1 //===--------------------- BottleneckAnalysis.cpp ---------------*- C++ -*-===//
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
13 //===----------------------------------------------------------------------===//
23 #define DEBUG_TYPE "llvm-mca"
80     uint64_t Current = CumulativeMask & (-CumulativeMask);  in updateResourcePressureDistribution()
93       uint64_t SubUnit = Mask & (-Mask);  in updateResourcePressureDistribution()
156     OS << " - REGISTER: ";  in dumpDependencyEdge()
159     OS << " - MEMORY";  in dumpDependencyEdge()
163     OS << " - RESOURCE MASK: " << DE.ResourceOrRegID;  in dumpDependencyEdge()
165   OS << " - COST: " << DE.Cost << '\n';  in dumpDependencyEdge()
173     // Use a cut-off threshold to prune edges with a low frequency.  in pruneEdges()
181       Nodes[Edge.ToIID].NumPredecessors--;  in pruneEdges()
182       std::swap(Edge, N.OutgoingEdges[E - 1]);  in pruneEdges()
183       --E;  in pruneEdges()
188       N.OutgoingEdges.resize(Size - NumPruned);  in pruneEdges()
209   // Each node of the graph starts with an initial default cost of zero.  The  in propagateThroughEdges()
210   // cost of a node is a measure of criticality: the higher the cost, the bigger  in propagateThroughEdges()
212   // For register and memory dependencies, the cost is a function of the write  in propagateThroughEdges()
214   // For processor resource dependencies, the cost is a function of the resource  in propagateThroughEdges()
215   // pressure. Resource interferences with low frequency values are ignored.  in propagateThroughEdges()
219   // nodes`, and then propagates the cost of N to all its neighbors.  in propagateThroughEdges()
241         uint64_t Cost = N.Cost + DepEdge.Dep.Cost;  in propagateThroughEdges()  local
243         // case, update the total cost of the destination node (ToIID), as well  in propagateThroughEdges()
245         if (Cost > To.Cost) {  in propagateThroughEdges()
247           To.Cost = Cost;  in propagateThroughEdges()
266   // Identify the node N with the highest cost in the graph. By construction,  in getCriticalSequence()
275         return Lhs.Cost < Rhs.Cost;  in getCriticalSequence()
325     FOS << "\n +----< " << FromIID << ".";  in printCriticalSequence()
335     FOS << "\n +----< " << CurrentIID << ".";  in printCriticalSequence()
341     ToIID = DE->ToIID % Source.size();  in printCriticalSequence()
351       FOS << "\n +----> " << ToIID << ".";  in printCriticalSequence()
355           << "\n +----> " << ToIID << ".";  in printCriticalSequence()
360     const DependencyEdge::Dependency &Dep = DE->Dep;  in printCriticalSequence()
382       FOS << " [ probability: " << ((DE->Frequency * 100) / Iterations)  in printCriticalSequence()
433     It->Dep.Cost += Dep.Cost;  in addDependency()
434     It->Frequency++;  in addDependency()
454                                         unsigned RegID, unsigned Cost) {  in addRegisterDep()  argument
458     DG.addRegisterDep(From, To + SourceSize, RegID, Cost);  in addRegisterDep()
459     DG.addRegisterDep(From + SourceSize, To + (SourceSize * 2), RegID, Cost);  in addRegisterDep()
462   DG.addRegisterDep(From + SourceSize, To + SourceSize, RegID, Cost);  in addRegisterDep()
466                                       unsigned Cost) {  in addMemoryDep()  argument
470     DG.addMemoryDep(From, To + SourceSize, Cost);  in addMemoryDep()
471     DG.addMemoryDep(From + SourceSize, To + (SourceSize * 2), Cost);  in addMemoryDep()
474   DG.addMemoryDep(From + SourceSize, To + SourceSize, Cost);  in addMemoryDep()
478                                         uint64_t Mask, unsigned Cost) {  in addResourceDep()  argument
482     DG.addResourceDep(From, To + SourceSize, Mask, Cost);  in addResourceDep()
483     DG.addResourceDep(From + SourceSize, To + (SourceSize * 2), Mask, Cost);  in addResourceDep()
486   DG.addResourceDep(From + SourceSize, To + SourceSize, Mask, Cost);  in addResourceDep()
511     uint64_t Current = ResourceMask & (-ResourceMask);  in onEvent()
537   if (IID == ((Iterations * Source.size()) - 1))  in onEvent()
619         OS << "\n  - " << PRDesc.Name << "  [ "  in printBottleneckHints()
627   OS << "\n  - Register Dependencies [ "  in printBottleneckHints()
630   OS << "\n  - Memory Dependencies   [ "  in printBottleneckHints()