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Diffstat (limited to 'clang-r353983/include/llvm/CodeGen/TargetSchedule.h')
| -rw-r--r-- | clang-r353983/include/llvm/CodeGen/TargetSchedule.h | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/clang-r353983/include/llvm/CodeGen/TargetSchedule.h b/clang-r353983/include/llvm/CodeGen/TargetSchedule.h new file mode 100644 index 00000000..cce85c8d --- /dev/null +++ b/clang-r353983/include/llvm/CodeGen/TargetSchedule.h @@ -0,0 +1,205 @@ +//===- llvm/CodeGen/TargetSchedule.h - Sched Machine Model ------*- C++ -*-===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// +// This file defines a wrapper around MCSchedModel that allows the interface to +// benefit from information currently only available in TargetInstrInfo. +// Ideally, the scheduling interface would be fully defined in the MC layer. +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_CODEGEN_TARGETSCHEDULE_H +#define LLVM_CODEGEN_TARGETSCHEDULE_H + +#include "llvm/ADT/Optional.h" +#include "llvm/ADT/SmallVector.h" +#include "llvm/CodeGen/TargetSubtargetInfo.h" +#include "llvm/Config/llvm-config.h" +#include "llvm/MC/MCInstrItineraries.h" +#include "llvm/MC/MCSchedule.h" + +namespace llvm { + +class MachineInstr; +class TargetInstrInfo; + +/// Provide an instruction scheduling machine model to CodeGen passes. +class TargetSchedModel { + // For efficiency, hold a copy of the statically defined MCSchedModel for this + // processor. + MCSchedModel SchedModel; + InstrItineraryData InstrItins; + const TargetSubtargetInfo *STI = nullptr; + const TargetInstrInfo *TII = nullptr; + + SmallVector<unsigned, 16> ResourceFactors; + unsigned MicroOpFactor; // Multiply to normalize microops to resource units. + unsigned ResourceLCM; // Resource units per cycle. Latency normalization factor. + + unsigned computeInstrLatency(const MCSchedClassDesc &SCDesc) const; + +public: + TargetSchedModel() : SchedModel(MCSchedModel::GetDefaultSchedModel()) {} + + /// Initialize the machine model for instruction scheduling. + /// + /// The machine model API keeps a copy of the top-level MCSchedModel table + /// indices and may query TargetSubtargetInfo and TargetInstrInfo to resolve + /// dynamic properties. + void init(const TargetSubtargetInfo *TSInfo); + + /// Return the MCSchedClassDesc for this instruction. + const MCSchedClassDesc *resolveSchedClass(const MachineInstr *MI) const; + + /// TargetSubtargetInfo getter. + const TargetSubtargetInfo *getSubtargetInfo() const { return STI; } + + /// TargetInstrInfo getter. + const TargetInstrInfo *getInstrInfo() const { return TII; } + + /// Return true if this machine model includes an instruction-level + /// scheduling model. + /// + /// This is more detailed than the course grain IssueWidth and default + /// latency properties, but separate from the per-cycle itinerary data. + bool hasInstrSchedModel() const; + + const MCSchedModel *getMCSchedModel() const { return &SchedModel; } + + /// Return true if this machine model includes cycle-to-cycle itinerary + /// data. + /// + /// This models scheduling at each stage in the processor pipeline. + bool hasInstrItineraries() const; + + const InstrItineraryData *getInstrItineraries() const { + if (hasInstrItineraries()) + return &InstrItins; + return nullptr; + } + + /// Return true if this machine model includes an instruction-level + /// scheduling model or cycle-to-cycle itinerary data. + bool hasInstrSchedModelOrItineraries() const { + return hasInstrSchedModel() || hasInstrItineraries(); + } + + /// Identify the processor corresponding to the current subtarget. + unsigned getProcessorID() const { return SchedModel.getProcessorID(); } + + /// Maximum number of micro-ops that may be scheduled per cycle. + unsigned getIssueWidth() const { return SchedModel.IssueWidth; } + + /// Return true if new group must begin. + bool mustBeginGroup(const MachineInstr *MI, + const MCSchedClassDesc *SC = nullptr) const; + /// Return true if current group must end. + bool mustEndGroup(const MachineInstr *MI, + const MCSchedClassDesc *SC = nullptr) const; + + /// Return the number of issue slots required for this MI. + unsigned getNumMicroOps(const MachineInstr *MI, + const MCSchedClassDesc *SC = nullptr) const; + + /// Get the number of kinds of resources for this target. + unsigned getNumProcResourceKinds() const { + return SchedModel.getNumProcResourceKinds(); + } + + /// Get a processor resource by ID for convenience. + const MCProcResourceDesc *getProcResource(unsigned PIdx) const { + return SchedModel.getProcResource(PIdx); + } + +#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) + const char *getResourceName(unsigned PIdx) const { + if (!PIdx) + return "MOps"; + return SchedModel.getProcResource(PIdx)->Name; + } +#endif + + using ProcResIter = const MCWriteProcResEntry *; + + // Get an iterator into the processor resources consumed by this + // scheduling class. + ProcResIter getWriteProcResBegin(const MCSchedClassDesc *SC) const { + // The subtarget holds a single resource table for all processors. + return STI->getWriteProcResBegin(SC); + } + ProcResIter getWriteProcResEnd(const MCSchedClassDesc *SC) const { + return STI->getWriteProcResEnd(SC); + } + + /// Multiply the number of units consumed for a resource by this factor + /// to normalize it relative to other resources. + unsigned getResourceFactor(unsigned ResIdx) const { + return ResourceFactors[ResIdx]; + } + + /// Multiply number of micro-ops by this factor to normalize it + /// relative to other resources. + unsigned getMicroOpFactor() const { + return MicroOpFactor; + } + + /// Multiply cycle count by this factor to normalize it relative to + /// other resources. This is the number of resource units per cycle. + unsigned getLatencyFactor() const { + return ResourceLCM; + } + + /// Number of micro-ops that may be buffered for OOO execution. + unsigned getMicroOpBufferSize() const { return SchedModel.MicroOpBufferSize; } + + /// Number of resource units that may be buffered for OOO execution. + /// \return The buffer size in resource units or -1 for unlimited. + int getResourceBufferSize(unsigned PIdx) const { + return SchedModel.getProcResource(PIdx)->BufferSize; + } + + /// Compute operand latency based on the available machine model. + /// + /// Compute and return the latency of the given data dependent def and use + /// when the operand indices are already known. UseMI may be NULL for an + /// unknown user. + unsigned computeOperandLatency(const MachineInstr *DefMI, unsigned DefOperIdx, + const MachineInstr *UseMI, unsigned UseOperIdx) + const; + + /// Compute the instruction latency based on the available machine + /// model. + /// + /// Compute and return the expected latency of this instruction independent of + /// a particular use. computeOperandLatency is the preferred API, but this is + /// occasionally useful to help estimate instruction cost. + /// + /// If UseDefaultDefLatency is false and no new machine sched model is + /// present this method falls back to TII->getInstrLatency with an empty + /// instruction itinerary (this is so we preserve the previous behavior of the + /// if converter after moving it to TargetSchedModel). + unsigned computeInstrLatency(const MachineInstr *MI, + bool UseDefaultDefLatency = true) const; + unsigned computeInstrLatency(const MCInst &Inst) const; + unsigned computeInstrLatency(unsigned Opcode) const; + + + /// Output dependency latency of a pair of defs of the same register. + /// + /// This is typically one cycle. + unsigned computeOutputLatency(const MachineInstr *DefMI, unsigned DefOperIdx, + const MachineInstr *DepMI) const; + + /// Compute the reciprocal throughput of the given instruction. + double computeReciprocalThroughput(const MachineInstr *MI) const; + double computeReciprocalThroughput(const MCInst &MI) const; + double computeReciprocalThroughput(unsigned Opcode) const; +}; + +} // end namespace llvm + +#endif // LLVM_CODEGEN_TARGETSCHEDULE_H |
