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   Metadata *Components[] = {
73     getKeyValMD(Context, "ProfileFormat", KindStr[PSK]),
74     getKeyValMD(Context, "TotalCount", getTotalCount()),
75     getKeyValMD(Context, "MaxCount", getMaxCount()),
76     getKeyValMD(Context, "MaxInternalCount", getMaxInternalCount()),
77     getKeyValMD(Context, "MaxFunctionCount", getMaxFunctionCount()),
78     getKeyValMD(Context, "NumCounts", getNumCounts()),
79     getKeyValMD(Context, "NumFunctions", getNumFunctions()),
80     getDetailedSummaryMD(Context),
81   };
82   return MDTuple::get(Context, Components);
83 }
84 
85 // Parse an MDTuple representing (Key, Val) pair.
86 static bool getVal(MDTuple *MD, const char *Key, uint64_t &Val) {
87   if (!MD)
88     return false;
89   if (MD->getNumOperands() != 2)
90     return false;
91   MDString *KeyMD = dyn_cast<MDString>(MD->getOperand(0));
92   ConstantAsMetadata *ValMD = dyn_cast<ConstantAsMetadata>(MD->getOperand(1));
93   if (!KeyMD || !ValMD)
94     return false;
95   if (!KeyMD->getString().equals(Key))
96     return false;
97   Val = cast<ConstantInt>(ValMD->getValue())->getZExtValue();
98   return true;
99 }
100 
101 // Check if an MDTuple represents a (Key, Val) pair.
102 static bool isKeyValuePair(MDTuple *MD, const char *Key, const char *Val) {
103   if (!MD || MD->getNumOperands() != 2)
104     return false;
105   MDString *KeyMD = dyn_cast<MDString>(MD->getOperand(0));
106   MDString *ValMD = dyn_cast<MDString>(MD->getOperand(1));
107   if (!KeyMD || !ValMD)
108     return false;
109   if (!KeyMD->getString().equals(Key) || !ValMD->getString().equals(Val))
110     return false;
111   return true;
112 }
113 
114 // Parse an MDTuple representing detailed summary.
115 static bool getSummaryFromMD(MDTuple *MD, SummaryEntryVector &Summary) {
116   if (!MD || MD->getNumOperands() != 2)
117     return false;
118   MDString *KeyMD = dyn_cast<MDString>(MD->getOperand(0));
119   if (!KeyMD || !KeyMD->getString().equals("DetailedSummary"))
120     return false;
121   MDTuple *EntriesMD = dyn_cast<MDTuple>(MD->getOperand(1));
122   if (!EntriesMD)
123     return false;
124   for (auto &&MDOp : EntriesMD->operands()) {
125     MDTuple *EntryMD = dyn_cast<MDTuple>(MDOp);
126     if (!EntryMD || EntryMD->getNumOperands() != 3)
127       return false;
128     ConstantAsMetadata *Op0 =
129         dyn_cast<ConstantAsMetadata>(EntryMD->getOperand(0));
130     ConstantAsMetadata *Op1 =
131         dyn_cast<ConstantAsMetadata>(EntryMD->getOperand(1));
132     ConstantAsMetadata *Op2 =
133         dyn_cast<ConstantAsMetadata>(EntryMD->getOperand(2));
134 
135     if (!Op0 || !Op1 || !Op2)
136       return false;
137     Summary.emplace_back(cast<ConstantInt>(Op0->getValue())->getZExtValue(),
138                          cast<ConstantInt>(Op1->getValue())->getZExtValue(),
139                          cast<ConstantInt>(Op2->getValue())->getZExtValue());
140   }
141   return true;
142 }
143 
144 ProfileSummary *ProfileSummary::getFromMD(Metadata *MD) {
145   MDTuple *Tuple = dyn_cast_or_null<MDTuple>(MD);
146   if (!Tuple || Tuple->getNumOperands() != 8)
147     return nullptr;
148 
149   auto &FormatMD = Tuple->getOperand(0);
150   ProfileSummary::Kind SummaryKind;
151   if (isKeyValuePair(dyn_cast_or_null<MDTuple>(FormatMD), "ProfileFormat",
152                      "SampleProfile"))
153     SummaryKind = PSK_Sample;
154   else if (isKeyValuePair(dyn_cast_or_null<MDTuple>(FormatMD), "ProfileFormat",
155                           "InstrProf"))
156     SummaryKind = PSK_Instr;
157   else
158     return nullptr;
159 
160   uint64_t NumCounts, TotalCount, NumFunctions, MaxFunctionCount, MaxCount,
161       MaxInternalCount;
162   if (!getVal(dyn_cast<MDTuple>(Tuple->getOperand(1)), "TotalCount",
163               TotalCount))
164     return nullptr;
165   if (!getVal(dyn_cast<MDTuple>(Tuple->getOperand(2)), "MaxCount", MaxCount))
166     return nullptr;
167   if (!getVal(dyn_cast<MDTuple>(Tuple->getOperand(3)), "MaxInternalCount",
168               MaxInternalCount))
169     return nullptr;
170   if (!getVal(dyn_cast<MDTuple>(Tuple->getOperand(4)), "MaxFunctionCount",
171               MaxFunctionCount))
172     return nullptr;
173   if (!getVal(dyn_cast<MDTuple>(Tuple->getOperand(5)), "NumCounts", NumCounts))
174     return nullptr;
175   if (!getVal(dyn_cast<MDTuple>(Tuple->getOperand(6)), "NumFunctions",
176               NumFunctions))
177     return nullptr;
178 
179   SummaryEntryVector Summary;
180   if (!getSummaryFromMD(dyn_cast<MDTuple>(Tuple->getOperand(7)), Summary))
181     return nullptr;
182   return new ProfileSummary(SummaryKind, std::move(Summary), TotalCount,
183                             MaxCount, MaxInternalCount, MaxFunctionCount,
184                             NumCounts, NumFunctions);
185 }
186