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().equals(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().equals(Key) || !ValMD->getString().equals(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().equals("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 }
268