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//===--------------------- ResourcePressureView.h ---------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
/// \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 "Views/InstructionView.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCInstPrinter.h"
#include "llvm/MC/MCSubtargetInfo.h"
#include "llvm/Support/JSON.h"
namespace llvm {
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 InstructionView {
unsigned LastInstructionIdx;
// 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<ResourceCycles> ResourceUsage;
unsigned NumResourceUnits;
void printResourcePressurePerIter(llvm::raw_ostream &OS) const;
void printResourcePressurePerInst(llvm::raw_ostream &OS) const;
public:
ResourcePressureView(const llvm::MCSubtargetInfo &sti,
llvm::MCInstPrinter &Printer,
llvm::ArrayRef<llvm::MCInst> S);
void onEvent(const HWInstructionEvent &Event) override;
void printView(llvm::raw_ostream &OS) const override {
printResourcePressurePerIter(OS);
printResourcePressurePerInst(OS);
}
StringRef getNameAsString() const override { return "ResourcePressureView"; }
json::Value toJSON() const override;
};
} // namespace mca
} // namespace llvm
#endif
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