4 files changed, 25 insertions, 70 deletions

diff --git a/llvm/tools/llvm-mca/Dispatch.cpp b/llvm/tools/llvm-mca/Dispatch.cpp
index ce329b4a00d..d3efe69b89b 100644
--- a/llvm/tools/llvm-mca/Dispatch.cpp
+++ b/llvm/tools/llvm-mca/Dispatch.cpp
@@ -362,27 +362,7 @@ bool DispatchUnit::checkRCU(unsigned Index, const InstrDesc &Desc) {
 }
 
 bool DispatchUnit::checkScheduler(unsigned Index, const InstrDesc &Desc) {
-  // If this is a zero-latency instruction, then it bypasses
-  // the scheduler.
-  HWStallEvent::GenericEventType Type = HWStallEvent::Invalid;
-  switch (SC->canBeDispatched(Desc)) {
-  case Scheduler::HWS_AVAILABLE:
-    return true;
-  case Scheduler::HWS_QUEUE_UNAVAILABLE:
-    Type = HWStallEvent::SchedulerQueueFull;
-    break;
-  case Scheduler::HWS_LD_QUEUE_UNAVAILABLE:
-    Type = HWStallEvent::LoadQueueFull;
-    break;
-  case Scheduler::HWS_ST_QUEUE_UNAVAILABLE:
-    Type = HWStallEvent::StoreQueueFull;
-    break;
-  case Scheduler::HWS_DISPATCH_GROUP_RESTRICTION:
-    Type = HWStallEvent::DispatchGroupStall;
-  }
-
-  Owner->notifyStallEvent(HWStallEvent(Type, Index));
-  return false;
+  return SC->canBeDispatched(Index, Desc);
 }
 
 void DispatchUnit::updateRAWDependencies(ReadState &RS,
diff --git a/llvm/tools/llvm-mca/HWEventListener.h b/llvm/tools/llvm-mca/HWEventListener.h
index a7949121595..f6f5fc6763d 100644
--- a/llvm/tools/llvm-mca/HWEventListener.h
+++ b/llvm/tools/llvm-mca/HWEventListener.h
@@ -97,6 +97,7 @@ public:
     // Generic stall events generated by the DispatchUnit.
     RegisterFileStall,
     RetireControlUnitStall,
+    // Generic stall events generated by the Scheduler.
     DispatchGroupStall,
     SchedulerQueueFull,
     LoadQueueFull,
diff --git a/llvm/tools/llvm-mca/Scheduler.cpp b/llvm/tools/llvm-mca/Scheduler.cpp
index c77d4b81968..6d746cb5609 100644
--- a/llvm/tools/llvm-mca/Scheduler.cpp
+++ b/llvm/tools/llvm-mca/Scheduler.cpp
@@ -308,24 +308,26 @@ void Scheduler::dump() const {
 }
 #endif
 
-Scheduler::Event Scheduler::canBeDispatched(const InstrDesc &Desc) const {
+bool Scheduler::canBeDispatched(unsigned Index, const InstrDesc &Desc) const {
+  HWStallEvent::GenericEventType Type = HWStallEvent::Invalid;
+
   if (Desc.MayLoad && LSU->isLQFull())
-    return HWS_LD_QUEUE_UNAVAILABLE;
-  if (Desc.MayStore && LSU->isSQFull())
-    return HWS_ST_QUEUE_UNAVAILABLE;
-
-  Scheduler::Event Event;
-  switch (Resources->canBeDispatched(Desc.Buffers)) {
-  case ResourceStateEvent::RS_BUFFER_AVAILABLE:
-    Event = HWS_AVAILABLE;
-    break;
-  case ResourceStateEvent::RS_BUFFER_UNAVAILABLE:
-    Event = HWS_QUEUE_UNAVAILABLE;
-    break;
-  case ResourceStateEvent::RS_RESERVED:
-    Event = HWS_DISPATCH_GROUP_RESTRICTION;
+    Type = HWStallEvent::LoadQueueFull;
+  else if (Desc.MayStore && LSU->isSQFull())
+    Type = HWStallEvent::StoreQueueFull;
+  else {
+    switch (Resources->canBeDispatched(Desc.Buffers)) {
+    default: return true;
+    case ResourceStateEvent::RS_BUFFER_UNAVAILABLE:
+      Type = HWStallEvent::SchedulerQueueFull;
+      break;
+    case ResourceStateEvent::RS_RESERVED:
+      Type = HWStallEvent::DispatchGroupStall;
+    }
   }
-  return Event;
+
+  Owner->notifyStallEvent(HWStallEvent(Type, Index));
+  return false;
 }
 
 void Scheduler::issueInstruction(Instruction &IS, unsigned InstrIndex) {
diff --git a/llvm/tools/llvm-mca/Scheduler.h b/llvm/tools/llvm-mca/Scheduler.h
index ad73fc7979c..9f9422c3f1a 100644
--- a/llvm/tools/llvm-mca/Scheduler.h
+++ b/llvm/tools/llvm-mca/Scheduler.h
@@ -454,42 +454,14 @@ public:
 
   void setDispatchUnit(DispatchUnit *DispUnit) { DU = DispUnit; }
 
-  /// Scheduling events.
+  /// Check if instruction at index Idx can be dispatched.
   ///
   /// The DispatchUnit is responsible for querying the Scheduler before
   /// dispatching new instructions. Queries are performed through method
-  /// `Scheduler::CanBeDispatched`, which returns an instance of this enum to
-  /// tell if the dispatch would fail or not.  If scheduling resources are
-  /// available, and the instruction can be dispatched, then the query returns
-  /// HWS_AVAILABLE.  A values different than HWS_AVAILABLE means that the
-  /// instruction cannot be dispatched during this cycle.
-  ///
-  /// Each event name starts with prefix "HWS_", and it is followed by
-  /// a substring which describes the reason why the Scheduler was unavailable
-  /// (or "AVAILABLE" if the instruction is allowed to be dispatched).
-  ///
-  /// HWS_QUEUE_UNAVAILABLE is returned if there are not enough available slots
-  /// in the  scheduler's queue. That means, one (or more) buffered resources
-  /// consumed by the instruction were full.
-  ///
-  /// HWS_LD_QUEUE_UNAVAILABLE is returned when an instruction 'mayLoad', and
-  /// the load queue in the load/store unit (implemented by class LSUnit) is
-  /// full.  Similarly, HWS_ST_QUEUE_UNAVAILABLE is returned when the store
-  /// queue is full, and the instruction to be dispatched 'mayStore'.
-  ///
-  /// HWS_DISPATCH_GROUP_RESTRICTION is only returned in special cases where the
-  /// instruction consumes an in-order issue/dispatch resource (i.e. a resource
-  /// with `BufferSize=0`), and the pipeline resource is not immediately
-  /// available.
-  enum Event {
-    HWS_AVAILABLE,
-    HWS_QUEUE_UNAVAILABLE,
-    HWS_DISPATCH_GROUP_RESTRICTION,
-    HWS_LD_QUEUE_UNAVAILABLE,
-    HWS_ST_QUEUE_UNAVAILABLE
-  };
-
-  Event canBeDispatched(const InstrDesc &Desc) const;
+  /// `Scheduler::CanBeDispatched`. If scheduling resources are available,
+  /// and the instruction can be dispatched, then this method returns true.
+  /// Otherwise, a generic HWStallEvent is notified to the listeners.
+  bool canBeDispatched(unsigned Idx, const InstrDesc &Desc) const;
   void scheduleInstruction(unsigned Idx, Instruction &MCIS);
 
   void cycleEvent(unsigned Cycle);