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