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+//===--------------------- ResourcePressureView.h ---------------*- 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 define class ResourcePressureView.
+/// Class ResourcePressureView observes hardware events generated by
+/// the Pipeline object and collects statistics related to resource usage at
+/// instruction granularity.
+/// Resource pressure information is then printed out to a stream in the
+/// form of a table like the one from the example below:
+///
+/// Resources:
+/// [0] - JALU0
+/// [1] - JALU1
+/// [2] - JDiv
+/// [3] - JFPM
+/// [4] - JFPU0
+/// [5] - JFPU1
+/// [6] - JLAGU
+/// [7] - JSAGU
+/// [8] - JSTC
+/// [9] - JVIMUL
+///
+/// Resource pressure per iteration:
+/// [0]    [1]    [2]    [3]    [4]    [5]    [6]    [7]    [8]    [9]
+/// 0.00   0.00   0.00   0.00   2.00   2.00   0.00   0.00   0.00   0.00
+///
+/// Resource pressure by instruction:
+/// [0]  [1]  [2]  [3]  [4]  [5]  [6]  [7]  [8]  [9]  Instructions:
+///  -    -    -    -    -   1.00  -    -    -    -   vpermilpd  $1,    %xmm0,
+///  %xmm1
+///  -    -    -    -   1.00  -    -    -    -    -   vaddps     %xmm0, %xmm1,
+///  %xmm2
+///  -    -    -    -    -   1.00  -    -    -    -   vmovshdup  %xmm2, %xmm3
+///  -    -    -    -   1.00  -    -    -    -    -   vaddss     %xmm2, %xmm3,
+///  %xmm4
+///
+/// In this example, we have AVX code executed on AMD Jaguar (btver2).
+/// Both shuffles and vector floating point add operations on XMM registers have
+/// a reciprocal throughput of 1cy.
+/// Each add is issued to pipeline JFPU0, while each shuffle is issued to
+/// pipeline JFPU1. The overall pressure per iteration is reported by two
+/// tables: the first smaller table is the resource pressure per iteration;
+/// the second table reports resource pressure per instruction. Values are the
+/// average resource cycles consumed by an instruction.
+/// Every vector add from the example uses resource JFPU0 for an average of 1cy
+/// per iteration. Consequently, the resource pressure on JFPU0 is of 2cy per
+/// iteration.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TOOLS_LLVM_MCA_RESOURCEPRESSUREVIEW_H
+#define LLVM_TOOLS_LLVM_MCA_RESOURCEPRESSUREVIEW_H
+
+#include "SourceMgr.h"
+#include "Views/View.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/MC/MCInstPrinter.h"
+#include "llvm/MC/MCSubtargetInfo.h"
+#include <map>
+
+namespace mca {
+
+/// This class collects resource pressure statistics and it is able to print
+/// out all the collected information as a table to an output stream.
+class ResourcePressureView : public View {
+  const llvm::MCSubtargetInfo &STI;
+  llvm::MCInstPrinter &MCIP;
+  const SourceMgr &Source;
+
+  // Map to quickly obtain the ResourceUsage column index from a processor
+  // resource ID.
+  llvm::DenseMap<unsigned, unsigned> Resource2VecIndex;
+
+  // Table of resources used by instructions.
+  std::vector<double> ResourceUsage;
+  unsigned NumResourceUnits;
+
+  const llvm::MCInst &GetMCInstFromIndex(unsigned Index) const;
+  void printResourcePressurePerIteration(llvm::raw_ostream &OS,
+                                         unsigned Executions) const;
+  void printResourcePressurePerInstruction(llvm::raw_ostream &OS,
+                                           unsigned Executions) const;
+  void initialize();
+
+public:
+  ResourcePressureView(const llvm::MCSubtargetInfo &sti,
+                       llvm::MCInstPrinter &Printer, const SourceMgr &SM)
+      : STI(sti), MCIP(Printer), Source(SM) {
+    initialize();
+  }
+
+  void onEvent(const HWInstructionEvent &Event) override;
+
+  void printView(llvm::raw_ostream &OS) const override {
+    unsigned Executions = Source.getNumIterations();
+    printResourcePressurePerIteration(OS, Executions);
+    printResourcePressurePerInstruction(OS, Executions);
+  }
+};
+} // namespace mca
+
+#endif