[llvm-commits] [llvm] r136742 - /llvm/trunk/lib/CodeGen/RegAllocGreedy.cpp

[Jakob Stoklund Olesen]

Author: stoklund
Date: Tue Aug  2 18:04:08 2011
New Revision: 136742

URL: http://llvm.org/viewvc/llvm-project?rev=136742&view=rev
Log:
Use the precomputed def presence in RAGreedy::calcSpillCost.

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=136742&r1=136741&r2=136742&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/RegAllocGreedy.cpp (original)
+++ llvm/trunk/lib/CodeGen/RegAllocGreedy.cpp Tue Aug  2 18:04:08 2011
@@ -864,7 +864,6 @@
 /// SA around all use blocks instead of forming bundle regions.
 float RAGreedy::calcSpillCost() {
   float Cost = 0;
-  const LiveInterval &LI = SA->getParent();
   ArrayRef<SplitAnalysis::BlockInfo> UseBlocks = SA->getUseBlocks();
   for (unsigned i = 0; i != UseBlocks.size(); ++i) {
     const SplitAnalysis::BlockInfo &BI = UseBlocks[i];
@@ -873,16 +872,8 @@
     Cost += SpillPlacer->getBlockFrequency(Number);
 
     // Unless the value is redefined in the block.
-    if (BI.LiveIn && BI.LiveOut) {
-      SlotIndex Start, Stop;
-      tie(Start, Stop) = Indexes->getMBBRange(Number);
-      LiveInterval::const_iterator I = LI.find(Start);
-      assert(I != LI.end() && "Expected live-in value");
-      // Is there a different live-out value? If so, we need an extra spill
-      // instruction.
-      if (I->end < Stop)
-        Cost += SpillPlacer->getBlockFrequency(Number);
-    }
+    if (BI.LiveIn && BI.LiveOut && BI.FirstDef)
+      Cost += SpillPlacer->getBlockFrequency(Number);
   }
   return Cost;
 }