1 //===-- ModuleSummaryIndex.cpp - Module Summary Index ---------------------===//
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 implements the module index and summary classes for the
11 // IR library.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "llvm/IR/ModuleSummaryIndex.h"
16 #include "llvm/ADT/StringMap.h"
17 using namespace llvm;
18 
19 // Create the combined module index/summary from multiple
20 // per-module instances.
21 void ModuleSummaryIndex::mergeFrom(std::unique_ptr<ModuleSummaryIndex> Other,
22                                    uint64_t NextModuleId) {
23   if (Other->modulePaths().empty())
24     return;
25 
26   assert(Other->modulePaths().size() == 1 &&
27          "Can only merge from an single-module index at that time");
28 
29   StringRef OtherModPath = Other->modulePaths().begin()->first();
30   StringRef ModPath = addModulePath(OtherModPath, NextModuleId,
31                                     Other->getModuleHash(OtherModPath))
32                           ->first();
33 
34   for (auto &OtherGlobalValSummaryLists : *Other) {
35     GlobalValue::GUID ValueGUID = OtherGlobalValSummaryLists.first;
36     GlobalValueSummaryList &List = OtherGlobalValSummaryLists.second;
37 
38     // Assert that the value summary list only has one entry, since we shouldn't
39     // have duplicate names within a single per-module index.
40     assert(List.size() == 1);
41     std::unique_ptr<GlobalValueSummary> Summary = std::move(List.front());
42 
43     // Note the module path string ref was copied above and is still owned by
44     // the original per-module index. Reset it to the new module path
45     // string reference owned by the combined index.
46     Summary->setModulePath(ModPath);
47 
48     // Add new value summary to existing list. There may be duplicates when
49     // combining GlobalValueMap entries, due to COMDAT values. Any local
50     // values were given unique global IDs.
51     addGlobalValueSummary(ValueGUID, std::move(Summary));
52   }
53 }
54 
55 void ModuleSummaryIndex::removeEmptySummaryEntries() {
56   for (auto MI = begin(), MIE = end(); MI != MIE;) {
57     // Only expect this to be called on a per-module index, which has a single
58     // entry per value entry list.
59     assert(MI->second.size() == 1);
60     if (!MI->second[0])
61       MI = GlobalValueMap.erase(MI);
62     else
63       ++MI;
64   }
65 }
66 
67 // Collect for the given module the list of function it defines
68 // (GUID -> Summary).
69 void ModuleSummaryIndex::collectDefinedFunctionsForModule(
70     StringRef ModulePath, GVSummaryMapTy &GVSummaryMap) const {
71   for (auto &GlobalList : *this) {
72     auto GUID = GlobalList.first;
73     for (auto &GlobSummary : GlobalList.second) {
74       auto *Summary = dyn_cast_or_null<FunctionSummary>(GlobSummary.get());
75       if (!Summary)
76         // Ignore global variable, focus on functions
77         continue;
78       // Ignore summaries from other modules.
79       if (Summary->modulePath() != ModulePath)
80         continue;
81       GVSummaryMap[GUID] = Summary;
82     }
83   }
84 }
85 
86 // Collect for each module the list of function it defines (GUID -> Summary).
87 void ModuleSummaryIndex::collectDefinedGVSummariesPerModule(
88     StringMap<GVSummaryMapTy> &ModuleToDefinedGVSummaries) const {
89   for (auto &GlobalList : *this) {
90     auto GUID = GlobalList.first;
91     for (auto &Summary : GlobalList.second) {
92       ModuleToDefinedGVSummaries[Summary->modulePath()][GUID] = Summary.get();
93     }
94   }
95 }
96 
97 GlobalValueSummary *
98 ModuleSummaryIndex::getGlobalValueSummary(uint64_t ValueGUID,
99                                           bool PerModuleIndex) const {
100   auto SummaryList = findGlobalValueSummaryList(ValueGUID);
101   assert(SummaryList != end() && "GlobalValue not found in index");
102   assert((!PerModuleIndex || SummaryList->second.size() == 1) &&
103          "Expected a single entry per global value in per-module index");
104   auto &Summary = SummaryList->second[0];
105   return Summary.get();
106 }
107