xref: /openbsd-src/gnu/llvm/llvm/tools/llvm-reduce/deltas/ReduceMetadata.cpp (revision d415bd752c734aee168c4ee86ff32e8cc249eb16)
1 //===- ReduceMetadata.cpp - Specialized Delta Pass ------------------------===//
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 implements two functions used by the Generic Delta Debugging
10 // Algorithm, which are used to reduce Metadata nodes.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "ReduceMetadata.h"
15 #include "Delta.h"
16 #include "llvm/ADT/Sequence.h"
17 #include "llvm/ADT/SmallVector.h"
18 #include "llvm/IR/InstIterator.h"
19 #include "llvm/IR/IntrinsicInst.h"
20 #include <vector>
21 
22 using namespace llvm;
23 
shouldKeepDebugIntrinsicMetadata(Instruction & I,MDNode & MD)24 static bool shouldKeepDebugIntrinsicMetadata(Instruction &I, MDNode &MD) {
25   return isa<DILocation>(MD) && isa<DbgInfoIntrinsic>(I);
26 }
27 
shouldKeepDebugNamedMetadata(NamedMDNode & MD)28 static bool shouldKeepDebugNamedMetadata(NamedMDNode &MD) {
29   return MD.getName() == "llvm.dbg.cu" && MD.getNumOperands() != 0;
30 }
31 
32 // Named metadata with simple list-like behavior, so that it's valid to remove
33 // operands individually.
34 static constexpr StringLiteral ListNamedMetadata[] = {
35   "llvm.module.flags",
36   "llvm.ident",
37   "opencl.spir.version",
38   "opencl.ocl.version",
39   "opencl.used.extensions",
40   "opencl.used.optional.core.features",
41   "opencl.compiler.options"
42 };
43 
44 /// Remove unneeded arguments to named metadata.
reduceNamedMetadataOperands(Oracle & O,ReducerWorkItem & WorkItem)45 static void reduceNamedMetadataOperands(Oracle &O, ReducerWorkItem &WorkItem) {
46   Module &M = WorkItem.getModule();
47 
48   for (StringRef MDName : ListNamedMetadata) {
49     NamedMDNode *NamedNode = M.getNamedMetadata(MDName);
50     if (!NamedNode)
51       continue;
52 
53     bool MadeChange = false;
54     SmallVector<MDNode *, 16> KeptOperands;
55     for (auto I : seq<unsigned>(0, NamedNode->getNumOperands())) {
56       if (O.shouldKeep())
57         KeptOperands.push_back(NamedNode->getOperand(I));
58       else
59         MadeChange = true;
60     }
61 
62     if (MadeChange) {
63       NamedNode->clearOperands();
64       for (MDNode *KeptOperand : KeptOperands)
65         NamedNode->addOperand(KeptOperand);
66     }
67   }
68 }
69 
70 /// Removes all the Named and Unnamed Metadata Nodes, as well as any debug
71 /// functions that aren't inside the desired Chunks.
extractMetadataFromModule(Oracle & O,ReducerWorkItem & WorkItem)72 static void extractMetadataFromModule(Oracle &O, ReducerWorkItem &WorkItem) {
73   Module &Program = WorkItem.getModule();
74 
75   // Get out-of-chunk Named metadata nodes
76   SmallVector<NamedMDNode *> NamedNodesToDelete;
77   for (NamedMDNode &MD : Program.named_metadata())
78     if (!shouldKeepDebugNamedMetadata(MD) && !O.shouldKeep())
79       NamedNodesToDelete.push_back(&MD);
80 
81   for (NamedMDNode *NN : NamedNodesToDelete) {
82     for (auto I : seq<unsigned>(0, NN->getNumOperands()))
83       NN->setOperand(I, nullptr);
84     NN->eraseFromParent();
85   }
86 
87   // Delete out-of-chunk metadata attached to globals.
88   for (GlobalVariable &GV : Program.globals()) {
89     SmallVector<std::pair<unsigned, MDNode *>> MDs;
90     GV.getAllMetadata(MDs);
91     for (std::pair<unsigned, MDNode *> &MD : MDs)
92       if (!O.shouldKeep())
93         GV.setMetadata(MD.first, nullptr);
94   }
95 
96   for (Function &F : Program) {
97     {
98       SmallVector<std::pair<unsigned, MDNode *>> MDs;
99       // Delete out-of-chunk metadata attached to functions.
100       F.getAllMetadata(MDs);
101       for (std::pair<unsigned, MDNode *> &MD : MDs)
102         if (!O.shouldKeep())
103           F.setMetadata(MD.first, nullptr);
104     }
105 
106     // Delete out-of-chunk metadata attached to instructions.
107     for (Instruction &I : instructions(F)) {
108       SmallVector<std::pair<unsigned, MDNode *>> MDs;
109       I.getAllMetadata(MDs);
110       for (std::pair<unsigned, MDNode *> &MD : MDs) {
111         if (!shouldKeepDebugIntrinsicMetadata(I, *MD.second) && !O.shouldKeep())
112           I.setMetadata(MD.first, nullptr);
113       }
114     }
115   }
116 }
117 
reduceMetadataDeltaPass(TestRunner & Test)118 void llvm::reduceMetadataDeltaPass(TestRunner &Test) {
119   runDeltaPass(Test, extractMetadataFromModule, "Reducing Metadata");
120 }
121 
reduceNamedMetadataDeltaPass(TestRunner & Test)122 void llvm::reduceNamedMetadataDeltaPass(TestRunner &Test) {
123   runDeltaPass(Test, reduceNamedMetadataOperands, "Reducing Named Metadata");
124 }
125