#include "irnode_t.h"
#include "ircons_t.h"
#include "iredges_t.h"
+#include "ident_t.h"
+#include "type_t.h"
+#include "entity_t.h"
#include "debug.h"
#include "irgwalk.h"
typedef struct _spill_slot_t {
unsigned size;
- unsigned offset;
+ unsigned align;
pset *members;
+ ir_mode *largest_mode; /* the mode of all members with largest size */
} spill_slot_t;
typedef struct _ss_env_t {
/* 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)));
+ ss->largest_mode = get_irn_mode(get_irn_n(spill, 0));
+ ss->size = get_mode_size_bytes(ss->largest_mode);
+ ss->align = ss->size; /* TODO Assumed for now */
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");
+ assert(ss->size == (unsigned)get_mode_size_bytes(get_irn_mode(get_irn_n(spill, 0))) && "Different sizes for the same spill slot are not allowed yet.");
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 */
}
-/* 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) {
+/**
+ * This function should optimize the spill slots.
+ * - Coalescing of multiple slots
+ * - Ordering the slots
+ *
+ * Input slots are in @p ssenv->slots
+ * @p size The count of initial spill slots in @p ssenv->slots
+ * This also is the size of the preallocated array @p ass
+ *
+ * @return An array of spill slots @p ass in specific order
+ **/
+static void optimize_slots(ss_env_t *ssenv, int size, spill_slot_t **ass) {
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)
/* Sort the array to minimize fragmentation and cache footprint.
Large slots come first */
- qsort(ass, count, sizeof(ass[0]), ss_sorter);
+ qsort(ass, size, 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 */
+ for (i=0; i<size; ++i) { /* for each spill slot */
ir_node *n1;
int 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;
}
/* 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);
-
- be_set_Spill_offset(n1, ass[tgt_slot]->offset);
- DBG((ssenv->dbg, LEVEL_1, " Offset %+F %d\n", n1, ass[tgt_slot]->offset));
- }
+ /* NOTE: If src and tgt pset are the same, inserting while iterating is not allowed */
+ if (tgt_slot != i)
+ for(n1 = pset_first(ass[i]->members); n1; n1 = pset_next(ass[i]->members))
+ pset_insert_ptr(ass[tgt_slot]->members, n1);
}
+}
+
+#define ALIGN_SPILL_AREA 16
+#define pset_foreach(pset, elm) for(elm=pset_first(pset); elm; elm=pset_next(pset))
+
+static void assign_entities(ss_env_t *ssenv, int n, spill_slot_t **ss) {
+ int i, offset;
+ ir_type *frame = get_irg_frame_type(ssenv->cenv->irg);
- /* free all used psets, all other stuff is on the ssenv-obstack */
- for (i=0; i<count; ++i)
- del_pset(ass[i]->members);
+ /* aligning by increasing frame size */
+ offset = get_type_size_bits(frame) / 8;
+ offset = round_up2(offset, ALIGN_SPILL_AREA);
+ set_type_size_bytes(frame, -1);
+ /* create entities and assign offsets according to size and alignment*/
+ for (i=0; i<n; ++i) {
+ char buf[64];
+ ident *name, *type_id;
+ entity *spill_ent;
+ ir_node *irn;
+
+ /* build entity */
+ snprintf(buf, sizeof(buf), "spill_slot_%d", i);
+ name = new_id_from_str(buf);
+ snprintf(buf, sizeof(buf), "spill_slot_type_%d", i);
+ type_id = new_id_from_str(buf);
+
+ spill_ent = new_entity(frame, name, new_type_primitive(type_id, ss[i]->largest_mode));
+
+ /* align */
+ offset = round_up2(offset, ss[i]->align);
+ /* set */
+ set_entity_offset_bytes(spill_ent, offset);
+ /* next possible offset */
+ offset += ss[i]->size;
+
+ pset_foreach(ss[i]->members, irn)
+ be_set_Spill_entity(irn, spill_ent);
+ }
+
+ /* set final size of stack frame */
+ set_type_size_bytes(frame, offset);
}
void be_compute_spill_offsets(be_chordal_env_t *cenv) {
ss_env_t ssenv;
+ spill_slot_t **ss;
+ int ss_size;
+ pmap_entry *pme;
obstack_init(&ssenv.ob);
ssenv.cenv = cenv;
ssenv.slots = pmap_create();
ssenv.dbg = firm_dbg_register("ir.be.spillslots");
+ /* Get initial spill slots */
irg_walk_graph(cenv->irg, NULL, compute_spill_slots_walker, &ssenv);
- coalesce_slots(&ssenv);
+ /* Build an empty array for optimized spill slots */
+ ss_size = pmap_count(ssenv.slots);
+ ss = obstack_alloc(&ssenv.ob, ss_size * sizeof(*ss));
+ optimize_slots(&ssenv, ss_size, ss);
+
+ /* Integrate slots into the stack frame entity */
+ assign_entities(&ssenv, ss_size, ss);
+
+ /* Clean up */
+ pmap_foreach(ssenv.slots, pme)
+ del_pset(((spill_slot_t *)pme->value)->members);
pmap_destroy(ssenv.slots);
obstack_free(&ssenv.ob, NULL);
}
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