X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fbe%2Fbeuses.c;h=56108d3b35882a960c0e9dfcf37bff1ec4e72138;hb=6bb28287b0f135a4dda410e2caa974997a5c6a21;hp=57453e946edb0eaaa024de7292068cd8e7621f4a;hpb=08afd0c691c7f2c385a6ba0d3b3ce7c8891a0978;p=libfirm diff --git a/ir/be/beuses.c b/ir/be/beuses.c index 57453e946..56108d3b3 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. * @@ -22,7 +22,6 @@ * @brief Methods to compute when a value will be used again. * @author Sebastian Hack, Matthias Braun * @date 27.06.2005 - * @version $Id$ */ #include "config.h" @@ -40,6 +39,7 @@ #include "irgraph_t.h" #include "iredges_t.h" #include "irdom_t.h" +#include "util.h" #include "be_t.h" #include "beutil.h" @@ -50,22 +50,30 @@ #include "bearch.h" #include "beuses.h" +#define UNKNOWN_OUTERMOST_LOOP ((unsigned)-1) + 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; +/** + * The "uses" environment. + */ struct be_uses_t { - set *uses; - ir_graph *irg; - const be_lv_t *lv; - unsigned visited_counter; - DEBUG_ONLY(firm_dbg_module_t *dbg;) + 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 = (const be_use_t*)a; @@ -76,14 +84,21 @@ static int cmp_use(const void *a, const void *b, size_t n) } 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) { - unsigned hash = HASH_COMBINE(hash_irn(block), hash_irn(def)); + unsigned hash = hash_combine(hash_irn(block), hash_irn(def)); be_use_t temp; be_use_t* result; @@ -95,26 +110,37 @@ static const be_use_t *get_or_set_use_block(be_uses_t *env, // 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 = (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; @@ -131,20 +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) @@ -177,13 +210,20 @@ 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 *next_use_node; ir_node *node; unsigned timestep; unsigned next_use_step; @@ -194,12 +234,12 @@ static be_next_use_t get_next_use(be_uses_t *env, ir_node *from, from = sched_next(from); } - next_use = NULL; + next_use_node = NULL; next_use_step = INT_MAX; timestep = get_step(from); foreach_out_edge(def, edge) { - ir_node *node = get_edge_src_irn(edge); - unsigned node_step; + unsigned node_step; + node = get_edge_src_irn(edge); if (is_Anchor(node)) continue; @@ -212,16 +252,16 @@ static be_next_use_t get_next_use(be_uses_t *env, ir_node *from, if (node_step < timestep) continue; if (node_step < next_use_step) { - next_use = node; + next_use_node = node; next_use_step = node_step; } } - if (next_use != NULL) { + if (next_use_node != NULL) { be_next_use_t result; result.time = next_use_step - timestep + skip_from_uses; result.outermost_loop = get_loop_depth(get_irn_loop(block)); - result.before = next_use; + result.before = next_use_node; return result; } @@ -241,15 +281,15 @@ static be_next_use_t get_next_use(be_uses_t *env, ir_node *from, } { - 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; @@ -270,10 +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; @@ -306,19 +346,18 @@ 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; } } 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); } /**