From: Arnaud A. de Grandmaison <arnaud.degrandmaison@arm.com>
Date: Tue, 21 Oct 2014 16:24:15 +0000 (+0000)
Subject: [PBQP] Fix coalescing benefits
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=d3648d0cbebfd7950329c793342ea8d12860e0fd;p=platform%2Fupstream%2Fllvm.git

[PBQP] Fix coalescing benefits

As coalescing registers is a benefit, the cost should be improved (i.e. made smaller) when coalescing is possible.

llvm-svn: 220302
---

diff --git a/llvm/lib/CodeGen/RegAllocPBQP.cpp b/llvm/lib/CodeGen/RegAllocPBQP.cpp
index 599fbad..5bd3374 100644
--- a/llvm/lib/CodeGen/RegAllocPBQP.cpp
+++ b/llvm/lib/CodeGen/RegAllocPBQP.cpp
@@ -350,7 +350,7 @@ public:
 
           if (PRegOpt < Allowed.size()) {
             PBQPRAGraph::RawVector NewCosts(G.getNodeCosts(NId));
-            NewCosts[PRegOpt + 1] += CBenefit;
+            NewCosts[PRegOpt + 1] -= CBenefit;
             G.setNodeCosts(NId, std::move(NewCosts));
           }
         } else {
@@ -395,7 +395,7 @@ private:
       for (unsigned J = 0; J != Allowed2.size(); ++J) {
         unsigned PReg2 = Allowed2[J];
         if (PReg1 == PReg2)
-          CostMat[I + 1][J + 1] += -Benefit;
+          CostMat[I + 1][J + 1] -= Benefit;
       }
     }
   }