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);
140 extends_live (MonoInst *inst)
147 arity = mono_burg_arity [inst->opcode];
149 if (inst->ssa_op == MONO_SSA_LOAD &&
150 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG)) {
154 if (inst->ssa_op != MONO_SSA_STORE)
155 if (extends_live (inst->inst_left))
158 if (extends_live (inst->inst_right))
167 replace_usage_new (MonoCompile *cfg, MonoInst *inst, int varnum, MonoInst *rep)
174 arity = mono_burg_arity [inst->opcode];
176 if ((inst->ssa_op == MONO_SSA_LOAD) &&
177 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG) &&
178 inst->inst_i0->inst_c0 == varnum && rep->type == inst->type) {
183 if (inst->ssa_op != MONO_SSA_STORE)
184 if (replace_usage_new (cfg, inst->inst_left, varnum, rep))
187 if (replace_usage_new (cfg, inst->inst_right, varnum, rep))
196 mono_ssa_rename_vars (MonoCompile *cfg, int max_vars, MonoBasicBlock *bb, MonoInst **stack)
198 MonoInst *inst, *new_var;
201 MonoInst **new_stack;
204 printf ("RENAME VARS BB%d %s\n", bb->block_num, mono_method_full_name (cfg->method, TRUE));
207 MONO_BB_FOR_EACH_INS (bb, inst) {
208 if (inst->opcode != OP_PHI)
209 replace_usage (cfg, bb, inst, stack);
211 if (inst->ssa_op == MONO_SSA_STORE &&
212 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG)) {
213 idx = inst->inst_i0->inst_c0;
214 g_assert (idx < max_vars);
216 if ((!stack [idx]) && (bb == cfg->bb_init) && (inst->inst_i0->opcode != OP_ARG)) {
217 new_var = cfg->varinfo [idx];
219 new_var = mono_compile_create_var (cfg, inst->inst_i0->inst_vtype, inst->inst_i0->opcode);
220 new_var->flags = inst->inst_i0->flags;
223 printf ("DEF %d %d\n", idx, new_var->inst_c0);
225 inst->inst_i0 = new_var;
227 #ifdef USE_ORIGINAL_VARS
228 MONO_VARINFO (cfg, new_var->inst_c0)->reg = idx;
231 stack [idx] = new_var;
235 for (i = 0; i < bb->out_count; i++) {
236 MonoBasicBlock *n = bb->out_bb [i];
238 for (j = 0; j < n->in_count; j++)
239 if (n->in_bb [j] == bb)
242 MONO_BB_FOR_EACH_INS (n, inst) {
243 if (inst->ssa_op == MONO_SSA_STORE && inst->inst_i1->opcode == OP_PHI) {
244 idx = inst->inst_i1->inst_c0;
246 new_var = stack [idx];
248 new_var = cfg->varinfo [idx];
250 printf ("FOUND PHI %d (%d, %d)\n", idx, j, new_var->inst_c0);
252 inst->inst_i1->inst_phi_args [j + 1] = new_var->inst_c0;
259 new_stack = g_new (MonoInst*, max_vars);
260 for (tmp = bb->dominated; tmp; tmp = tmp->next) {
261 memcpy (new_stack, stack, sizeof (MonoInst *) * max_vars);
262 mono_ssa_rename_vars (cfg, max_vars, (MonoBasicBlock *)tmp->data, new_stack);
269 mono_ssa_compute (MonoCompile *cfg)
273 MonoMethodVar *vinfo = g_new0 (MonoMethodVar, cfg->num_varinfo);
274 MonoInst *inst, *store, **stack;
276 g_assert (!(cfg->comp_done & MONO_COMP_SSA));
278 /* we dont support methods containing exception clauses */
279 g_assert (mono_method_get_header (cfg->method)->num_clauses == 0);
280 g_assert (!cfg->disable_ssa);
282 //printf ("COMPUTS SSA %s %d\n", mono_method_full_name (cfg->method, TRUE), cfg->num_varinfo);
284 #ifdef CREATE_PRUNED_SSA
285 /* we need liveness for pruned SSA */
286 if (!(cfg->comp_done & MONO_COMP_LIVENESS))
287 mono_analyze_liveness (cfg);
290 mono_compile_dominator_info (cfg, MONO_COMP_DOM | MONO_COMP_IDOM | MONO_COMP_DFRONTIER);
292 for (i = 0; i < cfg->num_varinfo; ++i) {
293 vinfo [i].def_in = mono_bitset_new (cfg->num_bblocks, 0);
295 /* implizit reference at start */
296 mono_bitset_set (vinfo [i].def_in, 0);
298 for (i = 0; i < cfg->num_bblocks; ++i) {
299 MONO_BB_FOR_EACH_INS (cfg->bblocks [i], inst) {
300 if (inst->ssa_op == MONO_SSA_STORE) {
301 idx = inst->inst_i0->inst_c0;
302 g_assert (idx < cfg->num_varinfo);
303 mono_bitset_set (vinfo [idx].def_in, i);
308 /* insert phi functions */
309 for (i = 0; i < cfg->num_varinfo; ++i) {
310 set = mono_compile_iterated_dfrontier (cfg, vinfo [i].def_in);
311 vinfo [i].dfrontier = set;
312 mono_bitset_foreach_bit (set, idx, cfg->num_bblocks) {
313 MonoBasicBlock *bb = cfg->bblocks [idx];
315 /* fixme: create pruned SSA? we would need liveness information for that */
317 if (bb == cfg->bb_exit)
320 if ((cfg->comp_done & MONO_COMP_LIVENESS) && !mono_bitset_test_fast (bb->live_in_set, i)) {
321 //printf ("%d is not live in BB%d %s\n", i, bb->block_num, mono_method_full_name (cfg->method, TRUE));
325 NEW_PHI (cfg, inst, i);
327 inst->inst_phi_args = mono_mempool_alloc0 (cfg->mempool, sizeof (int) * (cfg->bblocks [idx]->in_count + 1));
328 inst->inst_phi_args [0] = cfg->bblocks [idx]->in_count;
330 store = mono_mempool_alloc0 ((cfg)->mempool, sizeof (MonoInst));
331 if (!cfg->varinfo [i]->inst_vtype->type)
332 g_assert_not_reached ();
333 store->opcode = mono_type_to_stind (cfg->varinfo [i]->inst_vtype);
334 store->ssa_op = MONO_SSA_STORE;
335 store->inst_i0 = cfg->varinfo [i];
336 store->inst_i1 = inst;
337 store->klass = store->inst_i0->klass;
339 MONO_INST_LIST_ADD (&store->node, &bb->ins_list);
342 printf ("ADD PHI BB%d %s\n", cfg->bblocks [idx]->block_num, mono_method_full_name (cfg->method, TRUE));
348 for (i = 0; i < cfg->num_varinfo; ++i)
349 mono_bitset_free (vinfo [i].def_in);
353 stack = alloca (sizeof (MonoInst *) * cfg->num_varinfo);
355 for (i = 0; i < cfg->num_varinfo; i++)
358 mono_ssa_rename_vars (cfg, cfg->num_varinfo, cfg->bb_entry, stack);
360 cfg->comp_done |= MONO_COMP_SSA;
363 #ifndef USE_ORIGINAL_VARS
365 mono_ssa_get_allocatable_vars (MonoCompile *cfg)
367 GHashTable *type_hash;
368 GPtrArray *varlist_array = g_ptr_array_new ();
371 g_assert (cfg->comp_done & MONO_COMP_LIVENESS);
373 type_hash = g_hash_table_new (NULL, NULL);
375 for (i = 0; i < cfg->num_varinfo; i++) {
376 MonoInst *ins = cfg->varinfo [i];
377 MonoMethodVar *vmv = MONO_VARINFO (cfg, i);
380 if (vmv->range.first_use.abs_pos > vmv->range.last_use.abs_pos)
383 if (ins->flags & (MONO_INST_VOLATILE|MONO_INST_INDIRECT) ||
384 (ins->opcode != OP_LOCAL && ins->opcode != OP_ARG) || vmv->reg != -1)
387 g_assert (ins->inst_vtype);
388 g_assert (vmv->reg == -1);
389 g_assert (i == vmv->idx);
391 if (!(tidx = (int)g_hash_table_lookup (type_hash, ins->inst_vtype))) {
392 GList *vars = g_list_append (NULL, vmv);
393 g_ptr_array_add (varlist_array, vars);
394 g_hash_table_insert (type_hash, ins->inst_vtype, (gpointer)varlist_array->len);
397 g_ptr_array_index (varlist_array, tidx) =
398 mono_varlist_insert_sorted (cfg, g_ptr_array_index (varlist_array, tidx), vmv, FALSE);
402 g_hash_table_destroy (type_hash);
404 return varlist_array;
409 mono_ssa_replace_copies (MonoCompile *cfg, MonoBasicBlock *bb, MonoInst *inst, char *is_live)
416 arity = mono_burg_arity [inst->opcode];
418 if ((inst->ssa_op == MONO_SSA_LOAD || inst->ssa_op == MONO_SSA_ADDRESS_TAKEN || inst->ssa_op == MONO_SSA_STORE) &&
419 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG)) {
421 int idx = inst->inst_i0->inst_c0;
422 MonoMethodVar *mv = MONO_VARINFO (cfg, idx);
424 if (mv->reg != -1 && mv->reg != mv->idx) {
426 is_live [mv->reg] = 1;
428 new_var = cfg->varinfo [mv->reg];
431 printf ("REPLACE COPY BB%d %d %d\n", bb->block_num, idx, new_var->inst_c0);
432 g_assert (cfg->varinfo [mv->reg]->inst_vtype == cfg->varinfo [idx]->inst_vtype);
434 inst->inst_i0 = new_var;
436 is_live [mv->idx] = 1;
442 mono_ssa_replace_copies (cfg, bb, inst->inst_left, is_live);
444 mono_ssa_replace_copies (cfg, bb, inst->inst_right, is_live);
447 if (inst->ssa_op == MONO_SSA_STORE && inst->inst_i1->ssa_op == MONO_SSA_LOAD &&
448 inst->inst_i0->inst_c0 == inst->inst_i1->inst_i0->inst_c0) {
449 inst->ssa_op = MONO_SSA_NOP;
450 inst->opcode = OP_NOP;
456 mono_ssa_remove (MonoCompile *cfg)
458 MonoInst *inst, *phi;
461 #ifndef USE_ORIGINAL_VARS
462 GPtrArray *varlist_array;
465 g_assert (cfg->comp_done & MONO_COMP_SSA);
467 for (i = 0; i < cfg->num_bblocks; ++i) {
468 MonoBasicBlock *bb = cfg->bblocks [i];
469 MONO_BB_FOR_EACH_INS (bb, inst) {
470 if (inst->ssa_op == MONO_SSA_STORE && inst->inst_i1->opcode == OP_PHI) {
473 g_assert (phi->inst_phi_args [0] == bb->in_count);
475 for (j = 0; j < bb->in_count; j++) {
476 MonoBasicBlock *pred = bb->in_bb [j];
477 int idx = phi->inst_phi_args [j + 1];
478 MonoMethodVar *mv = MONO_VARINFO (cfg, idx);
480 if (mv->reg != -1 && mv->reg != mv->idx) {
481 //printf ("PHICOPY %d %d -> %d\n", idx, mv->reg, inst->inst_i0->inst_c0);
486 if (idx != inst->inst_i0->inst_c0) {
488 printf ("MOVE %d to %d in BB%d\n", idx, inst->inst_i0->inst_c0, pred->block_num);
490 mono_add_varcopy_to_end (cfg, pred, idx, inst->inst_i0->inst_c0);
494 /* remove the phi functions */
495 inst->opcode = OP_NOP;
496 inst->ssa_op = MONO_SSA_NOP;
501 #ifndef USE_ORIGINAL_VARS
502 /* we compute liveness again */
503 cfg->comp_done &= ~MONO_COMP_LIVENESS;
504 mono_analyze_liveness (cfg);
506 varlist_array = mono_ssa_get_allocatable_vars (cfg);
508 for (i = 0; i < varlist_array->len; i++) {
509 GList *l, *regs, *vars = g_ptr_array_index (varlist_array, i);
510 MonoMethodVar *vmv, *amv;
512 if (g_list_length (vars) <= 1) {
519 for (l = vars; l; l = l->next) {
522 /* expire old intervals in active */
524 amv = (MonoMethodVar *)active->data;
526 if (amv->range.last_use.abs_pos >= vmv->range.first_use.abs_pos)
529 active = g_list_delete_link (active, active);
530 regs = g_list_prepend (regs, (gpointer)amv->reg);
534 regs = g_list_prepend (regs, (gpointer)vmv->idx);
536 vmv->reg = (int)regs->data;
537 regs = g_list_delete_link (regs, regs);
538 active = mono_varlist_insert_sorted (cfg, active, vmv, TRUE);
541 g_list_free (active);
546 g_ptr_array_free (varlist_array, TRUE);
550 is_live = alloca (cfg->num_varinfo);
551 memset (is_live, 0, cfg->num_varinfo);
553 for (i = 0; i < cfg->num_bblocks; ++i) {
554 MonoBasicBlock *bb = cfg->bblocks [i];
556 MONO_BB_FOR_EACH_INS (bb, inst)
557 mono_ssa_replace_copies (cfg, bb, inst, is_live);
560 for (i = 0; i < cfg->num_varinfo; ++i) {
561 MONO_VARINFO (cfg, i)->reg = -1;
562 if (!is_live [i] && !(cfg->varinfo [i]->flags & MONO_INST_VOLATILE)) {
563 cfg->varinfo [i]->flags |= MONO_INST_IS_DEAD;
567 if (cfg->comp_done & MONO_COMP_REACHABILITY)
568 unlink_unused_bblocks (cfg);
570 cfg->comp_done &= ~MONO_COMP_SSA;
574 #define IS_CALL(op) (op == CEE_CALLI || op == OP_CALL || op == OP_CALLVIRT || (op >= OP_VOIDCALL && op <= OP_CALL_MEMBASE))
585 * Returns TRUE if the tree can have side effects.
588 analyze_dev_use (MonoCompile *cfg, MonoBasicBlock *bb, MonoInst *root, MonoInst *inst)
592 gboolean has_side_effects;
597 arity = mono_burg_arity [inst->opcode];
598 switch (inst->opcode) {
599 #define ANALYZE_DEV_USE_SPECIFIC_OPS 1
600 #define OPDEF(a1,a2,a3,a4,a5,a6,a7,a8,a9,a10) case a1:
601 #include "simple-cee-ops.h"
603 #define MINI_OP(a1,a2) case a1:
604 #include "simple-mini-ops.h"
606 #undef ANALYZE_DEV_USE_SPECIFIC_OPS
607 has_side_effects = FALSE;
610 has_side_effects = TRUE;
613 if ((inst->ssa_op == MONO_SSA_STORE) &&
614 (inst->inst_i0->opcode == OP_LOCAL /*|| inst->inst_i0->opcode == OP_ARG */)) {
615 idx = inst->inst_i0->inst_c0;
616 info = MONO_VARINFO (cfg, idx);
617 //printf ("%d defined in BB%d %p\n", idx, bb->block_num, root);
619 g_warning ("more than one definition of variable %d in %s", idx,
620 mono_method_full_name (cfg->method, TRUE));
621 g_assert_not_reached ();
623 if (!IS_CALL (inst->inst_i1->opcode) /* && inst->inst_i1->opcode == OP_ICONST */) {
624 g_assert (inst == root);
629 if (inst->inst_i1->opcode == OP_PHI) {
630 for (i = inst->inst_i1->inst_phi_args [0]; i > 0; i--) {
631 MonoVarUsageInfo *ui = mono_mempool_alloc (cfg->mempool, sizeof (MonoVarUsageInfo));
632 idx = inst->inst_i1->inst_phi_args [i];
633 info = MONO_VARINFO (cfg, idx);
634 //printf ("FOUND %d\n", idx);
637 info->uses = g_list_prepend_mempool (info->uses, cfg->mempool, ui);
642 if ((inst->ssa_op == MONO_SSA_LOAD || inst->ssa_op == MONO_SSA_ADDRESS_TAKEN) &&
643 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG)) {
644 MonoVarUsageInfo *ui = mono_mempool_alloc (cfg->mempool, sizeof (MonoVarUsageInfo));
645 idx = inst->inst_i0->inst_c0;
646 info = MONO_VARINFO (cfg, idx);
647 //printf ("FOUND %d\n", idx);
650 info->uses = g_list_prepend_mempool (info->uses, cfg->mempool, ui);
653 //if (inst->ssa_op != MONO_SSA_STORE)
654 if (analyze_dev_use (cfg, bb, root, inst->inst_left))
655 has_side_effects = TRUE;
657 if (analyze_dev_use (cfg, bb, root, inst->inst_right))
658 has_side_effects = TRUE;
662 return has_side_effects;
666 /* avoid unnecessary copies of variables:
667 * Y <= X; Z = Y; is translated to Z = X;
670 mono_ssa_avoid_copies (MonoCompile *cfg)
672 MonoInst *inst, *next;
674 MonoMethodVar *i1, *i2;
676 g_assert ((cfg->comp_done & MONO_COMP_SSA_DEF_USE));
678 for (bb = cfg->bb_entry; bb; bb = bb->next_bb) {
679 MONO_BB_FOR_EACH_INS (bb, inst) {
680 if (inst->ssa_op == MONO_SSA_STORE && inst->inst_i0->opcode == OP_LOCAL &&
681 !IS_CALL (inst->inst_i1->opcode) && inst->inst_i1->opcode != OP_PHI && !inst->flags) {
682 i1 = MONO_VARINFO (cfg, inst->inst_i0->inst_c0);
684 /* fixme: compiling mcs does not work when I enable this */
686 if (g_list_length (i1->uses) == 1 && !extends_live (inst->inst_i1)) {
687 MonoVarUsageInfo *vi = (MonoVarUsageInfo *)i1->uses->data;
690 //printf ("VAR %d %s\n", i1->idx, mono_method_full_name (cfg->method, TRUE));
691 //mono_print_tree (inst); printf ("\n");
692 //mono_print_tree (u); printf ("\n");
694 if (replace_usage_new (cfg, u, inst->inst_i0->inst_c0, inst->inst_i1)) {
696 //mono_print_tree (u); printf ("\n");
698 inst->opcode = OP_NOP;
699 inst->ssa_op = MONO_SSA_NOP;
703 next = mono_inst_list_next (&inst->node, &bb->ins_list);
704 if (next && next->ssa_op == MONO_SSA_STORE &&
705 next->inst_i0->opcode == OP_LOCAL &&
706 next->inst_i1->ssa_op == MONO_SSA_LOAD &&
707 next->inst_i1->inst_i0->opcode == OP_LOCAL &&
708 next->inst_i1->inst_i0->inst_c0 == inst->inst_i0->inst_c0 &&
709 g_list_length (i1->uses) == 1 &&
710 inst->opcode == next->opcode &&
711 inst->inst_i0->type == next->inst_i0->type) {
712 i2 = MONO_VARINFO (cfg, next->inst_i0->inst_c0);
713 //printf ("ELIM. COPY in BB%d %s\n", bb->block_num, mono_method_full_name (cfg->method, TRUE));
714 inst->inst_i0 = next->inst_i0;
718 next->opcode = OP_NOP;
719 next->ssa_op = MONO_SSA_NOP;
727 mono_ssa_create_def_use (MonoCompile *cfg)
731 g_assert (!(cfg->comp_done & MONO_COMP_SSA_DEF_USE));
733 for (bb = cfg->bb_entry; bb; bb = bb->next_bb) {
735 MONO_BB_FOR_EACH_INS (bb, inst) {
736 gboolean has_side_effects = analyze_dev_use (cfg, bb, inst, inst);
737 if (has_side_effects && (inst->ssa_op == MONO_SSA_STORE) &&
738 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG)) {
739 inst->inst_i0->flags |= MONO_INST_DEFINITION_HAS_SIDE_EFFECTS;
744 cfg->comp_done |= MONO_COMP_SSA_DEF_USE;
748 simulate_compare (int opcode, int a, int b)
764 return (unsigned)a >= (unsigned)b;
766 return (unsigned)a > (unsigned)b;
768 return (unsigned)a <= (unsigned)b;
770 return (unsigned)a < (unsigned)b;
772 g_assert_not_reached ();
779 simulate_long_compare (int opcode, gint64 a, gint64 b)
795 return (guint64)a >= (guint64)b;
797 return (guint64)a > (guint64)b;
799 return (guint64)a <= (guint64)b;
801 return (guint64)a < (guint64)b;
803 g_assert_not_reached ();
809 #define EVAL_CXX(name,op,cast) \
811 if ((inst->inst_i0->opcode == OP_COMPARE) || (inst->inst_i0->opcode == OP_LCOMPARE)) { \
812 r1 = evaluate_const_tree (cfg, inst->inst_i0->inst_i0, &a, carray); \
813 r2 = evaluate_const_tree (cfg, inst->inst_i0->inst_i1, &b, carray); \
814 if (r1 == 1 && r2 == 1) { \
815 *res = ((cast)a op (cast)b); \
818 return MAX (r1, r2); \
823 #define EVAL_BINOP(name,op) \
825 r1 = evaluate_const_tree (cfg, inst->inst_i0, &a, carray); \
826 r2 = evaluate_const_tree (cfg, inst->inst_i1, &b, carray); \
827 if (r1 == 1 && r2 == 1) { \
831 return MAX (r1, r2); \
836 /* fixme: this only works for interger constants, but not for other types (long, float) */
838 evaluate_const_tree (MonoCompile *cfg, MonoInst *inst, int *res, MonoInst **carray)
846 if (inst->ssa_op == MONO_SSA_LOAD &&
847 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG) &&
848 (c0 = carray [inst->inst_i0->inst_c0])) {
853 switch (inst->opcode) {
855 *res = inst->inst_c0;
858 EVAL_CXX (OP_CEQ,==,gint32)
859 EVAL_CXX (OP_CGT,>,gint32)
860 EVAL_CXX (OP_CGT_UN,>,guint32)
861 EVAL_CXX (OP_CLT,<,gint32)
862 EVAL_CXX (OP_CLT_UN,<,guint32)
864 EVAL_BINOP (CEE_ADD,+)
865 EVAL_BINOP (CEE_SUB,-)
866 EVAL_BINOP (CEE_MUL,*)
867 EVAL_BINOP (CEE_AND,&)
868 EVAL_BINOP (CEE_OR,|)
869 EVAL_BINOP (CEE_XOR,^)
870 EVAL_BINOP (CEE_SHL,<<)
871 EVAL_BINOP (CEE_SHR,>>)
881 fold_tree (MonoCompile *cfg, MonoBasicBlock *bb, MonoInst *inst, MonoInst **carray)
889 arity = mono_burg_arity [inst->opcode];
891 if (inst->ssa_op == MONO_SSA_STORE &&
892 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG) &&
893 inst->inst_i1->opcode == OP_PHI && (c0 = carray [inst->inst_i0->inst_c0])) {
894 //{static int cn = 0; printf ("PHICONST %d %d %s\n", cn++, c0->inst_c0, mono_method_full_name (cfg->method, TRUE));}
895 *inst->inst_i1 = *c0;
896 } else if (inst->ssa_op == MONO_SSA_LOAD &&
897 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG) &&
898 (c0 = carray [inst->inst_i0->inst_c0])) {
899 //{static int cn = 0; printf ("YCCOPY %d %d %s\n", cn++, c0->inst_c0, mono_method_full_name (cfg->method, TRUE));}
904 fold_tree (cfg, bb, inst->inst_left, carray);
906 fold_tree (cfg, bb, inst->inst_right, carray);
907 mono_constant_fold_inst (inst, NULL);
911 if ((inst->opcode >= CEE_BEQ && inst->opcode <= CEE_BLT_UN) &&
912 ((inst->inst_i0->opcode == OP_COMPARE) || (inst->inst_i0->opcode == OP_LCOMPARE))) {
913 MonoInst *v0 = inst->inst_i0->inst_i0;
914 MonoInst *v1 = inst->inst_i0->inst_i1;
915 MonoBasicBlock *target = NULL;
917 /* hack for longs to optimize the simply cases */
918 if (v0->opcode == OP_I8CONST && v1->opcode == OP_I8CONST) {
919 if (simulate_long_compare (inst->opcode, v0->inst_l, v1->inst_l)) {
920 //unlink_target (bb, inst->inst_false_bb);
921 target = inst->inst_true_bb;
923 //unlink_target (bb, inst->inst_true_bb);
924 target = inst->inst_false_bb;
926 } else if (evaluate_const_tree (cfg, v0, &a, carray) == 1 &&
927 evaluate_const_tree (cfg, v1, &b, carray) == 1) {
928 if (simulate_compare (inst->opcode, a, b)) {
929 //unlink_target (bb, inst->inst_false_bb);
930 target = inst->inst_true_bb;
932 //unlink_target (bb, inst->inst_true_bb);
933 target = inst->inst_false_bb;
938 bb->out_bb [0] = target;
940 inst->opcode = OP_BR;
941 inst->inst_target_bb = target;
943 } else if (inst->opcode == OP_SWITCH && (evaluate_const_tree (cfg, inst->inst_left, &a, carray) == 1) && (a >= 0) && (a < GPOINTER_TO_INT (inst->klass))) {
944 bb->out_bb [0] = inst->inst_many_bb [a];
946 inst->inst_target_bb = bb->out_bb [0];
947 inst->opcode = OP_BR;
953 change_varstate (MonoCompile *cfg, GList **cvars, MonoMethodVar *info, int state, MonoInst *c0, MonoInst **carray)
955 if (info->cpstate >= state)
958 info->cpstate = state;
960 //printf ("SETSTATE %d to %d\n", info->idx, info->cpstate);
963 carray [info->idx] = c0;
965 carray [info->idx] = NULL;
967 if (!g_list_find (*cvars, info)) {
968 *cvars = g_list_prepend (*cvars, info);
973 visit_inst (MonoCompile *cfg, MonoBasicBlock *bb, MonoInst *inst, GList **cvars, GList **bblist, MonoInst **carray)
977 if (inst->opcode == OP_SWITCH) {
979 int cases = GPOINTER_TO_INT (inst->klass);
981 r1 = evaluate_const_tree (cfg, inst->inst_left, &a, carray);
982 if ((r1 == 1) && ((a < 0) || (a >= cases)))
985 MonoBasicBlock *tb = inst->inst_many_bb [a];
986 if (!(tb->flags & BB_REACHABLE)) {
987 tb->flags |= BB_REACHABLE;
988 *bblist = g_list_prepend (*bblist, tb);
990 } else if (r1 == 2) {
991 for (i = GPOINTER_TO_INT (inst->klass); i >= 0; i--) {
992 MonoBasicBlock *tb = inst->inst_many_bb [i];
993 if (!(tb->flags & BB_REACHABLE)) {
994 tb->flags |= BB_REACHABLE;
995 *bblist = g_list_prepend (*bblist, tb);
999 } else if (inst->opcode == OP_BR) {
1000 MonoBasicBlock *target = inst->inst_target_bb;
1002 if (!(target->flags & BB_REACHABLE)) {
1003 target->flags |= BB_REACHABLE;
1004 *bblist = g_list_prepend (*bblist, target);
1006 } else if ((inst->opcode >= CEE_BEQ && inst->opcode <= CEE_BLT_UN) &&
1007 ((inst->inst_i0->opcode == OP_COMPARE) || (inst->inst_i0->opcode == OP_LCOMPARE))) {
1009 MonoInst *v0 = inst->inst_i0->inst_i0;
1010 MonoInst *v1 = inst->inst_i0->inst_i1;
1012 r1 = evaluate_const_tree (cfg, v0, &a, carray);
1013 r2 = evaluate_const_tree (cfg, v1, &b, carray);
1015 if (r1 == 1 && r2 == 1) {
1016 MonoBasicBlock *target;
1018 if (simulate_compare (inst->opcode, a, b)) {
1019 target = inst->inst_true_bb;
1021 target = inst->inst_false_bb;
1023 if (!(target->flags & BB_REACHABLE)) {
1024 target->flags |= BB_REACHABLE;
1025 *bblist = g_list_prepend (*bblist, target);
1027 } else if (r1 == 2 || r2 == 2) {
1028 if (!(inst->inst_true_bb->flags & BB_REACHABLE)) {
1029 inst->inst_true_bb->flags |= BB_REACHABLE;
1030 *bblist = g_list_prepend (*bblist, inst->inst_true_bb);
1032 if (!(inst->inst_false_bb->flags & BB_REACHABLE)) {
1033 inst->inst_false_bb->flags |= BB_REACHABLE;
1034 *bblist = g_list_prepend (*bblist, inst->inst_false_bb);
1037 } else if (inst->ssa_op == MONO_SSA_STORE &&
1038 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG)) {
1039 MonoMethodVar *info = MONO_VARINFO (cfg, inst->inst_i0->inst_c0);
1040 MonoInst *i1 = inst->inst_i1;
1043 if (info->cpstate < 2) {
1044 if (i1->opcode == OP_ICONST) {
1045 change_varstate (cfg, cvars, info, 1, i1, carray);
1046 } else if (i1->opcode == OP_PHI) {
1047 MonoInst *c0 = NULL;
1050 for (j = 1; j <= i1->inst_phi_args [0]; j++) {
1051 MonoMethodVar *mv = MONO_VARINFO (cfg, i1->inst_phi_args [j]);
1052 MonoInst *src = mv->def;
1054 if (mv->def_bb && !(mv->def_bb->flags & BB_REACHABLE)) {
1058 if (!mv->def || !src || src->ssa_op != MONO_SSA_STORE ||
1059 !(src->inst_i0->opcode == OP_LOCAL || src->inst_i0->opcode == OP_ARG) ||
1061 change_varstate (cfg, cvars, info, 2, NULL, carray);
1065 if (mv->cpstate == 0)
1068 //g_assert (src->inst_i1->opcode == OP_ICONST);
1069 g_assert (carray [mv->idx]);
1072 c0 = carray [mv->idx];
1075 if (carray [mv->idx]->inst_c0 != c0->inst_c0) {
1076 change_varstate (cfg, cvars, info, 2, NULL, carray);
1081 if (c0 && info->cpstate < 1) {
1082 change_varstate (cfg, cvars, info, 1, c0, carray);
1085 int state = evaluate_const_tree (cfg, i1, &res, carray);
1087 NEW_ICONST (cfg, i1, res);
1088 change_varstate (cfg, cvars, info, 1, i1, carray);
1090 change_varstate (cfg, cvars, info, 2, NULL, carray);
1098 mono_ssa_cprop (MonoCompile *cfg)
1102 GList *bblock_list, *cvars;
1105 //printf ("SIMPLE OPTS BB%d %s\n", bb->block_num, mono_method_full_name (cfg->method, TRUE));
1107 carray = g_new0 (MonoInst*, cfg->num_varinfo);
1109 if (!(cfg->comp_done & MONO_COMP_SSA_DEF_USE))
1110 mono_ssa_create_def_use (cfg);
1112 bblock_list = g_list_prepend (NULL, cfg->bb_entry);
1113 cfg->bb_entry->flags |= BB_REACHABLE;
1115 memset (carray, 0, sizeof (MonoInst *) * cfg->num_varinfo);
1117 for (i = 0; i < cfg->num_varinfo; i++) {
1118 MonoMethodVar *info = MONO_VARINFO (cfg, i);
1125 while (bblock_list) {
1128 bb = (MonoBasicBlock *)bblock_list->data;
1130 bblock_list = g_list_delete_link (bblock_list, bblock_list);
1132 g_assert (bb->flags & BB_REACHABLE);
1134 if (bb->out_count == 1) {
1135 if (!(bb->out_bb [0]->flags & BB_REACHABLE)) {
1136 bb->out_bb [0]->flags |= BB_REACHABLE;
1137 bblock_list = g_list_prepend (bblock_list, bb->out_bb [0]);
1141 MONO_BB_FOR_EACH_INS (bb, inst)
1142 visit_inst (cfg, bb, inst, &cvars, &bblock_list, carray);
1145 MonoMethodVar *info = (MonoMethodVar *)cvars->data;
1146 cvars = g_list_delete_link (cvars, cvars);
1148 for (tmp = info->uses; tmp; tmp = tmp->next) {
1149 MonoVarUsageInfo *ui = (MonoVarUsageInfo *)tmp->data;
1150 if (!(ui->bb->flags & BB_REACHABLE))
1152 visit_inst (cfg, ui->bb, ui->inst, &cvars, &bblock_list, carray);
1157 for (bb = cfg->bb_entry->next_bb; bb; bb = bb->next_bb) {
1159 MONO_BB_FOR_EACH_INS (bb, inst)
1160 fold_tree (cfg, bb, inst, carray);
1165 cfg->comp_done |= MONO_COMP_REACHABILITY;
1169 add_to_dce_worklist (MonoCompile *cfg, MonoMethodVar *var, MonoMethodVar *use, GList **wl)
1173 *wl = g_list_prepend (*wl, use);
1175 for (tmp = use->uses; tmp; tmp = tmp->next) {
1176 MonoVarUsageInfo *ui = (MonoVarUsageInfo *)tmp->data;
1177 if (ui->inst == var->def) {
1178 /* from the mempool */
1179 use->uses = g_list_remove_link (use->uses, tmp);
1186 mono_ssa_deadce (MonoCompile *cfg)
1191 g_assert (cfg->comp_done & MONO_COMP_SSA);
1193 //printf ("DEADCE %s\n", mono_method_full_name (cfg->method, TRUE));
1195 /* fixme: we should update usage infos during cprop, instead of computing it again */
1196 cfg->comp_done &= ~MONO_COMP_SSA_DEF_USE;
1197 for (i = 0; i < cfg->num_varinfo; i++) {
1198 MonoMethodVar *info = MONO_VARINFO (cfg, i);
1203 if (!(cfg->comp_done & MONO_COMP_SSA_DEF_USE))
1204 mono_ssa_create_def_use (cfg);
1206 mono_ssa_avoid_copies (cfg);
1209 for (i = 0; i < cfg->num_varinfo; i++) {
1210 MonoMethodVar *info = MONO_VARINFO (cfg, i);
1211 work_list = g_list_prepend (work_list, info);
1213 //if ((info->def != NULL) && (info->def->inst_i1->opcode != OP_PHI)) printf ("SSA DEADCE TOTAL LOCAL\n");
1217 MonoMethodVar *info = (MonoMethodVar *)work_list->data;
1218 work_list = g_list_delete_link (work_list, work_list);
1220 if (!info->uses && info->def && (!(cfg->varinfo [info->idx]->flags & (MONO_INST_DEFINITION_HAS_SIDE_EFFECTS|MONO_INST_VOLATILE|MONO_INST_INDIRECT)))) {
1222 //printf ("ELIMINATE %s: ", mono_method_full_name (cfg->method, TRUE)); mono_print_tree (info->def); printf ("\n");
1224 i1 = info->def->inst_i1;
1225 if (i1->opcode == OP_PHI) {
1227 for (j = i1->inst_phi_args [0]; j > 0; j--) {
1228 MonoMethodVar *u = MONO_VARINFO (cfg, i1->inst_phi_args [j]);
1229 add_to_dce_worklist (cfg, info, u, &work_list);
1231 } else if (i1->ssa_op == MONO_SSA_LOAD &&
1232 (i1->inst_i0->opcode == OP_LOCAL || i1->inst_i0->opcode == OP_ARG)) {
1233 MonoMethodVar *u = MONO_VARINFO (cfg, i1->inst_i0->inst_c0);
1234 add_to_dce_worklist (cfg, info, u, &work_list);
1236 //if (i1->opcode != OP_PHI) printf ("SSA DEADCE DEAD LOCAL\n");
1238 info->def->opcode = OP_NOP;
1239 info->def->ssa_op = MONO_SSA_NOP;
1247 mono_ssa_strength_reduction (MonoCompile *cfg)
1252 g_assert (cfg->comp_done & MONO_COMP_SSA);
1253 g_assert (cfg->comp_done & MONO_COMP_LOOPS);
1254 g_assert (cfg->comp_done & MONO_COMP_SSA_DEF_USE);
1256 for (bb = cfg->bb_entry->next_bb; bb; bb = bb->next_bb) {
1257 GList *lp = bb->loop_blocks;
1260 MonoBasicBlock *h = (MonoBasicBlock *)lp->data;
1262 /* we only consider loops with 2 in bblocks */
1263 if (!h->in_count == 2)
1266 for (i = 0; i < cfg->num_varinfo; i++) {
1267 MonoMethodVar *info = MONO_VARINFO (cfg, i);
1269 if (info->def && info->def->ssa_op == MONO_SSA_STORE &&
1270 info->def->inst_i0->opcode == OP_LOCAL && g_list_find (lp, info->def_bb)) {
1271 MonoInst *v = info->def->inst_i1;
1274 printf ("FOUND %d in %s\n", info->idx, mono_method_full_name (cfg->method, TRUE));
1282 #endif /* DISABLE_SSA */