[AMDGPU] Move common fields out of WaitcntBrackets. NFC. (llvm#148864)

WaitcntBrackets holds per-basic-block information about the state of
wait counters. It also held a bunch of fields that are constant
throughout a run of the pass. This patch moves them out into the
SIInsertWaitcnts class, for better logical separation and to save a tiny
bit of memory.

Author: jayfoad

llvm/lib/Target/AMDGPU/SIInsertWaitcnts.cpp

@@ -407,8 +407,13 @@ class WaitcntGeneratorGFX12Plus : public WaitcntGenerator {
 };
 
 class SIInsertWaitcnts {
+public:
+  const GCNSubtarget *ST;
+  InstCounterType SmemAccessCounter;
+  InstCounterType MaxCounter;
+  const unsigned *WaitEventMaskForInst;
+
 private:
-  const GCNSubtarget *ST = nullptr;
   const SIInstrInfo *TII = nullptr;
   const SIRegisterInfo *TRI = nullptr;
   const MachineRegisterInfo *MRI = nullptr;
@@ -424,8 +429,6 @@ class SIInsertWaitcnts {
     bool Dirty = true;
   };
 
-  InstCounterType SmemAccessCounter;
-
   MapVector<MachineBasicBlock *, BlockInfo> BlockInfos;
 
   bool ForceEmitWaitcnt[NUM_INST_CNTS];
@@ -442,7 +445,7 @@ class SIInsertWaitcnts {
   // message.
   DenseSet<MachineInstr *> ReleaseVGPRInsts;
 
-  InstCounterType MaxCounter = NUM_NORMAL_INST_CNTS;
+  HardwareLimits Limits;
 
 public:
   SIInsertWaitcnts(MachineLoopInfo *MLI, MachinePostDominatorTree *PDT,
@@ -453,6 +456,30 @@ class SIInsertWaitcnts {
     (void)ForceVMCounter;
   }
 
+  unsigned getWaitCountMax(InstCounterType T) const {
+    switch (T) {
+    case LOAD_CNT:
+      return Limits.LoadcntMax;
+    case DS_CNT:
+      return Limits.DscntMax;
+    case EXP_CNT:
+      return Limits.ExpcntMax;
+    case STORE_CNT:
+      return Limits.StorecntMax;
+    case SAMPLE_CNT:
+      return Limits.SamplecntMax;
+    case BVH_CNT:
+      return Limits.BvhcntMax;
+    case KM_CNT:
+      return Limits.KmcntMax;
+    case X_CNT:
+      return Limits.XcntMax;
+    default:
+      break;
+    }
+    return 0;
+  }
+
   bool shouldFlushVmCnt(MachineLoop *ML, const WaitcntBrackets &Brackets);
   bool isPreheaderToFlush(MachineBasicBlock &MBB,
                           const WaitcntBrackets &ScoreBrackets);
@@ -568,39 +595,10 @@ class SIInsertWaitcnts {
 // "s_waitcnt 0" before use.
 class WaitcntBrackets {
 public:
-  WaitcntBrackets(const GCNSubtarget *SubTarget, InstCounterType MaxCounter,
-                  HardwareLimits Limits, const unsigned *WaitEventMaskForInst,
-                  InstCounterType SmemAccessCounter)
-      : ST(SubTarget), MaxCounter(MaxCounter), Limits(Limits),
-        WaitEventMaskForInst(WaitEventMaskForInst),
-        SmemAccessCounter(SmemAccessCounter) {}
-
-  unsigned getWaitCountMax(InstCounterType T) const {
-    switch (T) {
-    case LOAD_CNT:
-      return Limits.LoadcntMax;
-    case DS_CNT:
-      return Limits.DscntMax;
-    case EXP_CNT:
-      return Limits.ExpcntMax;
-    case STORE_CNT:
-      return Limits.StorecntMax;
-    case SAMPLE_CNT:
-      return Limits.SamplecntMax;
-    case BVH_CNT:
-      return Limits.BvhcntMax;
-    case KM_CNT:
-      return Limits.KmcntMax;
-    case X_CNT:
-      return Limits.XcntMax;
-    default:
-      break;
-    }
-    return 0;
-  }
+  WaitcntBrackets(const SIInsertWaitcnts *Context) : Context(Context) {}
 
   bool isSmemCounter(InstCounterType T) const {
-    return T == SmemAccessCounter || T == X_CNT;
+    return T == Context->SmemAccessCounter || T == X_CNT;
   }
 
   unsigned getSgprScoresIdx(InstCounterType T) const {
@@ -658,7 +656,7 @@ class WaitcntBrackets {
     return PendingEvents & (1 << E);
   }
   unsigned hasPendingEvent(InstCounterType T) const {
-    unsigned HasPending = PendingEvents & WaitEventMaskForInst[T];
+    unsigned HasPending = PendingEvents & Context->WaitEventMaskForInst[T];
     assert((HasPending != 0) == (getScoreRange(T) != 0));
     return HasPending;
   }
@@ -686,7 +684,8 @@ class WaitcntBrackets {
   }
 
   unsigned getPendingGDSWait() const {
-    return std::min(getScoreUB(DS_CNT) - LastGDS, getWaitCountMax(DS_CNT) - 1);
+    return std::min(getScoreUB(DS_CNT) - LastGDS,
+                    Context->getWaitCountMax(DS_CNT) - 1);
   }
 
   void setPendingGDS() { LastGDS = ScoreUBs[DS_CNT]; }
@@ -710,8 +709,9 @@ class WaitcntBrackets {
   }
 
   void setStateOnFunctionEntryOrReturn() {
-    setScoreUB(STORE_CNT, getScoreUB(STORE_CNT) + getWaitCountMax(STORE_CNT));
-    PendingEvents |= WaitEventMaskForInst[STORE_CNT];
+    setScoreUB(STORE_CNT,
+               getScoreUB(STORE_CNT) + Context->getWaitCountMax(STORE_CNT));
+    PendingEvents |= Context->WaitEventMaskForInst[STORE_CNT];
   }
 
   ArrayRef<const MachineInstr *> getLDSDMAStores() const {
@@ -747,8 +747,8 @@ class WaitcntBrackets {
     if (T != EXP_CNT)
       return;
 
-    if (getScoreRange(EXP_CNT) > getWaitCountMax(EXP_CNT))
-      ScoreLBs[EXP_CNT] = ScoreUBs[EXP_CNT] - getWaitCountMax(EXP_CNT);
+    if (getScoreRange(EXP_CNT) > Context->getWaitCountMax(EXP_CNT))
+      ScoreLBs[EXP_CNT] = ScoreUBs[EXP_CNT] - Context->getWaitCountMax(EXP_CNT);
   }
 
   void setRegScore(int GprNo, InstCounterType T, unsigned Val) {
@@ -763,11 +763,8 @@ class WaitcntBrackets {
                          const MachineOperand &Op, InstCounterType CntTy,
                          unsigned Val);
 
-  const GCNSubtarget *ST = nullptr;
-  InstCounterType MaxCounter = NUM_EXTENDED_INST_CNTS;
-  HardwareLimits Limits = {};
-  const unsigned *WaitEventMaskForInst;
-  InstCounterType SmemAccessCounter;
+  const SIInsertWaitcnts *Context;
+
   unsigned ScoreLBs[NUM_INST_CNTS] = {0};
   unsigned ScoreUBs[NUM_INST_CNTS] = {0};
   unsigned PendingEvents = 0;
@@ -829,7 +826,7 @@ RegInterval WaitcntBrackets::getRegInterval(const MachineInstr *MI,
 
   RegInterval Result;
 
-  MCRegister MCReg = AMDGPU::getMCReg(Op.getReg(), *ST);
+  MCRegister MCReg = AMDGPU::getMCReg(Op.getReg(), *Context->ST);
   unsigned RegIdx = TRI->getHWRegIndex(MCReg);
   assert(isUInt<8>(RegIdx));
 
@@ -887,7 +884,7 @@ void WaitcntBrackets::setScoreByOperand(const MachineInstr *MI,
 // this at compile time, so we have to assume it might be applied if the
 // instruction supports it).
 bool WaitcntBrackets::hasPointSampleAccel(const MachineInstr &MI) const {
-  if (!ST->hasPointSampleAccel() || !SIInstrInfo::isMIMG(MI))
+  if (!Context->ST->hasPointSampleAccel() || !SIInstrInfo::isMIMG(MI))
     return false;
 
   const AMDGPU::MIMGInfo *Info = AMDGPU::getMIMGInfo(MI.getOpcode());
@@ -913,7 +910,7 @@ void WaitcntBrackets::updateByEvent(const SIInstrInfo *TII,
                                     const SIRegisterInfo *TRI,
                                     const MachineRegisterInfo *MRI,
                                     WaitEventType E, MachineInstr &Inst) {
-  InstCounterType T = eventCounter(WaitEventMaskForInst, E);
+  InstCounterType T = eventCounter(Context->WaitEventMaskForInst, E);
 
   unsigned UB = getScoreUB(T);
   unsigned CurrScore = UB + 1;
@@ -1082,8 +1079,10 @@ void WaitcntBrackets::updateByEvent(const SIInstrInfo *TII,
 }
 
 void WaitcntBrackets::print(raw_ostream &OS) const {
+  const GCNSubtarget *ST = Context->ST;
+
   OS << '\n';
-  for (auto T : inst_counter_types(MaxCounter)) {
+  for (auto T : inst_counter_types(Context->MaxCounter)) {
     unsigned SR = getScoreRange(T);
 
     switch (T) {
@@ -1197,7 +1196,7 @@ void WaitcntBrackets::determineWait(InstCounterType T, RegInterval Interval,
     // s_waitcnt instruction.
     if ((UB >= ScoreToWait) && (ScoreToWait > LB)) {
       if ((T == LOAD_CNT || T == DS_CNT) && hasPendingFlat() &&
-          !ST->hasFlatLgkmVMemCountInOrder()) {
+          !Context->ST->hasFlatLgkmVMemCountInOrder()) {
         // If there is a pending FLAT operation, and this is a VMem or LGKM
         // waitcnt and the target can report early completion, then we need
         // to force a waitcnt 0.
@@ -1211,7 +1210,7 @@ void WaitcntBrackets::determineWait(InstCounterType T, RegInterval Interval,
         // If a counter has been maxed out avoid overflow by waiting for
         // MAX(CounterType) - 1 instead.
         unsigned NeededWait =
-            std::min(UB - ScoreToWait, getWaitCountMax(T) - 1);
+            std::min(UB - ScoreToWait, Context->getWaitCountMax(T) - 1);
         addWait(Wait, T, NeededWait);
       }
     }
@@ -1239,7 +1238,7 @@ void WaitcntBrackets::applyWaitcnt(InstCounterType T, unsigned Count) {
     setScoreLB(T, std::max(getScoreLB(T), UB - Count));
   } else {
     setScoreLB(T, UB);
-    PendingEvents &= ~WaitEventMaskForInst[T];
+    PendingEvents &= ~Context->WaitEventMaskForInst[T];
   }
 }
 
@@ -1264,7 +1263,7 @@ void WaitcntBrackets::applyXcnt(const AMDGPU::Waitcnt &Wait) {
 // the decrement may go out of order.
 bool WaitcntBrackets::counterOutOfOrder(InstCounterType T) const {
   // Scalar memory read always can go out of order.
-  if ((T == SmemAccessCounter && hasPendingEvent(SMEM_ACCESS)) ||
+  if ((T == Context->SmemAccessCounter && hasPendingEvent(SMEM_ACCESS)) ||
       (T == X_CNT && hasPendingEvent(SMEM_GROUP)))
     return true;
   return hasMixedPendingEvents(T);
@@ -2388,8 +2387,9 @@ bool WaitcntBrackets::merge(const WaitcntBrackets &Other) {
   VgprUB = std::max(VgprUB, Other.VgprUB);
   SgprUB = std::max(SgprUB, Other.SgprUB);
 
-  for (auto T : inst_counter_types(MaxCounter)) {
+  for (auto T : inst_counter_types(Context->MaxCounter)) {
     // Merge event flags for this counter
+    const unsigned *WaitEventMaskForInst = Context->WaitEventMaskForInst;
     const unsigned OldEvents = PendingEvents & WaitEventMaskForInst[T];
     const unsigned OtherEvents = Other.PendingEvents & WaitEventMaskForInst[T];
     if (OtherEvents & ~OldEvents)
@@ -2748,11 +2748,10 @@ bool SIInsertWaitcnts::run(MachineFunction &MF) {
   for (auto T : inst_counter_types())
     ForceEmitWaitcnt[T] = false;
 
-  const unsigned *WaitEventMaskForInst = WCG->getWaitEventMask();
+  WaitEventMaskForInst = WCG->getWaitEventMask();
 
   SmemAccessCounter = eventCounter(WaitEventMaskForInst, SMEM_ACCESS);
 
-  HardwareLimits Limits = {};
   if (ST->hasExtendedWaitCounts()) {
     Limits.LoadcntMax = AMDGPU::getLoadcntBitMask(IV);
     Limits.DscntMax = AMDGPU::getDscntBitMask(IV);
@@ -2809,8 +2808,7 @@ bool SIInsertWaitcnts::run(MachineFunction &MF) {
       BuildMI(EntryBB, I, DebugLoc(), TII->get(AMDGPU::S_WAITCNT)).addImm(0);
     }
 
-    auto NonKernelInitialState = std::make_unique<WaitcntBrackets>(
-        ST, MaxCounter, Limits, WaitEventMaskForInst, SmemAccessCounter);
+    auto NonKernelInitialState = std::make_unique<WaitcntBrackets>(this);
     NonKernelInitialState->setStateOnFunctionEntryOrReturn();
     BlockInfos[&EntryBB].Incoming = std::move(NonKernelInitialState);
 
@@ -2841,15 +2839,13 @@ bool SIInsertWaitcnts::run(MachineFunction &MF) {
           *Brackets = *BI.Incoming;
       } else {
         if (!Brackets) {
-          Brackets = std::make_unique<WaitcntBrackets>(
-              ST, MaxCounter, Limits, WaitEventMaskForInst, SmemAccessCounter);
+          Brackets = std::make_unique<WaitcntBrackets>(this);
         } else {
           // Reinitialize in-place. N.B. do not do this by assigning from a
           // temporary because the WaitcntBrackets class is large and it could
           // cause this function to use an unreasonable amount of stack space.
           Brackets->~WaitcntBrackets();
-          new (Brackets.get()) WaitcntBrackets(
-              ST, MaxCounter, Limits, WaitEventMaskForInst, SmemAccessCounter);
+          new (Brackets.get()) WaitcntBrackets(this);
         }
       }