1 //===--------------------- ResourcePressureView.h ---------------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 /// \file 9 /// 10 /// This file define class ResourcePressureView. 11 /// Class ResourcePressureView observes hardware events generated by 12 /// the Pipeline object and collects statistics related to resource usage at 13 /// instruction granularity. 14 /// Resource pressure information is then printed out to a stream in the 15 /// form of a table like the one from the example below: 16 /// 17 /// Resources: 18 /// [0] - JALU0 19 /// [1] - JALU1 20 /// [2] - JDiv 21 /// [3] - JFPM 22 /// [4] - JFPU0 23 /// [5] - JFPU1 24 /// [6] - JLAGU 25 /// [7] - JSAGU 26 /// [8] - JSTC 27 /// [9] - JVIMUL 28 /// 29 /// Resource pressure per iteration: 30 /// [0] [1] [2] [3] [4] [5] [6] [7] [8] [9] 31 /// 0.00 0.00 0.00 0.00 2.00 2.00 0.00 0.00 0.00 0.00 32 /// 33 /// Resource pressure by instruction: 34 /// [0] [1] [2] [3] [4] [5] [6] [7] [8] [9] Instructions: 35 /// - - - - - 1.00 - - - - vpermilpd $1, %xmm0, 36 /// %xmm1 37 /// - - - - 1.00 - - - - - vaddps %xmm0, %xmm1, 38 /// %xmm2 39 /// - - - - - 1.00 - - - - vmovshdup %xmm2, %xmm3 40 /// - - - - 1.00 - - - - - vaddss %xmm2, %xmm3, 41 /// %xmm4 42 /// 43 /// In this example, we have AVX code executed on AMD Jaguar (btver2). 44 /// Both shuffles and vector floating point add operations on XMM registers have 45 /// a reciprocal throughput of 1cy. 46 /// Each add is issued to pipeline JFPU0, while each shuffle is issued to 47 /// pipeline JFPU1. The overall pressure per iteration is reported by two 48 /// tables: the first smaller table is the resource pressure per iteration; 49 /// the second table reports resource pressure per instruction. Values are the 50 /// average resource cycles consumed by an instruction. 51 /// Every vector add from the example uses resource JFPU0 for an average of 1cy 52 /// per iteration. Consequently, the resource pressure on JFPU0 is of 2cy per 53 /// iteration. 54 /// 55 //===----------------------------------------------------------------------===// 56 57 #ifndef LLVM_TOOLS_LLVM_MCA_RESOURCEPRESSUREVIEW_H 58 #define LLVM_TOOLS_LLVM_MCA_RESOURCEPRESSUREVIEW_H 59 60 #include "Views/View.h" 61 #include "llvm/ADT/ArrayRef.h" 62 #include "llvm/ADT/DenseMap.h" 63 #include "llvm/MC/MCInst.h" 64 #include "llvm/MC/MCInstPrinter.h" 65 #include "llvm/MC/MCSubtargetInfo.h" 66 67 namespace llvm { 68 namespace mca { 69 70 /// This class collects resource pressure statistics and it is able to print 71 /// out all the collected information as a table to an output stream. 72 class ResourcePressureView : public View { 73 const llvm::MCSubtargetInfo &STI; 74 llvm::MCInstPrinter &MCIP; 75 llvm::ArrayRef<llvm::MCInst> Source; 76 unsigned LastInstructionIdx; 77 78 // Map to quickly obtain the ResourceUsage column index from a processor 79 // resource ID. 80 llvm::DenseMap<unsigned, unsigned> Resource2VecIndex; 81 82 // Table of resources used by instructions. 83 std::vector<ResourceCycles> ResourceUsage; 84 unsigned NumResourceUnits; 85 86 void printResourcePressurePerIter(llvm::raw_ostream &OS) const; 87 void printResourcePressurePerInst(llvm::raw_ostream &OS) const; 88 89 public: 90 ResourcePressureView(const llvm::MCSubtargetInfo &sti, 91 llvm::MCInstPrinter &Printer, 92 llvm::ArrayRef<llvm::MCInst> S); 93 94 void onEvent(const HWInstructionEvent &Event) override; 95 void printView(llvm::raw_ostream &OS) const override { 96 printResourcePressurePerIter(OS); 97 printResourcePressurePerInst(OS); 98 } 99 }; 100 } // namespace mca 101 } // namespace llvm 102 103 #endif 104