From 68bcb7db193e4bc81430063148253d30a791023e Mon Sep 17 00:00:00 2001
From: Dimitry Andric <dim@FreeBSD.org>
Date: Sun, 11 May 2014 18:24:26 +0000
Subject: Vendor import of llvm RELEASE_34/dot1-final tag r208032 (effectively,
 3.4.1 release):
 https://llvm.org/svn/llvm-project/llvm/tags/RELEASE_34/dot1-final@208032

---
 lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

(limited to 'lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp')

diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
index 054e3dd840b5..c1893c9231f0 100644
--- a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
@@ -219,8 +219,11 @@ void ScheduleDAGSDNodes::ClusterNeighboringLoads(SDNode *Node) {
   DenseMap<long long, SDNode*> O2SMap;  // Map from offset to SDNode.
   bool Cluster = false;
   SDNode *Base = Node;
+  // This algorithm requires a reasonably low use count before finding a match
+  // to avoid uselessly blowing up compile time in large blocks.
+  unsigned UseCount = 0;
   for (SDNode::use_iterator I = Chain->use_begin(), E = Chain->use_end();
-       I != E; ++I) {
+       I != E && UseCount < 100; ++I, ++UseCount) {
     SDNode *User = *I;
     if (User == Node || !Visited.insert(User))
       continue;
@@ -237,6 +240,8 @@ void ScheduleDAGSDNodes::ClusterNeighboringLoads(SDNode *Node) {
     if (Offset2 < Offset1)
       Base = User;
     Cluster = true;
+    // Reset UseCount to allow more matches.
+    UseCount = 0;
   }
 
   if (!Cluster)
-- 
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