1//===-- PPCHazardRecognizers.h - PowerPC Hazard Recognizers -----*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file defines hazard recognizers for scheduling on PowerPC processors.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef PPCHAZRECS_H
15#define PPCHAZRECS_H
16
17#include "llvm/CodeGen/ScheduleHazardRecognizer.h"
18#include "llvm/CodeGen/SelectionDAGNodes.h"
19#include "PPCInstrInfo.h"
20
21namespace llvm {
22
23/// PPCHazardRecognizer970 - This class defines a finite state automata that
24/// models the dispatch logic on the PowerPC 970 (aka G5) processor.  This
25/// promotes good dispatch group formation and implements noop insertion to
26/// avoid structural hazards that cause significant performance penalties (e.g.
27/// setting the CTR register then branching through it within a dispatch group),
28/// or storing then loading from the same address within a dispatch group.
29class PPCHazardRecognizer970 : public ScheduleHazardRecognizer {
30  const TargetInstrInfo &TII;
31
32  unsigned NumIssued;  // Number of insts issued, including advanced cycles.
33
34  // Various things that can cause a structural hazard.
35
36  // HasCTRSet - If the CTR register is set in this group, disallow BCTRL.
37  bool HasCTRSet;
38
39  // StoredPtr - Keep track of the address of any store.  If we see a load from
40  // the same address (or one that aliases it), disallow the store.  We can have
41  // up to four stores in one dispatch group, hence we track up to 4.
42  //
43  // This is null if we haven't seen a store yet.  We keep track of both
44  // operands of the store here, since we support [r+r] and [r+i] addressing.
45  SDValue StorePtr1[4], StorePtr2[4];
46  unsigned  StoreSize[4];
47  unsigned NumStores;
48
49public:
50  PPCHazardRecognizer970(const TargetInstrInfo &TII);
51  virtual HazardType getHazardType(SUnit *SU, int Stalls);
52  virtual void EmitInstruction(SUnit *SU);
53  virtual void AdvanceCycle();
54
55private:
56  /// EndDispatchGroup - Called when we are finishing a new dispatch group.
57  ///
58  void EndDispatchGroup();
59
60  /// GetInstrType - Classify the specified powerpc opcode according to its
61  /// pipeline.
62  PPCII::PPC970_Unit GetInstrType(unsigned Opcode,
63                                  bool &isFirst, bool &isSingle,bool &isCracked,
64                                  bool &isLoad, bool &isStore);
65
66  bool isLoadOfStoredAddress(unsigned LoadSize,
67                             SDValue Ptr1, SDValue Ptr2) const;
68};
69
70} // end namespace llvm
71
72#endif
73
74