X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fana%2Fstructure.c;h=356225f2c63a5a2469949e3512d6e709edb75d58;hb=0f234e2d94155d13c0e4727871125beda0eaa66d;hp=08b2bef2fe220408e5b84fe6c62f075815da6766;hpb=b5d7f94e82eff9d852eaa2b3b181de4570311f78;p=libfirm diff --git a/ir/ana/structure.c b/ir/ana/structure.c index 08b2bef2f..356225f2c 100644 --- a/ir/ana/structure.c +++ b/ir/ana/structure.c @@ -1,17 +1,30 @@ /* - * Project: libFIRM - * File name: ir/ana/structure.c - * Purpose: Structure Analysis - * Author: Michael Beck - * Modified by: - * Created: 5.4.2007 - * CVS-ID: $Id: $ - * Copyright: (c) 2007 Universität Karlsruhe - * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE. - */ -#ifdef HAVE_CONFIG_H + * 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 Structure Analysis + * @author Michael Beck + * @date 5.4.2007 + * @version $Id$ + */ #include "config.h" -#endif #include "firm_common.h" #include "irnode_t.h" @@ -21,7 +34,7 @@ #include "irtools.h" #include "irgwalk.h" #include "array.h" -#include "irphase_t.h" +#include "irdump.h" #include "debug.h" @@ -36,17 +49,19 @@ struct ir_reg_tree { /* A region. */ struct ir_region { - firm_kind kind; /**< Must be k_ir_region. */ - ir_region_kind type; /**< The type of this region. */ - ir_region *parent; /**< points to the parent. */ - ir_reg_or_blk *parts; /**< The list of all region parts. */ - ir_region **pred; /**< The predecessor (control flow) regions of this region. */ - ir_region **succ; /**< The successor (control flow) regions of this region. */ - unsigned prenum; /**< DFS pre-oder number */ - unsigned postnum; /**< DFS post-oder number */ - void *link; /**< A link field. */ - unsigned long nr; /**< for debugging */ - char visited; /**< The visited flag. */ + firm_kind kind; /**< Must be k_ir_region. */ + ir_region_kind type; /**< The type of this region. */ + ir_region *parent; /**< points to the parent. */ + ir_reg_or_blk *parts; /**< The list of all region parts. */ + ir_region **pred; /**< The predecessor (control flow) regions of this region. */ + ir_region **succ; /**< The successor (control flow) regions of this region. */ + unsigned prenum; /**< DFS pre-oder number */ + unsigned postnum; /**< DFS post-oder number */ + void *link; /**< A link field. */ + unsigned long nr; /**< for debugging */ + unsigned visited:1; /**< The visited flag. */ + unsigned exit:1; /**< If set, the parent region can be left by this node. */ + unsigned enter:1; /**< If set, the parent region can be entered by this node. */ }; /* A helper type for unioning blocks and regions. */ @@ -57,7 +72,7 @@ union ir_reg_or_blk { }; /* The debug handle. */ -DEBUG_ONLY(firm_dbg_module_t *dbg;) +DEBUG_ONLY(static firm_dbg_module_t *dbg;) /** * Returns the link of a region. @@ -99,7 +114,7 @@ ir_region *get_irn_region(ir_node *n) { } /** - * Return non-if a given firm thing is a region. + * Return non-zero if a given firm thing is a region. */ int is_region(const void *thing) { const firm_kind *kind = thing; @@ -107,7 +122,7 @@ int is_region(const void *thing) { } /** - * Return the number of predecessors in a region. + * Return the number of predecessors of a region. */ int get_region_n_preds(const ir_region *reg) { return ARR_LEN(reg->pred); @@ -156,13 +171,13 @@ void set_region_succ(ir_region *reg, int pos, ir_region *n) { /** Walker environment. */ typedef struct walk_env { - struct obstack *obst; /**< an obstack to allocate from. */ + struct obstack *obst; /**< An obstack to allocate from. */ ir_region **post; /**< The list of all currently existent top regions. */ - unsigned l_post; /**< length of the allocated regions array. */ + unsigned l_post; /**< The length of the allocated regions array. */ unsigned premax; /**< maximum pre counter */ unsigned postmax; /**< maximum post counter */ - ir_node *start_block; /**< the start block of the graph. */ - ir_node *end_block; /**< the end block of the graph. */ + ir_node *start_block; /**< The start block of the graph. */ + ir_node *end_block; /**< The end block of the graph. */ } walk_env; /** @@ -213,13 +228,15 @@ static void wrap_BasicBlocks(ir_node *block, void *ctx) { ir_region *reg; /* Allocate a Block wrapper */ - reg = obstack_alloc(env->obst, sizeof(*reg)); + reg = OALLOC(env->obst, ir_region); reg->kind = k_ir_region; reg->type = ir_rk_BasicBlock; reg->parent = NULL; reg->prenum = 0; reg->postnum = 0; reg->visited = 0; + reg->exit = 0; + reg->enter = 0; reg->link = NULL; reg->nr = get_irn_node_nr(block); reg->parts = NEW_ARR_D(ir_reg_or_blk, env->obst, 1); @@ -231,7 +248,7 @@ static void wrap_BasicBlocks(ir_node *block, void *ctx) { } /* wrap_BasicBlocks */ /** - * Create the pred and succ edges for Block wrapper. + * Post-walker: Create the pred and succ edges for Block wrapper. * Kill edges to the Start and End blocks. */ static void update_BasicBlock_regions(ir_node *blk, void *ctx) { @@ -240,7 +257,7 @@ static void update_BasicBlock_regions(ir_node *blk, void *ctx) { int i, j, len; if (blk == env->start_block) { - /* handle Firm's self loop */ + /* handle Firm's self loop: Start block has no predecessors */ reg->pred = NEW_ARR_D(ir_region *, env->obst, 0); } else { len = get_Block_n_cfgpreds(blk); @@ -261,16 +278,18 @@ static void update_BasicBlock_regions(ir_node *blk, void *ctx) { ARR_SHRINKLEN(reg->succ, j); } /* update_BasicBlock_regions */ -/** Allocate a new region of a obstack */ +/** Allocate a new region on an obstack */ #define ALLOC_REG(obst, reg, tp) \ do { \ - (reg) = obstack_alloc((obst), sizeof(*(reg))); \ + (reg) = OALLOC((obst), ir_region); \ (reg)->kind = k_ir_region; \ (reg)->type = tp; \ (reg)->parent = NULL; \ (reg)->prenum = 0; \ (reg)->postnum = 0; \ (reg)->visited = 0; \ + (reg)->exit = 0; \ + (reg)->enter = 0; \ (reg)->link = NULL; \ } while (0) @@ -278,7 +297,7 @@ static void update_BasicBlock_regions(ir_node *blk, void *ctx) { * Creates a new Sequence region. */ static ir_region *new_Sequence(struct obstack *obst, ir_region *nset, int nset_len) { - ir_region *reg; + ir_region *reg, *next; int i; ALLOC_REG(obst, reg, ir_rk_Sequence); @@ -286,10 +305,13 @@ static ir_region *new_Sequence(struct obstack *obst, ir_region *nset, int nset_l reg->parts = NEW_ARR_D(ir_reg_or_blk, obst, nset_len); /* beware: list is in reverse order, reverse */ + next = nset; for (i = nset_len - 1; i >= 0; --i) { + nset = next; reg->parts[i].region = nset; nset->parent = reg; - nset = nset->link; + next = nset->link; + nset->link = NULL; } reg->nr = reg->parts[0].region->nr; @@ -506,14 +528,83 @@ static ir_region *new_WhileLoop(struct obstack *obst, ir_region *head) { } /* new_WhileLoop */ /** - * Return true if a is an ancestor of b in DFS search. + * Create a new new_NaturalLoop region. + */ +static ir_region *new_NaturalLoop(struct obstack *obst, ir_region *head) { + ir_region *reg, *c, *n; + int i, j, k, len, n_pred, n_succ; + + /* count number of parts */ + for (len = 0, c = head; c != NULL; c = c->link) + ++len; + + ALLOC_REG(obst, reg, ir_rk_WhileLoop); + + reg->nr = head->nr; + reg->parts = NEW_ARR_D(ir_reg_or_blk, obst, len); + + /* enter all parts */ + for (i = 0, c = head; c != NULL; c = n) { + reg->parts[i++].region = c; + c->parent = reg; + n = c->link; + c->link = NULL; + } + + /* count number of preds */ + n_pred = 0; + for (i = get_region_n_preds(head) - 1; i >= 0; --i) { + ir_region *pred = get_region_pred(head, i); + if (pred->parent != reg) + ++n_pred; + } + reg->pred = NEW_ARR_D(ir_region *, obst, n_pred); + for (j = 0, i = get_region_n_preds(head) - 1; i >= 0; --i) { + ir_region *pred = get_region_pred(head, i); + if (pred->parent != reg) + reg->pred[j++] = pred; + } + + /* count number of succs */ + n_succ = 0; + for (j = 0; j < len; ++j) { + ir_region *c = reg->parts[j].region; + for (i = get_region_n_succs(c) - 1; i >= 0; --i) { + ir_region *succ = get_region_succ(c, i); + if (succ->parent != reg) + ++n_succ; + } + } + reg->succ = NEW_ARR_D(ir_region *, obst, n_succ); + k = 0; + for (j = 0; j < len; ++j) { + ir_region *c = reg->parts[j].region; + for (i = get_region_n_succs(c) - 1; i >= 0; --i) { + ir_region *succ = get_region_succ(c, i); + if (succ->parent != reg) + reg->succ[k++] = succ; + } + } + + DEBUG_ONLY( + DB((dbg, LEVEL_2, " Created NaturalLoop(%u)Head(%u)\n", reg->nr, head->nr)); + for (i = 1; i < len; ++i) { + ir_region *p = reg->parts[i].region; + DB((dbg, LEVEL_2, " Body(%u)\n", p->nr)); + } + ) + return reg; +} /* new_NaturalLoop */ + +/** + * Return true if region a is an ancestor of region b in DFS search. */ static int is_ancestor(const ir_region *a, const ir_region *b) { return (a->prenum <= b->prenum && a->postnum > b->postnum); } /** - * Return true if region pred is a predecessor of region n. + * Return true if region pred is a predecessor of region n. */ static int pred_of(const ir_region *pred, const ir_region *n) { int i; @@ -525,7 +616,7 @@ static int pred_of(const ir_region *pred, const ir_region *n) { } /** - * Return true if region succ is a successor of region n. + * Return true if region succ is a successor of region n. */ static int succ_of(const ir_region *succ, const ir_region *n) { int i; @@ -537,7 +628,7 @@ static int succ_of(const ir_region *succ, const ir_region *n) { } /** - * Reverse linked list. + * Reverse a linked list of regions. */ static struct ir_region *reverse_list(ir_region *n) { ir_region *prev = NULL, *next; @@ -589,7 +680,8 @@ static ir_region *find_cyclic_region(ir_region *node) { } if (node->link && improper) { - /* found an improper region */ + /* found an improper region, do minimization */ + } return node; } @@ -614,15 +706,20 @@ static ir_region *cyclic_region_type(struct obstack *obst, ir_region *node) { } list = find_cyclic_region(node); - if (list->link && !LINK(list)->link && get_region_n_succs(list->link) == 1) { - return new_WhileLoop(obst, list); + if (list->link) { + if (!LINK(list)->link && get_region_n_succs(list->link) == 1) { + /* only one body block with only one successor (the head) */ + return new_WhileLoop(obst, list); + } + /* A Loop with one head */ + return new_NaturalLoop(obst, list); } return NULL; } /** - * Clear all links on a list. Needed, because we expect cleared links- + * Clear all links on a list. Needed, because we expect cleared links. */ static void clear_list(ir_region *list) { ir_region *next; @@ -825,6 +922,9 @@ static void replace_pred(ir_region *succ, ir_region *reg) { r = reg; } set_region_pred(succ, i, r); + } else { + /* the current region can be entered by this node */ + pred->enter = 1; } } ARR_SHRINKLEN(succ->pred, len); @@ -853,6 +953,9 @@ static void replace_succ(ir_region *pred, ir_region *reg) { r = reg; } set_region_succ(pred, i, r); + } else { + /* current region can be left by this node */ + succ->exit = 1; } } ARR_SHRINKLEN(pred->succ, len); @@ -874,7 +977,7 @@ static void reduce(walk_env *env, ir_region *reg) { replace_pred(succ, reg); } - /* second third: replace all succs in predessors */ + /* third step: replace all succs in predessors */ for (i = get_region_n_preds(reg) - 1; i >= 0; --i) { ir_region *pred = get_region_pred(reg, i); @@ -897,7 +1000,7 @@ static void reduce(walk_env *env, ir_region *reg) { ir_reg_tree *construct_region_tree(ir_graph *irg) { walk_env env; ir_graph *rem = current_ir_graph; - ir_reg_tree *res = xmalloc(sizeof(*res)); + ir_reg_tree *res = XMALLOC(ir_reg_tree); obstack_init(&res->obst); @@ -935,7 +1038,7 @@ ir_reg_tree *construct_region_tree(ir_graph *irg) { do { ir_region *reg, *n = env.post[postctr]; do { - if (n->parent) { + if (n->parent != NULL) { /* already folded */ break; }