X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;ds=sidebyside;f=ir%2Fopt%2Fldstopt.c;h=91347a7bea9076376bfdfabd3af816ae9dc332fa;hb=44faeb9742640d3498eb4482f98eb1255607c4d6;hp=6ecabaae64760be85a57eeefde67a62edda6e09d;hpb=df8a7c32fa1de6a6c64b69f01e2748efb7ce1c11;p=libfirm

diff --git a/ir/opt/ldstopt.c b/ir/opt/ldstopt.c
index 6ecabaae6..91347a7be 100644
--- a/ir/opt/ldstopt.c
+++ b/ir/opt/ldstopt.c
@@ -28,7 +28,6 @@
 #endif
 
 #include <string.h>
-#include <stdbool.h>
 
 #include "iroptimize.h"
 #include "irnode_t.h"
@@ -387,11 +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 {
@@ -400,6 +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)) {
@@ -420,10 +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");
@@ -443,7 +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;
 		}
@@ -501,7 +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 {
@@ -539,7 +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);
 
@@ -773,41 +775,77 @@ static unsigned is_Call_pure(ir_node *call) {
 	return (prop & (mtp_property_const|mtp_property_pure)) != 0;
 }  /* is_Call_pure */
 
-static ir_node *get_base_ptr(ir_node *ptr)
+static ir_node *get_base_and_offset(ir_node *ptr, long *pOffset)
 {
-	while (is_Add(ptr) && is_Const(get_Add_right(ptr))) {
-		ptr = get_Add_left(ptr);
-	}
-
-	return ptr;
-}
+	ir_mode *mode  = get_irn_mode(ptr);
+	long    offset = 0;
 
-static long get_base_offset(ir_node *ptr)
-{
 	/* TODO: long might not be enough, we should probably use some tarval thingy... */
-	long offset = 0;
-	while (is_Add(ptr)) {
-		ir_node *right = get_Add_right(ptr);
-		if (!is_Const(right))
+	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;
-		offset += get_tarval_long(get_Const_tarval(right));
-		ptr = get_Add_left(ptr);
 	}
 
-	return offset;
+	*pOffset = offset;
+	return ptr;
 }
 
-static int try_load_store(ir_node *load,
+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);
-	ir_node *store_base_ptr = get_base_ptr(store_ptr);
+	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     store_offset   = get_base_offset(store_ptr);
 	long     load_mode_len;
 	long     store_mode_len;
 	long     delta;
@@ -816,25 +854,26 @@ static int try_load_store(ir_node *load,
 	if (load_base_ptr != store_base_ptr)
 		return 0;
 
-	load_mode     = get_Load_mode(load);
-	load_mode_len = get_mode_size_bytes(load_mode);
+	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;
-	if (delta < 0 || delta >= store_mode_len)
+	delta          = load_offset - store_offset;
+	if (delta < 0 || delta + load_mode_len > store_mode_len)
 		return 0;
 
-	if (store_mode_len - delta > load_mode_len)
+	if (get_mode_arithmetic(store_mode) != irma_twos_complement ||
+	    get_mode_arithmetic(load_mode)  != irma_twos_complement)
 		return 0;
 
 	store_value = get_Store_value(store);
-	DBG_OPT_RAW(load, store_value);
 
 	/* produce a shift to adjust offset delta */
 	if (delta > 0) {
-		ir_node *cnst = new_r_Const_long(current_ir_graph,
-				get_irg_start_block(current_ir_graph), mode_Iu, delta * 8);
+		ir_node *cnst;
+
+		/* FIXME: only true for little endian */
+		cnst        = new_Const_long(mode_Iu, delta * 8);
 		store_value = new_r_Shr(current_ir_graph, get_nodes_block(load),
 		                        store_value, cnst, store_mode);
 	}
@@ -845,6 +884,8 @@ static int try_load_store(ir_node *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));
@@ -880,14 +921,12 @@ static int try_load_store(ir_node *load,
  * INC_MASTER() must be called before dive into
  */
 static unsigned follow_Mem_chain(ir_node *load, ir_node *curr) {
-	unsigned res = 0;
+	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);
-	ir_node *base_ptr  = get_base_ptr(ptr);
-	long     load_offset = get_base_offset(ptr);
+	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);
@@ -909,11 +948,12 @@ static unsigned follow_Mem_chain(ir_node *load, ir_node *curr) {
 				&& info->projs[pn_Load_X_except] == NULL)
 				|| get_nodes_MacroBlock(load) == get_nodes_MacroBlock(pred)))
 		{
-			int changes
-				= try_load_store(load, base_ptr, load_offset, pred);
-			if (changes != 0) {
+			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)) {
 			/*
@@ -1047,9 +1087,10 @@ ir_node *can_replace_load_by_const(const ir_node *load, ir_node *c) {
 static unsigned optimize_load(ir_node *load)
 {
 	ldst_info_t *info = get_irn_link(load);
-	ir_node *mem, *ptr, *value;
-	ir_entity *ent;
-	unsigned res = 0;
+	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)
@@ -1150,6 +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);
 							}
 						}
@@ -1186,8 +1228,8 @@ static unsigned optimize_load(ir_node *load)
 	}
 
 	/* 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_n_uses(ptr) <= 1 && get_irn_n_uses(get_base_ptr(ptr)) <= 1)
+	 * 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;
 
 	/*
@@ -1314,18 +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. */
@@ -2107,8 +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);
@@ -2128,6 +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) {