
340 store->klass = store->inst_i0->klass;
342 store->next = bb->code;
345 bb->last_ins = bb->code;
348 printf ("ADD PHI BB%d %s\n", cfg->bblocks [idx]->block_num, mono_method_full_name (cfg->method, TRUE));
354 for (i = 0; i < cfg->num_varinfo; ++i)
355 mono_bitset_free (vinfo [i].def_in);
359 stack = alloca (sizeof (MonoInst *) * cfg->num_varinfo);
361 for (i = 0; i < cfg->num_varinfo; i++)
364 mono_ssa_rename_vars (cfg, cfg->num_varinfo, cfg->bb_entry, stack);
366 cfg->comp_done |= MONO_COMP_SSA;
369 #ifndef USE_ORIGINAL_VARS
371 mono_ssa_get_allocatable_vars (MonoCompile *cfg)
373 GHashTable *type_hash;
374 GPtrArray *varlist_array = g_ptr_array_new ();
377 g_assert (cfg->comp_done & MONO_COMP_LIVENESS);
379 type_hash = g_hash_table_new (NULL, NULL);
381 for (i = 0; i < cfg->num_varinfo; i++) {
382 MonoInst *ins = cfg->varinfo [i];
383 MonoMethodVar *vmv = MONO_VARINFO (cfg, i);
386 if (vmv->range.first_use.abs_pos > vmv->range.last_use.abs_pos)
389 if (ins->flags & (MONO_INST_VOLATILE|MONO_INST_INDIRECT) ||
390 (ins->opcode != OP_LOCAL && ins->opcode != OP_ARG) || vmv->reg != -1)
393 g_assert (ins->inst_vtype);
394 g_assert (vmv->reg == -1);
395 g_assert (i == vmv->idx);
397 if (!(tidx = (int)g_hash_table_lookup (type_hash, ins->inst_vtype))) {
398 GList *vars = g_list_append (NULL, vmv);
399 g_ptr_array_add (varlist_array, vars);
400 g_hash_table_insert (type_hash, ins->inst_vtype, (gpointer)varlist_array->len);
403 g_ptr_array_index (varlist_array, tidx) =
404 mono_varlist_insert_sorted (cfg, g_ptr_array_index (varlist_array, tidx), vmv, FALSE);
408 g_hash_table_destroy (type_hash);
410 return varlist_array;
415 mono_ssa_replace_copies (MonoCompile *cfg, MonoBasicBlock *bb, MonoInst *inst, char *is_live)
422 arity = mono_burg_arity [inst->opcode];
424 if ((inst->ssa_op == MONO_SSA_LOAD || inst->ssa_op == MONO_SSA_ADDRESS_TAKEN || inst->ssa_op == MONO_SSA_STORE) &&
425 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG)) {
427 int idx = inst->inst_i0->inst_c0;
428 MonoMethodVar *mv = MONO_VARINFO (cfg, idx);
430 if (mv->reg != -1 && mv->reg != mv->idx) {
432 is_live [mv->reg] = 1;
434 new_var = cfg->varinfo [mv->reg];
437 printf ("REPLACE COPY BB%d %d %d\n", bb->block_num, idx, new_var->inst_c0);
438 g_assert (cfg->varinfo [mv->reg]->inst_vtype == cfg->varinfo [idx]->inst_vtype);
440 inst->inst_p0 = new_var;
442 is_live [mv->idx] = 1;
448 mono_ssa_replace_copies (cfg, bb, inst->inst_left, is_live);
450 mono_ssa_replace_copies (cfg, bb, inst->inst_right, is_live);
453 if (inst->ssa_op == MONO_SSA_STORE && inst->inst_i1->ssa_op == MONO_SSA_LOAD &&
454 inst->inst_i0->inst_c0 == inst->inst_i1->inst_i0->inst_c0) {
455 inst->ssa_op = MONO_SSA_NOP;
456 inst->opcode = OP_NOP;
462 mono_ssa_remove (MonoCompile *cfg)
464 MonoInst *inst, *phi;
467 #ifndef USE_ORIGINAL_VARS
468 GPtrArray *varlist_array;
471 g_assert (cfg->comp_done & MONO_COMP_SSA);
473 for (i = 0; i < cfg->num_bblocks; ++i) {
474 MonoBasicBlock *bb = cfg->bblocks [i];
475 MONO_BB_FOR_EACH_INS (bb, inst) {
476 if (inst->ssa_op == MONO_SSA_STORE && inst->inst_i1->opcode == OP_PHI) {
479 g_assert (phi->inst_phi_args [0] == bb->in_count);
481 for (j = 0; j < bb->in_count; j++) {
482 MonoBasicBlock *pred = bb->in_bb [j];
483 int idx = phi->inst_phi_args [j + 1];
484 MonoMethodVar *mv = MONO_VARINFO (cfg, idx);
486 if (mv->reg != -1 && mv->reg != mv->idx) {
487 //printf ("PHICOPY %d %d -> %d\n", idx, mv->reg, inst->inst_i0->inst_c0);
492 if (idx != inst->inst_i0->inst_c0) {
494 printf ("MOVE %d to %d in BB%d\n", idx, inst->inst_i0->inst_c0, pred->block_num);
496 mono_add_varcopy_to_end (cfg, pred, idx, inst->inst_i0->inst_c0);
500 /* remove the phi functions */
501 inst->opcode = OP_NOP;
502 inst->ssa_op = MONO_SSA_NOP;
507 #ifndef USE_ORIGINAL_VARS
508 /* we compute liveness again */
509 cfg->comp_done &= ~MONO_COMP_LIVENESS;
510 mono_analyze_liveness (cfg);
512 varlist_array = mono_ssa_get_allocatable_vars (cfg);
514 for (i = 0; i < varlist_array->len; i++) {
515 GList *l, *regs, *vars = g_ptr_array_index (varlist_array, i);
516 MonoMethodVar *vmv, *amv;
518 if (g_list_length (vars) <= 1) {
525 for (l = vars; l; l = l->next) {
528 /* expire old intervals in active */
530 amv = (MonoMethodVar *)active->data;
532 if (amv->range.last_use.abs_pos >= vmv->range.first_use.abs_pos)
535 active = g_list_delete_link (active, active);
536 regs = g_list_prepend (regs, (gpointer)amv->reg);
540 regs = g_list_prepend (regs, (gpointer)vmv->idx);
542 vmv->reg = (int)regs->data;
543 regs = g_list_delete_link (regs, regs);
544 active = mono_varlist_insert_sorted (cfg, active, vmv, TRUE);
547 g_list_free (active);
552 g_ptr_array_free (varlist_array, TRUE);
556 is_live = alloca (cfg->num_varinfo);
557 memset (is_live, 0, cfg->num_varinfo);
559 for (i = 0; i < cfg->num_bblocks; ++i) {
560 MonoBasicBlock *bb = cfg->bblocks [i];
562 MONO_BB_FOR_EACH_INS (bb, inst)
563 mono_ssa_replace_copies (cfg, bb, inst, is_live);
566 for (i = 0; i < cfg->num_varinfo; ++i) {
567 MONO_VARINFO (cfg, i)->reg = -1;
568 if (!is_live [i] && !(cfg->varinfo [i]->flags & MONO_INST_VOLATILE)) {
569 cfg->varinfo [i]->flags |= MONO_INST_IS_DEAD;
573 if (cfg->comp_done & MONO_COMP_REACHABILITY)
574 unlink_unused_bblocks (cfg);
576 cfg->comp_done &= ~MONO_COMP_SSA;
580 #define IS_CALL(op) (op == CEE_CALLI || op == OP_CALL || op == OP_CALLVIRT || (op >= OP_VOIDCALL && op <= OP_CALL_MEMBASE))
591 * Returns TRUE if the tree can have side effects.
594 analyze_dev_use (MonoCompile *cfg, MonoBasicBlock *bb, MonoInst *root, MonoInst *inst)
598 gboolean has_side_effects;
603 arity = mono_burg_arity [inst->opcode];
604 switch (inst->opcode) {
605 #define ANALYZE_DEV_USE_SPECIFIC_OPS 1
606 #define OPDEF(a1,a2,a3,a4,a5,a6,a7,a8,a9,a10) case a1:
607 #include "simple-cee-ops.h"
609 #define MINI_OP(a1,a2) case a1:
610 #include "simple-mini-ops.h"
612 #undef ANALYZE_DEV_USE_SPECIFIC_OPS
613 has_side_effects = FALSE;
616 has_side_effects = TRUE;
619 if ((inst->ssa_op == MONO_SSA_STORE) &&
620 (inst->inst_i0->opcode == OP_LOCAL /*|| inst->inst_i0->opcode == OP_ARG */)) {
621 idx = inst->inst_i0->inst_c0;
622 info = MONO_VARINFO (cfg, idx);
623 //printf ("%d defined in BB%d %p\n", idx, bb->block_num, root);
625 g_warning ("more than one definition of variable %d in %s", idx,
626 mono_method_full_name (cfg->method, TRUE));
627 g_assert_not_reached ();
629 if (!IS_CALL (inst->inst_i1->opcode) /* && inst->inst_i1->opcode == OP_ICONST */) {
630 g_assert (inst == root);
635 if (inst->inst_i1->opcode == OP_PHI) {
636 for (i = inst->inst_i1->inst_phi_args [0]; i > 0; i--) {
637 MonoVarUsageInfo *ui = mono_mempool_alloc (cfg->mempool, sizeof (MonoVarUsageInfo));
638 idx = inst->inst_i1->inst_phi_args [i];
639 info = MONO_VARINFO (cfg, idx);
640 //printf ("FOUND %d\n", idx);
643 info->uses = g_list_prepend_mempool (info->uses, cfg->mempool, ui);
648 if ((inst->ssa_op == MONO_SSA_LOAD || inst->ssa_op == MONO_SSA_ADDRESS_TAKEN) &&
649 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG)) {
650 MonoVarUsageInfo *ui = mono_mempool_alloc (cfg->mempool, sizeof (MonoVarUsageInfo));
651 idx = inst->inst_i0->inst_c0;
652 info = MONO_VARINFO (cfg, idx);
653 //printf ("FOUND %d\n", idx);
656 info->uses = g_list_prepend_mempool (info->uses, cfg->mempool, ui);
659 //if (inst->ssa_op != MONO_SSA_STORE)
660 if (analyze_dev_use (cfg, bb, root, inst->inst_left))
661 has_side_effects = TRUE;
663 if (analyze_dev_use (cfg, bb, root, inst->inst_right))
664 has_side_effects = TRUE;
668 return has_side_effects;
672 /* avoid unnecessary copies of variables:
673 * Y <= X; Z = Y; is translated to Z = X;
676 mono_ssa_avoid_copies (MonoCompile *cfg)
678 MonoInst *inst, *next;
680 MonoMethodVar *i1, *i2;
682 g_assert ((cfg->comp_done & MONO_COMP_SSA_DEF_USE));
684 for (bb = cfg->bb_entry; bb; bb = bb->next_bb) {
685 MONO_BB_FOR_EACH_INS (bb, inst) {
686 if (inst->ssa_op == MONO_SSA_STORE && inst->inst_i0->opcode == OP_LOCAL &&
687 !IS_CALL (inst->inst_i1->opcode) && inst->inst_i1->opcode != OP_PHI && !inst->flags) {
688 i1 = MONO_VARINFO (cfg, inst->inst_i0->inst_c0);
690 /* fixme: compiling mcs does not work when I enable this */
692 if (g_list_length (i1->uses) == 1 && !extends_live (inst->inst_i1)) {
693 MonoVarUsageInfo *vi = (MonoVarUsageInfo *)i1->uses->data;
696 //printf ("VAR %d %s\n", i1->idx, mono_method_full_name (cfg->method, TRUE));
697 //mono_print_tree (inst); printf ("\n");
698 //mono_print_tree (u); printf ("\n");
700 if (replace_usage_new (cfg, u, inst->inst_i0->inst_c0, inst->inst_i1)) {
702 //mono_print_tree (u); printf ("\n");
704 inst->opcode = OP_NOP;
705 inst->ssa_op = MONO_SSA_NOP;
710 if (next && next->ssa_op == MONO_SSA_STORE &&
711 next->inst_i0->opcode == OP_LOCAL &&
712 next->inst_i1->ssa_op == MONO_SSA_LOAD &&
713 next->inst_i1->inst_i0->opcode == OP_LOCAL &&
714 next->inst_i1->inst_i0->inst_c0 == inst->inst_i0->inst_c0 &&
715 g_list_length (i1->uses) == 1 &&
716 inst->opcode == next->opcode &&
717 inst->inst_i0->type == next->inst_i0->type) {
718 i2 = MONO_VARINFO (cfg, next->inst_i0->inst_c0);
719 //printf ("ELIM. COPY in BB%d %s\n", bb->block_num, mono_method_full_name (cfg->method, TRUE));
720 inst->inst_i0 = next->inst_i0;
724 next->opcode = OP_NOP;
725 next->ssa_op = MONO_SSA_NOP;
733 mono_ssa_create_def_use (MonoCompile *cfg)
737 g_assert (!(cfg->comp_done & MONO_COMP_SSA_DEF_USE));
739 for (bb = cfg->bb_entry; bb; bb = bb->next_bb) {
741 MONO_BB_FOR_EACH_INS (bb, inst) {
742 gboolean has_side_effects = analyze_dev_use (cfg, bb, inst, inst);
743 if (has_side_effects && (inst->ssa_op == MONO_SSA_STORE) &&
744 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG)) {
745 inst->inst_i0->flags |= MONO_INST_DEFINITION_HAS_SIDE_EFFECTS;
750 cfg->comp_done |= MONO_COMP_SSA_DEF_USE;
754 simulate_compare (int opcode, int a, int b)
770 return (unsigned)a >= (unsigned)b;
772 return (unsigned)a > (unsigned)b;
774 return (unsigned)a <= (unsigned)b;
776 return (unsigned)a < (unsigned)b;
778 g_assert_not_reached ();
785 simulate_long_compare (int opcode, gint64 a, gint64 b)
801 return (guint64)a >= (guint64)b;
803 return (guint64)a > (guint64)b;
805 return (guint64)a <= (guint64)b;
807 return (guint64)a < (guint64)b;
809 g_assert_not_reached ();
815 #define EVAL_CXX(name,op,cast) \
817 if ((inst->inst_i0->opcode == OP_COMPARE) || (inst->inst_i0->opcode == OP_LCOMPARE)) { \
818 r1 = evaluate_const_tree (cfg, inst->inst_i0->inst_i0, &a, carray); \
819 r2 = evaluate_const_tree (cfg, inst->inst_i0->inst_i1, &b, carray); \
820 if (r1 == 1 && r2 == 1) { \
821 *res = ((cast)a op (cast)b); \
824 return MAX (r1, r2); \
829 #define EVAL_BINOP(name,op) \
831 r1 = evaluate_const_tree (cfg, inst->inst_i0, &a, carray); \
832 r2 = evaluate_const_tree (cfg, inst->inst_i1, &b, carray); \
833 if (r1 == 1 && r2 == 1) { \
837 return MAX (r1, r2); \
842 /* fixme: this only works for interger constants, but not for other types (long, float) */
844 evaluate_const_tree (MonoCompile *cfg, MonoInst *inst, int *res, MonoInst **carray)
852 if (inst->ssa_op == MONO_SSA_LOAD &&
853 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG) &&
854 (c0 = carray [inst->inst_i0->inst_c0])) {
859 switch (inst->opcode) {
861 *res = inst->inst_c0;
864 EVAL_CXX (OP_CEQ,==,gint32)
865 EVAL_CXX (OP_CGT,>,gint32)
866 EVAL_CXX (OP_CGT_UN,>,guint32)
867 EVAL_CXX (OP_CLT,<,gint32)
868 EVAL_CXX (OP_CLT_UN,<,guint32)
870 EVAL_BINOP (CEE_ADD,+)
871 EVAL_BINOP (CEE_SUB,-)
872 EVAL_BINOP (CEE_MUL,*)
873 EVAL_BINOP (CEE_AND,&)
874 EVAL_BINOP (CEE_OR,|)
875 EVAL_BINOP (CEE_XOR,^)
876 EVAL_BINOP (CEE_SHL,<<)
877 EVAL_BINOP (CEE_SHR,>>)
887 fold_tree (MonoCompile *cfg, MonoBasicBlock *bb, MonoInst *inst, MonoInst **carray)
895 arity = mono_burg_arity [inst->opcode];
897 if (inst->ssa_op == MONO_SSA_STORE &&
898 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG) &&
899 inst->inst_i1->opcode == OP_PHI && (c0 = carray [inst->inst_i0->inst_c0])) {
900 //{static int cn = 0; printf ("PHICONST %d %d %s\n", cn++, c0->inst_c0, mono_method_full_name (cfg->method, TRUE));}
901 *inst->inst_i1 = *c0;
902 } else if (inst->ssa_op == MONO_SSA_LOAD &&
903 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG) &&
904 (c0 = carray [inst->inst_i0->inst_c0])) {
905 //{static int cn = 0; printf ("YCCOPY %d %d %s\n", cn++, c0->inst_c0, mono_method_full_name (cfg->method, TRUE));}
910 fold_tree (cfg, bb, inst->inst_left, carray);
912 fold_tree (cfg, bb, inst->inst_right, carray);
913 mono_constant_fold_inst (inst, NULL);
917 if ((inst->opcode >= CEE_BEQ && inst->opcode <= CEE_BLT_UN) &&
918 ((inst->inst_i0->opcode == OP_COMPARE) || (inst->inst_i0->opcode == OP_LCOMPARE))) {
919 MonoInst *v0 = inst->inst_i0->inst_i0;
920 MonoInst *v1 = inst->inst_i0->inst_i1;
921 MonoBasicBlock *target = NULL;
923 /* hack for longs to optimize the simply cases */
924 if (v0->opcode == OP_I8CONST && v1->opcode == OP_I8CONST) {
925 if (simulate_long_compare (inst->opcode, v0->inst_l, v1->inst_l)) {
926 //unlink_target (bb, inst->inst_false_bb);
927 target = inst->inst_true_bb;
929 //unlink_target (bb, inst->inst_true_bb);
930 target = inst->inst_false_bb;
932 } else if (evaluate_const_tree (cfg, v0, &a, carray) == 1 &&
933 evaluate_const_tree (cfg, v1, &b, carray) == 1) {
934 if (simulate_compare (inst->opcode, a, b)) {
935 //unlink_target (bb, inst->inst_false_bb);
936 target = inst->inst_true_bb;
938 //unlink_target (bb, inst->inst_true_bb);
939 target = inst->inst_false_bb;
944 bb->out_bb [0] = target;
946 inst->opcode = OP_BR;
947 inst->inst_target_bb = target;
949 } else if (inst->opcode == OP_SWITCH && (evaluate_const_tree (cfg, inst->inst_left, &a, carray) == 1) && (a >= 0) && (a < GPOINTER_TO_INT (inst->klass))) {
950 bb->out_bb [0] = inst->inst_many_bb [a];
952 inst->inst_target_bb = bb->out_bb [0];
953 inst->opcode = OP_BR;
959 change_varstate (MonoCompile *cfg, GList **cvars, MonoMethodVar *info, int state, MonoInst *c0, MonoInst **carray)
961 if (info->cpstate >= state)
964 info->cpstate = state;
966 //printf ("SETSTATE %d to %d\n", info->idx, info->cpstate);
969 carray [info->idx] = c0;
971 carray [info->idx] = NULL;
973 if (!g_list_find (*cvars, info)) {
974 *cvars = g_list_prepend (*cvars, info);
979 visit_inst (MonoCompile *cfg, MonoBasicBlock *bb, MonoInst *inst, GList **cvars, GList **bblist, MonoInst **carray)
983 if (inst->opcode == OP_SWITCH) {
985 int cases = GPOINTER_TO_INT (inst->klass);
987 r1 = evaluate_const_tree (cfg, inst->inst_left, &a, carray);
988 if ((r1 == 1) && ((a < 0) || (a >= cases)))
991 MonoBasicBlock *tb = inst->inst_many_bb [a];
992 if (!(tb->flags & BB_REACHABLE)) {
993 tb->flags |= BB_REACHABLE;
994 *bblist = g_list_prepend (*bblist, tb);
996 } else if (r1 == 2) {
997 for (i = GPOINTER_TO_INT (inst->klass); i >= 0; i--) {
998 MonoBasicBlock *tb = inst->inst_many_bb [i];
999 if (!(tb->flags & BB_REACHABLE)) {
1000 tb->flags |= BB_REACHABLE;
1001 *bblist = g_list_prepend (*bblist, tb);
1005 } else if (inst->opcode == OP_BR) {
1006 MonoBasicBlock *target = inst->inst_target_bb;
1008 if (!(target->flags & BB_REACHABLE)) {
1009 target->flags |= BB_REACHABLE;
1010 *bblist = g_list_prepend (*bblist, target);
1012 } else if ((inst->opcode >= CEE_BEQ && inst->opcode <= CEE_BLT_UN) &&
1013 ((inst->inst_i0->opcode == OP_COMPARE) || (inst->inst_i0->opcode == OP_LCOMPARE))) {
1015 MonoInst *v0 = inst->inst_i0->inst_i0;
1016 MonoInst *v1 = inst->inst_i0->inst_i1;
1018 r1 = evaluate_const_tree (cfg, v0, &a, carray);
1019 r2 = evaluate_const_tree (cfg, v1, &b, carray);
1021 if (r1 == 1 && r2 == 1) {
1022 MonoBasicBlock *target;
1024 if (simulate_compare (inst->opcode, a, b)) {
1025 target = inst->inst_true_bb;
1027 target = inst->inst_false_bb;
1029 if (!(target->flags & BB_REACHABLE)) {
1030 target->flags |= BB_REACHABLE;
1031 *bblist = g_list_prepend (*bblist, target);
1033 } else if (r1 == 2 || r2 == 2) {
1034 if (!(inst->inst_true_bb->flags & BB_REACHABLE)) {
1035 inst->inst_true_bb->flags |= BB_REACHABLE;
1036 *bblist = g_list_prepend (*bblist, inst->inst_true_bb);
1038 if (!(inst->inst_false_bb->flags & BB_REACHABLE)) {
1039 inst->inst_false_bb->flags |= BB_REACHABLE;
1040 *bblist = g_list_prepend (*bblist, inst->inst_false_bb);
1043 } else if (inst->ssa_op == MONO_SSA_STORE &&
1044 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG)) {
1045 MonoMethodVar *info = MONO_VARINFO (cfg, inst->inst_i0->inst_c0);
1046 MonoInst *i1 = inst->inst_i1;
1049 if (info->cpstate < 2) {
1050 if (i1->opcode == OP_ICONST) {
1051 change_varstate (cfg, cvars, info, 1, i1, carray);
1052 } else if (i1->opcode == OP_PHI) {
1053 MonoInst *c0 = NULL;
1056 for (j = 1; j <= i1->inst_phi_args [0]; j++) {
1057 MonoMethodVar *mv = MONO_VARINFO (cfg, i1->inst_phi_args [j]);
1058 MonoInst *src = mv->def;
1060 if (mv->def_bb && !(mv->def_bb->flags & BB_REACHABLE)) {
1064 if (!mv->def || !src || src->ssa_op != MONO_SSA_STORE ||
1065 !(src->inst_i0->opcode == OP_LOCAL || src->inst_i0->opcode == OP_ARG) ||
1067 change_varstate (cfg, cvars, info, 2, NULL, carray);
1071 if (mv->cpstate == 0)
1074 //g_assert (src->inst_i1->opcode == OP_ICONST);
1075 g_assert (carray [mv->idx]);
1078 c0 = carray [mv->idx];
1081 if (carray [mv->idx]->inst_c0 != c0->inst_c0) {
1082 change_varstate (cfg, cvars, info, 2, NULL, carray);
1087 if (c0 && info->cpstate < 1) {
1088 change_varstate (cfg, cvars, info, 1, c0, carray);
1091 int state = evaluate_const_tree (cfg, i1, &res, carray);
1093 NEW_ICONST (cfg, i1, res);
1094 change_varstate (cfg, cvars, info, 1, i1, carray);
1096 change_varstate (cfg, cvars, info, 2, NULL, carray);
1104 mono_ssa_cprop (MonoCompile *cfg)
1108 GList *bblock_list, *cvars;
1111 //printf ("SIMPLE OPTS BB%d %s\n", bb->block_num, mono_method_full_name (cfg->method, TRUE));
1113 carray = g_new0 (MonoInst*, cfg->num_varinfo);
1115 if (!(cfg->comp_done & MONO_COMP_SSA_DEF_USE))
1116 mono_ssa_create_def_use (cfg);
1118 bblock_list = g_list_prepend (NULL, cfg->bb_entry);
1119 cfg->bb_entry->flags |= BB_REACHABLE;
1121 memset (carray, 0, sizeof (MonoInst *) * cfg->num_varinfo);
1123 for (i = 0; i < cfg->num_varinfo; i++) {
1124 MonoMethodVar *info = MONO_VARINFO (cfg, i);
1131 while (bblock_list) {
1134 bb = (MonoBasicBlock *)bblock_list->data;
1136 bblock_list = g_list_delete_link (bblock_list, bblock_list);
1138 g_assert (bb->flags & BB_REACHABLE);
1140 if (bb->out_count == 1) {
1141 if (!(bb->out_bb [0]->flags & BB_REACHABLE)) {
1142 bb->out_bb [0]->flags |= BB_REACHABLE;
1143 bblock_list = g_list_prepend (bblock_list, bb->out_bb [0]);
1147 MONO_BB_FOR_EACH_INS (bb, inst)
1148 visit_inst (cfg, bb, inst, &cvars, &bblock_list, carray);
1151 MonoMethodVar *info = (MonoMethodVar *)cvars->data;
1152 cvars = g_list_delete_link (cvars, cvars);
1154 for (tmp = info->uses; tmp; tmp = tmp->next) {
1155 MonoVarUsageInfo *ui = (MonoVarUsageInfo *)tmp->data;
1156 if (!(ui->bb->flags & BB_REACHABLE))
1158 visit_inst (cfg, ui->bb, ui->inst, &cvars, &bblock_list, carray);
1163 for (bb = cfg->bb_entry->next_bb; bb; bb = bb->next_bb) {
1165 MONO_BB_FOR_EACH_INS (bb, inst)
1166 fold_tree (cfg, bb, inst, carray);
1171 cfg->comp_done |= MONO_COMP_REACHABILITY;
1175 add_to_dce_worklist (MonoCompile *cfg, MonoMethodVar *var, MonoMethodVar *use, GList **wl)
1179 *wl = g_list_prepend (*wl, use);
1181 for (tmp = use->uses; tmp; tmp = tmp->next) {
1182 MonoVarUsageInfo *ui = (MonoVarUsageInfo *)tmp->data;
1183 if (ui->inst == var->def) {
1184 /* from the mempool */
1185 use->uses = g_list_remove_link (use->uses, tmp);
1192 mono_ssa_deadce (MonoCompile *cfg)
1197 g_assert (cfg->comp_done & MONO_COMP_SSA);
1199 //printf ("DEADCE %s\n", mono_method_full_name (cfg->method, TRUE));
1201 /* fixme: we should update usage infos during cprop, instead of computing it again */
1202 cfg->comp_done &= ~MONO_COMP_SSA_DEF_USE;
1203 for (i = 0; i < cfg->num_varinfo; i++) {
1204 MonoMethodVar *info = MONO_VARINFO (cfg, i);
1209 if (!(cfg->comp_done & MONO_COMP_SSA_DEF_USE))
1210 mono_ssa_create_def_use (cfg);
1212 mono_ssa_avoid_copies (cfg);
1215 for (i = 0; i < cfg->num_varinfo; i++) {
1216 MonoMethodVar *info = MONO_VARINFO (cfg, i);
1217 work_list = g_list_prepend (work_list, info);
1219 //if ((info->def != NULL) && (info->def->inst_i1->opcode != OP_PHI)) printf ("SSA DEADCE TOTAL LOCAL\n");
1223 MonoMethodVar *info = (MonoMethodVar *)work_list->data;
1224 work_list = g_list_delete_link (work_list, work_list);
1226 if (!info->uses && info->def && (!(cfg->varinfo [info->idx]->flags & (MONO_INST_DEFINITION_HAS_SIDE_EFFECTS|MONO_INST_VOLATILE|MONO_INST_INDIRECT)))) {
1228 //printf ("ELIMINATE %s: ", mono_method_full_name (cfg->method, TRUE)); mono_print_tree (info->def); printf ("\n");
1230 i1 = info->def->inst_i1;
1231 if (i1->opcode == OP_PHI) {
1233 for (j = i1->inst_phi_args [0]; j > 0; j--) {
1234 MonoMethodVar *u = MONO_VARINFO (cfg, i1->inst_phi_args [j]);
1235 add_to_dce_worklist (cfg, info, u, &work_list);
1237 } else if (i1->ssa_op == MONO_SSA_LOAD &&
1238 (i1->inst_i0->opcode == OP_LOCAL || i1->inst_i0->opcode == OP_ARG)) {
1239 MonoMethodVar *u = MONO_VARINFO (cfg, i1->inst_i0->inst_c0);
1240 add_to_dce_worklist (cfg, info, u, &work_list);
1242 //if (i1->opcode != OP_PHI) printf ("SSA DEADCE DEAD LOCAL\n");
1244 info->def->opcode = OP_NOP;
1245 info->def->ssa_op = MONO_SSA_NOP;
1253 mono_ssa_strength_reduction (MonoCompile *cfg)
1258 g_assert (cfg->comp_done & MONO_COMP_SSA);
1259 g_assert (cfg->comp_done & MONO_COMP_LOOPS);
1260 g_assert (cfg->comp_done & MONO_COMP_SSA_DEF_USE);
1262 for (bb = cfg->bb_entry->next_bb; bb; bb = bb->next_bb) {
1263 GList *lp = bb->loop_blocks;
1266 MonoBasicBlock *h = (MonoBasicBlock *)lp->data;
1268 /* we only consider loops with 2 in bblocks */
1269 if (!h->in_count == 2)
1272 for (i = 0; i < cfg->num_varinfo; i++) {
1273 MonoMethodVar *info = MONO_VARINFO (cfg, i);
1275 if (info->def && info->def->ssa_op == MONO_SSA_STORE &&
1276 info->def->inst_i0->opcode == OP_LOCAL && g_list_find (lp, info->def_bb)) {
1277 MonoInst *v = info->def->inst_i1;
1280 printf ("FOUND %d in %s\n", info->idx, mono_method_full_name (cfg->method, TRUE));
1288 #endif /* DISABLE_SSA */