misched: ILP scheduler for experimental heuristics.

[oota-llvm.git] / lib / CodeGen / MachineSink.cpp

diff --git a/lib/CodeGen/MachineSink.cpp b/lib/CodeGen/MachineSink.cpp
index f43f810f857deb77ae7704667d3eba735e5df0bd..bc383cba455c79e09175eade07e3ff0ae3cdec73 100644 (file)
--- a/lib/CodeGen/MachineSink.cpp
+++ b/lib/CodeGen/MachineSink.cpp
@@ -99,9 +99,20 @@ namespace {
     bool PerformTrivialForwardCoalescing(MachineInstr *MI,
                                          MachineBasicBlock *MBB);
   };
+
+  // SuccessorSorter - Sort Successors according to their loop depth. 
+  struct SuccessorSorter {
+    SuccessorSorter(MachineLoopInfo *LoopInfo) : LI(LoopInfo) {}
+    bool operator()(const MachineBasicBlock *LHS,
+                    const MachineBasicBlock *RHS) const {
+      return LI->getLoopDepth(LHS) < LI->getLoopDepth(RHS);
+    }
+    MachineLoopInfo *LI;
+  };
 } // end anonymous namespace
 
 char MachineSinking::ID = 0;
+char &llvm::MachineSinkingID = MachineSinking::ID;
 INITIALIZE_PASS_BEGIN(MachineSinking, "machine-sink",
                 "Machine code sinking", false, false)
 INITIALIZE_PASS_DEPENDENCY(MachineDominatorTree)
@@ -110,8 +121,6 @@ INITIALIZE_AG_DEPENDENCY(AliasAnalysis)
 INITIALIZE_PASS_END(MachineSinking, "machine-sink",
                 "Machine code sinking", false, false)
 
-FunctionPass *llvm::createMachineSinkingPass() { return new MachineSinking(); }
-
 bool MachineSinking::PerformTrivialForwardCoalescing(MachineInstr *MI,
                                                      MachineBasicBlock *MBB) {
   if (!MI->isCopy())
@@ -527,8 +536,11 @@ MachineBasicBlock *MachineSinking::FindSuccToSinkTo(MachineInstr *MI,
 
       // Otherwise, we should look at all the successors and decide which one
       // we should sink to.
-      for (MachineBasicBlock::succ_iterator SI = MBB->succ_begin(),
-           E = MBB->succ_end(); SI != E; ++SI) {
+      // We give successors with smaller loop depth higher priority.
+      SmallVector<MachineBasicBlock*, 4> Succs(MBB->succ_begin(), MBB->succ_end());
+      std::stable_sort(Succs.begin(), Succs.end(), SuccessorSorter(LI));
+      for (SmallVector<MachineBasicBlock*, 4>::iterator SI = Succs.begin(),
+           E = Succs.end(); SI != E; ++SI) {
         MachineBasicBlock *SuccBlock = *SI;
         bool LocalUse = false;
         if (AllUsesDominatedByBlock(Reg, SuccBlock, MBB,