ScheduleDAGSDNodes.h revision 221345
1178825Sdfr//===---- ScheduleDAGSDNodes.h - SDNode Scheduling --------------*- C++ -*-===// 2178825Sdfr// 3178825Sdfr// The LLVM Compiler Infrastructure 4178825Sdfr// 5178825Sdfr// This file is distributed under the University of Illinois Open Source 6178825Sdfr// License. See LICENSE.TXT for details. 7178825Sdfr// 8178825Sdfr//===----------------------------------------------------------------------===// 9178825Sdfr// 10178825Sdfr// This file implements the ScheduleDAGSDNodes class, which implements 11178825Sdfr// scheduling for an SDNode-based dependency graph. 12178825Sdfr// 13178825Sdfr//===----------------------------------------------------------------------===// 14178825Sdfr 15178825Sdfr#ifndef SCHEDULEDAGSDNODES_H 16178825Sdfr#define SCHEDULEDAGSDNODES_H 17178825Sdfr 18178825Sdfr#include "llvm/CodeGen/ScheduleDAG.h" 19178825Sdfr#include "llvm/CodeGen/SelectionDAG.h" 20178825Sdfr 21178825Sdfrnamespace llvm { 22178825Sdfr /// ScheduleDAGSDNodes - A ScheduleDAG for scheduling SDNode-based DAGs. 23178825Sdfr /// 24178825Sdfr /// Edges between SUnits are initially based on edges in the SelectionDAG, 25178825Sdfr /// and additional edges can be added by the schedulers as heuristics. 26178825Sdfr /// SDNodes such as Constants, Registers, and a few others that are not 27178825Sdfr /// interesting to schedulers are not allocated SUnits. 28178825Sdfr /// 29178825Sdfr /// SDNodes with MVT::Glue operands are grouped along with the flagged 30178825Sdfr /// nodes into a single SUnit so that they are scheduled together. 31178825Sdfr /// 32178825Sdfr /// SDNode-based scheduling graphs do not use SDep::Anti or SDep::Output 33178825Sdfr /// edges. Physical register dependence information is not carried in 34178825Sdfr /// the DAG and must be handled explicitly by schedulers. 35178825Sdfr /// 36178825Sdfr class ScheduleDAGSDNodes : public ScheduleDAG { 37178825Sdfr public: 38178825Sdfr SelectionDAG *DAG; // DAG of the current basic block 39178825Sdfr const InstrItineraryData *InstrItins; 40178825Sdfr 41178825Sdfr explicit ScheduleDAGSDNodes(MachineFunction &mf); 42178825Sdfr 43178825Sdfr virtual ~ScheduleDAGSDNodes() {} 44178825Sdfr 45178825Sdfr /// Run - perform scheduling. 46178825Sdfr /// 47178825Sdfr void Run(SelectionDAG *dag, MachineBasicBlock *bb, 48178825Sdfr MachineBasicBlock::iterator insertPos); 49178825Sdfr 50178825Sdfr /// isPassiveNode - Return true if the node is a non-scheduled leaf. 51178825Sdfr /// 52178825Sdfr static bool isPassiveNode(SDNode *Node) { 53178825Sdfr if (isa<ConstantSDNode>(Node)) return true; 54178825Sdfr if (isa<ConstantFPSDNode>(Node)) return true; 55178825Sdfr if (isa<RegisterSDNode>(Node)) return true; 56178825Sdfr if (isa<GlobalAddressSDNode>(Node)) return true; 57178825Sdfr if (isa<BasicBlockSDNode>(Node)) return true; 58178825Sdfr if (isa<FrameIndexSDNode>(Node)) return true; 59178825Sdfr if (isa<ConstantPoolSDNode>(Node)) return true; 60178825Sdfr if (isa<JumpTableSDNode>(Node)) return true; 61178825Sdfr if (isa<ExternalSymbolSDNode>(Node)) return true; 62178825Sdfr if (isa<BlockAddressSDNode>(Node)) return true; 63178825Sdfr if (Node->getOpcode() == ISD::EntryToken || 64178825Sdfr isa<MDNodeSDNode>(Node)) return true; 65178825Sdfr return false; 66178825Sdfr } 67178825Sdfr 68178825Sdfr /// NewSUnit - Creates a new SUnit and return a ptr to it. 69178825Sdfr /// 70178825Sdfr SUnit *NewSUnit(SDNode *N); 71178825Sdfr 72178825Sdfr /// Clone - Creates a clone of the specified SUnit. It does not copy the 73178825Sdfr /// predecessors / successors info nor the temporary scheduling states. 74178825Sdfr /// 75178825Sdfr SUnit *Clone(SUnit *N); 76178825Sdfr 77178825Sdfr /// BuildSchedGraph - Build the SUnit graph from the selection dag that we 78178825Sdfr /// are input. This SUnit graph is similar to the SelectionDAG, but 79178825Sdfr /// excludes nodes that aren't interesting to scheduling, and represents 80178825Sdfr /// flagged together nodes with a single SUnit. 81178825Sdfr virtual void BuildSchedGraph(AliasAnalysis *AA); 82178825Sdfr 83178825Sdfr /// InitVRegCycleFlag - Set isVRegCycle if this node's single use is 84178825Sdfr /// CopyToReg and its only active data operands are CopyFromReg within a 85178825Sdfr /// single block loop. 86178825Sdfr /// 87178825Sdfr void InitVRegCycleFlag(SUnit *SU); 88178825Sdfr 89178825Sdfr /// InitNumRegDefsLeft - Determine the # of regs defined by this node. 90178825Sdfr /// 91178825Sdfr void InitNumRegDefsLeft(SUnit *SU); 92178825Sdfr 93178825Sdfr /// ComputeLatency - Compute node latency. 94178825Sdfr /// 95178825Sdfr virtual void ComputeLatency(SUnit *SU); 96178825Sdfr 97178825Sdfr /// ComputeOperandLatency - Override dependence edge latency using 98178825Sdfr /// operand use/def information 99178825Sdfr /// 100178825Sdfr virtual void ComputeOperandLatency(SUnit *Def, SUnit *Use, 101178825Sdfr SDep& dep) const { } 102178825Sdfr 103178825Sdfr virtual void ComputeOperandLatency(SDNode *Def, SDNode *Use, 104178825Sdfr unsigned OpIdx, SDep& dep) const; 105178825Sdfr 106178825Sdfr virtual MachineBasicBlock *EmitSchedule(); 107178825Sdfr 108178825Sdfr /// Schedule - Order nodes according to selected style, filling 109178825Sdfr /// in the Sequence member. 110178825Sdfr /// 111178825Sdfr virtual void Schedule() = 0; 112178825Sdfr 113178825Sdfr virtual void dumpNode(const SUnit *SU) const; 114178825Sdfr 115178825Sdfr virtual std::string getGraphNodeLabel(const SUnit *SU) const; 116178825Sdfr 117178825Sdfr virtual void getCustomGraphFeatures(GraphWriter<ScheduleDAG*> &GW) const; 118178825Sdfr 119178825Sdfr /// RegDefIter - In place iteration over the values defined by an 120178825Sdfr /// SUnit. This does not need copies of the iterator or any other STLisms. 121178825Sdfr /// The iterator creates itself, rather than being provided by the SchedDAG. 122178825Sdfr class RegDefIter { 123178825Sdfr const ScheduleDAGSDNodes *SchedDAG; 124178825Sdfr const SDNode *Node; 125178825Sdfr unsigned DefIdx; 126178825Sdfr unsigned NodeNumDefs; 127178825Sdfr EVT ValueType; 128178825Sdfr public: 129178825Sdfr RegDefIter(const SUnit *SU, const ScheduleDAGSDNodes *SD); 130178825Sdfr 131178825Sdfr bool IsValid() const { return Node != NULL; } 132178825Sdfr 133178825Sdfr EVT GetValue() const { 134178825Sdfr assert(IsValid() && "bad iterator"); 135178825Sdfr return ValueType; 136178825Sdfr } 137178825Sdfr 138178825Sdfr void Advance(); 139178825Sdfr private: 140178825Sdfr void InitNodeNumDefs(); 141178825Sdfr }; 142178825Sdfr 143178825Sdfr private: 144178825Sdfr /// ClusterNeighboringLoads - Cluster loads from "near" addresses into 145178825Sdfr /// combined SUnits. 146178825Sdfr void ClusterNeighboringLoads(SDNode *Node); 147178825Sdfr /// ClusterNodes - Cluster certain nodes which should be scheduled together. 148178825Sdfr /// 149178825Sdfr void ClusterNodes(); 150178825Sdfr 151178825Sdfr /// BuildSchedUnits, AddSchedEdges - Helper functions for BuildSchedGraph. 152178825Sdfr void BuildSchedUnits(); 153178825Sdfr void AddSchedEdges(); 154178825Sdfr }; 155178825Sdfr} 156178825Sdfr 157178825Sdfr#endif 158178825Sdfr