From fff0dfd810d462a3450e6fa1fffec2ecffeff3d2 Mon Sep 17 00:00:00 2001
From: Jakob Stoklund Olesen <stoklund@2pi.dk>
Date: Wed, 1 Feb 2012 22:19:26 +0000
Subject: [PATCH] Fix a bug in the TopoOrderRC comparison function.

The final tie breaker comparison also needs to return +/-1, or 0.
This is not a less() function.

This could cause otherwise identical super-classes to be ordered
unstably, depending on what the system qsort routine does with a bad
compare function.

llvm-svn: 149549
---
 llvm/utils/TableGen/CodeGenRegisters.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/llvm/utils/TableGen/CodeGenRegisters.cpp b/llvm/utils/TableGen/CodeGenRegisters.cpp
index 7c6661742aac..1d06f3e52876 100644
--- a/llvm/utils/TableGen/CodeGenRegisters.cpp
+++ b/llvm/utils/TableGen/CodeGenRegisters.cpp
@@ -503,7 +503,7 @@ static int TopoOrderRC(const void *PA, const void *PB) {
     return 1;
 
   // Finally order by name as a tie breaker.
-  return A->getName() < B->getName();
+  return StringRef(A->getName()).compare(B->getName());
 }
 
 std::string CodeGenRegisterClass::getQualifiedName() const {