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      1 //=-- Profilesummary.cpp - Profile summary support --------------------------=//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 // This file contains support for converting profile summary data from/to
     11 // metadata.
     12 //
     13 //===----------------------------------------------------------------------===//
     14 
     15 #include "llvm/IR/ProfileSummary.h"
     16 #include "llvm/IR/Attributes.h"
     17 #include "llvm/IR/Constants.h"
     18 #include "llvm/IR/Function.h"
     19 #include "llvm/IR/Metadata.h"
     20 #include "llvm/IR/Type.h"
     21 #include "llvm/Support/Casting.h"
     22 
     23 using namespace llvm;
     24 
     25 const char *ProfileSummary::KindStr[2] = {"InstrProf", "SampleProfile"};
     26 
     27 // Return an MDTuple with two elements. The first element is a string Key and
     28 // the second is a uint64_t Value.
     29 static Metadata *getKeyValMD(LLVMContext &Context, const char *Key,
     30                              uint64_t Val) {
     31   Type *Int64Ty = Type::getInt64Ty(Context);
     32   Metadata *Ops[2] = {MDString::get(Context, Key),
     33                       ConstantAsMetadata::get(ConstantInt::get(Int64Ty, Val))};
     34   return MDTuple::get(Context, Ops);
     35 }
     36 
     37 // Return an MDTuple with two elements. The first element is a string Key and
     38 // the second is a string Value.
     39 static Metadata *getKeyValMD(LLVMContext &Context, const char *Key,
     40                              const char *Val) {
     41   Metadata *Ops[2] = {MDString::get(Context, Key), MDString::get(Context, Val)};
     42   return MDTuple::get(Context, Ops);
     43 }
     44 
     45 // This returns an MDTuple representing the detiled summary. The tuple has two
     46 // elements: a string "DetailedSummary" and an MDTuple representing the value
     47 // of the detailed summary. Each element of this tuple is again an MDTuple whose
     48 // elements are the (Cutoff, MinCount, NumCounts) triplet of the
     49 // DetailedSummaryEntry.
     50 Metadata *ProfileSummary::getDetailedSummaryMD(LLVMContext &Context) {
     51   std::vector<Metadata *> Entries;
     52   Type *Int32Ty = Type::getInt32Ty(Context);
     53   Type *Int64Ty = Type::getInt64Ty(Context);
     54   for (auto &Entry : DetailedSummary) {
     55     Metadata *EntryMD[3] = {
     56         ConstantAsMetadata::get(ConstantInt::get(Int32Ty, Entry.Cutoff)),
     57         ConstantAsMetadata::get(ConstantInt::get(Int64Ty, Entry.MinCount)),
     58         ConstantAsMetadata::get(ConstantInt::get(Int32Ty, Entry.NumCounts))};
     59     Entries.push_back(MDTuple::get(Context, EntryMD));
     60   }
     61   Metadata *Ops[2] = {MDString::get(Context, "DetailedSummary"),
     62                       MDTuple::get(Context, Entries)};
     63   return MDTuple::get(Context, Ops);
     64 }
     65 
     66 // This returns an MDTuple representing this ProfileSummary object. The first
     67 // entry of this tuple is another MDTuple of two elements: a string
     68 // "ProfileFormat" and a string representing the format ("InstrProf" or
     69 // "SampleProfile"). The rest of the elements of the outer MDTuple are specific
     70 // to the kind of profile summary as returned by getFormatSpecificMD.
     71 Metadata *ProfileSummary::getMD(LLVMContext &Context) {
     72   std::vector<Metadata *> Components;
     73   Components.push_back(getKeyValMD(Context, "ProfileFormat", KindStr[PSK]));
     74 
     75   Components.push_back(getKeyValMD(Context, "TotalCount", getTotalCount()));
     76   Components.push_back(getKeyValMD(Context, "MaxCount", getMaxCount()));
     77   Components.push_back(
     78       getKeyValMD(Context, "MaxInternalCount", getMaxInternalCount()));
     79   Components.push_back(
     80       getKeyValMD(Context, "MaxFunctionCount", getMaxFunctionCount()));
     81   Components.push_back(getKeyValMD(Context, "NumCounts", getNumCounts()));
     82   Components.push_back(getKeyValMD(Context, "NumFunctions", getNumFunctions()));
     83   Components.push_back(getDetailedSummaryMD(Context));
     84   return MDTuple::get(Context, Components);
     85 }
     86 
     87 // Parse an MDTuple representing (Key, Val) pair.
     88 static bool getVal(MDTuple *MD, const char *Key, uint64_t &Val) {
     89   if (!MD)
     90     return false;
     91   if (MD->getNumOperands() != 2)
     92     return false;
     93   MDString *KeyMD = dyn_cast<MDString>(MD->getOperand(0));
     94   ConstantAsMetadata *ValMD = dyn_cast<ConstantAsMetadata>(MD->getOperand(1));
     95   if (!KeyMD || !ValMD)
     96     return false;
     97   if (!KeyMD->getString().equals(Key))
     98     return false;
     99   Val = cast<ConstantInt>(ValMD->getValue())->getZExtValue();
    100   return true;
    101 }
    102 
    103 // Check if an MDTuple represents a (Key, Val) pair.
    104 static bool isKeyValuePair(MDTuple *MD, const char *Key, const char *Val) {
    105   if (!MD || MD->getNumOperands() != 2)
    106     return false;
    107   MDString *KeyMD = dyn_cast<MDString>(MD->getOperand(0));
    108   MDString *ValMD = dyn_cast<MDString>(MD->getOperand(1));
    109   if (!KeyMD || !ValMD)
    110     return false;
    111   if (!KeyMD->getString().equals(Key) || !ValMD->getString().equals(Val))
    112     return false;
    113   return true;
    114 }
    115 
    116 // Parse an MDTuple representing detailed summary.
    117 static bool getSummaryFromMD(MDTuple *MD, SummaryEntryVector &Summary) {
    118   if (!MD || MD->getNumOperands() != 2)
    119     return false;
    120   MDString *KeyMD = dyn_cast<MDString>(MD->getOperand(0));
    121   if (!KeyMD || !KeyMD->getString().equals("DetailedSummary"))
    122     return false;
    123   MDTuple *EntriesMD = dyn_cast<MDTuple>(MD->getOperand(1));
    124   if (!EntriesMD)
    125     return false;
    126   for (auto &&MDOp : EntriesMD->operands()) {
    127     MDTuple *EntryMD = dyn_cast<MDTuple>(MDOp);
    128     if (!EntryMD || EntryMD->getNumOperands() != 3)
    129       return false;
    130     ConstantAsMetadata *Op0 =
    131         dyn_cast<ConstantAsMetadata>(EntryMD->getOperand(0));
    132     ConstantAsMetadata *Op1 =
    133         dyn_cast<ConstantAsMetadata>(EntryMD->getOperand(1));
    134     ConstantAsMetadata *Op2 =
    135         dyn_cast<ConstantAsMetadata>(EntryMD->getOperand(2));
    136 
    137     if (!Op0 || !Op1 || !Op2)
    138       return false;
    139     Summary.emplace_back(cast<ConstantInt>(Op0->getValue())->getZExtValue(),
    140                          cast<ConstantInt>(Op1->getValue())->getZExtValue(),
    141                          cast<ConstantInt>(Op2->getValue())->getZExtValue());
    142   }
    143   return true;
    144 }
    145 
    146 ProfileSummary *ProfileSummary::getFromMD(Metadata *MD) {
    147   if (!MD)
    148     return nullptr;
    149   if (!isa<MDTuple>(MD))
    150     return nullptr;
    151   MDTuple *Tuple = cast<MDTuple>(MD);
    152   if (Tuple->getNumOperands() != 8)
    153     return nullptr;
    154 
    155   auto &FormatMD = Tuple->getOperand(0);
    156   ProfileSummary::Kind SummaryKind;
    157   if (isKeyValuePair(dyn_cast_or_null<MDTuple>(FormatMD), "ProfileFormat",
    158                      "SampleProfile"))
    159     SummaryKind = PSK_Sample;
    160   else if (isKeyValuePair(dyn_cast_or_null<MDTuple>(FormatMD), "ProfileFormat",
    161                           "InstrProf"))
    162     SummaryKind = PSK_Instr;
    163   else
    164     return nullptr;
    165 
    166   uint64_t NumCounts, TotalCount, NumFunctions, MaxFunctionCount, MaxCount,
    167       MaxInternalCount;
    168   if (!getVal(dyn_cast<MDTuple>(Tuple->getOperand(1)), "TotalCount",
    169               TotalCount))
    170     return nullptr;
    171   if (!getVal(dyn_cast<MDTuple>(Tuple->getOperand(2)), "MaxCount", MaxCount))
    172     return nullptr;
    173   if (!getVal(dyn_cast<MDTuple>(Tuple->getOperand(3)), "MaxInternalCount",
    174               MaxInternalCount))
    175     return nullptr;
    176   if (!getVal(dyn_cast<MDTuple>(Tuple->getOperand(4)), "MaxFunctionCount",
    177               MaxFunctionCount))
    178     return nullptr;
    179   if (!getVal(dyn_cast<MDTuple>(Tuple->getOperand(5)), "NumCounts", NumCounts))
    180     return nullptr;
    181   if (!getVal(dyn_cast<MDTuple>(Tuple->getOperand(6)), "NumFunctions",
    182               NumFunctions))
    183     return nullptr;
    184 
    185   SummaryEntryVector Summary;
    186   if (!getSummaryFromMD(dyn_cast<MDTuple>(Tuple->getOperand(7)), Summary))
    187     return nullptr;
    188   return new ProfileSummary(SummaryKind, Summary, TotalCount, MaxCount,
    189                             MaxInternalCount, MaxFunctionCount, NumCounts,
    190                             NumFunctions);
    191 }
    192