* Date: 20.09.2005
* Copyright: (c) Universitaet Karlsruhe
* Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
+ *
+ * NOTE: Comments my be (partially) wrong, since there was a major bug
+ * (spilling of phis, prespill) whose fixing changed a lot.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#define DBG_FIX 4
#define DBG_DECIDE 8
#define DBG_START 16
+#define DBG_SLOTS 32
#define DBG_TRACE 64
-#define DEBUG_LVL SET_LEVEL_0 //(DBG_START | DBG_DECIDE | DBG_WSETS | DBG_FIX | DBG_SPILL)
+#define DEBUG_LVL 0 //(DBG_START | DBG_DECIDE | DBG_WSETS | DBG_FIX | DBG_SPILL)
static firm_dbg_module_t *dbg = NULL;
#define MIN(a,b) (((a)<(b))?(a):(b))
-#define SINGLE_START_PROJS
+#undef SINGLE_START_PROJS
typedef struct _workset_t workset_t;
typedef struct _belady_env_t {
struct obstack ob;
- const be_node_factory_t *factory;
const arch_env_t *arch;
const arch_register_class_t *cls;
int n_regs; /** number of regs in this reg-class */
struct _workset_t {
belady_env_t *bel;
- int i; /**< used for iteration */
+ int i; /**< used for iteration TODO remove this form the struct */
int len; /**< current length */
loc_t vals[1]; /**< inlined array of the values/distances in this working set */
};
return res;
}
+/**
+ * Alloc a new instance on obstack and make it equal to @param ws
+ */
static INLINE workset_t *workset_clone(struct obstack *ob, workset_t *ws) {
workset_t *res;
size_t size = sizeof(*res) + (ws->bel->n_regs-1)*sizeof(res->vals[0]);
return res;
}
+/**
+ * Do NOT alloc anything. Make @param tgt equal to @param src.
+ * returns @param tgt for convinience
+ */
+static INLINE workset_t *workset_copy(workset_t *tgt, workset_t *src) {
+ size_t size = sizeof(*src) + (src->bel->n_regs-1)*sizeof(src->vals[0]);
+ memcpy(tgt, src, size);
+ return tgt;
+}
+
+/**
+ * Overwrites the current content array of @param ws with the
+ * @param count locations given at memory @param locs.
+ * Set the length of @param ws to count.
+ */
+#define workset_bulk_fill(ws, count, locs) memcpy(&(ws)->vals[0], locs, ((ws)->len=count)*sizeof(locs[0]));
+
+
/**
* Inserts the value @p val into the workset, iff it is not
* already contained. The workset must not be full.
}
}
-/**
- * Overwrites the current contents of @p ws with the
- * locations given in @p locs
- */
-#define workset_bulk_fill(ws, count, locs) memcpy(&(ws)->vals[0], locs, ((ws)->len=count)*sizeof(locs[0]));
-
/**
* Removes all entries from this workset
*/
/**
* 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 ws.
+ * Then it adds the best values (at most n_regs) to the blocks start_workset.
+ * The phis among the remaining values get spilled: Introduce psudo-copies of
+ * their args to break interference and make it possible to spill them to the
+ * same spill slot.
*/
-static void build_start_set(belady_env_t *bel, ir_node *blk) {
- workset_t *ws = bel->ws;
+static void compute_block_start_info(ir_node *blk, void *env) {
+ belady_env_t *bel = env;
+ block_info_t *blk_info;
ir_node *irn, *first;
irn_live_t *li;
- int count;
+ int i, count, ws_count;
loc_t loc, *starters;
+ ir_graph *irg = get_irn_irg(blk);
struct obstack ob;
obstack_init(&ob);
- /* get all values */
+ /* Get all values living at the block start */
+ DBG((dbg, DBG_START, "Living at start of %+F:\n", blk));
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) {
loc.irn = irn;
loc.time = be_get_next_use(bel->uses, first, 0, irn, 0);
- DBG((dbg, DBG_START, " %+F next-use %d\n", loc.irn, loc.time));
obstack_grow(&ob, &loc, sizeof(loc));
+ DBG((dbg, DBG_START, " %+F:\n", irn));
count++;
} else
break;
if (live_is_in(li) && arch_get_irn_reg_class(bel->arch, li->irn, -1) == bel->cls) {
loc.irn = (ir_node *)li->irn;
loc.time = be_get_next_use(bel->uses, first, 0, li->irn, 0);
- DBG((dbg, DBG_START, " %+F next-use %d\n", loc.irn, loc.time));
obstack_grow(&ob, &loc, sizeof(loc));
+ DBG((dbg, DBG_START, " %+F:\n", irn));
count++;
}
starters = obstack_finish(&ob);
- /* sort all values */
+ /* Sort all values */
qsort(starters, count, sizeof(starters[0]), loc_compare);
- /* copy the best ones to the ws */
- count = MIN(count, ws->bel->n_regs);
- workset_bulk_fill(ws, count, starters);
+ /* Create the start workset for this block. Copy the best ones from starters */
+ blk_info = obstack_alloc(&bel->ob, sizeof(*blk_info));
+ set_irn_link(blk, blk_info);
+
+ ws_count = MIN(count, bel->n_regs);
+ blk_info->ws_start = new_workset(&bel->ob, bel);
+ workset_bulk_fill(blk_info->ws_start, ws_count, starters);
+
+ /* Spill the phis among the remaining values */
+ for (i=ws_count; i<count; ++i) {
+ int o, max;
+
+ irn = starters[i].irn;
+ if (!is_Phi(irn) || get_nodes_block(irn) != blk)
+ continue;
+
+ 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);
+ DBG((dbg, DBG_START, " place a %+F of %+F in %+F\n", cpy, arg, pred_block));
+ sched_add_before(pred_block, cpy);
+ set_irn_n(irn, o, cpy);
+ }
+ }
obstack_free(&ob, NULL);
}
* whether it is used from a register or is reloaded
* before the use.
*/
-static void decide(ir_node *blk, void *env) {
+static void belady(ir_node *blk, void *env) {
belady_env_t *bel = env;
workset_t *new_vals;
ir_node *irn;
#ifdef SINGLE_START_PROJS
ir_node *start_blk = get_irg_start_block(get_irn_irg(blk));
#endif
- block_info_t *blk_info = obstack_alloc(&bel->ob, sizeof(*blk_info));
- set_irn_link(blk, blk_info);
+ block_info_t *blk_info = get_irn_link(blk);
DBG((dbg, DBG_DECIDE, "\n"));
DBG((dbg, DBG_DECIDE, "Decide for %+F\n", blk));
- /* build starting-workset for this block */
- build_start_set(bel, blk);
- blk_info->ws_start = workset_clone(&bel->ob, bel->ws);
+ workset_copy(bel->ws, blk_info->ws_start);
DBG((dbg, DBG_WSETS, "Initial start workset for %+F:\n", blk));
- workset_foreach(blk_info->ws_start, irn)
+ workset_foreach(bel->ws, irn)
DBG((dbg, DBG_WSETS, " %+F\n", irn));
/* process the block from start to end */
* Removes all used reloads from bel->reloads.
* The remaining nodes in bel->reloads will be removed from the graph.
*/
-static void rescue_used_reloads(ir_node *irn, void *env) {
+static void rescue_used_reloads_and_remove_copies(ir_node *irn, void *env) {
pset *rlds = (pset *)env;
if (pset_find_ptr(rlds, irn))
pset_remove_ptr(rlds, irn);
+
+
+ /* remove copies introduced for phi-spills */
+ if (be_is_Copy(irn)) {
+ ir_node *src, *spill;
+ assert(get_irn_n_edges(irn) == 1 && "This is not a copy introduced in 'compute_block_start_info()'. Who created it?");
+
+ spill = get_irn_edge(get_irn_irg(irn), irn, 0)->src;
+ assert(be_is_Spill(spill) && "This is not a copy introduced in 'compute_block_start_info()'. Who created it?");
+
+ src = get_irn_n(irn, 0);
+ set_irn_n(spill, 0, src);
+ }
}
/**
* Finds all unused reloads and remove them from the schedule
* Also removes spills if they are not used anymore after removing reloads
*/
-static void remove_unused_reloads(ir_graph *irg, belady_env_t *bel) {
+static void remove_copies_and_unused_reloads(ir_graph *irg, belady_env_t *bel) {
ir_node *irn;
- irg_walk_graph(irg, rescue_used_reloads, NULL, bel->reloads);
+ irg_walk_graph(irg, rescue_used_reloads_and_remove_copies, NULL, bel->reloads);
for(irn = pset_first(bel->reloads); irn; irn = pset_next(bel->reloads)) {
ir_node *spill;
DBG((dbg, DBG_SPILL, "Removing %+F before %+F in %+F\n", irn, sched_next(irn), get_nodes_block(irn)));
/* init belady env */
obstack_init(&bel.ob);
- bel.factory = chordal_env->main_env->node_factory;
bel.arch = chordal_env->main_env->arch_env;
bel.cls = chordal_env->cls;
bel.n_regs = arch_register_class_n_regs(bel.cls);
bel.reloads = pset_new_ptr_default();
/* do the work */
- irg_block_walk_graph(chordal_env->irg, decide, NULL, &bel);
+ irg_block_walk_graph(chordal_env->irg, compute_block_start_info, NULL, &bel);
+ irg_block_walk_graph(chordal_env->irg, belady, NULL, &bel);
irg_block_walk_graph(chordal_env->irg, fix_block_borders, NULL, &bel);
be_insert_spills_reloads(bel.senv, bel.reloads);
- remove_unused_reloads(chordal_env->irg, &bel);
+ remove_copies_and_unused_reloads(chordal_env->irg, &bel);
+
/* clean up */
del_pset(bel.reloads);
projects / libfirm / blobdiff