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 ********/
71 #include <libcore/lc_opts.h>
72 #include <libcore/lc_opts_enum.h>
79 #include "irprintf_t.h"
81 #include "irgraph_t.h"
83 #include "iredges_t.h"
88 #include "beraextern.h"
93 #include "besched_t.h"
98 #include "bessadestrsimple.h"
103 * Environment with all the needed stuff
105 typedef struct _be_raext_env_t {
107 const arch_register_class_t *cls;
111 FILE *f; /**< file handle used for out- and input file */
112 set *vars; /**< contains all be_var_info_t */
113 int n_cls_vars; /**< length of the array cls_vars */
114 be_var_info_t **cls_vars; /**< only the var_infos for current cls. needed for double iterating */
115 DEBUG_ONLY(firm_dbg_module_t *dbg;)
120 /******************************************************************************
123 | |__| | ___| |_ __ ___ _ __ ___
124 | __ |/ _ \ | '_ \ / _ \ '__/ __|
125 | | | | __/ | |_) | __/ | \__ \
126 |_| |_|\___|_| .__/ \___|_| |___/
129 *****************************************************************************/
132 #define pset_foreach(pset, irn) for(irn=pset_first(pset); irn; irn=pset_next(pset))
133 #define set_foreach(set, e) for(e=set_first(set); e; e=set_next(set))
136 * Checks if _the_ result of the irn belongs to the
137 * current register class (raenv->cls)
138 * NOTE: Only the first result is checked.
140 #define is_res_in_reg_class(irn) arch_irn_has_reg_class(raenv->aenv, irn, -1, raenv->cls)
142 static INLINE ir_node *get_first_non_phi(pset *s) {
151 assert(0 && "There must be a non-phi-irn in this");
155 static INLINE ir_node *get_first_phi(pset *s) {
164 assert(0 && "There must be a phi in this");
168 static int get_loop_weight(ir_node *irn) {
170 ir_loop *loop = get_irn_loop(get_nodes_block(irn));
173 int d = get_loop_depth(loop);
179 #define get_const_weight(irn) (1)
181 #define get_spill_weight(irn) get_loop_weight(irn)
182 #define get_reload_weight(irn) get_loop_weight(irn)
183 #define get_affinity_weight(irn) get_loop_weight(irn)
185 /******************************************************************************
187 / ____| | | / ____| (_)
188 | | ___ _ __ ___| |_ _ __ | | ___ _ __ _ ___ ___
189 | | / _ \| '_ \/ __| __| '__| | | / _ \| '_ \| |/ _ \/ __|
190 | |___| (_) | | | \__ \ |_| | | |___| (_) | |_) | | __/\__ \
191 \_____\___/|_| |_|___/\__|_| \_____\___/| .__/|_|\___||___/
194 *****************************************************************************/
196 static void handle_constraints_insn(be_raext_env_t *env, be_insn_t *insn)
198 ir_node *bl = get_nodes_block(insn->irn);
201 for(i = 0; i < insn->use_start; ++i) {
202 be_operand_t *op = &insn->ops[i];
204 if(op->has_constraints) {
205 ir_node *cpy = be_new_Copy(op->req.cls, env->irg, bl, op->carrier);
206 sched_add_before(insn->next_insn, cpy);
207 edges_reroute(op->carrier, cpy, env->irg);
211 for(i = insn->use_start; i < insn->n_ops; ++i) {
212 be_operand_t *op = &insn->ops[i];
214 if(op->has_constraints) {
215 ir_node *cpy = be_new_Copy(op->req.cls, env->irg, bl, op->carrier);
216 sched_add_before(insn->irn, cpy);
217 set_irn_n(insn->irn, op->pos, cpy);
218 be_set_constr_limited(cpy, BE_OUT_POS(0), &op->req);
223 static void handle_constraints_block(ir_node *bl, void *data)
225 be_raext_env_t *raenv = data;
226 int active = bl != get_irg_start_block(raenv->irg);
233 ie.aenv = raenv->aenv;
235 ie.ignore_colors = NULL;
238 irn = sched_first(bl);
239 while(!sched_is_end(irn)) {
240 be_insn_t *insn = be_scan_insn(&ie, irn);
242 if(insn->has_constraints)
243 handle_constraints_insn(raenv, insn);
245 if(be_is_Barrier(irn))
248 irn = insn->next_insn;
249 obstack_free(&obst, insn);
253 static void handle_constraints(be_raext_env_t *raenv) {
254 irg_block_walk_graph(raenv->irg, NULL, handle_constraints_block, raenv);
260 /******************************************************************************
263 | | | |_ _ _ __ ___ _ __ ___ _ __
264 | | | | | | | '_ ` _ \| '_ \ / _ \ '__|
265 | |__| | |_| | | | | | | |_) | __/ |
266 |_____/ \__,_|_| |_| |_| .__/ \___|_|
269 *****************************************************************************/
272 static void extract_vars_of_cls(be_raext_env_t *raenv) {
276 raenv->cls_vars = xmalloc(set_count(raenv->vars) * sizeof(*raenv->cls_vars));
277 assert(raenv->cls_vars);
279 set_foreach(raenv->vars, vi)
280 if (is_res_in_reg_class(get_first_non_phi(vi->values)))
281 raenv->cls_vars[count++] = vi;
283 raenv->cls_vars = realloc(raenv->cls_vars, count * sizeof(*raenv->cls_vars));
284 assert(raenv->cls_vars);
286 raenv->n_cls_vars = count;
291 * Check if node irn has a limited-constraint at position pos.
292 * If yes, dump it to FILE raenv->f
294 static INLINE void dump_constraint(be_raext_env_t *raenv, ir_node *irn, int pos) {
295 bitset_t *bs = bitset_alloca(raenv->cls->n_regs);
296 arch_register_req_t req;
298 arch_get_register_req(raenv->aenv, &req, irn, pos);
299 if (arch_register_req_is(&req, limited)) {
301 req.limited(req.limited_env, bs);
302 reg_nr = bitset_next_set(bs, 0);
303 fprintf(raenv->f, "<%d>", reg_nr);
304 assert(-1 == bitset_next_set(bs, reg_nr+1) && "Constraints with more than 1 possible register are not supported");
308 #define UNSPILLABLE -1
310 static INLINE int get_spill_costs(be_raext_env_t *raenv, be_var_info_t *vi) {
312 int c_spills=0, c_reloads=0;
314 pset_foreach(vi->values, irn) {
315 if (arch_irn_is(raenv->aenv, irn, ignore) || be_is_Reload(irn)) {
316 pset_break(vi->values);
321 /* number of reloads is the number of non-phi uses of all values of this var */
322 const ir_edge_t *edge;
323 foreach_out_edge(irn, edge)
324 if (!is_Phi(edge->src))
325 c_reloads += get_reload_weight(edge->src);
327 /* number of spills is the number of non-phi values for this var */
328 c_spills += get_spill_weight(irn);
332 return c_spills + c_reloads;
335 static void dump_nodes(be_raext_env_t *raenv) {
339 fprintf(f, "\nnodes {\n");
341 for (i=0; i<raenv->n_cls_vars; ++i) {
342 be_var_info_t *vi = raenv->cls_vars[i];
344 if (vi->var_nr == SET_REMOVED)
347 fprintf(f, "%d %d", vi->var_nr, get_spill_costs(raenv, vi));
348 dump_constraint(raenv, get_first_non_phi(vi->values), -1);
357 static void dump_interferences(be_raext_env_t *raenv) {
359 be_var_info_t *vi1, *vi2;
360 ir_node *irn1, *irn2;
362 be_lv_t *lv = raenv->birg->lv;
364 fprintf(f, "\ninterferences {\n");
366 for (i=0; i<raenv->n_cls_vars; ++i) {
367 vi1 = raenv->cls_vars[i];
369 if (vi1->var_nr == SET_REMOVED)
372 for (o=i+1; o<raenv->n_cls_vars; ++o) {
373 vi2 = raenv->cls_vars[o];
375 if (vi2->var_nr == SET_REMOVED)
378 pset_foreach(vi1->values, irn1)
379 pset_foreach(vi2->values, irn2)
380 if (values_interfere(lv, irn1, irn2)) {
381 pset_break(vi1->values);
382 pset_break(vi2->values);
383 fprintf(f, "(%d, %d)\n", vi1->var_nr, vi2->var_nr);
393 static void dump_affinities_walker(ir_node *irn, void *env) {
394 be_raext_env_t *raenv = env;
395 arch_register_req_t req;
397 be_var_info_t *vi1, *vi2;
399 if (arch_get_irn_reg_class(raenv->aenv, irn, -1) != raenv->cls || arch_irn_is(raenv->aenv, irn, ignore))
402 vi1 = be_get_var_info(irn);
404 /* copies have affinities */
405 if (arch_irn_class_is(raenv->aenv, irn, copy)) {
406 ir_node *other = be_get_Copy_op(irn);
408 if (! arch_irn_is(raenv->aenv, other, ignore)) {
409 vi2 = be_get_var_info(other);
411 fprintf(raenv->f, "(%d, %d, %d)\n", vi1->var_nr, vi2->var_nr, get_affinity_weight(irn));
416 /* should_be_equal constraints are affinites */
417 for (pos = 0, max = get_irn_arity(irn); pos<max; ++pos) {
418 arch_get_register_req(raenv->aenv, &req, irn, pos);
420 if (arch_register_req_is(&req, should_be_same) && arch_irn_is(raenv->aenv, req.other_same, ignore)) {
421 vi2 = be_get_var_info(req.other_same);
423 fprintf(raenv->f, "(%d, %d, %d)\n", vi1->var_nr, vi2->var_nr, get_affinity_weight(irn));
429 static void dump_affinities(be_raext_env_t *raenv) {
430 fprintf(raenv->f, "\naffinities {\n");
431 irg_walk_graph(raenv->irg, NULL, dump_affinities_walker, raenv);
432 fprintf(raenv->f, "}\n");
436 * Dump all information needed by the external
437 * register allocator to a single file.
439 static void dump_to_file(be_raext_env_t *raenv, char *filename) {
442 if (!(f = fopen(filename, "wt"))) {
443 fprintf(stderr, "Could not open file %s for writing\n", filename);
449 /* dump register info */
450 fprintf(f, "regs %d\n", arch_register_class_n_regs(raenv->cls));
452 /* dump the interference graph */
454 dump_interferences(raenv);
455 dump_affinities(raenv);
460 /******************************************************************************
463 | |__ __ _____ ___ _ _| |_ ___
464 | __| \ \/ / _ \/ __| | | | __/ _ \
465 | |____ > < __/ (__| |_| | || __/
466 |______/_/\_\___|\___|\__,_|\__\___|
467 *****************************************************************************/
470 * Execute the external register allocator specified in the
471 * firm-option firm.be.ra.ext.callee
473 static void execute(char *prog_to_call, char *out_file, char *result_file) {
477 snprintf(cmd_line, sizeof(cmd_line), "%s -i %s -o %s", prog_to_call, out_file, result_file);
478 cmd_line[sizeof(cmd_line) - 1] = '\0';
480 ret_status = system(cmd_line);
481 assert(ret_status != -1 && "Invokation of external register allocator failed");
482 assert(ret_status == 0 && "External register allocator is unhappy with sth.");
485 /******************************************************************************
488 / \ _ __ _ __ | |_ _ | |__) |___ ___ _ _| | |_
489 / /\ \ | '_ \| '_ \| | | | | | _ // _ \/ __| | | | | __|
490 / ____ \| |_) | |_) | | |_| | | | \ \ __/\__ \ |_| | | |_
491 /_/ \_\ .__/| .__/|_|\__, | |_| \_\___||___/\__,_|_|\__|
494 *****************************************************************************/
497 * Spill a variable and add reloads before all uses.
499 static INLINE void var_add_spills_and_reloads(be_raext_env_t *raenv, int var_nr) {
500 be_var_info_t *vi = be_var_find(raenv->vars, var_nr);
501 ir_node *spill=NULL, *ctx, *irn;
503 const ir_edge_t *edge, *ne;
504 pset *spills = pset_new_ptr(4); /* the spills of this variable */
505 pset *reloads = pset_new_ptr(4); /* the reloads of this variable */
506 be_lv_t *lv = raenv->birg->lv;
507 be_dom_front_info_t *dom_front = raenv->birg->dom_front;
508 int new_size, n_spills, n_reloads;
510 assert(vi && "Variable nr does not exist!");
511 assert(pset_count(vi->values) && "There are no values associated to this variable");
513 /* the spill context is set to an arbitrary node of the phi-class,
514 * or the node itself if it is not member of a phi class
516 if (pset_count(vi->values) == 1)
517 ctx = get_first_non_phi(vi->values);
519 ctx = get_first_phi(vi->values);
521 DBG((raenv->dbg, LEVEL_2, "Spill context: %+F\n", ctx));
523 /* for each value of this variable insert the spills */
524 pset_foreach(vi->values, irn) {
530 /* all ordinary nodes must be spilled */
531 DBG((raenv->dbg, LEVEL_2, " spilling %+F\n", irn));
532 spill = be_spill(raenv->aenv, irn);
534 /* remember the spill */
535 pset_insert_ptr(spills, spill);
538 assert(spill && "There must be at least one non-phi-node");
540 mode = get_irn_mode(get_irn_n(spill, be_pos_Spill_val));
542 /* insert reloads and wire them arbitrary*/
543 pset_foreach(vi->values, irn)
544 foreach_out_edge_safe(irn, edge, ne) {
545 ir_node *reload, *src = edge->src;
546 if (is_Phi(src) || be_is_Spill(src))
549 /* all real uses must be reloaded */
550 DBG((raenv->dbg, LEVEL_2, " reloading before %+F\n", src));
551 reload = be_reload(raenv->aenv, raenv->cls, edge->src, mode, spill);
552 set_irn_n(edge->src, edge->pos, reload);
554 /* remember the reload */
555 pset_insert_ptr(reloads, reload);
558 /* correct the reload->spill pointers... */
559 be_ssa_constr_set(dom_front, lv, spills);
562 /****** correct the variable <--> values mapping: ******
564 * - if we had a phi class it gets split into several new variables
565 * - all reloads are new variables
567 n_spills = pset_count(spills);
568 n_reloads = pset_count(reloads);
570 /* first make room for new pointers in the cls_var array */
571 new_size = raenv->n_cls_vars + n_reloads + ((n_spills>1) ? n_spills : 0);
572 raenv->cls_vars = realloc(raenv->cls_vars, (new_size) * sizeof(*raenv->cls_vars));
573 assert(raenv->cls_vars && "Out of mem!?");
575 /* if we had a real phi-class, we must... */
576 if (pset_count(spills) > 1) {
577 /* ...remove the old variable corresponding to the phi class */
578 vi->var_nr = SET_REMOVED;
580 /* ...add new vars for each non-phi-member */
581 pset_foreach(spills, irn) {
582 ir_node *spilled = get_irn_n(irn, be_pos_Spill_val);
583 raenv->cls_vars[raenv->n_cls_vars++] = be_var_add_value(raenv->vars, get_irn_node_nr(spilled), spilled);
587 /* add new variables for all reloads */
588 pset_foreach(reloads, irn) {
589 assert(get_irn_node_nr(irn) != 1089);
590 raenv->cls_vars[raenv->n_cls_vars++] = be_var_add_value(raenv->vars, get_irn_node_nr(irn), irn);
597 #define INVALID_FILE_FORMAT assert(0 && "Invalid file format.")
599 #define BUFCONV " %32s "
602 * Read in the actions performed by the external allocator.
603 * Apply these transformations to the irg.
604 * @return 1 if an allocation was read in. 0 otherwise.
606 static int read_and_apply_results(be_raext_env_t *raenv, char *filename) {
609 int is_allocation = 0;
611 if (!(f = fopen(filename, "rt"))) {
612 fprintf(stderr, "Could not open file %s for reading\n", filename);
618 /* read the action */
619 if (fscanf(f, BUFCONV, buf) != 1)
623 if (!strcmp(buf, "spills")) {
625 while (fscanf(f, " %d ", &var_nr) == 1)
626 var_add_spills_and_reloads(raenv, var_nr);
629 /* or do we allocate */
630 if (!strcmp(buf, "allocs")) {
634 while (fscanf(f, " %d %d ", &var_nr, ®_nr) == 2) {
636 pset *vals = be_get_var_values(raenv->vars, var_nr);
638 assert(vals && "Variable nr does not exist!");
639 pset_foreach(vals, irn)
640 arch_set_irn_register(raenv->aenv, irn, arch_register_for_index(raenv->cls, reg_nr));
650 return is_allocation;
653 static void check_allocation(be_raext_env_t *raenv) {
655 be_lv_t *lv = raenv->birg->lv;
657 for (i=0; i<raenv->n_cls_vars; ++i) {
658 be_var_info_t *vi1 = raenv->cls_vars[i];
660 if (vi1->var_nr == SET_REMOVED)
663 for (o=0; o<i; ++o) {
664 be_var_info_t *vi2 = raenv->cls_vars[o];
665 ir_node *irn1, *irn2;
667 if (vi2->var_nr == SET_REMOVED)
670 pset_foreach(vi1->values, irn1)
671 pset_foreach(vi2->values, irn2)
672 if (values_interfere(lv, irn1, irn2) && arch_get_irn_register(raenv->aenv, irn1) == arch_get_irn_register(raenv->aenv, irn2)) {
673 dump_ir_block_graph_sched(raenv->irg, "ERROR");
674 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);
675 assert(0 && "ERROR graph dumped");
681 /******************************************************************************
685 | |\/| |/ _` | | '_ \
686 | | | | (_| | | | | |
687 |_| |_|\__,_|_|_| |_|
688 *****************************************************************************/
691 * Default values for options
693 static char callee[128] = "\"E:/user/kimohoff/public/register allocator\"";
694 //static char callee[128] = "/ben/kimohoff/ipd-registerallocator/register_allocator";
698 * Allocate registers with an external program using a text-file interface.
700 * Do some computations (SSA-destruction and mapping of values--vars)
702 * Execute external program
703 * Read in results and apply them
706 static void be_ra_extern_main(be_irg_t *birg) {
707 be_main_env_t *env = birg->main_env;
708 ir_graph *irg = birg->irg;
710 be_raext_env_t raenv;
713 be_assure_dom_front(birg);
714 be_assure_liveness(birg);
719 raenv.aenv = env->arch_env;
720 FIRM_DBG_REGISTER(raenv.dbg, "firm.be.raextern");
722 /* Insert copies for constraints */
723 for(clsnr = 0, clss = arch_isa_get_n_reg_class(raenv.aenv->isa); clsnr < clss; ++clsnr) {
724 raenv.cls = arch_isa_get_reg_class(raenv.aenv->isa, clsnr);
725 handle_constraints(&raenv);
728 be_dump(irg, "-extern-constr", dump_ir_block_graph_sched);
730 /* SSA destruction respectively transformation into "Conventional SSA" */
731 raenv.vars = be_ssa_destr_simple(irg, env->arch_env);
732 be_dump(irg, "-extern-ssadestr", dump_ir_block_graph_sched);
735 /* For all register classes */
736 for(clsnr = 0, clss = arch_isa_get_n_reg_class(raenv.aenv->isa); clsnr < clss; ++clsnr) {
738 char out[256], in[256];
740 raenv.cls = arch_isa_get_reg_class(raenv.aenv->isa, clsnr);
742 extract_vars_of_cls(&raenv);
745 ir_snprintf(out, sizeof(out), "%F-%s-%d.ra", irg, raenv.cls->name, round);
746 ir_snprintf(in, sizeof(in), "%F-%s-%d.ra.res", irg, raenv.cls->name, round);
750 dump_to_file(&raenv, out);
751 execute(callee, out, in);
752 done = read_and_apply_results(&raenv, in);
753 be_abi_fix_stack_nodes(birg->abi, birg->lv);
755 ir_snprintf(in, sizeof(in), "-extern-%s-round-%d", raenv.cls->name, round);
756 be_dump(irg, in, dump_ir_block_graph_sched);
761 check_allocation(&raenv);
763 free(raenv.cls_vars);
766 be_dump(irg, "-extern-alloc", dump_ir_block_graph_sched);
769 free_ssa_destr_simple(raenv.vars);
771 be_invalidate_liveness(birg);
774 /******************************************************************************
777 | | | |_ __ | |_ _ ___ _ __ ___
778 | | | | '_ \| __| |/ _ \| '_ \/ __|
779 | |__| | |_) | |_| | (_) | | | \__ \
780 \____/| .__/ \__|_|\___/|_| |_|___/
783 *****************************************************************************/
785 static const lc_opt_enum_func_ptr_items_t ssa_destr_items[] = {
786 { "simple", (int (*)(void)) be_ssa_destr_simple }, /* TODO make (void*) casts nicer */
790 static set* (*ssa_destr)(ir_graph*,const arch_env_t*) = be_ssa_destr_simple;
792 static lc_opt_enum_func_ptr_var_t ssa_destr_var = {
793 (int (**)(void)) &ssa_destr, ssa_destr_items
796 static const lc_opt_table_entry_t be_ra_extern_options[] = {
797 LC_OPT_ENT_ENUM_FUNC_PTR("ssa_destr", "SSA destruction flavor", &ssa_destr_var),
798 LC_OPT_ENT_STR("callee", "The external program to call", callee, sizeof(callee)),
802 static be_ra_t be_ra_external_allocator = {
806 void be_init_raextern(void) {
807 lc_opt_entry_t *be_grp = lc_opt_get_grp(firm_opt_get_root(), "be");
808 lc_opt_entry_t *blocksched_grp = lc_opt_get_grp(be_grp, "ra");
809 lc_opt_entry_t *ext_grp = lc_opt_get_grp(blocksched_grp, "ext");
811 lc_opt_add_table(ext_grp, be_ra_extern_options);
813 be_register_allocator("ext", &be_ra_external_allocator);
815 BE_REGISTER_MODULE_CONSTRUCTOR(be_init_raextern);