X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fbe%2Fbespillbelady.c;h=04cf88710825c6e87ba164a01cbab59eca6f697a;hb=f804d333c7b5459c3c1a6bfc188ecdc54346be73;hp=f915ef419ec9df7f0cb8d592965ed23a90fcd697;hpb=4e284f2fdb54ce9dad76e569d9594f7fec0a04c4;p=libfirm diff --git a/ir/be/bespillbelady.c b/ir/be/bespillbelady.c index f915ef419..04cf88710 100644 --- a/ir/be/bespillbelady.c +++ b/ir/be/bespillbelady.c @@ -3,6 +3,9 @@ * 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" @@ -11,6 +14,7 @@ #ifdef HAVE_ALLOCA_H #include #endif + #ifdef HAVE_MALLOC_H #include #endif @@ -33,24 +37,25 @@ #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 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 */ @@ -60,6 +65,7 @@ typedef struct _belady_env_t { 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 */ spill_env_t *senv; /* see bespill.h */ pset *reloads; /**< all reload nodes placed */ @@ -67,7 +73,7 @@ typedef struct _belady_env_t { 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 */ }; @@ -88,6 +94,9 @@ static INLINE workset_t *new_workset(struct obstack *ob, belady_env_t *bel) { 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]); @@ -96,6 +105,24 @@ static INLINE workset_t *workset_clone(struct obstack *ob, workset_t *ws) { 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. @@ -152,12 +179,6 @@ no_insert: } } -/** - * 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 */ @@ -199,34 +220,40 @@ 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)); - sws = ((block_info_t *)get_irn_link(blk))->ws_start; + 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); } /** * 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; @@ -235,18 +262,43 @@ static void build_start_set(belady_env_t *bel, ir_node *blk) { 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; icls, 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); + } + } obstack_free(&ob, NULL); } @@ -330,24 +382,21 @@ static void displace(belady_env_t *bel, workset_t *new_vals, int is_usage) { * 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 */ @@ -416,9 +465,9 @@ static void decide(ir_node *blk, void *env) { * 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; - workset_t *wsb; DBG((dbg, DBG_FIX, "\n")); DBG((dbg, DBG_FIX, "Fixing %+F\n", blk)); @@ -467,6 +516,26 @@ static void rescue_used_reloads(ir_node *irn, void *env) { 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, *spill; + + 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?"); + + 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 @@ -494,27 +563,33 @@ static void remove_unused_reloads(ir_graph *irg, belady_env_t *bel) { } } -void be_spill_belady(const be_main_session_env_t *session, const arch_register_class_t *cls) { +void be_spill_belady(const be_chordal_env_t *chordal_env) { belady_env_t bel; + dbg = firm_dbg_register("ir.be.spillbelady"); - firm_dbg_set_mask(dbg, DEBUG_LVL); /* init belady env */ 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.arch = chordal_env->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->main_env->arch_env, bel.cls); + bel.senv = be_new_spill_env(dbg, chordal_env, is_mem_phi, NULL); 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 */ - irg_block_walk_graph(session->irg, decide, NULL, &bel); - irg_block_walk_graph(session->irg, fix_block_borders, 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(session->irg, &bel); + remove_unused_reloads(chordal_env->irg, &bel); + remove_copies(&bel); + + /* clean up */ del_pset(bel.reloads);