X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fbe%2Fbeuses.c;h=497c136055ec8b202247a5e540e92f954daa41cc;hb=6f068af98daa4725d60e5d23a8f98ec2841cfa44;hp=5b9375f09140417d92c3b66587152e4f828aadda;hpb=7c36344d22a7c306a4e216f135c974bdb9f6b943;p=libfirm diff --git a/ir/be/beuses.c b/ir/be/beuses.c index 5b9375f09..497c13605 100644 --- a/ir/be/beuses.c +++ b/ir/be/beuses.c @@ -1,5 +1,5 @@ /* - * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved. + * Copyright (C) 1995-2011 University of Karlsruhe. All right reserved. * * This file is part of libFirm. * @@ -50,37 +50,50 @@ #include "bearch.h" #include "beuses.h" -#define SCAN_INTERBLOCK_USES +#define UNKNOWN_OUTERMOST_LOOP ((unsigned)-1) -typedef struct _be_use_t { +typedef struct be_use_t { const ir_node *block; const ir_node *node; - int outermost_loop; + unsigned outermost_loop; unsigned next_use; - unsigned visited; + ir_visited_t visited; } be_use_t; -struct _be_uses_t { - set *uses; - ir_graph *irg; - const be_lv_t *lv; - unsigned visited_counter; - DEBUG_ONLY(firm_dbg_module_t *dbg;) +/** + * The "uses" environment. + */ +struct be_uses_t { + set *uses; /**< cache: contains all computed uses so far. */ + ir_graph *irg; /**< the graph for this environment. */ + const be_lv_t *lv; /**< the liveness for the graph. */ + ir_visited_t visited_counter; /**< current search counter. */ + DEBUG_ONLY(firm_dbg_module_t *dbg; /**< debug module for debug messages. */) }; +/** + * Set-compare two uses. + */ static int cmp_use(const void *a, const void *b, size_t n) { - const be_use_t *p = a; - const be_use_t *q = b; + const be_use_t *p = (const be_use_t*)a; + const be_use_t *q = (const be_use_t*)b; (void) n; return !(p->block == q->block && p->node == q->node); } static be_next_use_t get_next_use(be_uses_t *env, ir_node *from, - unsigned from_step, const ir_node *def, - int skip_from_uses); + const ir_node *def, int skip_from_uses); +/** + * Return the use for the given definition in the given block if exists, + * else create it. + * + * @param env the uses environment + * @param block the block we search the use in + * @param def the definition of the value we are searching + */ static const be_use_t *get_or_set_use_block(be_uses_t *env, const ir_node *block, const ir_node *def) @@ -91,32 +104,43 @@ static const be_use_t *get_or_set_use_block(be_uses_t *env, temp.block = block; temp.node = def; - result = set_find(env->uses, &temp, sizeof(temp), hash); + result = (be_use_t*)set_find(env->uses, &temp, sizeof(temp), hash); if (result == NULL) { // insert templ first as we might end in a loop in the get_next_use // call otherwise temp.next_use = USES_INFINITY; - temp.outermost_loop = -1; + temp.outermost_loop = UNKNOWN_OUTERMOST_LOOP; temp.visited = 0; - result = set_insert(env->uses, &temp, sizeof(temp), hash); + result = (be_use_t*)set_insert(env->uses, &temp, sizeof(temp), hash); } - if (result->outermost_loop < 0 && result->visited < env->visited_counter) { + if (result->outermost_loop == UNKNOWN_OUTERMOST_LOOP && result->visited < env->visited_counter) { be_next_use_t next_use; result->visited = env->visited_counter; - next_use = get_next_use(env, sched_first(block), 0, def, 0); - if (next_use.outermost_loop >= 0) { + next_use = get_next_use(env, sched_first(block), def, 0); + if (next_use.outermost_loop != UNKNOWN_OUTERMOST_LOOP) { result->next_use = next_use.time; result->outermost_loop = next_use.outermost_loop; - DBG((env->dbg, LEVEL_5, "Setting nextuse of %+F in block %+F to %u (outermostloop %d)\n", def, block, result->next_use, result->outermost_loop)); + DBG((env->dbg, LEVEL_5, "Setting nextuse of %+F in block %+F to %u (outermostloop %d)\n", + def, block, result->next_use, result->outermost_loop)); } } return result; } +/** + * Check if a value of the given definition is used in the given block + * as a Phi argument. + * + * @param block the block to check + * @param def the definition of the value + * + * @return non-zero if the value is used in the given block as a Phi argument + * in one of its successor blocks. + */ static int be_is_phi_argument(const ir_node *block, const ir_node *def) { ir_node *node; @@ -133,20 +157,27 @@ static int be_is_phi_argument(const ir_node *block, const ir_node *def) succ_block = get_first_block_succ(block); arity = get_Block_n_cfgpreds(succ_block); - if (arity <= 1) + if (arity <= 1) { + /* no Phis in the successor */ return 0; + } + /* find the index of block in its successor */ for (i = 0; i < arity; ++i) { if (get_Block_cfgpred_block(succ_block, i) == block) break; } assert(i < arity); + /* iterate over the Phi nodes in the successor and check if def is + * one of its arguments */ sched_foreach(succ_block, node) { ir_node *arg; - if (!is_Phi(node)) + if (!is_Phi(node)) { + /* found first non-Phi node, we can stop the search here */ break; + } arg = get_irn_n(node, i); if (arg == def) @@ -156,16 +187,41 @@ static int be_is_phi_argument(const ir_node *block, const ir_node *def) return 0; } +/** + * Retrieve the scheduled index (the "step") of this node in its + * block. + * + * @param node the node + */ static inline unsigned get_step(const ir_node *node) { - return PTR_TO_INT(get_irn_link(node)); + return (unsigned)PTR_TO_INT(get_irn_link(node)); } +/** + * Set the scheduled index (the "step") of this node in its + * block. + * + * @param node the node + * @param step the scheduled index of the node + */ +static inline void set_step(ir_node *node, unsigned step) +{ + set_irn_link(node, INT_TO_PTR(step)); +} + +/** + * Find the next use of a value defined by def, starting at node from. + * + * @param env the uses environment + * @param from the node at which we should start the search + * @param def the definition of the value + * @param skip_from_uses if non-zero, ignore from uses + */ static be_next_use_t get_next_use(be_uses_t *env, ir_node *from, - unsigned from_step, const ir_node *def, - int skip_from_uses) + const ir_node *def, int skip_from_uses) { - unsigned step = from_step; + unsigned step; ir_node *block = get_nodes_block(from); ir_node *next_use; ir_node *node; @@ -173,7 +229,6 @@ static be_next_use_t get_next_use(be_uses_t *env, ir_node *from, unsigned next_use_step; const ir_edge_t *edge; -#if 1 assert(skip_from_uses == 0 || skip_from_uses == 1); if (skip_from_uses) { from = sched_next(from); @@ -213,48 +268,6 @@ static be_next_use_t get_next_use(be_uses_t *env, ir_node *from, node = sched_last(block); step = get_step(node) + 1 + timestep + skip_from_uses; -#else - if (skip_from_uses) { - from = sched_next(from); - ++step; - } - - sched_foreach_from(from, node) { - int i, arity; - - if (is_Phi(node)) { - step++; - continue; - } - - arity = get_irn_arity(node); - for (i = 0; i < arity; ++i) { - const ir_node *operand = get_irn_n(node, i); - - if (operand == def) { - be_next_use_t result; - - DBG((env->dbg, LEVEL_3, "found use of %+F at %+F\n", operand, node)); - - /** - * Spills/Reloads are a special case, they're not really a - * usage of a value, continue searching - */ - if (be_is_Spill(node) || be_is_Reload(node)) { - return be_get_next_use(env, node, step, node, 1); - } - - result.time = step; - result.outermost_loop = get_loop_depth(get_irn_loop(block)); - result.before = node; - return result; - } - } - - step++; - } -#endif - if (be_is_phi_argument(block, def)) { // TODO we really should continue searching the uses of the phi, // as a phi isn't a real use that implies a reload (because we could @@ -267,17 +280,16 @@ static be_next_use_t get_next_use(be_uses_t *env, ir_node *from, return result; } -#ifdef SCAN_INTERBLOCK_USES { - unsigned next_use = USES_INFINITY; - int outermost_loop; + unsigned next_use = USES_INFINITY; + unsigned outermost_loop; be_next_use_t result; - ir_loop *loop = get_irn_loop(block); - int loopdepth = get_loop_depth(loop); - int found_visited = 0; - int found_use = 0; - ir_graph *irg = get_irn_irg(block); - ir_node *startblock = get_irg_start_block(irg); + ir_loop *loop = get_irn_loop(block); + unsigned loopdepth = get_loop_depth(loop); + int found_visited = 0; + int found_use = 0; + ir_graph *irg = get_irn_irg(block); + ir_node *startblock = get_irg_start_block(irg); result.before = NULL; outermost_loop = loopdepth; @@ -298,10 +310,10 @@ static be_next_use_t get_next_use(be_uses_t *env, ir_node *from, } use = get_or_set_use_block(env, succ_block, def); - DBG((env->dbg, LEVEL_5, "Found %u (loopdepth %d) (we're in block %+F)\n", use->next_use, + DBG((env->dbg, LEVEL_5, "Found %u (loopdepth %u) (we're in block %+F)\n", use->next_use, use->outermost_loop, block)); if (USES_IS_INFINITE(use->next_use)) { - if (use->outermost_loop < 0) { + if (use->outermost_loop == UNKNOWN_OUTERMOST_LOOP) { found_visited = 1; } continue; @@ -334,24 +346,27 @@ static be_next_use_t get_next_use(be_uses_t *env, ir_node *from, if (!found_use && found_visited) { // the current result is correct for the current search, but isn't // generally correct, so mark it - result.outermost_loop = -1; + result.outermost_loop = UNKNOWN_OUTERMOST_LOOP; } - DBG((env->dbg, LEVEL_5, "Result: %d (outerloop: %d)\n", result.time, result.outermost_loop)); + DBG((env->dbg, LEVEL_5, "Result: %d (outerloop: %u)\n", result.time, result.outermost_loop)); return result; } -#else - return USES_INFINITY; -#endif } be_next_use_t be_get_next_use(be_uses_t *env, ir_node *from, - unsigned from_step, const ir_node *def, - int skip_from_uses) + const ir_node *def, int skip_from_uses) { - env->visited_counter++; - return get_next_use(env, from, from_step, def, skip_from_uses); + ++env->visited_counter; + return get_next_use(env, from, def, skip_from_uses); } +/** + * Pre-block walker, set the step number for every scheduled node + * in increasing order. + * + * After this, two scheduled nodes can be easily compared for the + * "scheduled earlier in block" property. + */ static void set_sched_step_walker(ir_node *block, void *data) { ir_node *node; @@ -359,7 +374,7 @@ static void set_sched_step_walker(ir_node *block, void *data) (void) data; sched_foreach(block, node) { - set_irn_link(node, INT_TO_PTR(step)); + set_step(node, step); if (is_Phi(node)) continue; ++step;