X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FMC%2FMCSchedule.h;h=d7f9b69a9a2cc30132ee6d33b88940af15293c15;hb=dc0de228e265ffa060bc05227a8d18fffee89a02;hp=41bdb02f61527724d1d6b03d0a0c83b0646ddbfe;hpb=97d552e5c71dd45e1a124e5a87550270a20a9062;p=oota-llvm.git diff --git a/include/llvm/MC/MCSchedule.h b/include/llvm/MC/MCSchedule.h index 41bdb02f615..d7f9b69a9a2 100644 --- a/include/llvm/MC/MCSchedule.h +++ b/include/llvm/MC/MCSchedule.h @@ -12,8 +12,8 @@ // //===----------------------------------------------------------------------===// -#ifndef LLVM_MC_MCSCHEDMODEL_H -#define LLVM_MC_MCSCHEDMODEL_H +#ifndef LLVM_MC_MCSCHEDULE_H +#define LLVM_MC_MCSCHEDULE_H #include "llvm/Support/DataTypes.h" #include @@ -27,11 +27,26 @@ struct MCProcResourceDesc { #ifndef NDEBUG const char *Name; #endif - unsigned Count; // Number of resource of this kind + unsigned NumUnits; // Number of resource of this kind unsigned SuperIdx; // Index of the resources kind that contains this kind. + // Number of resources that may be buffered. + // + // Buffered resources (BufferSize != 0) may be consumed at some indeterminate + // cycle after dispatch. This should be used for out-of-order cpus when + // instructions that use this resource can be buffered in a reservaton + // station. + // + // Unbuffered resources (BufferSize == 0) always consume their resource some + // fixed number of cycles after dispatch. If a resource is unbuffered, then + // the scheduler will avoid scheduling instructions with conflicting resources + // in the same cycle. This is for in-order cpus, or the in-order portion of + // an out-of-order cpus. + int BufferSize; + bool operator==(const MCProcResourceDesc &Other) const { - return Count == Other.Count && SuperIdx == Other.SuperIdx; + return NumUnits == Other.NumUnits && SuperIdx == Other.SuperIdx + && BufferSize == Other.BufferSize; } }; @@ -47,10 +62,12 @@ struct MCWriteProcResEntry { }; /// Specify the latency in cpu cycles for a particular scheduling class and def -/// index. Also identify the WriteResources of this def. When the operand -/// expands to a sequence of writes, this ID is the last write in the sequence. +/// index. -1 indicates an invalid latency. Heuristics would typically consider +/// an instruction with invalid latency to have infinite latency. Also identify +/// the WriteResources of this def. When the operand expands to a sequence of +/// writes, this ID is the last write in the sequence. struct MCWriteLatencyEntry { - unsigned Cycles; + int Cycles; unsigned WriteResourceID; bool operator==(const MCWriteLatencyEntry &Other) const { @@ -112,41 +129,40 @@ struct MCSchedClassDesc { /// microarchitecture to the scheduler in the form of properties. It also /// optionally refers to scheduler resource tables and itinerary /// tables. Scheduler resource tables model the latency and cost for each -/// instruction type. Itinerary tables are an independant mechanism that +/// instruction type. Itinerary tables are an independent mechanism that /// provides a detailed reservation table describing each cycle of instruction /// execution. Subtargets may define any or all of the above categories of data /// depending on the type of CPU and selected scheduler. -class MCSchedModel { -public: - static MCSchedModel DefaultSchedModel; // For unknown processors. - +struct MCSchedModel { // IssueWidth is the maximum number of instructions that may be scheduled in // the same per-cycle group. unsigned IssueWidth; static const unsigned DefaultIssueWidth = 1; - // MinLatency is the minimum latency between a register write - // followed by a data dependent read. This determines which - // instructions may be scheduled in the same per-cycle group. This - // is distinct from *expected* latency, which determines the likely - // critical path but does not guarantee a pipeline - // hazard. MinLatency can always be overridden by the number of - // InstrStage cycles. + // MicroOpBufferSize is the number of micro-ops that the processor may buffer + // for out-of-order execution. // - // (-1) Standard in-order processor. - // Use InstrItinerary OperandCycles as MinLatency. - // If no OperandCycles exist, then use the cycle of the last InstrStage. + // "0" means operations that are not ready in this cycle are not considered + // for scheduling (they go in the pending queue). Latency is paramount. This + // may be more efficient if many instructions are pending in a schedule. // - // (0) Out-of-order processor, or in-order with bundled dependencies. - // RAW dependencies may be dispatched in the same cycle. - // Optional InstrItinerary OperandCycles provides expected latency. + // "1" means all instructions are considered for scheduling regardless of + // whether they are ready in this cycle. Latency still causes issue stalls, + // but we balance those stalls against other heuristics. // - // (>0) In-order processor with variable latencies. - // Use the greater of this value or the cycle of the last InstrStage. - // Optional InstrItinerary OperandCycles provides expected latency. - // TODO: can't yet specify both min and expected latency per operand. - int MinLatency; - static const unsigned DefaultMinLatency = -1; + // "> 1" means the processor is out-of-order. This is a machine independent + // estimate of highly machine specific characteristics such as the register + // renaming pool and reorder buffer. + unsigned MicroOpBufferSize; + static const unsigned DefaultMicroOpBufferSize = 0; + + // LoopMicroOpBufferSize is the number of micro-ops that the processor may + // buffer for optimized loop execution. More generally, this represents the + // optimal number of micro-ops in a loop body. A loop may be partially + // unrolled to bring the count of micro-ops in the loop body closer to this + // number. + unsigned LoopMicroOpBufferSize; + static const unsigned DefaultLoopMicroOpBufferSize = 0; // LoadLatency is the expected latency of load instructions. // @@ -168,7 +184,10 @@ public: unsigned MispredictPenalty; static const unsigned DefaultMispredictPenalty = 10; -private: + bool PostRAScheduler; // default value is false + + bool CompleteModel; + unsigned ProcID; const MCProcResourceDesc *ProcResourceTable; const MCSchedClassDesc *SchedClassTable; @@ -178,38 +197,22 @@ private: friend class InstrItineraryData; const InstrItinerary *InstrItineraries; -public: - // Default's must be specified as static const literals so that tablegenerated - // target code can use it in static initializers. The defaults need to be - // initialized in this default ctor because some clients directly instantiate - // MCSchedModel instead of using a generated itinerary. - MCSchedModel(): IssueWidth(DefaultIssueWidth), - MinLatency(DefaultMinLatency), - LoadLatency(DefaultLoadLatency), - HighLatency(DefaultHighLatency), - MispredictPenalty(DefaultMispredictPenalty), - ProcID(0), ProcResourceTable(0), SchedClassTable(0), - NumProcResourceKinds(0), NumSchedClasses(0), - InstrItineraries(0) { - (void)NumProcResourceKinds; - (void)NumSchedClasses; - } - - // Table-gen driven ctor. - MCSchedModel(unsigned iw, int ml, unsigned ll, unsigned hl, unsigned mp, - unsigned pi, const MCProcResourceDesc *pr, - const MCSchedClassDesc *sc, unsigned npr, unsigned nsc, - const InstrItinerary *ii): - IssueWidth(iw), MinLatency(ml), LoadLatency(ll), HighLatency(hl), - MispredictPenalty(mp), ProcID(pi), ProcResourceTable(pr), - SchedClassTable(sc), NumProcResourceKinds(npr), NumSchedClasses(nsc), - InstrItineraries(ii) {} - unsigned getProcessorID() const { return ProcID; } /// Does this machine model include instruction-level scheduling. bool hasInstrSchedModel() const { return SchedClassTable; } + /// Return true if this machine model data for all instructions with a + /// scheduling class (itinerary class or SchedRW list). + bool isComplete() const { return CompleteModel; } + + /// Return true if machine supports out of order execution. + bool isOutOfOrder() const { return MicroOpBufferSize > 1; } + + unsigned getNumProcResourceKinds() const { + return NumProcResourceKinds; + } + const MCProcResourceDesc *getProcResource(unsigned ProcResourceIdx) const { assert(hasInstrSchedModel() && "No scheduling machine model"); @@ -223,6 +226,10 @@ public: assert(SchedClassIdx < NumSchedClasses && "bad scheduling class idx"); return &SchedClassTable[SchedClassIdx]; } + + /// Returns the default initialized model. + static const MCSchedModel &GetDefaultSchedModel() { return Default; } + static const MCSchedModel Default; }; } // End llvm namespace