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 ********/
64 #include <libcore/lc_opts.h>
65 #include <libcore/lc_opts_enum.h>
71 #include "raw_bitset.h"
74 #include "irprintf_t.h"
76 #include "irgraph_t.h"
78 #include "iredges_t.h"
83 #include "beraextern.h"
88 #include "besched_t.h"
93 #include "bessadestrsimple.h"
98 * Environment with all the needed stuff
100 typedef struct _be_raext_env_t {
102 const arch_register_class_t *cls;
106 FILE *f; /**< file handle used for out- and input file */
107 set *vars; /**< contains all be_var_info_t */
108 int n_cls_vars; /**< length of the array cls_vars */
109 be_var_info_t **cls_vars; /**< only the var_infos for current cls. needed for double iterating */
110 DEBUG_ONLY(firm_dbg_module_t *dbg;)
115 /******************************************************************************
118 | |__| | ___| |_ __ ___ _ __ ___
119 | __ |/ _ \ | '_ \ / _ \ '__/ __|
120 | | | | __/ | |_) | __/ | \__ \
121 |_| |_|\___|_| .__/ \___|_| |___/
124 *****************************************************************************/
127 #define pset_foreach(pset, irn) for(irn=pset_first(pset); irn; irn=pset_next(pset))
128 #define set_foreach(set, e) for(e=set_first(set); e; e=set_next(set))
131 * Checks if _the_ result of the irn belongs to the
132 * current register class (raenv->cls)
133 * NOTE: Only the first result is checked.
135 #define is_res_in_reg_class(irn) arch_irn_has_reg_class(raenv->aenv, irn, -1, raenv->cls)
137 static INLINE ir_node *get_first_non_phi(pset *s) {
146 assert(0 && "There must be a non-phi-irn in this");
150 static INLINE ir_node *get_first_phi(pset *s) {
159 assert(0 && "There must be a phi in this");
163 static int get_loop_weight(ir_node *irn) {
165 ir_loop *loop = get_irn_loop(get_nodes_block(irn));
168 int d = get_loop_depth(loop);
174 #define get_const_weight(irn) (1)
176 #define get_spill_weight(irn) get_loop_weight(irn)
177 #define get_reload_weight(irn) get_loop_weight(irn)
178 #define get_affinity_weight(irn) get_loop_weight(irn)
180 /******************************************************************************
182 / ____| | | / ____| (_)
183 | | ___ _ __ ___| |_ _ __ | | ___ _ __ _ ___ ___
184 | | / _ \| '_ \/ __| __| '__| | | / _ \| '_ \| |/ _ \/ __|
185 | |___| (_) | | | \__ \ |_| | | |___| (_) | |_) | | __/\__ \
186 \_____\___/|_| |_|___/\__|_| \_____\___/| .__/|_|\___||___/
189 *****************************************************************************/
191 static void handle_constraints_insn(be_raext_env_t *env, be_insn_t *insn)
193 ir_node *bl = get_nodes_block(insn->irn);
196 for(i = 0; i < insn->use_start; ++i) {
197 be_operand_t *op = &insn->ops[i];
199 if(op->has_constraints) {
200 ir_node *cpy = be_new_Copy(op->req->cls, env->irg, bl, op->carrier);
201 sched_add_before(insn->next_insn, cpy);
202 edges_reroute(op->carrier, cpy, env->irg);
206 for(i = insn->use_start; i < insn->n_ops; ++i) {
207 be_operand_t *op = &insn->ops[i];
209 if(op->has_constraints) {
210 ir_node *cpy = be_new_Copy(op->req->cls, env->irg, bl, op->carrier);
211 sched_add_before(insn->irn, cpy);
212 set_irn_n(insn->irn, op->pos, cpy);
213 be_set_constr_limited(cpy, BE_OUT_POS(0), op->req);
218 static void handle_constraints_block(ir_node *bl, void *data)
220 be_raext_env_t *raenv = data;
221 int active = bl != get_irg_start_block(raenv->irg);
228 ie.aenv = raenv->aenv;
230 ie.ignore_colors = NULL;
233 irn = sched_first(bl);
234 while(!sched_is_end(irn)) {
235 be_insn_t *insn = be_scan_insn(&ie, irn);
237 if(insn->has_constraints)
238 handle_constraints_insn(raenv, insn);
240 if(be_is_Barrier(irn))
243 irn = insn->next_insn;
244 obstack_free(&obst, insn);
248 static void handle_constraints(be_raext_env_t *raenv) {
249 irg_block_walk_graph(raenv->irg, NULL, handle_constraints_block, raenv);
255 /******************************************************************************
258 | | | |_ _ _ __ ___ _ __ ___ _ __
259 | | | | | | | '_ ` _ \| '_ \ / _ \ '__|
260 | |__| | |_| | | | | | | |_) | __/ |
261 |_____/ \__,_|_| |_| |_| .__/ \___|_|
264 *****************************************************************************/
267 static void extract_vars_of_cls(be_raext_env_t *raenv) {
271 raenv->cls_vars = xmalloc(set_count(raenv->vars) * sizeof(*raenv->cls_vars));
272 assert(raenv->cls_vars);
274 set_foreach(raenv->vars, vi)
275 if (is_res_in_reg_class(get_first_non_phi(vi->values)))
276 raenv->cls_vars[count++] = vi;
278 raenv->cls_vars = realloc(raenv->cls_vars, count * sizeof(*raenv->cls_vars));
279 assert(raenv->cls_vars);
281 raenv->n_cls_vars = count;
286 * Check if node irn has a limited-constraint at position pos.
287 * If yes, dump it to FILE raenv->f
289 static INLINE void dump_constraint(be_raext_env_t *raenv, ir_node *irn, int pos) {
290 const arch_register_req_t *req;
292 req = arch_get_register_req(raenv->aenv, irn, pos);
293 if (arch_register_req_is(req, limited)) {
296 reg_nr = rbitset_next(req->limited, 0, 1);
297 fprintf(raenv->f, "<%d>", reg_nr);
298 assert(rbitset_popcnt(req->limited, raenv->cls->n_regs) <= 1
299 && "Constraints with more than 1 possible register are not supported");
303 #define UNSPILLABLE -1
305 static INLINE int get_spill_costs(be_raext_env_t *raenv, be_var_info_t *vi) {
307 int c_spills=0, c_reloads=0;
309 pset_foreach(vi->values, irn) {
310 if (arch_irn_is(raenv->aenv, irn, ignore) || be_is_Reload(irn)) {
311 pset_break(vi->values);
316 /* number of reloads is the number of non-phi uses of all values of this var */
317 const ir_edge_t *edge;
318 foreach_out_edge(irn, edge)
319 if (!is_Phi(edge->src))
320 c_reloads += get_reload_weight(edge->src);
322 /* number of spills is the number of non-phi values for this var */
323 c_spills += get_spill_weight(irn);
327 return c_spills + c_reloads;
330 static void dump_nodes(be_raext_env_t *raenv) {
334 fprintf(f, "\nnodes {\n");
336 for (i=0; i<raenv->n_cls_vars; ++i) {
337 be_var_info_t *vi = raenv->cls_vars[i];
339 if (vi->var_nr == SET_REMOVED)
342 fprintf(f, "%d %d", vi->var_nr, get_spill_costs(raenv, vi));
343 dump_constraint(raenv, get_first_non_phi(vi->values), -1);
352 static void dump_interferences(be_raext_env_t *raenv) {
354 be_var_info_t *vi1, *vi2;
355 ir_node *irn1, *irn2;
357 be_lv_t *lv = raenv->birg->lv;
359 fprintf(f, "\ninterferences {\n");
361 for (i=0; i<raenv->n_cls_vars; ++i) {
362 vi1 = raenv->cls_vars[i];
364 if (vi1->var_nr == SET_REMOVED)
367 for (o=i+1; o<raenv->n_cls_vars; ++o) {
368 vi2 = raenv->cls_vars[o];
370 if (vi2->var_nr == SET_REMOVED)
373 pset_foreach(vi1->values, irn1)
374 pset_foreach(vi2->values, irn2)
375 if (values_interfere(lv, irn1, irn2)) {
376 pset_break(vi1->values);
377 pset_break(vi2->values);
378 fprintf(f, "(%d, %d)\n", vi1->var_nr, vi2->var_nr);
388 static void dump_affinities_walker(ir_node *irn, void *env) {
389 be_raext_env_t *raenv = env;
390 const arch_register_req_t *req;
392 be_var_info_t *vi1, *vi2;
394 if (arch_get_irn_reg_class(raenv->aenv, irn, -1) != raenv->cls || arch_irn_is(raenv->aenv, irn, ignore))
397 vi1 = be_get_var_info(irn);
399 /* copies have affinities */
400 if (arch_irn_class_is(raenv->aenv, irn, copy)) {
401 ir_node *other = be_get_Copy_op(irn);
403 if (! arch_irn_is(raenv->aenv, other, ignore)) {
404 vi2 = be_get_var_info(other);
406 fprintf(raenv->f, "(%d, %d, %d)\n", vi1->var_nr, vi2->var_nr, get_affinity_weight(irn));
411 /* should_be_equal constraints are affinites */
412 for (pos = 0, max = get_irn_arity(irn); pos<max; ++pos) {
413 req = arch_get_register_req(raenv->aenv, irn, pos);
415 if (arch_register_req_is(req, should_be_same)) {
416 ir_node *other = get_irn_n(irn, req->other_same);
417 if(arch_irn_is(raenv->aenv, other, ignore)) {
418 vi2 = be_get_var_info(other);
420 fprintf(raenv->f, "(%d, %d, %d)\n", vi1->var_nr, vi2->var_nr, get_affinity_weight(irn));
427 static void dump_affinities(be_raext_env_t *raenv) {
428 fprintf(raenv->f, "\naffinities {\n");
429 irg_walk_graph(raenv->irg, NULL, dump_affinities_walker, raenv);
430 fprintf(raenv->f, "}\n");
434 * Dump all information needed by the external
435 * register allocator to a single file.
437 static void dump_to_file(be_raext_env_t *raenv, char *filename) {
440 if (!(f = fopen(filename, "wt"))) {
441 fprintf(stderr, "Could not open file %s for writing\n", filename);
447 /* dump register info */
448 fprintf(f, "regs %d\n", arch_register_class_n_regs(raenv->cls));
450 /* dump the interference graph */
452 dump_interferences(raenv);
453 dump_affinities(raenv);
458 /******************************************************************************
461 | |__ __ _____ ___ _ _| |_ ___
462 | __| \ \/ / _ \/ __| | | | __/ _ \
463 | |____ > < __/ (__| |_| | || __/
464 |______/_/\_\___|\___|\__,_|\__\___|
465 *****************************************************************************/
468 * Execute the external register allocator specified in the
469 * firm-option firm.be.ra.ext.callee
471 static void execute(char *prog_to_call, char *out_file, char *result_file) {
475 snprintf(cmd_line, sizeof(cmd_line), "%s -i %s -o %s", prog_to_call, out_file, result_file);
476 cmd_line[sizeof(cmd_line) - 1] = '\0';
478 ret_status = system(cmd_line);
479 assert(ret_status != -1 && "Invokation of external register allocator failed");
480 assert(ret_status == 0 && "External register allocator is unhappy with sth.");
483 /******************************************************************************
486 / \ _ __ _ __ | |_ _ | |__) |___ ___ _ _| | |_
487 / /\ \ | '_ \| '_ \| | | | | | _ // _ \/ __| | | | | __|
488 / ____ \| |_) | |_) | | |_| | | | \ \ __/\__ \ |_| | | |_
489 /_/ \_\ .__/| .__/|_|\__, | |_| \_\___||___/\__,_|_|\__|
492 *****************************************************************************/
495 * Spill a variable and add reloads before all uses.
497 static INLINE void var_add_spills_and_reloads(be_raext_env_t *raenv, int var_nr) {
498 be_var_info_t *vi = be_var_find(raenv->vars, var_nr);
499 ir_node *spill=NULL, *ctx, *irn;
501 const ir_edge_t *edge, *ne;
502 pset *spills = pset_new_ptr(4); /* the spills of this variable */
503 pset *reloads = pset_new_ptr(4); /* the reloads of this variable */
504 be_lv_t *lv = raenv->birg->lv;
505 be_dom_front_info_t *dom_front = raenv->birg->dom_front;
506 int new_size, n_spills, n_reloads;
508 assert(vi && "Variable nr does not exist!");
509 assert(pset_count(vi->values) && "There are no values associated to this variable");
511 /* the spill context is set to an arbitrary node of the phi-class,
512 * or the node itself if it is not member of a phi class
514 if (pset_count(vi->values) == 1)
515 ctx = get_first_non_phi(vi->values);
517 ctx = get_first_phi(vi->values);
519 DBG((raenv->dbg, LEVEL_2, "Spill context: %+F\n", ctx));
521 /* for each value of this variable insert the spills */
522 pset_foreach(vi->values, irn) {
528 /* all ordinary nodes must be spilled */
529 DBG((raenv->dbg, LEVEL_2, " spilling %+F\n", irn));
530 spill = be_spill(raenv->aenv, irn);
532 /* remember the spill */
533 pset_insert_ptr(spills, spill);
536 assert(spill && "There must be at least one non-phi-node");
538 mode = get_irn_mode(get_irn_n(spill, be_pos_Spill_val));
540 /* insert reloads and wire them arbitrary*/
541 pset_foreach(vi->values, irn) {
542 foreach_out_edge_safe(irn, edge, ne) {
543 ir_node *reload, *src = edge->src;
544 if (is_Phi(src) || be_is_Spill(src))
547 /* all real uses must be reloaded */
548 DBG((raenv->dbg, LEVEL_2, " reloading before %+F\n", src));
549 reload = be_reload(raenv->aenv, raenv->cls, edge->src, mode, spill);
550 set_irn_n(edge->src, edge->pos, reload);
552 /* remember the reload */
553 pset_insert_ptr(reloads, reload);
557 /* correct the reload->spill pointers... */
558 be_ssa_constr_set_ignore(dom_front, lv, spills, NULL);
561 /****** correct the variable <--> values mapping: ******
563 * - if we had a phi class it gets split into several new variables
564 * - all reloads are new variables
566 n_spills = pset_count(spills);
567 n_reloads = pset_count(reloads);
569 /* first make room for new pointers in the cls_var array */
570 new_size = raenv->n_cls_vars + n_reloads + ((n_spills>1) ? n_spills : 0);
571 raenv->cls_vars = realloc(raenv->cls_vars, (new_size) * sizeof(*raenv->cls_vars));
572 assert(raenv->cls_vars && "Out of mem!?");
574 /* if we had a real phi-class, we must... */
575 if (pset_count(spills) > 1) {
576 /* ...remove the old variable corresponding to the phi class */
577 vi->var_nr = SET_REMOVED;
579 /* ...add new vars for each non-phi-member */
580 pset_foreach(spills, irn) {
581 ir_node *spilled = get_irn_n(irn, be_pos_Spill_val);
582 raenv->cls_vars[raenv->n_cls_vars++] = be_var_add_value(raenv->vars, get_irn_node_nr(spilled), spilled);
586 /* add new variables for all reloads */
587 pset_foreach(reloads, irn) {
588 assert(get_irn_node_nr(irn) != 1089);
589 raenv->cls_vars[raenv->n_cls_vars++] = be_var_add_value(raenv->vars, get_irn_node_nr(irn), irn);
596 #define INVALID_FILE_FORMAT assert(0 && "Invalid file format.")
598 #define BUFCONV " %32s "
601 * Read in the actions performed by the external allocator.
602 * Apply these transformations to the irg.
603 * @return 1 if an allocation was read in. 0 otherwise.
605 static int read_and_apply_results(be_raext_env_t *raenv, char *filename) {
608 int is_allocation = 0;
610 if (!(f = fopen(filename, "rt"))) {
611 fprintf(stderr, "Could not open file %s for reading\n", filename);
617 /* read the action */
618 if (fscanf(f, BUFCONV, buf) != 1)
622 if (!strcmp(buf, "spills")) {
624 while (fscanf(f, " %d ", &var_nr) == 1)
625 var_add_spills_and_reloads(raenv, var_nr);
628 /* or do we allocate */
629 if (!strcmp(buf, "allocs")) {
633 while (fscanf(f, " %d %d ", &var_nr, ®_nr) == 2) {
635 pset *vals = be_get_var_values(raenv->vars, var_nr);
637 assert(vals && "Variable nr does not exist!");
638 pset_foreach(vals, irn)
639 arch_set_irn_register(raenv->aenv, irn, arch_register_for_index(raenv->cls, reg_nr));
649 return is_allocation;
652 static void check_allocation(be_raext_env_t *raenv) {
654 be_lv_t *lv = raenv->birg->lv;
656 for (i=0; i<raenv->n_cls_vars; ++i) {
657 be_var_info_t *vi1 = raenv->cls_vars[i];
659 if (vi1->var_nr == SET_REMOVED)
662 for (o=0; o<i; ++o) {
663 be_var_info_t *vi2 = raenv->cls_vars[o];
664 ir_node *irn1, *irn2;
666 if (vi2->var_nr == SET_REMOVED)
669 pset_foreach(vi1->values, irn1)
670 pset_foreach(vi2->values, irn2)
671 if (values_interfere(lv, irn1, irn2) && arch_get_irn_register(raenv->aenv, irn1) == arch_get_irn_register(raenv->aenv, irn2)) {
672 dump_ir_block_graph_sched(raenv->irg, "ERROR");
673 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);
674 assert(0 && "ERROR graph dumped");
680 /******************************************************************************
684 | |\/| |/ _` | | '_ \
685 | | | | (_| | | | | |
686 |_| |_|\__,_|_|_| |_|
687 *****************************************************************************/
690 * Default values for options
692 static char callee[128] = "\"E:/user/kimohoff/public/register allocator\"";
693 //static char callee[128] = "/ben/kimohoff/ipd-registerallocator/register_allocator";
697 * Allocate registers with an external program using a text-file interface.
699 * Do some computations (SSA-destruction and mapping of values--vars)
701 * Execute external program
702 * Read in results and apply them
705 static void be_ra_extern_main(be_irg_t *birg) {
706 be_main_env_t *env = birg->main_env;
707 ir_graph *irg = birg->irg;
709 be_raext_env_t raenv;
712 be_assure_dom_front(birg);
713 be_assure_liveness(birg);
718 raenv.aenv = env->arch_env;
719 FIRM_DBG_REGISTER(raenv.dbg, "firm.be.raextern");
721 /* Insert copies for constraints */
722 for(clsnr = 0, clss = arch_isa_get_n_reg_class(raenv.aenv->isa); clsnr < clss; ++clsnr) {
723 raenv.cls = arch_isa_get_reg_class(raenv.aenv->isa, clsnr);
724 handle_constraints(&raenv);
727 be_dump(irg, "-extern-constr", dump_ir_block_graph_sched);
729 /* SSA destruction respectively transformation into "Conventional SSA" */
730 raenv.vars = be_ssa_destr_simple(irg, env->arch_env);
731 be_dump(irg, "-extern-ssadestr", dump_ir_block_graph_sched);
734 /* For all register classes */
735 for(clsnr = 0, clss = arch_isa_get_n_reg_class(raenv.aenv->isa); clsnr < clss; ++clsnr) {
737 char out[256], in[256];
739 raenv.cls = arch_isa_get_reg_class(raenv.aenv->isa, clsnr);
741 extract_vars_of_cls(&raenv);
744 ir_snprintf(out, sizeof(out), "%F-%s-%d.ra", irg, raenv.cls->name, round);
745 ir_snprintf(in, sizeof(in), "%F-%s-%d.ra.res", irg, raenv.cls->name, round);
749 dump_to_file(&raenv, out);
750 execute(callee, out, in);
751 done = read_and_apply_results(&raenv, in);
752 be_abi_fix_stack_nodes(birg->abi);
754 ir_snprintf(in, sizeof(in), "-extern-%s-round-%d", raenv.cls->name, round);
755 be_dump(irg, in, dump_ir_block_graph_sched);
760 check_allocation(&raenv);
762 free(raenv.cls_vars);
765 be_dump(irg, "-extern-alloc", dump_ir_block_graph_sched);
768 free_ssa_destr_simple(raenv.vars);
770 be_invalidate_liveness(birg);
773 /******************************************************************************
776 | | | |_ __ | |_ _ ___ _ __ ___
777 | | | | '_ \| __| |/ _ \| '_ \/ __|
778 | |__| | |_) | |_| | (_) | | | \__ \
779 \____/| .__/ \__|_|\___/|_| |_|___/
782 *****************************************************************************/
784 static const lc_opt_enum_func_ptr_items_t ssa_destr_items[] = {
785 { "simple", (int (*)(void)) be_ssa_destr_simple }, /* TODO make (void*) casts nicer */
789 static set* (*ssa_destr)(ir_graph*,const arch_env_t*) = be_ssa_destr_simple;
791 static lc_opt_enum_func_ptr_var_t ssa_destr_var = {
792 (int (**)(void)) &ssa_destr, ssa_destr_items
795 static const lc_opt_table_entry_t be_ra_extern_options[] = {
796 LC_OPT_ENT_ENUM_FUNC_PTR("ssa_destr", "SSA destruction flavor", &ssa_destr_var),
797 LC_OPT_ENT_STR("callee", "The external program to call", callee, sizeof(callee)),
801 static be_ra_t be_ra_external_allocator = {
805 void be_init_raextern(void) {
806 lc_opt_entry_t *be_grp = lc_opt_get_grp(firm_opt_get_root(), "be");
807 lc_opt_entry_t *blocksched_grp = lc_opt_get_grp(be_grp, "ra");
808 lc_opt_entry_t *ext_grp = lc_opt_get_grp(blocksched_grp, "ext");
810 lc_opt_add_table(ext_grp, be_ra_extern_options);
812 be_register_allocator("ext", &be_ra_external_allocator);
814 BE_REGISTER_MODULE_CONSTRUCTOR(be_init_raextern);