1 //===- llvm/IR/ProfDataUtils.h - Profiling Metadata Utilities ---*- 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 // 9 /// @file 10 /// This file contains the declarations for profiling metadata utility 11 /// functions. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #ifndef LLVM_IR_PROFDATAUTILS_H 16 #define LLVM_IR_PROFDATAUTILS_H 17 18 #include "llvm/ADT/SmallVector.h" 19 #include "llvm/ADT/Twine.h" 20 #include "llvm/IR/Metadata.h" 21 22 namespace llvm { 23 24 /// Checks if an Instruction has MD_prof Metadata 25 bool hasProfMD(const Instruction &I); 26 27 /// Checks if an MDNode contains Branch Weight Metadata 28 bool isBranchWeightMD(const MDNode *ProfileData); 29 30 /// Checks if an instructions has Branch Weight Metadata 31 /// 32 /// \param I The instruction to check 33 /// \returns True if I has an MD_prof node containing Branch Weights. False 34 /// otherwise. 35 bool hasBranchWeightMD(const Instruction &I); 36 37 /// Checks if an instructions has valid Branch Weight Metadata 38 /// 39 /// \param I The instruction to check 40 /// \returns True if I has an MD_prof node containing valid Branch Weights, 41 /// i.e., one weight for each successor. False otherwise. 42 bool hasValidBranchWeightMD(const Instruction &I); 43 44 /// Get the branch weights metadata node 45 /// 46 /// \param I The Instruction to get the weights from. 47 /// \returns A pointer to I's branch weights metadata node, if it exists. 48 /// Nullptr otherwise. 49 MDNode *getBranchWeightMDNode(const Instruction &I); 50 51 /// Get the valid branch weights metadata node 52 /// 53 /// \param I The Instruction to get the weights from. 54 /// \returns A pointer to I's valid branch weights metadata node, if it exists. 55 /// Nullptr otherwise. 56 MDNode *getValidBranchWeightMDNode(const Instruction &I); 57 58 /// Check if Branch Weight Metadata has an "expected" field from an llvm.expect* 59 /// intrinsic 60 bool hasBranchWeightOrigin(const Instruction &I); 61 62 /// Check if Branch Weight Metadata has an "expected" field from an llvm.expect* 63 /// intrinsic 64 bool hasBranchWeightOrigin(const MDNode *ProfileData); 65 66 /// Return the offset to the first branch weight data 67 unsigned getBranchWeightOffset(const MDNode *ProfileData); 68 69 unsigned getNumBranchWeights(const MDNode &ProfileData); 70 71 /// Extract branch weights from MD_prof metadata 72 /// 73 /// \param ProfileData A pointer to an MDNode. 74 /// \param [out] Weights An output vector to fill with branch weights 75 /// \returns True if weights were extracted, False otherwise. When false Weights 76 /// will be cleared. 77 bool extractBranchWeights(const MDNode *ProfileData, 78 SmallVectorImpl<uint32_t> &Weights); 79 80 /// Faster version of extractBranchWeights() that skips checks and must only 81 /// be called with "branch_weights" metadata nodes. Supports uint32_t. 82 void extractFromBranchWeightMD32(const MDNode *ProfileData, 83 SmallVectorImpl<uint32_t> &Weights); 84 85 /// Faster version of extractBranchWeights() that skips checks and must only 86 /// be called with "branch_weights" metadata nodes. Supports uint64_t. 87 void extractFromBranchWeightMD64(const MDNode *ProfileData, 88 SmallVectorImpl<uint64_t> &Weights); 89 90 /// Extract branch weights attatched to an Instruction 91 /// 92 /// \param I The Instruction to extract weights from. 93 /// \param [out] Weights An output vector to fill with branch weights 94 /// \returns True if weights were extracted, False otherwise. When false Weights 95 /// will be cleared. 96 bool extractBranchWeights(const Instruction &I, 97 SmallVectorImpl<uint32_t> &Weights); 98 99 /// Extract branch weights from a conditional branch or select Instruction. 100 /// 101 /// \param I The instruction to extract branch weights from. 102 /// \param [out] TrueVal will contain the branch weight for the True branch 103 /// \param [out] FalseVal will contain the branch weight for the False branch 104 /// \returns True on success with profile weights filled in. False if no 105 /// metadata or invalid metadata was found. 106 bool extractBranchWeights(const Instruction &I, uint64_t &TrueVal, 107 uint64_t &FalseVal); 108 109 /// Retrieve the total of all weights from MD_prof data. 110 /// 111 /// \param ProfileData The profile data to extract the total weight from 112 /// \param [out] TotalWeights input variable to fill with total weights 113 /// \returns True on success with profile total weights filled in. False if no 114 /// metadata was found. 115 bool extractProfTotalWeight(const MDNode *ProfileData, uint64_t &TotalWeights); 116 117 /// Retrieve the total of all weights from an instruction. 118 /// 119 /// \param I The instruction to extract the total weight from 120 /// \param [out] TotalWeights input variable to fill with total weights 121 /// \returns True on success with profile total weights filled in. False if no 122 /// metadata was found. 123 bool extractProfTotalWeight(const Instruction &I, uint64_t &TotalWeights); 124 125 /// Create a new `branch_weights` metadata node and add or overwrite 126 /// a `prof` metadata reference to instruction `I`. 127 /// \param I the Instruction to set branch weights on. 128 /// \param Weights an array of weights to set on instruction I. 129 /// \param IsExpected were these weights added from an llvm.expect* intrinsic. 130 void setBranchWeights(Instruction &I, ArrayRef<uint32_t> Weights, 131 bool IsExpected); 132 133 /// Scaling the profile data attached to 'I' using the ratio of S/T. 134 void scaleProfData(Instruction &I, uint64_t S, uint64_t T); 135 136 } // namespace llvm 137 #endif 138