1 files changed, 153 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Target/SystemZ/SystemZMachineScheduler.cpp b/contrib/llvm/lib/Target/SystemZ/SystemZMachineScheduler.cpp
new file mode 100644
index 0000000..ab6020f
--- /dev/null
+++ b/contrib/llvm/lib/Target/SystemZ/SystemZMachineScheduler.cpp
@@ -0,0 +1,153 @@
+//-- SystemZMachineScheduler.cpp - SystemZ Scheduler Interface -*- C++ -*---==//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// -------------------------- Post RA scheduling ---------------------------- //
+// SystemZPostRASchedStrategy is a scheduling strategy which is plugged into
+// the MachineScheduler. It has a sorted Available set of SUs and a pickNode()
+// implementation that looks to optimize decoder grouping and balance the
+// usage of processor resources.
+//===----------------------------------------------------------------------===//
+
+#include "SystemZMachineScheduler.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "misched"
+
+#ifndef NDEBUG
+// Print the set of SUs
+void SystemZPostRASchedStrategy::SUSet::
+dump(SystemZHazardRecognizer &HazardRec) {
+  dbgs() << "{";
+  for (auto &SU : *this) {
+    HazardRec.dumpSU(SU, dbgs());
+    if (SU != *rbegin())
+      dbgs() << ",  ";
+  }
+  dbgs() << "}\n";
+}
+#endif
+
+SystemZPostRASchedStrategy::
+SystemZPostRASchedStrategy(const MachineSchedContext *C)
+  : DAG(nullptr), HazardRec(C) {}
+
+void SystemZPostRASchedStrategy::initialize(ScheduleDAGMI *dag) {
+  DAG = dag;
+  HazardRec.setDAG(dag);
+  HazardRec.Reset();
+}
+
+// Pick the next node to schedule.
+SUnit *SystemZPostRASchedStrategy::pickNode(bool &IsTopNode) {
+  // Only scheduling top-down.
+  IsTopNode = true;
+
+  if (Available.empty())
+    return nullptr;
+
+  // If only one choice, return it.
+  if (Available.size() == 1) {
+    DEBUG (dbgs() << "+++ Only one: ";
+           HazardRec.dumpSU(*Available.begin(), dbgs()); dbgs() << "\n";);
+    return *Available.begin();
+  }
+
+  // All nodes that are possible to schedule are stored by in the
+  // Available set.
+  DEBUG(dbgs() << "+++ Available: "; Available.dump(HazardRec););
+
+  Candidate Best;
+  for (auto *SU : Available) {
+
+    // SU is the next candidate to be compared against current Best.
+    Candidate c(SU, HazardRec);
+
+    // Remeber which SU is the best candidate.
+    if (Best.SU == nullptr || c < Best) {
+      Best = c;
+      DEBUG(dbgs() << "+++ Best sofar: ";
+            HazardRec.dumpSU(Best.SU, dbgs());
+            if (Best.GroupingCost != 0)
+              dbgs() << "\tGrouping cost:" << Best.GroupingCost;
+            if (Best.ResourcesCost != 0)
+              dbgs() << " Resource cost:" << Best.ResourcesCost;
+            dbgs() << " Height:" << Best.SU->getHeight();
+            dbgs() << "\n";);
+    }
+
+    // Once we know we have seen all SUs that affect grouping or use unbuffered
+    // resources, we can stop iterating if Best looks good.
+    if (!SU->isScheduleHigh && Best.noCost())
+      break;
+  }
+
+  assert (Best.SU != nullptr);
+  return Best.SU;
+}
+
+SystemZPostRASchedStrategy::Candidate::
+Candidate(SUnit *SU_, SystemZHazardRecognizer &HazardRec) : Candidate() {
+  SU = SU_;
+
+  // Check the grouping cost. For a node that must begin / end a
+  // group, it is positive if it would do so prematurely, or negative
+  // if it would fit naturally into the schedule.
+  GroupingCost = HazardRec.groupingCost(SU);
+
+    // Check the resources cost for this SU.
+  ResourcesCost = HazardRec.resourcesCost(SU);
+}
+
+bool SystemZPostRASchedStrategy::Candidate::
+operator<(const Candidate &other) {
+
+  // Check decoder grouping.
+  if (GroupingCost < other.GroupingCost)
+    return true;
+  if (GroupingCost > other.GroupingCost)
+    return false;
+
+  // Compare the use of resources.
+  if (ResourcesCost < other.ResourcesCost)
+    return true;
+  if (ResourcesCost > other.ResourcesCost)
+    return false;
+
+  // Higher SU is otherwise generally better.
+  if (SU->getHeight() > other.SU->getHeight())
+    return true;
+  if (SU->getHeight() < other.SU->getHeight())
+    return false;
+
+  // If all same, fall back to original order.
+  if (SU->NodeNum < other.SU->NodeNum)
+    return true;
+
+  return false;
+}
+
+void SystemZPostRASchedStrategy::schedNode(SUnit *SU, bool IsTopNode) {
+  DEBUG(dbgs() << "+++ Scheduling SU(" << SU->NodeNum << ")\n";);
+
+  // Remove SU from Available set and update HazardRec.
+  Available.erase(SU);
+  HazardRec.EmitInstruction(SU);
+}
+
+void SystemZPostRASchedStrategy::releaseTopNode(SUnit *SU) {
+  // Set isScheduleHigh flag on all SUs that we want to consider first in
+  // pickNode().
+  const MCSchedClassDesc *SC = DAG->getSchedClass(SU);
+  bool AffectsGrouping = (SC->isValid() && (SC->BeginGroup || SC->EndGroup));
+  SU->isScheduleHigh = (AffectsGrouping || SU->isUnbuffered);
+
+  // Put all released SUs in the Available set.
+  Available.insert(SU);
+}