[llvm-mca] Move the logic that prints scheduler statistics from BackendStatistics to its own view.

Added flag -scheduler-stats to print scheduler related statistics.

llvm-svn: 329792
diff --git a/llvm/tools/llvm-mca/SchedulerStatistics.cpp b/llvm/tools/llvm-mca/SchedulerStatistics.cpp
new file mode 100644
index 0000000..28a34de
--- /dev/null
+++ b/llvm/tools/llvm-mca/SchedulerStatistics.cpp
@@ -0,0 +1,92 @@
+//===--------------------- SchedulerStatistics.cpp --------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+/// \file
+///
+/// This file implements the SchedulerStatistics interface.
+///
+//===----------------------------------------------------------------------===//
+
+#include "SchedulerStatistics.h"
+#include "llvm/Support/Format.h"
+
+using namespace llvm;
+
+namespace mca {
+
+void SchedulerStatistics::onInstructionEvent(const HWInstructionEvent &Event) {
+  if (Event.Type == HWInstructionEvent::Issued)
+    ++NumIssued;
+}
+
+void SchedulerStatistics::onReservedBuffers(ArrayRef<unsigned> Buffers) {
+  for (const unsigned Buffer : Buffers) {
+    if (BufferedResources.find(Buffer) != BufferedResources.end()) {
+      BufferUsage &BU = BufferedResources[Buffer];
+      BU.SlotsInUse++;
+      BU.MaxUsedSlots = std::max(BU.MaxUsedSlots, BU.SlotsInUse);
+      continue;
+    }
+
+    BufferedResources.insert(
+        std::pair<unsigned, BufferUsage>(Buffer, {1U, 1U}));
+  }
+}
+
+void SchedulerStatistics::onReleasedBuffers(ArrayRef<unsigned> Buffers) {
+  for (const unsigned Buffer : Buffers) {
+    assert(BufferedResources.find(Buffer) != BufferedResources.end() &&
+           "Buffered resource not in map?");
+    BufferUsage &BU = BufferedResources[Buffer];
+    BU.SlotsInUse--;
+  }
+}
+
+void SchedulerStatistics::printSchedulerStatistics(llvm::raw_ostream &OS) const {
+  std::string Buffer;
+  raw_string_ostream TempStream(Buffer);
+  TempStream << "\n\nSchedulers - number of cycles where we saw N instructions "
+                "issued:\n";
+  TempStream << "[# issued], [# cycles]\n";
+  for (const std::pair<unsigned, unsigned> &Entry : IssuedPerCycle) {
+    TempStream << " " << Entry.first << ",          " << Entry.second << "  ("
+               << format("%.1f", ((double)Entry.second / NumCycles) * 100)
+               << "%)\n";
+  }
+
+  TempStream.flush();
+  OS << Buffer;
+}
+
+void SchedulerStatistics::printSchedulerUsage(raw_ostream &OS,
+                                            const MCSchedModel &SM) const {
+  std::string Buffer;
+  raw_string_ostream TempStream(Buffer);
+  TempStream << "\n\nScheduler's queue usage:\n";
+  // Early exit if no buffered resources were consumed.
+  if (BufferedResources.empty()) {
+    TempStream << "No scheduler resources used.\n";
+    TempStream.flush();
+    OS << Buffer;
+    return;
+  }
+
+  for (unsigned I = 0, E = SM.getNumProcResourceKinds(); I < E; ++I) {
+    const MCProcResourceDesc &ProcResource = *SM.getProcResource(I);
+    if (ProcResource.BufferSize <= 0)
+      continue;
+
+    const BufferUsage &BU = BufferedResources.lookup(I);
+    TempStream << ProcResource.Name << ",  " << BU.MaxUsedSlots << '/'
+               << ProcResource.BufferSize << '\n';
+  }
+
+  TempStream.flush();
+  OS << Buffer;
+}
+} // namespace mca