From: Jonas Fietz <fietz@ipd.info.uni-karlsruhe.de>
Date: Thu, 20 May 2010 15:02:27 +0000 (+0000)
Subject: Fix a bug in comparison evaluation
X-Git-Url: http://nsz.repo.hu/git/?a=commitdiff_plain;h=c7423b9349a4a6652ea4035f72363a947ac59a3a;hp=ea7d4bf45d9be3e4bd804cdd20652b85ff6abaf2;p=libfirm

Fix a bug in comparison evaluation

VRP/jumpthreading: In the case of a calculated Lg-eval, the optimization sometimes assumed a false
result.

[r27568]
---

diff --git a/ir/opt/jumpthreading.c b/ir/opt/jumpthreading.c
index 945ca526b..3f9e42e6d 100644
--- a/ir/opt/jumpthreading.c
+++ b/ir/opt/jumpthreading.c
@@ -385,13 +385,16 @@ static int eval_cmp_tv(pn_Cmp pnc, tarval *tv_left, tarval *tv_right)
 static int eval_cmp_vrp(pn_Cmp pnc, ir_node *left, ir_node *right)
 {
 	pn_Cmp cmp_result = vrp_cmp(left, right);
-
 	/* does the compare evaluate to true? */
-	if (cmp_result == pn_Cmp_False)
+	if (cmp_result == pn_Cmp_False) {
 		return -1;
-	if ((cmp_result & pnc) != cmp_result)
+	}
+	if ((cmp_result & pnc) != cmp_result) {
+		if ((cmp_result & pnc) != 0) {
+			return -1;
+		}
 		return 0;
-
+	}
 	return 1;
 }
 /**