From: Cameron Zwarich <zwarich@apple.com>
Date: Wed, 29 Dec 2010 03:52:51 +0000 (+0000)
Subject: Add text explaining an assertion.
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=480b80a74648c9ea93b9a8986f9ca6a9de536abc;p=oota-llvm.git

Add text explaining an assertion.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122617 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/StrongPHIElimination.cpp b/lib/CodeGen/StrongPHIElimination.cpp
index 5713e6aed29..4749d8eca88 100644
--- a/lib/CodeGen/StrongPHIElimination.cpp
+++ b/lib/CodeGen/StrongPHIElimination.cpp
@@ -283,7 +283,9 @@ bool StrongPHIElimination::runOnMachineFunction(MachineFunction& MF) {
     LiveInterval& DestLI = LI->getInterval(DestReg);
     LiveInterval& NewLI = LI->getInterval(NewReg);
 
-    assert(DestLI.ranges.size() == 1);
+    assert(DestLI.ranges.size() == 1
+           && "PHI destination copy's live interval should be a single live "
+               "range from the beginning of the BB to the copy instruction.");
     LiveRange* DestLR = DestLI.begin();
     VNInfo* NewVNI = NewLI.getVNInfoAt(DestLR->start);
     if (!NewVNI) {