From 501dc4224586d3cee61101ed6cd0ccc8ba74c43c Mon Sep 17 00:00:00 2001
From: Jakob Stoklund Olesen <stoklund@2pi.dk>
Date: Tue, 26 Oct 2010 22:36:07 +0000
Subject: [PATCH] Verify that live intervals are connected. If there are
 multiple connected components, each should get its own virtual register.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117407 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/MachineVerifier.cpp | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/lib/CodeGen/MachineVerifier.cpp b/lib/CodeGen/MachineVerifier.cpp
index d6d7dd45cc2..b5211ee65b3 100644
--- a/lib/CodeGen/MachineVerifier.cpp
+++ b/lib/CodeGen/MachineVerifier.cpp
@@ -167,7 +167,7 @@ namespace {
 
     // Analysis information if available
     LiveVariables *LiveVars;
-    const LiveIntervals *LiveInts;
+    LiveIntervals *LiveInts;
     SlotIndexes *Indexes;
 
     void visitMachineFunctionBefore();
@@ -1067,6 +1067,14 @@ void MachineVerifier::verifyLiveIntervals() {
         ++MFI;
       }
     }
+
+    // Check the LI only has one connected component.
+    ConnectedVNInfoEqClasses ConEQ(*LiveInts);
+    unsigned NumComp = ConEQ.Classify(&LI);
+    if (NumComp > 1) {
+      report("Multiple connected components in live interval", MF);
+      *OS << NumComp << " components in " << LI << '\n';
+    }
   }
 }