[llvm-mca] Turn InstructionTables into a Stage.

Summary:
This patch converts the InstructionTables class into a subclass of mca::Stage.  This change allows us to use the Stage's inherited Listeners for event notifications.  This also allows us to create a simple pipeline for viewing the InstructionTables report.

I have been working on a follow on patch that should cleanup addView in InstructionTables.  Right now, addView adds the view to both the Listener list and Views list.  The follow-on patch addresses the fact that we don't really need two lists in this case.  That change is not specific to just InstructionTables, so it will be a separate patch. 

Reviewers: andreadb, courbet, RKSimon

Reviewed By: andreadb

Subscribers: tschuett, gbedwell, llvm-commits

Differential Revision: https://reviews.llvm.org/D49329

llvm-svn: 337113

1 files changed, 39 insertions, 54 deletions

diff --git a/llvm/tools/llvm-mca/InstructionTables.cpp b/llvm/tools/llvm-mca/InstructionTables.cpp
index c7cce7cafa0..9b9dbc37fbd 100644
--- a/llvm/tools/llvm-mca/InstructionTables.cpp
+++ b/llvm/tools/llvm-mca/InstructionTables.cpp
@@ -8,9 +8,9 @@
 //===----------------------------------------------------------------------===//
 /// \file
 ///
-/// This file implements method InstructionTables::run().
-/// Method run() prints a theoretical resource pressure distribution based on
-/// the information available in the scheduling model, and without running
+/// This file implements the method InstructionTables::execute().
+/// Method execute() prints a theoretical resource pressure distribution based
+/// on the information available in the scheduling model, and without running
 /// the pipeline.
 ///
 //===----------------------------------------------------------------------===//
@@ -21,65 +21,50 @@ namespace mca {
 
 using namespace llvm;
 
-using ResourceRef = std::pair<uint64_t, uint64_t>;
-
-void InstructionTables::run() {
+bool InstructionTables::execute(InstRef &IR) {
   ArrayRef<uint64_t> Masks = IB.getProcResourceMasks();
-  SmallVector<std::pair<ResourceRef, double>, 4> UsedResources;
+  const InstrDesc &Desc = IR.getInstruction()->getDesc();
+  UsedResources.clear();
 
-  // Create an instruction descriptor for every instruction in the sequence.
-  while (S.hasNext()) {
-    UsedResources.clear();
-    SourceRef SR = S.peekNext();
-    std::unique_ptr<Instruction> Inst = IB.createInstruction(*SR.second);
-    const InstrDesc &Desc = Inst->getDesc();
-    // Now identify the resources consumed by this instruction.
-    for (const std::pair<uint64_t, ResourceUsage> Resource : Desc.Resources) {
-      // Skip zero-cycle resources (i.e. unused resources).
-      if (!Resource.second.size())
-        continue;
-      double Cycles = static_cast<double>(Resource.second.size());
-      unsigned Index = std::distance(
-          Masks.begin(), std::find(Masks.begin(), Masks.end(), Resource.first));
-      const MCProcResourceDesc &ProcResource = *SM.getProcResource(Index);
-      unsigned NumUnits = ProcResource.NumUnits;
-      if (!ProcResource.SubUnitsIdxBegin) {
-        // The number of cycles consumed by each unit.
-        Cycles /= NumUnits;
-        for (unsigned I = 0, E = NumUnits; I < E; ++I) {
-          ResourceRef ResourceUnit = std::make_pair(Index, 1U << I);
-          UsedResources.emplace_back(std::make_pair(ResourceUnit, Cycles));
-        }
-        continue;
+  // Identify the resources consumed by this instruction.
+  for (const std::pair<uint64_t, ResourceUsage> Resource : Desc.Resources) {
+    // Skip zero-cycle resources (i.e., unused resources).
+    if (!Resource.second.size())
+      continue;
+    double Cycles = static_cast<double>(Resource.second.size());
+    unsigned Index = std::distance(
+        Masks.begin(), std::find(Masks.begin(), Masks.end(), Resource.first));
+    const MCProcResourceDesc &ProcResource = *SM.getProcResource(Index);
+    unsigned NumUnits = ProcResource.NumUnits;
+    if (!ProcResource.SubUnitsIdxBegin) {
+      // The number of cycles consumed by each unit.
+      Cycles /= NumUnits;
+      for (unsigned I = 0, E = NumUnits; I < E; ++I) {
+        ResourceRef ResourceUnit = std::make_pair(Index, 1U << I);
+        UsedResources.emplace_back(std::make_pair(ResourceUnit, Cycles));
       }
+      continue;
+    }
 
-      // This is a group. Obtain the set of resources contained in this
-      // group. Some of these resources may implement multiple units.
-      // Uniformly distribute Cycles across all of the units.
-      for (unsigned I1 = 0; I1 < NumUnits; ++I1) {
-        unsigned SubUnitIdx = ProcResource.SubUnitsIdxBegin[I1];
-        const MCProcResourceDesc &SubUnit = *SM.getProcResource(SubUnitIdx);
-        // Compute the number of cycles consumed by each resource unit.
-        double RUCycles = Cycles / (NumUnits * SubUnit.NumUnits);
-        for (unsigned I2 = 0, E2 = SubUnit.NumUnits; I2 < E2; ++I2) {
-          ResourceRef ResourceUnit = std::make_pair(SubUnitIdx, 1U << I2);
-          UsedResources.emplace_back(std::make_pair(ResourceUnit, RUCycles));
-        }
+    // This is a group. Obtain the set of resources contained in this
+    // group. Some of these resources may implement multiple units.
+    // Uniformly distribute Cycles across all of the units.
+    for (unsigned I1 = 0; I1 < NumUnits; ++I1) {
+      unsigned SubUnitIdx = ProcResource.SubUnitsIdxBegin[I1];
+      const MCProcResourceDesc &SubUnit = *SM.getProcResource(SubUnitIdx);
+      // Compute the number of cycles consumed by each resource unit.
+      double RUCycles = Cycles / (NumUnits * SubUnit.NumUnits);
+      for (unsigned I2 = 0, E2 = SubUnit.NumUnits; I2 < E2; ++I2) {
+        ResourceRef ResourceUnit = std::make_pair(SubUnitIdx, 1U << I2);
+        UsedResources.emplace_back(std::make_pair(ResourceUnit, RUCycles));
       }
     }
-
-    // Now send a fake instruction issued event to all the views.
-    InstRef IR(SR.first, Inst.get());
-    HWInstructionIssuedEvent Event(IR, UsedResources);
-    for (std::unique_ptr<View> &Listener : Views)
-      Listener->onEvent(Event);
-    S.updateNext();
   }
-}
 
-void InstructionTables::printReport(llvm::raw_ostream &OS) const {
-  for (const std::unique_ptr<View> &V : Views)
-    V->printView(OS);
+  // Send a fake instruction issued event to all the views.
+  HWInstructionIssuedEvent Event(IR, UsedResources);
+  notifyEvent<HWInstructionIssuedEvent>(Event);
+  return true;
 }
 
 } // namespace mca