4 * Copyright: (c) Universitaet Karlsruhe
5 * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
7 * Implementation of the RA-Interface for an external, (non-SSA) register allocator.
9 * The external register allocator is a program:
10 * PROG -i INPUTFILE -o OUTPUTFILE
12 * 1) Input file defines the interference graph
13 * 2) Output file contains the instructions to perform
18 ----------------------
20 inputfile ::= regs nodes interf affinities .
22 regs ::= 'regs' regcount . // Anzahl der register (0..regcount-1), die zur Verfuegung stehen
24 nodes ::= 'nodes' '{' node* '}' . // All nodes in the graph
27 | node-info '<' reg-nr '>' . // Reg-nr is present in case of constraints
29 node-info ::= node-nr spill-costs .
31 interf ::= 'interferences' '{' i-edge* '}' . // Interference edges of the graph
33 i-edge ::= '(' node-nr ',' node-nr ')' .
35 affinities ::= 'affinities' '{' a-edge* '}' . // Affinity edges of the graph
37 a-edge ::= '(' node-nr ',' node-nr ',' weight ')' .
40 weight, regcount, node-nr ::= int32 .
41 spill-costs ::= int32 . // negative spill costs indicate unspillable
43 The output file format
44 -----------------------
46 outputfile ::= spills | allocs .
48 spills ::= 'spills' node-nr+ .
50 allocs ::= 'allocs' alloc* .
52 alloc ::= node-nr reg-nr .
55 ******** End of file format docu ********/
72 #include <libcore/lc_opts.h>
73 #include <libcore/lc_opts_enum.h>
81 #include "irprintf_t.h"
83 #include "irgraph_t.h"
85 #include "iredges_t.h"
90 #include "beraextern.h"
95 #include "besched_t.h"
100 #include "bessadestrsimple.h"
105 * Environment with all the needed stuff
107 typedef struct _be_raext_env_t {
109 const arch_register_class_t *cls;
113 FILE *f; /**< file handle used for out- and input file */
114 set *vars; /**< contains all be_var_info_t */
115 int n_cls_vars; /**< length of the array cls_vars */
116 be_var_info_t **cls_vars; /**< only the var_infos for current cls. needed for double iterating */
117 DEBUG_ONLY(firm_dbg_module_t *dbg;)
122 /******************************************************************************
125 | |__| | ___| |_ __ ___ _ __ ___
126 | __ |/ _ \ | '_ \ / _ \ '__/ __|
127 | | | | __/ | |_) | __/ | \__ \
128 |_| |_|\___|_| .__/ \___|_| |___/
131 *****************************************************************************/
134 #define pset_foreach(pset, irn) for(irn=pset_first(pset); irn; irn=pset_next(pset))
135 #define set_foreach(set, e) for(e=set_first(set); e; e=set_next(set))
138 * Checks if _the_ result of the irn belongs to the
139 * current register class (raenv->cls)
140 * NOTE: Only the first result is checked.
142 #define is_res_in_reg_class(irn) arch_irn_has_reg_class(raenv->aenv, irn, -1, raenv->cls)
144 static INLINE ir_node *get_first_non_phi(pset *s) {
153 assert(0 && "There must be a non-phi-irn in this");
157 static INLINE ir_node *get_first_phi(pset *s) {
166 assert(0 && "There must be a phi in this");
170 static int get_loop_weight(ir_node *irn) {
172 ir_loop *loop = get_irn_loop(get_nodes_block(irn));
175 int d = get_loop_depth(loop);
181 #define get_const_weight(irn) (1)
183 #define get_spill_weight(irn) get_loop_weight(irn)
184 #define get_reload_weight(irn) get_loop_weight(irn)
185 #define get_affinity_weight(irn) get_loop_weight(irn)
187 /******************************************************************************
189 / ____| | | / ____| (_)
190 | | ___ _ __ ___| |_ _ __ | | ___ _ __ _ ___ ___
191 | | / _ \| '_ \/ __| __| '__| | | / _ \| '_ \| |/ _ \/ __|
192 | |___| (_) | | | \__ \ |_| | | |___| (_) | |_) | | __/\__ \
193 \_____\___/|_| |_|___/\__|_| \_____\___/| .__/|_|\___||___/
196 *****************************************************************************/
198 static void handle_constraints_insn(be_raext_env_t *env, be_insn_t *insn)
200 ir_node *bl = get_nodes_block(insn->irn);
203 for(i = 0; i < insn->use_start; ++i) {
204 be_operand_t *op = &insn->ops[i];
206 if(op->has_constraints) {
207 ir_node *cpy = be_new_Copy(op->req.cls, env->irg, bl, op->carrier);
208 sched_add_before(insn->next_insn, cpy);
209 edges_reroute(op->carrier, cpy, env->irg);
213 for(i = insn->use_start; i < insn->n_ops; ++i) {
214 be_operand_t *op = &insn->ops[i];
216 if(op->has_constraints) {
217 ir_node *cpy = be_new_Copy(op->req.cls, env->irg, bl, op->carrier);
218 sched_add_before(insn->irn, cpy);
219 set_irn_n(insn->irn, op->pos, cpy);
220 be_set_constr_limited(cpy, BE_OUT_POS(0), &op->req);
225 static void handle_constraints_block(ir_node *bl, void *data)
227 be_raext_env_t *raenv = data;
228 int active = bl != get_irg_start_block(raenv->irg);
235 ie.aenv = raenv->aenv;
237 ie.ignore_colors = NULL;
240 irn = sched_first(bl);
241 while(!sched_is_end(irn)) {
242 be_insn_t *insn = be_scan_insn(&ie, irn);
244 if(insn->has_constraints)
245 handle_constraints_insn(raenv, insn);
247 if(be_is_Barrier(irn))
250 irn = insn->next_insn;
251 obstack_free(&obst, insn);
255 static void handle_constraints(be_raext_env_t *raenv) {
256 irg_block_walk_graph(raenv->irg, NULL, handle_constraints_block, raenv);
262 /******************************************************************************
265 | | | |_ _ _ __ ___ _ __ ___ _ __
266 | | | | | | | '_ ` _ \| '_ \ / _ \ '__|
267 | |__| | |_| | | | | | | |_) | __/ |
268 |_____/ \__,_|_| |_| |_| .__/ \___|_|
271 *****************************************************************************/
274 static void extract_vars_of_cls(be_raext_env_t *raenv) {
278 raenv->cls_vars = xmalloc(set_count(raenv->vars) * sizeof(*raenv->cls_vars));
279 assert(raenv->cls_vars);
281 set_foreach(raenv->vars, vi)
282 if (is_res_in_reg_class(get_first_non_phi(vi->values)))
283 raenv->cls_vars[count++] = vi;
285 raenv->cls_vars = realloc(raenv->cls_vars, count * sizeof(*raenv->cls_vars));
286 assert(raenv->cls_vars);
288 raenv->n_cls_vars = count;
293 * Check if node irn has a limited-constraint at position pos.
294 * If yes, dump it to FILE raenv->f
296 static INLINE void dump_constraint(be_raext_env_t *raenv, ir_node *irn, int pos) {
297 bitset_t *bs = bitset_alloca(raenv->cls->n_regs);
298 arch_register_req_t req;
300 arch_get_register_req(raenv->aenv, &req, irn, pos);
301 if (arch_register_req_is(&req, limited)) {
303 req.limited(req.limited_env, bs);
304 reg_nr = bitset_next_set(bs, 0);
305 fprintf(raenv->f, "<%d>", reg_nr);
306 assert(-1 == bitset_next_set(bs, reg_nr+1) && "Constraints with more than 1 possible register are not supported");
310 #define UNSPILLABLE -1
312 static INLINE int get_spill_costs(be_raext_env_t *raenv, be_var_info_t *vi) {
314 int c_spills=0, c_reloads=0;
316 pset_foreach(vi->values, irn) {
317 if (arch_irn_is(raenv->aenv, irn, ignore) || be_is_Reload(irn)) {
318 pset_break(vi->values);
323 /* number of reloads is the number of non-phi uses of all values of this var */
324 const ir_edge_t *edge;
325 foreach_out_edge(irn, edge)
326 if (!is_Phi(edge->src))
327 c_reloads += get_reload_weight(edge->src);
329 /* number of spills is the number of non-phi values for this var */
330 c_spills += get_spill_weight(irn);
334 return c_spills + c_reloads;
337 static void dump_nodes(be_raext_env_t *raenv) {
341 fprintf(f, "\nnodes {\n");
343 for (i=0; i<raenv->n_cls_vars; ++i) {
344 be_var_info_t *vi = raenv->cls_vars[i];
346 if (vi->var_nr == SET_REMOVED)
349 fprintf(f, "%d %d", vi->var_nr, get_spill_costs(raenv, vi));
350 dump_constraint(raenv, get_first_non_phi(vi->values), -1);
359 static void dump_interferences(be_raext_env_t *raenv) {
361 be_var_info_t *vi1, *vi2;
362 ir_node *irn1, *irn2;
364 be_lv_t *lv = raenv->birg->lv;
366 fprintf(f, "\ninterferences {\n");
368 for (i=0; i<raenv->n_cls_vars; ++i) {
369 vi1 = raenv->cls_vars[i];
371 if (vi1->var_nr == SET_REMOVED)
374 for (o=i+1; o<raenv->n_cls_vars; ++o) {
375 vi2 = raenv->cls_vars[o];
377 if (vi2->var_nr == SET_REMOVED)
380 pset_foreach(vi1->values, irn1)
381 pset_foreach(vi2->values, irn2)
382 if (values_interfere(lv, irn1, irn2)) {
383 pset_break(vi1->values);
384 pset_break(vi2->values);
385 fprintf(f, "(%d, %d)\n", vi1->var_nr, vi2->var_nr);
395 static void dump_affinities_walker(ir_node *irn, void *env) {
396 be_raext_env_t *raenv = env;
397 arch_register_req_t req;
399 be_var_info_t *vi1, *vi2;
401 if (arch_get_irn_reg_class(raenv->aenv, irn, -1) != raenv->cls || arch_irn_is(raenv->aenv, irn, ignore))
404 vi1 = be_get_var_info(irn);
406 /* copies have affinities */
407 if (arch_irn_class_is(raenv->aenv, irn, copy)) {
408 ir_node *other = be_get_Copy_op(irn);
410 if (! arch_irn_is(raenv->aenv, other, ignore)) {
411 vi2 = be_get_var_info(other);
413 fprintf(raenv->f, "(%d, %d, %d)\n", vi1->var_nr, vi2->var_nr, get_affinity_weight(irn));
418 /* should_be_equal constraints are affinites */
419 for (pos = 0, max = get_irn_arity(irn); pos<max; ++pos) {
420 arch_get_register_req(raenv->aenv, &req, irn, pos);
422 if (arch_register_req_is(&req, should_be_same) && arch_irn_is(raenv->aenv, req.other_same, ignore)) {
423 vi2 = be_get_var_info(req.other_same);
425 fprintf(raenv->f, "(%d, %d, %d)\n", vi1->var_nr, vi2->var_nr, get_affinity_weight(irn));
431 static void dump_affinities(be_raext_env_t *raenv) {
432 fprintf(raenv->f, "\naffinities {\n");
433 irg_walk_graph(raenv->irg, NULL, dump_affinities_walker, raenv);
434 fprintf(raenv->f, "}\n");
438 * Dump all information needed by the external
439 * register allocator to a single file.
441 static void dump_to_file(be_raext_env_t *raenv, char *filename) {
444 if (!(f = fopen(filename, "wt"))) {
445 fprintf(stderr, "Could not open file %s for writing\n", filename);
451 /* dump register info */
452 fprintf(f, "regs %d\n", arch_register_class_n_regs(raenv->cls));
454 /* dump the interference graph */
456 dump_interferences(raenv);
457 dump_affinities(raenv);
462 /******************************************************************************
465 | |__ __ _____ ___ _ _| |_ ___
466 | __| \ \/ / _ \/ __| | | | __/ _ \
467 | |____ > < __/ (__| |_| | || __/
468 |______/_/\_\___|\___|\__,_|\__\___|
469 *****************************************************************************/
472 * Execute the external register allocator specified in the
473 * firm-option firm.be.ra.ext.callee
475 static void execute(char *prog_to_call, char *out_file, char *result_file) {
479 snprintf(cmd_line, sizeof(cmd_line), "%s -i %s -o %s", prog_to_call, out_file, result_file);
480 cmd_line[sizeof(cmd_line) - 1] = '\0';
482 ret_status = system(cmd_line);
483 assert(ret_status != -1 && "Invokation of external register allocator failed");
484 assert(ret_status == 0 && "External register allocator is unhappy with sth.");
487 /******************************************************************************
490 / \ _ __ _ __ | |_ _ | |__) |___ ___ _ _| | |_
491 / /\ \ | '_ \| '_ \| | | | | | _ // _ \/ __| | | | | __|
492 / ____ \| |_) | |_) | | |_| | | | \ \ __/\__ \ |_| | | |_
493 /_/ \_\ .__/| .__/|_|\__, | |_| \_\___||___/\__,_|_|\__|
496 *****************************************************************************/
499 * Spill a variable and add reloads before all uses.
501 static INLINE void var_add_spills_and_reloads(be_raext_env_t *raenv, int var_nr) {
502 be_var_info_t *vi = be_var_find(raenv->vars, var_nr);
503 ir_node *spill=NULL, *ctx, *irn;
505 const ir_edge_t *edge, *ne;
506 pset *spills = pset_new_ptr(4); /* the spills of this variable */
507 pset *reloads = pset_new_ptr(4); /* the reloads of this variable */
508 be_lv_t *lv = raenv->birg->lv;
509 be_dom_front_info_t *dom_front = raenv->birg->dom_front;
510 int new_size, n_spills, n_reloads;
512 assert(vi && "Variable nr does not exist!");
513 assert(pset_count(vi->values) && "There are no values associated to this variable");
515 /* the spill context is set to an arbitrary node of the phi-class,
516 * or the node itself if it is not member of a phi class
518 if (pset_count(vi->values) == 1)
519 ctx = get_first_non_phi(vi->values);
521 ctx = get_first_phi(vi->values);
523 DBG((raenv->dbg, LEVEL_2, "Spill context: %+F\n", ctx));
525 /* for each value of this variable insert the spills */
526 pset_foreach(vi->values, irn) {
532 /* all ordinary nodes must be spilled */
533 DBG((raenv->dbg, LEVEL_2, " spilling %+F\n", irn));
534 spill = be_spill(raenv->aenv, irn);
536 /* remember the spill */
537 pset_insert_ptr(spills, spill);
540 assert(spill && "There must be at least one non-phi-node");
542 mode = get_irn_mode(get_irn_n(spill, be_pos_Spill_val));
544 /* insert reloads and wire them arbitrary*/
545 pset_foreach(vi->values, irn)
546 foreach_out_edge_safe(irn, edge, ne) {
547 ir_node *reload, *src = edge->src;
548 if (is_Phi(src) || be_is_Spill(src))
551 /* all real uses must be reloaded */
552 DBG((raenv->dbg, LEVEL_2, " reloading before %+F\n", src));
553 reload = be_reload(raenv->aenv, raenv->cls, edge->src, mode, spill);
554 set_irn_n(edge->src, edge->pos, reload);
556 /* remember the reload */
557 pset_insert_ptr(reloads, reload);
560 /* correct the reload->spill pointers... */
561 be_ssa_constr_set(dom_front, lv, spills);
564 /****** correct the variable <--> values mapping: ******
566 * - if we had a phi class it gets split into several new variables
567 * - all reloads are new variables
569 n_spills = pset_count(spills);
570 n_reloads = pset_count(reloads);
572 /* first make room for new pointers in the cls_var array */
573 new_size = raenv->n_cls_vars + n_reloads + ((n_spills>1) ? n_spills : 0);
574 raenv->cls_vars = realloc(raenv->cls_vars, (new_size) * sizeof(*raenv->cls_vars));
575 assert(raenv->cls_vars && "Out of mem!?");
577 /* if we had a real phi-class, we must... */
578 if (pset_count(spills) > 1) {
579 /* ...remove the old variable corresponding to the phi class */
580 vi->var_nr = SET_REMOVED;
582 /* ...add new vars for each non-phi-member */
583 pset_foreach(spills, irn) {
584 ir_node *spilled = get_irn_n(irn, be_pos_Spill_val);
585 raenv->cls_vars[raenv->n_cls_vars++] = be_var_add_value(raenv->vars, get_irn_node_nr(spilled), spilled);
589 /* add new variables for all reloads */
590 pset_foreach(reloads, irn) {
591 assert(get_irn_node_nr(irn) != 1089);
592 raenv->cls_vars[raenv->n_cls_vars++] = be_var_add_value(raenv->vars, get_irn_node_nr(irn), irn);
599 #define INVALID_FILE_FORMAT assert(0 && "Invalid file format.")
601 #define BUFCONV " %32s "
604 * Read in the actions performed by the external allocator.
605 * Apply these transformations to the irg.
606 * @return 1 if an allocation was read in. 0 otherwise.
608 static int read_and_apply_results(be_raext_env_t *raenv, char *filename) {
611 int is_allocation = 0;
613 if (!(f = fopen(filename, "rt"))) {
614 fprintf(stderr, "Could not open file %s for reading\n", filename);
620 /* read the action */
621 if (fscanf(f, BUFCONV, buf) != 1)
625 if (!strcmp(buf, "spills")) {
627 while (fscanf(f, " %d ", &var_nr) == 1)
628 var_add_spills_and_reloads(raenv, var_nr);
631 /* or do we allocate */
632 if (!strcmp(buf, "allocs")) {
636 while (fscanf(f, " %d %d ", &var_nr, ®_nr) == 2) {
638 pset *vals = be_get_var_values(raenv->vars, var_nr);
640 assert(vals && "Variable nr does not exist!");
641 pset_foreach(vals, irn)
642 arch_set_irn_register(raenv->aenv, irn, arch_register_for_index(raenv->cls, reg_nr));
652 return is_allocation;
655 static void check_allocation(be_raext_env_t *raenv) {
657 be_lv_t *lv = raenv->birg->lv;
659 for (i=0; i<raenv->n_cls_vars; ++i) {
660 be_var_info_t *vi1 = raenv->cls_vars[i];
662 if (vi1->var_nr == SET_REMOVED)
665 for (o=0; o<i; ++o) {
666 be_var_info_t *vi2 = raenv->cls_vars[o];
667 ir_node *irn1, *irn2;
669 if (vi2->var_nr == SET_REMOVED)
672 pset_foreach(vi1->values, irn1)
673 pset_foreach(vi2->values, irn2)
674 if (values_interfere(lv, irn1, irn2) && arch_get_irn_register(raenv->aenv, irn1) == arch_get_irn_register(raenv->aenv, irn2)) {
675 dump_ir_block_graph_sched(raenv->irg, "ERROR");
676 ir_fprintf(stdout, "SSA values %+F and %+F interfere. They belong to variable %d and %d respectively.\n", irn1, irn2, vi1->var_nr, vi2->var_nr);
677 assert(0 && "ERROR graph dumped");
683 /******************************************************************************
687 | |\/| |/ _` | | '_ \
688 | | | | (_| | | | | |
689 |_| |_|\__,_|_|_| |_|
690 *****************************************************************************/
693 * Default values for options
695 static char callee[128] = "\"E:/user/kimohoff/public/register allocator\"";
696 //static char callee[128] = "/ben/kimohoff/ipd-registerallocator/register_allocator";
700 * Allocate registers with an external program using a text-file interface.
702 * Do some computations (SSA-destruction and mapping of values--vars)
704 * Execute external program
705 * Read in results and apply them
708 static void be_ra_extern_main(be_irg_t *birg) {
709 be_main_env_t *env = birg->main_env;
710 ir_graph *irg = birg->irg;
712 be_raext_env_t raenv;
715 be_assure_dom_front(birg);
716 be_assure_liveness(birg);
721 raenv.aenv = env->arch_env;
722 FIRM_DBG_REGISTER(raenv.dbg, "firm.be.raextern");
724 /* Insert copies for constraints */
725 for(clsnr = 0, clss = arch_isa_get_n_reg_class(raenv.aenv->isa); clsnr < clss; ++clsnr) {
726 raenv.cls = arch_isa_get_reg_class(raenv.aenv->isa, clsnr);
727 handle_constraints(&raenv);
730 be_dump(irg, "-extern-constr", dump_ir_block_graph_sched);
732 /* SSA destruction respectively transformation into "Conventional SSA" */
733 raenv.vars = be_ssa_destr_simple(irg, env->arch_env);
734 be_dump(irg, "-extern-ssadestr", dump_ir_block_graph_sched);
737 /* For all register classes */
738 for(clsnr = 0, clss = arch_isa_get_n_reg_class(raenv.aenv->isa); clsnr < clss; ++clsnr) {
740 char out[256], in[256];
742 raenv.cls = arch_isa_get_reg_class(raenv.aenv->isa, clsnr);
744 extract_vars_of_cls(&raenv);
747 ir_snprintf(out, sizeof(out), "%F-%s-%d.ra", irg, raenv.cls->name, round);
748 ir_snprintf(in, sizeof(in), "%F-%s-%d.ra.res", irg, raenv.cls->name, round);
752 dump_to_file(&raenv, out);
753 execute(callee, out, in);
754 done = read_and_apply_results(&raenv, in);
755 be_abi_fix_stack_nodes(birg->abi, birg->lv);
757 ir_snprintf(in, sizeof(in), "-extern-%s-round-%d", raenv.cls->name, round);
758 be_dump(irg, in, dump_ir_block_graph_sched);
763 check_allocation(&raenv);
765 free(raenv.cls_vars);
768 be_dump(irg, "-extern-alloc", dump_ir_block_graph_sched);
771 free_ssa_destr_simple(raenv.vars);
773 be_invalidate_liveness(birg);
776 /******************************************************************************
779 | | | |_ __ | |_ _ ___ _ __ ___
780 | | | | '_ \| __| |/ _ \| '_ \/ __|
781 | |__| | |_) | |_| | (_) | | | \__ \
782 \____/| .__/ \__|_|\___/|_| |_|___/
785 *****************************************************************************/
790 static const lc_opt_enum_func_ptr_items_t ssa_destr_items[] = {
791 { "simple", (int (*)(void)) be_ssa_destr_simple }, /* TODO make (void*) casts nicer */
795 static set* (*ssa_destr)(ir_graph*,const arch_env_t*) = be_ssa_destr_simple;
797 static lc_opt_enum_func_ptr_var_t ssa_destr_var = {
798 (int (**)(void)) &ssa_destr, ssa_destr_items
801 static const lc_opt_table_entry_t be_ra_extern_options[] = {
802 LC_OPT_ENT_ENUM_FUNC_PTR("ssa_destr", "SSA destruction flavor", &ssa_destr_var),
803 LC_OPT_ENT_STR("callee", "The external program to call", callee, sizeof(callee)),
807 static be_ra_t be_ra_external_allocator = {
811 void be_init_raextern(void) {
812 lc_opt_entry_t *be_grp = lc_opt_get_grp(firm_opt_get_root(), "be");
813 lc_opt_entry_t *blocksched_grp = lc_opt_get_grp(be_grp, "ra");
814 lc_opt_entry_t *ext_grp = lc_opt_get_grp(blocksched_grp, "ext");
816 lc_opt_add_table(ext_grp, be_ra_extern_options);
818 be_register_allocator("ext", &be_ra_external_allocator);
820 BE_REGISTER_MODULE_CONSTRUCTOR(be_init_raextern);
822 #endif /* WITH_LIBCORE */