X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fopt%2Fldstopt.c;h=c8b58f58e06127c61e593657257367548bcc03ce;hb=f1a1a6092d9e4ebd9e22dd1c57d76ef8aeda74fc;hp=043a3b2a3b0e1a3d044054738dfa598639dd7f1d;hpb=e11232be68a7fbe13e49ec3be0a51a779c1cc435;p=libfirm diff --git a/ir/opt/ldstopt.c b/ir/opt/ldstopt.c index 043a3b2a3..c8b58f58e 100644 --- a/ir/opt/ldstopt.c +++ b/ir/opt/ldstopt.c @@ -255,12 +255,12 @@ static entity *find_constant_entity(ir_node *ptr) /* 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; + ((get_entity_n_overwrites(ent) != 0) || + (get_entity_n_overwrittenby(ent) != 0) ) ) + return NULL; if (variability_constant == get_entity_variability(ent)) - return ent; + return ent; if (is_Array_type(tp)) { /* check bounds */ @@ -301,28 +301,48 @@ static entity *find_constant_entity(ir_node *ptr) } } +/** + * 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)); } +/** + * Returns the accessed component graph path for an + * node computing an address. + * + * @param ptr the node computing the address + * @param depth current depth in steps upward from the root + * of the address + */ static compound_graph_path *rec_get_accessed_path(ir_node *ptr, int depth) { - compound_graph_path *res; + 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); - entity *root = get_SymConst_entity(ptr); - if (depth == 0) - res = NULL; - else - res = new_compound_graph_path(get_entity_type(root), depth); - } else { + 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); - entity *field = get_Sel_entity(ptr); - int path_len = get_compound_graph_path_length(res); - int pos = path_len - 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)); @@ -331,14 +351,13 @@ static compound_graph_path *rec_get_accessed_path(ir_node *ptr, int depth) { return res; } - /** 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. */ + * 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); } - /** * optimize a Load */ @@ -346,17 +365,21 @@ static int 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; + ir_node *pred, *mem, *ptr, *new_node; entity *ent; int 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 form a Load: - * this can be done, if the address is from an Sel(Alloc) and - * the Sel type is a subtype of the alloc type. + * 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; @@ -365,7 +388,7 @@ static int optimize_load(ir_node *load) if (get_irn_op(ptr) == op_Sel) { ir_node *mem = get_Sel_mem(ptr); - if (get_irn_op(mem) == op_Alloc) { + 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); @@ -373,14 +396,16 @@ static int optimize_load(ir_node *load) 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 */ + * Alloc guarantees that enough memory was allocated */ exchange(info->projs[pn_Load_X_except], new_Bad()); info->projs[pn_Load_X_except] = NULL; + res = 1; } } } - else if (get_irn_op(ptr) == op_Alloc) { + 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. @@ -388,27 +413,23 @@ static int optimize_load(ir_node *load) */ exchange(info->projs[pn_Load_X_except], new_Bad()); info->projs[pn_Load_X_except] = NULL; + res = 1; } } - /* do NOT touch volatile loads for now */ - if (get_Load_volatility(load) == volatility_is_volatile) - return 0; + /* 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 */ - mem = get_Load_mem(load); exchange(info->projs[pn_Load_M], mem); return 1; } - /* the mem of the Load. Must still be returned after optimization */ - mem = get_Load_mem(load); - /* Load from a constant polymorphic field, where we can resolve polymorphy. */ - ir_node *new_node = transform_node_Load(load); + new_node = transform_node_Load(load); if (new_node != load) { if (info->projs[pn_Load_M]) { exchange(info->projs[pn_Load_M], mem); @@ -435,20 +456,24 @@ static int optimize_load(ir_node *load) if (info->projs[pn_Load_X_except]) { exchange(info->projs[pn_Load_X_except], new_Bad()); info->projs[pn_Load_X_except] = NULL; + res = 1; } 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. */ + && 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]) + if (info->projs[pn_Load_M]) { exchange(info->projs[pn_Load_M], mem); + res = 1; + } /* no result :-) */ if (info->projs[pn_Load_res]) { @@ -457,63 +482,71 @@ static int optimize_load(ir_node *load) DBG_OPT_RC(load, c); exchange(info->projs[pn_Load_res], c); - return 1; } } } else if (variability_constant == get_entity_variability(ent)) { - 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); - - compound_graph_path *path = get_accessed_path(ptr); - if (path) { - assert(is_proper_compound_graph_path(path, get_compound_graph_path_length(path)-1)); - ir_node *c = get_compound_ent_value_by_path(ent, path); - - printf(" cons: "); DDMN(c); - - if (info->projs[pn_Load_M]) - exchange(info->projs[pn_Load_M], mem); - if (info->projs[pn_Load_res]) - exchange(info->projs[pn_Load_res], copy_const_value(c)); - - { - 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"); - } - } else { - printf("cannot optimize.\n"); - } - } + 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"); + } + */ - /* we changed the irg, but try further */ - res = 1; - } + 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 = 1; + } + if (info->projs[pn_Load_res]) { + exchange(info->projs[pn_Load_res], copy_const_value(c)); + return 1; + } + } + 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 0; + return res; - /* follow the memory chain as long as there are only Loads */ + /* 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 is C were the following + * This is only true in strong typed languages, not in C were the following * is possible a = *(type1 *)p; b = *(type2 *)p ... */ @@ -527,22 +560,27 @@ static int optimize_load(ir_node *load) * 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 Exc? If the Store cannot be executed (ROM) - * the exception handler might simply jump into the load block :-( + * 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)) { - DBG_OPT_RAW(load, pred); - exchange( info->projs[pn_Load_res], get_Store_value(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()); + + if (info->projs[pn_Load_res]) + exchange(info->projs[pn_Load_res], value); + return 1; } } @@ -554,8 +592,8 @@ static int optimize_load(ir_node *load) * 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 previos Load has an exception hander because - * they would have exact the same exception... + * 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); @@ -564,7 +602,9 @@ static int optimize_load(ir_node *load) if (pred_info->projs[pn_Load_res]) { /* we need a data proj from the previous load for this optimization */ - exchange( info->projs[pn_Load_res], pred_info->projs[pn_Load_res] ); + 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); } @@ -572,6 +612,7 @@ static int optimize_load(ir_node *load) 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 @@ -852,6 +893,8 @@ void 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"); if (!get_opt_redundant_LoadStore()) return;