X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fbe%2Fbespillbelady.c;h=a5d431bd312fe4a04878f5d7db1cdb92c9d8bbbe;hb=5af4cb6fd26054ef16c8da79d534abacb2a32c6e;hp=ed734c0390c631a5a06fa0f8a9629db80d6af569;hpb=712cea35fe399ae20e3a33eb9bf81360b5000cf3;p=libfirm diff --git a/ir/be/bespillbelady.c b/ir/be/bespillbelady.c index ed734c039..a5d431bd3 100644 --- a/ir/be/bespillbelady.c +++ b/ir/be/bespillbelady.c @@ -1,121 +1,159 @@ -/** - * Author: Daniel Grund - * Date: 20.09.2005 - * Copyright: (c) Universitaet Karlsruhe - * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE. +/* + * Copyright (C) 1995-2008 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. + */ + +/** + * @file + * @brief Beladys spillalgorithm. + * @author Daniel Grund, Matthias Braun + * @date 20.09.2005 + * @version $Id$ */ #ifdef HAVE_CONFIG_H #include "config.h" #endif -#ifdef HAVE_ALLOCA_H -#include -#endif - -#ifdef HAVE_MALLOC_H -#include -#endif - #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" - -#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 DEBUG_LVL 0 //(DBG_START | DBG_DECIDE | DBG_WSETS | DBG_FIX | DBG_SPILL) +#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;) -#define MIN(a,b) (((a)<(b))?(a):(b)) - -typedef struct _workset_t workset_t; - -typedef struct _belady_env_t { - struct obstack ob; - 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 */ - pset *copies; /**< holds all copies placed due to phi-spilling */ +/* 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 - spill_env_t *senv; /* see bespill.h */ - pset *reloads; /**< all reload nodes placed */ -} belady_env_t; +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; -struct _workset_t { - belady_env_t *bel; - int len; /**< current length */ - loc_t vals[1]; /**< inlined array of the values/distances in this working set */ -}; +/** + * 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_printf("%+F %d\n", w->vals[i].irn, w->vals[i].time); + 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; } /** - * Alloc a new instance on obstack and make it equal to @param ws + * Alloc a new instance on obstack and make it equal to @param workset */ -static INLINE workset_t *workset_clone(struct obstack *ob, workset_t *ws) { +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; } /** - * Do NOT alloc anything. Make @param tgt equal to @param src. - * returns @param tgt for convinience + * Copy workset @param src to @param tgt */ -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; +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); } /** @@ -123,87 +161,74 @@ static INLINE workset_t *workset_copy(workset_t *tgt, workset_t *src) { * @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])); - +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 the value @p val into the workset, iff it is not * already contained. The workset must not be full. */ -static INLINE void workset_insert(workset_t *ws, ir_node *val) { - int i; +static void workset_insert(workset_t *workset, ir_node *val, int reloaded) +{ + loc_t *loc; + 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; - } + assert(arch_irn_consider_in_reg_alloc(arch_env, cls, val)); /* check if val is already contained */ - for(i=0; ilen; ++i) - if (ws->vals[i].irn == val) + for (i = 0; i < workset->len; ++i) { + loc = &workset->vals[i]; + if (loc->node == val) { + if(!loc->reloaded) { + loc->reloaded = reloaded; + } return; - - /* insert val */ - assert(ws->len < ws->bel->n_regs && "Workset already full!"); - ws->vals[ws->len++].irn = val; -} - -/** - * Inserts all values in array @p vals of length @p cnt - * into the workset. There must be enough space for the - * entries. - */ -static INLINE void workset_bulk_insert(workset_t *ws, int cnt, ir_node **vals) { - int i, o; - - for(o=0; obel->arch, val, -1) != ws->bel->cls) { - DBG((dbg, DBG_TRACE, "Wrong reg class\n")); - goto no_insert; } - - /* check if val is already contained */ - for(i=0; ilen; ++i) - if (ws->vals[i].irn == val) { - DBG((dbg, DBG_TRACE, "Already contained\n")); - goto no_insert; - } - - /* 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 :)*/; } + + /* 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; ilen; ++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; ilen; ++i) - if (ws->vals[i].irn == val) + + for(i=0; ilen; ++i) { + if (ws->vals[i].node == val) return 1; + } + return 0; } @@ -214,55 +239,60 @@ static INLINE int workset_contains(const workset_t *ws, const ir_node *val) { * @p i An integer for internal use */ #define workset_foreach(ws, v, i) for(i=0; \ - v=(i < ws->len) ? ws->vals[i].irn : NULL, i < ws->len; \ + 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 *ws_start, *ws_end; +typedef struct _block_info_t +{ + workset_t *start_workset; + workset_t *end_workset; } block_info_t; -static INLINE void *new_block_info(struct obstack *ob) { - block_info_t *res = obstack_alloc(ob, sizeof(*res)); - res->ws_start = NULL; - res->ws_end = NULL; +static void *new_block_info(void) +{ + block_info_t *res = obstack_alloc(&obst, sizeof(res[0])); + memset(res, 0, sizeof(res[0])); return res; } -#define get_block_info(blk) ((block_info_t *)get_irn_link(blk)) -#define set_block_info(blk, info) set_irn_link(blk, info) - -static int is_mem_phi(const ir_node *irn, void *data) { - workset_t *sws; - ir_node *blk = get_nodes_block(irn); - - DBG((dbg, DBG_SPILL, "Is %+F a mem-phi?\n", irn)); - sws = get_block_info(blk)->ws_start; - DBG((dbg, DBG_SPILL, " %d\n", !workset_contains(sws, irn))); - return !workset_contains(sws, irn); -} +#define get_block_info(block) ((block_info_t *)get_irn_link(block)) +#define set_block_info(block, info) set_irn_link(block, info) /** - * @return The distance to the next use - * Or 0 if irn is an ignore node + * @return The distance to the next use or 0 if irn has dont_spill flag set */ - -static INLINE unsigned get_distance(belady_env_t *bel, const ir_node *from, unsigned from_step, const ir_node *def, int skip_from_uses) +static INLINE unsigned get_distance(ir_node *from, unsigned from_step, + const ir_node *def, int skip_from_uses) { - arch_irn_flags_t fl = arch_irn_get_flags(bel->arch, def); - unsigned dist = be_get_next_use(bel->uses, from, from_step, def, skip_from_uses); + be_next_use_t use; + int flags = arch_irn_get_flags(arch_env, def); + unsigned costs; + unsigned time; + + assert(! (flags & arch_irn_flags_ignore)); - if(!USES_IS_INIFINITE(dist) && (fl & (arch_irn_flags_ignore | arch_irn_flags_dont_spill)) != 0) + use = be_get_next_use(uses, from, from_step, def, skip_from_uses); + if(USES_IS_INFINITE(use.time)) + return USES_INFINITY; + + /* We have to keep nonspillable nodes in the workingset */ + if(flags & arch_irn_flags_dont_spill) return 0; - return dist; + 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; } /** @@ -274,256 +304,445 @@ static INLINE unsigned get_distance(belady_env_t *bel, const ir_node *from, unsi * @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, iter; - 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, iter) { /* mark value as used */ if (is_usage) - pset_insert_ptr(bel->used, 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)); + ir_nodeset_insert(&used, val); + + if (! workset_contains(ws, val)) { + DB((dbg, DBG_DECIDE, " insert %+F\n", val)); + if (is_usage) { + DB((dbg, DBG_SPILL, "Reload %+F before %+F\n", val, instr)); + be_add_reload(senv, val, instr, cls, 1); + } + } else { + DB((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; ilen; ++i) - workset_set_time(ws, i, get_distance(bel, 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; + + DB((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; ilen; ++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 = get_block_info(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; + + DB((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 (!is_Phi(val) && ! ir_nodeset_contains(&used, val)) { + workset_remove(ws_start, val); + DB((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 - */ - workset_bulk_insert(bel->ws, demand, to_insert); + /* 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); + } } -static void belady(ir_node *blk, void *env); +/** 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; + DB((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; + DB((dbg, DBG_START, " %+F not taken (dead)\n", node)); + if(is_Phi(node)) { + be_spill_phi(senv, node); + } + return loc; + } + + loc.time = next_use.time; + + if(next_use.outermost_loop >= get_loop_depth(loop)) { + DB((dbg, DBG_START, " %+F taken (%u, loop %d)\n", node, loc.time, next_use.outermost_loop)); + } else { + loc.time = USES_PENDING; + DB((dbg, DBG_START, " %+F delayed (outerloopdepth %d < loopdetph %d)\n", node, next_use.outermost_loop, get_loop_depth(loop))); + } + return loc; +} /** - * 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. - * 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. + * 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 block_info_t *compute_block_start_info(ir_node *blk, void *env) { - belady_env_t *bel = env; - ir_node *irn, *first; - irn_live_t *li; - int i, count, ws_count; - loc_t loc, *starters; - ir_graph *irg = get_irn_irg(blk); - struct obstack ob; - block_info_t *res = get_block_info(blk); - - /* Have we seen this block before? */ - if (res) - return res; - - /* Create the block info for this block. */ - res = new_block_info(&bel->ob); - set_block_info(blk, res); - - - /* Get all values living at the block start sorted by next use*/ - obstack_init(&ob); - - 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 = get_distance(bel, first, 0, irn, 0); - obstack_grow(&ob, &loc, sizeof(loc)); - DBG((dbg, DBG_START, " %+F:\n", irn)); - count++; - } else +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); + + DB((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; - 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 = get_distance(bel, first, 0, li->irn, 0); - obstack_grow(&ob, &loc, sizeof(loc)); - DBG((dbg, DBG_START, " %+F:\n", irn)); - count++; + 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); } + } - starters = obstack_finish(&ob); - qsort(starters, count, sizeof(starters[0]), loc_compare); + /* 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 we have only one predecessor, we want the start_set of blk to be the end_set of pred */ - if (get_Block_n_cfgpreds(blk) == 1 && blk != get_irg_start_block(get_irn_irg(blk))) { - ir_node *pred_blk = get_Block_cfgpred_block(blk, 0); - block_info_t *pred_info = get_block_info(pred_blk); + 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); + } + } - /* if pred block has not been processed yet, do it now */ - if (! pred_info) { - belady(pred_blk, bel); - pred_info = get_block_info(pred_blk); + 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) { + DB((dbg, DBG_START, " delayed %+F taken\n", delayed[i].node)); + ARR_APP1(loc_t, starters, delayed[i]); + delayed[i].node = NULL; } + } - /* 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); + /* 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; - } else + DB((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; - /* 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); - workset_bulk_fill(res->ws_start, ws_count, starters); + DB((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; - /* 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. - * After spilling these copies get deleted. */ - for (i=workset_get_length(res->ws_start); iend_workset; + ++n_pred_worksets; + } - irn = starters[i].irn; - if (!is_Phi(irn) || get_nodes_block(irn) != blk) - continue; + for(i = 0; i < ws_count; ++i) { + loc_t *loc = &ws->vals[i]; + ir_node *value = loc->node; + int reloaded; + int n; - DBG((dbg, DBG_START, "For %+F:\n", irn)); + /* phis from this block aren't reloaded */ + if(get_nodes_block(value) == block) { + assert(is_Phi(value)); + loc->reloaded = value_not_reloaded; + continue; + } - for (max=get_irn_arity(irn), o=0; ocls, 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)); - sched_add_before(pred_block, cpy); - set_irn_n(irn, o, cpy); + /* 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; + } } } - - obstack_free(&ob, NULL); - return res; +#endif } - /** - * For the given block @p blk, decide for each values + * 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 belady(ir_node *blk, void *env) { - belady_env_t *bel = env; - workset_t *new_vals; - ir_node *irn; - int iter; - block_info_t *blk_info; - - /* Don't do a block twice */ - if (get_block_info(blk)) +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); + } + + DB((dbg, DBG_DECIDE, "\n")); + DB((dbg, DBG_DECIDE, "Decide for %+F\n", block)); - /* get the starting workset for this block */ - blk_info = compute_block_start_info(blk, bel); + block_info = new_block_info(); + set_block_info(block, block_info); - DBG((dbg, DBG_DECIDE, "\n")); - DBG((dbg, DBG_DECIDE, "Decide for %+F\n", blk)); + DB((dbg, DBG_WSETS, "Start workset for %+F:\n", block)); + workset_foreach(ws, irn, iter) { + DB((dbg, DBG_WSETS, " %+F (%u)\n", irn, + workset_get_time(ws, iter))); + } - workset_copy(bel->ws, blk_info->ws_start); - DBG((dbg, DBG_WSETS, "Start workset for %+F:\n", blk)); - workset_foreach(bel->ws, irn, iter) - DBG((dbg, DBG_WSETS, " %+F\n", irn)); + 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!"); - - - /* 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)); + DB((dbg, DBG_WSETS, "Processing...\n")); + 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; } - DBG((dbg, DBG_DECIDE, " ...%+F\n", irn)); + DB((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, "End workset for %+F:\n", blk)); - workset_foreach(blk_info->ws_end, irn, iter) - DBG((dbg, DBG_WSETS, " %+F\n", irn)); + block_info->end_workset = workset_clone(ws); + DB((dbg, DBG_WSETS, "End workset for %+F:\n", block)); + workset_foreach(ws, irn, iter) + DB((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); + } } /** @@ -531,137 +750,138 @@ static void belady(ir_node *blk, void *env) { * 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) { - workset_t *wsb; - belady_env_t *bel = env; - int i, max, iter, iter2; +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)); + DB((dbg, DBG_FIX, "\n")); + DB((dbg, DBG_FIX, "Fixing %+F\n", block)); - wsb = get_block_info(blk)->ws_start; + start_workset = get_block_info(block)->start_workset; /* process all pred blocks */ - for (i=0, max=get_irn_arity(blk); iws_end; - - DBG((dbg, DBG_FIX, " Pred %+F\n", pred)); + 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; + + DB((dbg, DBG_FIX, " Pred %+F\n", pred)); + + /* 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 */ + } - workset_foreach(wsb, irnb, iter) { - /* 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); +#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); + DB((dbg, DBG_SPILL, "Spill %+F before %+F\n", node, + insert_point)); + be_add_spill(senv, node, insert_point); + } +#endif + } - /* Unknowns are available everywhere */ - if(get_irn_opcode(irnb) == iro_Unknown) - continue; + /* 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, iter2) - 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 */ + DB((dbg, DBG_FIX, " reload %+F\n", node)); + DB((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); -} - -/** - * Removes all copies introduced for phi-spills - */ -static void remove_copies(belady_env_t *bel) { - ir_node *irn; - - for (irn = pset_first(bel->copies); irn; irn = pset_next(bel->copies)) { - ir_node *src, *user; - - assert(be_is_Copy(irn)); - assert(get_irn_n_edges(irn) == 1 && "This is not a copy introduced in 'compute_block_start_info()'. Who created it?"); +static void be_spill_belady(be_irg_t *birg, const arch_register_class_t *rcls) +{ + ir_graph *irg = be_get_birg_irg(birg); - user = get_irn_edge(get_irn_irg(irn), irn, 0)->src; + be_liveness_assure_sets(be_assure_liveness(birg)); - src = be_get_Copy_op(irn); - set_irn_n(user, 0, src); + /* construct control flow loop tree */ + if(! (get_irg_loopinfo_state(irg) & loopinfo_cf_consistent)) { + construct_cf_backedges(irg); } -} -/** - * 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; - - irg_walk_graph(irg, rescue_used_reloads, 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))); - - if (be_is_Reload(irn)) - spill = get_irn_n(irn, be_pos_Reload_mem); - - /* remove reload */ - set_irn_n(irn, 0, new_Bad()); - sched_remove(irn); - - if (be_is_Reload(irn)) { - /* 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); - } - } + be_clear_links(irg); + + /* 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_chordal_env_t *chordal_env) { - belady_env_t bel; + del_pdeq(worklist); - FIRM_DBG_REGISTER(dbg, "ir.be.spillbelady"); + /* belady was block-local, fix the global flow by adding reloads on the + * edges */ + irg_block_walk_graph(irg, fix_block_borders, NULL, NULL); - /* init belady env */ - obstack_init(&bel.ob); - bel.arch = chordal_env->birg->main_env->arch_env; - bel.cls = chordal_env->cls; - bel.n_regs = arch_register_class_n_regs(bel.cls); - bel.ws = new_workset(&bel.ob, &bel); - bel.uses = be_begin_uses(chordal_env->irg, chordal_env->birg->main_env->arch_env, bel.cls); - bel.senv = be_new_spill_env(chordal_env, is_mem_phi, NULL); - DEBUG_ONLY(be_set_spill_env_dbg_module(bel.senv, dbg);) - bel.reloads = pset_new_ptr_default(); - bel.copies = pset_new_ptr_default(); - - DBG((dbg, LEVEL_1, "running on register class: %s\n", bel.cls->name)); - - /* do the work */ - be_clear_links(chordal_env->irg); - irg_block_walk_graph(chordal_env->irg, NULL, belady, &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(&bel); + /* 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);