TargetSelectionDAGInfo.h revision 3574eca1b02600bac4e625297f4ecf745f4c4f32 
1//==-- llvm/Target/TargetSelectionDAGInfo.h - SelectionDAG Info --*- 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 declares the TargetSelectionDAGInfo class, which targets can
11// subclass to parameterize the SelectionDAG lowering and instruction
12// selection process.
13//
14//===----------------------------------------------------------------------===//
15
16#ifndef LLVM_TARGET_TARGETSELECTIONDAGINFO_H
17#define LLVM_TARGET_TARGETSELECTIONDAGINFO_H
18
19#include "llvm/CodeGen/SelectionDAGNodes.h"
20
21namespace llvm {
22
23class DataLayout;
24class TargetMachine;
25
26//===----------------------------------------------------------------------===//
27/// TargetSelectionDAGInfo - Targets can subclass this to parameterize the
28/// SelectionDAG lowering and instruction selection process.
29///
30class TargetSelectionDAGInfo {
31  TargetSelectionDAGInfo(const TargetSelectionDAGInfo &) LLVM_DELETED_FUNCTION;
32  void operator=(const TargetSelectionDAGInfo &) LLVM_DELETED_FUNCTION;
33
34  const DataLayout *TD;
35
36protected:
37  const DataLayout *getDataLayout() const { return TD; }
38
39public:
40  explicit TargetSelectionDAGInfo(const TargetMachine &TM);
41  virtual ~TargetSelectionDAGInfo();
42
43  /// EmitTargetCodeForMemcpy - Emit target-specific code that performs a
44  /// memcpy. This can be used by targets to provide code sequences for cases
45  /// that don't fit the target's parameters for simple loads/stores and can be
46  /// more efficient than using a library call. This function can return a null
47  /// SDValue if the target declines to use custom code and a different
48  /// lowering strategy should be used.
49  ///
50  /// If AlwaysInline is true, the size is constant and the target should not
51  /// emit any calls and is strongly encouraged to attempt to emit inline code
52  /// even if it is beyond the usual threshold because this intrinsic is being
53  /// expanded in a place where calls are not feasible (e.g. within the prologue
54  /// for another call). If the target chooses to decline an AlwaysInline
55  /// request here, legalize will resort to using simple loads and stores.
56  virtual SDValue
57  EmitTargetCodeForMemcpy(SelectionDAG &DAG, DebugLoc dl,
58                          SDValue Chain,
59                          SDValue Op1, SDValue Op2,
60                          SDValue Op3, unsigned Align, bool isVolatile,
61                          bool AlwaysInline,
62                          MachinePointerInfo DstPtrInfo,
63                          MachinePointerInfo SrcPtrInfo) const {
64    return SDValue();
65  }
66
67  /// EmitTargetCodeForMemmove - Emit target-specific code that performs a
68  /// memmove. This can be used by targets to provide code sequences for cases
69  /// that don't fit the target's parameters for simple loads/stores and can be
70  /// more efficient than using a library call. This function can return a null
71  /// SDValue if the target declines to use custom code and a different
72  /// lowering strategy should be used.
73  virtual SDValue
74  EmitTargetCodeForMemmove(SelectionDAG &DAG, DebugLoc dl,
75                           SDValue Chain,
76                           SDValue Op1, SDValue Op2,
77                           SDValue Op3, unsigned Align, bool isVolatile,
78                           MachinePointerInfo DstPtrInfo,
79                           MachinePointerInfo SrcPtrInfo) const {
80    return SDValue();
81  }
82
83  /// EmitTargetCodeForMemset - Emit target-specific code that performs a
84  /// memset. This can be used by targets to provide code sequences for cases
85  /// that don't fit the target's parameters for simple stores and can be more
86  /// efficient than using a library call. This function can return a null
87  /// SDValue if the target declines to use custom code and a different
88  /// lowering strategy should be used.
89  virtual SDValue
90  EmitTargetCodeForMemset(SelectionDAG &DAG, DebugLoc dl,
91                          SDValue Chain,
92                          SDValue Op1, SDValue Op2,
93                          SDValue Op3, unsigned Align, bool isVolatile,
94                          MachinePointerInfo DstPtrInfo) const {
95    return SDValue();
96  }
97};
98
99} // end llvm namespace
100
101#endif
102