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>
78 #include "raw_bitset.h"
80 #include "irprintf_t.h"
82 #include "irgraph_t.h"
84 #include "iredges_t.h"
89 #include "beraextern.h"
94 #include "besched_t.h"
99 #include "bessadestrsimple.h"
104 * Environment with all the needed stuff
106 typedef struct _be_raext_env_t {
108 const arch_register_class_t *cls;
112 FILE *f; /**< file handle used for out- and input file */
113 set *vars; /**< contains all be_var_info_t */
114 int n_cls_vars; /**< length of the array cls_vars */
115 be_var_info_t **cls_vars; /**< only the var_infos for current cls. needed for double iterating */
116 DEBUG_ONLY(firm_dbg_module_t *dbg;)
121 /******************************************************************************
124 | |__| | ___| |_ __ ___ _ __ ___
125 | __ |/ _ \ | '_ \ / _ \ '__/ __|
126 | | | | __/ | |_) | __/ | \__ \
127 |_| |_|\___|_| .__/ \___|_| |___/
130 *****************************************************************************/
133 #define pset_foreach(pset, irn) for(irn=pset_first(pset); irn; irn=pset_next(pset))
134 #define set_foreach(set, e) for(e=set_first(set); e; e=set_next(set))
137 * Checks if _the_ result of the irn belongs to the
138 * current register class (raenv->cls)
139 * NOTE: Only the first result is checked.
141 #define is_res_in_reg_class(irn) arch_irn_has_reg_class(raenv->aenv, irn, -1, raenv->cls)
143 static INLINE ir_node *get_first_non_phi(pset *s) {
152 assert(0 && "There must be a non-phi-irn in this");
156 static INLINE ir_node *get_first_phi(pset *s) {
165 assert(0 && "There must be a phi in this");
169 static int get_loop_weight(ir_node *irn) {
171 ir_loop *loop = get_irn_loop(get_nodes_block(irn));
174 int d = get_loop_depth(loop);
180 #define get_const_weight(irn) (1)
182 #define get_spill_weight(irn) get_loop_weight(irn)
183 #define get_reload_weight(irn) get_loop_weight(irn)
184 #define get_affinity_weight(irn) get_loop_weight(irn)
186 /******************************************************************************
188 / ____| | | / ____| (_)
189 | | ___ _ __ ___| |_ _ __ | | ___ _ __ _ ___ ___
190 | | / _ \| '_ \/ __| __| '__| | | / _ \| '_ \| |/ _ \/ __|
191 | |___| (_) | | | \__ \ |_| | | |___| (_) | |_) | | __/\__ \
192 \_____\___/|_| |_|___/\__|_| \_____\___/| .__/|_|\___||___/
195 *****************************************************************************/
197 static void handle_constraints_insn(be_raext_env_t *env, be_insn_t *insn)
199 ir_node *bl = get_nodes_block(insn->irn);
202 for(i = 0; i < insn->use_start; ++i) {
203 be_operand_t *op = &insn->ops[i];
205 if(op->has_constraints) {
206 ir_node *cpy = be_new_Copy(op->req->cls, env->irg, bl, op->carrier);
207 sched_add_before(insn->next_insn, cpy);
208 edges_reroute(op->carrier, cpy, env->irg);
212 for(i = insn->use_start; i < insn->n_ops; ++i) {
213 be_operand_t *op = &insn->ops[i];
215 if(op->has_constraints) {
216 ir_node *cpy = be_new_Copy(op->req->cls, env->irg, bl, op->carrier);
217 sched_add_before(insn->irn, cpy);
218 set_irn_n(insn->irn, op->pos, cpy);
219 be_set_constr_limited(cpy, BE_OUT_POS(0), op->req);
224 static void handle_constraints_block(ir_node *bl, void *data)
226 be_raext_env_t *raenv = data;
227 int active = bl != get_irg_start_block(raenv->irg);
234 ie.aenv = raenv->aenv;
236 ie.ignore_colors = NULL;
239 irn = sched_first(bl);
240 while(!sched_is_end(irn)) {
241 be_insn_t *insn = be_scan_insn(&ie, irn);
243 if(insn->has_constraints)
244 handle_constraints_insn(raenv, insn);
246 if(be_is_Barrier(irn))
249 irn = insn->next_insn;
250 obstack_free(&obst, insn);
254 static void handle_constraints(be_raext_env_t *raenv) {
255 irg_block_walk_graph(raenv->irg, NULL, handle_constraints_block, raenv);
261 /******************************************************************************
264 | | | |_ _ _ __ ___ _ __ ___ _ __
265 | | | | | | | '_ ` _ \| '_ \ / _ \ '__|
266 | |__| | |_| | | | | | | |_) | __/ |
267 |_____/ \__,_|_| |_| |_| .__/ \___|_|
270 *****************************************************************************/
273 static void extract_vars_of_cls(be_raext_env_t *raenv) {
277 raenv->cls_vars = xmalloc(set_count(raenv->vars) * sizeof(*raenv->cls_vars));
278 assert(raenv->cls_vars);
280 set_foreach(raenv->vars, vi)
281 if (is_res_in_reg_class(get_first_non_phi(vi->values)))
282 raenv->cls_vars[count++] = vi;
284 raenv->cls_vars = realloc(raenv->cls_vars, count * sizeof(*raenv->cls_vars));
285 assert(raenv->cls_vars);
287 raenv->n_cls_vars = count;
292 * Check if node irn has a limited-constraint at position pos.
293 * If yes, dump it to FILE raenv->f
295 static INLINE void dump_constraint(be_raext_env_t *raenv, ir_node *irn, int pos) {
296 const arch_register_req_t *req;
298 req = arch_get_register_req(raenv->aenv, irn, pos);
299 if (arch_register_req_is(req, limited)) {
302 reg_nr = rbitset_next(req->limited, 0, 1);
303 fprintf(raenv->f, "<%d>", reg_nr);
304 assert(rbitset_popcnt(req->limited, raenv->cls->n_regs) <= 1
305 && "Constraints with more than 1 possible register are not supported");
309 #define UNSPILLABLE -1
311 static INLINE int get_spill_costs(be_raext_env_t *raenv, be_var_info_t *vi) {
313 int c_spills=0, c_reloads=0;
315 pset_foreach(vi->values, irn) {
316 if (arch_irn_is(raenv->aenv, irn, ignore) || be_is_Reload(irn)) {
317 pset_break(vi->values);
322 /* number of reloads is the number of non-phi uses of all values of this var */
323 const ir_edge_t *edge;
324 foreach_out_edge(irn, edge)
325 if (!is_Phi(edge->src))
326 c_reloads += get_reload_weight(edge->src);
328 /* number of spills is the number of non-phi values for this var */
329 c_spills += get_spill_weight(irn);
333 return c_spills + c_reloads;
336 static void dump_nodes(be_raext_env_t *raenv) {
340 fprintf(f, "\nnodes {\n");
342 for (i=0; i<raenv->n_cls_vars; ++i) {
343 be_var_info_t *vi = raenv->cls_vars[i];
345 if (vi->var_nr == SET_REMOVED)
348 fprintf(f, "%d %d", vi->var_nr, get_spill_costs(raenv, vi));
349 dump_constraint(raenv, get_first_non_phi(vi->values), -1);
358 static void dump_interferences(be_raext_env_t *raenv) {
360 be_var_info_t *vi1, *vi2;
361 ir_node *irn1, *irn2;
363 be_lv_t *lv = raenv->birg->lv;
365 fprintf(f, "\ninterferences {\n");
367 for (i=0; i<raenv->n_cls_vars; ++i) {
368 vi1 = raenv->cls_vars[i];
370 if (vi1->var_nr == SET_REMOVED)
373 for (o=i+1; o<raenv->n_cls_vars; ++o) {
374 vi2 = raenv->cls_vars[o];
376 if (vi2->var_nr == SET_REMOVED)
379 pset_foreach(vi1->values, irn1)
380 pset_foreach(vi2->values, irn2)
381 if (values_interfere(lv, irn1, irn2)) {
382 pset_break(vi1->values);
383 pset_break(vi2->values);
384 fprintf(f, "(%d, %d)\n", vi1->var_nr, vi2->var_nr);
394 static void dump_affinities_walker(ir_node *irn, void *env) {
395 be_raext_env_t *raenv = env;
396 const arch_register_req_t *req;
398 be_var_info_t *vi1, *vi2;
400 if (arch_get_irn_reg_class(raenv->aenv, irn, -1) != raenv->cls || arch_irn_is(raenv->aenv, irn, ignore))
403 vi1 = be_get_var_info(irn);
405 /* copies have affinities */
406 if (arch_irn_class_is(raenv->aenv, irn, copy)) {
407 ir_node *other = be_get_Copy_op(irn);
409 if (! arch_irn_is(raenv->aenv, other, ignore)) {
410 vi2 = be_get_var_info(other);
412 fprintf(raenv->f, "(%d, %d, %d)\n", vi1->var_nr, vi2->var_nr, get_affinity_weight(irn));
417 /* should_be_equal constraints are affinites */
418 for (pos = 0, max = get_irn_arity(irn); pos<max; ++pos) {
419 req = arch_get_register_req(raenv->aenv, irn, pos);
421 if (arch_register_req_is(req, should_be_same)) {
422 ir_node *other = get_irn_n(irn, req->other_same);
423 if(arch_irn_is(raenv->aenv, other, ignore)) {
424 vi2 = be_get_var_info(other);
426 fprintf(raenv->f, "(%d, %d, %d)\n", vi1->var_nr, vi2->var_nr, get_affinity_weight(irn));
433 static void dump_affinities(be_raext_env_t *raenv) {
434 fprintf(raenv->f, "\naffinities {\n");
435 irg_walk_graph(raenv->irg, NULL, dump_affinities_walker, raenv);
436 fprintf(raenv->f, "}\n");
440 * Dump all information needed by the external
441 * register allocator to a single file.
443 static void dump_to_file(be_raext_env_t *raenv, char *filename) {
446 if (!(f = fopen(filename, "wt"))) {
447 fprintf(stderr, "Could not open file %s for writing\n", filename);
453 /* dump register info */
454 fprintf(f, "regs %d\n", arch_register_class_n_regs(raenv->cls));
456 /* dump the interference graph */
458 dump_interferences(raenv);
459 dump_affinities(raenv);
464 /******************************************************************************
467 | |__ __ _____ ___ _ _| |_ ___
468 | __| \ \/ / _ \/ __| | | | __/ _ \
469 | |____ > < __/ (__| |_| | || __/
470 |______/_/\_\___|\___|\__,_|\__\___|
471 *****************************************************************************/
474 * Execute the external register allocator specified in the
475 * firm-option firm.be.ra.ext.callee
477 static void execute(char *prog_to_call, char *out_file, char *result_file) {
481 snprintf(cmd_line, sizeof(cmd_line), "%s -i %s -o %s", prog_to_call, out_file, result_file);
482 cmd_line[sizeof(cmd_line) - 1] = '\0';
484 ret_status = system(cmd_line);
485 assert(ret_status != -1 && "Invokation of external register allocator failed");
486 assert(ret_status == 0 && "External register allocator is unhappy with sth.");
489 /******************************************************************************
492 / \ _ __ _ __ | |_ _ | |__) |___ ___ _ _| | |_
493 / /\ \ | '_ \| '_ \| | | | | | _ // _ \/ __| | | | | __|
494 / ____ \| |_) | |_) | | |_| | | | \ \ __/\__ \ |_| | | |_
495 /_/ \_\ .__/| .__/|_|\__, | |_| \_\___||___/\__,_|_|\__|
498 *****************************************************************************/
501 * Spill a variable and add reloads before all uses.
503 static INLINE void var_add_spills_and_reloads(be_raext_env_t *raenv, int var_nr) {
504 be_var_info_t *vi = be_var_find(raenv->vars, var_nr);
505 ir_node *spill=NULL, *ctx, *irn;
507 const ir_edge_t *edge, *ne;
508 pset *spills = pset_new_ptr(4); /* the spills of this variable */
509 pset *reloads = pset_new_ptr(4); /* the reloads of this variable */
510 be_lv_t *lv = raenv->birg->lv;
511 be_dom_front_info_t *dom_front = raenv->birg->dom_front;
512 int new_size, n_spills, n_reloads;
514 assert(vi && "Variable nr does not exist!");
515 assert(pset_count(vi->values) && "There are no values associated to this variable");
517 /* the spill context is set to an arbitrary node of the phi-class,
518 * or the node itself if it is not member of a phi class
520 if (pset_count(vi->values) == 1)
521 ctx = get_first_non_phi(vi->values);
523 ctx = get_first_phi(vi->values);
525 DBG((raenv->dbg, LEVEL_2, "Spill context: %+F\n", ctx));
527 /* for each value of this variable insert the spills */
528 pset_foreach(vi->values, irn) {
534 /* all ordinary nodes must be spilled */
535 DBG((raenv->dbg, LEVEL_2, " spilling %+F\n", irn));
536 spill = be_spill(raenv->aenv, irn);
538 /* remember the spill */
539 pset_insert_ptr(spills, spill);
542 assert(spill && "There must be at least one non-phi-node");
544 mode = get_irn_mode(get_irn_n(spill, be_pos_Spill_val));
546 /* insert reloads and wire them arbitrary*/
547 pset_foreach(vi->values, irn)
548 foreach_out_edge_safe(irn, edge, ne) {
549 ir_node *reload, *src = edge->src;
550 if (is_Phi(src) || be_is_Spill(src))
553 /* all real uses must be reloaded */
554 DBG((raenv->dbg, LEVEL_2, " reloading before %+F\n", src));
555 reload = be_reload(raenv->aenv, raenv->cls, edge->src, mode, spill);
556 set_irn_n(edge->src, edge->pos, reload);
558 /* remember the reload */
559 pset_insert_ptr(reloads, reload);
562 /* correct the reload->spill pointers... */
563 be_ssa_constr_set(dom_front, lv, spills);
566 /****** correct the variable <--> values mapping: ******
568 * - if we had a phi class it gets split into several new variables
569 * - all reloads are new variables
571 n_spills = pset_count(spills);
572 n_reloads = pset_count(reloads);
574 /* first make room for new pointers in the cls_var array */
575 new_size = raenv->n_cls_vars + n_reloads + ((n_spills>1) ? n_spills : 0);
576 raenv->cls_vars = realloc(raenv->cls_vars, (new_size) * sizeof(*raenv->cls_vars));
577 assert(raenv->cls_vars && "Out of mem!?");
579 /* if we had a real phi-class, we must... */
580 if (pset_count(spills) > 1) {
581 /* ...remove the old variable corresponding to the phi class */
582 vi->var_nr = SET_REMOVED;
584 /* ...add new vars for each non-phi-member */
585 pset_foreach(spills, irn) {
586 ir_node *spilled = get_irn_n(irn, be_pos_Spill_val);
587 raenv->cls_vars[raenv->n_cls_vars++] = be_var_add_value(raenv->vars, get_irn_node_nr(spilled), spilled);
591 /* add new variables for all reloads */
592 pset_foreach(reloads, irn) {
593 assert(get_irn_node_nr(irn) != 1089);
594 raenv->cls_vars[raenv->n_cls_vars++] = be_var_add_value(raenv->vars, get_irn_node_nr(irn), irn);
601 #define INVALID_FILE_FORMAT assert(0 && "Invalid file format.")
603 #define BUFCONV " %32s "
606 * Read in the actions performed by the external allocator.
607 * Apply these transformations to the irg.
608 * @return 1 if an allocation was read in. 0 otherwise.
610 static int read_and_apply_results(be_raext_env_t *raenv, char *filename) {
613 int is_allocation = 0;
615 if (!(f = fopen(filename, "rt"))) {
616 fprintf(stderr, "Could not open file %s for reading\n", filename);
622 /* read the action */
623 if (fscanf(f, BUFCONV, buf) != 1)
627 if (!strcmp(buf, "spills")) {
629 while (fscanf(f, " %d ", &var_nr) == 1)
630 var_add_spills_and_reloads(raenv, var_nr);
633 /* or do we allocate */
634 if (!strcmp(buf, "allocs")) {
638 while (fscanf(f, " %d %d ", &var_nr, ®_nr) == 2) {
640 pset *vals = be_get_var_values(raenv->vars, var_nr);
642 assert(vals && "Variable nr does not exist!");
643 pset_foreach(vals, irn)
644 arch_set_irn_register(raenv->aenv, irn, arch_register_for_index(raenv->cls, reg_nr));
654 return is_allocation;
657 static void check_allocation(be_raext_env_t *raenv) {
659 be_lv_t *lv = raenv->birg->lv;
661 for (i=0; i<raenv->n_cls_vars; ++i) {
662 be_var_info_t *vi1 = raenv->cls_vars[i];
664 if (vi1->var_nr == SET_REMOVED)
667 for (o=0; o<i; ++o) {
668 be_var_info_t *vi2 = raenv->cls_vars[o];
669 ir_node *irn1, *irn2;
671 if (vi2->var_nr == SET_REMOVED)
674 pset_foreach(vi1->values, irn1)
675 pset_foreach(vi2->values, irn2)
676 if (values_interfere(lv, irn1, irn2) && arch_get_irn_register(raenv->aenv, irn1) == arch_get_irn_register(raenv->aenv, irn2)) {
677 dump_ir_block_graph_sched(raenv->irg, "ERROR");
678 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);
679 assert(0 && "ERROR graph dumped");
685 /******************************************************************************
689 | |\/| |/ _` | | '_ \
690 | | | | (_| | | | | |
691 |_| |_|\__,_|_|_| |_|
692 *****************************************************************************/
695 * Default values for options
697 static char callee[128] = "\"E:/user/kimohoff/public/register allocator\"";
698 //static char callee[128] = "/ben/kimohoff/ipd-registerallocator/register_allocator";
702 * Allocate registers with an external program using a text-file interface.
704 * Do some computations (SSA-destruction and mapping of values--vars)
706 * Execute external program
707 * Read in results and apply them
710 static void be_ra_extern_main(be_irg_t *birg) {
711 be_main_env_t *env = birg->main_env;
712 ir_graph *irg = birg->irg;
714 be_raext_env_t raenv;
717 be_assure_dom_front(birg);
718 be_assure_liveness(birg);
723 raenv.aenv = env->arch_env;
724 FIRM_DBG_REGISTER(raenv.dbg, "firm.be.raextern");
726 /* Insert copies for constraints */
727 for(clsnr = 0, clss = arch_isa_get_n_reg_class(raenv.aenv->isa); clsnr < clss; ++clsnr) {
728 raenv.cls = arch_isa_get_reg_class(raenv.aenv->isa, clsnr);
729 handle_constraints(&raenv);
732 be_dump(irg, "-extern-constr", dump_ir_block_graph_sched);
734 /* SSA destruction respectively transformation into "Conventional SSA" */
735 raenv.vars = be_ssa_destr_simple(irg, env->arch_env);
736 be_dump(irg, "-extern-ssadestr", dump_ir_block_graph_sched);
739 /* For all register classes */
740 for(clsnr = 0, clss = arch_isa_get_n_reg_class(raenv.aenv->isa); clsnr < clss; ++clsnr) {
742 char out[256], in[256];
744 raenv.cls = arch_isa_get_reg_class(raenv.aenv->isa, clsnr);
746 extract_vars_of_cls(&raenv);
749 ir_snprintf(out, sizeof(out), "%F-%s-%d.ra", irg, raenv.cls->name, round);
750 ir_snprintf(in, sizeof(in), "%F-%s-%d.ra.res", irg, raenv.cls->name, round);
754 dump_to_file(&raenv, out);
755 execute(callee, out, in);
756 done = read_and_apply_results(&raenv, in);
757 be_abi_fix_stack_nodes(birg->abi, birg->lv);
759 ir_snprintf(in, sizeof(in), "-extern-%s-round-%d", raenv.cls->name, round);
760 be_dump(irg, in, dump_ir_block_graph_sched);
765 check_allocation(&raenv);
767 free(raenv.cls_vars);
770 be_dump(irg, "-extern-alloc", dump_ir_block_graph_sched);
773 free_ssa_destr_simple(raenv.vars);
775 be_invalidate_liveness(birg);
778 /******************************************************************************
781 | | | |_ __ | |_ _ ___ _ __ ___
782 | | | | '_ \| __| |/ _ \| '_ \/ __|
783 | |__| | |_) | |_| | (_) | | | \__ \
784 \____/| .__/ \__|_|\___/|_| |_|___/
787 *****************************************************************************/
789 static const lc_opt_enum_func_ptr_items_t ssa_destr_items[] = {
790 { "simple", (int (*)(void)) be_ssa_destr_simple }, /* TODO make (void*) casts nicer */
794 static set* (*ssa_destr)(ir_graph*,const arch_env_t*) = be_ssa_destr_simple;
796 static lc_opt_enum_func_ptr_var_t ssa_destr_var = {
797 (int (**)(void)) &ssa_destr, ssa_destr_items
800 static const lc_opt_table_entry_t be_ra_extern_options[] = {
801 LC_OPT_ENT_ENUM_FUNC_PTR("ssa_destr", "SSA destruction flavor", &ssa_destr_var),
802 LC_OPT_ENT_STR("callee", "The external program to call", callee, sizeof(callee)),
806 static be_ra_t be_ra_external_allocator = {
810 void be_init_raextern(void) {
811 lc_opt_entry_t *be_grp = lc_opt_get_grp(firm_opt_get_root(), "be");
812 lc_opt_entry_t *blocksched_grp = lc_opt_get_grp(be_grp, "ra");
813 lc_opt_entry_t *ext_grp = lc_opt_get_grp(blocksched_grp, "ext");
815 lc_opt_add_table(ext_grp, be_ra_extern_options);
817 be_register_allocator("ext", &be_ra_external_allocator);
819 BE_REGISTER_MODULE_CONSTRUCTOR(be_init_raextern);