X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fopt%2Fopt_confirms.c;h=28e0ef7d5588b7ad8c1738481bfd5d684fefb1f2;hb=c7dc950ac0cdd7d24acffb798b5867d0db5dd7c8;hp=a0f7ceb5318a246bfa9dd6f4b6d1e93d357bf204;hpb=3977737475ce98c71e45f363a053e47d5d1bb39d;p=libfirm

diff --git a/ir/opt/opt_confirms.c b/ir/opt/opt_confirms.c
index a0f7ceb53..28e0ef7d5 100644
--- a/ir/opt/opt_confirms.c
+++ b/ir/opt/opt_confirms.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 1995-2007 University of Karlsruhe.  All right reserved.
+ * Copyright (C) 1995-2008 University of Karlsruhe.  All right reserved.
  *
  * This file is part of libFirm.
  *
@@ -107,7 +107,15 @@ int value_not_zero(ir_node *n, ir_node **confirm) {
 	*confirm = NULL;
 
 	/* there might be several Confirms one after other that form an interval */
-	for (; is_Confirm(n); n = get_Confirm_value(n)) {
+	for (;;) {
+		if (is_Minus(n) || is_Abs(n)) {
+			/* we can safely skip Minus and Abs when checking for != 0 */
+			n = get_unop_op(n);
+			continue;
+		}
+		if (! is_Confirm(n))
+			break;
+
 		/*
 		 * Note: A Confirm is never after a Const. So,
 		 * we simply can check the bound for being a Const
@@ -143,6 +151,7 @@ int value_not_zero(ir_node *n, ir_node **confirm) {
 		default:
 			break;
 		}
+		n = get_Confirm_value(n);
 	}
 	tv = value_of(n);
 
@@ -181,14 +190,17 @@ int value_not_null(ir_node *n, ir_node **confirm) {
 			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;
-	if (op == op_Const) {
-		tarval *tv = get_Const_tarval(n);
-
-		if (tv != tarval_bad && !tarval_is_null(tv))
-			return 1;
+	} else if (n == get_irg_frame(current_ir_graph)) {
+		/* local references are never NULL */
+		return 1;
+	} else if (op == op_Const) {
+		/* explicit non-NULL addresses */
+		return !is_Const_null(n);
 	} else {
+		/* check for more Confirms */
 		for (; is_Confirm(n); n = skip_Cast(get_Confirm_value(n))) {
 			if (get_Confirm_cmp(n) != pn_Cmp_Lg) {
 				ir_node *bound = get_Confirm_bound(n);
@@ -211,7 +223,23 @@ value_classify_sign classify_value_sign(ir_node *n) {
 	tarval *tv, *c;
 	ir_mode *mode;
 	pn_Cmp cmp, ncmp;
+	int negate = 1;
 
+	for (;;) {
+		ir_opcode code = get_irn_opcode(n);
+
+		switch (code) {
+		case iro_Minus:
+			negate *= -1;
+			n = get_Minus_op(n);
+			continue;
+		case iro_Confirm:
+			break;
+		default:
+			return value_classified_unknown;
+		}
+		break;
+	}
 	if (get_irn_op(n) != op_Confirm)
 		return value_classified_unknown;
 
@@ -254,7 +282,7 @@ value_classify_sign classify_value_sign(ir_node *n) {
 			return value_classified_unknown;
 
 		/* yep, negative */
-		return value_classified_negative;
+		return value_classified_negative * negate;
 
 	case pn_Cmp_Ge:
 		/*
@@ -285,7 +313,7 @@ value_classify_sign classify_value_sign(ir_node *n) {
 		}
 
 		/* yep, positive */
-		return value_classified_positive;
+		return value_classified_positive * negate;
 
 	default:
 		return value_classified_unknown;
@@ -599,8 +627,9 @@ 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 */
@@ -733,6 +762,24 @@ 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);
+			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)