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 #define USE_ORIGINAL_VARS
15 #define CREATE_PRUNED_SSA
19 #define NEW_PHI(cfg,dest,val) do { \
20 (dest) = mono_mempool_alloc0 ((cfg)->mempool, sizeof (MonoInst)); \
21 (dest)->opcode = OP_PHI; \
22 (dest)->inst_c0 = (val); \
25 #define NEW_ICONST(cfg,dest,val) do { \
26 (dest) = mono_mempool_alloc0 ((cfg)->mempool, sizeof (MonoInst)); \
27 (dest)->opcode = OP_ICONST; \
28 (dest)->inst_c0 = (val); \
29 (dest)->type = STACK_I4; \
34 g_list_prepend_mempool (GList* l, MonoMemPool* mp, gpointer datum)
36 GList* n = mono_mempool_alloc (mp, sizeof (GList));
44 unlink_target (MonoBasicBlock *bb, MonoBasicBlock *target)
48 for (i = 0; i < bb->out_count; i++) {
49 if (bb->out_bb [i] == target) {
50 bb->out_bb [i] = bb->out_bb [--bb->out_count];
54 for (i = 0; i < target->in_count; i++) {
55 if (target->in_bb [i] == bb) {
56 target->in_bb [i] = target->in_bb [--target->in_count];
64 unlink_unused_bblocks (MonoCompile *cfg)
69 g_assert (cfg->comp_done & MONO_COMP_REACHABILITY);
71 for (bb = cfg->bb_entry; bb && bb->next_bb;) {
72 if (!(bb->next_bb->flags & BB_REACHABLE)) {
73 bb->next_bb = bb->next_bb->next_bb;
78 for (i = 1; i < cfg->num_bblocks; i++) {
79 bb = cfg->bblocks [i];
81 if (!(bb->flags & BB_REACHABLE)) {
82 for (j = 0; j < bb->in_count; j++) {
83 unlink_target (bb->in_bb [j], bb);
85 for (j = 0; j < bb->out_count; j++) {
86 unlink_target (bb, bb->out_bb [j]);
96 replace_usage (MonoCompile *cfg, MonoBasicBlock *bb, MonoInst *inst, MonoInst **stack)
103 arity = mono_burg_arity [inst->opcode];
105 if ((inst->ssa_op == MONO_SSA_LOAD || inst->ssa_op == MONO_SSA_ADDRESS_TAKEN) &&
106 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG)) {
108 int idx = inst->inst_i0->inst_c0;
111 new_var = stack [idx];
113 new_var = cfg->varinfo [idx];
115 if ((new_var->opcode != OP_ARG) && (new_var->opcode != OP_LOCAL)) {
116 /* uninitialized variable ? */
117 g_warning ("using uninitialized variables %d in BB%d (%s)", idx, bb->block_num,
118 mono_method_full_name (cfg->method, TRUE));
119 //g_assert_not_reached ();
123 printf ("REPLACE BB%d %d %d\n", bb->block_num, idx, new_var->inst_c0);
125 inst->inst_i0 = new_var;
129 if (inst->ssa_op != MONO_SSA_STORE)
130 replace_usage (cfg, bb, inst->inst_left, stack);
132 replace_usage (cfg, bb, inst->inst_right, stack);
138 extends_live (MonoInst *inst)
145 arity = mono_burg_arity [inst->opcode];
147 if (inst->ssa_op == MONO_SSA_LOAD &&
148 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG)) {
152 if (inst->ssa_op != MONO_SSA_STORE)
153 if (extends_live (inst->inst_left))
156 if (extends_live (inst->inst_right))
165 replace_usage_new (MonoCompile *cfg, MonoInst *inst, int varnum, MonoInst *rep)
172 arity = mono_burg_arity [inst->opcode];
174 if ((inst->ssa_op == MONO_SSA_LOAD) &&
175 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG) &&
176 inst->inst_i0->inst_c0 == varnum && rep->type == inst->type) {
181 if (inst->ssa_op != MONO_SSA_STORE)
182 if (replace_usage_new (cfg, inst->inst_left, varnum, rep))
185 if (replace_usage_new (cfg, inst->inst_right, varnum, rep))
194 mono_ssa_rename_vars (MonoCompile *cfg, int max_vars, MonoBasicBlock *bb, MonoInst **stack)
196 MonoInst *inst, *new_var;
199 MonoInst **new_stack;
202 printf ("RENAME VARS BB%d %s\n", bb->block_num, mono_method_full_name (cfg->method, TRUE));
205 for (inst = bb->code; inst; inst = inst->next) {
206 if (inst->opcode != OP_PHI)
207 replace_usage (cfg, bb, inst, stack);
209 if (inst->ssa_op == MONO_SSA_STORE &&
210 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG)) {
211 idx = inst->inst_i0->inst_c0;
212 g_assert (idx < max_vars);
214 if ((!stack [idx]) && (bb == cfg->bb_init) && (inst->inst_i0->opcode != OP_ARG)) {
215 new_var = cfg->varinfo [idx];
217 new_var = mono_compile_create_var (cfg, inst->inst_i0->inst_vtype, inst->inst_i0->opcode);
218 new_var->flags = inst->inst_i0->flags;
221 printf ("DEF %d %d\n", idx, new_var->inst_c0);
223 inst->inst_i0 = new_var;
225 #ifdef USE_ORIGINAL_VARS
226 cfg->vars [new_var->inst_c0]->reg = idx;
229 stack [idx] = new_var;
233 for (i = 0; i < bb->out_count; i++) {
234 MonoBasicBlock *n = bb->out_bb [i];
236 for (j = 0; j < n->in_count; j++)
237 if (n->in_bb [j] == bb)
240 for (inst = n->code; inst; inst = inst->next) {
241 if (inst->ssa_op == MONO_SSA_STORE && inst->inst_i1->opcode == OP_PHI) {
242 idx = inst->inst_i1->inst_c0;
244 new_var = stack [idx];
246 new_var = cfg->varinfo [idx];
248 printf ("FOUND PHI %d (%d, %d)\n", idx, j, new_var->inst_c0);
250 inst->inst_i1->inst_phi_args [j + 1] = new_var->inst_c0;
257 new_stack = g_new (MonoInst*, max_vars);
258 for (tmp = bb->dominated; tmp; tmp = tmp->next) {
259 memcpy (new_stack, stack, sizeof (MonoInst *) * max_vars);
260 mono_ssa_rename_vars (cfg, max_vars, (MonoBasicBlock *)tmp->data, new_stack);
267 mono_ssa_compute (MonoCompile *cfg)
271 MonoMethodVar *vinfo = g_new0 (MonoMethodVar, cfg->num_varinfo);
272 MonoInst *inst, *store, **stack;
274 g_assert (!(cfg->comp_done & MONO_COMP_SSA));
276 /* we dont support methods containing exception clauses */
277 g_assert (mono_method_get_header (cfg->method)->num_clauses == 0);
278 g_assert (!cfg->disable_ssa);
280 //printf ("COMPUTS SSA %s %d\n", mono_method_full_name (cfg->method, TRUE), cfg->num_varinfo);
282 #ifdef CREATE_PRUNED_SSA
283 /* we need liveness for pruned SSA */
284 if (!(cfg->comp_done & MONO_COMP_LIVENESS))
285 mono_analyze_liveness (cfg);
288 mono_compile_dominator_info (cfg, MONO_COMP_DOM | MONO_COMP_IDOM | MONO_COMP_DFRONTIER);
290 for (i = 0; i < cfg->num_varinfo; ++i) {
291 vinfo [i].def_in = mono_bitset_new (cfg->num_bblocks, 0);
293 /* implizit reference at start */
294 mono_bitset_set (vinfo [i].def_in, 0);
296 for (i = 0; i < cfg->num_bblocks; ++i) {
297 for (inst = cfg->bblocks [i]->code; inst; inst = inst->next) {
298 if (inst->ssa_op == MONO_SSA_STORE) {
299 idx = inst->inst_i0->inst_c0;
300 g_assert (idx < cfg->num_varinfo);
301 mono_bitset_set (vinfo [idx].def_in, i);
306 /* insert phi functions */
307 for (i = 0; i < cfg->num_varinfo; ++i) {
308 set = mono_compile_iterated_dfrontier (cfg, vinfo [i].def_in);
309 vinfo [i].dfrontier = set;
310 mono_bitset_foreach_bit (set, idx, cfg->num_bblocks) {
311 MonoBasicBlock *bb = cfg->bblocks [idx];
313 /* fixme: create pruned SSA? we would need liveness information for that */
315 if (bb == cfg->bb_exit)
318 if ((cfg->comp_done & MONO_COMP_LIVENESS) && !mono_bitset_test_fast (bb->live_in_set, i)) {
319 //printf ("%d is not live in BB%d %s\n", i, bb->block_num, mono_method_full_name (cfg->method, TRUE));
323 NEW_PHI (cfg, inst, i);
325 inst->inst_phi_args = mono_mempool_alloc0 (cfg->mempool, sizeof (int) * (cfg->bblocks [idx]->in_count + 1));
326 inst->inst_phi_args [0] = cfg->bblocks [idx]->in_count;
328 store = mono_mempool_alloc0 ((cfg)->mempool, sizeof (MonoInst));
329 if (!cfg->varinfo [i]->inst_vtype->type)
330 g_assert_not_reached ();
331 store->opcode = mono_type_to_stind (cfg->varinfo [i]->inst_vtype);
332 store->ssa_op = MONO_SSA_STORE;
333 store->inst_i0 = cfg->varinfo [i];
334 store->inst_i1 = inst;
335 store->klass = store->inst_i0->klass;
337 store->next = bb->code;
340 bb->last_ins = bb->code;
343 printf ("ADD PHI BB%d %s\n", cfg->bblocks [idx]->block_num, mono_method_full_name (cfg->method, TRUE));
349 for (i = 0; i < cfg->num_varinfo; ++i)
350 mono_bitset_free (vinfo [i].def_in);
354 stack = alloca (sizeof (MonoInst *) * cfg->num_varinfo);
356 for (i = 0; i < cfg->num_varinfo; i++)
359 mono_ssa_rename_vars (cfg, cfg->num_varinfo, cfg->bb_entry, stack);
361 cfg->comp_done |= MONO_COMP_SSA;
364 #ifndef USE_ORIGINAL_VARS
366 mono_ssa_get_allocatable_vars (MonoCompile *cfg)
368 GHashTable *type_hash;
369 GPtrArray *varlist_array = g_ptr_array_new ();
372 g_assert (cfg->comp_done & MONO_COMP_LIVENESS);
374 type_hash = g_hash_table_new (NULL, NULL);
376 for (i = 0; i < cfg->num_varinfo; i++) {
377 MonoInst *ins = cfg->varinfo [i];
378 MonoMethodVar *vmv = MONO_VARINFO (cfg, i);
381 if (vmv->range.first_use.abs_pos > vmv->range.last_use.abs_pos)
384 if (ins->flags & (MONO_INST_VOLATILE|MONO_INST_INDIRECT) ||
385 (ins->opcode != OP_LOCAL && ins->opcode != OP_ARG) || vmv->reg != -1)
388 g_assert (ins->inst_vtype);
389 g_assert (vmv->reg == -1);
390 g_assert (i == vmv->idx);
392 if (!(tidx = (int)g_hash_table_lookup (type_hash, ins->inst_vtype))) {
393 GList *vars = g_list_append (NULL, vmv);
394 g_ptr_array_add (varlist_array, vars);
395 g_hash_table_insert (type_hash, ins->inst_vtype, (gpointer)varlist_array->len);
398 g_ptr_array_index (varlist_array, tidx) =
399 mono_varlist_insert_sorted (cfg, g_ptr_array_index (varlist_array, tidx), vmv, FALSE);
403 g_hash_table_destroy (type_hash);
405 return varlist_array;
410 mono_ssa_replace_copies (MonoCompile *cfg, MonoBasicBlock *bb, MonoInst *inst, char *is_live)
417 arity = mono_burg_arity [inst->opcode];
419 if ((inst->ssa_op == MONO_SSA_LOAD || inst->ssa_op == MONO_SSA_ADDRESS_TAKEN || inst->ssa_op == MONO_SSA_STORE) &&
420 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG)) {
422 int idx = inst->inst_i0->inst_c0;
423 MonoMethodVar *mv = cfg->vars [idx];
425 if (mv->reg != -1 && mv->reg != mv->idx) {
427 is_live [mv->reg] = 1;
429 new_var = cfg->varinfo [mv->reg];
432 printf ("REPLACE COPY BB%d %d %d\n", bb->block_num, idx, new_var->inst_c0);
433 g_assert (cfg->varinfo [mv->reg]->inst_vtype == cfg->varinfo [idx]->inst_vtype);
435 inst->inst_i0 = new_var;
437 is_live [mv->idx] = 1;
443 mono_ssa_replace_copies (cfg, bb, inst->inst_left, is_live);
445 mono_ssa_replace_copies (cfg, bb, inst->inst_right, is_live);
448 if (inst->ssa_op == MONO_SSA_STORE && inst->inst_i1->ssa_op == MONO_SSA_LOAD &&
449 inst->inst_i0->inst_c0 == inst->inst_i1->inst_i0->inst_c0) {
450 inst->ssa_op = MONO_SSA_NOP;
451 inst->opcode = CEE_NOP;
457 mono_ssa_remove (MonoCompile *cfg)
459 MonoInst *inst, *phi;
462 #ifndef USE_ORIGINAL_VARS
463 GPtrArray *varlist_array;
466 g_assert (cfg->comp_done & MONO_COMP_SSA);
468 for (i = 0; i < cfg->num_bblocks; ++i) {
469 MonoBasicBlock *bb = cfg->bblocks [i];
470 for (inst = bb->code; inst; inst = inst->next) {
471 if (inst->ssa_op == MONO_SSA_STORE && inst->inst_i1->opcode == OP_PHI) {
474 g_assert (phi->inst_phi_args [0] == bb->in_count);
476 for (j = 0; j < bb->in_count; j++) {
477 MonoBasicBlock *pred = bb->in_bb [j];
478 int idx = phi->inst_phi_args [j + 1];
479 MonoMethodVar *mv = cfg->vars [idx];
481 if (mv->reg != -1 && mv->reg != mv->idx) {
482 //printf ("PHICOPY %d %d -> %d\n", idx, mv->reg, inst->inst_i0->inst_c0);
487 if (idx != inst->inst_i0->inst_c0) {
489 printf ("MOVE %d to %d in BB%d\n", idx, inst->inst_i0->inst_c0, pred->block_num);
491 mono_add_varcopy_to_end (cfg, pred, idx, inst->inst_i0->inst_c0);
495 /* remove the phi functions */
496 inst->opcode = CEE_NOP;
497 inst->ssa_op = MONO_SSA_NOP;
502 #ifndef USE_ORIGINAL_VARS
503 /* we compute liveness again */
504 cfg->comp_done &= ~MONO_COMP_LIVENESS;
505 mono_analyze_liveness (cfg);
507 varlist_array = mono_ssa_get_allocatable_vars (cfg);
509 for (i = 0; i < varlist_array->len; i++) {
510 GList *l, *regs, *vars = g_ptr_array_index (varlist_array, i);
511 MonoMethodVar *vmv, *amv;
513 if (g_list_length (vars) <= 1) {
520 for (l = vars; l; l = l->next) {
523 /* expire old intervals in active */
525 amv = (MonoMethodVar *)active->data;
527 if (amv->range.last_use.abs_pos >= vmv->range.first_use.abs_pos)
530 active = g_list_delete_link (active, active);
531 regs = g_list_prepend (regs, (gpointer)amv->reg);
535 regs = g_list_prepend (regs, (gpointer)vmv->idx);
537 vmv->reg = (int)regs->data;
538 regs = g_list_delete_link (regs, regs);
539 active = mono_varlist_insert_sorted (cfg, active, vmv, TRUE);
542 g_list_free (active);
547 g_ptr_array_free (varlist_array, TRUE);
551 is_live = alloca (cfg->num_varinfo);
552 memset (is_live, 0, cfg->num_varinfo);
554 for (i = 0; i < cfg->num_bblocks; ++i) {
555 MonoBasicBlock *bb = cfg->bblocks [i];
557 for (inst = bb->code; inst; inst = inst->next)
558 mono_ssa_replace_copies (cfg, bb, inst, is_live);
561 for (i = 0; i < cfg->num_varinfo; ++i) {
562 cfg->vars [i]->reg = -1;
564 cfg->varinfo [i]->flags |= MONO_INST_IS_DEAD;
568 if (cfg->comp_done & MONO_COMP_REACHABILITY)
569 unlink_unused_bblocks (cfg);
571 cfg->comp_done &= ~MONO_COMP_SSA;
575 #define IS_CALL(op) (op == CEE_CALLI || op == CEE_CALL || op == CEE_CALLVIRT || (op >= OP_VOIDCALL && op <= OP_CALL_MEMBASE))
586 * Returns TRUE if the tree can have side effects.
589 analyze_dev_use (MonoCompile *cfg, MonoBasicBlock *bb, MonoInst *root, MonoInst *inst)
593 gboolean has_side_effects;
598 arity = mono_burg_arity [inst->opcode];
599 switch (inst->opcode) {
600 #define ANALYZE_DEV_USE_SPECIFIC_OPS 1
601 #define OPDEF(a1,a2,a3,a4,a5,a6,a7,a8,a9,a10) case a1:
602 #include "simple-cee-ops.h"
604 #define MINI_OP(a1,a2) case a1:
605 #include "simple-mini-ops.h"
607 #undef ANALYZE_DEV_USE_SPECIFIC_OPS
608 has_side_effects = FALSE;
611 has_side_effects = TRUE;
614 if ((inst->ssa_op == MONO_SSA_STORE) &&
615 (inst->inst_i0->opcode == OP_LOCAL /*|| inst->inst_i0->opcode == OP_ARG */)) {
616 idx = inst->inst_i0->inst_c0;
617 info = cfg->vars [idx];
618 //printf ("%d defined in BB%d %p\n", idx, bb->block_num, root);
620 g_warning ("more than one definition of variable %d in %s", idx,
621 mono_method_full_name (cfg->method, TRUE));
622 g_assert_not_reached ();
624 if (!IS_CALL (inst->inst_i1->opcode) /* && inst->inst_i1->opcode == OP_ICONST */) {
625 g_assert (inst == root);
630 if (inst->inst_i1->opcode == OP_PHI) {
631 for (i = inst->inst_i1->inst_phi_args [0]; i > 0; i--) {
632 MonoVarUsageInfo *ui = mono_mempool_alloc (cfg->mempool, sizeof (MonoVarUsageInfo));
633 idx = inst->inst_i1->inst_phi_args [i];
634 info = cfg->vars [idx];
635 //printf ("FOUND %d\n", idx);
638 info->uses = g_list_prepend_mempool (info->uses, cfg->mempool, ui);
643 if ((inst->ssa_op == MONO_SSA_LOAD || inst->ssa_op == MONO_SSA_ADDRESS_TAKEN) &&
644 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG)) {
645 MonoVarUsageInfo *ui = mono_mempool_alloc (cfg->mempool, sizeof (MonoVarUsageInfo));
646 idx = inst->inst_i0->inst_c0;
647 info = cfg->vars [idx];
648 //printf ("FOUND %d\n", idx);
651 info->uses = g_list_prepend_mempool (info->uses, cfg->mempool, ui);
654 //if (inst->ssa_op != MONO_SSA_STORE)
655 if (analyze_dev_use (cfg, bb, root, inst->inst_left))
656 has_side_effects = TRUE;
658 if (analyze_dev_use (cfg, bb, root, inst->inst_right))
659 has_side_effects = TRUE;
663 return has_side_effects;
667 /* avoid unnecessary copies of variables:
668 * Y <= X; Z = Y; is translated to Z = X;
671 mono_ssa_avoid_copies (MonoCompile *cfg)
673 MonoInst *inst, *next;
675 MonoMethodVar *i1, *i2;
677 g_assert ((cfg->comp_done & MONO_COMP_SSA_DEF_USE));
679 for (bb = cfg->bb_entry; bb; bb = bb->next_bb) {
680 for (inst = bb->code; inst; inst = inst->next) {
681 if (inst->ssa_op == MONO_SSA_STORE && inst->inst_i0->opcode == OP_LOCAL &&
682 !IS_CALL (inst->inst_i1->opcode) && inst->inst_i1->opcode != OP_PHI && !inst->flags) {
683 i1 = cfg->vars [inst->inst_i0->inst_c0];
685 /* fixme: compiling mcs does not work when I enable this */
687 if (g_list_length (i1->uses) == 1 && !extends_live (inst->inst_i1)) {
688 MonoVarUsageInfo *vi = (MonoVarUsageInfo *)i1->uses->data;
691 //printf ("VAR %d %s\n", i1->idx, mono_method_full_name (cfg->method, TRUE));
692 //mono_print_tree (inst); printf ("\n");
693 //mono_print_tree (u); printf ("\n");
695 if (replace_usage_new (cfg, u, inst->inst_i0->inst_c0, inst->inst_i1)) {
697 //mono_print_tree (u); printf ("\n");
699 inst->opcode = CEE_NOP;
700 inst->ssa_op = MONO_SSA_NOP;
704 if ((next = inst->next) && next->ssa_op == MONO_SSA_STORE && next->inst_i0->opcode == OP_LOCAL &&
705 next->inst_i1->ssa_op == MONO_SSA_LOAD && next->inst_i1->inst_i0->opcode == OP_LOCAL &&
706 next->inst_i1->inst_i0->inst_c0 == inst->inst_i0->inst_c0 && g_list_length (i1->uses) == 1 &&
707 inst->opcode == next->opcode && inst->inst_i0->type == next->inst_i0->type) {
708 i2 = cfg->vars [next->inst_i0->inst_c0];
709 //printf ("ELIM. COPY in BB%d %s\n", bb->block_num, mono_method_full_name (cfg->method, TRUE));
710 inst->inst_i0 = next->inst_i0;
714 next->opcode = CEE_NOP;
715 next->ssa_op = MONO_SSA_NOP;
723 mono_ssa_create_def_use (MonoCompile *cfg)
727 g_assert (!(cfg->comp_done & MONO_COMP_SSA_DEF_USE));
729 for (bb = cfg->bb_entry; bb; bb = bb->next_bb) {
731 for (inst = bb->code; inst; inst = inst->next) {
732 gboolean has_side_effects = analyze_dev_use (cfg, bb, inst, inst);
733 if (has_side_effects && (inst->ssa_op == MONO_SSA_STORE) &&
734 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG)) {
735 inst->inst_i0->flags |= MONO_INST_DEFINITION_HAS_SIDE_EFFECTS;
740 cfg->comp_done |= MONO_COMP_SSA_DEF_USE;
744 simulate_compare (int opcode, int a, int b)
760 return (unsigned)a >= (unsigned)b;
762 return (unsigned)a > (unsigned)b;
764 return (unsigned)a <= (unsigned)b;
766 return (unsigned)a < (unsigned)b;
768 g_assert_not_reached ();
775 simulate_long_compare (int opcode, gint64 a, gint64 b)
791 return (guint64)a >= (guint64)b;
793 return (guint64)a > (guint64)b;
795 return (guint64)a <= (guint64)b;
797 return (guint64)a < (guint64)b;
799 g_assert_not_reached ();
805 #define EVAL_CXX(name,op,cast) \
807 if ((inst->inst_i0->opcode == OP_COMPARE) || (inst->inst_i0->opcode == OP_LCOMPARE)) { \
808 r1 = evaluate_const_tree (cfg, inst->inst_i0->inst_i0, &a, carray); \
809 r2 = evaluate_const_tree (cfg, inst->inst_i0->inst_i1, &b, carray); \
810 if (r1 == 1 && r2 == 1) { \
811 *res = ((cast)a op (cast)b); \
814 return MAX (r1, r2); \
819 #define EVAL_BINOP(name,op) \
821 r1 = evaluate_const_tree (cfg, inst->inst_i0, &a, carray); \
822 r2 = evaluate_const_tree (cfg, inst->inst_i1, &b, carray); \
823 if (r1 == 1 && r2 == 1) { \
827 return MAX (r1, r2); \
832 /* fixme: this only works for interger constants, but not for other types (long, float) */
834 evaluate_const_tree (MonoCompile *cfg, MonoInst *inst, int *res, MonoInst **carray)
842 if (inst->ssa_op == MONO_SSA_LOAD &&
843 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG) &&
844 (c0 = carray [inst->inst_i0->inst_c0])) {
849 switch (inst->opcode) {
851 *res = inst->inst_c0;
854 EVAL_CXX (OP_CEQ,==,gint32)
855 EVAL_CXX (OP_CGT,>,gint32)
856 EVAL_CXX (OP_CGT_UN,>,guint32)
857 EVAL_CXX (OP_CLT,<,gint32)
858 EVAL_CXX (OP_CLT_UN,<,guint32)
860 EVAL_BINOP (CEE_ADD,+)
861 EVAL_BINOP (CEE_SUB,-)
862 EVAL_BINOP (CEE_MUL,*)
863 EVAL_BINOP (CEE_AND,&)
864 EVAL_BINOP (CEE_OR,|)
865 EVAL_BINOP (CEE_XOR,^)
866 EVAL_BINOP (CEE_SHL,<<)
867 EVAL_BINOP (CEE_SHR,>>)
877 fold_tree (MonoCompile *cfg, MonoBasicBlock *bb, MonoInst *inst, MonoInst **carray)
885 arity = mono_burg_arity [inst->opcode];
887 if (inst->ssa_op == MONO_SSA_STORE &&
888 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG) &&
889 inst->inst_i1->opcode == OP_PHI && (c0 = carray [inst->inst_i0->inst_c0])) {
890 //{static int cn = 0; printf ("PHICONST %d %d %s\n", cn++, c0->inst_c0, mono_method_full_name (cfg->method, TRUE));}
891 *inst->inst_i1 = *c0;
892 } else if (inst->ssa_op == MONO_SSA_LOAD &&
893 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG) &&
894 (c0 = carray [inst->inst_i0->inst_c0])) {
895 //{static int cn = 0; printf ("YCCOPY %d %d %s\n", cn++, c0->inst_c0, mono_method_full_name (cfg->method, TRUE));}
900 fold_tree (cfg, bb, inst->inst_left, carray);
902 fold_tree (cfg, bb, inst->inst_right, carray);
903 mono_constant_fold_inst (inst, NULL);
907 if ((inst->opcode >= CEE_BEQ && inst->opcode <= CEE_BLT_UN) &&
908 ((inst->inst_i0->opcode == OP_COMPARE) || (inst->inst_i0->opcode == OP_LCOMPARE))) {
909 MonoInst *v0 = inst->inst_i0->inst_i0;
910 MonoInst *v1 = inst->inst_i0->inst_i1;
911 MonoBasicBlock *target = NULL;
913 /* hack for longs to optimize the simply cases */
914 if (v0->opcode == OP_I8CONST && v1->opcode == OP_I8CONST) {
915 if (simulate_long_compare (inst->opcode, v0->inst_l, v1->inst_l)) {
916 //unlink_target (bb, inst->inst_false_bb);
917 target = inst->inst_true_bb;
919 //unlink_target (bb, inst->inst_true_bb);
920 target = inst->inst_false_bb;
922 } else if (evaluate_const_tree (cfg, v0, &a, carray) == 1 &&
923 evaluate_const_tree (cfg, v1, &b, carray) == 1) {
924 if (simulate_compare (inst->opcode, a, b)) {
925 //unlink_target (bb, inst->inst_false_bb);
926 target = inst->inst_true_bb;
928 //unlink_target (bb, inst->inst_true_bb);
929 target = inst->inst_false_bb;
934 bb->out_bb [0] = target;
936 inst->opcode = CEE_BR;
937 inst->inst_target_bb = target;
939 } else if (inst->opcode == CEE_SWITCH && (evaluate_const_tree (cfg, inst->inst_left, &a, carray) == 1) && (a >= 0) && (a < GPOINTER_TO_INT (inst->klass))) {
940 bb->out_bb [0] = inst->inst_many_bb [a];
942 inst->inst_target_bb = bb->out_bb [0];
943 inst->opcode = CEE_BR;
949 change_varstate (MonoCompile *cfg, GList **cvars, MonoMethodVar *info, int state, MonoInst *c0, MonoInst **carray)
951 if (info->cpstate >= state)
954 info->cpstate = state;
956 //printf ("SETSTATE %d to %d\n", info->idx, info->cpstate);
959 carray [info->idx] = c0;
961 carray [info->idx] = NULL;
963 if (!g_list_find (*cvars, info)) {
964 *cvars = g_list_prepend (*cvars, info);
969 visit_inst (MonoCompile *cfg, MonoBasicBlock *bb, MonoInst *inst, GList **cvars, GList **bblist, MonoInst **carray)
973 if (inst->opcode == CEE_SWITCH) {
975 int cases = GPOINTER_TO_INT (inst->klass);
977 r1 = evaluate_const_tree (cfg, inst->inst_left, &a, carray);
978 if ((r1 == 1) && ((a < 0) || (a >= cases)))
981 MonoBasicBlock *tb = inst->inst_many_bb [a];
982 if (!(tb->flags & BB_REACHABLE)) {
983 tb->flags |= BB_REACHABLE;
984 *bblist = g_list_prepend (*bblist, tb);
986 } else if (r1 == 2) {
987 for (i = GPOINTER_TO_INT (inst->klass); i >= 0; i--) {
988 MonoBasicBlock *tb = inst->inst_many_bb [i];
989 if (!(tb->flags & BB_REACHABLE)) {
990 tb->flags |= BB_REACHABLE;
991 *bblist = g_list_prepend (*bblist, tb);
995 } else if ((inst->opcode >= CEE_BEQ && inst->opcode <= CEE_BLT_UN) &&
996 ((inst->inst_i0->opcode == OP_COMPARE) || (inst->inst_i0->opcode == OP_LCOMPARE))) {
998 MonoInst *v0 = inst->inst_i0->inst_i0;
999 MonoInst *v1 = inst->inst_i0->inst_i1;
1001 r1 = evaluate_const_tree (cfg, v0, &a, carray);
1002 r2 = evaluate_const_tree (cfg, v1, &b, carray);
1004 if (r1 == 1 && r2 == 1) {
1005 MonoBasicBlock *target;
1007 if (simulate_compare (inst->opcode, a, b)) {
1008 target = inst->inst_true_bb;
1010 target = inst->inst_false_bb;
1012 if (!(target->flags & BB_REACHABLE)) {
1013 target->flags |= BB_REACHABLE;
1014 *bblist = g_list_prepend (*bblist, target);
1016 } else if (r1 == 2 || r2 == 2) {
1017 if (!(inst->inst_true_bb->flags & BB_REACHABLE)) {
1018 inst->inst_true_bb->flags |= BB_REACHABLE;
1019 *bblist = g_list_prepend (*bblist, inst->inst_true_bb);
1021 if (!(inst->inst_false_bb->flags & BB_REACHABLE)) {
1022 inst->inst_false_bb->flags |= BB_REACHABLE;
1023 *bblist = g_list_prepend (*bblist, inst->inst_false_bb);
1026 } else if (inst->ssa_op == MONO_SSA_STORE &&
1027 (inst->inst_i0->opcode == OP_LOCAL || inst->inst_i0->opcode == OP_ARG)) {
1028 MonoMethodVar *info = cfg->vars [inst->inst_i0->inst_c0];
1029 MonoInst *i1 = inst->inst_i1;
1032 if (info->cpstate < 2) {
1033 if (i1->opcode == OP_ICONST) {
1034 change_varstate (cfg, cvars, info, 1, i1, carray);
1035 } else if (i1->opcode == OP_PHI) {
1036 MonoInst *c0 = NULL;
1039 for (j = 1; j <= i1->inst_phi_args [0]; j++) {
1040 MonoMethodVar *mv = cfg->vars [i1->inst_phi_args [j]];
1041 MonoInst *src = mv->def;
1043 if (mv->def_bb && !(mv->def_bb->flags & BB_REACHABLE)) {
1047 if (!mv->def || !src || src->ssa_op != MONO_SSA_STORE ||
1048 !(src->inst_i0->opcode == OP_LOCAL || src->inst_i0->opcode == OP_ARG) ||
1050 change_varstate (cfg, cvars, info, 2, NULL, carray);
1054 if (mv->cpstate == 0)
1057 //g_assert (src->inst_i1->opcode == OP_ICONST);
1058 g_assert (carray [mv->idx]);
1061 c0 = carray [mv->idx];
1064 if (carray [mv->idx]->inst_c0 != c0->inst_c0) {
1065 change_varstate (cfg, cvars, info, 2, NULL, carray);
1070 if (c0 && info->cpstate < 1) {
1071 change_varstate (cfg, cvars, info, 1, c0, carray);
1074 int state = evaluate_const_tree (cfg, i1, &res, carray);
1076 NEW_ICONST (cfg, i1, res);
1077 change_varstate (cfg, cvars, info, 1, i1, carray);
1079 change_varstate (cfg, cvars, info, 2, NULL, carray);
1087 mono_ssa_cprop (MonoCompile *cfg)
1091 GList *bblock_list, *cvars;
1094 //printf ("SIMPLE OPTS BB%d %s\n", bb->block_num, mono_method_full_name (cfg->method, TRUE));
1096 carray = g_new0 (MonoInst*, cfg->num_varinfo);
1098 if (!(cfg->comp_done & MONO_COMP_SSA_DEF_USE))
1099 mono_ssa_create_def_use (cfg);
1101 bblock_list = g_list_prepend (NULL, cfg->bb_entry);
1102 cfg->bb_entry->flags |= BB_REACHABLE;
1104 memset (carray, 0, sizeof (MonoInst *) * cfg->num_varinfo);
1106 for (i = 0; i < cfg->num_varinfo; i++) {
1107 MonoMethodVar *info = cfg->vars [i];
1114 while (bblock_list) {
1117 bb = (MonoBasicBlock *)bblock_list->data;
1119 bblock_list = g_list_delete_link (bblock_list, bblock_list);
1121 g_assert (bb->flags & BB_REACHABLE);
1123 if (bb->out_count == 1) {
1124 if (!(bb->out_bb [0]->flags & BB_REACHABLE)) {
1125 bb->out_bb [0]->flags |= BB_REACHABLE;
1126 bblock_list = g_list_prepend (bblock_list, bb->out_bb [0]);
1130 for (inst = bb->code; inst; inst = inst->next) {
1131 visit_inst (cfg, bb, inst, &cvars, &bblock_list, carray);
1135 MonoMethodVar *info = (MonoMethodVar *)cvars->data;
1136 cvars = g_list_delete_link (cvars, cvars);
1138 for (tmp = info->uses; tmp; tmp = tmp->next) {
1139 MonoVarUsageInfo *ui = (MonoVarUsageInfo *)tmp->data;
1140 if (!(ui->bb->flags & BB_REACHABLE))
1142 visit_inst (cfg, ui->bb, ui->inst, &cvars, &bblock_list, carray);
1147 for (bb = cfg->bb_entry->next_bb; bb; bb = bb->next_bb) {
1149 for (inst = bb->code; inst; inst = inst->next) {
1150 fold_tree (cfg, bb, inst, carray);
1156 cfg->comp_done |= MONO_COMP_REACHABILITY;
1160 add_to_dce_worklist (MonoCompile *cfg, MonoMethodVar *var, MonoMethodVar *use, GList **wl)
1164 *wl = g_list_prepend (*wl, use);
1166 for (tmp = use->uses; tmp; tmp = tmp->next) {
1167 MonoVarUsageInfo *ui = (MonoVarUsageInfo *)tmp->data;
1168 if (ui->inst == var->def) {
1169 /* from the mempool */
1170 use->uses = g_list_remove_link (use->uses, tmp);
1177 mono_ssa_deadce (MonoCompile *cfg)
1182 g_assert (cfg->comp_done & MONO_COMP_SSA);
1184 //printf ("DEADCE %s\n", mono_method_full_name (cfg->method, TRUE));
1186 /* fixme: we should update usage infos during cprop, instead of computing it again */
1187 cfg->comp_done &= ~MONO_COMP_SSA_DEF_USE;
1188 for (i = 0; i < cfg->num_varinfo; i++) {
1189 MonoMethodVar *info = cfg->vars [i];
1194 if (!(cfg->comp_done & MONO_COMP_SSA_DEF_USE))
1195 mono_ssa_create_def_use (cfg);
1197 mono_ssa_avoid_copies (cfg);
1200 for (i = 0; i < cfg->num_varinfo; i++) {
1201 MonoMethodVar *info = cfg->vars [i];
1202 work_list = g_list_prepend (work_list, info);
1204 //if ((info->def != NULL) && (info->def->inst_i1->opcode != OP_PHI)) printf ("SSA DEADCE TOTAL LOCAL\n");
1208 MonoMethodVar *info = (MonoMethodVar *)work_list->data;
1209 work_list = g_list_delete_link (work_list, work_list);
1211 if (!info->uses && info->def && (!(cfg->varinfo [info->idx]->flags & (MONO_INST_DEFINITION_HAS_SIDE_EFFECTS|MONO_INST_VOLATILE|MONO_INST_INDIRECT)))) {
1213 //printf ("ELIMINATE %s: ", mono_method_full_name (cfg->method, TRUE)); mono_print_tree (info->def); printf ("\n");
1215 i1 = info->def->inst_i1;
1216 if (i1->opcode == OP_PHI) {
1218 for (j = i1->inst_phi_args [0]; j > 0; j--) {
1219 MonoMethodVar *u = cfg->vars [i1->inst_phi_args [j]];
1220 add_to_dce_worklist (cfg, info, u, &work_list);
1222 } else if (i1->ssa_op == MONO_SSA_LOAD &&
1223 (i1->inst_i0->opcode == OP_LOCAL || i1->inst_i0->opcode == OP_ARG)) {
1224 MonoMethodVar *u = cfg->vars [i1->inst_i0->inst_c0];
1225 add_to_dce_worklist (cfg, info, u, &work_list);
1227 //if (i1->opcode != OP_PHI) printf ("SSA DEADCE DEAD LOCAL\n");
1229 info->def->opcode = CEE_NOP;
1230 info->def->ssa_op = MONO_SSA_NOP;
1238 mono_ssa_strength_reduction (MonoCompile *cfg)
1243 g_assert (cfg->comp_done & MONO_COMP_SSA);
1244 g_assert (cfg->comp_done & MONO_COMP_LOOPS);
1245 g_assert (cfg->comp_done & MONO_COMP_SSA_DEF_USE);
1247 for (bb = cfg->bb_entry->next_bb; bb; bb = bb->next_bb) {
1248 GList *lp = bb->loop_blocks;
1251 MonoBasicBlock *h = (MonoBasicBlock *)lp->data;
1253 /* we only consider loops with 2 in bblocks */
1254 if (!h->in_count == 2)
1257 for (i = 0; i < cfg->num_varinfo; i++) {
1258 MonoMethodVar *info = cfg->vars [i];
1260 if (info->def && info->def->ssa_op == MONO_SSA_STORE &&
1261 info->def->inst_i0->opcode == OP_LOCAL && g_list_find (lp, info->def_bb)) {
1262 MonoInst *v = info->def->inst_i1;
1265 printf ("FOUND %d in %s\n", info->idx, mono_method_full_name (cfg->method, TRUE));