X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fopt%2Fldstopt.c;h=4b76028a7356ac5e481e5d233b41d7aecb8f1cf9;hb=8f530048146e640fdfeb16b8ebe8bc997a1c8abe;hp=ab8205fe6dc54bef717f68401cc3504f2584c569;hpb=5efc71acbf0d5c24037e15c4bfbc4bcd617ae50f;p=libfirm diff --git a/ir/opt/ldstopt.c b/ir/opt/ldstopt.c index ab8205fe6..4b76028a7 100644 --- a/ir/opt/ldstopt.c +++ b/ir/opt/ldstopt.c @@ -1,43 +1,58 @@ /* - * Project: libFIRM - * File name: ir/opt/ldstopt.c - * Purpose: load store optimizations - * Author: - * Created: - * CVS-ID: $Id$ - * Copyright: (c) 1998-2004 Universität Karlsruhe - * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE. - */ -#ifdef HAVE_CONFIG_H -# include "config.h" -#endif - -#ifdef HAVE_ALLOCA_H -#include -#endif -#ifdef HAVE_MALLOC_H -#include -#endif -#ifdef HAVE_STRING_H -# include -#endif + * 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. + */ -# include "irnode_t.h" -# include "irgraph_t.h" -# include "irmode_t.h" -# include "iropt_t.h" -# include "ircons_t.h" -# include "irgmod.h" -# include "irgwalk.h" -# include "irvrfy.h" -# include "tv_t.h" -# include "dbginfo_t.h" -# include "iropt_dbg.h" -# include "irflag_t.h" -# include "array.h" -# include "irhooks.h" -# include "irtools.h" -# include "opt_polymorphy.h" +/** + * @file + * @brief Load/Store optimizations. + * @author Michael Beck + * @version $Id$ + */ +#include "config.h" + +#include + +#include "iroptimize.h" +#include "irnode_t.h" +#include "irgraph_t.h" +#include "irmode_t.h" +#include "iropt_t.h" +#include "ircons_t.h" +#include "irgmod.h" +#include "irgwalk.h" +#include "irvrfy.h" +#include "tv_t.h" +#include "dbginfo_t.h" +#include "iropt_dbg.h" +#include "irflag_t.h" +#include "array_t.h" +#include "irhooks.h" +#include "iredges.h" +#include "irtools.h" +#include "opt_polymorphy.h" +#include "irmemory.h" +#include "irphase_t.h" +#include "irgopt.h" +#include "set.h" +#include "debug.h" + +/** The debug handle. */ +DEBUG_ONLY(static firm_dbg_module_t *dbg;) #ifdef DO_CACHEOPT #include "cacheopt/cachesim.h" @@ -46,106 +61,98 @@ #undef IMAX #define IMAX(a,b) ((a) > (b) ? (a) : (b)) -#define MAX_PROJ IMAX(pn_Load_max, pn_Store_max) +#define MAX_PROJ IMAX(IMAX(pn_Load_max, pn_Store_max), pn_Call_max) enum changes_t { - DF_CHANGED = 1, /**< data flow changed */ - CF_CHANGED = 2, /**< control flow changed */ + DF_CHANGED = 1, /**< data flow changed */ + CF_CHANGED = 2, /**< control flow changed */ }; /** * walker environment */ typedef struct _walk_env_t { - struct obstack obst; /**< list of all stores */ - unsigned changes; /**< a bitmask of graph changes */ + struct obstack obst; /**< list of all stores */ + unsigned changes; /**< a bitmask of graph changes */ } walk_env_t; -/** - * flags for Load/Store - */ -enum ldst_flags_t { - LDST_VISITED = 1 /**< if set, this Load/Store is already visited */ -}; - -/** - * a Load/Store info - */ +/** A Load/Store info. */ typedef struct _ldst_info_t { - ir_node *projs[MAX_PROJ]; /**< list of Proj's of this node */ - ir_node *exc_block; /**< the exception block if available */ - int exc_idx; /**< predecessor index in the exception block */ - unsigned flags; /**< flags */ + ir_node *projs[MAX_PROJ]; /**< list of Proj's of this node */ + ir_node *exc_block; /**< the exception block if available */ + int exc_idx; /**< predecessor index in the exception block */ + unsigned visited; /**< visited counter for breaking loops */ } ldst_info_t; /** - * flags for control flow + * flags for control flow. */ enum block_flags_t { - BLOCK_HAS_COND = 1, /**< Block has conditional control flow */ - BLOCK_HAS_EXC = 2 /**< Block has exceptional control flow */ + BLOCK_HAS_COND = 1, /**< Block has conditional control flow */ + BLOCK_HAS_EXC = 2 /**< Block has exceptional control flow */ }; /** - * a Block info + * a Block info. */ typedef struct _block_info_t { - unsigned flags; /**< flags for the block */ + unsigned flags; /**< flags for the block */ } block_info_t; +/** the master visited flag for loop detection. */ +static unsigned master_visited = 0; + +#define INC_MASTER() ++master_visited +#define MARK_NODE(info) (info)->visited = master_visited +#define NODE_VISITED(info) (info)->visited >= master_visited + /** * get the Load/Store info of a node */ -static ldst_info_t *get_ldst_info(ir_node *node, walk_env_t *env) -{ - ldst_info_t *info = get_irn_link(node); +static ldst_info_t *get_ldst_info(ir_node *node, struct obstack *obst) { + ldst_info_t *info = get_irn_link(node); - if (! info) { - info = obstack_alloc(&env->obst, sizeof(*info)); - - memset(info, 0, sizeof(*info)); - - set_irn_link(node, info); - } - return info; -} + if (! info) { + info = obstack_alloc(obst, sizeof(*info)); + memset(info, 0, sizeof(*info)); + set_irn_link(node, info); + } + return info; +} /* get_ldst_info */ /** * get the Block info of a node */ -static block_info_t *get_block_info(ir_node *node, walk_env_t *env) -{ - block_info_t *info = get_irn_link(node); - - if (! info) { - info = obstack_alloc(&env->obst, sizeof(*info)); +static block_info_t *get_block_info(ir_node *node, struct obstack *obst) { + block_info_t *info = get_irn_link(node); - memset(info, 0, sizeof(*info)); - - set_irn_link(node, info); - } - return info; -} + if (! info) { + info = obstack_alloc(obst, sizeof(*info)); + memset(info, 0, sizeof(*info)); + set_irn_link(node, info); + } + return info; +} /* get_block_info */ /** * update the projection info for a Load/Store */ static unsigned update_projs(ldst_info_t *info, ir_node *proj) { - long nr = get_Proj_proj(proj); - - assert(0 <= nr && nr <= MAX_PROJ && "Wrong proj from LoadStore"); - - if (info->projs[nr]) { - /* there is already one, do CSE */ - exchange(proj, info->projs[nr]); - return DF_CHANGED; - } - else { - info->projs[nr] = proj; - return 0; - } -} + long nr = get_Proj_proj(proj); + + assert(0 <= nr && nr <= MAX_PROJ && "Wrong proj from LoadStore"); + + if (info->projs[nr]) { + /* there is already one, do CSE */ + exchange(proj, info->projs[nr]); + return DF_CHANGED; + } + else { + info->projs[nr] = proj; + return 0; + } +} /* update_projs */ /** * update the exception block info for a Load/Store node. @@ -156,15 +163,15 @@ static unsigned update_projs(ldst_info_t *info, ir_node *proj) */ static unsigned update_exc(ldst_info_t *info, ir_node *block, int pos) { - assert(info->exc_block == NULL && "more than one exception block found"); + assert(info->exc_block == NULL && "more than one exception block found"); - info->exc_block = block; - info->exc_idx = pos; - return 0; -} + info->exc_block = block; + info->exc_idx = pos; + return 0; +} /* update_exc */ -#define get_irn_out_n(node) (unsigned)PTR_TO_INT(get_irn_link(node)) -#define set_irn_out_n(node, n) set_irn_link(adr, INT_TO_PTR(n)) +/** Return the number of uses of an address node */ +#define get_irn_n_uses(adr) get_irn_n_edges(adr) /** * walker, collects all Load/Store/Proj nodes @@ -173,170 +180,166 @@ static unsigned update_exc(ldst_info_t *info, ir_node *block, int pos) */ static void collect_nodes(ir_node *node, void *env) { - ir_op *op = get_irn_op(node); - ir_node *pred, *blk, *pred_blk; - ldst_info_t *ldst_info; - walk_env_t *wenv = env; - - if (op == op_Proj) { - ir_node *adr; - ir_op *op; - - pred = get_Proj_pred(node); - op = get_irn_op(pred); - - if (op == op_Load) { - ldst_info = get_ldst_info(pred, wenv); - - wenv->changes |= update_projs(ldst_info, node); - - if ((ldst_info->flags & LDST_VISITED) == 0) { - adr = get_Load_ptr(pred); - set_irn_out_n(adr, get_irn_out_n(adr) + 1); - - ldst_info->flags |= LDST_VISITED; - } - - /* - * Place the Proj's to the same block as the - * predecessor Load. This is always ok and prevents - * "non-SSA" form after optimizations if the Proj - * is in a wrong block. - */ - blk = get_nodes_block(node); - pred_blk = get_nodes_block(pred); - if (blk != pred_blk) { - wenv->changes |= DF_CHANGED; - set_nodes_block(node, pred_blk); - } - } - else if (op == op_Store) { - ldst_info = get_ldst_info(pred, wenv); - - wenv->changes |= update_projs(ldst_info, node); - - if ((ldst_info->flags & LDST_VISITED) == 0) { - adr = get_Store_ptr(pred); - set_irn_out_n(adr, get_irn_out_n(adr) + 1); - - ldst_info->flags |= LDST_VISITED; - } - - /* - * Place the Proj's to the same block as the - * predecessor Store. This is always ok and prevents - * "non-SSA" form after optimizations if the Proj - * is in a wrong block. - */ - blk = get_nodes_block(node); - pred_blk = get_nodes_block(pred); - if (blk != pred_blk) { - wenv->changes |= DF_CHANGED; - set_nodes_block(node, pred_blk); - } - } - } - else if (op == op_Block) { /* check, if it's an exception block */ - int i; - - for (i = get_Block_n_cfgpreds(node) - 1; i >= 0; --i) { - ir_node *pred_block; - block_info_t *bl_info; - - pred = skip_Proj(get_Block_cfgpred(node, i)); - - /* ignore Bad predecessors, they will be removed later */ - if (is_Bad(pred)) - continue; - - pred_block = get_nodes_block(pred); - bl_info = get_block_info(pred_block, wenv); - - if (is_fragile_op(pred)) - bl_info->flags |= BLOCK_HAS_EXC; - else if (is_irn_forking(pred)) - bl_info->flags |= BLOCK_HAS_COND; - - if (get_irn_op(pred) == op_Load || get_irn_op(pred) == op_Store) { - ldst_info = get_ldst_info(pred, wenv); - - wenv->changes |= update_exc(ldst_info, node, i); - } - } - } -} + ir_opcode opcode = get_irn_opcode(node); + ir_node *pred, *blk, *pred_blk; + ldst_info_t *ldst_info; + walk_env_t *wenv = env; + + if (opcode == iro_Proj) { + pred = get_Proj_pred(node); + opcode = get_irn_opcode(pred); + + if (opcode == iro_Load || opcode == iro_Store || opcode == iro_Call) { + ldst_info = get_ldst_info(pred, &wenv->obst); + + wenv->changes |= update_projs(ldst_info, node); + + /* + * Place the Proj's to the same block as the + * predecessor Load. This is always ok and prevents + * "non-SSA" form after optimizations if the Proj + * is in a wrong block. + */ + blk = get_nodes_block(node); + pred_blk = get_nodes_block(pred); + if (blk != pred_blk) { + wenv->changes |= DF_CHANGED; + set_nodes_block(node, pred_blk); + } + } + } else if (opcode == iro_Block) { + int i; + + for (i = get_Block_n_cfgpreds(node) - 1; i >= 0; --i) { + ir_node *pred_block, *proj; + block_info_t *bl_info; + int is_exc = 0; + + pred = proj = get_Block_cfgpred(node, i); + + if (is_Proj(proj)) { + pred = get_Proj_pred(proj); + is_exc = get_Proj_proj(proj) == pn_Generic_X_except; + } + + /* ignore Bad predecessors, they will be removed later */ + if (is_Bad(pred)) + continue; + + pred_block = get_nodes_block(pred); + bl_info = get_block_info(pred_block, &wenv->obst); + + if (is_fragile_op(pred) && is_exc) + bl_info->flags |= BLOCK_HAS_EXC; + else if (is_irn_forking(pred)) + bl_info->flags |= BLOCK_HAS_COND; + + opcode = get_irn_opcode(pred); + if (is_exc && (opcode == iro_Load || opcode == iro_Store || opcode == iro_Call)) { + ldst_info = get_ldst_info(pred, &wenv->obst); + + wenv->changes |= update_exc(ldst_info, node, i); + } + } + } +} /* collect_nodes */ /** * Returns an entity if the address ptr points to a constant one. + * + * @param ptr the address + * + * @return an entity or NULL */ -static entity *find_constant_entity(ir_node *ptr) +static ir_entity *find_constant_entity(ir_node *ptr) { - for (;;) { - ir_op *op = get_irn_op(ptr); - - if (op == op_SymConst && (get_SymConst_kind(ptr) == symconst_addr_ent)) { - return get_SymConst_entity(ptr); - } - else if (op == op_Sel) { - entity *ent = get_Sel_entity(ptr); - type *tp = get_entity_owner(ent); - - /* Do not fiddle about polymorphy. */ - if (is_Class_type(get_entity_owner(ent)) && - ((get_entity_n_overwrites(ent) != 0) || - (get_entity_n_overwrittenby(ent) != 0) ) ) - return NULL; - - if (variability_constant == get_entity_variability(ent)) - return ent; - - if (is_Array_type(tp)) { - /* check bounds */ - int i, n; - - for (i = 0, n = get_Sel_n_indexs(ptr); i < n; ++i) { - ir_node *bound; - tarval *tlower, *tupper; - ir_node *index = get_Sel_index(ptr, i); - tarval *tv = computed_value(index); - - /* check if the index is constant */ - if (tv == tarval_bad) - return NULL; - - bound = get_array_lower_bound(tp, i); - tlower = computed_value(bound); - bound = get_array_upper_bound(tp, i); - tupper = computed_value(bound); - - if (tlower == tarval_bad || tupper == tarval_bad) - return NULL; - - if (tarval_cmp(tv, tlower) & pn_Cmp_Lt) - return NULL; - if (tarval_cmp(tupper, tv) & pn_Cmp_Lt) - return NULL; - - /* ok, bounds check finished */ - } - } - - /* try next */ - ptr = get_Sel_ptr(ptr); - } - else - return NULL; - } -} + for (;;) { + if (is_SymConst(ptr) && get_SymConst_kind(ptr) == symconst_addr_ent) { + return get_SymConst_entity(ptr); + } else if (is_Sel(ptr)) { + ir_entity *ent = get_Sel_entity(ptr); + ir_type *tp = get_entity_owner(ent); + + /* Do not fiddle with polymorphism. */ + if (is_Class_type(get_entity_owner(ent)) && + ((get_entity_n_overwrites(ent) != 0) || + (get_entity_n_overwrittenby(ent) != 0) ) ) + return NULL; + + if (is_Array_type(tp)) { + /* check bounds */ + int i, n; + + for (i = 0, n = get_Sel_n_indexs(ptr); i < n; ++i) { + ir_node *bound; + tarval *tlower, *tupper; + ir_node *index = get_Sel_index(ptr, i); + tarval *tv = computed_value(index); + + /* check if the index is constant */ + if (tv == tarval_bad) + return NULL; + + bound = get_array_lower_bound(tp, i); + tlower = computed_value(bound); + bound = get_array_upper_bound(tp, i); + tupper = computed_value(bound); + + if (tlower == tarval_bad || tupper == tarval_bad) + return NULL; + + if (tarval_cmp(tv, tlower) & pn_Cmp_Lt) + return NULL; + if (tarval_cmp(tupper, tv) & pn_Cmp_Lt) + return NULL; + + /* ok, bounds check finished */ + } + } + + if (variability_constant == get_entity_variability(ent)) + return ent; + + /* try next */ + ptr = get_Sel_ptr(ptr); + } else if (is_Add(ptr)) { + ir_node *l = get_Add_left(ptr); + ir_node *r = get_Add_right(ptr); + + if (get_irn_mode(l) == get_irn_mode(ptr) && is_Const(r)) + ptr = l; + else if (get_irn_mode(r) == get_irn_mode(ptr) && is_Const(l)) + ptr = r; + else + return NULL; + + /* for now, we support only one addition, reassoc should fold all others */ + if (! is_SymConst(ptr) && !is_Sel(ptr)) + return NULL; + } else if (is_Sub(ptr)) { + ir_node *l = get_Sub_left(ptr); + ir_node *r = get_Sub_right(ptr); + + if (get_irn_mode(l) == get_irn_mode(ptr) && is_Const(r)) + ptr = l; + else + return NULL; + /* for now, we support only one substraction, reassoc should fold all others */ + if (! is_SymConst(ptr) && !is_Sel(ptr)) + return NULL; + } else + return NULL; + } +} /* find_constant_entity */ /** * Return the Selection index of a Sel node from dimension n */ static long get_Sel_array_index_long(ir_node *n, int dim) { - ir_node *index = get_Sel_index(n, dim); - assert(get_irn_op(index) == op_Const); - return get_tarval_long(get_Const_tarval(index)); -} + ir_node *index = get_Sel_index(n, dim); + assert(is_Const(index)); + return get_tarval_long(get_Const_tarval(index)); +} /* get_Sel_array_index_long */ /** * Returns the accessed component graph path for an @@ -347,613 +350,1958 @@ static long get_Sel_array_index_long(ir_node *n, int dim) { * of the address */ static compound_graph_path *rec_get_accessed_path(ir_node *ptr, int depth) { - compound_graph_path *res = NULL; - entity *root, *field; - int path_len, pos; - - if (get_irn_op(ptr) == op_SymConst) { - /* a SymConst. If the depth is 0, this is an access to a global - * entity and we don't need a component path, else we know - * at least it's length. - */ - assert(get_SymConst_kind(ptr) == symconst_addr_ent); - root = get_SymConst_entity(ptr); - res = (depth == 0) ? NULL : new_compound_graph_path(get_entity_type(root), depth); - } - else { - assert(get_irn_op(ptr) == op_Sel); - /* it's a Sel, go up until we find the root */ - res = rec_get_accessed_path(get_Sel_ptr(ptr), depth+1); - - /* fill up the step in the path at the current position */ - field = get_Sel_entity(ptr); - path_len = get_compound_graph_path_length(res); - pos = path_len - depth - 1; - set_compound_graph_path_node(res, pos, field); - - if (is_Array_type(get_entity_owner(field))) { - assert(get_Sel_n_indexs(ptr) == 1 && "multi dim arrays not implemented"); - set_compound_graph_path_array_index(res, pos, get_Sel_array_index_long(ptr, 0)); - } - } - return res; -} + compound_graph_path *res = NULL; + ir_entity *root, *field, *ent; + int path_len, pos, idx; + tarval *tv; + ir_type *tp; + + if (is_SymConst(ptr)) { + /* a SymConst. If the depth is 0, this is an access to a global + * entity and we don't need a component path, else we know + * at least its length. + */ + assert(get_SymConst_kind(ptr) == symconst_addr_ent); + root = get_SymConst_entity(ptr); + res = (depth == 0) ? NULL : new_compound_graph_path(get_entity_type(root), depth); + } else if (is_Sel(ptr)) { + /* it's a Sel, go up until we find the root */ + res = rec_get_accessed_path(get_Sel_ptr(ptr), depth+1); + if (res == NULL) + return NULL; + + /* fill up the step in the path at the current position */ + field = get_Sel_entity(ptr); + path_len = get_compound_graph_path_length(res); + pos = path_len - depth - 1; + set_compound_graph_path_node(res, pos, field); + + if (is_Array_type(get_entity_owner(field))) { + assert(get_Sel_n_indexs(ptr) == 1 && "multi dim arrays not implemented"); + set_compound_graph_path_array_index(res, pos, get_Sel_array_index_long(ptr, 0)); + } + } else if (is_Add(ptr)) { + ir_node *l = get_Add_left(ptr); + ir_node *r = get_Add_right(ptr); + ir_mode *mode = get_irn_mode(ptr); + tarval *tmp; + + if (is_Const(r) && get_irn_mode(l) == mode) { + ptr = l; + tv = get_Const_tarval(r); + } else { + ptr = r; + tv = get_Const_tarval(l); + } +ptr_arith: + mode = get_tarval_mode(tv); + tmp = tv; + + /* ptr must be a Sel or a SymConst, this was checked in find_constant_entity() */ + if (is_Sel(ptr)) { + field = get_Sel_entity(ptr); + } else { + field = get_SymConst_entity(ptr); + } + idx = 0; + for (ent = field;;) { + unsigned size; + tarval *sz, *tv_index, *tlower, *tupper; + ir_node *bound; + + tp = get_entity_type(ent); + if (! is_Array_type(tp)) + break; + ent = get_array_element_entity(tp); + size = get_type_size_bytes(get_entity_type(ent)); + sz = new_tarval_from_long(size, mode); + + tv_index = tarval_div(tmp, sz); + tmp = tarval_mod(tmp, sz); + + if (tv_index == tarval_bad || tmp == tarval_bad) + return NULL; + + assert(get_array_n_dimensions(tp) == 1 && "multiarrays not implemented"); + bound = get_array_lower_bound(tp, 0); + tlower = computed_value(bound); + bound = get_array_upper_bound(tp, 0); + tupper = computed_value(bound); + + if (tlower == tarval_bad || tupper == tarval_bad) + return NULL; + + if (tarval_cmp(tv_index, tlower) & pn_Cmp_Lt) + return NULL; + if (tarval_cmp(tupper, tv_index) & pn_Cmp_Lt) + return NULL; + + /* ok, bounds check finished */ + ++idx; + } + if (! tarval_is_null(tmp)) { + /* access to some struct/union member */ + return NULL; + } + + /* should be at least ONE array */ + if (idx == 0) + return NULL; + + res = rec_get_accessed_path(ptr, depth + idx); + if (res == NULL) + return NULL; + + path_len = get_compound_graph_path_length(res); + pos = path_len - depth - idx; + + for (ent = field;;) { + unsigned size; + tarval *sz, *tv_index; + long index; + + tp = get_entity_type(ent); + if (! is_Array_type(tp)) + break; + ent = get_array_element_entity(tp); + set_compound_graph_path_node(res, pos, ent); + + size = get_type_size_bytes(get_entity_type(ent)); + sz = new_tarval_from_long(size, mode); + + tv_index = tarval_div(tv, sz); + tv = tarval_mod(tv, sz); + + /* worked above, should work again */ + assert(tv_index != tarval_bad && tv != tarval_bad); + + /* bounds already checked above */ + index = get_tarval_long(tv_index); + set_compound_graph_path_array_index(res, pos, index); + ++pos; + } + } else if (is_Sub(ptr)) { + ir_node *l = get_Sub_left(ptr); + ir_node *r = get_Sub_right(ptr); + + ptr = l; + tv = get_Const_tarval(r); + tv = tarval_neg(tv); + goto ptr_arith; + } + return res; +} /* rec_get_accessed_path */ -/** Returns an access path or NULL. The access path is only - * valid, if the graph is in phase_high and _no_ address computation is used. +/** + * Returns an access path or NULL. The access path is only + * valid, if the graph is in phase_high and _no_ address computation is used. */ static compound_graph_path *get_accessed_path(ir_node *ptr) { - return rec_get_accessed_path(ptr, 0); + compound_graph_path *gr = rec_get_accessed_path(ptr, 0); + return gr; +} /* get_accessed_path */ + +typedef struct path_entry { + ir_entity *ent; + struct path_entry *next; + long index; +} path_entry; + +static ir_node *rec_find_compound_ent_value(ir_node *ptr, path_entry *next) { + path_entry entry, *p; + ir_entity *ent, *field; + ir_initializer_t *initializer; + tarval *tv; + ir_type *tp; + unsigned n; + + entry.next = next; + if (is_SymConst(ptr)) { + /* found the root */ + ent = get_SymConst_entity(ptr); + initializer = get_entity_initializer(ent); + for (p = next; p != NULL;) { + if (initializer->kind != IR_INITIALIZER_COMPOUND) + return NULL; + n = get_initializer_compound_n_entries(initializer); + tp = get_entity_type(ent); + + if (is_Array_type(tp)) { + ent = get_array_element_entity(tp); + if (ent != p->ent) { + /* a missing [0] */ + if (0 >= n) + return NULL; + initializer = get_initializer_compound_value(initializer, 0); + continue; + } + } + if (p->index >= (int) n) + return NULL; + initializer = get_initializer_compound_value(initializer, p->index); + + ent = p->ent; + p = p->next; + } + tp = get_entity_type(ent); + while (is_Array_type(tp)) { + ent = get_array_element_entity(tp); + tp = get_entity_type(ent); + /* a missing [0] */ + n = get_initializer_compound_n_entries(initializer); + if (0 >= n) + return NULL; + initializer = get_initializer_compound_value(initializer, 0); + } + + switch (initializer->kind) { + case IR_INITIALIZER_CONST: + return get_initializer_const_value(initializer); + case IR_INITIALIZER_TARVAL: + case IR_INITIALIZER_NULL: + default: + return NULL; + } + } else if (is_Sel(ptr)) { + entry.ent = field = get_Sel_entity(ptr); + tp = get_entity_owner(field); + if (is_Array_type(tp)) { + assert(get_Sel_n_indexs(ptr) == 1 && "multi dim arrays not implemented"); + entry.index = get_Sel_array_index_long(ptr, 0) - get_array_lower_bound_int(tp, 0); + } else { + int i, n_members = get_compound_n_members(tp); + for (i = 0; i < n_members; ++i) { + if (get_compound_member(tp, i) == field) + break; + } + if (i >= n_members) { + /* not found: should NOT happen */ + return NULL; + } + entry.index = i; + } + return rec_find_compound_ent_value(get_Sel_ptr(ptr), &entry); + } else if (is_Add(ptr)) { + ir_node *l = get_Add_left(ptr); + ir_node *r = get_Add_right(ptr); + ir_mode *mode; + unsigned pos; + + if (is_Const(r)) { + ptr = l; + tv = get_Const_tarval(r); + } else { + ptr = r; + tv = get_Const_tarval(l); + } +ptr_arith: + mode = get_tarval_mode(tv); + + /* ptr must be a Sel or a SymConst, this was checked in find_constant_entity() */ + if (is_Sel(ptr)) { + field = get_Sel_entity(ptr); + } else { + field = get_SymConst_entity(ptr); + } + + /* count needed entries */ + pos = 0; + for (ent = field;;) { + tp = get_entity_type(ent); + if (! is_Array_type(tp)) + break; + ent = get_array_element_entity(tp); + ++pos; + } + /* should be at least ONE entry */ + if (pos == 0) + return NULL; + + /* allocate the right number of entries */ + NEW_ARR_A(path_entry, p, pos); + + /* fill them up */ + pos = 0; + for (ent = field;;) { + unsigned size; + tarval *sz, *tv_index, *tlower, *tupper; + long index; + ir_node *bound; + + tp = get_entity_type(ent); + if (! is_Array_type(tp)) + break; + ent = get_array_element_entity(tp); + p[pos].ent = ent; + p[pos].next = &p[pos + 1]; + + size = get_type_size_bytes(get_entity_type(ent)); + sz = new_tarval_from_long(size, mode); + + tv_index = tarval_div(tv, sz); + tv = tarval_mod(tv, sz); + + if (tv_index == tarval_bad || tv == tarval_bad) + return NULL; + + assert(get_array_n_dimensions(tp) == 1 && "multiarrays not implemented"); + bound = get_array_lower_bound(tp, 0); + tlower = computed_value(bound); + bound = get_array_upper_bound(tp, 0); + tupper = computed_value(bound); + + if (tlower == tarval_bad || tupper == tarval_bad) + return NULL; + + if (tarval_cmp(tv_index, tlower) & pn_Cmp_Lt) + return NULL; + if (tarval_cmp(tupper, tv_index) & pn_Cmp_Lt) + return NULL; + + /* ok, bounds check finished */ + index = get_tarval_long(tv_index); + p[pos].index = index; + ++pos; + } + if (! tarval_is_null(tv)) { + /* hmm, wrong access */ + return NULL; + } + p[pos - 1].next = next; + return rec_find_compound_ent_value(ptr, p); + } else if (is_Sub(ptr)) { + ir_node *l = get_Sub_left(ptr); + ir_node *r = get_Sub_right(ptr); + + ptr = l; + tv = get_Const_tarval(r); + tv = tarval_neg(tv); + goto ptr_arith; + } + return NULL; +} + +static ir_node *find_compound_ent_value(ir_node *ptr) { + return rec_find_compound_ent_value(ptr, NULL); } +/* forward */ +static void reduce_adr_usage(ir_node *ptr); + +/** + * Update a Load that may have lost its users. + */ +static void handle_load_update(ir_node *load) { + ldst_info_t *info = get_irn_link(load); + + /* do NOT touch volatile loads for now */ + if (get_Load_volatility(load) == volatility_is_volatile) + return; + + if (! info->projs[pn_Load_res] && ! info->projs[pn_Load_X_except]) { + ir_node *ptr = get_Load_ptr(load); + ir_node *mem = get_Load_mem(load); + + /* a Load whose value is neither used nor exception checked, remove it */ + exchange(info->projs[pn_Load_M], mem); + if (info->projs[pn_Load_X_regular]) + exchange(info->projs[pn_Load_X_regular], new_r_Jmp(get_nodes_block(load))); + kill_node(load); + reduce_adr_usage(ptr); + } +} /* handle_load_update */ + +/** + * A use of an address node has vanished. Check if this was a Proj + * node and update the counters. + */ +static void reduce_adr_usage(ir_node *ptr) { + if (is_Proj(ptr)) { + if (get_irn_n_edges(ptr) <= 0) { + /* this Proj is dead now */ + ir_node *pred = get_Proj_pred(ptr); + + if (is_Load(pred)) { + ldst_info_t *info = get_irn_link(pred); + info->projs[get_Proj_proj(ptr)] = NULL; + + /* this node lost its result proj, handle that */ + handle_load_update(pred); + } + } + } +} /* reduce_adr_usage */ + +/** + * Check, if an already existing value of mode old_mode can be converted + * into the needed one new_mode without loss. + */ +static int can_use_stored_value(ir_mode *old_mode, ir_mode *new_mode) { + if (old_mode == new_mode) + return 1; + + /* if both modes are two-complement ones, we can always convert the + Stored value into the needed one. */ + if (get_mode_size_bits(old_mode) >= get_mode_size_bits(new_mode) && + get_mode_arithmetic(old_mode) == irma_twos_complement && + get_mode_arithmetic(new_mode) == irma_twos_complement) + return 1; + return 0; +} /* can_use_stored_value */ + +/** + * Check whether a Call is at least pure, ie. does only read memory. + */ +static unsigned is_Call_pure(ir_node *call) { + ir_type *call_tp = get_Call_type(call); + unsigned prop = get_method_additional_properties(call_tp); + + /* check first the call type */ + if ((prop & (mtp_property_const|mtp_property_pure)) == 0) { + /* try the called entity */ + ir_node *ptr = get_Call_ptr(call); + + if (is_Global(ptr)) { + ir_entity *ent = get_Global_entity(ptr); + + prop = get_entity_additional_properties(ent); + } + } + return (prop & (mtp_property_const|mtp_property_pure)) != 0; +} /* is_Call_pure */ + +static ir_node *get_base_and_offset(ir_node *ptr, long *pOffset) +{ + ir_mode *mode = get_irn_mode(ptr); + long offset = 0; + + /* TODO: long might not be enough, we should probably use some tarval thingy... */ + for (;;) { + if (is_Add(ptr)) { + ir_node *l = get_Add_left(ptr); + ir_node *r = get_Add_right(ptr); + + if (get_irn_mode(l) != mode || !is_Const(r)) + break; + + offset += get_tarval_long(get_Const_tarval(r)); + ptr = l; + } else if (is_Sub(ptr)) { + ir_node *l = get_Sub_left(ptr); + ir_node *r = get_Sub_right(ptr); + + if (get_irn_mode(l) != mode || !is_Const(r)) + break; + + offset -= get_tarval_long(get_Const_tarval(r)); + ptr = l; + } else if (is_Sel(ptr)) { + ir_entity *ent = get_Sel_entity(ptr); + ir_type *tp = get_entity_owner(ent); + + if (is_Array_type(tp)) { + int size; + ir_node *index; + + /* only one dimensional arrays yet */ + if (get_Sel_n_indexs(ptr) != 1) + break; + index = get_Sel_index(ptr, 0); + if (! is_Const(index)) + break; + + tp = get_entity_type(ent); + if (get_type_state(tp) != layout_fixed) + break; + + size = get_type_size_bytes(tp); + offset += size * get_tarval_long(get_Const_tarval(index)); + } else { + if (get_type_state(tp) != layout_fixed) + break; + offset += get_entity_offset(ent); + } + ptr = get_Sel_ptr(ptr); + } else + break; + } + + *pOffset = offset; + return ptr; +} + +static int try_load_after_store(ir_node *load, + ir_node *load_base_ptr, long load_offset, ir_node *store) +{ + ldst_info_t *info; + ir_node *store_ptr = get_Store_ptr(store); + long store_offset; + ir_node *store_base_ptr = get_base_and_offset(store_ptr, &store_offset); + ir_node *store_value; + ir_mode *store_mode; + ir_node *load_ptr; + ir_mode *load_mode; + long load_mode_len; + long store_mode_len; + long delta; + int res; + + if (load_base_ptr != store_base_ptr) + return 0; + + load_mode = get_Load_mode(load); + load_mode_len = get_mode_size_bytes(load_mode); + store_mode = get_irn_mode(get_Store_value(store)); + store_mode_len = get_mode_size_bytes(store_mode); + delta = load_offset - store_offset; + store_value = get_Store_value(store); + + if (delta != 0 || store_mode != load_mode) { + if (delta < 0 || delta + load_mode_len > store_mode_len) + return 0; + + if (get_mode_arithmetic(store_mode) != irma_twos_complement || + get_mode_arithmetic(load_mode) != irma_twos_complement) + return 0; + + + /* produce a shift to adjust offset delta */ + if (delta > 0) { + ir_node *cnst; + + /* FIXME: only true for little endian */ + cnst = new_Const_long(mode_Iu, delta * 8); + store_value = new_r_Shr(get_nodes_block(load), + store_value, cnst, store_mode); + } + + /* add an convert if needed */ + if (store_mode != load_mode) { + store_value = new_r_Conv(get_nodes_block(load), store_value, load_mode); + } + } + + DBG_OPT_RAW(load, store_value); + + info = get_irn_link(load); + if (info->projs[pn_Load_M]) + exchange(info->projs[pn_Load_M], get_Load_mem(load)); + + res = 0; + /* no exception */ + if (info->projs[pn_Load_X_except]) { + exchange( info->projs[pn_Load_X_except], new_Bad()); + res |= CF_CHANGED; + } + if (info->projs[pn_Load_X_regular]) { + exchange( info->projs[pn_Load_X_regular], new_r_Jmp(get_nodes_block(load))); + res |= CF_CHANGED; + } + + if (info->projs[pn_Load_res]) + exchange(info->projs[pn_Load_res], store_value); + + load_ptr = get_Load_ptr(load); + kill_node(load); + reduce_adr_usage(load_ptr); + return res | DF_CHANGED; +} + +/** + * Follow the memory chain as long as there are only Loads, + * alias free Stores, and constant Calls and try to replace the + * current Load by a previous ones. + * Note that in unreachable loops it might happen that we reach + * load again, as well as we can fall into a cycle. + * We break such cycles using a special visited flag. + * + * INC_MASTER() must be called before dive into + */ +static unsigned follow_Mem_chain(ir_node *load, ir_node *curr) { + unsigned res = 0; + ldst_info_t *info = get_irn_link(load); + ir_node *pred; + ir_node *ptr = get_Load_ptr(load); + ir_node *mem = get_Load_mem(load); + ir_mode *load_mode = get_Load_mode(load); + + for (pred = curr; load != pred; ) { + ldst_info_t *pred_info = get_irn_link(pred); + + /* + * a Load immediately after a Store -- a read after write. + * We may remove the Load, if both Load & Store does not have an + * exception handler OR they are in the same MacroBlock. In the latter + * case the Load cannot throw an exception when the previous Store was + * quiet. + * + * Why we need to check for Store Exception? If the Store cannot + * be executed (ROM) the exception handler might simply jump into + * the load MacroBlock :-( + * We could make it a little bit better if we would know that the + * exception handler of the Store jumps directly to the end... + */ + if (is_Store(pred) && ((pred_info->projs[pn_Store_X_except] == NULL + && info->projs[pn_Load_X_except] == NULL) + || get_nodes_MacroBlock(load) == get_nodes_MacroBlock(pred))) + { + long load_offset; + ir_node *base_ptr = get_base_and_offset(ptr, &load_offset); + int changes = try_load_after_store(load, base_ptr, load_offset, pred); + + if (changes != 0) + return res | changes; + } else if (is_Load(pred) && get_Load_ptr(pred) == ptr && + can_use_stored_value(get_Load_mode(pred), load_mode)) { + /* + * a Load after a Load -- a read after read. + * We may remove the second Load, if it does not have an exception handler + * OR they are in the same MacroBlock. In the later case the Load cannot + * throw an exception when the previous Load was quiet. + * + * Here, there is no need to check if the previous Load has an exception + * hander because they would have exact the same exception... + */ + if (info->projs[pn_Load_X_except] == NULL || get_nodes_MacroBlock(load) == get_nodes_MacroBlock(pred)) { + ir_node *value; + + DBG_OPT_RAR(load, pred); + + /* the result is used */ + if (info->projs[pn_Load_res]) { + if (pred_info->projs[pn_Load_res] == NULL) { + /* create a new Proj again */ + pred_info->projs[pn_Load_res] = new_r_Proj(get_nodes_block(pred), pred, get_Load_mode(pred), pn_Load_res); + } + value = pred_info->projs[pn_Load_res]; + + /* add an convert if needed */ + if (get_Load_mode(pred) != load_mode) { + value = new_r_Conv(get_nodes_block(load), value, load_mode); + } + + exchange(info->projs[pn_Load_res], value); + } + + if (info->projs[pn_Load_M]) + exchange(info->projs[pn_Load_M], mem); + + /* no exception */ + if (info->projs[pn_Load_X_except]) { + exchange(info->projs[pn_Load_X_except], new_Bad()); + res |= CF_CHANGED; + } + if (info->projs[pn_Load_X_regular]) { + exchange( info->projs[pn_Load_X_regular], new_r_Jmp(get_nodes_block(load))); + res |= CF_CHANGED; + } + + kill_node(load); + reduce_adr_usage(ptr); + return res |= DF_CHANGED; + } + } + + if (is_Store(pred)) { + /* check if we can pass through this store */ + ir_alias_relation rel = get_alias_relation( + current_ir_graph, + get_Store_ptr(pred), + get_irn_mode(get_Store_value(pred)), + ptr, load_mode); + /* if the might be an alias, we cannot pass this Store */ + if (rel != ir_no_alias) + break; + pred = skip_Proj(get_Store_mem(pred)); + } else if (is_Load(pred)) { + pred = skip_Proj(get_Load_mem(pred)); + } else if (is_Call(pred)) { + if (is_Call_pure(pred)) { + /* The called graph is at least pure, so there are no Store's + in it. We can handle it like a Load and skip it. */ + pred = skip_Proj(get_Call_mem(pred)); + } else { + /* there might be Store's in the graph, stop here */ + break; + } + } else { + /* follow only Load chains */ + break; + } + + /* check for cycles */ + if (NODE_VISITED(pred_info)) + break; + MARK_NODE(pred_info); + } + + if (is_Sync(pred)) { + int i; + + /* handle all Sync predecessors */ + for (i = get_Sync_n_preds(pred) - 1; i >= 0; --i) { + res |= follow_Mem_chain(load, skip_Proj(get_Sync_pred(pred, i))); + if (res) + return res; + } + } + + return res; +} /* follow_Mem_chain */ + +/* + * Check if we can replace the load by a given const from + * the const code irg. + */ +ir_node *can_replace_load_by_const(const ir_node *load, ir_node *c) { + ir_mode *c_mode = get_irn_mode(c); + ir_mode *l_mode = get_Load_mode(load); + ir_node *res = NULL; + + if (c_mode != l_mode) { + /* check, if the mode matches OR can be easily converted info */ + if (is_reinterpret_cast(c_mode, l_mode)) { + /* we can safely cast */ + dbg_info *dbg = get_irn_dbg_info(load); + ir_node *block = get_nodes_block(load); + + /* copy the value from the const code irg and cast it */ + res = copy_const_value(dbg, c); + res = new_rd_Conv(dbg, block, res, l_mode); + } + } else { + /* copy the value from the const code irg */ + res = copy_const_value(get_irn_dbg_info(load), c); + } + return res; +} /* can_replace_load_by_const */ + /** * optimize a Load + * + * @param load the Load node */ static unsigned optimize_load(ir_node *load) { - ldst_info_t *info = get_irn_link(load); - ir_mode *load_mode = get_Load_mode(load); - ir_node *pred, *mem, *ptr, *new_node; - entity *ent; - unsigned res = 0; - - /* do NOT touch volatile loads for now */ - if (get_Load_volatility(load) == volatility_is_volatile) - return 0; - - /* the address of the load to be optimized */ - ptr = get_Load_ptr(load); - - /* - * Check if we can remove the exception from a Load: - * This can be done, if the address is from an Sel(Alloc) and - * the Sel type is a subtype of the allocated type. - * - * This optimizes some often used OO constructs, - * like x = new O; x->t; - */ - if (info->projs[pn_Load_X_except]) { - if (get_irn_op(ptr) == op_Sel) { - ir_node *mem = get_Sel_mem(ptr); - - if (get_irn_op(skip_Proj(mem)) == op_Alloc) { - /* ok, check the types */ - entity *ent = get_Sel_entity(ptr); - type *s_type = get_entity_type(ent); - type *a_type = get_Alloc_type(mem); - - if (is_subclass_of(s_type, a_type)) { - /* ok, condition met: there can't be an exception because - * Alloc guarantees that enough memory was allocated */ - - exchange(info->projs[pn_Load_X_except], new_Bad()); - info->projs[pn_Load_X_except] = NULL; - res |= CF_CHANGED; - } - } - } - else if ((get_irn_op(skip_Proj(ptr)) == op_Alloc) || - ((get_irn_op(ptr) == op_Cast) && (get_irn_op(skip_Proj(get_Cast_op(ptr))) == op_Alloc))) { - /* simple case: a direct load after an Alloc. Firm Alloc throw - * an exception in case of out-of-memory. So, there is no way for an - * exception in this load. - * This code is constructed by the "exception lowering" in the Jack compiler. - */ - exchange(info->projs[pn_Load_X_except], new_Bad()); - info->projs[pn_Load_X_except] = NULL; - res |= CF_CHANGED; - } - } - - /* the mem of the Load. Must still be returned after optimization */ - mem = get_Load_mem(load); - - if (! info->projs[pn_Load_res] && ! info->projs[pn_Load_X_except]) { - /* a Load which value is neither used nor exception checked, remove it */ - exchange(info->projs[pn_Load_M], mem); - - return res | DF_CHANGED; - } - - /* Load from a constant polymorphic field, where we can resolve - polymorphy. */ - new_node = transform_node_Load(load); - if (new_node != load) { - if (info->projs[pn_Load_M]) { - exchange(info->projs[pn_Load_M], mem); - info->projs[pn_Load_M] = NULL; - } - if (info->projs[pn_Load_X_except]) { - exchange(info->projs[pn_Load_X_except], new_Bad()); - info->projs[pn_Load_X_except] = NULL; - } - if (info->projs[pn_Load_res]) - exchange(info->projs[pn_Load_res], new_node); - return res | DF_CHANGED; - } - - /* check if we can determine the entity that will be loaded */ - ent = find_constant_entity(ptr); - if (ent) { - if ((allocation_static == get_entity_allocation(ent)) && - (visibility_external_allocated != get_entity_visibility(ent))) { - /* a static allocation that is not external: there should be NO exception - * when loading. */ - - /* no exception, clear the info field as it might be checked later again */ - if (info->projs[pn_Load_X_except]) { - exchange(info->projs[pn_Load_X_except], new_Bad()); - info->projs[pn_Load_X_except] = NULL; - res |= CF_CHANGED; - } - - if (variability_constant == get_entity_variability(ent) - && is_atomic_entity(ent)) { - /* Might not be atomic after - lowering of Sels. In this - case we could also load, but - it's more complicated. */ - /* more simpler case: we load the content of a constant value: - * replace it by the constant itself - */ - - /* no memory */ - if (info->projs[pn_Load_M]) { - exchange(info->projs[pn_Load_M], mem); - res |= DF_CHANGED; - } - - /* no result :-) */ - if (info->projs[pn_Load_res]) { - if (is_atomic_entity(ent)) { - ir_node *c = copy_const_value(get_atomic_ent_value(ent)); - - DBG_OPT_RC(load, c); - exchange(info->projs[pn_Load_res], c); - return DF_CHANGED | res; - } - } - } - else if (variability_constant == get_entity_variability(ent)) { - compound_graph_path *path = get_accessed_path(ptr); - - if (path) { - ir_node *c; - - assert(is_proper_compound_graph_path(path, get_compound_graph_path_length(path)-1)); - /* - { - int j; - for (j = 0; j < get_compound_graph_path_length(path); ++j) { - entity *node = get_compound_graph_path_node(path, j); - fprintf(stdout, ".%s", get_entity_name(node)); - if (is_Array_type(get_entity_owner(node))) - fprintf(stdout, "[%d]", get_compound_graph_path_array_index(path, j)); - } - printf("\n"); - } - */ - - c = get_compound_ent_value_by_path(ent, path); - free_compound_graph_path(path); - - /* printf(" cons: "); DDMN(c); */ - - if (info->projs[pn_Load_M]) { - exchange(info->projs[pn_Load_M], mem); - res |= DF_CHANGED; - } - if (info->projs[pn_Load_res]) { - exchange(info->projs[pn_Load_res], copy_const_value(c)); - return res | DF_CHANGED; - } - } - else { - /* We can not determine a correct access path. E.g., in jack, we load - a byte from an object to generate an exception. Happens in test program - Reflectiontest. - printf(">>>>>>>>>>>>> Found access to constant entity %s in function %s\n", get_entity_name(ent), - get_entity_name(get_irg_entity(current_ir_graph))); - printf(" load: "); DDMN(load); - printf(" ptr: "); DDMN(ptr); - */ - } - } - } - } - - /* Check, if the address of this load is used more than once. - * If not, this load cannot be removed in any case. */ - if (get_irn_out_n(ptr) <= 1) - return res; - - /* follow the memory chain as long as there are only Loads - * and try to replace current Load or Store by a previous one - */ - for (pred = skip_Proj(mem); ; pred = skip_Proj(get_Load_mem(pred))) { - /* - * BEWARE: one might think that checking the modes is useless, because - * if the pointers are identical, they refer to the same object. - * This is only true in strong typed languages, not in C were the following - * is possible a = *(type1 *)p; b = *(type2 *)p ... - */ - - if (get_irn_op(pred) == op_Store && get_Store_ptr(pred) == ptr && - get_irn_mode(get_Store_value(pred)) == load_mode) { - ldst_info_t *pred_info = get_irn_link(pred); - - /* - * a Load immediately after a Store -- a read after write. - * We may remove the Load, if both Load & Store does not have an exception handler - * OR they are in the same block. In the latter case the Load cannot - * throw an exception when the previous Store was quiet. - * - * Why we need to check for Store Exception? If the Store cannot - * be executed (ROM) the exception handler might simply jump into - * the load block :-( - * We could make it a little bit better if we would know that the exception - * handler of the Store jumps directly to the end... - */ - if ((!pred_info->projs[pn_Store_X_except] && !info->projs[pn_Load_X_except]) || - get_nodes_block(load) == get_nodes_block(pred)) { - ir_node *value = get_Store_value(pred); - - DBG_OPT_RAW(load, value); - if (info->projs[pn_Load_M]) - exchange(info->projs[pn_Load_M], mem); - - /* no exception */ - if (info->projs[pn_Load_X_except]) { - exchange( info->projs[pn_Load_X_except], new_Bad()); - res |= CF_CHANGED; - } - - if (info->projs[pn_Load_res]) - exchange(info->projs[pn_Load_res], value); - - return res | DF_CHANGED; - } - } - else if (get_irn_op(pred) == op_Load && get_Load_ptr(pred) == ptr && - get_Load_mode(pred) == load_mode) { - /* - * a Load after a Load -- a read after read. - * We may remove the second Load, if it does not have an exception handler - * OR they are in the same block. In the later case the Load cannot - * throw an exception when the previous Load was quiet. - * - * Here, there is no need to check if the previous Load has an exception - * hander because they would have exact the same exception... - */ - if (! info->projs[pn_Load_X_except] || get_nodes_block(load) == get_nodes_block(pred)) { - ldst_info_t *pred_info = get_irn_link(pred); - - DBG_OPT_RAR(load, pred); - - if (pred_info->projs[pn_Load_res]) { - /* we need a data proj from the previous load for this optimization */ - if (info->projs[pn_Load_res]) - exchange(info->projs[pn_Load_res], pred_info->projs[pn_Load_res]); - - if (info->projs[pn_Load_M]) - exchange(info->projs[pn_Load_M], mem); - } - else { - if (info->projs[pn_Load_res]) { - set_Proj_pred(info->projs[pn_Load_res], pred); - set_nodes_block(info->projs[pn_Load_res], get_nodes_block(pred)); - pred_info->projs[pn_Load_res] = info->projs[pn_Load_res]; - } - if (info->projs[pn_Load_M]) { - /* Actually, this if should not be necessary. Construct the Loads - properly!!! */ - exchange(info->projs[pn_Load_M], mem); - } - } - - /* no exception */ - if (info->projs[pn_Load_X_except]) { - exchange(info->projs[pn_Load_X_except], new_Bad()); - res |= CF_CHANGED; - } - - return res |= DF_CHANGED; - } - } - - /* follow only Load chains */ - if (get_irn_op(pred) != op_Load) - break; - } - return res; -} + ldst_info_t *info = get_irn_link(load); + ir_node *mem, *ptr, *value; + ir_entity *ent; + long dummy; + unsigned res = 0; + + /* do NOT touch volatile loads for now */ + if (get_Load_volatility(load) == volatility_is_volatile) + return 0; + + /* the address of the load to be optimized */ + ptr = get_Load_ptr(load); + + /* + * Check if we can remove the exception from a Load: + * This can be done, if the address is from an Sel(Alloc) and + * the Sel type is a subtype of the allocated type. + * + * This optimizes some often used OO constructs, + * like x = new O; x->t; + */ + if (info->projs[pn_Load_X_except]) { + ir_node *addr = ptr; + + /* find base address */ + while (is_Sel(addr)) + addr = get_Sel_ptr(addr); + if (is_Alloc(skip_Proj(skip_Cast(addr)))) { + /* simple case: a direct load after an Alloc. Firm Alloc throw + * an exception in case of out-of-memory. So, there is no way for an + * exception in this load. + * This code is constructed by the "exception lowering" in the Jack compiler. + */ + exchange(info->projs[pn_Load_X_except], new_Bad()); + info->projs[pn_Load_X_except] = NULL; + exchange(info->projs[pn_Load_X_regular], new_r_Jmp(get_nodes_block(load))); + info->projs[pn_Load_X_regular] = NULL; + res |= CF_CHANGED; + } + } + + /* The mem of the Load. Must still be returned after optimization. */ + mem = get_Load_mem(load); + + if (! info->projs[pn_Load_res] && ! info->projs[pn_Load_X_except]) { + /* a Load which value is neither used nor exception checked, remove it */ + exchange(info->projs[pn_Load_M], mem); + + if (info->projs[pn_Load_X_regular]) { + /* should not happen, but if it does, remove it */ + exchange(info->projs[pn_Load_X_regular], new_r_Jmp(get_nodes_block(load))); + res |= CF_CHANGED; + } + kill_node(load); + reduce_adr_usage(ptr); + return res | DF_CHANGED; + } + + /* Load from a constant polymorphic field, where we can resolve + polymorphism. */ + value = transform_polymorph_Load(load); + if (value == load) { + value = NULL; + /* check if we can determine the entity that will be loaded */ + ent = find_constant_entity(ptr); + if (ent != NULL && + allocation_static == get_entity_allocation(ent) && + visibility_external_allocated != get_entity_visibility(ent)) { + /* a static allocation that is not external: there should be NO exception + * when loading even if we cannot replace the load itself. */ + + /* no exception, clear the info field as it might be checked later again */ + if (info->projs[pn_Load_X_except]) { + exchange(info->projs[pn_Load_X_except], new_Bad()); + info->projs[pn_Load_X_except] = NULL; + res |= CF_CHANGED; + } + if (info->projs[pn_Load_X_regular]) { + exchange(info->projs[pn_Load_X_regular], new_r_Jmp(get_nodes_block(load))); + info->projs[pn_Load_X_regular] = NULL; + res |= CF_CHANGED; + } + + if (variability_constant == get_entity_variability(ent)) { + if (is_atomic_entity(ent)) { + /* Might not be atomic after lowering of Sels. In this case we + * could also load, but it's more complicated. */ + /* more simpler case: we load the content of a constant value: + * replace it by the constant itself */ + value = get_atomic_ent_value(ent); + } else if (ent->has_initializer) { + /* new style initializer */ + value = find_compound_ent_value(ptr); + } else { + /* old style initializer */ + compound_graph_path *path = get_accessed_path(ptr); + + if (path != NULL) { + assert(is_proper_compound_graph_path(path, get_compound_graph_path_length(path)-1)); + + value = get_compound_ent_value_by_path(ent, path); + DB((dbg, LEVEL_1, " Constant access at %F%F resulted in %+F\n", ent, path, value)); + free_compound_graph_path(path); + } + } + if (value != NULL) + value = can_replace_load_by_const(load, value); + } + } + } + if (value != NULL) { + /* we completely replace the load by this value */ + if (info->projs[pn_Load_X_except]) { + exchange(info->projs[pn_Load_X_except], new_Bad()); + info->projs[pn_Load_X_except] = NULL; + res |= CF_CHANGED; + } + if (info->projs[pn_Load_X_regular]) { + exchange(info->projs[pn_Load_X_regular], new_r_Jmp(get_nodes_block(load))); + info->projs[pn_Load_X_regular] = NULL; + res |= CF_CHANGED; + } + if (info->projs[pn_Load_M]) { + exchange(info->projs[pn_Load_M], mem); + res |= DF_CHANGED; + } + if (info->projs[pn_Load_res]) { + exchange(info->projs[pn_Load_res], value); + res |= DF_CHANGED; + } + kill_node(load); + reduce_adr_usage(ptr); + return res; + } + + /* Check, if the address of this load is used more than once. + * If not, more load cannot be removed in any case. */ + if (get_irn_n_uses(ptr) <= 1 && get_irn_n_uses(get_base_and_offset(ptr, &dummy)) <= 1) + return res; + + /* + * follow the memory chain as long as there are only Loads + * and try to replace current Load or Store by a previous one. + * Note that in unreachable loops it might happen that we reach + * load again, as well as we can fall into a cycle. + * We break such cycles using a special visited flag. + */ + INC_MASTER(); + res = follow_Mem_chain(load, skip_Proj(mem)); + return res; +} /* optimize_load */ /** - * optimize a Store + * Check whether a value of mode new_mode would completely overwrite a value + * of mode old_mode in memory. + */ +static int is_completely_overwritten(ir_mode *old_mode, ir_mode *new_mode) +{ + return get_mode_size_bits(new_mode) >= get_mode_size_bits(old_mode); +} /* is_completely_overwritten */ + +/** + * Check whether small is a part of large (starting at same address). */ -static unsigned optimize_store(ir_node *store) +static int is_partially_same(ir_node *small, ir_node *large) { - ldst_info_t *info = get_irn_link(store); - ir_node *pred, *mem, *ptr, *value, *block; - ir_mode *mode; - unsigned res = 0; - - if (get_Store_volatility(store) == volatility_is_volatile) - return 0; - - /* - * BEWARE: one might think that checking the modes is useless, because - * if the pointers are identical, they refer to the same object. - * This is only true in strong typed languages, not is C were the following - * is possible *(type1 *)p = a; *(type2 *)p = b ... - */ - - ptr = get_Store_ptr(store); - - /* Check, if the address of this load is used more than once. - * If not, this load cannot be removed in any case. */ - if (get_irn_out_n(ptr) <= 1) - return 0; - - block = get_nodes_block(store); - mem = get_Store_mem(store); - value = get_Store_value(store); - mode = get_irn_mode(value); - - /* follow the memory chain as long as there are only Loads */ - for (pred = skip_Proj(mem); ; pred = skip_Proj(get_Load_mem(pred))) { - ldst_info_t *pred_info = get_irn_link(pred); - - if (get_irn_op(pred) == op_Store && get_Store_ptr(pred) == ptr && - get_nodes_block(pred) == block && get_irn_mode(get_Store_value(pred)) == mode) { - /* - * a Store after a Store in the same block -- a write after write. - * We may remove the first Store, if it does not have an exception handler. - * - * TODO: What, if both have the same exception handler ??? - */ - if (get_Store_volatility(pred) != volatility_is_volatile && !pred_info->projs[pn_Store_X_except]) { - DBG_OPT_WAW(pred, store); - exchange( pred_info->projs[pn_Store_M], get_Store_mem(pred) ); - return DF_CHANGED; - } - } - else if (get_irn_op(pred) == op_Load && get_Load_ptr(pred) == ptr && - value == pred_info->projs[pn_Load_res]) { - /* - * a Store of a value after a Load -- a write after read. - * We may remove the second Store, if it does not have an exception handler. - */ - if (! info->projs[pn_Store_X_except]) { - DBG_OPT_WAR(store, pred); - exchange( info->projs[pn_Store_M], mem ); - return DF_CHANGED; - } - } - - /* follow only Load chains */ - if (get_irn_op(pred) != op_Load) - break; - } - return res; + ir_mode *sm = get_irn_mode(small); + ir_mode *lm = get_irn_mode(large); + + /* FIXME: Check endianness */ + return is_Conv(small) && get_Conv_op(small) == large + && get_mode_size_bytes(sm) < get_mode_size_bytes(lm) + && get_mode_arithmetic(sm) == irma_twos_complement + && get_mode_arithmetic(lm) == irma_twos_complement; +} /* is_partially_same */ + +/** + * follow the memory chain as long as there are only Loads and alias free Stores. + * + * INC_MASTER() must be called before dive into + */ +static unsigned follow_Mem_chain_for_Store(ir_node *store, ir_node *curr) { + unsigned res = 0; + ldst_info_t *info = get_irn_link(store); + ir_node *pred; + ir_node *ptr = get_Store_ptr(store); + ir_node *mem = get_Store_mem(store); + ir_node *value = get_Store_value(store); + ir_mode *mode = get_irn_mode(value); + ir_node *block = get_nodes_block(store); + ir_node *mblk = get_Block_MacroBlock(block); + + for (pred = curr; pred != store;) { + ldst_info_t *pred_info = get_irn_link(pred); + + /* + * BEWARE: one might think that checking the modes is useless, because + * if the pointers are identical, they refer to the same object. + * This is only true in strong typed languages, not is C were the following + * is possible *(ir_type1 *)p = a; *(ir_type2 *)p = b ... + * However, if the size of the mode that is written is bigger or equal the + * size of the old one, the old value is completely overwritten and can be + * killed ... + */ + if (is_Store(pred) && get_Store_ptr(pred) == ptr && + get_nodes_MacroBlock(pred) == mblk) { + /* + * a Store after a Store in the same MacroBlock -- a write after write. + */ + + /* + * We may remove the first Store, if the old value is completely + * overwritten or the old value is a part of the new value, + * and if it does not have an exception handler. + * + * TODO: What, if both have the same exception handler ??? + */ + if (get_Store_volatility(pred) != volatility_is_volatile + && !pred_info->projs[pn_Store_X_except]) { + ir_node *predvalue = get_Store_value(pred); + ir_mode *predmode = get_irn_mode(predvalue); + + if(is_completely_overwritten(predmode, mode) + || is_partially_same(predvalue, value)) { + DBG_OPT_WAW(pred, store); + exchange(pred_info->projs[pn_Store_M], get_Store_mem(pred)); + kill_node(pred); + reduce_adr_usage(ptr); + return DF_CHANGED; + } + } + + /* + * We may remove the Store, if the old value already contains + * the new value, and if it does not have an exception handler. + * + * TODO: What, if both have the same exception handler ??? + */ + if (get_Store_volatility(store) != volatility_is_volatile + && !info->projs[pn_Store_X_except]) { + ir_node *predvalue = get_Store_value(pred); + + if(is_partially_same(value, predvalue)) { + DBG_OPT_WAW(pred, store); + exchange(info->projs[pn_Store_M], mem); + kill_node(store); + reduce_adr_usage(ptr); + return DF_CHANGED; + } + } + } else if (is_Load(pred) && get_Load_ptr(pred) == ptr && + value == pred_info->projs[pn_Load_res]) { + /* + * a Store of a value just loaded from the same address + * -- a write after read. + * We may remove the Store, if it does not have an exception + * handler. + */ + if (! info->projs[pn_Store_X_except]) { + DBG_OPT_WAR(store, pred); + exchange(info->projs[pn_Store_M], mem); + kill_node(store); + reduce_adr_usage(ptr); + return DF_CHANGED; + } + } + + if (is_Store(pred)) { + /* check if we can pass through this store */ + ir_alias_relation rel = get_alias_relation( + current_ir_graph, + get_Store_ptr(pred), + get_irn_mode(get_Store_value(pred)), + ptr, mode); + /* if the might be an alias, we cannot pass this Store */ + if (rel != ir_no_alias) + break; + pred = skip_Proj(get_Store_mem(pred)); + } else if (is_Load(pred)) { + ir_alias_relation rel = get_alias_relation( + current_ir_graph, get_Load_ptr(pred), get_Load_mode(pred), + ptr, mode); + if (rel != ir_no_alias) + break; + + pred = skip_Proj(get_Load_mem(pred)); + } else { + /* follow only Load chains */ + break; + } + + /* check for cycles */ + if (NODE_VISITED(pred_info)) + break; + MARK_NODE(pred_info); + } + + if (is_Sync(pred)) { + int i; + + /* handle all Sync predecessors */ + for (i = get_Sync_n_preds(pred) - 1; i >= 0; --i) { + res |= follow_Mem_chain_for_Store(store, skip_Proj(get_Sync_pred(pred, i))); + if (res) + break; + } + } + return res; +} /* follow_Mem_chain_for_Store */ + +/** find entity used as base for an address calculation */ +static ir_entity *find_entity(ir_node *ptr) +{ + switch(get_irn_opcode(ptr)) { + case iro_SymConst: + return get_SymConst_entity(ptr); + case iro_Sel: { + ir_node *pred = get_Sel_ptr(ptr); + if (get_irg_frame(get_irn_irg(ptr)) == pred) + return get_Sel_entity(ptr); + + return find_entity(pred); + } + case iro_Sub: + case iro_Add: { + ir_node *left = get_binop_left(ptr); + ir_node *right; + if (mode_is_reference(get_irn_mode(left))) + return find_entity(left); + right = get_binop_right(ptr); + if (mode_is_reference(get_irn_mode(right))) + return find_entity(right); + return NULL; + } + default: + return NULL; + } } /** - * walker, optimizes Phi after Stores: + * optimize a Store + * + * @param store the Store node + */ +static unsigned optimize_store(ir_node *store) { + ir_node *ptr; + ir_node *mem; + ir_entity *entity; + + if (get_Store_volatility(store) == volatility_is_volatile) + return 0; + + ptr = get_Store_ptr(store); + entity = find_entity(ptr); + + /* a store to an entity which is never read is unnecessary */ + if (entity != NULL && !(get_entity_usage(entity) & ir_usage_read)) { + ldst_info_t *info = get_irn_link(store); + if (info->projs[pn_Store_X_except] == NULL) { + DB((dbg, LEVEL_1, " Killing useless %+F to never read entity %+F\n", store, entity)); + exchange(info->projs[pn_Store_M], get_Store_mem(store)); + kill_node(store); + reduce_adr_usage(ptr); + return DF_CHANGED; + } + } + + /* Check, if the address of this Store is used more than once. + * If not, this Store cannot be removed in any case. */ + if (get_irn_n_uses(ptr) <= 1) + return 0; + + mem = get_Store_mem(store); + + /* follow the memory chain as long as there are only Loads */ + INC_MASTER(); + + return follow_Mem_chain_for_Store(store, skip_Proj(mem)); +} /* optimize_store */ + +/** + * walker, optimizes Phi after Stores to identical places: * Does the following optimization: + * @verbatim * * val1 val2 val3 val1 val2 val3 * | | | \ | / - * Str Str Str \ | / - * \ | / Phi + * Store Store Store \ | / + * \ | / PhiData * \ | / | - * \ | / Str - * Phi + * \ | / Store + * PhiM * + * @endverbatim * This reduces the number of stores and allows for predicated execution. * Moves Stores back to the end of a function which may be bad. * * This is only possible if the predecessor blocks have only one successor. */ -static unsigned optimize_phi(ir_node *phi, void *env) +static unsigned optimize_phi(ir_node *phi, walk_env_t *wenv) { - walk_env_t *wenv = env; - int i, n; - ir_node *store, *old_store, *ptr, *block, *phiM, *phiD, *exc, *projM; - ir_mode *mode; - ir_node **inM, **inD; - int *idx; - dbg_info *db = NULL; - ldst_info_t *info; - block_info_t *bl_info; - unsigned res = 0; - - /* Must be a memory Phi */ - if (get_irn_mode(phi) != mode_M) - return 0; - - n = get_Phi_n_preds(phi); - if (n <= 0) - return 0; - - store = skip_Proj(get_Phi_pred(phi, 0)); - old_store = store; - if (get_irn_op(store) != op_Store) - return 0; - - /* abort on dead blocks */ - if (is_Block_dead(get_nodes_block(store))) - return 0; - - /* check if the block has only one successor */ - bl_info = get_irn_link(get_nodes_block(store)); - if (bl_info->flags) - return 0; - - /* this is the address of the store */ - ptr = get_Store_ptr(store); - mode = get_irn_mode(get_Store_value(store)); - info = get_irn_link(store); - exc = info->exc_block; - - for (i = 1; i < n; ++i) { - ir_node *pred = skip_Proj(get_Phi_pred(phi, i)); - - if (get_irn_op(pred) != op_Store) - return 0; - - if (mode != get_irn_mode(get_Store_value(pred)) || ptr != get_Store_ptr(pred)) - return 0; - - info = get_irn_link(pred); - - /* check, if all stores have the same exception flow */ - if (exc != info->exc_block) - return 0; - - /* abort on dead blocks */ - if (is_Block_dead(get_nodes_block(store))) - return 0; - - /* check if the block has only one successor */ - bl_info = get_irn_link(get_nodes_block(store)); - if (bl_info->flags) - return 0; - } - - /* - * ok, when we are here, we found all predecessors of a Phi that - * are Stores to the same address. That means whatever we do before - * we enter the block of the Phi, we do a Store. - * So, we can move the store to the current block: - * - * val1 val2 val3 val1 val2 val3 - * | | | \ | / - * | Str | | Str | | Str | \ | / - * \ | / Phi - * \ | / | - * \ | / Str - * Phi - * - * Is only allowed if the predecessor blocks have only one successor. - */ - - /* first step: collect all inputs */ - NEW_ARR_A(ir_node *, inM, n); - NEW_ARR_A(ir_node *, inD, n); - NEW_ARR_A(int, idx, n); - - for (i = 0; i < n; ++i) { - ir_node *pred = skip_Proj(get_Phi_pred(phi, i)); - info = get_irn_link(pred); - - inM[i] = get_Store_mem(pred); - inD[i] = get_Store_value(pred); - idx[i] = info->exc_idx; - } - block = get_nodes_block(phi); - - /* second step: create a new memory Phi */ - phiM = new_rd_Phi(get_irn_dbg_info(phi), current_ir_graph, block, n, inM, mode_M); - - /* third step: create a new data Phi */ - phiD = new_rd_Phi(get_irn_dbg_info(phi), current_ir_graph, block, n, inD, mode); - - /* fourth step: create the Store */ - store = new_rd_Store(db, current_ir_graph, block, phiM, ptr, phiD); + int i, n; + ir_node *store, *old_store, *ptr, *block, *phi_block, *phiM, *phiD, *exc, *projM; + ir_mode *mode; + ir_node **inM, **inD, **projMs; + int *idx; + dbg_info *db = NULL; + ldst_info_t *info; + block_info_t *bl_info; + unsigned res = 0; + + /* Must be a memory Phi */ + if (get_irn_mode(phi) != mode_M) + return 0; + + n = get_Phi_n_preds(phi); + if (n <= 0) + return 0; + + /* must be only one user */ + projM = get_Phi_pred(phi, 0); + if (get_irn_n_edges(projM) != 1) + return 0; + + store = skip_Proj(projM); + old_store = store; + if (!is_Store(store)) + return 0; + + block = get_nodes_block(store); + + /* abort on dead blocks */ + if (is_Block_dead(block)) + return 0; + + /* check if the block is post dominated by Phi-block + and has no exception exit */ + bl_info = get_irn_link(block); + if (bl_info->flags & BLOCK_HAS_EXC) + return 0; + + phi_block = get_nodes_block(phi); + if (! block_strictly_postdominates(phi_block, block)) + return 0; + + /* this is the address of the store */ + ptr = get_Store_ptr(store); + mode = get_irn_mode(get_Store_value(store)); + info = get_irn_link(store); + exc = info->exc_block; + + for (i = 1; i < n; ++i) { + ir_node *pred = get_Phi_pred(phi, i); + + if (get_irn_n_edges(pred) != 1) + return 0; + + pred = skip_Proj(pred); + if (!is_Store(pred)) + return 0; + + if (ptr != get_Store_ptr(pred) || mode != get_irn_mode(get_Store_value(pred))) + return 0; + + info = get_irn_link(pred); + + /* check, if all stores have the same exception flow */ + if (exc != info->exc_block) + return 0; + + /* abort on dead blocks */ + block = get_nodes_block(pred); + if (is_Block_dead(block)) + return 0; + + /* check if the block is post dominated by Phi-block + and has no exception exit. Note that block must be different from + Phi-block, else we would move a Store from end End of a block to its + Start... */ + bl_info = get_irn_link(block); + if (bl_info->flags & BLOCK_HAS_EXC) + return 0; + if (block == phi_block || ! block_postdominates(phi_block, block)) + return 0; + } + + /* + * ok, when we are here, we found all predecessors of a Phi that + * are Stores to the same address and size. That means whatever + * we do before we enter the block of the Phi, we do a Store. + * So, we can move the Store to the current block: + * + * val1 val2 val3 val1 val2 val3 + * | | | \ | / + * | Str | | Str | | Str | \ | / + * \ | / PhiData + * \ | / | + * \ | / Str + * PhiM + * + * Is only allowed if the predecessor blocks have only one successor. + */ + + NEW_ARR_A(ir_node *, projMs, n); + NEW_ARR_A(ir_node *, inM, n); + NEW_ARR_A(ir_node *, inD, n); + NEW_ARR_A(int, idx, n); + + /* Prepare: Collect all Store nodes. We must do this + first because we otherwise may loose a store when exchanging its + memory Proj. + */ + for (i = n - 1; i >= 0; --i) { + ir_node *store; + + projMs[i] = get_Phi_pred(phi, i); + assert(is_Proj(projMs[i])); + + store = get_Proj_pred(projMs[i]); + info = get_irn_link(store); + + inM[i] = get_Store_mem(store); + inD[i] = get_Store_value(store); + idx[i] = info->exc_idx; + } + block = get_nodes_block(phi); + + /* second step: create a new memory Phi */ + phiM = new_rd_Phi(get_irn_dbg_info(phi), block, n, inM, mode_M); + + /* third step: create a new data Phi */ + phiD = new_rd_Phi(get_irn_dbg_info(phi), block, n, inD, mode); + + /* rewire memory and kill the node */ + for (i = n - 1; i >= 0; --i) { + ir_node *proj = projMs[i]; + + if(is_Proj(proj)) { + ir_node *store = get_Proj_pred(proj); + exchange(proj, inM[i]); + kill_node(store); + } + } + + /* fourth step: create the Store */ + store = new_rd_Store(db, block, phiM, ptr, phiD, 0); #ifdef DO_CACHEOPT - co_set_irn_name(store, co_get_irn_ident(old_store)); + co_set_irn_name(store, co_get_irn_ident(old_store)); #endif - projM = new_rd_Proj(NULL, current_ir_graph, block, store, mode_M, pn_Store_M); + projM = new_rd_Proj(NULL, block, store, mode_M, pn_Store_M); - info = get_ldst_info(store, wenv); - info->projs[pn_Store_M] = projM; + info = get_ldst_info(store, &wenv->obst); + info->projs[pn_Store_M] = projM; - /* fifths step: repair exception flow */ - if (exc) { - ir_node *projX = new_rd_Proj(NULL, current_ir_graph, block, store, mode_X, pn_Store_X_except); + /* fifths step: repair exception flow */ + if (exc) { + ir_node *projX = new_rd_Proj(NULL, block, store, mode_X, pn_Store_X_except); - info->projs[pn_Store_X_except] = projX; - info->exc_block = exc; - info->exc_idx = idx[0]; + info->projs[pn_Store_X_except] = projX; + info->exc_block = exc; + info->exc_idx = idx[0]; - for (i = 0; i < n; ++i) { - set_Block_cfgpred(exc, idx[i], projX); - } + for (i = 0; i < n; ++i) { + set_Block_cfgpred(exc, idx[i], projX); + } - if (n > 1) { - /* the exception block should be optimized as some inputs are identical now */ - } + if (n > 1) { + /* the exception block should be optimized as some inputs are identical now */ + } - res |= CF_CHANGED; - } + res |= CF_CHANGED; + } - /* sixth step: replace old Phi */ - exchange(phi, projM); + /* sixth step: replace old Phi */ + exchange(phi, projM); - return res | DF_CHANGED; -} + return res | DF_CHANGED; +} /* optimize_phi */ /** - * walker, collects all Load/Store/Proj nodes + * walker, do the optimizations + */ +static void do_load_store_optimize(ir_node *n, void *env) { + walk_env_t *wenv = env; + + switch (get_irn_opcode(n)) { + + case iro_Load: + wenv->changes |= optimize_load(n); + break; + + case iro_Store: + wenv->changes |= optimize_store(n); + break; + + case iro_Phi: + wenv->changes |= optimize_phi(n, wenv); + break; + + default: + ; + } +} /* do_load_store_optimize */ + +/** A scc. */ +typedef struct scc { + ir_node *head; /**< the head of the list */ +} scc; + +/** A node entry. */ +typedef struct node_entry { + unsigned DFSnum; /**< the DFS number of this node */ + unsigned low; /**< the low number of this node */ + int in_stack; /**< flag, set if the node is on the stack */ + ir_node *next; /**< link to the next node the the same scc */ + scc *pscc; /**< the scc of this node */ + unsigned POnum; /**< the post order number for blocks */ +} node_entry; + +/** A loop entry. */ +typedef struct loop_env { + ir_phase ph; /**< the phase object */ + ir_node **stack; /**< the node stack */ + int tos; /**< tos index */ + unsigned nextDFSnum; /**< the current DFS number */ + unsigned POnum; /**< current post order number */ + + unsigned changes; /**< a bitmask of graph changes */ +} loop_env; + +/** +* Gets the node_entry of a node +*/ +static node_entry *get_irn_ne(ir_node *irn, loop_env *env) { + ir_phase *ph = &env->ph; + node_entry *e = phase_get_irn_data(&env->ph, irn); + + if (! e) { + e = phase_alloc(ph, sizeof(*e)); + memset(e, 0, sizeof(*e)); + phase_set_irn_data(ph, irn, e); + } + return e; +} /* get_irn_ne */ + +/** + * Push a node onto the stack. + * + * @param env the loop environment + * @param n the node to push + */ +static void push(loop_env *env, ir_node *n) { + node_entry *e; + + if (env->tos == ARR_LEN(env->stack)) { + int nlen = ARR_LEN(env->stack) * 2; + ARR_RESIZE(ir_node *, env->stack, nlen); + } + env->stack[env->tos++] = n; + e = get_irn_ne(n, env); + e->in_stack = 1; +} /* push */ + +/** + * pop a node from the stack + * + * @param env the loop environment + * + * @return The topmost node + */ +static ir_node *pop(loop_env *env) { + ir_node *n = env->stack[--env->tos]; + node_entry *e = get_irn_ne(n, env); + + e->in_stack = 0; + return n; +} /* pop */ + +/** + * Check if irn is a region constant. + * The block or irn must strictly dominate the header block. + * + * @param irn the node to check + * @param header_block the header block of the induction variable + */ +static int is_rc(ir_node *irn, ir_node *header_block) { + ir_node *block = get_nodes_block(irn); + + return (block != header_block) && block_dominates(block, header_block); +} /* is_rc */ + +typedef struct phi_entry phi_entry; +struct phi_entry { + ir_node *phi; /**< A phi with a region const memory. */ + int pos; /**< The position of the region const memory */ + ir_node *load; /**< the newly created load for this phi */ + phi_entry *next; +}; + +/** + * An entry in the avail set. + */ +typedef struct avail_entry_t { + ir_node *ptr; /**< the address pointer */ + ir_mode *mode; /**< the load mode */ + ir_node *load; /**< the associated Load */ +} avail_entry_t; + +/** + * Compare two avail entries. + */ +static int cmp_avail_entry(const void *elt, const void *key, size_t size) { + const avail_entry_t *a = elt; + const avail_entry_t *b = key; + (void) size; + + return a->ptr != b->ptr || a->mode != b->mode; +} /* cmp_avail_entry */ + +/** + * Calculate the hash value of an avail entry. + */ +static unsigned hash_cache_entry(const avail_entry_t *entry) { + return get_irn_idx(entry->ptr) * 9 + HASH_PTR(entry->mode); +} /* hash_cache_entry */ + +/** + * Move loops out of loops if possible. + * + * @param pscc the loop described by an SCC + * @param env the loop environment */ -static void do_load_store_optimize(ir_node *n, void *env) +static void move_loads_out_of_loops(scc *pscc, loop_env *env) { + ir_node *phi, *load, *next, *other, *next_other; + ir_entity *ent; + int j; + phi_entry *phi_list = NULL; + set *avail; + + avail = new_set(cmp_avail_entry, 8); + + /* collect all outer memories */ + for (phi = pscc->head; phi != NULL; phi = next) { + node_entry *ne = get_irn_ne(phi, env); + next = ne->next; + + /* check all memory Phi's */ + if (! is_Phi(phi)) + continue; + + assert(get_irn_mode(phi) == mode_M && "DFS return non-memory Phi"); + + for (j = get_irn_arity(phi) - 1; j >= 0; --j) { + ir_node *pred = get_irn_n(phi, j); + node_entry *pe = get_irn_ne(pred, env); + + if (pe->pscc != ne->pscc) { + /* not in the same SCC, is region const */ + phi_entry *pe = phase_alloc(&env->ph, sizeof(*pe)); + + pe->phi = phi; + pe->pos = j; + pe->next = phi_list; + phi_list = pe; + } + } + } + /* no Phis no fun */ + assert(phi_list != NULL && "DFS found a loop without Phi"); + + /* for now, we cannot handle more than one input (only reducible cf) */ + if (phi_list->next != NULL) + return; + + for (load = pscc->head; load; load = next) { + ir_mode *load_mode; + node_entry *ne = get_irn_ne(load, env); + next = ne->next; + + if (is_Load(load)) { + ldst_info_t *info = get_irn_link(load); + ir_node *ptr = get_Load_ptr(load); + + /* for now, we cannot handle Loads with exceptions */ + if (info->projs[pn_Load_res] == NULL || info->projs[pn_Load_X_regular] != NULL || info->projs[pn_Load_X_except] != NULL) + continue; + + /* for now, we can only move Load(Global) */ + if (! is_Global(ptr)) + continue; + ent = get_Global_entity(ptr); + load_mode = get_Load_mode(load); + for (other = pscc->head; other != NULL; other = next_other) { + node_entry *ne = get_irn_ne(other, env); + next_other = ne->next; + + if (is_Store(other)) { + ir_alias_relation rel = get_alias_relation( + current_ir_graph, + get_Store_ptr(other), + get_irn_mode(get_Store_value(other)), + ptr, load_mode); + /* if the might be an alias, we cannot pass this Store */ + if (rel != ir_no_alias) + break; + } + /* only Phis and pure Calls are allowed here, so ignore them */ + } + if (other == NULL) { + ldst_info_t *ninfo; + phi_entry *pe; + dbg_info *db; + + /* yep, no aliasing Store found, Load can be moved */ + DB((dbg, LEVEL_1, " Found a Load that could be moved: %+F\n", load)); + + db = get_irn_dbg_info(load); + for (pe = phi_list; pe != NULL; pe = pe->next) { + int pos = pe->pos; + ir_node *phi = pe->phi; + ir_node *blk = get_nodes_block(phi); + ir_node *pred = get_Block_cfgpred_block(blk, pos); + ir_node *irn, *mem; + avail_entry_t entry, *res; + + entry.ptr = ptr; + entry.mode = load_mode; + res = set_find(avail, &entry, sizeof(entry), hash_cache_entry(&entry)); + if (res != NULL) { + irn = res->load; + } else { + irn = new_rd_Load(db, pred, get_Phi_pred(phi, pos), ptr, load_mode, 0); + entry.load = irn; + set_insert(avail, &entry, sizeof(entry), hash_cache_entry(&entry)); + DB((dbg, LEVEL_1, " Created %+F in %+F\n", irn, pred)); + } + pe->load = irn; + ninfo = get_ldst_info(irn, phase_obst(&env->ph)); + + ninfo->projs[pn_Load_M] = mem = new_r_Proj(pred, irn, mode_M, pn_Load_M); + set_Phi_pred(phi, pos, mem); + + ninfo->projs[pn_Load_res] = new_r_Proj(pred, irn, load_mode, pn_Load_res); + } + + /* now kill the old Load */ + exchange(info->projs[pn_Load_M], get_Load_mem(load)); + exchange(info->projs[pn_Load_res], ninfo->projs[pn_Load_res]); + + env->changes |= DF_CHANGED; + } + } + } + del_set(avail); +} /* move_loads_out_of_loops */ + +/** + * Process a loop SCC. + * + * @param pscc the SCC + * @param env the loop environment + */ +static void process_loop(scc *pscc, loop_env *env) { + ir_node *irn, *next, *header = NULL; + node_entry *b, *h = NULL; + int j, only_phi, num_outside, process = 0; + ir_node *out_rc; + + /* find the header block for this scc */ + for (irn = pscc->head; irn; irn = next) { + node_entry *e = get_irn_ne(irn, env); + ir_node *block = get_nodes_block(irn); + + next = e->next; + b = get_irn_ne(block, env); + + if (header != NULL) { + if (h->POnum < b->POnum) { + header = block; + h = b; + } + } else { + header = block; + h = b; + } + } + + /* check if this scc contains only Phi, Loads or Stores nodes */ + only_phi = 1; + num_outside = 0; + out_rc = NULL; + for (irn = pscc->head; irn; irn = next) { + node_entry *e = get_irn_ne(irn, env); + + next = e->next; + switch (get_irn_opcode(irn)) { + case iro_Call: + if (is_Call_pure(irn)) { + /* pure calls can be treated like loads */ + only_phi = 0; + break; + } + /* non-pure calls must be handle like may-alias Stores */ + goto fail; + case iro_CopyB: + /* cannot handle CopyB yet */ + goto fail; + case iro_Load: + process = 1; + if (get_Load_volatility(irn) == volatility_is_volatile) { + /* cannot handle loops with volatile Loads */ + goto fail; + } + only_phi = 0; + break; + case iro_Store: + if (get_Store_volatility(irn) == volatility_is_volatile) { + /* cannot handle loops with volatile Stores */ + goto fail; + } + only_phi = 0; + break; + default: + only_phi = 0; + break; + case iro_Phi: + for (j = get_irn_arity(irn) - 1; j >= 0; --j) { + ir_node *pred = get_irn_n(irn, j); + node_entry *pe = get_irn_ne(pred, env); + + if (pe->pscc != e->pscc) { + /* not in the same SCC, must be a region const */ + if (! is_rc(pred, header)) { + /* not a memory loop */ + goto fail; + } + if (out_rc == NULL) { + /* first region constant */ + out_rc = pred; + ++num_outside; + } else if (out_rc != pred) { + /* another region constant */ + ++num_outside; + } + } + } + break; + } + } + if (! process) + goto fail; + + /* found a memory loop */ + DB((dbg, LEVEL_2, " Found a memory loop:\n ")); + if (only_phi && num_outside == 1) { + /* a phi cycle with only one real predecessor can be collapsed */ + DB((dbg, LEVEL_2, " Found an USELESS Phi cycle:\n ")); + + for (irn = pscc->head; irn; irn = next) { + node_entry *e = get_irn_ne(irn, env); + next = e->next; + exchange(irn, out_rc); + } + env->changes |= DF_CHANGED; + return; + } + +#ifdef DEBUG_libfirm + for (irn = pscc->head; irn; irn = next) { + node_entry *e = get_irn_ne(irn, env); + next = e->next; + DB((dbg, LEVEL_2, " %+F,", irn)); + } + DB((dbg, LEVEL_2, "\n")); +#endif + move_loads_out_of_loops(pscc, env); + +fail: + ; +} /* process_loop */ + +/** + * Process a SCC. + * + * @param pscc the SCC + * @param env the loop environment + */ +static void process_scc(scc *pscc, loop_env *env) { + ir_node *head = pscc->head; + node_entry *e = get_irn_ne(head, env); + +#ifdef DEBUG_libfirm + { + ir_node *irn, *next; + + DB((dbg, LEVEL_4, " SCC at %p:\n ", pscc)); + for (irn = pscc->head; irn; irn = next) { + node_entry *e = get_irn_ne(irn, env); + + next = e->next; + + DB((dbg, LEVEL_4, " %+F,", irn)); + } + DB((dbg, LEVEL_4, "\n")); + } +#endif + + if (e->next != NULL) { + /* this SCC has more than one member */ + process_loop(pscc, env); + } +} /* process_scc */ + +/** + * Do Tarjan's SCC algorithm and drive load/store optimization. + * + * @param irn start at this node + * @param env the loop environment + */ +static void dfs(ir_node *irn, loop_env *env) { - walk_env_t *wenv = env; + int i, n; + node_entry *node = get_irn_ne(irn, env); + + mark_irn_visited(irn); + + node->DFSnum = env->nextDFSnum++; + node->low = node->DFSnum; + push(env, irn); + + /* handle preds */ + if (is_Phi(irn) || is_Sync(irn)) { + n = get_irn_arity(irn); + for (i = 0; i < n; ++i) { + ir_node *pred = get_irn_n(irn, i); + node_entry *o = get_irn_ne(pred, env); + + if (!irn_visited(pred)) { + dfs(pred, env); + node->low = MIN(node->low, o->low); + } + if (o->DFSnum < node->DFSnum && o->in_stack) + node->low = MIN(o->DFSnum, node->low); + } + } else if (is_fragile_op(irn)) { + ir_node *pred = get_fragile_op_mem(irn); + node_entry *o = get_irn_ne(pred, env); + + if (!irn_visited(pred)) { + dfs(pred, env); + node->low = MIN(node->low, o->low); + } + if (o->DFSnum < node->DFSnum && o->in_stack) + node->low = MIN(o->DFSnum, node->low); + } else if (is_Proj(irn)) { + ir_node *pred = get_Proj_pred(irn); + node_entry *o = get_irn_ne(pred, env); + + if (!irn_visited(pred)) { + dfs(pred, env); + node->low = MIN(node->low, o->low); + } + if (o->DFSnum < node->DFSnum && o->in_stack) + node->low = MIN(o->DFSnum, node->low); + } + else { + /* IGNORE predecessors */ + } + + if (node->low == node->DFSnum) { + scc *pscc = phase_alloc(&env->ph, sizeof(*pscc)); + ir_node *x; + + pscc->head = NULL; + do { + node_entry *e; + + x = pop(env); + e = get_irn_ne(x, env); + e->pscc = pscc; + e->next = pscc->head; + pscc->head = x; + } while (x != irn); + + process_scc(pscc, env); + } +} /* dfs */ - switch (get_irn_opcode(n)) { +/** + * Do the DFS on the memory edges a graph. + * + * @param irg the graph to process + * @param env the loop environment + */ +static void do_dfs(ir_graph *irg, loop_env *env) { + ir_graph *rem = current_ir_graph; + ir_node *endblk, *end; + int i; + + current_ir_graph = irg; + inc_irg_visited(irg); + + /* visit all memory nodes */ + endblk = get_irg_end_block(irg); + for (i = get_Block_n_cfgpreds(endblk) - 1; i >= 0; --i) { + ir_node *pred = get_Block_cfgpred(endblk, i); + + pred = skip_Proj(pred); + if (is_Return(pred)) + dfs(get_Return_mem(pred), env); + else if (is_Raise(pred)) + dfs(get_Raise_mem(pred), env); + else if (is_fragile_op(pred)) + dfs(get_fragile_op_mem(pred), env); + else { + assert(0 && "Unknown EndBlock predecessor"); + } + } + + /* visit the keep-alives */ + end = get_irg_end(irg); + for (i = get_End_n_keepalives(end) - 1; i >= 0; --i) { + ir_node *ka = get_End_keepalive(end, i); + + if (is_Phi(ka) && !irn_visited(ka)) + dfs(ka, env); + } + current_ir_graph = rem; +} /* do_dfs */ + +/** + * Initialize new phase data. We do this always explicit, so return NULL here + */ +static void *init_loop_data(ir_phase *ph, const ir_node *irn, void *data) { + (void)ph; + (void)irn; + (void)data; + return NULL; +} /* init_loop_data */ - case iro_Load: - wenv->changes |= optimize_load(n); - break; +/** + * Optimize Loads/Stores in loops. + * + * @param irg the graph + */ +static int optimize_loops(ir_graph *irg) { + loop_env env; - case iro_Store: - wenv->changes |= optimize_store(n); - break; + env.stack = NEW_ARR_F(ir_node *, 128); + env.tos = 0; + env.nextDFSnum = 0; + env.POnum = 0; + env.changes = 0; + phase_init(&env.ph, "ldstopt", irg, PHASE_DEFAULT_GROWTH, init_loop_data, NULL); - case iro_Phi: - wenv->changes |= optimize_phi(n, env); + /* calculate the SCC's and drive loop optimization. */ + do_dfs(irg, &env); - default: - ; - } -} + DEL_ARR_F(env.stack); + phase_free(&env.ph); + + return env.changes; +} /* optimize_loops */ /* * do the load store optimization */ -void optimize_load_store(ir_graph *irg) -{ - walk_env_t env; +int optimize_load_store(ir_graph *irg) { + walk_env_t env; - assert(get_irg_phase_state(irg) != phase_building); - assert(get_irg_pinned(irg) != op_pin_state_floats && - "LoadStore optimization needs pinned graph"); + FIRM_DBG_REGISTER(dbg, "firm.opt.ldstopt"); - if (!get_opt_redundant_LoadStore()) - return; + assert(get_irg_phase_state(irg) != phase_building); + assert(get_irg_pinned(irg) != op_pin_state_floats && + "LoadStore optimization needs pinned graph"); - obstack_init(&env.obst); - env.changes = 0; + /* we need landing pads */ + remove_critical_cf_edges(irg); - /* init the links, then collect Loads/Stores/Proj's in lists */ - irg_walk_graph(irg, firm_clear_link, collect_nodes, &env); + edges_assure(irg); - /* now we have collected enough information, optimize */ - irg_walk_graph(irg, NULL, do_load_store_optimize, &env); + /* for Phi optimization post-dominators are needed ... */ + assure_postdoms(irg); - obstack_free(&env.obst, NULL); + if (get_opt_alias_analysis()) { + assure_irg_entity_usage_computed(irg); + assure_irp_globals_entity_usage_computed(); + } - /* Handle graph state */ - if (env.changes) { - if (get_irg_outs_state(current_ir_graph) == outs_consistent) - set_irg_outs_inconsistent(current_ir_graph); - } + obstack_init(&env.obst); + env.changes = 0; - if (env.changes & CF_CHANGED) { - /* is this really needed: Yes, control flow changed, block might get Bad. */ - if (get_irg_dom_state(current_ir_graph) == dom_consistent) - set_irg_dom_inconsistent(current_ir_graph); - } -} + /* init the links, then collect Loads/Stores/Proj's in lists */ + master_visited = 0; + irg_walk_graph(irg, firm_clear_link, collect_nodes, &env); + + /* now we have collected enough information, optimize */ + irg_walk_graph(irg, NULL, do_load_store_optimize, &env); + + env.changes |= optimize_loops(irg); + + obstack_free(&env.obst, NULL); + + /* Handle graph state */ + if (env.changes) { + set_irg_outs_inconsistent(irg); + set_irg_entity_usage_state(irg, ir_entity_usage_not_computed); + } + + if (env.changes & CF_CHANGED) { + /* is this really needed: Yes, control flow changed, block might + have Bad() predecessors. */ + set_irg_doms_inconsistent(irg); + } + return env.changes != 0; +} /* optimize_load_store */ + +ir_graph_pass_t *optimize_load_store_pass(const char *name, int verify, int dump) +{ + return def_graph_pass(name ? name : "ldst", verify, dump, optimize_load_store); +} /* optimize_load_store_pass */