Home | History | Annotate | Download | only in llvm-mca 
      1 //===----------------------- HWEventListener.h ------------------*- C++ -*-===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 /// \file
     10 ///
     11 /// This file defines the main interface for hardware event listeners.
     12 ///
     13 //===----------------------------------------------------------------------===//
     14 
     15 #ifndef LLVM_TOOLS_LLVM_MCA_HWEVENTLISTENER_H
     16 #define LLVM_TOOLS_LLVM_MCA_HWEVENTLISTENER_H
     17 
     18 #include "Instruction.h"
     19 #include "llvm/ADT/ArrayRef.h"
     20 #include <utility>
     21 
     22 namespace mca {
     23 
     24 // An HWInstructionEvent represents state changes of instructions that
     25 // listeners might be interested in. Listeners can choose to ignore any event
     26 // they are not interested in.
     27 class HWInstructionEvent {
     28 public:
     29   // This is the list of event types that are shared by all targets, that
     30   // generic subtarget-agnostic classes (e.g., Pipeline, HWInstructionEvent,
     31   // ...) and generic Views can manipulate.
     32   // Subtargets are free to define additional event types, that are goin to be
     33   // handled by generic components as opaque values, but can still be
     34   // emitted by subtarget-specific pipeline stages (e.g., ExecuteStage,
     35   // DispatchStage, ...) and interpreted by subtarget-specific EventListener
     36   // implementations.
     37   enum GenericEventType {
     38     Invalid = 0,
     39     // Events generated by the Retire Control Unit.
     40     Retired,
     41     // Events generated by the Scheduler.
     42     Ready,
     43     Issued,
     44     Executed,
     45     // Events generated by the Dispatch logic.
     46     Dispatched,
     47 
     48     LastGenericEventType,
     49   };
     50 
     51   HWInstructionEvent(unsigned type, const InstRef &Inst)
     52       : Type(type), IR(Inst) {}
     53 
     54   // The event type. The exact meaning depends on the subtarget.
     55   const unsigned Type;
     56 
     57   // The instruction this event was generated for.
     58   const InstRef &IR;
     59 };
     60 
     61 class HWInstructionIssuedEvent : public HWInstructionEvent {
     62 public:
     63   using ResourceRef = std::pair<uint64_t, uint64_t>;
     64   HWInstructionIssuedEvent(const InstRef &IR,
     65                            llvm::ArrayRef<std::pair<ResourceRef, double>> UR)
     66       : HWInstructionEvent(HWInstructionEvent::Issued, IR), UsedResources(UR) {}
     67 
     68   llvm::ArrayRef<std::pair<ResourceRef, double>> UsedResources;
     69 };
     70 
     71 class HWInstructionDispatchedEvent : public HWInstructionEvent {
     72 public:
     73   HWInstructionDispatchedEvent(const InstRef &IR, llvm::ArrayRef<unsigned> Regs)
     74       : HWInstructionEvent(HWInstructionEvent::Dispatched, IR),
     75         UsedPhysRegs(Regs) {}
     76   // Number of physical register allocated for this instruction. There is one
     77   // entry per register file.
     78   llvm::ArrayRef<unsigned> UsedPhysRegs;
     79 };
     80 
     81 class HWInstructionRetiredEvent : public HWInstructionEvent {
     82 public:
     83   HWInstructionRetiredEvent(const InstRef &IR, llvm::ArrayRef<unsigned> Regs)
     84       : HWInstructionEvent(HWInstructionEvent::Retired, IR),
     85         FreedPhysRegs(Regs) {}
     86   // Number of register writes that have been architecturally committed. There
     87   // is one entry per register file.
     88   llvm::ArrayRef<unsigned> FreedPhysRegs;
     89 };
     90 
     91 // A HWStallEvent represents a pipeline stall caused by the lack of hardware
     92 // resources.
     93 class HWStallEvent {
     94 public:
     95   enum GenericEventType {
     96     Invalid = 0,
     97     // Generic stall events generated by the DispatchStage.
     98     RegisterFileStall,
     99     RetireControlUnitStall,
    100     // Generic stall events generated by the Scheduler.
    101     DispatchGroupStall,
    102     SchedulerQueueFull,
    103     LoadQueueFull,
    104     StoreQueueFull,
    105     LastGenericEvent
    106   };
    107 
    108   HWStallEvent(unsigned type, const InstRef &Inst) : Type(type), IR(Inst) {}
    109 
    110   // The exact meaning of the stall event type depends on the subtarget.
    111   const unsigned Type;
    112 
    113   // The instruction this event was generated for.
    114   const InstRef &IR;
    115 };
    116 
    117 class HWEventListener {
    118 public:
    119   // Generic events generated by the pipeline.
    120   virtual void onCycleBegin() {}
    121   virtual void onCycleEnd() {}
    122 
    123   virtual void onEvent(const HWInstructionEvent &Event) {}
    124   virtual void onEvent(const HWStallEvent &Event) {}
    125 
    126   using ResourceRef = std::pair<uint64_t, uint64_t>;
    127   virtual void onResourceAvailable(const ResourceRef &RRef) {}
    128 
    129   // Events generated by the Scheduler when buffered resources are
    130   // consumed/freed.
    131   virtual void onReservedBuffers(llvm::ArrayRef<unsigned> Buffers) {}
    132   virtual void onReleasedBuffers(llvm::ArrayRef<unsigned> Buffers) {}
    133 
    134   virtual ~HWEventListener() {}
    135 
    136 private:
    137   virtual void anchor();
    138 };
    139 } // namespace mca
    140 
    141 #endif
    142