1//===---- ScheduleDAGSDNodes.h - SDNode Scheduling --------------*- 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 implements the ScheduleDAGSDNodes class, which implements
11// scheduling for an SDNode-based dependency graph.
12//
13//===----------------------------------------------------------------------===//
14
15#ifndef SCHEDULEDAGSDNODES_H
16#define SCHEDULEDAGSDNODES_H
17
18#include "llvm/CodeGen/ScheduleDAG.h"
19#include "llvm/CodeGen/SelectionDAG.h"
20
21namespace llvm {
22 /// ScheduleDAGSDNodes - A ScheduleDAG for scheduling SDNode-based DAGs.
23 ///
24 /// Edges between SUnits are initially based on edges in the SelectionDAG,
25 /// and additional edges can be added by the schedulers as heuristics.
26 /// SDNodes such as Constants, Registers, and a few others that are not
27 /// interesting to schedulers are not allocated SUnits.
28 ///
29 /// SDNodes with MVT::Flag operands are grouped along with the flagged
30 /// nodes into a single SUnit so that they are scheduled together.
31 ///
32 /// SDNode-based scheduling graphs do not use SDep::Anti or SDep::Output
33 /// edges. Physical register dependence information is not carried in
34 /// the DAG and must be handled explicitly by schedulers.
35 ///
36 class ScheduleDAGSDNodes : public ScheduleDAG {
37 public:
38 SelectionDAG *DAG; // DAG of the current basic block
39
40 explicit ScheduleDAGSDNodes(MachineFunction &mf);
41
42 virtual ~ScheduleDAGSDNodes() {}
43
44 /// Run - perform scheduling.
45 ///
46 void Run(SelectionDAG *dag, MachineBasicBlock *bb,
47 MachineBasicBlock::iterator insertPos);
48
49 /// isPassiveNode - Return true if the node is a non-scheduled leaf.
50 ///
51 static bool isPassiveNode(SDNode *Node) {
52 if (isa<ConstantSDNode>(Node)) return true;
53 if (isa<ConstantFPSDNode>(Node)) return true;
54 if (isa<RegisterSDNode>(Node)) return true;
55 if (isa<GlobalAddressSDNode>(Node)) return true;
56 if (isa<BasicBlockSDNode>(Node)) return true;
57 if (isa<FrameIndexSDNode>(Node)) return true;
58 if (isa<ConstantPoolSDNode>(Node)) return true;
59 if (isa<JumpTableSDNode>(Node)) return true;
60 if (isa<ExternalSymbolSDNode>(Node)) return true;
61 if (Node->getOpcode() == ISD::EntryToken) return true;
62 return false;
63 }
64
65 /// NewSUnit - Creates a new SUnit and return a ptr to it.
66 ///
67 SUnit *NewSUnit(SDNode *N) {
68#ifndef NDEBUG
69 const SUnit *Addr = 0;
70 if (!SUnits.empty())
71 Addr = &SUnits[0];
72#endif
73 SUnits.push_back(SUnit(N, (unsigned)SUnits.size()));
74 assert((Addr == 0 || Addr == &SUnits[0]) &&
75 "SUnits std::vector reallocated on the fly!");
76 SUnits.back().OrigNode = &SUnits.back();
77 return &SUnits.back();
78 }
79
80 /// Clone - Creates a clone of the specified SUnit. It does not copy the
81 /// predecessors / successors info nor the temporary scheduling states.
82 ///
83 SUnit *Clone(SUnit *N);
84
85 /// BuildSchedGraph - Build the SUnit graph from the selection dag that we
86 /// are input. This SUnit graph is similar to the SelectionDAG, but
87 /// excludes nodes that aren't interesting to scheduling, and represents
88 /// flagged together nodes with a single SUnit.
89 virtual void BuildSchedGraph(AliasAnalysis *AA);
90
91 /// ComputeLatency - Compute node latency.
92 ///
93 virtual void ComputeLatency(SUnit *SU);
94
95 virtual MachineBasicBlock *
96 EmitSchedule(DenseMap<MachineBasicBlock*, MachineBasicBlock*> *EM);
97
98 /// Schedule - Order nodes according to selected style, filling
99 /// in the Sequence member.
100 ///
101 virtual void Schedule() = 0;
102
103 virtual void dumpNode(const SUnit *SU) const;
104
105 virtual std::string getGraphNodeLabel(const SUnit *SU) const;
106
107 virtual void getCustomGraphFeatures(GraphWriter<ScheduleDAG*> &GW) const;
108
109 private:
110 /// BuildSchedUnits, AddSchedEdges - Helper functions for BuildSchedGraph.
111 void BuildSchedUnits();
112 void AddSchedEdges();
113 };
114}
115
116#endif