//
// 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 layter.
+// Ideally, the scheduling interface would be fully defined in the MC layer.
//
//===----------------------------------------------------------------------===//
-#ifndef LLVM_TARGET_TARGETSCHEDMODEL_H
-#define LLVM_TARGET_TARGETSCHEDMODEL_H
+#ifndef LLVM_CODEGEN_TARGETSCHEDULE_H
+#define LLVM_CODEGEN_TARGETSCHEDULE_H
-#include "llvm/MC/MCSchedule.h"
+#include "llvm/ADT/SmallVector.h"
#include "llvm/MC/MCInstrItineraries.h"
+#include "llvm/MC/MCSchedule.h"
+#include "llvm/Target/TargetSubtargetInfo.h"
namespace llvm {
InstrItineraryData InstrItins;
const TargetSubtargetInfo *STI;
const TargetInstrInfo *TII;
+
+ 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(): STI(0), TII(0) {}
+ TargetSchedModel(): SchedModel(MCSchedModel::GetDefaultSchedModel()), STI(nullptr), TII(nullptr) {}
+ /// \brief 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 MCSchedModel &sm, const TargetSubtargetInfo *sti,
const TargetInstrInfo *tii);
+ /// Return the MCSchedClassDesc for this instruction.
+ const MCSchedClassDesc *resolveSchedClass(const MachineInstr *MI) const;
+
+ /// \brief 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
+ /// \brief 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 {
- return SchedModel.hasInstrSchedModel();
+ bool hasInstrSchedModel() const;
+
+ const MCSchedModel *getMCSchedModel() const { return &SchedModel; }
+
+ /// \brief 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 cycle-to-cycle itinerary
- /// data. This models scheduling at each stage in the processor pipeline.
- bool hasInstrItineraries() const {
- return SchedModel.hasInstrItineraries();
+ /// \brief Return true if this machine model includes an instruction-level
+ /// scheduling model or cycle-to-cycle itinerary data.
+ bool hasInstrSchedModelOrItineraries() const {
+ return hasInstrSchedModel() || hasInstrItineraries();
}
+ /// \brief Identify the processor corresponding to the current subtarget.
unsigned getProcessorID() const { return SchedModel.getProcessorID(); }
+
+ /// \brief Maximum number of micro-ops that may be scheduled per cycle.
+ unsigned getIssueWidth() const { return SchedModel.IssueWidth; }
+
+ /// \brief Return the number of issue slots required for this MI.
+ unsigned getNumMicroOps(const MachineInstr *MI,
+ const MCSchedClassDesc *SC = nullptr) const;
+
+ /// \brief Get the number of kinds of resources for this target.
+ unsigned getNumProcResourceKinds() const {
+ return SchedModel.getNumProcResourceKinds();
+ }
+
+ /// \brief Get a processor resource by ID for convenience.
+ const MCProcResourceDesc *getProcResource(unsigned PIdx) const {
+ return SchedModel.getProcResource(PIdx);
+ }
+
+#ifndef NDEBUG
+ const char *getResourceName(unsigned PIdx) const {
+ if (!PIdx)
+ return "MOps";
+ return SchedModel.getProcResource(PIdx)->Name;
+ }
+#endif
+
+ typedef const MCWriteProcResEntry *ProcResIter;
+
+ // \brief 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);
+ }
+
+ /// \brief 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];
+ }
+
+ /// \brief Multiply number of micro-ops by this factor to normalize it
+ /// relative to other resources.
+ unsigned getMicroOpFactor() const {
+ return MicroOpFactor;
+ }
+
+ /// \brief 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;
+ }
+
+ /// \brief Number of micro-ops that may be buffered for OOO execution.
+ unsigned getMicroOpBufferSize() const { return SchedModel.MicroOpBufferSize; }
+
+ /// \brief 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;
+ }
+
+ /// \brief 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;
+
+ /// \brief 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(unsigned Opcode) const;
+
+ /// \brief Output dependency latency of a pair of defs of the same register.
+ ///
+ /// This is typically one cycle.
+ unsigned computeOutputLatency(const MachineInstr *DefMI, unsigned DefIdx,
+ const MachineInstr *DepMI) const;
};
} // namespace llvm