X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;ds=sidebyside;f=ir%2Fopt%2Fldstopt.c;h=91347a7bea9076376bfdfabd3af816ae9dc332fa;hb=44faeb9742640d3498eb4482f98eb1255607c4d6;hp=58b24ec54e9b7b7d9445c5a4a7d4ae9745884ab6;hpb=4b01bfe0d5adc5f4d03d4b4491dc7cb928301d3f;p=libfirm

diff --git a/ir/opt/ldstopt.c b/ir/opt/ldstopt.c
index 58b24ec54..91347a7be 100644
--- a/ir/opt/ldstopt.c
+++ b/ir/opt/ldstopt.c
@@ -386,11 +386,12 @@ static compound_graph_path *rec_get_accessed_path(ir_node *ptr, int depth) {
 			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;
+		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)) {
+		if (is_Const(r) && get_irn_mode(l) == mode) {
 			ptr = l;
 			tv  = get_Const_tarval(r);
 		} else {
@@ -399,6 +400,7 @@ static compound_graph_path *rec_get_accessed_path(ir_node *ptr, int depth) {
 		}
 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)) {
@@ -419,10 +421,10 @@ ptr_arith:
 			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);
+			tv_index = tarval_div(tmp, sz);
+			tmp      = tarval_mod(tmp, sz);
 
-			if (tv_index == tarval_bad || tv == tarval_bad)
+			if (tv_index == tarval_bad || tmp == tarval_bad)
 				return NULL;
 
 			assert(get_array_n_dimensions(tp) == 1 && "multiarrays not implemented");
@@ -442,7 +444,7 @@ ptr_arith:
 			/* ok, bounds check finished */
 			++idx;
 		}
-		if (! tarval_is_null(tv)) {
+		if (! tarval_is_null(tmp)) {
 			/* access to some struct/union member */
 			return NULL;
 		}
@@ -500,7 +502,8 @@ ptr_arith:
  * 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 {
@@ -538,7 +541,7 @@ static ir_node *rec_find_compound_ent_value(ir_node *ptr, path_entry *next) {
 					continue;
 				}
 			}
-			if (p->index >= n)
+			if (p->index >= (int) n)
 				return NULL;
 			initializer = get_initializer_compound_value(initializer, p->index);
 
@@ -1188,6 +1191,7 @@ static unsigned optimize_load(ir_node *load)
 								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);
 							}
 						}
@@ -1352,18 +1356,61 @@ static unsigned follow_Mem_chain_for_Store(ir_node *store, ir_node *curr) {
 	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;
+	}
+}
+
 /**
  * optimize a Store
  *
  * @param store  the Store node
  */
 static unsigned optimize_store(ir_node *store) {
-	ir_node *ptr, *mem;
+	ir_node   *ptr;
+	ir_node   *mem;
+	ir_entity *entity;
 
 	if (get_Store_volatility(store) == volatility_is_volatile)
 		return 0;
 
-	ptr = get_Store_ptr(store);
+	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) {
+			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. */
@@ -2145,8 +2192,8 @@ void optimize_load_store(ir_graph *irg) {
 	assure_postdoms(irg);
 
 	if (get_opt_alias_analysis()) {
-		assure_irg_address_taken_computed(irg);
-		assure_irp_globals_address_taken_computed();
+		assure_irg_entity_usage_computed(irg);
+		assure_irp_globals_entity_usage_computed();
 	}
 
 	obstack_init(&env.obst);
@@ -2166,6 +2213,7 @@ void optimize_load_store(ir_graph *irg) {
 	/* 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) {