ir_node *instr; /**< current instruction */
unsigned instr_nr; /**< current instruction number (relative to block start) */
pset *used; /**< holds the values used (so far) in the current BB */
- pset *copies; /**< holds all copies placed due to phi-spilling */
+ ir_node **copies; /**< holds all copies placed due to phi-spilling */
spill_env_t *senv; /**< see bespill.h */
} belady_env_t;
static void belady(ir_node *blk, void *env);
+/**
+ * Inserts a spill of a value at the earliest possible location in a block.
+ * That is after the last use of the value or at the beginning of the block if
+ * there is no use
+ */
+static ir_node *insert_copy(belady_env_t *env, ir_node *block, ir_node *value) {
+ ir_node* node;
+ ir_graph *irg = get_irn_irg(block);
+ ir_node *copy = be_new_Copy(env->cls, irg, block, value);
+
+ ARR_APP1(ir_node*, env->copies, copy);
+
+ // walk schedule backwards until we find a usage, or until we have reached the first phi
+ // TODO can we do this faster somehow? This makes insert_copy O(n) in block_size...
+ sched_foreach_reverse(block, node) {
+ int i, arity;
+
+ if(is_Phi(node)) {
+ sched_add_after(node, copy);
+ goto placed;
+ }
+ if(value == node) {
+ sched_add_after(node, copy);
+ goto placed;
+ }
+ for(i = 0, arity = get_irn_arity(node); i < arity; ++i) {
+ ir_node *arg = get_irn_n(node, i);
+ if(arg == value) {
+ sched_add_after(node, copy);
+ goto placed;
+ }
+ }
+ }
+ // we didn't find a use or a phi yet, so place the copy at the beginning of the block
+ sched_add_before(sched_first(block), copy);
+
+placed:
+
+ return copy;
+}
+
/**
* Collects all values live-in at block @p blk and all phi results in this block.
* Then it adds the best values (at most n_regs) to the blocks start_workset.
* their args to break interference and make it possible to spill them to the
* same spill slot.
*/
-static block_info_t *compute_block_start_info(ir_node *blk, void *env) {
- belady_env_t *bel = env;
+static block_info_t *compute_block_start_info(ir_node *blk, void *data) {
+ belady_env_t *env = data;
ir_node *irn, *first;
irn_live_t *li;
int i, count, ws_count;
return res;
/* Create the block info for this block. */
- res = new_block_info(&bel->ob);
+ res = new_block_info(&env->ob);
set_block_info(blk, res);
first = sched_first(blk);
count = 0;
sched_foreach(blk, irn) {
- if (is_Phi(irn) && arch_get_irn_reg_class(bel->arch, irn, -1) == bel->cls) {
+ if (is_Phi(irn) && arch_get_irn_reg_class(env->arch, irn, -1) == env->cls) {
loc.irn = irn;
- loc.time = get_distance(bel, first, 0, irn, 0);
+ loc.time = get_distance(env, first, 0, irn, 0);
obstack_grow(&ob, &loc, sizeof(loc));
DBG((dbg, DBG_START, " %+F:\n", irn));
count++;
}
live_foreach(blk, li) {
- if (live_is_in(li) && arch_get_irn_reg_class(bel->arch, li->irn, -1) == bel->cls) {
+ if (live_is_in(li) && arch_get_irn_reg_class(env->arch, li->irn, -1) == env->cls) {
loc.irn = (ir_node *)li->irn;
- loc.time = get_distance(bel, first, 0, li->irn, 0);
+ loc.time = get_distance(env, first, 0, li->irn, 0);
obstack_grow(&ob, &loc, sizeof(loc));
DBG((dbg, DBG_START, " %+F:\n", li->irn));
count++;
/* if pred block has not been processed yet, do it now */
if (! pred_info) {
- belady(pred_blk, bel);
+ belady(pred_blk, env);
pred_info = get_block_info(pred_blk);
}
/* now we have an end_set of pred */
assert(pred_info->ws_end && "The recursive call (above) is supposed to compute an end_set");
- res->ws_start = workset_clone(&bel->ob, pred_info->ws_end);
+ res->ws_start = workset_clone(&env->ob, pred_info->ws_end);
} else
/* Else we want the start_set to be the values used 'the closest' */
{
/* Copy the best ones from starters to start workset */
- ws_count = MIN(count, bel->n_regs);
- res->ws_start = new_workset(&bel->ob, bel);
+ ws_count = MIN(count, env->n_regs);
+ res->ws_start = new_workset(&env->ob, env);
workset_bulk_fill(res->ws_start, ws_count, starters);
}
+
/* The phis of this block which are not in the start set have to be spilled later.
* Therefore we add temporary copies in the pred_blocks so the spills can spill
* into the same spill slot.
DBG((dbg, DBG_START, "For %+F:\n", irn));
for (max=get_irn_arity(irn), o=0; o<max; ++o) {
- ir_node *arg = get_irn_n(irn, o);
ir_node *pred_block = get_Block_cfgpred_block(get_nodes_block(irn), o);
- ir_node *cpy = be_new_Copy(bel->cls, irg, pred_block, arg);
- pset_insert_ptr(bel->copies, cpy);
- DBG((dbg, DBG_START, " place a %+F of %+F in %+F\n", cpy, arg, pred_block));
- /* TODO: Place copies before jumps! */
- sched_add_before(sched_last(pred_block), cpy);
- set_irn_n(irn, o, cpy);
+ ir_node *arg = get_irn_n(irn, o);
+ ir_node* copy = insert_copy(env, pred_block, arg);
+
+ set_irn_n(irn, o, copy);
}
}
/**
* Removes all copies introduced for phi-spills
*/
-static void remove_copies(belady_env_t *bel) {
- ir_node *irn;
+static void remove_copies(belady_env_t *env) {
+ int i;
- foreach_pset(bel->copies, irn) {
+ for(i = 0; i < ARR_LEN(env->copies); ++i) {
+ ir_node *node = env->copies[i];
ir_node *src;
const ir_edge_t *edge, *ne;
- assert(be_is_Copy(irn));
+ assert(be_is_Copy(node));
- src = be_get_Copy_op(irn);
- foreach_out_edge_safe(irn, edge, ne) {
+ src = be_get_Copy_op(node);
+ foreach_out_edge_safe(node, edge, ne) {
ir_node *user = get_edge_src_irn(edge);
int user_pos = get_edge_src_pos(edge);
be_set_is_spilled_phi(bel.senv, is_mem_phi, NULL);
}
DEBUG_ONLY(be_set_spill_env_dbg_module(bel.senv, dbg);)
- bel.copies = pset_new_ptr_default();
+ bel.copies = NEW_ARR_F(ir_node*, 0);
DBG((dbg, LEVEL_1, "running on register class: %s\n", bel.cls->name));
irg_block_walk_graph(chordal_env->irg, fix_block_borders, NULL, &bel);
be_insert_spills_reloads(bel.senv);
remove_copies(&bel);
+ DEL_ARR_F(bel.copies);
be_remove_dead_nodes_from_schedule(chordal_env->irg);
projects / libfirm / blobdiff