From: Xinliang David Li <davidxl@google.com>
Date: Sat, 2 Mar 2013 18:42:26 +0000 (+0000)
Subject: PR/56490
X-Git-Tag: releases/gcc-4.8.0~234
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=4dc1d68cf2c8bff8d984c26413d81c0041d6e9e8;p=thirdparty%2Fgcc.git

PR/56490

From-SVN: r196406
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index fa0bb7655d09..32f6e4b6f0fe 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2013-03-01  Xinliang David Li  <davidxl@google.com>
+
+	* tree-ssa-uninit.c (compute_control_dep_chain): Limit post-dom
+	walk length.
+
 2013-03-01  Jakub Jelinek  <jakub@redhat.com>
 
 	PR middle-end/56461
diff --git a/gcc/tree-ssa-uninit.c b/gcc/tree-ssa-uninit.c
index a91ee379d696..e8f3ff7e7302 100644
--- a/gcc/tree-ssa-uninit.c
+++ b/gcc/tree-ssa-uninit.c
@@ -229,6 +229,7 @@ find_control_equiv_block (basic_block bb)
 
 #define MAX_NUM_CHAINS 8
 #define MAX_CHAIN_LEN 5
+#define MAX_POSTDOM_CHECK 8
 
 /* Computes the control dependence chains (paths of edges)
    for DEP_BB up to the dominating basic block BB (the head node of a
@@ -269,6 +270,7 @@ compute_control_dep_chain (basic_block bb, basic_block dep_bb,
   FOR_EACH_EDGE (e, ei, bb->succs)
     {
       basic_block cd_bb;
+      int post_dom_check = 0;
       if (e->flags & (EDGE_FAKE | EDGE_ABNORMAL))
         continue;
 
@@ -298,7 +300,8 @@ compute_control_dep_chain (basic_block bb, basic_block dep_bb,
             }
 
           cd_bb = find_pdom (cd_bb);
-          if (cd_bb == EXIT_BLOCK_PTR)
+          post_dom_check++;
+          if (cd_bb == EXIT_BLOCK_PTR || post_dom_check > MAX_POSTDOM_CHECK)
             break;
         }
       cur_cd_chain->pop ();