X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fopt%2Fopt_confirms.c;h=0908cb66a57283ddd261e146c562e0936e3595e1;hb=6be3a86348690a845e539da3954f6792465b4f05;hp=0e6ca9a58ca081c110ff7aa9984527549213e365;hpb=778f86e10809ed70dc9b509509c0d012dcfaf413;p=libfirm

diff --git a/ir/opt/opt_confirms.c b/ir/opt/opt_confirms.c
index 0e6ca9a58..0908cb66a 100644
--- a/ir/opt/opt_confirms.c
+++ b/ir/opt/opt_confirms.c
@@ -97,7 +97,7 @@ static tarval *compare_iv_dbg(const interval_t *l_iv, const interval_t *r_iv, pn
  * This is a often needed case, so we handle here Confirm
  * nodes too.
  */
-int value_not_zero(ir_node *n, ir_node **confirm) {
+int value_not_zero(const ir_node *n, ir_node_cnst_ptr *confirm) {
 #define RET_ON(x)  if (x) { *confirm = n; return 1; }; break
 
 	tarval *tv;
@@ -175,31 +175,37 @@ int value_not_zero(ir_node *n, ir_node **confirm) {
  * - A SymConst(entity) is NEVER a NULL pointer
  * - Confirms are evaluated
  */
-int value_not_null(ir_node *n, ir_node **confirm) {
-	ir_op *op;
+int value_not_null(const ir_node *n, ir_node_cnst_ptr *confirm) {
+	tarval *tv;
 
 	*confirm = NULL;
-	n  = skip_Cast(n);
+	n  = skip_Cast_const(n);
+
+	tv = value_of(n);
+	if (tarval_is_constant(tv) && ! tarval_is_null(tv))
+		return 1;
 
-	op = get_irn_op(n);
 	assert(mode_is_reference(get_irn_mode(n)));
 	if (get_opt_sel_based_null_check_elim()) {
 		/* skip all Sel nodes and Cast's */
-		while (op == op_Sel) {
+		while (is_Sel(n)) {
 			n = skip_Cast(get_Sel_ptr(n));
-			op = get_irn_op(n);
 		}
 	}
-	if (op == op_SymConst && get_SymConst_kind(n) == symconst_addr_ent)
+	if (is_Global(n)) {
+		/* global references are never NULL */
+		return 1;
+	} else if (n == get_irg_frame(current_ir_graph)) {
+		/* local references are never NULL */
 		return 1;
-	if (op == op_Const) {
-		if (!is_Const_null(n))
-			return 1;
 	} else {
+		/* check for more Confirms */
 		for (; is_Confirm(n); n = skip_Cast(get_Confirm_value(n))) {
-			if (get_Confirm_cmp(n) != pn_Cmp_Lg) {
+			if (get_Confirm_cmp(n) == pn_Cmp_Lg) {
 				ir_node *bound = get_Confirm_bound(n);
-				if (is_Const(bound) && is_Const_null(bound)) {
+				tarval  *tv    = value_of(bound);
+
+				if (tarval_is_null(tv)) {
 					*confirm = n;
 					return 1;
 				}
@@ -235,7 +241,7 @@ value_classify_sign classify_value_sign(ir_node *n) {
 		}
 		break;
 	}
-	if (get_irn_op(n) != op_Confirm)
+	if (!is_Confirm(n))
 		return value_classified_unknown;
 
 	tv  = value_of(get_Confirm_bound(n));
@@ -622,8 +628,9 @@ tarval *computed_value_Cmp_Confirm(ir_node *cmp, ir_node *left, ir_node *right,
 
 		pnc = get_inversed_pnc(pnc);
 	} else if (! is_Confirm(left)) {
-		/* no Confirm on either one side, finish */
-		return tarval_bad;
+		/* nothing more found */
+		tv = tarval_bad;
+		goto check_null_case;
 	}
 
 	/* ok, here at least left is a Confirm, right might be */
@@ -756,6 +763,24 @@ tarval *computed_value_Cmp_Confirm(ir_node *cmp, ir_node *left, ir_node *right,
 			get_interval(&l_iv, l_bound, l_pnc),
 			get_interval_from_tv(&r_iv, tv),
 			pnc);
+	} else {
+check_null_case:
+		/* check some other cases */
+		if ((pnc == pn_Cmp_Eq || pnc == pn_Cmp_Lg) &&
+			is_Const(right) && is_Const_null(right)) {
+			/* for == 0 or != 0 we have some special tools */
+			ir_mode       *mode = get_irn_mode(left);
+			const ir_node *dummy;
+			if (mode_is_reference(mode)) {
+				if (value_not_null(left, &dummy)) {
+					tv = pnc == pn_Cmp_Eq ? tarval_b_false : tarval_b_true;
+				}
+			} else {
+				if (value_not_zero(left, &dummy)) {
+					tv = pnc == pn_Cmp_Eq ? tarval_b_false : tarval_b_true;
+				}
+			}
+		}
 	}
 
 	if (tv != tarval_bad)