1 //===---- ScheduleDAGSDNodes.h - SDNode Scheduling --------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the ScheduleDAGSDNodes class, which implements
11 // scheduling for an SDNode-based dependency graph.
13 //===----------------------------------------------------------------------===//
15 #ifndef SCHEDULEDAGSDNODES_H
16 #define SCHEDULEDAGSDNODES_H
18 #include "llvm/CodeGen/ScheduleDAG.h"
19 #include "llvm/CodeGen/SelectionDAG.h"
22 /// ScheduleDAGSDNodes - A ScheduleDAG for scheduling SDNode-based DAGs.
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.
29 /// SDNodes with MVT::Flag operands are grouped along with the flagged
30 /// nodes into a single SUnit so that they are scheduled together.
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.
36 class ScheduleDAGSDNodes : public ScheduleDAG {
38 SelectionDAG *DAG; // DAG of the current basic block
40 explicit ScheduleDAGSDNodes(MachineFunction &mf);
42 virtual ~ScheduleDAGSDNodes() {}
44 /// Run - perform scheduling.
46 void Run(SelectionDAG *dag, MachineBasicBlock *bb,
47 MachineBasicBlock::iterator insertPos);
49 /// isPassiveNode - Return true if the node is a non-scheduled leaf.
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 (isa<BlockAddressSDNode>(Node)) return true;
62 if (Node->getOpcode() == ISD::EntryToken ||
63 isa<MDNodeSDNode>(Node)) return true;
67 /// NewSUnit - Creates a new SUnit and return a ptr to it.
69 SUnit *NewSUnit(SDNode *N) {
71 const SUnit *Addr = 0;
75 SUnits.push_back(SUnit(N, (unsigned)SUnits.size()));
76 assert((Addr == 0 || Addr == &SUnits[0]) &&
77 "SUnits std::vector reallocated on the fly!");
78 SUnits.back().OrigNode = &SUnits.back();
79 return &SUnits.back();
82 /// Clone - Creates a clone of the specified SUnit. It does not copy the
83 /// predecessors / successors info nor the temporary scheduling states.
85 SUnit *Clone(SUnit *N);
87 /// BuildSchedGraph - Build the SUnit graph from the selection dag that we
88 /// are input. This SUnit graph is similar to the SelectionDAG, but
89 /// excludes nodes that aren't interesting to scheduling, and represents
90 /// flagged together nodes with a single SUnit.
91 virtual void BuildSchedGraph(AliasAnalysis *AA);
93 /// ComputeLatency - Compute node latency.
95 virtual void ComputeLatency(SUnit *SU);
97 virtual MachineBasicBlock *
98 EmitSchedule(DenseMap<MachineBasicBlock*, MachineBasicBlock*> *EM);
100 /// Schedule - Order nodes according to selected style, filling
101 /// in the Sequence member.
103 virtual void Schedule() = 0;
105 virtual void dumpNode(const SUnit *SU) const;
107 virtual std::string getGraphNodeLabel(const SUnit *SU) const;
109 virtual void getCustomGraphFeatures(GraphWriter<ScheduleDAG*> &GW) const;
112 /// ClusterNeighboringLoads - Cluster loads from "near" addresses into
114 void ClusterNeighboringLoads();
116 /// BuildSchedUnits, AddSchedEdges - Helper functions for BuildSchedGraph.
117 void BuildSchedUnits();
118 void AddSchedEdges();