[llvm] r187141 - RegAllocGreedy comment.

[Andrew Trick]

Author: atrick
Date: Thu Jul 25 13:35:22 2013
New Revision: 187141

URL: http://llvm.org/viewvc/llvm-project?rev=187141&view=rev
Log:
RegAllocGreedy comment.

Modified:
    llvm/trunk/lib/CodeGen/RegAllocGreedy.cpp

Modified: llvm/trunk/lib/CodeGen/RegAllocGreedy.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/RegAllocGreedy.cpp?rev=187141&r1=187140&r2=187141&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/RegAllocGreedy.cpp (original)
+++ llvm/trunk/lib/CodeGen/RegAllocGreedy.cpp Thu Jul 25 13:35:22 2013
@@ -434,7 +434,8 @@ void RAGreedy::enqueue(LiveInterval *LI)
     if (VRM->hasKnownPreference(Reg))
       Prio |= (1u << 30);
   }
-
+  // The virtual register number is a tie breaker for same-sized ranges.
+  // Give lower vreg numbers higher priority to assign them first.
   Queue.push(std::make_pair(Prio, ~Reg));
 }