+/*
+ * Copyright (C) 1995-2007 University of Karlsruhe. All right reserved.
+ *
+ * This file is part of libFirm.
+ *
+ * This file may be distributed and/or modified under the terms of the
+ * GNU General Public License version 2 as published by the Free Software
+ * Foundation and appearing in the file LICENSE.GPL included in the
+ * packaging of this file.
+ *
+ * Licensees holding valid libFirm Professional Edition licenses may use
+ * this file in accordance with the libFirm Commercial License.
+ * Agreement provided with the Software.
+ *
+ * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
+ * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE.
+ */
+
/**
- * Author: Daniel Grund
- * Date: 20.09.2005
- * Copyright: (c) Universitaet Karlsruhe
- * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
+ * @file
+ * @brief Beladys spillalgorithm.
+ * @author Daniel Grund, Matthias Braun
+ * @date 20.09.2005
+ * @version $Id$
*/
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
-#include <alloca.h>
#include "obst.h"
-#include "set.h"
-#include "pset.h"
+#include "irprintf_t.h"
#include "irgraph.h"
#include "irnode.h"
#include "irmode.h"
#include "irgwalk.h"
+#include "irloop.h"
#include "iredges_t.h"
#include "ircons_t.h"
+#include "irprintf.h"
+#include "irnodeset.h"
+#include "xmalloc.h"
+#include "pdeq.h"
#include "beutil.h"
-#include "bearch.h"
-#include "bespillbelady.h"
-#include "beuses_t.h"
+#include "bearch_t.h"
+#include "beuses.h"
#include "besched_t.h"
#include "beirgmod.h"
#include "belive_t.h"
#include "benode_t.h"
+#include "bechordal_t.h"
+#include "bespilloptions.h"
+#include "beloopana.h"
+#include "beirg_t.h"
+#include "bespill.h"
+#include "bemodule.h"
+
+#define DBG_SPILL 1
+#define DBG_WSETS 2
+#define DBG_FIX 4
+#define DBG_DECIDE 8
+#define DBG_START 16
+#define DBG_SLOTS 32
+#define DBG_TRACE 64
+#define DBG_WORKSET 128
+DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
+
+/* factor to weight the different costs of reloading/rematerializing a node
+ (see bespill.h be_get_reload_costs_no_weight) */
+#define RELOAD_COST_FACTOR 10
+
+typedef enum {
+ value_not_reloaded, /* the value has not been reloaded */
+ value_partially_reloaded, /* the value has been reloaded on some paths */
+ value_reloaded /* the value has been reloaded on all paths */
+} reloaded_state_t;
-#define DBG_SPILL 1
-#define DBG_WSETS 2
-#define DBG_FIX 4
-#define DBG_DECIDE 8
-#define DBG_START 16
-#define DBG_TRACE 64
-#define DEBUG_LVL SET_LEVEL_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
-
-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 */
-
- workset_t *ws; /**< the main workset used while processing a block. ob-allocated */
- be_uses_t *uses; /**< env for the next-use magic */
- 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 */
-
- spill_env_t *senv; /* see bespill.h */
- pset *reloads; /**< all reload nodes placed */
-} belady_env_t;
-
-struct _workset_t {
- belady_env_t *bel;
- int i; /**< used for iteration */
- int len; /**< current length */
- loc_t vals[1]; /**< inlined array of the values/distances in this working set */
-};
-
-typedef struct _block_info_t {
- workset_t *ws_start, *ws_end;
-} block_info_t;
+/**
+ * An association between a node and a point in time.
+ */
+typedef struct loc_t {
+ ir_node *node;
+ unsigned time; /**< A use time (see beuses.h). */
+ reloaded_state_t reloaded; /**< the value is a reloaded value */
+} loc_t;
+
+typedef struct _workset_t {
+ int len; /**< current length */
+ loc_t vals[0]; /**< inlined array of the values/distances in this working set */
+} workset_t;
+
+static struct obstack obst;
+static const arch_env_t *arch_env;
+static const arch_register_class_t *cls;
+static const be_lv_t *lv;
+static be_loopana_t *loop_ana;
+static int n_regs;
+static workset_t *ws; /**< the main workset used while
+ processing a block. */
+static be_uses_t *uses; /**< env for the next-use magic */
+static ir_node *instr; /**< current instruction */
+static unsigned instr_nr; /**< current instruction number
+ (relative to block start) */
+static ir_nodeset_t used;
+static spill_env_t *senv; /**< see bespill.h */
+static pdeq *worklist;
+
+static int loc_compare(const void *a, const void *b)
+{
+ const loc_t *p = a;
+ const loc_t *q = b;
+ return p->time - q->time;
+}
+
+void workset_print(const workset_t *w)
+{
+ int i;
+
+ for(i = 0; i < w->len; ++i) {
+ ir_fprintf(stderr, "%+F %d\n", w->vals[i].node, w->vals[i].time);
+ }
+}
/**
* Alloc a new workset on obstack @p ob with maximum size @p max
*/
-static INLINE workset_t *new_workset(struct obstack *ob, belady_env_t *bel) {
+static workset_t *new_workset(void)
+{
workset_t *res;
- size_t size = sizeof(*res) + (bel->n_regs-1)*sizeof(res->vals[0]);
- res = obstack_alloc(ob, size);
+ size_t size = sizeof(*res) + n_regs * sizeof(res->vals[0]);
+
+ res = obstack_alloc(&obst, size);
memset(res, 0, size);
- res->bel = bel;
return res;
}
-static INLINE workset_t *workset_clone(struct obstack *ob, workset_t *ws) {
+/**
+ * Alloc a new instance on obstack and make it equal to @param workset
+ */
+static workset_t *workset_clone(workset_t *workset)
+{
workset_t *res;
- size_t size = sizeof(*res) + (ws->bel->n_regs-1)*sizeof(res->vals[0]);
- res = obstack_alloc(ob, size);
- memcpy(res, ws, size);
+ size_t size = sizeof(*res) + n_regs * sizeof(res->vals[0]);
+ res = obstack_alloc(&obst, size);
+ memcpy(res, workset, size);
return res;
}
/**
- * Inserts the value @p val into the workset, iff it is not
- * already contained. The workset must not be full.
+ * Copy workset @param src to @param tgt
*/
-static INLINE void workset_insert(workset_t *ws, ir_node *val) {
- int i;
- /* check for current regclass */
- if (arch_get_irn_reg_class(ws->bel->arch, val, -1) != ws->bel->cls) {
- DBG((dbg, DBG_DECIDE, "Dropped %+F\n", val));
- return;
- }
-
- /* check if val is already contained */
- for(i=0; i<ws->len; ++i)
- if (ws->vals[i].irn == val)
- return;
+static void workset_copy(workset_t *dest, const workset_t *src)
+{
+ size_t size = sizeof(*src) + n_regs * sizeof(src->vals[0]);
+ memcpy(dest, src, size);
+}
- /* insert val */
- assert(ws->len < ws->bel->n_regs && "Workset already full!");
- ws->vals[ws->len++].irn = val;
+/**
+ * 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.
+ */
+static void workset_bulk_fill(workset_t *workset, int count, const loc_t *locs)
+{
+ workset->len = count;
+ memcpy(&(workset->vals[0]), locs, count * sizeof(locs[0]));
}
/**
- * Inserts all values in array @p vals of length @p cnt
- * into the workset. There must be enough space for the
- * entries.
+ * Inserts the value @p val into the workset, iff it is not
+ * already contained. The workset must not be full.
*/
-static INLINE void workset_bulk_insert(workset_t *ws, int cnt, ir_node **vals) {
- int i, o;
-
- for(o=0; o<cnt; ++o) {
- ir_node *val = vals[o];
- DBG((dbg, DBG_TRACE, "Bulk insert %+F\n", val));
- /* check for current regclass */
- if (arch_get_irn_reg_class(ws->bel->arch, val, -1) != ws->bel->cls) {
- DBG((dbg, DBG_TRACE, "Wrong reg class\n"));
- goto no_insert;
- }
+static void workset_insert(workset_t *workset, ir_node *val, int reloaded)
+{
+ loc_t *loc;
+ int i;
+ /* check for current regclass */
+ assert(arch_irn_consider_in_reg_alloc(arch_env, cls, val));
- /* check if val is already contained */
- for(i=0; i<ws->len; ++i)
- if (ws->vals[i].irn == val) {
- DBG((dbg, DBG_TRACE, "Already contained\n"));
- goto no_insert;
+ /* check if val is already contained */
+ for (i = 0; i < workset->len; ++i) {
+ loc = &workset->vals[i];
+ if (loc->node == val) {
+ if(!loc->reloaded) {
+ loc->reloaded = reloaded;
}
-
- /* insert val */
- assert(ws->len < ws->bel->n_regs && "Workset does not have enough room!");
- ws->vals[ws->len++].irn = val;
- DBG((dbg, DBG_TRACE, "Inserted\n"));
-
-no_insert:
- /*epsilon statement :)*/;
+ return;
+ }
}
-}
-/**
- * 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]));
+ /* insert val */
+ assert(workset->len < n_regs && "Workset already full!");
+ loc = &workset->vals[workset->len];
+ loc->node = val;
+ loc->reloaded = reloaded;
+ loc->time = 6666; /* undefined yet */
+ workset->len++;
+}
/**
* Removes all entries from this workset
*/
-#define workset_clear(ws) (ws)->len = 0;
+static void workset_clear(workset_t *workset)
+{
+ workset->len = 0;
+}
/**
* Removes the value @p val from the workset if present.
*/
-static INLINE void workset_remove(workset_t *ws, ir_node *val) {
+static INLINE void workset_remove(workset_t *workset, ir_node *val)
+{
int i;
- for(i=0; i<ws->len; ++i)
- if (ws->vals[i].irn == val) {
- ws->vals[i] = ws->vals[--ws->len];
+ for(i = 0; i < workset->len; ++i) {
+ if (workset->vals[i].node == val) {
+ workset->vals[i] = workset->vals[--workset->len];
return;
}
+ }
}
-static INLINE int workset_contains(const workset_t *ws, const ir_node *val) {
+static INLINE int workset_contains(const workset_t *ws, const ir_node *val)
+{
int i;
- for(i=0; i<ws->len; ++i)
- if (ws->vals[i].irn == val)
+
+ for(i=0; i<ws->len; ++i) {
+ if (ws->vals[i].node == val)
return 1;
+ }
+
return 0;
}
-#define workset_foreach(ws, v) for(ws->i=0; \
- v=(ws->i < ws->len) ? ws->vals[ws->i].irn : NULL, ws->i < ws->len; \
- ws->i++)
+/**
+ * Iterates over all values in the working set.
+ * @p ws The workset to iterate
+ * @p v A variable to put the current value in
+ * @p i An integer for internal use
+ */
+#define workset_foreach(ws, v, i) for(i=0; \
+ v=(i < ws->len) ? ws->vals[i].node : NULL, i < ws->len; \
+ ++i)
#define workset_set_time(ws, i, t) (ws)->vals[i].time=t
+#define workset_get_time(ws, i) (ws)->vals[i].time
#define workset_set_length(ws, length) (ws)->len = length
#define workset_get_length(ws) ((ws)->len)
-#define workset_get_val(ws, i) ((ws)->vals[i].irn)
+#define workset_get_val(ws, i) ((ws)->vals[i].node)
#define workset_sort(ws) qsort((ws)->vals, (ws)->len, sizeof((ws)->vals[0]), loc_compare);
+typedef struct _block_info_t
+{
+ workset_t *start_workset;
+ workset_t *end_workset;
+} block_info_t;
+
+
+static void *new_block_info(void)
+{
+ block_info_t *res = obstack_alloc(&obst, sizeof(res[0]));
+ memset(res, 0, sizeof(res[0]));
-static int is_mem_phi(const ir_node *irn, void *data) {
- ir_node *blk = get_nodes_block(irn);
- DBG((dbg, DBG_SPILL, "Is %+F a mem-phi?\n", irn));
- workset_t *sws = ((block_info_t *)get_irn_link(blk))->ws_start;
- DBG((dbg, DBG_SPILL, " %d\n", !workset_contains(sws, irn)));
- return !workset_contains(sws, irn);
+ return res;
}
+#define get_block_info(block) ((block_info_t *)get_irn_link(block))
+#define set_block_info(block, info) set_irn_link(block, info)
+
/**
- * 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.
+ * @return The distance to the next use or 0 if irn has dont_spill flag set
*/
-static void build_start_set(belady_env_t *bel, ir_node *blk) {
- workset_t *ws = bel->ws;
- ir_node *irn, *first;
- irn_live_t *li;
- int count;
- loc_t loc, *starters;
- struct obstack ob;
-
- obstack_init(&ob);
-
- /* get all values */
- 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));
- count++;
- } else
- break;
+static INLINE unsigned get_distance(ir_node *from, unsigned from_step,
+ const ir_node *def, int skip_from_uses)
+{
+ be_next_use_t use;
+ int flags = arch_irn_get_flags(arch_env, def);
+ unsigned costs;
+ unsigned time;
- live_foreach(blk, li)
- 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));
- count++;
- }
- starters = obstack_finish(&ob);
+ assert(! (flags & arch_irn_flags_ignore));
- /* sort all values */
- qsort(starters, count, sizeof(starters[0]), loc_compare);
+ use = be_get_next_use(uses, from, from_step, def, skip_from_uses);
+ if(USES_IS_INFINITE(use.time))
+ return USES_INFINITY;
- /* copy the best ones to the ws */
- count = MIN(count, ws->bel->n_regs);
- workset_bulk_fill(ws, count, starters);
+ /* We have to keep nonspillable nodes in the workingset */
+ if(flags & arch_irn_flags_dont_spill)
+ return 0;
- obstack_free(&ob, NULL);
+ costs = be_get_reload_costs_no_weight(senv, def, use.before);
+ assert(costs * RELOAD_COST_FACTOR < 1000);
+ time = use.time + 1000 - (costs * RELOAD_COST_FACTOR);
+
+ return time;
}
/**
- * Performs the actions neccessary to grant the request that:
+ * Performs the actions necessary to grant the request that:
* - new_vals can be held in registers
* - as few as possible other values are disposed
* - the worst values get disposed
* @p is_usage indicates that the values in new_vals are used (not defined)
* In this case reloads must be performed
*/
-static void displace(belady_env_t *bel, workset_t *new_vals, int is_usage) {
- ir_node *val;
- int i, len, max_allowed, demand;
- workset_t *ws = bel->ws;
- ir_node **to_insert = alloca(bel->n_regs * sizeof(*to_insert));
-
- /*
- * 1. Identify the number of needed slots and the values to reload
- */
+static void displace(workset_t *new_vals, int is_usage)
+{
+ ir_node **to_insert = alloca(n_regs * sizeof(to_insert[0]));
+ ir_node *val;
+ int i;
+ int len;
+ int spills_needed;
+ int demand;
+ int iter;
+
+ /* 1. Identify the number of needed slots and the values to reload */
demand = 0;
- workset_foreach(new_vals, val) {
+ workset_foreach(new_vals, val, iter) {
/* mark value as used */
if (is_usage)
- pset_insert_ptr(bel->used, val);
+ ir_nodeset_insert(&used, val);
- if (!workset_contains(ws, val)) {
+ if (! workset_contains(ws, val)) {
DBG((dbg, DBG_DECIDE, " insert %+F\n", val));
- to_insert[demand++] = val;
- if (is_usage)
- be_add_reload(bel->senv, val, bel->instr);
- } else
- DBG((dbg, DBG_DECIDE, " skip %+F\n", val));
+ if (is_usage) {
+ DBG((dbg, DBG_SPILL, "Reload %+F before %+F\n", val, instr));
+ be_add_reload(senv, val, instr, cls, 1);
+ }
+ } else {
+ DBG((dbg, DBG_DECIDE, " %+F already in workset\n", val));
+ assert(is_usage);
+ /* remove the value from the current workset so it is not accidently
+ * spilled */
+ workset_remove(ws, val);
+ }
+ to_insert[demand++] = val;
}
- DBG((dbg, DBG_DECIDE, " demand = %d\n", demand));
-
- /*
- * 2. Make room for at least 'demand' slots
- */
- len = workset_get_length(ws);
- max_allowed = bel->n_regs - demand;
+ /* 2. Make room for at least 'demand' slots */
+ len = workset_get_length(ws);
+ spills_needed = len + demand - n_regs;
+ assert(spills_needed <= len);
/* Only make more free room if we do not have enough */
- if (len > max_allowed) {
- /* get current next-use distance */
- for (i=0; i<ws->len; ++i)
- workset_set_time(ws, i, be_get_next_use(bel->uses, bel->instr, bel->instr_nr, workset_get_val(ws, i), !is_usage));
+ if (spills_needed > 0) {
+ ir_node *curr_bb = get_nodes_block(instr);
+ workset_t *ws_start = get_block_info(curr_bb)->start_workset;
+
+ DBG((dbg, DBG_DECIDE, " disposing %d values\n", spills_needed));
+
+ /* calculate current next-use distance for live values */
+ for (i = 0; i < len; ++i) {
+ ir_node *val = workset_get_val(ws, i);
+ unsigned dist = get_distance(instr, instr_nr, val, !is_usage);
+ workset_set_time(ws, i, dist);
+ }
/* sort entries by increasing nextuse-distance*/
workset_sort(ws);
/* Logic for not needed live-ins: If a value is disposed
- before its first usage, remove it from start workset */
- for (i=max_allowed; i<ws->len; ++i) {
- ir_node *irn = ws->vals[i].irn;
- if (!pset_find_ptr(bel->used, irn)) {
- ir_node *curr_bb = get_nodes_block(bel->instr);
- workset_t *ws_start = ((block_info_t *) get_irn_link(curr_bb))->ws_start;
- workset_remove(ws_start, irn);
-
- DBG((dbg, DBG_DECIDE, " dispose %+F dumb\n", irn));
- } else
- DBG((dbg, DBG_DECIDE, " dispose %+F\n", irn));
+ * before its first usage, remove it from start workset
+ * We don't do this for phis though */
+ for (i = len - spills_needed; i < len; ++i) {
+ ir_node *val = ws->vals[i].node;
+
+ DBG((dbg, DBG_DECIDE, " disposing node %+F (%u)\n", val,
+ workset_get_time(ws, i)));
+
+ if(!USES_IS_INFINITE(ws->vals[i].time)
+ && !ws->vals[i].reloaded) {
+ //be_add_spill(senv, val, instr);
+ }
+
+ if (! ir_nodeset_contains(&used, val)) {
+ workset_remove(ws_start, val);
+ DBG((dbg, DBG_DECIDE, " (and removing %+F from start workset)\n", val));
+ }
}
/* kill the last 'demand' entries in the array */
- workset_set_length(ws, max_allowed);
+ workset_set_length(ws, len - spills_needed);
+ }
+
+ /* 3. Insert the new values into the workset */
+ for (i = 0; i < demand; ++i) {
+ ir_node *val = to_insert[i];
+
+ workset_insert(ws, val, 1);
+ }
+}
+
+/** Decides whether a specific node should be in the start workset or not
+ *
+ * @param env belady environment
+ * @param first
+ * @param node the node to test
+ * @param loop the loop of the node
+ */
+static loc_t to_take_or_not_to_take(ir_node* first, ir_node *node,
+ ir_loop *loop)
+{
+ be_next_use_t next_use;
+ loc_t loc;
+
+ loc.time = USES_INFINITY;
+ loc.node = node;
+ //loc.reloaded = rand() % 2; /* provoke a bug... */
+ loc.reloaded = 0;
+
+ if (!arch_irn_consider_in_reg_alloc(arch_env, cls, node)) {
+ loc.time = USES_INFINITY;
+ return loc;
+ }
+
+ /* We have to keep nonspillable nodes in the workingset */
+ if(arch_irn_get_flags(arch_env, node) & arch_irn_flags_dont_spill) {
+ loc.time = 0;
+ DBG((dbg, DBG_START, " %+F taken (dontspill node)\n", node, loc.time));
+ return loc;
+ }
+
+ next_use = be_get_next_use(uses, first, 0, node, 0);
+ if(USES_IS_INFINITE(next_use.time)) {
+ // the nodes marked as live in shouldn't be dead, so it must be a phi
+ assert(is_Phi(node));
+ loc.time = USES_INFINITY;
+ DBG((dbg, DBG_START, " %+F not taken (dead)\n", node));
+ if(is_Phi(node)) {
+ be_spill_phi(senv, node);
+ }
+ return loc;
}
- /*
- * 3. Insert the new values into the workset
- */
- workset_bulk_insert(bel->ws, demand, to_insert);
+ loc.time = next_use.time;
+
+ if(next_use.outermost_loop >= get_loop_depth(loop)) {
+ DBG((dbg, DBG_START, " %+F taken (%u, loop %d)\n", node, loc.time, next_use.outermost_loop));
+ } else {
+ loc.time = USES_PENDING;
+ DBG((dbg, DBG_START, " %+F delayed (outerloopdepth %d < loopdetph %d)\n", node, next_use.outermost_loop, get_loop_depth(loop)));
+ }
+ return loc;
}
/**
- * For the given block @p blk, decide for each values
+ * Computes the start-workset for a block with multiple predecessors. We assume
+ * that at least 1 of the predeccesors is a back-edge which means we're at the
+ * beginning of a loop. We try to reload as much values as possible now so they
+ * don't get reloaded inside the loop.
+ */
+static void compute_live_ins(const ir_node *block)
+{
+ ir_loop *loop = get_irn_loop(block);
+ ir_node *first;
+ ir_node *node;
+ loc_t loc;
+ loc_t *starters;
+ loc_t *delayed;
+ int i, len, ws_count;
+ int free_slots, free_pressure_slots;
+ unsigned pressure;
+ //int arity;
+ //int n_pred_worksets;
+ //workset_t **pred_worksets;
+
+ /* Collect all values living at start of block */
+ starters = NEW_ARR_F(loc_t, 0);
+ delayed = NEW_ARR_F(loc_t, 0);
+
+ DBG((dbg, DBG_START, "Living at start of %+F:\n", block));
+ first = sched_first(block);
+
+ /* check all Phis first */
+ sched_foreach(block, node) {
+ if (! is_Phi(node))
+ break;
+
+ loc = to_take_or_not_to_take(first, node, loop);
+
+ if (! USES_IS_INFINITE(loc.time)) {
+ if (USES_IS_PENDING(loc.time))
+ ARR_APP1(loc_t, delayed, loc);
+ else
+ ARR_APP1(loc_t, starters, loc);
+ }
+ }
+
+ /* check all Live-Ins */
+ be_lv_foreach(lv, block, be_lv_state_in, i) {
+ ir_node *node = be_lv_get_irn(lv, block, i);
+
+ loc = to_take_or_not_to_take(first, node, loop);
+
+ if (! USES_IS_INFINITE(loc.time)) {
+ if (USES_IS_PENDING(loc.time))
+ ARR_APP1(loc_t, delayed, loc);
+ else
+ ARR_APP1(loc_t, starters, loc);
+ }
+ }
+
+ pressure = be_get_loop_pressure(loop_ana, cls, loop);
+ assert(ARR_LEN(delayed) <= (signed)pressure);
+ free_slots = n_regs - ARR_LEN(starters);
+ free_pressure_slots = n_regs - (pressure - ARR_LEN(delayed));
+ free_slots = MIN(free_slots, free_pressure_slots);
+
+ /* so far we only put nodes into the starters list that are used inside
+ * the loop. If register pressure in the loop is low then we can take some
+ * values and let them live through the loop */
+ if(free_slots > 0) {
+ qsort(delayed, ARR_LEN(delayed), sizeof(delayed[0]), loc_compare);
+
+ for (i = 0; i < ARR_LEN(delayed) && i < free_slots; ++i) {
+ DBG((dbg, DBG_START, " delayed %+F taken\n", delayed[i].node));
+ ARR_APP1(loc_t, starters, delayed[i]);
+ delayed[i].node = NULL;
+ }
+ }
+
+ /* spill phis (the actual phis not just their values) that are in this block
+ * but not in the start workset */
+ for (i = ARR_LEN(delayed) - 1; i >= 0; --i) {
+ ir_node *node = delayed[i].node;
+ if(node == NULL || !is_Phi(node) || get_nodes_block(node) != block)
+ continue;
+
+ DBG((dbg, DBG_START, " spilling delayed phi %+F\n", node));
+ be_spill_phi(senv, node);
+ }
+ DEL_ARR_F(delayed);
+
+ /* Sort start values by first use */
+ qsort(starters, ARR_LEN(starters), sizeof(starters[0]), loc_compare);
+
+ /* Copy the best ones from starters to start workset */
+ ws_count = MIN(ARR_LEN(starters), n_regs);
+ workset_clear(ws);
+ workset_bulk_fill(ws, ws_count, starters);
+
+ /* spill phis (the actual phis not just their values) that are in this block
+ * but not in the start workset */
+ len = ARR_LEN(starters);
+ for (i = ws_count; i < len; ++i) {
+ ir_node *node = starters[i].node;
+ if (! is_Phi(node) || get_nodes_block(node) != block)
+ continue;
+
+ DBG((dbg, DBG_START, " spilling phi %+F\n", node));
+ be_spill_phi(senv, node);
+ }
+
+ DEL_ARR_F(starters);
+
+#if 0
+ /* determine reloaded status of the values: If there's 1 pred block (which
+ * is no backedge) where the value is reloaded then we must set it to
+ * reloaded here. We place spills in all pred where the value was not yet
+ * reloaded to be sure we have a spill on each path */
+ n_pred_worksets = 0;
+ arity = get_irn_arity(block);
+ pred_worksets = alloca(sizeof(pred_worksets[0]) * arity);
+ for(i = 0; i < arity; ++i) {
+ ir_node *pred_block = get_Block_cfgpred_block(block, i);
+ block_info_t *pred_info = get_block_info(pred_block);
+ if(pred_info == NULL)
+ continue;
+
+ pred_worksets[n_pred_worksets] = pred_info->end_workset;
+ ++n_pred_worksets;
+ }
+
+ for(i = 0; i < ws_count; ++i) {
+ loc_t *loc = &ws->vals[i];
+ ir_node *value = loc->node;
+ int reloaded;
+ int n;
+
+ /* phis from this block aren't reloaded */
+ if(get_nodes_block(value) == block) {
+ assert(is_Phi(value));
+ loc->reloaded = value_not_reloaded;
+ continue;
+ }
+
+ /* was the value reloaded on any of the other inputs */
+ reloaded = 0;
+ arity = get_Block_n_cfgpreds(block);
+ for(n = 0; n < n_pred_worksets; ++n) {
+ workset_t *pred_workset = pred_worksets[n];
+ int p_len = workset_get_length(pred_workset);
+ int p;
+
+ for(p = 0; p < p_len; ++p) {
+ loc_t *l = &pred_workset->vals[p];
+ if(l->node == value) {
+ if(l->reloaded) {
+ reloaded = 1;
+ }
+ break;
+ }
+ }
+ if(p >= p_len) {
+ reloaded = 1;
+ break;
+ }
+ }
+ }
+#endif
+}
+
+/**
+ * For the given block @p block, decide for each values
* whether it is used from a register or is reloaded
* before the use.
*/
-static void decide(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);
+static void belady(ir_node *block)
+{
+ workset_t *new_vals;
+ ir_node *irn;
+ int iter;
+ block_info_t *block_info;
+ int i, arity;
+ int has_backedges = 0;
+ //int first = 0;
+ const ir_edge_t *edge;
+
+ /* no need to process a block twice */
+ if(get_block_info(block) != NULL) {
+ return;
+ }
+
+ /* check if all predecessor blocks are processed yet (though for backedges
+ * we have to make an exception as we can't process them first) */
+ arity = get_Block_n_cfgpreds(block);
+ for(i = 0; i < arity; ++i) {
+ ir_node *pred_block = get_Block_cfgpred_block(block, i);
+ block_info_t *pred_info = get_block_info(pred_block);
+
+ if(pred_info == NULL) {
+ /* process predecessor first (it will be in the queue already) */
+ if(!is_backedge(block, i)) {
+ return;
+ }
+ has_backedges = 1;
+ }
+ }
+ (void) has_backedges;
+ if(arity == 0) {
+ workset_clear(ws);
+ } else if(arity == 1) {
+ ir_node *pred_block = get_Block_cfgpred_block(block, 0);
+ block_info_t *pred_info = get_block_info(pred_block);
+
+ assert(pred_info != NULL);
+ workset_copy(ws, pred_info->end_workset);
+ } else {
+ /* we need 2 heuristics here, for the case when all predecessor blocks
+ * are known and when some are backedges (and therefore can't be known
+ * yet) */
+ compute_live_ins(block);
+ }
DBG((dbg, DBG_DECIDE, "\n"));
- DBG((dbg, DBG_DECIDE, "Decide for %+F\n", blk));
+ DBG((dbg, DBG_DECIDE, "Decide for %+F\n", block));
- /* build starting-workset for this block */
- build_start_set(bel, blk);
- blk_info->ws_start = workset_clone(&bel->ob, bel->ws);
- DBG((dbg, DBG_WSETS, "Initial start workset for %+F:\n", blk));
- workset_foreach(blk_info->ws_start, irn)
- DBG((dbg, DBG_WSETS, " %+F\n", irn));
+ block_info = new_block_info();
+ set_block_info(block, block_info);
+
+ DBG((dbg, DBG_WSETS, "Start workset for %+F:\n", block));
+ workset_foreach(ws, irn, iter) {
+ DBG((dbg, DBG_WSETS, " %+F (%u)\n", irn,
+ workset_get_time(ws, iter)));
+ }
+
+ block_info->start_workset = workset_clone(ws);
/* process the block from start to end */
DBG((dbg, DBG_WSETS, "Processing...\n"));
- bel->used = pset_new_ptr(32);
- bel->instr_nr = 0;
- new_vals = new_workset(&bel->ob, bel);
- sched_foreach(blk, irn) {
- assert(workset_get_length(bel->ws) <= bel->n_regs && "Too much values in workset!");
-
-
-#ifdef SINGLE_START_PROJS
- if (is_Phi(irn) ||
- (is_Proj(irn) && blk!=start_blk) ||
- (get_irn_mode(irn) == mode_T && blk==start_blk)) {
- DBG((dbg, DBG_DECIDE, " ...%+F skipped\n", irn));
- continue;
- }
-#else
- /* projs are handled with the tuple value.
- * Phis are no real instr (see insert_starters)
- * instr_nr does not increase */
- if (is_Proj(irn) || is_Phi(irn)) {
- DBG((dbg, DBG_DECIDE, " ...%+F skipped\n", irn));
+ ir_nodeset_init(&used);
+ instr_nr = 0;
+ /* TODO: this leaks (into the obstack)... */
+ new_vals = new_workset();
+
+ sched_foreach(block, irn) {
+ int i, arity;
+ assert(workset_get_length(ws) <= n_regs);
+
+ /* Phis are no real instr (see insert_starters()) */
+ if (is_Phi(irn)) {
continue;
}
-#endif
DBG((dbg, DBG_DECIDE, " ...%+F\n", irn));
/* set instruction in the workset */
- bel->instr = irn;
+ instr = irn;
/* allocate all values _used_ by this instruction */
workset_clear(new_vals);
- workset_bulk_insert(new_vals, get_irn_arity(irn)+1, get_irn_in(irn));
- displace(bel, new_vals, 1);
+ for(i = 0, arity = get_irn_arity(irn); i < arity; ++i) {
+ ir_node *in = get_irn_n(irn, i);
+ if (!arch_irn_consider_in_reg_alloc(arch_env, cls, in))
+ continue;
+
+ /* (note that reloaded_value is irrelevant here) */
+ workset_insert(new_vals, in, 0);
+ }
+ displace(new_vals, 1);
/* allocate all values _defined_ by this instruction */
workset_clear(new_vals);
- if (get_irn_mode(irn) == mode_T) { /* special handling for tuples and projs */
- ir_node *proj;
- for(proj=sched_next(irn); is_Proj(proj); proj=sched_next(proj))
- workset_insert(new_vals, proj);
+ if (get_irn_mode(irn) == mode_T) {
+ const ir_edge_t *edge;
+
+ foreach_out_edge(irn, edge) {
+ ir_node *proj = get_edge_src_irn(edge);
+ if (!arch_irn_consider_in_reg_alloc(arch_env, cls, proj))
+ continue;
+ workset_insert(new_vals, proj, 0);
+ }
} else {
- workset_insert(new_vals, irn);
+ if (!arch_irn_consider_in_reg_alloc(arch_env, cls, irn))
+ continue;
+ workset_insert(new_vals, irn, 0);
}
- displace(bel, new_vals, 0);
+ displace(new_vals, 0);
- bel->instr_nr++;
+ instr_nr++;
}
- del_pset(bel->used);
+ ir_nodeset_destroy(&used);
/* Remember end-workset for this block */
- blk_info->ws_end = workset_clone(&bel->ob, bel->ws);
- DBG((dbg, DBG_WSETS, "Start workset for %+F:\n", blk));
- workset_foreach(blk_info->ws_start, irn)
- DBG((dbg, DBG_WSETS, " %+F\n", irn));
- DBG((dbg, DBG_WSETS, "End workset for %+F:\n", blk));
- workset_foreach(blk_info->ws_end, irn)
- DBG((dbg, DBG_WSETS, " %+F\n", irn));
+ block_info->end_workset = workset_clone(ws);
+ DBG((dbg, DBG_WSETS, "End workset for %+F:\n", block));
+ workset_foreach(ws, irn, iter)
+ DBG((dbg, DBG_WSETS, " %+F (%u)\n", irn,
+ workset_get_time(ws, iter)));
+
+ /* add successor blocks into worklist */
+ foreach_block_succ(block, edge) {
+ ir_node *succ = get_edge_src_irn(edge);
+ pdeq_putr(worklist, succ);
+ }
}
/**
- * 'decide' is block-local and makes assumtions
+ * 'decide' is block-local and makes assumptions
* about the set of live-ins. Thus we must adapt the
* live-outs to the live-ins at each block-border.
*/
-static void fix_block_borders(ir_node *blk, void *env) {
- belady_env_t *bel = env;
- int i, max;
+static void fix_block_borders(ir_node *block, void *data)
+{
+ workset_t *start_workset;
+ int arity;
+ int i;
+ int iter;
+ (void) data;
DBG((dbg, DBG_FIX, "\n"));
- DBG((dbg, DBG_FIX, "Fixing %+F\n", blk));
+ DBG((dbg, DBG_FIX, "Fixing %+F\n", block));
- workset_t *wsb = ((block_info_t *)get_irn_link(blk))->ws_start;
+ start_workset = get_block_info(block)->start_workset;
/* process all pred blocks */
- for (i=0, max=get_irn_arity(blk); i<max; ++i) {
- ir_node *irnb, *irnp, *pred = get_Block_cfgpred_block(blk, i);
- workset_t *wsp = ((block_info_t *)get_irn_link(pred))->ws_end;
+ arity = get_irn_arity(block);
+ for (i = 0; i < arity; ++i) {
+ ir_node *pred = get_Block_cfgpred_block(block, i);
+ workset_t *pred_end_workset = get_block_info(pred)->end_workset;
+ ir_node *node;
DBG((dbg, DBG_FIX, " Pred %+F\n", pred));
- workset_foreach(wsb, irnb) {
- /* if irnb is a phi of the current block we reload
- * the corresponding argument, else irnb itself */
- if(is_Phi(irnb) && blk == get_nodes_block(irnb))
- irnb = get_irn_n(irnb, i);
+ /* spill all values not used anymore */
+ workset_foreach(pred_end_workset, node, iter) {
+ ir_node *n2;
+ int iter2;
+ int found = 0;
+ workset_foreach(start_workset, n2, iter2) {
+ if(n2 == node) {
+ found = 1;
+ break;
+ }
+ /* note that we do not look at phi inputs, becuase the values
+ * will be either live-end and need no spill or
+ * they have other users in which must be somewhere else in the
+ * workset */
+ }
- /* Unknowns are available everywhere */
- if(get_irn_opcode(irnb) == iro_Unknown)
- continue;
+#if 0
+ if(!found && be_is_live_out(lv, pred, node)
+ && !pred_end_workset->vals[iter].reloaded) {
+ ir_node *insert_point
+ = be_get_end_of_block_insertion_point(pred);
+ DBG((dbg, DBG_SPILL, "Spill %+F before %+F\n", node,
+ insert_point));
+ be_add_spill(senv, node, insert_point);
+ }
+#endif
+ }
+
+ /* reload missing values in predecessors */
+ workset_foreach(start_workset, node, iter) {
+ /* if node is a phi of the current block we reload
+ * the corresponding argument, else node itself */
+ if(is_Phi(node) && block == get_nodes_block(node)) {
+ node = get_irn_n(node, i);
- /* check if irnb is in a register at end of pred */
- workset_foreach(wsp, irnp)
- if (irnb == irnp)
- goto next_value;
+ /* we might have unknowns as argument for the phi */
+ if(!arch_irn_consider_in_reg_alloc(arch_env, cls, node))
+ continue;
+ }
- /* irnb is in memory at the end of pred, so we have to reload it */
- DBG((dbg, DBG_FIX, " reload %+F\n", irnb));
- be_add_reload_on_edge(bel->senv, irnb, blk, i);
+ /* check if node is in a register at end of pred */
+ if(workset_contains(pred_end_workset, node))
+ continue;
-next_value:
- /*epsilon statement :)*/;
+ /* node is not in memory at the end of pred -> reload it */
+ DBG((dbg, DBG_FIX, " reload %+F\n", node));
+ DBG((dbg, DBG_SPILL, "Reload %+F before %+F,%d\n", node, block, i));
+ be_add_reload_on_edge(senv, node, block, i, cls, 1);
}
}
}
-/**
- * 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) {
- pset *rlds = (pset *)env;
- if (pset_find_ptr(rlds, irn))
- pset_remove_ptr(rlds, irn);
-}
-
-/**
- * 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) {
- ir_node *irn;
+static void be_spill_belady(be_irg_t *birg, const arch_register_class_t *rcls)
+{
+ ir_graph *irg = be_get_birg_irg(birg);
- irg_walk_graph(irg, rescue_used_reloads, NULL, bel->reloads);
- for(irn = pset_first(bel->reloads); irn; irn = pset_next(bel->reloads)) {
- DBG((dbg, DBG_SPILL, "Removing %+F before %+F in %+F\n", irn, sched_next(irn), get_nodes_block(irn)));
+ be_liveness_assure_sets(be_assure_liveness(birg));
- ir_node *spill = get_irn_n(irn, 0);
+ /* construct control flow loop tree */
+ if(! (get_irg_loopinfo_state(irg) & loopinfo_cf_consistent)) {
+ construct_cf_backedges(irg);
+ }
- /* remove reaload */
- set_irn_n(irn, 0, new_Bad());
- sched_remove(irn);
+ be_clear_links(irg);
- /* if spill not used anymore, remove it too
- * test of regclass is necessary since spill may be a phi-M */
- if (get_irn_n_edges(spill) == 0 && bel->cls == arch_get_irn_reg_class(bel->arch, spill, -1)) {
- set_irn_n(spill, 0, new_Bad());
- sched_remove(spill);
- }
+ /* init belady env */
+ obstack_init(&obst);
+ arch_env = birg->main_env->arch_env;
+ cls = rcls;
+ lv = be_get_birg_liveness(birg);
+ n_regs = cls->n_regs - be_put_ignore_regs(birg, cls, NULL);
+ ws = new_workset();
+ uses = be_begin_uses(irg, lv);
+ loop_ana = be_new_loop_pressure(birg);
+ senv = be_new_spill_env(birg);
+ worklist = new_pdeq();
+
+ pdeq_putr(worklist, get_irg_start_block(irg));
+
+ while(!pdeq_empty(worklist)) {
+ ir_node *block = pdeq_getl(worklist);
+ belady(block);
}
-}
+ /* end block might not be reachable in endless loops */
+ belady(get_irg_end_block(irg));
-void be_spill_belady(const be_main_session_env_t *session, const arch_register_class_t *cls) {
- dbg = firm_dbg_register("ir.be.spillbelady");
- firm_dbg_set_mask(dbg, DEBUG_LVL);
+ del_pdeq(worklist);
- /* init belady env */
- belady_env_t *bel = alloca(sizeof(*bel));
- obstack_init(&bel->ob);
- bel->factory = session->main_env->node_factory;
- bel->arch = session->main_env->arch_env;
- bel->cls = cls;
- bel->n_regs = arch_register_class_n_regs(cls);
- bel->ws = new_workset(&bel->ob, bel);
- bel->uses = be_begin_uses(session->irg, session->main_env->arch_env, cls);
- bel->senv = be_new_spill_env(dbg, session, cls, is_mem_phi, NULL);
- bel->reloads = pset_new_ptr_default();
-
- /* do the work */
- irg_block_walk_graph(session->irg, decide, NULL, bel);
- irg_block_walk_graph(session->irg, fix_block_borders, NULL, bel);
- be_insert_spills_reloads(bel->senv, bel->reloads);
- remove_unused_reloads(session->irg, bel);
+ /* belady was block-local, fix the global flow by adding reloads on the
+ * edges */
+ irg_block_walk_graph(irg, fix_block_borders, NULL, NULL);
+
+ /* Insert spill/reload nodes into the graph and fix usages */
+ be_insert_spills_reloads(senv);
/* clean up */
- del_pset(bel->reloads);
- be_delete_spill_env(bel->senv);
- be_end_uses(bel->uses);
- obstack_free(&bel->ob, NULL);
+ be_delete_spill_env(senv);
+ be_end_uses(uses);
+ be_free_loop_pressure(loop_ana);
+ obstack_free(&obst, NULL);
}
+
+void be_init_spillbelady(void)
+{
+ static be_spiller_t belady_spiller = {
+ be_spill_belady
+ };
+
+ be_register_spiller("belady", &belady_spiller);
+ FIRM_DBG_REGISTER(dbg, "firm.be.spill.belady");
+}
+
+BE_REGISTER_MODULE_CONSTRUCTOR(be_init_spillbelady);
projects / libfirm / blobdiff