From b1ce7b132497e0c05d2201f75d43d0f803ba7f88 Mon Sep 17 00:00:00 2001
From: Jakob Stoklund Olesen <stoklund@2pi.dk>
Date: Sun, 21 Feb 2010 18:51:48 +0000
Subject: [PATCH] Enable assertion to detect cyclic valno references.

This changes the stack overflow in PR6363 to an assertion failure.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96744 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/SimpleRegisterCoalescing.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/CodeGen/SimpleRegisterCoalescing.cpp b/lib/CodeGen/SimpleRegisterCoalescing.cpp
index e7b0cff53b3..dcbbb1a0045 100644
--- a/lib/CodeGen/SimpleRegisterCoalescing.cpp
+++ b/lib/CodeGen/SimpleRegisterCoalescing.cpp
@@ -1864,7 +1864,7 @@ static unsigned ComputeUltimateVN(VNInfo *VNI,
   // If the VN has already been computed, just return it.
   if (ThisValNoAssignments[VN] >= 0)
     return ThisValNoAssignments[VN];
-//  assert(ThisValNoAssignments[VN] != -2 && "Cyclic case?");
+  assert(ThisValNoAssignments[VN] != -2 && "Cyclic value numbers");
 
   // If this val is not a copy from the other val, then it must be a new value
   // number in the destination.