Iterating over sets of pointers in a heuristic was a bad idea. Switching

any command line paramater changed the register allocation produced by
PBQP.

Turns out variety is not the spice of life.

Fixed some comparators, added others. All good now.

llvm-svn: 108613

2 files changed, 12 insertions, 8 deletions

diff --git a/llvm/lib/CodeGen/PBQP/Heuristics/Briggs.h b/llvm/lib/CodeGen/PBQP/Heuristics/Briggs.h
index 4c1ce119ed0..18eaf7c0da9 100644
--- a/llvm/lib/CodeGen/PBQP/Heuristics/Briggs.h
+++ b/llvm/lib/CodeGen/PBQP/Heuristics/Briggs.h
@@ -52,9 +52,7 @@ namespace PBQP {
         bool operator()(Graph::NodeItr n1Itr, Graph::NodeItr n2Itr) const {
           if (s->getSolverDegree(n1Itr) > s->getSolverDegree(n2Itr))
             return true;
-          if (s->getSolverDegree(n1Itr) < s->getSolverDegree(n2Itr))
-            return false;
-          return (&*n1Itr < &*n2Itr);
+          return false;
         }
       private:
         HeuristicSolverImpl<Briggs> *s;
@@ -69,9 +67,7 @@ namespace PBQP {
                   cost2 = g->getNodeCosts(n2Itr)[0] / s->getSolverDegree(n2Itr);
           if (cost1 < cost2)
             return true;
-          if (cost1 > cost2)
-            return false;
-          return (&*n1Itr < &*n2Itr);
+          return false;
         }
 
       private:
diff --git a/llvm/lib/CodeGen/RegAllocPBQP.cpp b/llvm/lib/CodeGen/RegAllocPBQP.cpp
index 45104b48fe4..a7ea8e7c3ad 100644
--- a/llvm/lib/CodeGen/RegAllocPBQP.cpp
+++ b/llvm/lib/CodeGen/RegAllocPBQP.cpp
@@ -104,7 +104,15 @@ namespace {
     virtual bool runOnMachineFunction(MachineFunction &MF);
 
   private:
-    typedef std::map<const LiveInterval*, unsigned> LI2NodeMap;
+
+    class LIOrdering {
+    public:
+      bool operator()(const LiveInterval *li1, const LiveInterval *li2) const {
+        return li1->reg < li2->reg;
+      }
+    };
+
+    typedef std::map<const LiveInterval*, unsigned, LIOrdering> LI2NodeMap;
     typedef std::vector<const LiveInterval*> Node2LIMap;
     typedef std::vector<unsigned> AllowedSet;
     typedef std::vector<AllowedSet> AllowedSetMap;
@@ -112,7 +120,7 @@ namespace {
     typedef std::pair<unsigned, unsigned> RegPair;
     typedef std::map<RegPair, PBQP::PBQPNum> CoalesceMap;
 
-    typedef std::set<LiveInterval*> LiveIntervalSet;
+    typedef std::set<LiveInterval*, LIOrdering> LiveIntervalSet;
 
     typedef std::vector<PBQP::Graph::NodeItr> NodeVector;