X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fana%2Firconsconfirm.c;h=7d9b3fe2ee35b3142a5dd10177808f3f7b7819f1;hb=45ecc187cee7107c83c1f9618a1e1e586df73644;hp=c8f93461305a6de57516e238cdbd2508fc5cadcd;hpb=960d88fb7fd5805f957a66bdf7cbc034659b7a71;p=libfirm

diff --git a/ir/ana/irconsconfirm.c b/ir/ana/irconsconfirm.c
index c8f934613..7d9b3fe2e 100644
--- a/ir/ana/irconsconfirm.c
+++ b/ir/ana/irconsconfirm.c
@@ -46,9 +46,10 @@
  * Walker environment.
  */
 typedef struct _env_t {
-	unsigned num_confirms;  /**< number of inserted Confirm nodes */
-	unsigned num_consts;    /**< number of constants placed */
-	unsigned num_eq;        /**< number of equalities placed */
+	unsigned num_confirms;  /**< Number of inserted Confirm nodes. */
+	unsigned num_consts;    /**< Number of constants placed. */
+	unsigned num_eq;        /**< Number of equalities placed. */
+	unsigned num_non_null;  /**< Number of non-null Confirms. */
 } env_t;
 
 /** The debug handle. */
@@ -114,7 +115,7 @@ static void handle_case(ir_node *block, ir_node *irn, long nr, env_t *env) {
 
 			set_irn_n(succ, pos, c);
 			DBG_OPT_CONFIRM_C(irn, c);
-//			ir_printf("1 Replacing input %d of node %n with %n\n", pos, succ, c);
+			DB((dbg, LEVEL_2, "Replacing input %d of node %+F with %+F\n", pos, succ, c));
 
 			env->num_consts += 1;
 		}
@@ -153,7 +154,7 @@ static void handle_modeb(ir_node *block, ir_node *selector, pn_Cond pnc, env_t *
 			set_irn_n(user, pos, con);
 			DBG_OPT_CONFIRM_C(old, con);
 
-			DB((dbg, LEVEL_2, "Replacing input %d of node %n with %n\n", pos, user, con));
+			DB((dbg, LEVEL_2, "Replacing input %d of node %+F with %+F\n", pos, user, con));
 
 			env->num_consts += 1;
 		} else {
@@ -287,7 +288,7 @@ static void handle_if(ir_node *block, ir_node *cmp, pn_Cmp pnc, env_t *env) {
 				set_irn_n(user, pos, right);
 				DBG_OPT_CONFIRM(left, right);
 
-				DB((dbg, LEVEL_2, "Replacing input %d of node %n with %n\n", pos, user, right));
+				DB((dbg, LEVEL_2, "Replacing input %d of node %+F with %+F\n", pos, user, right));
 
 				env->num_eq += 1;
 			} else if (block_dominates(blk, cond_block)) {
@@ -347,7 +348,7 @@ static void handle_if(ir_node *block, ir_node *cmp, pn_Cmp pnc, env_t *env) {
 
 				pos = get_edge_src_pos(edge);
 				set_irn_n(succ, pos, c);
-				DB((dbg, LEVEL_2, "Replacing input %d of node %n with %n\n", pos, succ, c));
+				DB((dbg, LEVEL_2, "Replacing input %d of node %+F with %+F\n", pos, succ, c));
 
 				env->num_confirms += 1;
 			}
@@ -415,7 +416,32 @@ static void insert_Confirm_in_block(ir_node *block, void *env) {
 }  /* insert_Confirm_in_block */
 
 /**
- * The given will be dereferenced, add non-null confirms.
+ * Checks if a node is a non-null Confirm.
+ */
+static int is_non_null_Confirm(const ir_node *ptr) {
+	for (;;) {
+		if (! is_Confirm(ptr))
+			break;
+		if (get_Confirm_cmp(ptr) == pn_Cmp_Lg) {
+			ir_node *bound = get_Confirm_bound(ptr);
+
+			if (is_Const(bound) && is_Const_null(bound))
+				return 1;
+		}
+		ptr = get_Confirm_value(ptr);
+	}
+	/*
+	 * While a SymConst is not a Confirm, it is non-null
+	 * anyway. This helps to reduce the number of
+	 * constructed Confirms.
+	 */
+	if (is_SymConst_addr_ent(ptr))
+		return 1;
+	return 0;
+}  /* is_non_null_Confirm */
+
+/**
+ * The given pointer will be dereferenced, add non-null Confirms.
  *
  * @param ptr    a node representing an address
  * @param block  the block of the dereferencing instruction
@@ -431,14 +457,9 @@ static void insert_non_null(ir_node *ptr, ir_node *block, env_t *env) {
 		ir_node *blk;
 
 
-		if ((is_Load(succ) || is_Store(succ)) &&
-			get_nodes_block(succ) == block) {
-			/* Ignore Loads and Store in the same block for now,
-			   because we are not sure if they are dominated.
-			   This is not a bad restriction: if exception flow is
-			   present, they are in other blocks either. */
+		/* for now, we place a Confirm only in front of a Cmp */
+		if (! is_Cmp(succ))
 			continue;
-		}
 
 		pos = get_edge_src_pos(edge);
 		blk = get_effective_use_block(succ, pos);
@@ -457,31 +478,14 @@ static void insert_non_null(ir_node *ptr, ir_node *block, env_t *env) {
 			}
 
 			set_irn_n(succ, pos, c);
-			DB((dbg, LEVEL_2, "Replacing input %d of node %n with %n\n", pos, succ, c));
-
+			DB((dbg, LEVEL_2, "Replacing input %d of node %+F with %+F\n", pos, succ, c));
 
+			env->num_non_null += 1;
 			env->num_confirms += 1;
 		}
 	}
 }  /* insert_non_null */
 
-/**
- * Checks if a node is a non-null Confirm.
- */
-static int is_non_null_Confirm(const ir_node *ptr) {
-	for (;;) {
-		if (! is_Confirm(ptr))
-			return 0;
-		if (get_Confirm_cmp(ptr) == pn_Cmp_Lg) {
-			ir_node *bound = get_Confirm_bound(ptr);
-
-			if (is_Const(bound) && is_Const_null(bound))
-				return 1;
-		}
-		ptr = get_Confirm_value(ptr);
-	}
-}  /* is_non_null_Confirm */
-
 /**
  * Pre-walker: Called for every node to insert Confirm nodes
  */
@@ -533,6 +537,7 @@ void construct_confirms(ir_graph *irg) {
 	env.num_confirms = 0;
 	env.num_consts   = 0;
 	env.num_eq       = 0;
+	env.num_non_null = 0;
 
 	if (get_opt_global_null_ptr_elimination()) {
 		/* do global NULL test elimination */
@@ -553,6 +558,7 @@ void construct_confirms(ir_graph *irg) {
 	DB((dbg, LEVEL_1, "# Confirms inserted : %u\n", env.num_confirms));
 	DB((dbg, LEVEL_1, "# Const replacements: %u\n", env.num_consts));
 	DB((dbg, LEVEL_1, "# node equalities   : %u\n", env.num_eq));
+	DB((dbg, LEVEL_1, "# non-null Confirms : %u\n", env.num_non_null));
 
 	/* deactivate edges if they where off */
 	if (! edges_active)
@@ -571,7 +577,7 @@ static void rem_Confirm(ir_node *n, void *env) {
 			exchange(n, value);
 		else {
 			/*
-			 * Strange: a Confirm is it's own bound. This can happen
+			 * Strange: a Confirm is its own bound. This can happen
 			 * in dead blocks when Phi nodes are already removed.
 			 */
 			exchange(n, new_Bad());