Rewrite the SDep class, and simplify some of the related code.

The Cost field is removed. It was only being used in a very limited way,
to indicate when the scheduler should attempt to protect a live register,
and it isn't really needed to do that. If we ever want the scheduler to
start inserting copies in non-prohibitive situations, we'll have to
rethink some things anyway.

A Latency field is added. Instead of giving each node a single
fixed latency, each edge can have its own latency. This will eventually
be used to model various micro-architecture properties more accurately.

The PointerIntPair class and an internal union are now used, which
reduce the overall size.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60806 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/ScheduleDAGEmit.cpp b/lib/CodeGen/ScheduleDAGEmit.cpp
index ce3283d..d10d670 100644
--- a/lib/CodeGen/ScheduleDAGEmit.cpp
+++ b/lib/CodeGen/ScheduleDAGEmit.cpp
@@ -40,31 +40,31 @@
                                   DenseMap<SUnit*, unsigned> &VRBaseMap) {
   for (SUnit::const_pred_iterator I = SU->Preds.begin(), E = SU->Preds.end();
        I != E; ++I) {
-    if (I->isCtrl) continue;  // ignore chain preds
-    if (I->Dep->CopyDstRC) {
+    if (I->isCtrl()) continue;  // ignore chain preds
+    if (I->getSUnit()->CopyDstRC) {
       // Copy to physical register.
-      DenseMap<SUnit*, unsigned>::iterator VRI = VRBaseMap.find(I->Dep);
+      DenseMap<SUnit*, unsigned>::iterator VRI = VRBaseMap.find(I->getSUnit());
       assert(VRI != VRBaseMap.end() && "Node emitted out of order - late");
       // Find the destination physical register.
       unsigned Reg = 0;
       for (SUnit::const_succ_iterator II = SU->Succs.begin(),
              EE = SU->Succs.end(); II != EE; ++II) {
-        if (I->Reg) {
-          Reg = I->Reg;
+        if (I->getReg()) {
+          Reg = I->getReg();
           break;
         }
       }
-      assert(I->Reg && "Unknown physical register!");
+      assert(I->getReg() && "Unknown physical register!");
       TII->copyRegToReg(*BB, BB->end(), Reg, VRI->second,
                         SU->CopyDstRC, SU->CopySrcRC);
     } else {
       // Copy from physical register.
-      assert(I->Reg && "Unknown physical register!");
+      assert(I->getReg() && "Unknown physical register!");
       unsigned VRBase = MRI.createVirtualRegister(SU->CopyDstRC);
       bool isNew = VRBaseMap.insert(std::make_pair(SU, VRBase)).second;
       isNew = isNew; // Silence compiler warning.
       assert(isNew && "Node emitted out of order - early");
-      TII->copyRegToReg(*BB, BB->end(), VRBase, I->Reg,
+      TII->copyRegToReg(*BB, BB->end(), VRBase, I->getReg(),
                         SU->CopyDstRC, SU->CopySrcRC);
     }
     break;