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::Glue 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
39 const InstrItineraryData *InstrItins;
41 explicit ScheduleDAGSDNodes(MachineFunction &mf);
43 virtual ~ScheduleDAGSDNodes() {}
45 /// Run - perform scheduling.
47 void Run(SelectionDAG *dag, MachineBasicBlock *bb,
48 MachineBasicBlock::iterator insertPos);
50 /// isPassiveNode - Return true if the node is a non-scheduled leaf.
52 static bool isPassiveNode(SDNode *Node) {
53 if (isa<ConstantSDNode>(Node)) return true;
54 if (isa<ConstantFPSDNode>(Node)) return true;
55 if (isa<RegisterSDNode>(Node)) return true;
56 if (isa<RegisterMaskSDNode>(Node)) return true;
57 if (isa<GlobalAddressSDNode>(Node)) return true;
58 if (isa<BasicBlockSDNode>(Node)) return true;
59 if (isa<FrameIndexSDNode>(Node)) return true;
60 if (isa<ConstantPoolSDNode>(Node)) return true;
61 if (isa<JumpTableSDNode>(Node)) return true;
62 if (isa<ExternalSymbolSDNode>(Node)) return true;
63 if (isa<BlockAddressSDNode>(Node)) return true;
64 if (Node->getOpcode() == ISD::EntryToken ||
65 isa<MDNodeSDNode>(Node)) return true;
69 /// NewSUnit - Creates a new SUnit and return a ptr to it.
71 SUnit *NewSUnit(SDNode *N);
73 /// Clone - Creates a clone of the specified SUnit. It does not copy the
74 /// predecessors / successors info nor the temporary scheduling states.
76 SUnit *Clone(SUnit *N);
78 /// BuildSchedGraph - Build the SUnit graph from the selection dag that we
79 /// are input. This SUnit graph is similar to the SelectionDAG, but
80 /// excludes nodes that aren't interesting to scheduling, and represents
81 /// flagged together nodes with a single SUnit.
82 void BuildSchedGraph(AliasAnalysis *AA);
84 /// InitVRegCycleFlag - Set isVRegCycle if this node's single use is
85 /// CopyToReg and its only active data operands are CopyFromReg within a
86 /// single block loop.
88 void InitVRegCycleFlag(SUnit *SU);
90 /// InitNumRegDefsLeft - Determine the # of regs defined by this node.
92 void InitNumRegDefsLeft(SUnit *SU);
94 /// ComputeLatency - Compute node latency.
96 virtual void ComputeLatency(SUnit *SU);
98 /// ComputeOperandLatency - Override dependence edge latency using
99 /// operand use/def information
101 virtual void ComputeOperandLatency(SUnit *Def, SUnit *Use,
104 virtual void ComputeOperandLatency(SDNode *Def, SDNode *Use,
105 unsigned OpIdx, SDep& dep) const;
107 virtual MachineBasicBlock *EmitSchedule();
109 /// Schedule - Order nodes according to selected style, filling
110 /// in the Sequence member.
112 virtual void Schedule() = 0;
114 virtual void dumpNode(const SUnit *SU) const;
116 virtual std::string getGraphNodeLabel(const SUnit *SU) const;
118 virtual std::string getDAGName() const;
120 virtual void getCustomGraphFeatures(GraphWriter<ScheduleDAG*> &GW) const;
122 /// RegDefIter - In place iteration over the values defined by an
123 /// SUnit. This does not need copies of the iterator or any other STLisms.
124 /// The iterator creates itself, rather than being provided by the SchedDAG.
126 const ScheduleDAGSDNodes *SchedDAG;
129 unsigned NodeNumDefs;
132 RegDefIter(const SUnit *SU, const ScheduleDAGSDNodes *SD);
134 bool IsValid() const { return Node != NULL; }
136 EVT GetValue() const {
137 assert(IsValid() && "bad iterator");
141 const SDNode *GetNode() const {
145 unsigned GetIdx() const {
151 void InitNodeNumDefs();
155 /// ClusterNeighboringLoads - Cluster loads from "near" addresses into
157 void ClusterNeighboringLoads(SDNode *Node);
158 /// ClusterNodes - Cluster certain nodes which should be scheduled together.
162 /// BuildSchedUnits, AddSchedEdges - Helper functions for BuildSchedGraph.
163 void BuildSchedUnits();
164 void AddSchedEdges();