llvm/lib/IR/ProfileSummary.cpp

   1 //=-- Profilesummary.cpp - Profile summary support --------------------------=//
   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 // This file contains support for converting profile summary data from/to
  10 // metadata.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/IR/ProfileSummary.h"
  15 #include "llvm/IR/Attributes.h"
  16 #include "llvm/IR/Constants.h"
  17 #include "llvm/IR/Function.h"
  18 #include "llvm/IR/Metadata.h"
  19 #include "llvm/IR/Type.h"
  20 #include "llvm/Support/Casting.h"
  21 #include "llvm/Support/Format.h"
  22
  23 using namespace llvm;
  24
  25 // Return an MDTuple with two elements. The first element is a string Key and
  26 // the second is a uint64_t Value.
  27 static Metadata *getKeyValMD(LLVMContext &Context, const char *Key,
  28                              uint64_t Val) {
  29   Type *Int64Ty = Type::getInt64Ty(Context);
  30   Metadata *Ops[2] = {MDString::get(Context, Key),
  31                       ConstantAsMetadata::get(ConstantInt::get(Int64Ty, Val))};
  32   return MDTuple::get(Context, Ops);
  33 }
  34
  35 static Metadata *getKeyFPValMD(LLVMContext &Context, const char *Key,
  36                                double Val) {
  37   Type *DoubleTy = Type::getDoubleTy(Context);
  38   Metadata *Ops[2] = {MDString::get(Context, Key),
  39                       ConstantAsMetadata::get(ConstantFP::get(DoubleTy, Val))};
  40   return MDTuple::get(Context, Ops);
  41 }
  42
  43 // Return an MDTuple with two elements. The first element is a string Key and
  44 // the second is a string Value.
  45 static Metadata *getKeyValMD(LLVMContext &Context, const char *Key,
  46                              const char *Val) {
  47   Metadata *Ops[2] = {MDString::get(Context, Key), MDString::get(Context, Val)};
  48   return MDTuple::get(Context, Ops);
  49 }
  50
  51 // This returns an MDTuple representing the detiled summary. The tuple has two
  52 // elements: a string "DetailedSummary" and an MDTuple representing the value
  53 // of the detailed summary. Each element of this tuple is again an MDTuple whose
  54 // elements are the (Cutoff, MinCount, NumCounts) triplet of the
  55 // DetailedSummaryEntry.
  56 Metadata *ProfileSummary::getDetailedSummaryMD(LLVMContext &Context) {
  57   std::vector<Metadata *> Entries;
  58   Type *Int32Ty = Type::getInt32Ty(Context);
  59   Type *Int64Ty = Type::getInt64Ty(Context);
  60   for (auto &Entry : DetailedSummary) {
  61     Metadata *EntryMD[3] = {
  62         ConstantAsMetadata::get(ConstantInt::get(Int32Ty, Entry.Cutoff)),
  63         ConstantAsMetadata::get(ConstantInt::get(Int64Ty, Entry.MinCount)),
  64         ConstantAsMetadata::get(ConstantInt::get(Int32Ty, Entry.NumCounts))};
  65     Entries.push_back(MDTuple::get(Context, EntryMD));
  66   }
  67   Metadata *Ops[2] = {MDString::get(Context, "DetailedSummary"),
  68                       MDTuple::get(Context, Entries)};
  69   return MDTuple::get(Context, Ops);
  70 }
  71
  72 // This returns an MDTuple representing this ProfileSummary object. The first
  73 // entry of this tuple is another MDTuple of two elements: a string
  74 // "ProfileFormat" and a string representing the format ("InstrProf" or
  75 // "SampleProfile"). The rest of the elements of the outer MDTuple are specific
  76 // to the kind of profile summary as returned by getFormatSpecificMD.
  77 // IsPartialProfile is an optional field and \p AddPartialField will decide
  78 // whether to add a field for it.
  79 // PartialProfileRatio is an optional field and \p AddPartialProfileRatioField
  80 // will decide whether to add a field for it.
  81 Metadata *ProfileSummary::getMD(LLVMContext &Context, bool AddPartialField,
  82                                 bool AddPartialProfileRatioField) {
  83   const char *KindStr[3] = {"InstrProf", "CSInstrProf", "SampleProfile"};
  84   SmallVector<Metadata *, 16> Components;
  85   Components.push_back(getKeyValMD(Context, "ProfileFormat", KindStr[PSK]));
  86   Components.push_back(getKeyValMD(Context, "TotalCount", getTotalCount()));
  87   Components.push_back(getKeyValMD(Context, "MaxCount", getMaxCount()));
  88   Components.push_back(
  89       getKeyValMD(Context, "MaxInternalCount", getMaxInternalCount()));
  90   Components.push_back(
  91       getKeyValMD(Context, "MaxFunctionCount", getMaxFunctionCount()));
  92   Components.push_back(getKeyValMD(Context, "NumCounts", getNumCounts()));
  93   Components.push_back(getKeyValMD(Context, "NumFunctions", getNumFunctions()));
  94   if (AddPartialField)
  95     Components.push_back(
  96         getKeyValMD(Context, "IsPartialProfile", isPartialProfile()));
  97   if (AddPartialProfileRatioField)
  98     Components.push_back(getKeyFPValMD(Context, "PartialProfileRatio",
  99                                        getPartialProfileRatio()));
 100   Components.push_back(getDetailedSummaryMD(Context));
 101   return MDTuple::get(Context, Components);
 102 }
 103
 104 // Get the value metadata for the input MD/Key.
 105 static ConstantAsMetadata *getValMD(MDTuple *MD, const char *Key) {
 106   if (!MD)
 107     return nullptr;
 108   if (MD->getNumOperands() != 2)
 109     return nullptr;
 110   MDString *KeyMD = dyn_cast<MDString>(MD->getOperand(0));
 111   ConstantAsMetadata *ValMD = dyn_cast<ConstantAsMetadata>(MD->getOperand(1));
 112   if (!KeyMD || !ValMD)
 113     return nullptr;
 114   if (!KeyMD->getString().equals(Key))
 115     return nullptr;
 116   return ValMD;
 117 }
 118
 119 // Parse an MDTuple representing (Key, Val) pair.
 120 static bool getVal(MDTuple *MD, const char *Key, uint64_t &Val) {
 121   if (auto *ValMD = getValMD(MD, Key)) {
 122     Val = cast<ConstantInt>(ValMD->getValue())->getZExtValue();
 123     return true;
 124   }
 125   return false;
 126 }
 127
 128 static bool getVal(MDTuple *MD, const char *Key, double &Val) {
 129   if (auto *ValMD = getValMD(MD, Key)) {
 130     Val = cast<ConstantFP>(ValMD->getValue())->getValueAPF().convertToDouble();
 131     return true;
 132   }
 133   return false;
 134 }
 135
 136 // Check if an MDTuple represents a (Key, Val) pair.
 137 static bool isKeyValuePair(MDTuple *MD, const char *Key, const char *Val) {
 138   if (!MD || MD->getNumOperands() != 2)
 139     return false;
 140   MDString *KeyMD = dyn_cast<MDString>(MD->getOperand(0));
 141   MDString *ValMD = dyn_cast<MDString>(MD->getOperand(1));
 142   if (!KeyMD || !ValMD)
 143     return false;
 144   if (!KeyMD->getString().equals(Key) || !ValMD->getString().equals(Val))
 145     return false;
 146   return true;
 147 }
 148
 149 // Parse an MDTuple representing detailed summary.
 150 static bool getSummaryFromMD(MDTuple *MD, SummaryEntryVector &Summary) {
 151   if (!MD || MD->getNumOperands() != 2)
 152     return false;
 153   MDString *KeyMD = dyn_cast<MDString>(MD->getOperand(0));
 154   if (!KeyMD || !KeyMD->getString().equals("DetailedSummary"))
 155     return false;
 156   MDTuple *EntriesMD = dyn_cast<MDTuple>(MD->getOperand(1));
 157   if (!EntriesMD)
 158     return false;
 159   for (auto &&MDOp : EntriesMD->operands()) {
 160     MDTuple *EntryMD = dyn_cast<MDTuple>(MDOp);
 161     if (!EntryMD || EntryMD->getNumOperands() != 3)
 162       return false;
 163     ConstantAsMetadata *Op0 =
 164         dyn_cast<ConstantAsMetadata>(EntryMD->getOperand(0));
 165     ConstantAsMetadata *Op1 =
 166         dyn_cast<ConstantAsMetadata>(EntryMD->getOperand(1));
 167     ConstantAsMetadata *Op2 =
 168         dyn_cast<ConstantAsMetadata>(EntryMD->getOperand(2));
 169
 170     if (!Op0 || !Op1 || !Op2)
 171       return false;
 172     Summary.emplace_back(cast<ConstantInt>(Op0->getValue())->getZExtValue(),
 173                          cast<ConstantInt>(Op1->getValue())->getZExtValue(),
 174                          cast<ConstantInt>(Op2->getValue())->getZExtValue());
 175   }
 176   return true;
 177 }
 178
 179 // Get the value of an optional field. Increment 'Idx' if it was present. Return
 180 // true if we can move onto the next field.
 181 template <typename ValueType>
 182 static bool getOptionalVal(MDTuple *Tuple, unsigned &Idx, const char *Key,
 183                            ValueType &Value) {
 184   if (getVal(dyn_cast<MDTuple>(Tuple->getOperand(Idx)), Key, Value)) {
 185     Idx++;
 186     // Need to make sure when the key is present, we won't step over the bound
 187     // of Tuple operand array. Since (non-optional) DetailedSummary always comes
 188     // last, the next entry in the tuple operand array must exist.
 189     return Idx < Tuple->getNumOperands();
 190   }
 191   // It was absent, keep going.
 192   return true;
 193 }
 194
 195 ProfileSummary *ProfileSummary::getFromMD(Metadata *MD) {
 196   MDTuple *Tuple = dyn_cast_or_null<MDTuple>(MD);
 197   if (!Tuple || Tuple->getNumOperands() < 8 || Tuple->getNumOperands() > 10)
 198     return nullptr;
 199
 200   unsigned I = 0;
 201   auto &FormatMD = Tuple->getOperand(I++);
 202   ProfileSummary::Kind SummaryKind;
 203   if (isKeyValuePair(dyn_cast_or_null<MDTuple>(FormatMD), "ProfileFormat",
 204                      "SampleProfile"))
 205     SummaryKind = PSK_Sample;
 206   else if (isKeyValuePair(dyn_cast_or_null<MDTuple>(FormatMD), "ProfileFormat",
 207                           "InstrProf"))
 208     SummaryKind = PSK_Instr;
 209   else if (isKeyValuePair(dyn_cast_or_null<MDTuple>(FormatMD), "ProfileFormat",
 210                           "CSInstrProf"))
 211     SummaryKind = PSK_CSInstr;
 212   else
 213     return nullptr;
 214
 215   uint64_t NumCounts, TotalCount, NumFunctions, MaxFunctionCount, MaxCount,
 216       MaxInternalCount;
 217   if (!getVal(dyn_cast<MDTuple>(Tuple->getOperand(I++)), "TotalCount",
 218               TotalCount))
 219     return nullptr;
 220   if (!getVal(dyn_cast<MDTuple>(Tuple->getOperand(I++)), "MaxCount", MaxCount))
 221     return nullptr;
 222   if (!getVal(dyn_cast<MDTuple>(Tuple->getOperand(I++)), "MaxInternalCount",
 223               MaxInternalCount))
 224     return nullptr;
 225   if (!getVal(dyn_cast<MDTuple>(Tuple->getOperand(I++)), "MaxFunctionCount",
 226               MaxFunctionCount))
 227     return nullptr;
 228   if (!getVal(dyn_cast<MDTuple>(Tuple->getOperand(I++)), "NumCounts",
 229               NumCounts))
 230     return nullptr;
 231   if (!getVal(dyn_cast<MDTuple>(Tuple->getOperand(I++)), "NumFunctions",
 232               NumFunctions))
 233     return nullptr;
 234
 235   // Optional fields. Need to initialize because the fields are optional.
 236   uint64_t IsPartialProfile = 0;
 237   if (!getOptionalVal(Tuple, I, "IsPartialProfile", IsPartialProfile))
 238     return nullptr;
 239   double PartialProfileRatio = 0;
 240   if (!getOptionalVal(Tuple, I, "PartialProfileRatio", PartialProfileRatio))
 241     return nullptr;
 242
 243   SummaryEntryVector Summary;
 244   if (!getSummaryFromMD(dyn_cast<MDTuple>(Tuple->getOperand(I++)), Summary))
 245     return nullptr;
 246   return new ProfileSummary(SummaryKind, std::move(Summary), TotalCount,
 247                             MaxCount, MaxInternalCount, MaxFunctionCount,
 248                             NumCounts, NumFunctions, IsPartialProfile,
 249                             PartialProfileRatio);
 250 }
 251
 252 void ProfileSummary::printSummary(raw_ostream &OS) {
 253   OS << "Total functions: " << NumFunctions << "\n";
 254   OS << "Maximum function count: " << MaxFunctionCount << "\n";
 255   OS << "Maximum block count: " << MaxCount << "\n";
 256   OS << "Total number of blocks: " << NumCounts << "\n";
 257   OS << "Total count: " << TotalCount << "\n";
 258 }
 259
 260 void ProfileSummary::printDetailedSummary(raw_ostream &OS) {
 261   OS << "Detailed summary:\n";
 262   for (const auto &Entry : DetailedSummary) {
 263     OS << Entry.NumCounts << " blocks with count >= " << Entry.MinCount
 264        << " account for "
 265        << format("%0.6g", (float)Entry.Cutoff / Scale * 100)
 266        << " percentage of the total counts.\n";
 267   }
 268 }