misched interface: Expose the MachineScheduler pass.

Allow targets to provide their own schedulers (subclass of
ScheduleDAGInstrs) to the misched pass. Select schedulers using
-misched=...

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152278 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/CodeGen/MachineScheduler.h

@@ -0,0 +1,86 @@
+//==- MachineScheduler.h - MachineInstr Scheduling Pass ----------*- C++ -*-==//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file provides a MachineSchedRegistry for registering alternative machine
+// schedulers. A Target may provide an alternative scheduler implementation by
+// implementing the following boilerplate:
+//
+// static ScheduleDAGInstrs *createCustomMachineSched(MachineSchedContext *C) {
+//  return new CustomMachineScheduler(C);
+// }
+// static MachineSchedRegistry
+// SchedDefaultRegistry("custom", "Run my target's custom scheduler",
+//                      createCustomMachineSched);
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef MACHINESCHEDULER_H
+#define MACHINESCHEDULER_H
+
+#include "llvm/CodeGen/MachinePassRegistry.h"
+
+namespace llvm {
+
+class AliasAnalysis;
+class LiveIntervals;
+class MachineDominatorTree;
+class MachineLoopInfo;
+class ScheduleDAGInstrs;
+
+/// MachineSchedContext provides enough context from the MachineScheduler pass
+/// for the target to instantiate a scheduler.
+struct MachineSchedContext {
+  MachineFunction *MF;
+  const MachineLoopInfo *MLI;
+  const MachineDominatorTree *MDT;
+  AliasAnalysis *AA;
+  LiveIntervals *LIS;
+
+  MachineSchedContext(): MF(0), MLI(0), MDT(0), AA(0), LIS(0) {}
+};
+
+/// MachineSchedRegistry provides a selection of available machine instruction
+/// schedulers.
+class MachineSchedRegistry : public MachinePassRegistryNode {
+public:
+  typedef ScheduleDAGInstrs *(*ScheduleDAGCtor)(MachineSchedContext *);
+
+  // RegisterPassParser requires a (misnamed) FunctionPassCtor type.
+  typedef ScheduleDAGCtor FunctionPassCtor;
+
+  static MachinePassRegistry Registry;
+
+  MachineSchedRegistry(const char *N, const char *D, ScheduleDAGCtor C)
+    : MachinePassRegistryNode(N, D, (MachinePassCtor)C) {
+    Registry.Add(this);
+  }
+  ~MachineSchedRegistry() { Registry.Remove(this); }
+
+  // Accessors.
+  //
+  MachineSchedRegistry *getNext() const {
+    return (MachineSchedRegistry *)MachinePassRegistryNode::getNext();
+  }
+  static MachineSchedRegistry *getList() {
+    return (MachineSchedRegistry *)Registry.getList();
+  }
+  static ScheduleDAGCtor getDefault() {
+    return (ScheduleDAGCtor)Registry.getDefault();
+  }
+  static void setDefault(ScheduleDAGCtor C) {
+    Registry.setDefault((MachinePassCtor)C);
+  }
+  static void setListener(MachinePassRegistryListener *L) {
+    Registry.setListener(L);
+  }
+};
+
+} // namespace llvm
+
+#endif