#include "config.h"
#endif
+#include <stdlib.h>
+
#include "pset.h"
#include "irnode_t.h"
#include "ircons_t.h"
#include "iredges_t.h"
#include "debug.h"
+#include "irgwalk.h"
#include "besched.h"
#include "bespill.h"
ir_node *insert_bl = get_irn_arity(bl) == 1 ? sched_first(bl) : get_Block_cfgpred_block(bl, pos);
be_add_reload(senv, to_spill, insert_bl);
}
+
+
+
+/*
+
+ SPILL SLOT MANAGEMENT AND OPTS
+
+*/
+
+typedef struct _spill_slot_t {
+ unsigned size;
+ unsigned offset;
+ pset *members;
+} spill_slot_t;
+
+typedef struct _ss_env_t {
+ firm_dbg_module_t *dbg;
+ struct obstack ob;
+ be_chordal_env_t *cenv;
+ pmap *slots; /* maps spill_contexts to spill_slots */
+} ss_env_t;
+
+
+static void compute_spill_slots_walker(ir_node *spill, void *env) {
+ ss_env_t *ssenv = env;
+ ir_node *ctx;
+ pmap_entry *entry;
+ spill_slot_t *ss;
+
+ if (!be_is_Spill(spill))
+ return;
+
+ /* check, if this spill is for a context already known */
+ ctx = get_Spill_context(spill);
+ entry = pmap_find(ssenv->slots, ctx);
+
+ if (!entry) {
+ /* this is a new spill context */
+ ss = obstack_alloc(&ssenv->ob, sizeof(*ss));
+ ss->members = pset_new_ptr(8);
+ ss->size = get_mode_size_bytes(get_irn_mode(get_irn_n(spill, 0)));
+ pmap_insert(ssenv->slots, ctx, ss);
+ } else {
+ ir_node *irn;
+ /* values with the same spill_ctx must go into the same spill slot */
+ ss = entry->value;
+ assert(ss->size == (unsigned)get_mode_size_bytes(get_irn_mode(get_irn_n(spill, 0))) && "Different sizes for the same spill slot");
+ for (irn = pset_first(ss->members); irn; irn = pset_next(ss->members)) {
+ /* use values_interfere here, because it uses the dominance check,
+ which does work for values in memory */
+ assert(!values_interfere(spill, irn) && "Spills for the same spill slot must not interfere!");
+ }
+ }
+
+ pset_insert_ptr(ss->members, spill);
+}
+
+static int ss_sorter(const void *v1, const void *v2) {
+ const spill_slot_t *ss1 = v1;
+ const spill_slot_t *ss2 = v2;
+ return ((int) ss2->size) - ((int) ss1->size);
+}
+
+
+/* NOTE/TODO: This function assumes, that all spill slot sizes are a power of 2.
+ Further it assumes, that the alignment is equal to the size and the
+ baseaddr of the spill area is aligned sufficiently for all possible aligments.
+*/
+static void coalesce_slots(ss_env_t *ssenv) {
+ int i, o, used_slots;
+ unsigned curr_offset;
+ pmap_entry *entr;
+ spill_slot_t **ass;
+
+ /* Build an array of all spill slots */
+ int count = pmap_count(ssenv->slots);
+ ass = obstack_alloc(&ssenv->ob, count * sizeof(*ass));
+
+ i=0;
+ pmap_foreach(ssenv->slots, entr)
+ ass[i++] = entr->value;
+
+ /* Sort the array to minimize fragmentation and cache footprint.
+ Large slots come first */
+ qsort(ass, count, sizeof(ass[0]), ss_sorter);
+
+ /* For each spill slot:
+ - assign a new offset to this slot
+ - xor find another slot to coalesce with */
+ curr_offset = 0;
+ used_slots = 0;
+ for (i=0; i<count; ++i) { /* for each spill slot */
+ ir_node *n1;
+ int tgt_slot = -1;
+
+ DBG((ssenv->dbg, LEVEL_1, "Spill slot %d members:\n", i));
+ for(n1 = pset_first(ass[i]->members); n1; n1 = pset_next(ass[i]->members))
+ DBG((ssenv->dbg, LEVEL_1, " %+F\n", n1));
+
+
+ for (o=0; o < used_slots && tgt_slot == -1; ++o) { /* for each offset-assigned spill slot */
+ /* check inter-slot-pairs for interference */
+ ir_node *n2;
+ for(n1 = pset_first(ass[i]->members); n1; n1 = pset_next(ass[i]->members))
+ for(n2 = pset_first(ass[o]->members); n2; n2 = pset_next(ass[o]->members))
+ if(values_interfere(n1, n2)) {
+ pset_break(ass[i]->members);
+ pset_break(ass[o]->members);
+ DBG((ssenv->dbg, LEVEL_1, " Interf %+F -- %+F\n", n1, n2));
+ goto interf_detected;
+ }
+
+ /* if we are here, there is no interference between ass[i] and ass[o] */
+ tgt_slot = o;
+
+interf_detected: /*nothing*/ ;
+ }
+
+ /* now the members of ass[i] join the members of ass[tgt_slot] */
+
+ /* do we need a new slot? */
+ if (tgt_slot == -1) {
+ tgt_slot = used_slots;
+ used_slots++;
+
+ ass[tgt_slot]->offset = curr_offset;
+ curr_offset += ass[i]->size;
+
+ /* init slot */
+ if (tgt_slot != i) {
+ ass[tgt_slot]->size = ass[i]->size;
+ del_pset(ass[tgt_slot]->members);
+ ass[tgt_slot]->members = pset_new_ptr(8);
+ }
+ }
+
+ /* copy the members to the target pset */
+ for(n1 = pset_first(ass[i]->members); n1; n1 = pset_next(ass[i]->members)) {
+ /* NOTE: If src and tgt pset are the same, inserting while iterating is not allowed */
+ if (tgt_slot != i)
+ pset_insert_ptr(ass[tgt_slot]->members, n1);
+
+ set_Spill_offset(n1, ass[tgt_slot]->offset);
+ DBG((ssenv->dbg, LEVEL_1, " Offset %+F %d\n", n1, ass[tgt_slot]->offset));
+ }
+ }
+
+ /* free all used psets, all other stuff is on the ssenv-obstack */
+ for (i=0; i<count; ++i)
+ del_pset(ass[i]->members);
+
+}
+
+void be_compute_spill_offsets(be_chordal_env_t *cenv) {
+ ss_env_t ssenv;
+
+ obstack_init(&ssenv.ob);
+ ssenv.cenv = cenv;
+ ssenv.slots = pmap_create();
+ ssenv.dbg = firm_dbg_register("ir.be.spillslots");
+
+ irg_walk_graph(cenv->irg, NULL, compute_spill_slots_walker, &ssenv);
+ coalesce_slots(&ssenv);
+
+ pmap_destroy(ssenv.slots);
+ obstack_free(&ssenv.ob, NULL);
+}
projects / libfirm / blobdiff