From 6da915ac865084e35452b3b6cb71cd0d721e4c33 Mon Sep 17 00:00:00 2001
From: Lang Hames <lhames@gmail.com>
Date: Sun, 15 Nov 2009 04:39:51 +0000
Subject: [PATCH] Added an assert to the PBQP allocator to catch infinite cost
 solutions which might otherwise lead to miscompilations.

llvm-svn: 88829
---
 llvm/lib/CodeGen/RegAllocPBQP.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/llvm/lib/CodeGen/RegAllocPBQP.cpp b/llvm/lib/CodeGen/RegAllocPBQP.cpp
index 5757e4755469..c677d341bef9 100644
--- a/llvm/lib/CodeGen/RegAllocPBQP.cpp
+++ b/llvm/lib/CodeGen/RegAllocPBQP.cpp
@@ -693,6 +693,11 @@ void PBQPRegAlloc::addStackInterval(const LiveInterval *spilled,
 }
 
 bool PBQPRegAlloc::mapPBQPToRegAlloc(const PBQP::Solution &solution) {
+
+  // Assert that this is a valid solution to the regalloc problem.
+  assert(solution.getCost() != std::numeric_limits<PBQP::PBQPNum>::infinity() &&
+         "Invalid (infinite cost) solution for PBQP problem.");
+
   // Set to true if we have any spills
   bool anotherRoundNeeded = false;