[llvm] r340659 - [llvm-mca] Move the ResourceManger from the Scheduler into its own file. NFC.
Matt Davis via llvm-commits
llvm-commits at lists.llvm.org
Fri Aug 24 14:53:13 PDT 2018
Author: mattd
Date: Fri Aug 24 14:53:12 2018
New Revision: 340659
URL: http://llvm.org/viewvc/llvm-project?rev=340659&view=rev
Log:
[llvm-mca] Move the ResourceManger from the Scheduler into its own file. NFC.
Added:
llvm/trunk/tools/llvm-mca/ResourceManager.cpp
llvm/trunk/tools/llvm-mca/ResourceManager.h
Modified:
llvm/trunk/tools/llvm-mca/CMakeLists.txt
llvm/trunk/tools/llvm-mca/Scheduler.cpp
llvm/trunk/tools/llvm-mca/Scheduler.h
Modified: llvm/trunk/tools/llvm-mca/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-mca/CMakeLists.txt?rev=340659&r1=340658&r2=340659&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-mca/CMakeLists.txt (original)
+++ llvm/trunk/tools/llvm-mca/CMakeLists.txt Fri Aug 24 14:53:12 2018
@@ -25,6 +25,7 @@ add_llvm_tool(llvm-mca
Pipeline.cpp
PipelinePrinter.cpp
RegisterFile.cpp
+ ResourceManager.cpp
RetireControlUnit.cpp
RetireStage.cpp
Scheduler.cpp
Added: llvm/trunk/tools/llvm-mca/ResourceManager.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-mca/ResourceManager.cpp?rev=340659&view=auto
==============================================================================
--- llvm/trunk/tools/llvm-mca/ResourceManager.cpp (added)
+++ llvm/trunk/tools/llvm-mca/ResourceManager.cpp Fri Aug 24 14:53:12 2018
@@ -0,0 +1,309 @@
+//===--------------------- ResourceManager.cpp ------------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+/// \file
+///
+/// The classes here represent processor resource units and their management
+/// strategy. These classes are managed by the Scheduler.
+///
+//===----------------------------------------------------------------------===//
+
+#include "ResourceManager.h"
+#include "Support.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
+
+namespace mca {
+
+using namespace llvm;
+
+#define DEBUG_TYPE "llvm-mca"
+ResourceStrategy::~ResourceStrategy() = default;
+
+void DefaultResourceStrategy::skipMask(uint64_t Mask) {
+ NextInSequenceMask &= (~Mask);
+ if (!NextInSequenceMask) {
+ NextInSequenceMask = ResourceUnitMask ^ RemovedFromNextInSequence;
+ RemovedFromNextInSequence = 0;
+ }
+}
+
+uint64_t DefaultResourceStrategy::select(uint64_t ReadyMask) {
+ // This method assumes that ReadyMask cannot be zero.
+ uint64_t CandidateMask = llvm::PowerOf2Floor(NextInSequenceMask);
+ while (!(ReadyMask & CandidateMask)) {
+ skipMask(CandidateMask);
+ CandidateMask = llvm::PowerOf2Floor(NextInSequenceMask);
+ }
+ return CandidateMask;
+}
+
+void DefaultResourceStrategy::used(uint64_t Mask) {
+ if (Mask > NextInSequenceMask) {
+ RemovedFromNextInSequence |= Mask;
+ return;
+ }
+ skipMask(Mask);
+}
+
+ResourceState::ResourceState(const MCProcResourceDesc &Desc, unsigned Index,
+ uint64_t Mask)
+ : ProcResourceDescIndex(Index), ResourceMask(Mask),
+ BufferSize(Desc.BufferSize) {
+ if (llvm::countPopulation(ResourceMask) > 1)
+ ResourceSizeMask = ResourceMask ^ llvm::PowerOf2Floor(ResourceMask);
+ else
+ ResourceSizeMask = (1ULL << Desc.NumUnits) - 1;
+ ReadyMask = ResourceSizeMask;
+ AvailableSlots = BufferSize == -1 ? 0U : static_cast<unsigned>(BufferSize);
+ Unavailable = false;
+}
+
+bool ResourceState::isReady(unsigned NumUnits) const {
+ return (!isReserved() || isADispatchHazard()) &&
+ llvm::countPopulation(ReadyMask) >= NumUnits;
+}
+
+ResourceStateEvent ResourceState::isBufferAvailable() const {
+ if (isADispatchHazard() && isReserved())
+ return RS_RESERVED;
+ if (!isBuffered() || AvailableSlots)
+ return RS_BUFFER_AVAILABLE;
+ return RS_BUFFER_UNAVAILABLE;
+}
+
+#ifndef NDEBUG
+void ResourceState::dump() const {
+ dbgs() << "MASK: " << ResourceMask << ", SIZE_MASK: " << ResourceSizeMask
+ << ", RDYMASK: " << ReadyMask << ", BufferSize=" << BufferSize
+ << ", AvailableSlots=" << AvailableSlots
+ << ", Reserved=" << Unavailable << '\n';
+}
+#endif
+
+static unsigned getResourceStateIndex(uint64_t Mask) {
+ return std::numeric_limits<uint64_t>::digits - llvm::countLeadingZeros(Mask);
+}
+
+static std::unique_ptr<ResourceStrategy>
+getStrategyFor(const ResourceState &RS) {
+ if (RS.isAResourceGroup() || RS.getNumUnits() > 1)
+ return llvm::make_unique<DefaultResourceStrategy>(RS.getReadyMask());
+ return std::unique_ptr<ResourceStrategy>(nullptr);
+}
+
+ResourceManager::ResourceManager(const MCSchedModel &SM)
+ : ProcResID2Mask(SM.getNumProcResourceKinds()) {
+ computeProcResourceMasks(SM, ProcResID2Mask);
+ Resources.resize(SM.getNumProcResourceKinds());
+ Strategies.resize(SM.getNumProcResourceKinds());
+
+ for (unsigned I = 0, E = SM.getNumProcResourceKinds(); I < E; ++I) {
+ uint64_t Mask = ProcResID2Mask[I];
+ unsigned Index = getResourceStateIndex(Mask);
+ Resources[Index] =
+ llvm::make_unique<ResourceState>(*SM.getProcResource(I), I, Mask);
+ Strategies[Index] = getStrategyFor(*Resources[Index]);
+ }
+}
+
+void ResourceManager::setCustomStrategyImpl(std::unique_ptr<ResourceStrategy> S,
+ uint64_t ResourceMask) {
+ unsigned Index = getResourceStateIndex(ResourceMask);
+ assert(Index < Resources.size() && "Invalid processor resource index!");
+ assert(S && "Unexpected null strategy in input!");
+ Strategies[Index] = std::move(S);
+}
+
+unsigned ResourceManager::resolveResourceMask(uint64_t Mask) const {
+ return Resources[getResourceStateIndex(Mask)]->getProcResourceID();
+}
+
+unsigned ResourceManager::getNumUnits(uint64_t ResourceID) const {
+ return Resources[getResourceStateIndex(ResourceID)]->getNumUnits();
+}
+
+// Returns the actual resource consumed by this Use.
+// First, is the primary resource ID.
+// Second, is the specific sub-resource ID.
+ResourceRef ResourceManager::selectPipe(uint64_t ResourceID) {
+ unsigned Index = getResourceStateIndex(ResourceID);
+ ResourceState &RS = *Resources[Index];
+ assert(RS.isReady() && "No available units to select!");
+
+ // Special case where RS is not a group, and it only declares a single
+ // resource unit.
+ if (!RS.isAResourceGroup() && RS.getNumUnits() == 1)
+ return std::make_pair(ResourceID, RS.getReadyMask());
+
+ uint64_t SubResourceID = Strategies[Index]->select(RS.getReadyMask());
+ if (RS.isAResourceGroup())
+ return selectPipe(SubResourceID);
+ return std::make_pair(ResourceID, SubResourceID);
+}
+
+void ResourceManager::use(const ResourceRef &RR) {
+ // Mark the sub-resource referenced by RR as used.
+ ResourceState &RS = *Resources[getResourceStateIndex(RR.first)];
+ RS.markSubResourceAsUsed(RR.second);
+ // If there are still available units in RR.first,
+ // then we are done.
+ if (RS.isReady())
+ return;
+
+ // Notify to other resources that RR.first is no longer available.
+ for (std::unique_ptr<ResourceState> &Res : Resources) {
+ ResourceState &Current = *Res;
+ if (!Current.isAResourceGroup() || Current.getResourceMask() == RR.first)
+ continue;
+
+ if (Current.containsResource(RR.first)) {
+ unsigned Index = getResourceStateIndex(Current.getResourceMask());
+ Current.markSubResourceAsUsed(RR.first);
+ Strategies[Index]->used(RR.first);
+ }
+ }
+}
+
+void ResourceManager::release(const ResourceRef &RR) {
+ ResourceState &RS = *Resources[getResourceStateIndex(RR.first)];
+ bool WasFullyUsed = !RS.isReady();
+ RS.releaseSubResource(RR.second);
+ if (!WasFullyUsed)
+ return;
+
+ for (std::unique_ptr<ResourceState> &Res : Resources) {
+ ResourceState &Current = *Res;
+ if (!Current.isAResourceGroup() || Current.getResourceMask() == RR.first)
+ continue;
+
+ if (Current.containsResource(RR.first))
+ Current.releaseSubResource(RR.first);
+ }
+}
+
+ResourceStateEvent
+ResourceManager::canBeDispatched(ArrayRef<uint64_t> Buffers) const {
+ ResourceStateEvent Result = ResourceStateEvent::RS_BUFFER_AVAILABLE;
+ for (uint64_t Buffer : Buffers) {
+ ResourceState &RS = *Resources[getResourceStateIndex(Buffer)];
+ Result = RS.isBufferAvailable();
+ if (Result != ResourceStateEvent::RS_BUFFER_AVAILABLE)
+ break;
+ }
+ return Result;
+}
+
+void ResourceManager::reserveBuffers(ArrayRef<uint64_t> Buffers) {
+ for (const uint64_t Buffer : Buffers) {
+ ResourceState &RS = *Resources[getResourceStateIndex(Buffer)];
+ assert(RS.isBufferAvailable() == ResourceStateEvent::RS_BUFFER_AVAILABLE);
+ RS.reserveBuffer();
+
+ if (RS.isADispatchHazard()) {
+ assert(!RS.isReserved());
+ RS.setReserved();
+ }
+ }
+}
+
+void ResourceManager::releaseBuffers(ArrayRef<uint64_t> Buffers) {
+ for (const uint64_t R : Buffers)
+ Resources[getResourceStateIndex(R)]->releaseBuffer();
+}
+
+bool ResourceManager::canBeIssued(const InstrDesc &Desc) const {
+ return std::all_of(Desc.Resources.begin(), Desc.Resources.end(),
+ [&](const std::pair<uint64_t, const ResourceUsage> &E) {
+ unsigned NumUnits =
+ E.second.isReserved() ? 0U : E.second.NumUnits;
+ unsigned Index = getResourceStateIndex(E.first);
+ return Resources[Index]->isReady(NumUnits);
+ });
+}
+
+// Returns true if all resources are in-order, and there is at least one
+// resource which is a dispatch hazard (BufferSize = 0).
+bool ResourceManager::mustIssueImmediately(const InstrDesc &Desc) const {
+ if (!canBeIssued(Desc))
+ return false;
+ bool AllInOrderResources = all_of(Desc.Buffers, [&](uint64_t BufferMask) {
+ unsigned Index = getResourceStateIndex(BufferMask);
+ const ResourceState &Resource = *Resources[Index];
+ return Resource.isInOrder() || Resource.isADispatchHazard();
+ });
+ if (!AllInOrderResources)
+ return false;
+
+ return any_of(Desc.Buffers, [&](uint64_t BufferMask) {
+ return Resources[getResourceStateIndex(BufferMask)]->isADispatchHazard();
+ });
+}
+
+void ResourceManager::issueInstruction(
+ const InstrDesc &Desc,
+ SmallVectorImpl<std::pair<ResourceRef, double>> &Pipes) {
+ for (const std::pair<uint64_t, ResourceUsage> &R : Desc.Resources) {
+ const CycleSegment &CS = R.second.CS;
+ if (!CS.size()) {
+ releaseResource(R.first);
+ continue;
+ }
+
+ assert(CS.begin() == 0 && "Invalid {Start, End} cycles!");
+ if (!R.second.isReserved()) {
+ ResourceRef Pipe = selectPipe(R.first);
+ use(Pipe);
+ BusyResources[Pipe] += CS.size();
+ // Replace the resource mask with a valid processor resource index.
+ const ResourceState &RS = *Resources[getResourceStateIndex(Pipe.first)];
+ Pipe.first = RS.getProcResourceID();
+ Pipes.emplace_back(
+ std::pair<ResourceRef, double>(Pipe, static_cast<double>(CS.size())));
+ } else {
+ assert((countPopulation(R.first) > 1) && "Expected a group!");
+ // Mark this group as reserved.
+ assert(R.second.isReserved());
+ reserveResource(R.first);
+ BusyResources[ResourceRef(R.first, R.first)] += CS.size();
+ }
+ }
+}
+
+void ResourceManager::cycleEvent(SmallVectorImpl<ResourceRef> &ResourcesFreed) {
+ for (std::pair<ResourceRef, unsigned> &BR : BusyResources) {
+ if (BR.second)
+ BR.second--;
+ if (!BR.second) {
+ // Release this resource.
+ const ResourceRef &RR = BR.first;
+
+ if (countPopulation(RR.first) == 1)
+ release(RR);
+
+ releaseResource(RR.first);
+ ResourcesFreed.push_back(RR);
+ }
+ }
+
+ for (const ResourceRef &RF : ResourcesFreed)
+ BusyResources.erase(RF);
+}
+
+void ResourceManager::reserveResource(uint64_t ResourceID) {
+ ResourceState &Resource = *Resources[getResourceStateIndex(ResourceID)];
+ assert(!Resource.isReserved());
+ Resource.setReserved();
+}
+
+void ResourceManager::releaseResource(uint64_t ResourceID) {
+ ResourceState &Resource = *Resources[getResourceStateIndex(ResourceID)];
+ Resource.clearReserved();
+}
+
+} // namespace mca
Added: llvm/trunk/tools/llvm-mca/ResourceManager.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-mca/ResourceManager.h?rev=340659&view=auto
==============================================================================
--- llvm/trunk/tools/llvm-mca/ResourceManager.h (added)
+++ llvm/trunk/tools/llvm-mca/ResourceManager.h Fri Aug 24 14:53:12 2018
@@ -0,0 +1,360 @@
+//===--------------------- ResourceManager.h --------------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+/// \file
+///
+/// The classes here represent processor resource units and their management
+/// strategy. These classes are managed by the Scheduler.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TOOLS_LLVM_MCA_RESOURCE_MANAGER_H
+#define LLVM_TOOLS_LLVM_MCA_RESOURCE_MANAGER_H
+
+#include "Instruction.h"
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/MC/MCSchedule.h"
+
+namespace mca {
+
+/// Used to notify the internal state of a processor resource.
+///
+/// A processor resource is available if it is not reserved, and there are
+/// available slots in the buffer. A processor resource is unavailable if it
+/// is either reserved, or the associated buffer is full. A processor resource
+/// with a buffer size of -1 is always available if it is not reserved.
+///
+/// Values of type ResourceStateEvent are returned by method
+/// ResourceState::isBufferAvailable(), which is used to query the internal
+/// state of a resource.
+///
+/// The naming convention for resource state events is:
+/// * Event names start with prefix RS_
+/// * Prefix RS_ is followed by a string describing the actual resource state.
+enum ResourceStateEvent {
+ RS_BUFFER_AVAILABLE,
+ RS_BUFFER_UNAVAILABLE,
+ RS_RESERVED
+};
+
+/// Resource allocation strategy used by hardware scheduler resources.
+class ResourceStrategy {
+ ResourceStrategy(const ResourceStrategy &) = delete;
+ ResourceStrategy &operator=(const ResourceStrategy &) = delete;
+
+public:
+ ResourceStrategy() {}
+ virtual ~ResourceStrategy();
+
+ /// Selects a processor resource unit from a ReadyMask.
+ virtual uint64_t select(uint64_t ReadyMask) = 0;
+
+ /// Called by the ResourceManager when a processor resource group, or a
+ /// processor resource with multiple units has become unavailable.
+ ///
+ /// The default strategy uses this information to bias its selection logic.
+ virtual void used(uint64_t ResourceMask) {}
+};
+
+/// Default resource allocation strategy used by processor resource groups and
+/// processor resources with multiple units.
+class DefaultResourceStrategy final : public ResourceStrategy {
+ /// A Mask of resource unit identifiers.
+ ///
+ /// There is one bit set for every available resource unit.
+ /// It defaults to the value of field ResourceSizeMask in ResourceState.
+ const unsigned ResourceUnitMask;
+
+ /// A simple round-robin selector for processor resource units.
+ /// Each bit of this mask identifies a sub resource within a group.
+ ///
+ /// As an example, lets assume that this is a default policy for a
+ /// processor resource group composed by the following three units:
+ /// ResourceA -- 0b001
+ /// ResourceB -- 0b010
+ /// ResourceC -- 0b100
+ ///
+ /// Field NextInSequenceMask is used to select the next unit from the set of
+ /// resource units. It defaults to the value of field `ResourceUnitMasks` (in
+ /// this example, it defaults to mask '0b111').
+ ///
+ /// The round-robin selector would firstly select 'ResourceC', then
+ /// 'ResourceB', and eventually 'ResourceA'. When a resource R is used, the
+ /// corresponding bit in NextInSequenceMask is cleared. For example, if
+ /// 'ResourceC' is selected, then the new value of NextInSequenceMask becomes
+ /// 0xb011.
+ ///
+ /// When NextInSequenceMask becomes zero, it is automatically reset to the
+ /// default value (i.e. ResourceUnitMask).
+ uint64_t NextInSequenceMask;
+
+ /// This field is used to track resource units that are used (i.e. selected)
+ /// by other groups other than the one associated with this strategy object.
+ ///
+ /// In LLVM processor resource groups are allowed to partially (or fully)
+ /// overlap. That means, a same unit may be visible to multiple groups.
+ /// This field keeps track of uses that have originated from outside of
+ /// this group. The idea is to bias the selection strategy, so that resources
+ /// that haven't been used by other groups get prioritized.
+ ///
+ /// The end goal is to (try to) keep the resource distribution as much uniform
+ /// as possible. By construction, this mask only tracks one-level of resource
+ /// usage. Therefore, this strategy is expected to be less accurate when same
+ /// units are used multiple times by other groups within a single round of
+ /// select.
+ ///
+ /// Note: an LRU selector would have a better accuracy at the cost of being
+ /// slightly more expensive (mostly in terms of runtime cost). Methods
+ /// 'select' and 'used', are always in the hot execution path of llvm-mca.
+ /// Therefore, a slow implementation of 'select' would have a negative impact
+ /// on the overall performance of the tool.
+ uint64_t RemovedFromNextInSequence;
+
+ void skipMask(uint64_t Mask);
+
+public:
+ DefaultResourceStrategy(uint64_t UnitMask)
+ : ResourceStrategy(), ResourceUnitMask(UnitMask),
+ NextInSequenceMask(UnitMask), RemovedFromNextInSequence(0) {}
+ virtual ~DefaultResourceStrategy() = default;
+
+ uint64_t select(uint64_t ReadyMask) override;
+ void used(uint64_t Mask) override;
+};
+
+/// A processor resource descriptor.
+///
+/// There is an instance of this class for every processor resource defined by
+/// the machine scheduling model.
+/// Objects of class ResourceState dynamically track the usage of processor
+/// resource units.
+class ResourceState {
+ /// An index to the MCProcResourceDesc entry in the processor model.
+ const unsigned ProcResourceDescIndex;
+ /// A resource mask. This is generated by the tool with the help of
+ /// function `mca::createProcResourceMasks' (see Support.h).
+ const uint64_t ResourceMask;
+
+ /// A ProcResource can have multiple units.
+ ///
+ /// For processor resource groups,
+ /// this field default to the value of field `ResourceMask`; the number of
+ /// bits set is equal to the cardinality of the group. For normal (i.e.
+ /// non-group) resources, the number of bits set in this mask is equivalent
+ /// to the number of units declared by the processor model (see field
+ /// 'NumUnits' in 'ProcResourceUnits').
+ uint64_t ResourceSizeMask;
+
+ /// A mask of ready units.
+ uint64_t ReadyMask;
+
+ /// Buffered resources will have this field set to a positive number different
+ /// than zero. A buffered resource behaves like a reservation station
+ /// implementing its own buffer for out-of-order execution.
+ ///
+ /// A BufferSize of 1 is used by scheduler resources that force in-order
+ /// execution.
+ ///
+ /// A BufferSize of 0 is used to model in-order issue/dispatch resources.
+ /// Since in-order issue/dispatch resources don't implement buffers, dispatch
+ /// events coincide with issue events.
+ /// Also, no other instruction ca be dispatched/issue while this resource is
+ /// in use. Only when all the "resource cycles" are consumed (after the issue
+ /// event), a new instruction ca be dispatched.
+ const int BufferSize;
+
+ /// Available slots in the buffer (zero, if this is not a buffered resource).
+ unsigned AvailableSlots;
+
+ /// This field is set if this resource is currently reserved.
+ ///
+ /// Resources can be reserved for a number of cycles.
+ /// Instructions can still be dispatched to reserved resources. However,
+ /// istructions dispatched to a reserved resource cannot be issued to the
+ /// underlying units (i.e. pipelines) until the resource is released.
+ bool Unavailable;
+
+ /// Checks for the availability of unit 'SubResMask' in the group.
+ bool isSubResourceReady(uint64_t SubResMask) const {
+ return ReadyMask & SubResMask;
+ }
+
+public:
+ ResourceState(const llvm::MCProcResourceDesc &Desc, unsigned Index,
+ uint64_t Mask);
+
+ unsigned getProcResourceID() const { return ProcResourceDescIndex; }
+ uint64_t getResourceMask() const { return ResourceMask; }
+ uint64_t getReadyMask() const { return ReadyMask; }
+ int getBufferSize() const { return BufferSize; }
+
+ bool isBuffered() const { return BufferSize > 0; }
+ bool isInOrder() const { return BufferSize == 1; }
+
+ /// Returns true if this is an in-order dispatch/issue resource.
+ bool isADispatchHazard() const { return BufferSize == 0; }
+ bool isReserved() const { return Unavailable; }
+
+ void setReserved() { Unavailable = true; }
+ void clearReserved() { Unavailable = false; }
+
+ /// Returs true if this resource is not reserved, and if there are at least
+ /// `NumUnits` available units.
+ bool isReady(unsigned NumUnits = 1) const;
+
+ bool isAResourceGroup() const {
+ return llvm::countPopulation(ResourceMask) > 1;
+ }
+
+ bool containsResource(uint64_t ID) const { return ResourceMask & ID; }
+
+ void markSubResourceAsUsed(uint64_t ID) {
+ assert(isSubResourceReady(ID));
+ ReadyMask ^= ID;
+ }
+
+ void releaseSubResource(uint64_t ID) {
+ assert(!isSubResourceReady(ID));
+ ReadyMask ^= ID;
+ }
+
+ unsigned getNumUnits() const {
+ return isAResourceGroup() ? 1U : llvm::countPopulation(ResourceSizeMask);
+ }
+
+ /// Checks if there is an available slot in the resource buffer.
+ ///
+ /// Returns RS_BUFFER_AVAILABLE if this is not a buffered resource, or if
+ /// there is a slot available.
+ ///
+ /// Returns RS_RESERVED if this buffered resource is a dispatch hazard, and it
+ /// is reserved.
+ ///
+ /// Returns RS_BUFFER_UNAVAILABLE if there are no available slots.
+ ResourceStateEvent isBufferAvailable() const;
+
+ /// Reserve a slot in the buffer.
+ void reserveBuffer() {
+ if (AvailableSlots)
+ AvailableSlots--;
+ }
+
+ /// Release a slot in the buffer.
+ void releaseBuffer() {
+ if (BufferSize > 0)
+ AvailableSlots++;
+ assert(AvailableSlots <= static_cast<unsigned>(BufferSize));
+ }
+
+#ifndef NDEBUG
+ void dump() const;
+#endif
+};
+
+/// A resource unit identifier.
+///
+/// This is used to identify a specific processor resource unit using a pair
+/// of indices where the 'first' index is a processor resource mask, and the
+/// 'second' index is an index for a "sub-resource" (i.e. unit).
+typedef std::pair<uint64_t, uint64_t> ResourceRef;
+
+// First: a MCProcResourceDesc index identifying a buffered resource.
+// Second: max number of buffer entries used in this resource.
+typedef std::pair<unsigned, unsigned> BufferUsageEntry;
+
+/// A resource manager for processor resource units and groups.
+///
+/// This class owns all the ResourceState objects, and it is responsible for
+/// acting on requests from a Scheduler by updating the internal state of
+/// ResourceState objects.
+/// This class doesn't know about instruction itineraries and functional units.
+/// In future, it can be extended to support itineraries too through the same
+/// public interface.
+class ResourceManager {
+ // The resource manager owns all the ResourceState.
+ std::vector<std::unique_ptr<ResourceState>> Resources;
+ std::vector<std::unique_ptr<ResourceStrategy>> Strategies;
+
+ // Keeps track of which resources are busy, and how many cycles are left
+ // before those become usable again.
+ llvm::SmallDenseMap<ResourceRef, unsigned> BusyResources;
+
+ // A table to map processor resource IDs to processor resource masks.
+ llvm::SmallVector<uint64_t, 8> ProcResID2Mask;
+
+ // Returns the actual resource unit that will be used.
+ ResourceRef selectPipe(uint64_t ResourceID);
+
+ void use(const ResourceRef &RR);
+ void release(const ResourceRef &RR);
+
+ unsigned getNumUnits(uint64_t ResourceID) const;
+
+ // Overrides the selection strategy for the processor resource with the given
+ // mask.
+ void setCustomStrategyImpl(std::unique_ptr<ResourceStrategy> S,
+ uint64_t ResourceMask);
+
+public:
+ ResourceManager(const llvm::MCSchedModel &SM);
+ virtual ~ResourceManager() = default;
+
+ // Overrides the selection strategy for the resource at index ResourceID in
+ // the MCProcResourceDesc table.
+ void setCustomStrategy(std::unique_ptr<ResourceStrategy> S,
+ unsigned ResourceID) {
+ assert(ResourceID < ProcResID2Mask.size() &&
+ "Invalid resource index in input!");
+ return setCustomStrategyImpl(std::move(S), ProcResID2Mask[ResourceID]);
+ }
+
+ // Returns RS_BUFFER_AVAILABLE if buffered resources are not reserved, and if
+ // there are enough available slots in the buffers.
+ ResourceStateEvent canBeDispatched(llvm::ArrayRef<uint64_t> Buffers) const;
+
+ // Return the processor resource identifier associated to this Mask.
+ unsigned resolveResourceMask(uint64_t Mask) const;
+
+ // Consume a slot in every buffered resource from array 'Buffers'. Resource
+ // units that are dispatch hazards (i.e. BufferSize=0) are marked as reserved.
+ void reserveBuffers(llvm::ArrayRef<uint64_t> Buffers);
+
+ // Release buffer entries previously allocated by method reserveBuffers.
+ void releaseBuffers(llvm::ArrayRef<uint64_t> Buffers);
+
+ // Reserve a processor resource. A reserved resource is not available for
+ // instruction issue until it is released.
+ void reserveResource(uint64_t ResourceID);
+
+ // Release a previously reserved processor resource.
+ void releaseResource(uint64_t ResourceID);
+
+ // Returns true if all resources are in-order, and there is at least one
+ // resource which is a dispatch hazard (BufferSize = 0).
+ bool mustIssueImmediately(const InstrDesc &Desc) const;
+
+ bool canBeIssued(const InstrDesc &Desc) const;
+
+ void issueInstruction(
+ const InstrDesc &Desc,
+ llvm::SmallVectorImpl<std::pair<ResourceRef, double>> &Pipes);
+
+ void cycleEvent(llvm::SmallVectorImpl<ResourceRef> &ResourcesFreed);
+
+#ifndef NDEBUG
+ void dump() const {
+ for (const std::unique_ptr<ResourceState> &Resource : Resources)
+ Resource->dump();
+ }
+#endif
+};
+} // namespace mca
+
+#endif // LLVM_TOOLS_LLVM_MCA_RESOURCE_MANAGER_H
Modified: llvm/trunk/tools/llvm-mca/Scheduler.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-mca/Scheduler.cpp?rev=340659&r1=340658&r2=340659&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-mca/Scheduler.cpp (original)
+++ llvm/trunk/tools/llvm-mca/Scheduler.cpp Fri Aug 24 14:53:12 2018
@@ -12,7 +12,6 @@
//===----------------------------------------------------------------------===//
#include "Scheduler.h"
-#include "Support.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
@@ -22,294 +21,11 @@ using namespace llvm;
#define DEBUG_TYPE "llvm-mca"
-ResourceStrategy::~ResourceStrategy() = default;
-
void Scheduler::initializeStrategy(std::unique_ptr<SchedulerStrategy> S) {
// Ensure we have a valid (non-null) strategy object.
Strategy = S ? std::move(S) : llvm::make_unique<DefaultSchedulerStrategy>();
}
-void DefaultResourceStrategy::skipMask(uint64_t Mask) {
- NextInSequenceMask &= (~Mask);
- if (!NextInSequenceMask) {
- NextInSequenceMask = ResourceUnitMask ^ RemovedFromNextInSequence;
- RemovedFromNextInSequence = 0;
- }
-}
-
-uint64_t DefaultResourceStrategy::select(uint64_t ReadyMask) {
- // This method assumes that ReadyMask cannot be zero.
- uint64_t CandidateMask = llvm::PowerOf2Floor(NextInSequenceMask);
- while (!(ReadyMask & CandidateMask)) {
- skipMask(CandidateMask);
- CandidateMask = llvm::PowerOf2Floor(NextInSequenceMask);
- }
- return CandidateMask;
-}
-
-void DefaultResourceStrategy::used(uint64_t Mask) {
- if (Mask > NextInSequenceMask) {
- RemovedFromNextInSequence |= Mask;
- return;
- }
- skipMask(Mask);
-}
-
-ResourceState::ResourceState(const llvm::MCProcResourceDesc &Desc,
- unsigned Index, uint64_t Mask)
- : ProcResourceDescIndex(Index), ResourceMask(Mask),
- BufferSize(Desc.BufferSize) {
- if (llvm::countPopulation(ResourceMask) > 1)
- ResourceSizeMask = ResourceMask ^ llvm::PowerOf2Floor(ResourceMask);
- else
- ResourceSizeMask = (1ULL << Desc.NumUnits) - 1;
- ReadyMask = ResourceSizeMask;
- AvailableSlots = BufferSize == -1 ? 0U : static_cast<unsigned>(BufferSize);
- Unavailable = false;
-}
-
-bool ResourceState::isReady(unsigned NumUnits) const {
- return (!isReserved() || isADispatchHazard()) &&
- llvm::countPopulation(ReadyMask) >= NumUnits;
-}
-
-ResourceStateEvent ResourceState::isBufferAvailable() const {
- if (isADispatchHazard() && isReserved())
- return RS_RESERVED;
- if (!isBuffered() || AvailableSlots)
- return RS_BUFFER_AVAILABLE;
- return RS_BUFFER_UNAVAILABLE;
-}
-
-#ifndef NDEBUG
-void ResourceState::dump() const {
- dbgs() << "MASK: " << ResourceMask << ", SIZE_MASK: " << ResourceSizeMask
- << ", RDYMASK: " << ReadyMask << ", BufferSize=" << BufferSize
- << ", AvailableSlots=" << AvailableSlots
- << ", Reserved=" << Unavailable << '\n';
-}
-#endif
-
-static unsigned getResourceStateIndex(uint64_t Mask) {
- return std::numeric_limits<uint64_t>::digits - llvm::countLeadingZeros(Mask);
-}
-
-static std::unique_ptr<ResourceStrategy>
-getStrategyFor(const ResourceState &RS) {
- if (RS.isAResourceGroup() || RS.getNumUnits() > 1)
- return llvm::make_unique<DefaultResourceStrategy>(RS.getReadyMask());
- return std::unique_ptr<ResourceStrategy>(nullptr);
-}
-
-ResourceManager::ResourceManager(const llvm::MCSchedModel &SM)
- : ProcResID2Mask(SM.getNumProcResourceKinds()) {
- computeProcResourceMasks(SM, ProcResID2Mask);
- Resources.resize(SM.getNumProcResourceKinds());
- Strategies.resize(SM.getNumProcResourceKinds());
-
- for (unsigned I = 0, E = SM.getNumProcResourceKinds(); I < E; ++I) {
- uint64_t Mask = ProcResID2Mask[I];
- unsigned Index = getResourceStateIndex(Mask);
- Resources[Index] =
- llvm::make_unique<ResourceState>(*SM.getProcResource(I), I, Mask);
- Strategies[Index] = getStrategyFor(*Resources[Index]);
- }
-}
-
-void ResourceManager::setCustomStrategyImpl(std::unique_ptr<ResourceStrategy> S,
- uint64_t ResourceMask) {
- unsigned Index = getResourceStateIndex(ResourceMask);
- assert(Index < Resources.size() && "Invalid processor resource index!");
- assert(S && "Unexpected null strategy in input!");
- Strategies[Index] = std::move(S);
-}
-
-unsigned ResourceManager::resolveResourceMask(uint64_t Mask) const {
- return Resources[getResourceStateIndex(Mask)]->getProcResourceID();
-}
-
-unsigned ResourceManager::getNumUnits(uint64_t ResourceID) const {
- return Resources[getResourceStateIndex(ResourceID)]->getNumUnits();
-}
-
-// Returns the actual resource consumed by this Use.
-// First, is the primary resource ID.
-// Second, is the specific sub-resource ID.
-ResourceRef ResourceManager::selectPipe(uint64_t ResourceID) {
- unsigned Index = getResourceStateIndex(ResourceID);
- ResourceState &RS = *Resources[Index];
- assert(RS.isReady() && "No available units to select!");
-
- // Special case where RS is not a group, and it only declares a single
- // resource unit.
- if (!RS.isAResourceGroup() && RS.getNumUnits() == 1)
- return std::make_pair(ResourceID, RS.getReadyMask());
-
- uint64_t SubResourceID = Strategies[Index]->select(RS.getReadyMask());
- if (RS.isAResourceGroup())
- return selectPipe(SubResourceID);
- return std::make_pair(ResourceID, SubResourceID);
-}
-
-void ResourceManager::use(const ResourceRef &RR) {
- // Mark the sub-resource referenced by RR as used.
- ResourceState &RS = *Resources[getResourceStateIndex(RR.first)];
- RS.markSubResourceAsUsed(RR.second);
- // If there are still available units in RR.first,
- // then we are done.
- if (RS.isReady())
- return;
-
- // Notify to other resources that RR.first is no longer available.
- for (std::unique_ptr<ResourceState> &Res : Resources) {
- ResourceState &Current = *Res;
- if (!Current.isAResourceGroup() || Current.getResourceMask() == RR.first)
- continue;
-
- if (Current.containsResource(RR.first)) {
- unsigned Index = getResourceStateIndex(Current.getResourceMask());
- Current.markSubResourceAsUsed(RR.first);
- Strategies[Index]->used(RR.first);
- }
- }
-}
-
-void ResourceManager::release(const ResourceRef &RR) {
- ResourceState &RS = *Resources[getResourceStateIndex(RR.first)];
- bool WasFullyUsed = !RS.isReady();
- RS.releaseSubResource(RR.second);
- if (!WasFullyUsed)
- return;
-
- for (std::unique_ptr<ResourceState> &Res : Resources) {
- ResourceState &Current = *Res;
- if (!Current.isAResourceGroup() || Current.getResourceMask() == RR.first)
- continue;
-
- if (Current.containsResource(RR.first))
- Current.releaseSubResource(RR.first);
- }
-}
-
-ResourceStateEvent
-ResourceManager::canBeDispatched(ArrayRef<uint64_t> Buffers) const {
- ResourceStateEvent Result = ResourceStateEvent::RS_BUFFER_AVAILABLE;
- for (uint64_t Buffer : Buffers) {
- ResourceState &RS = *Resources[getResourceStateIndex(Buffer)];
- Result = RS.isBufferAvailable();
- if (Result != ResourceStateEvent::RS_BUFFER_AVAILABLE)
- break;
- }
- return Result;
-}
-
-void ResourceManager::reserveBuffers(ArrayRef<uint64_t> Buffers) {
- for (const uint64_t Buffer : Buffers) {
- ResourceState &RS = *Resources[getResourceStateIndex(Buffer)];
- assert(RS.isBufferAvailable() == ResourceStateEvent::RS_BUFFER_AVAILABLE);
- RS.reserveBuffer();
-
- if (RS.isADispatchHazard()) {
- assert(!RS.isReserved());
- RS.setReserved();
- }
- }
-}
-
-void ResourceManager::releaseBuffers(ArrayRef<uint64_t> Buffers) {
- for (const uint64_t R : Buffers)
- Resources[getResourceStateIndex(R)]->releaseBuffer();
-}
-
-bool ResourceManager::canBeIssued(const InstrDesc &Desc) const {
- return std::all_of(Desc.Resources.begin(), Desc.Resources.end(),
- [&](const std::pair<uint64_t, const ResourceUsage> &E) {
- unsigned NumUnits =
- E.second.isReserved() ? 0U : E.second.NumUnits;
- unsigned Index = getResourceStateIndex(E.first);
- return Resources[Index]->isReady(NumUnits);
- });
-}
-
-// Returns true if all resources are in-order, and there is at least one
-// resource which is a dispatch hazard (BufferSize = 0).
-bool ResourceManager::mustIssueImmediately(const InstrDesc &Desc) const {
- if (!canBeIssued(Desc))
- return false;
- bool AllInOrderResources = all_of(Desc.Buffers, [&](uint64_t BufferMask) {
- unsigned Index = getResourceStateIndex(BufferMask);
- const ResourceState &Resource = *Resources[Index];
- return Resource.isInOrder() || Resource.isADispatchHazard();
- });
- if (!AllInOrderResources)
- return false;
-
- return any_of(Desc.Buffers, [&](uint64_t BufferMask) {
- return Resources[getResourceStateIndex(BufferMask)]->isADispatchHazard();
- });
-}
-
-void ResourceManager::issueInstruction(
- const InstrDesc &Desc,
- SmallVectorImpl<std::pair<ResourceRef, double>> &Pipes) {
- for (const std::pair<uint64_t, ResourceUsage> &R : Desc.Resources) {
- const CycleSegment &CS = R.second.CS;
- if (!CS.size()) {
- releaseResource(R.first);
- continue;
- }
-
- assert(CS.begin() == 0 && "Invalid {Start, End} cycles!");
- if (!R.second.isReserved()) {
- ResourceRef Pipe = selectPipe(R.first);
- use(Pipe);
- BusyResources[Pipe] += CS.size();
- // Replace the resource mask with a valid processor resource index.
- const ResourceState &RS = *Resources[getResourceStateIndex(Pipe.first)];
- Pipe.first = RS.getProcResourceID();
- Pipes.emplace_back(
- std::pair<ResourceRef, double>(Pipe, static_cast<double>(CS.size())));
- } else {
- assert((countPopulation(R.first) > 1) && "Expected a group!");
- // Mark this group as reserved.
- assert(R.second.isReserved());
- reserveResource(R.first);
- BusyResources[ResourceRef(R.first, R.first)] += CS.size();
- }
- }
-}
-
-void ResourceManager::cycleEvent(SmallVectorImpl<ResourceRef> &ResourcesFreed) {
- for (std::pair<ResourceRef, unsigned> &BR : BusyResources) {
- if (BR.second)
- BR.second--;
- if (!BR.second) {
- // Release this resource.
- const ResourceRef &RR = BR.first;
-
- if (countPopulation(RR.first) == 1)
- release(RR);
-
- releaseResource(RR.first);
- ResourcesFreed.push_back(RR);
- }
- }
-
- for (const ResourceRef &RF : ResourcesFreed)
- BusyResources.erase(RF);
-}
-
-void ResourceManager::reserveResource(uint64_t ResourceID) {
- ResourceState &Resource = *Resources[getResourceStateIndex(ResourceID)];
- assert(!Resource.isReserved());
- Resource.setReserved();
-}
-
-void ResourceManager::releaseResource(uint64_t ResourceID) {
- ResourceState &Resource = *Resources[getResourceStateIndex(ResourceID)];
- Resource.clearReserved();
-}
-
// Anchor the vtable of SchedulerStrategy and DefaultSchedulerStrategy.
SchedulerStrategy::~SchedulerStrategy() = default;
DefaultSchedulerStrategy::~DefaultSchedulerStrategy() = default;
Modified: llvm/trunk/tools/llvm-mca/Scheduler.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-mca/Scheduler.h?rev=340659&r1=340658&r2=340659&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-mca/Scheduler.h (original)
+++ llvm/trunk/tools/llvm-mca/Scheduler.h Fri Aug 24 14:53:12 2018
@@ -16,348 +16,13 @@
#define LLVM_TOOLS_LLVM_MCA_SCHEDULER_H
#include "HardwareUnit.h"
-#include "Instruction.h"
#include "LSUnit.h"
-#include "llvm/ADT/ArrayRef.h"
-#include "llvm/ADT/DenseMap.h"
+#include "ResourceManager.h"
#include "llvm/ADT/SmallVector.h"
-#include "llvm/MC/MCSubtargetInfo.h"
-#include <map>
+#include "llvm/MC/MCSchedule.h"
namespace mca {
-/// Used to notify the internal state of a processor resource.
-///
-/// A processor resource is available if it is not reserved, and there are
-/// available slots in the buffer. A processor resource is unavailable if it
-/// is either reserved, or the associated buffer is full. A processor resource
-/// with a buffer size of -1 is always available if it is not reserved.
-///
-/// Values of type ResourceStateEvent are returned by method
-/// ResourceState::isBufferAvailable(), which is used to query the internal
-/// state of a resource.
-///
-/// The naming convention for resource state events is:
-/// * Event names start with prefix RS_
-/// * Prefix RS_ is followed by a string describing the actual resource state.
-enum ResourceStateEvent {
- RS_BUFFER_AVAILABLE,
- RS_BUFFER_UNAVAILABLE,
- RS_RESERVED
-};
-
-/// Resource allocation strategy used by hardware scheduler resources.
-class ResourceStrategy {
- ResourceStrategy(const ResourceStrategy &) = delete;
- ResourceStrategy &operator=(const ResourceStrategy &) = delete;
-
-public:
- ResourceStrategy() {}
- virtual ~ResourceStrategy();
-
- /// Selects a processor resource unit from a ReadyMask.
- virtual uint64_t select(uint64_t ReadyMask) = 0;
-
- /// Called by the ResourceManager when a processor resource group, or a
- /// processor resource with multiple units has become unavailable.
- ///
- /// The default strategy uses this information to bias its selection logic.
- virtual void used(uint64_t ResourceMask) {}
-};
-
-/// Default resource allocation strategy used by processor resource groups and
-/// processor resources with multiple units.
-class DefaultResourceStrategy final : public ResourceStrategy {
- /// A Mask of resource unit identifiers.
- ///
- /// There is one bit set for every available resource unit.
- /// It defaults to the value of field ResourceSizeMask in ResourceState.
- const unsigned ResourceUnitMask;
-
- /// A simple round-robin selector for processor resource units.
- /// Each bit of this mask identifies a sub resource within a group.
- ///
- /// As an example, lets assume that this is a default policy for a
- /// processor resource group composed by the following three units:
- /// ResourceA -- 0b001
- /// ResourceB -- 0b010
- /// ResourceC -- 0b100
- ///
- /// Field NextInSequenceMask is used to select the next unit from the set of
- /// resource units. It defaults to the value of field `ResourceUnitMasks` (in
- /// this example, it defaults to mask '0b111').
- ///
- /// The round-robin selector would firstly select 'ResourceC', then
- /// 'ResourceB', and eventually 'ResourceA'. When a resource R is used, the
- /// corresponding bit in NextInSequenceMask is cleared. For example, if
- /// 'ResourceC' is selected, then the new value of NextInSequenceMask becomes
- /// 0xb011.
- ///
- /// When NextInSequenceMask becomes zero, it is automatically reset to the
- /// default value (i.e. ResourceUnitMask).
- uint64_t NextInSequenceMask;
-
- /// This field is used to track resource units that are used (i.e. selected)
- /// by other groups other than the one associated with this strategy object.
- ///
- /// In LLVM processor resource groups are allowed to partially (or fully)
- /// overlap. That means, a same unit may be visible to multiple groups.
- /// This field keeps track of uses that have originated from outside of
- /// this group. The idea is to bias the selection strategy, so that resources
- /// that haven't been used by other groups get prioritized.
- ///
- /// The end goal is to (try to) keep the resource distribution as much uniform
- /// as possible. By construction, this mask only tracks one-level of resource
- /// usage. Therefore, this strategy is expected to be less accurate when same
- /// units are used multiple times by other groups within a single round of
- /// select.
- ///
- /// Note: an LRU selector would have a better accuracy at the cost of being
- /// slightly more expensive (mostly in terms of runtime cost). Methods
- /// 'select' and 'used', are always in the hot execution path of llvm-mca.
- /// Therefore, a slow implementation of 'select' would have a negative impact
- /// on the overall performance of the tool.
- uint64_t RemovedFromNextInSequence;
-
- void skipMask(uint64_t Mask);
-
-public:
- DefaultResourceStrategy(uint64_t UnitMask)
- : ResourceStrategy(), ResourceUnitMask(UnitMask),
- NextInSequenceMask(UnitMask), RemovedFromNextInSequence(0) {}
- virtual ~DefaultResourceStrategy() = default;
-
- uint64_t select(uint64_t ReadyMask) override;
- void used(uint64_t Mask) override;
-};
-
-/// A processor resource descriptor.
-///
-/// There is an instance of this class for every processor resource defined by
-/// the machine scheduling model.
-/// Objects of class ResourceState dynamically track the usage of processor
-/// resource units.
-class ResourceState {
- /// An index to the MCProcResourceDesc entry in the processor model.
- const unsigned ProcResourceDescIndex;
- /// A resource mask. This is generated by the tool with the help of
- /// function `mca::createProcResourceMasks' (see Support.h).
- const uint64_t ResourceMask;
-
- /// A ProcResource can have multiple units.
- ///
- /// For processor resource groups,
- /// this field default to the value of field `ResourceMask`; the number of
- /// bits set is equal to the cardinality of the group. For normal (i.e.
- /// non-group) resources, the number of bits set in this mask is equivalent
- /// to the number of units declared by the processor model (see field
- /// 'NumUnits' in 'ProcResourceUnits').
- uint64_t ResourceSizeMask;
-
- /// A mask of ready units.
- uint64_t ReadyMask;
-
- /// Buffered resources will have this field set to a positive number different
- /// than zero. A buffered resource behaves like a reservation station
- /// implementing its own buffer for out-of-order execution.
- ///
- /// A BufferSize of 1 is used by scheduler resources that force in-order
- /// execution.
- ///
- /// A BufferSize of 0 is used to model in-order issue/dispatch resources.
- /// Since in-order issue/dispatch resources don't implement buffers, dispatch
- /// events coincide with issue events.
- /// Also, no other instruction ca be dispatched/issue while this resource is
- /// in use. Only when all the "resource cycles" are consumed (after the issue
- /// event), a new instruction ca be dispatched.
- const int BufferSize;
-
- /// Available slots in the buffer (zero, if this is not a buffered resource).
- unsigned AvailableSlots;
-
- /// This field is set if this resource is currently reserved.
- ///
- /// Resources can be reserved for a number of cycles.
- /// Instructions can still be dispatched to reserved resources. However,
- /// istructions dispatched to a reserved resource cannot be issued to the
- /// underlying units (i.e. pipelines) until the resource is released.
- bool Unavailable;
-
- /// Checks for the availability of unit 'SubResMask' in the group.
- bool isSubResourceReady(uint64_t SubResMask) const {
- return ReadyMask & SubResMask;
- }
-
-public:
- ResourceState(const llvm::MCProcResourceDesc &Desc, unsigned Index,
- uint64_t Mask);
-
- unsigned getProcResourceID() const { return ProcResourceDescIndex; }
- uint64_t getResourceMask() const { return ResourceMask; }
- uint64_t getReadyMask() const { return ReadyMask; }
- int getBufferSize() const { return BufferSize; }
-
- bool isBuffered() const { return BufferSize > 0; }
- bool isInOrder() const { return BufferSize == 1; }
-
- /// Returns true if this is an in-order dispatch/issue resource.
- bool isADispatchHazard() const { return BufferSize == 0; }
- bool isReserved() const { return Unavailable; }
-
- void setReserved() { Unavailable = true; }
- void clearReserved() { Unavailable = false; }
-
- /// Returs true if this resource is not reserved, and if there are at least
- /// `NumUnits` available units.
- bool isReady(unsigned NumUnits = 1) const;
-
- bool isAResourceGroup() const {
- return llvm::countPopulation(ResourceMask) > 1;
- }
-
- bool containsResource(uint64_t ID) const { return ResourceMask & ID; }
-
- void markSubResourceAsUsed(uint64_t ID) {
- assert(isSubResourceReady(ID));
- ReadyMask ^= ID;
- }
-
- void releaseSubResource(uint64_t ID) {
- assert(!isSubResourceReady(ID));
- ReadyMask ^= ID;
- }
-
- unsigned getNumUnits() const {
- return isAResourceGroup() ? 1U : llvm::countPopulation(ResourceSizeMask);
- }
-
- /// Checks if there is an available slot in the resource buffer.
- ///
- /// Returns RS_BUFFER_AVAILABLE if this is not a buffered resource, or if
- /// there is a slot available.
- ///
- /// Returns RS_RESERVED if this buffered resource is a dispatch hazard, and it
- /// is reserved.
- ///
- /// Returns RS_BUFFER_UNAVAILABLE if there are no available slots.
- ResourceStateEvent isBufferAvailable() const;
-
- /// Reserve a slot in the buffer.
- void reserveBuffer() {
- if (AvailableSlots)
- AvailableSlots--;
- }
-
- /// Release a slot in the buffer.
- void releaseBuffer() {
- if (BufferSize > 0)
- AvailableSlots++;
- assert(AvailableSlots <= static_cast<unsigned>(BufferSize));
- }
-
-#ifndef NDEBUG
- void dump() const;
-#endif
-};
-
-/// A resource unit identifier.
-///
-/// This is used to identify a specific processor resource unit using a pair
-/// of indices where the 'first' index is a processor resource mask, and the
-/// 'second' index is an index for a "sub-resource" (i.e. unit).
-typedef std::pair<uint64_t, uint64_t> ResourceRef;
-
-// First: a MCProcResourceDesc index identifying a buffered resource.
-// Second: max number of buffer entries used in this resource.
-typedef std::pair<unsigned, unsigned> BufferUsageEntry;
-
-/// A resource manager for processor resource units and groups.
-///
-/// This class owns all the ResourceState objects, and it is responsible for
-/// acting on requests from a Scheduler by updating the internal state of
-/// ResourceState objects.
-/// This class doesn't know about instruction itineraries and functional units.
-/// In future, it can be extended to support itineraries too through the same
-/// public interface.
-class ResourceManager {
- // The resource manager owns all the ResourceState.
- std::vector<std::unique_ptr<ResourceState>> Resources;
- std::vector<std::unique_ptr<ResourceStrategy>> Strategies;
-
- // Keeps track of which resources are busy, and how many cycles are left
- // before those become usable again.
- llvm::SmallDenseMap<ResourceRef, unsigned> BusyResources;
-
- // A table to map processor resource IDs to processor resource masks.
- llvm::SmallVector<uint64_t, 8> ProcResID2Mask;
-
- // Returns the actual resource unit that will be used.
- ResourceRef selectPipe(uint64_t ResourceID);
-
- void use(const ResourceRef &RR);
- void release(const ResourceRef &RR);
-
- unsigned getNumUnits(uint64_t ResourceID) const;
-
- // Overrides the selection strategy for the processor resource with the given
- // mask.
- void setCustomStrategyImpl(std::unique_ptr<ResourceStrategy> S,
- uint64_t ResourceMask);
-
-public:
- ResourceManager(const llvm::MCSchedModel &SM);
- virtual ~ResourceManager() = default;
-
- // Overrides the selection strategy for the resource at index ResourceID in
- // the MCProcResourceDesc table.
- void setCustomStrategy(std::unique_ptr<ResourceStrategy> S,
- unsigned ResourceID) {
- assert(ResourceID < ProcResID2Mask.size() &&
- "Invalid resource index in input!");
- return setCustomStrategyImpl(std::move(S), ProcResID2Mask[ResourceID]);
- }
-
- // Returns RS_BUFFER_AVAILABLE if buffered resources are not reserved, and if
- // there are enough available slots in the buffers.
- ResourceStateEvent canBeDispatched(llvm::ArrayRef<uint64_t> Buffers) const;
-
- // Return the processor resource identifier associated to this Mask.
- unsigned resolveResourceMask(uint64_t Mask) const;
-
- // Consume a slot in every buffered resource from array 'Buffers'. Resource
- // units that are dispatch hazards (i.e. BufferSize=0) are marked as reserved.
- void reserveBuffers(llvm::ArrayRef<uint64_t> Buffers);
-
- // Release buffer entries previously allocated by method reserveBuffers.
- void releaseBuffers(llvm::ArrayRef<uint64_t> Buffers);
-
- // Reserve a processor resource. A reserved resource is not available for
- // instruction issue until it is released.
- void reserveResource(uint64_t ResourceID);
-
- // Release a previously reserved processor resource.
- void releaseResource(uint64_t ResourceID);
-
- // Returns true if all resources are in-order, and there is at least one
- // resource which is a dispatch hazard (BufferSize = 0).
- bool mustIssueImmediately(const InstrDesc &Desc) const;
-
- bool canBeIssued(const InstrDesc &Desc) const;
-
- void issueInstruction(
- const InstrDesc &Desc,
- llvm::SmallVectorImpl<std::pair<ResourceRef, double>> &Pipes);
-
- void cycleEvent(llvm::SmallVectorImpl<ResourceRef> &ResourcesFreed);
-
-#ifndef NDEBUG
- void dump() const {
- for (const std::unique_ptr<ResourceState> &Resource : Resources)
- Resource->dump();
- }
-#endif
-}; // namespace mca
-
class SchedulerStrategy {
public:
SchedulerStrategy() = default;
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