diff --git a/tools/llvm-exegesis/lib/AArch64/Target.cpp b/tools/llvm-exegesis/lib/AArch64/Target.cpp
index 90c5927ad29..be8f0b41ede 100644
--- a/tools/llvm-exegesis/lib/AArch64/Target.cpp
+++ b/tools/llvm-exegesis/lib/AArch64/Target.cpp
@@ -11,6 +11,7 @@
 #include "AArch64.h"
 #include "AArch64RegisterInfo.h"
 
+namespace llvm {
 namespace exegesis {
 
 namespace {
@@ -90,3 +91,4 @@ void InitializeAArch64ExegesisTarget() {
 }
 
 } // namespace exegesis
+} // namespace llvm
diff --git a/tools/llvm-exegesis/lib/Analysis.cpp b/tools/llvm-exegesis/lib/Analysis.cpp
index 73c54f53225..0dd6bcbd466 100644
--- a/tools/llvm-exegesis/lib/Analysis.cpp
+++ b/tools/llvm-exegesis/lib/Analysis.cpp
@@ -15,6 +15,7 @@
 #include <unordered_set>
 #include <vector>
 
+namespace llvm {
 namespace exegesis {
 
 static const char kCsvSep = ',';
@@ -796,3 +797,4 @@ std::vector<std::pair<uint16_t, float>> computeIdealizedProcResPressure(
 }
 
 } // namespace exegesis
+} // namespace llvm
diff --git a/tools/llvm-exegesis/lib/Analysis.h b/tools/llvm-exegesis/lib/Analysis.h
index a65a2f1b1da..9ee1493f4e0 100644
--- a/tools/llvm-exegesis/lib/Analysis.h
+++ b/tools/llvm-exegesis/lib/Analysis.h
@@ -30,6 +30,7 @@
 #include <string>
 #include <unordered_map>
 
+namespace llvm {
 namespace exegesis {
 
 // A helper class to analyze benchmark results for a target.
@@ -135,5 +136,6 @@ std::vector<std::pair<uint16_t, float>> computeIdealizedProcResPressure(
     llvm::SmallVector<llvm::MCWriteProcResEntry, 8> WPRS);
 
 } // namespace exegesis
+} // namespace llvm
 
 #endif // LLVM_TOOLS_LLVM_EXEGESIS_CLUSTERING_H
diff --git a/tools/llvm-exegesis/lib/Assembler.cpp b/tools/llvm-exegesis/lib/Assembler.cpp
index 1576cfe58e0..771a6e9ad24 100644
--- a/tools/llvm-exegesis/lib/Assembler.cpp
+++ b/tools/llvm-exegesis/lib/Assembler.cpp
@@ -23,6 +23,7 @@
 #include "llvm/MC/MCInstrInfo.h"
 #include "llvm/Support/MemoryBuffer.h"
 
+namespace llvm {
 namespace exegesis {
 
 static constexpr const char ModuleID[] = "ExegesisInfoTest";
@@ -295,3 +296,4 @@ ExecutableFunction::ExecutableFunction(
 }
 
 } // namespace exegesis
+} // namespace llvm
diff --git a/tools/llvm-exegesis/lib/Assembler.h b/tools/llvm-exegesis/lib/Assembler.h
index f2a77168cb7..ee6bc86f378 100644
--- a/tools/llvm-exegesis/lib/Assembler.h
+++ b/tools/llvm-exegesis/lib/Assembler.h
@@ -32,6 +32,7 @@
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Target/TargetMachine.h"
 
+namespace llvm {
 namespace exegesis {
 
 class ExegesisTarget;
@@ -82,5 +83,6 @@ struct ExecutableFunction {
 };
 
 } // namespace exegesis
+} // namespace llvm
 
 #endif // LLVM_TOOLS_LLVM_EXEGESIS_ASSEMBLER_H
diff --git a/tools/llvm-exegesis/lib/BenchmarkCode.h b/tools/llvm-exegesis/lib/BenchmarkCode.h
index b10dca5c25e..38bea2519a6 100644
--- a/tools/llvm-exegesis/lib/BenchmarkCode.h
+++ b/tools/llvm-exegesis/lib/BenchmarkCode.h
@@ -15,6 +15,7 @@
 #include <string>
 #include <vector>
 
+namespace llvm {
 namespace exegesis {
 
 // A collection of instructions that are to be assembled, executed and measured.
@@ -35,5 +36,6 @@ struct BenchmarkCode {
 };
 
 } // namespace exegesis
+} // namespace llvm
 
 #endif // LLVM_TOOLS_LLVM_EXEGESIS_BENCHMARKCODE_H
diff --git a/tools/llvm-exegesis/lib/BenchmarkResult.cpp b/tools/llvm-exegesis/lib/BenchmarkResult.cpp
index 5d4912ea407..4b91c6c3b3c 100644
--- a/tools/llvm-exegesis/lib/BenchmarkResult.cpp
+++ b/tools/llvm-exegesis/lib/BenchmarkResult.cpp
@@ -22,6 +22,10 @@ static constexpr const char kIntegerPrefix[] = "i_0x";
 static constexpr const char kDoublePrefix[] = "f_";
 static constexpr const char kInvalidOperand[] = "INVALID";
 
+namespace llvm {
+
+namespace {
+
 // A mutable struct holding an LLVMState that can be passed through the
 // serialization process to encode/decode registers and instructions.
 struct YamlContext {
@@ -141,13 +145,13 @@ private:
     return 0;
   }
 
-  const exegesis::LLVMState *State;
+  const llvm::exegesis::LLVMState *State;
   std::string LastError;
   llvm::raw_string_ostream ErrorStream;
 };
+} // namespace
 
 // Defining YAML traits for IO.
-namespace llvm {
 namespace yaml {
 
 static YamlContext &getTypedContext(void *Ctx) {
@@ -294,7 +298,6 @@ struct MappingContextTraits<exegesis::InstructionBenchmark, YamlContext> {
 };
 
 } // namespace yaml
-} // namespace llvm
 
 namespace exegesis {
 
@@ -384,3 +387,4 @@ void PerInstructionStats::push(const BenchmarkMeasure &BM) {
 }
 
 } // namespace exegesis
+} // namespace llvm
diff --git a/tools/llvm-exegesis/lib/BenchmarkResult.h b/tools/llvm-exegesis/lib/BenchmarkResult.h
index 961c07b99dd..773a2e50abc 100644
--- a/tools/llvm-exegesis/lib/BenchmarkResult.h
+++ b/tools/llvm-exegesis/lib/BenchmarkResult.h
@@ -28,6 +28,7 @@
 #include <unordered_map>
 #include <vector>
 
+namespace llvm {
 namespace exegesis {
 
 struct InstructionBenchmarkKey {
@@ -111,5 +112,6 @@ private:
 };
 
 } // namespace exegesis
+} // namespace llvm
 
 #endif // LLVM_TOOLS_LLVM_EXEGESIS_BENCHMARKRESULT_H
diff --git a/tools/llvm-exegesis/lib/BenchmarkRunner.cpp b/tools/llvm-exegesis/lib/BenchmarkRunner.cpp
index 4eb5f1e880c..0d372363927 100644
--- a/tools/llvm-exegesis/lib/BenchmarkRunner.cpp
+++ b/tools/llvm-exegesis/lib/BenchmarkRunner.cpp
@@ -22,6 +22,7 @@
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/Program.h"
 
+namespace llvm {
 namespace exegesis {
 
 BenchmarkFailure::BenchmarkFailure(const llvm::Twine &S)
@@ -173,3 +174,4 @@ BenchmarkRunner::writeObjectFile(const BenchmarkCode &BC,
 BenchmarkRunner::FunctionExecutor::~FunctionExecutor() {}
 
 } // namespace exegesis
+} // namespace llvm
diff --git a/tools/llvm-exegesis/lib/BenchmarkRunner.h b/tools/llvm-exegesis/lib/BenchmarkRunner.h
index 517155dbdfb..4f77f492ab4 100644
--- a/tools/llvm-exegesis/lib/BenchmarkRunner.h
+++ b/tools/llvm-exegesis/lib/BenchmarkRunner.h
@@ -27,6 +27,7 @@
 #include <memory>
 #include <vector>
 
+namespace llvm {
 namespace exegesis {
 
 // A class representing failures that happened during Benchmark, they are used
@@ -90,5 +91,6 @@ private:
 };
 
 } // namespace exegesis
+} // namespace llvm
 
 #endif // LLVM_TOOLS_LLVM_EXEGESIS_BENCHMARKRUNNER_H
diff --git a/tools/llvm-exegesis/lib/Clustering.cpp b/tools/llvm-exegesis/lib/Clustering.cpp
index b63afec945f..761629167bb 100644
--- a/tools/llvm-exegesis/lib/Clustering.cpp
+++ b/tools/llvm-exegesis/lib/Clustering.cpp
@@ -11,6 +11,7 @@
 #include <string>
 #include <unordered_set>
 
+namespace llvm {
 namespace exegesis {
 
 // The clustering problem has the following characteristics:
@@ -170,3 +171,4 @@ InstructionBenchmarkClustering::create(
 }
 
 } // namespace exegesis
+} // namespace llvm
diff --git a/tools/llvm-exegesis/lib/Clustering.h b/tools/llvm-exegesis/lib/Clustering.h
index c811020e0fe..9dc0adffb1e 100644
--- a/tools/llvm-exegesis/lib/Clustering.h
+++ b/tools/llvm-exegesis/lib/Clustering.h
@@ -19,6 +19,7 @@
 #include "llvm/Support/Error.h"
 #include <vector>
 
+namespace llvm {
 namespace exegesis {
 
 class InstructionBenchmarkClustering {
@@ -109,5 +110,6 @@ private:
 };
 
 } // namespace exegesis
+} // namespace llvm
 
 #endif // LLVM_TOOLS_LLVM_EXEGESIS_CLUSTERING_H
diff --git a/tools/llvm-exegesis/lib/CodeTemplate.cpp b/tools/llvm-exegesis/lib/CodeTemplate.cpp
index 614d4749b1f..e159b000755 100644
--- a/tools/llvm-exegesis/lib/CodeTemplate.cpp
+++ b/tools/llvm-exegesis/lib/CodeTemplate.cpp
@@ -9,6 +9,7 @@
 
 #include "CodeTemplate.h"
 
+namespace llvm {
 namespace exegesis {
 
 CodeTemplate::CodeTemplate(CodeTemplate &&) = default;
@@ -115,3 +116,4 @@ getExecutionModeBits(ExecutionMode Execution) {
 }
 
 } // namespace exegesis
+} // namespace llvm
diff --git a/tools/llvm-exegesis/lib/CodeTemplate.h b/tools/llvm-exegesis/lib/CodeTemplate.h
index 734992f0afa..4c55487f3d1 100644
--- a/tools/llvm-exegesis/lib/CodeTemplate.h
+++ b/tools/llvm-exegesis/lib/CodeTemplate.h
@@ -19,6 +19,7 @@
 #include "MCInstrDescView.h"
 #include "llvm/ADT/BitmaskEnum.h"
 
+namespace llvm {
 namespace exegesis {
 
 // A template for an Instruction holding values for each of its Variables.
@@ -125,5 +126,6 @@ struct CodeTemplate {
 };
 
 } // namespace exegesis
+} // namespace llvm
 
 #endif // LLVM_TOOLS_LLVM_EXEGESIS_CODETEMPLATE_H
diff --git a/tools/llvm-exegesis/lib/Latency.cpp b/tools/llvm-exegesis/lib/Latency.cpp
index 7d68d60c48b..ec92d936de3 100644
--- a/tools/llvm-exegesis/lib/Latency.cpp
+++ b/tools/llvm-exegesis/lib/Latency.cpp
@@ -17,6 +17,7 @@
 #include "llvm/MC/MCInstBuilder.h"
 #include "llvm/Support/FormatVariadic.h"
 
+namespace llvm {
 namespace exegesis {
 
 struct ExecutionClass {
@@ -200,3 +201,4 @@ LatencyBenchmarkRunner::runMeasurements(
 }
 
 } // namespace exegesis
+} // namespace llvm
diff --git a/tools/llvm-exegesis/lib/Latency.h b/tools/llvm-exegesis/lib/Latency.h
index cb55f340a5a..fef72cde5a6 100644
--- a/tools/llvm-exegesis/lib/Latency.h
+++ b/tools/llvm-exegesis/lib/Latency.h
@@ -19,6 +19,7 @@
 #include "MCInstrDescView.h"
 #include "SnippetGenerator.h"
 
+namespace llvm {
 namespace exegesis {
 
 class LatencySnippetGenerator : public SnippetGenerator {
@@ -43,5 +44,6 @@ private:
   virtual const char *getCounterName() const;
 };
 } // namespace exegesis
+} // namespace llvm
 
 #endif // LLVM_TOOLS_LLVM_EXEGESIS_LATENCY_H
diff --git a/tools/llvm-exegesis/lib/LlvmState.cpp b/tools/llvm-exegesis/lib/LlvmState.cpp
index 279792e9031..ba786cc97ce 100644
--- a/tools/llvm-exegesis/lib/LlvmState.cpp
+++ b/tools/llvm-exegesis/lib/LlvmState.cpp
@@ -19,6 +19,7 @@
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/Target/TargetOptions.h"
 
+namespace llvm {
 namespace exegesis {
 
 LLVMState::LLVMState(const std::string &Triple, const std::string &CpuName) {
@@ -71,3 +72,4 @@ bool LLVMState::canAssemble(const llvm::MCInst &Inst) const {
 }
 
 } // namespace exegesis
+} // namespace llvm
diff --git a/tools/llvm-exegesis/lib/LlvmState.h b/tools/llvm-exegesis/lib/LlvmState.h
index aa7705a36a6..f8ef8665f44 100644
--- a/tools/llvm-exegesis/lib/LlvmState.h
+++ b/tools/llvm-exegesis/lib/LlvmState.h
@@ -25,6 +25,7 @@
 #include <memory>
 #include <string>
 
+namespace llvm {
 namespace exegesis {
 
 class ExegesisTarget;
@@ -64,5 +65,6 @@ private:
 };
 
 } // namespace exegesis
+} // namespace llvm
 
 #endif // LLVM_TOOLS_LLVM_EXEGESIS_LLVMSTATE_H
diff --git a/tools/llvm-exegesis/lib/MCInstrDescView.cpp b/tools/llvm-exegesis/lib/MCInstrDescView.cpp
index 6fdb5a68419..2b4624b9b64 100644
--- a/tools/llvm-exegesis/lib/MCInstrDescView.cpp
+++ b/tools/llvm-exegesis/lib/MCInstrDescView.cpp
@@ -15,6 +15,7 @@
 
 #include "llvm/ADT/STLExtras.h"
 
+namespace llvm {
 namespace exegesis {
 
 unsigned Variable::getIndex() const {
@@ -343,3 +344,4 @@ void DumpMCInst(const llvm::MCRegisterInfo &MCRegisterInfo,
 }
 
 } // namespace exegesis
+} // namespace llvm
diff --git a/tools/llvm-exegesis/lib/MCInstrDescView.h b/tools/llvm-exegesis/lib/MCInstrDescView.h
index 17f3e2b930d..4e8278ba2b5 100644
--- a/tools/llvm-exegesis/lib/MCInstrDescView.h
+++ b/tools/llvm-exegesis/lib/MCInstrDescView.h
@@ -29,6 +29,7 @@
 #include "llvm/MC/MCInstrDesc.h"
 #include "llvm/MC/MCInstrInfo.h"
 
+namespace llvm {
 namespace exegesis {
 
 // A variable represents the value associated to an Operand or a set of Operands
@@ -191,5 +192,6 @@ void DumpMCInst(const llvm::MCRegisterInfo &MCRegisterInfo,
                 const llvm::MCInst &MCInst, llvm::raw_ostream &OS);
 
 } // namespace exegesis
+} // namespace llvm
 
 #endif // LLVM_TOOLS_LLVM_EXEGESIS_MCINSTRDESCVIEW_H
diff --git a/tools/llvm-exegesis/lib/PerfHelper.cpp b/tools/llvm-exegesis/lib/PerfHelper.cpp
index c145ea8404b..c1c242ca88f 100644
--- a/tools/llvm-exegesis/lib/PerfHelper.cpp
+++ b/tools/llvm-exegesis/lib/PerfHelper.cpp
@@ -17,6 +17,7 @@
 #endif
 #include <cassert>
 
+namespace llvm {
 namespace exegesis {
 namespace pfm {
 
@@ -136,3 +137,4 @@ int64_t Counter::read() const { return 42; }
 
 } // namespace pfm
 } // namespace exegesis
+} // namespace llvm
diff --git a/tools/llvm-exegesis/lib/PerfHelper.h b/tools/llvm-exegesis/lib/PerfHelper.h
index 8c3f13e6c5c..2d081084660 100644
--- a/tools/llvm-exegesis/lib/PerfHelper.h
+++ b/tools/llvm-exegesis/lib/PerfHelper.h
@@ -23,6 +23,7 @@
 
 struct perf_event_attr;
 
+namespace llvm {
 namespace exegesis {
 namespace pfm {
 
@@ -102,5 +103,6 @@ void Measure(
 
 } // namespace pfm
 } // namespace exegesis
+} // namespace llvm
 
 #endif // LLVM_TOOLS_LLVM_EXEGESIS_PERFHELPER_H
diff --git a/tools/llvm-exegesis/lib/RegisterAliasing.cpp b/tools/llvm-exegesis/lib/RegisterAliasing.cpp
index 039f78db985..54041ca30aa 100644
--- a/tools/llvm-exegesis/lib/RegisterAliasing.cpp
+++ b/tools/llvm-exegesis/lib/RegisterAliasing.cpp
@@ -9,6 +9,7 @@
 
 #include "RegisterAliasing.h"
 
+namespace llvm {
 namespace exegesis {
 
 llvm::BitVector getAliasedBits(const llvm::MCRegisterInfo &RegInfo,
@@ -81,3 +82,4 @@ RegisterAliasingTrackerCache::getRegisterClass(unsigned RegClassIndex) const {
 }
 
 } // namespace exegesis
+} // namespace llvm
diff --git a/tools/llvm-exegesis/lib/RegisterAliasing.h b/tools/llvm-exegesis/lib/RegisterAliasing.h
index 064d9333beb..94a2eb07f49 100644
--- a/tools/llvm-exegesis/lib/RegisterAliasing.h
+++ b/tools/llvm-exegesis/lib/RegisterAliasing.h
@@ -22,6 +22,7 @@
 #include "llvm/ADT/PackedVector.h"
 #include "llvm/MC/MCRegisterInfo.h"
 
+namespace llvm {
 namespace exegesis {
 
 // Returns the registers that are aliased by the ones set in SourceBits.
@@ -104,5 +105,6 @@ private:
 };
 
 } // namespace exegesis
+} // namespace llvm
 
 #endif // LLVM_TOOLS_LLVM_EXEGESIS_ALIASINGTRACKER_H
diff --git a/tools/llvm-exegesis/lib/RegisterValue.cpp b/tools/llvm-exegesis/lib/RegisterValue.cpp
index 1982a6c53b2..2bf996cead4 100644
--- a/tools/llvm-exegesis/lib/RegisterValue.cpp
+++ b/tools/llvm-exegesis/lib/RegisterValue.cpp
@@ -10,6 +10,7 @@
 #include "RegisterValue.h"
 #include "llvm/ADT/APFloat.h"
 
+namespace llvm {
 namespace exegesis {
 
 static llvm::APFloat getFloatValue(const llvm::fltSemantics &FltSemantics,
@@ -47,3 +48,4 @@ llvm::APInt bitcastFloatValue(const llvm::fltSemantics &FltSemantics,
 }
 
 } // namespace exegesis
+} // namespace llvm
diff --git a/tools/llvm-exegesis/lib/RegisterValue.h b/tools/llvm-exegesis/lib/RegisterValue.h
index a4ef8e0ba1e..51ea30ac8eb 100644
--- a/tools/llvm-exegesis/lib/RegisterValue.h
+++ b/tools/llvm-exegesis/lib/RegisterValue.h
@@ -17,6 +17,7 @@
 #include <llvm/ADT/APFloat.h>
 #include <llvm/ADT/APInt.h>
 
+namespace llvm {
 namespace exegesis {
 
 // A simple object storing the value for a particular register.
@@ -43,3 +44,4 @@ llvm::APInt bitcastFloatValue(const llvm::fltSemantics &FltSemantics,
                               PredefinedValues Value);
 
 } // namespace exegesis
+} // namespace llvm
diff --git a/tools/llvm-exegesis/lib/SnippetGenerator.cpp b/tools/llvm-exegesis/lib/SnippetGenerator.cpp
index cdf54a32e4f..eb6a8577b57 100644
--- a/tools/llvm-exegesis/lib/SnippetGenerator.cpp
+++ b/tools/llvm-exegesis/lib/SnippetGenerator.cpp
@@ -20,6 +20,7 @@
 #include "llvm/Support/FormatVariadic.h"
 #include "llvm/Support/Program.h"
 
+namespace llvm {
 namespace exegesis {
 
 std::vector<CodeTemplate> getSingleton(CodeTemplate &&CT) {
@@ -222,3 +223,4 @@ void randomizeUnsetVariables(const llvm::BitVector &ForbiddenRegs,
 }
 
 } // namespace exegesis
+} // namespace llvm
diff --git a/tools/llvm-exegesis/lib/SnippetGenerator.h b/tools/llvm-exegesis/lib/SnippetGenerator.h
index 4b307fd75ac..967b273182b 100644
--- a/tools/llvm-exegesis/lib/SnippetGenerator.h
+++ b/tools/llvm-exegesis/lib/SnippetGenerator.h
@@ -28,6 +28,7 @@
 #include <memory>
 #include <vector>
 
+namespace llvm {
 namespace exegesis {
 
 std::vector<CodeTemplate> getSingleton(CodeTemplate &&CT);
@@ -92,5 +93,6 @@ void randomizeUnsetVariables(const llvm::BitVector &ForbiddenRegs,
                              InstructionTemplate &IT);
 
 } // namespace exegesis
+} // namespace llvm
 
 #endif // LLVM_TOOLS_LLVM_EXEGESIS_SNIPPETGENERATOR_H
diff --git a/tools/llvm-exegesis/lib/Target.cpp b/tools/llvm-exegesis/lib/Target.cpp
index 8baa8499c92..b7828a13da0 100644
--- a/tools/llvm-exegesis/lib/Target.cpp
+++ b/tools/llvm-exegesis/lib/Target.cpp
@@ -11,6 +11,7 @@
 #include "Latency.h"
 #include "Uops.h"
 
+namespace llvm {
 namespace exegesis {
 
 ExegesisTarget::~ExegesisTarget() {} // anchor.
@@ -109,3 +110,4 @@ const ExegesisTarget &ExegesisTarget::getDefault() {
 }
 
 } // namespace exegesis
+} // namespace llvm
diff --git a/tools/llvm-exegesis/lib/Target.h b/tools/llvm-exegesis/lib/Target.h
index dd778d35b72..2e94727d78d 100644
--- a/tools/llvm-exegesis/lib/Target.h
+++ b/tools/llvm-exegesis/lib/Target.h
@@ -28,6 +28,7 @@
 #include "llvm/MC/MCInst.h"
 #include "llvm/MC/MCRegisterInfo.h"
 
+namespace llvm {
 namespace exegesis {
 
 class ExegesisTarget {
@@ -100,5 +101,6 @@ private:
 };
 
 } // namespace exegesis
+} // namespace llvm
 
 #endif // LLVM_TOOLS_LLVM_EXEGESIS_TARGET_H
diff --git a/tools/llvm-exegesis/lib/Uops.cpp b/tools/llvm-exegesis/lib/Uops.cpp
index 50be707feb2..5aa726218c7 100644
--- a/tools/llvm-exegesis/lib/Uops.cpp
+++ b/tools/llvm-exegesis/lib/Uops.cpp
@@ -78,6 +78,7 @@
 // In that case we just use a greedy register assignment and hope for the
 // best.
 
+namespace llvm {
 namespace exegesis {
 
 static llvm::SmallVector<const Variable *, 8>
@@ -252,3 +253,4 @@ UopsBenchmarkRunner::runMeasurements(const FunctionExecutor &Executor) const {
 constexpr const size_t UopsSnippetGenerator::kMinNumDifferentAddresses;
 
 } // namespace exegesis
+} // namespace llvm
diff --git a/tools/llvm-exegesis/lib/Uops.h b/tools/llvm-exegesis/lib/Uops.h
index f75f2edd552..b2a5ea177f4 100644
--- a/tools/llvm-exegesis/lib/Uops.h
+++ b/tools/llvm-exegesis/lib/Uops.h
@@ -18,6 +18,7 @@
 #include "BenchmarkRunner.h"
 #include "SnippetGenerator.h"
 
+namespace llvm {
 namespace exegesis {
 
 class UopsSnippetGenerator : public SnippetGenerator {
@@ -73,5 +74,6 @@ private:
 };
 
 } // namespace exegesis
+} // namespace llvm
 
 #endif // LLVM_TOOLS_LLVM_EXEGESIS_UOPS_H
diff --git a/tools/llvm-exegesis/lib/X86/Target.cpp b/tools/llvm-exegesis/lib/X86/Target.cpp
index db1a23b74cc..69804849e62 100644
--- a/tools/llvm-exegesis/lib/X86/Target.cpp
+++ b/tools/llvm-exegesis/lib/X86/Target.cpp
@@ -17,6 +17,7 @@
 #include "X86Subtarget.h"
 #include "llvm/MC/MCInstBuilder.h"
 
+namespace llvm {
 namespace exegesis {
 
 namespace {
@@ -423,3 +424,4 @@ void InitializeX86ExegesisTarget() {
 }
 
 } // namespace exegesis
+} // namespace llvm
diff --git a/tools/llvm-exegesis/llvm-exegesis.cpp b/tools/llvm-exegesis/llvm-exegesis.cpp
index bbc1c9ba28c..ea991420039 100644
--- a/tools/llvm-exegesis/llvm-exegesis.cpp
+++ b/tools/llvm-exegesis/llvm-exegesis.cpp
@@ -38,63 +38,63 @@
 #include <algorithm>
 #include <string>
 
-static llvm::cl::opt<int>
-    OpcodeIndex("opcode-index", llvm::cl::desc("opcode to measure, by index"),
-                llvm::cl::init(0));
-
-static llvm::cl::opt<std::string> OpcodeNames(
-    "opcode-name",
-    llvm::cl::desc("comma-separated list of opcodes to measure, by name"),
-    llvm::cl::init(""));
-
-static llvm::cl::opt<std::string>
-    SnippetsFile("snippets-file", llvm::cl::desc("code snippets to measure"),
-                 llvm::cl::init(""));
-
-static llvm::cl::opt<std::string>
-    BenchmarkFile("benchmarks-file", llvm::cl::desc(""), llvm::cl::init(""));
-
-static llvm::cl::opt<exegesis::InstructionBenchmark::ModeE> BenchmarkMode(
-    "mode", llvm::cl::desc("the mode to run"),
-    llvm::cl::values(clEnumValN(exegesis::InstructionBenchmark::Latency,
-                                "latency", "Instruction Latency"),
-                     clEnumValN(exegesis::InstructionBenchmark::Uops, "uops",
-                                "Uop Decomposition"),
-                     // When not asking for a specific benchmark mode, we'll
-                     // analyse the results.
-                     clEnumValN(exegesis::InstructionBenchmark::Unknown,
-                                "analysis", "Analysis")));
-
-static llvm::cl::opt<unsigned>
-    NumRepetitions("num-repetitions",
-                   llvm::cl::desc("number of time to repeat the asm snippet"),
-                   llvm::cl::init(10000));
-
-static llvm::cl::opt<bool> IgnoreInvalidSchedClass(
-    "ignore-invalid-sched-class",
-    llvm::cl::desc("ignore instructions that do not define a sched class"),
-    llvm::cl::init(false));
-
-static llvm::cl::opt<unsigned> AnalysisNumPoints(
-    "analysis-numpoints",
-    llvm::cl::desc("minimum number of points in an analysis cluster"),
-    llvm::cl::init(3));
-
-static llvm::cl::opt<float>
-    AnalysisEpsilon("analysis-epsilon",
-                    llvm::cl::desc("dbscan epsilon for analysis clustering"),
-                    llvm::cl::init(0.1));
-
-static llvm::cl::opt<std::string>
-    AnalysisClustersOutputFile("analysis-clusters-output-file",
-                               llvm::cl::desc(""), llvm::cl::init("-"));
-static llvm::cl::opt<std::string>
-    AnalysisInconsistenciesOutputFile("analysis-inconsistencies-output-file",
-                                      llvm::cl::desc(""), llvm::cl::init("-"));
-
+namespace llvm {
 namespace exegesis {
 
-static llvm::ExitOnError ExitOnErr;
+static cl::opt<int> OpcodeIndex("opcode-index",
+                                cl::desc("opcode to measure, by index"),
+                                cl::init(0));
+
+static cl::opt<std::string>
+    OpcodeNames("opcode-name",
+                cl::desc("comma-separated list of opcodes to measure, by name"),
+                cl::init(""));
+
+static cl::opt<std::string> SnippetsFile("snippets-file",
+                                         cl::desc("code snippets to measure"),
+                                         cl::init(""));
+
+static cl::opt<std::string> BenchmarkFile("benchmarks-file", cl::desc(""),
+                                          cl::init(""));
+
+static cl::opt<exegesis::InstructionBenchmark::ModeE>
+    BenchmarkMode("mode", cl::desc("the mode to run"),
+                  cl::values(clEnumValN(exegesis::InstructionBenchmark::Latency,
+                                        "latency", "Instruction Latency"),
+                             clEnumValN(exegesis::InstructionBenchmark::Uops,
+                                        "uops", "Uop Decomposition"),
+                             // When not asking for a specific benchmark mode,
+                             // we'll analyse the results.
+                             clEnumValN(exegesis::InstructionBenchmark::Unknown,
+                                        "analysis", "Analysis")));
+
+static cl::opt<unsigned>
+    NumRepetitions("num-repetitions",
+                   cl::desc("number of time to repeat the asm snippet"),
+                   cl::init(10000));
+
+static cl::opt<bool> IgnoreInvalidSchedClass(
+    "ignore-invalid-sched-class",
+    cl::desc("ignore instructions that do not define a sched class"),
+    cl::init(false));
+
+static cl::opt<unsigned> AnalysisNumPoints(
+    "analysis-numpoints",
+    cl::desc("minimum number of points in an analysis cluster"), cl::init(3));
+
+static cl::opt<float>
+    AnalysisEpsilon("analysis-epsilon",
+                    cl::desc("dbscan epsilon for analysis clustering"),
+                    cl::init(0.1));
+
+static cl::opt<std::string>
+    AnalysisClustersOutputFile("analysis-clusters-output-file", cl::desc(""),
+                               cl::init("-"));
+static cl::opt<std::string>
+    AnalysisInconsistenciesOutputFile("analysis-inconsistencies-output-file",
+                                      cl::desc(""), cl::init("-"));
+
+static ExitOnError ExitOnErr;
 
 #ifdef LLVM_EXEGESIS_INITIALIZE_NATIVE_TARGET
 void LLVM_EXEGESIS_INITIALIZE_NATIVE_TARGET();
@@ -430,9 +430,11 @@ static void analysisMain() {
 }
 
 } // namespace exegesis
+} // namespace llvm
 
 int main(int Argc, char **Argv) {
-  llvm::cl::ParseCommandLineOptions(Argc, Argv, "");
+  using namespace llvm;
+  cl::ParseCommandLineOptions(Argc, Argv, "");
 
   exegesis::ExitOnErr.setExitCodeMapper([](const llvm::Error &Err) {
     if (Err.isA<llvm::StringError>())
@@ -440,7 +442,7 @@ int main(int Argc, char **Argv) {
     return EXIT_FAILURE;
   });
 
-  if (BenchmarkMode == exegesis::InstructionBenchmark::Unknown) {
+  if (exegesis::BenchmarkMode == exegesis::InstructionBenchmark::Unknown) {
     exegesis::analysisMain();
   } else {
     exegesis::benchmarkMain();
diff --git a/unittests/tools/llvm-exegesis/AArch64/TargetTest.cpp b/unittests/tools/llvm-exegesis/AArch64/TargetTest.cpp
index 1f394ae2efd..8a519bb2e7b 100644
--- a/unittests/tools/llvm-exegesis/AArch64/TargetTest.cpp
+++ b/unittests/tools/llvm-exegesis/AArch64/TargetTest.cpp
@@ -9,6 +9,7 @@
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
 
+namespace llvm {
 namespace exegesis {
 
 void InitializeAArch64ExegesisTarget();
@@ -60,3 +61,4 @@ TEST_F(AArch64TargetTest, SetRegToConstant) {
 
 } // namespace
 } // namespace exegesis
+} // namespace llvm
diff --git a/unittests/tools/llvm-exegesis/ARM/AssemblerTest.cpp b/unittests/tools/llvm-exegesis/ARM/AssemblerTest.cpp
index db8b9dfc3b7..a20fa5556bb 100644
--- a/unittests/tools/llvm-exegesis/ARM/AssemblerTest.cpp
+++ b/unittests/tools/llvm-exegesis/ARM/AssemblerTest.cpp
@@ -10,6 +10,7 @@
 #include "../Common/AssemblerUtils.h"
 #include "ARMInstrInfo.h"
 
+namespace llvm {
 namespace exegesis {
 namespace {
 
@@ -47,3 +48,4 @@ TEST_F(ARMMachineFunctionGeneratorTest, DISABLED_JitFunctionADDrr) {
 
 } // namespace
 } // namespace exegesis
+} // namespace llvm
diff --git a/unittests/tools/llvm-exegesis/BenchmarkRunnerTest.cpp b/unittests/tools/llvm-exegesis/BenchmarkRunnerTest.cpp
index 05b36a31b9e..c518491063a 100644
--- a/unittests/tools/llvm-exegesis/BenchmarkRunnerTest.cpp
+++ b/unittests/tools/llvm-exegesis/BenchmarkRunnerTest.cpp
@@ -11,6 +11,7 @@
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
 
+namespace llvm {
 namespace exegesis {
 
 namespace {
@@ -29,3 +30,4 @@ TEST(ScratchSpaceTest, Works) {
 
 } // namespace
 } // namespace exegesis
+} // namespace llvm
diff --git a/unittests/tools/llvm-exegesis/ClusteringTest.cpp b/unittests/tools/llvm-exegesis/ClusteringTest.cpp
index e1bffd63454..8ea77dcbdde 100644
--- a/unittests/tools/llvm-exegesis/ClusteringTest.cpp
+++ b/unittests/tools/llvm-exegesis/ClusteringTest.cpp
@@ -14,6 +14,7 @@
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
 
+namespace llvm {
 namespace exegesis {
 
 namespace {
@@ -104,3 +105,4 @@ TEST(ClusteringTest, Ordering) {
 
 } // namespace
 } // namespace exegesis
+} // namespace llvm
diff --git a/unittests/tools/llvm-exegesis/Common/AssemblerUtils.h b/unittests/tools/llvm-exegesis/Common/AssemblerUtils.h
index cc00cee58e3..8a144e5c26f 100644
--- a/unittests/tools/llvm-exegesis/Common/AssemblerUtils.h
+++ b/unittests/tools/llvm-exegesis/Common/AssemblerUtils.h
@@ -24,6 +24,7 @@
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
 
+namespace llvm {
 namespace exegesis {
 
 class MachineFunctionGeneratorBaseTest : public ::testing::Test {
@@ -89,5 +90,6 @@ private:
 };
 
 } // namespace exegesis
+} // namespace llvm
 
 #endif
diff --git a/unittests/tools/llvm-exegesis/PerfHelperTest.cpp b/unittests/tools/llvm-exegesis/PerfHelperTest.cpp
index a8205f9e3eb..91ed4a60967 100644
--- a/unittests/tools/llvm-exegesis/PerfHelperTest.cpp
+++ b/unittests/tools/llvm-exegesis/PerfHelperTest.cpp
@@ -12,6 +12,7 @@
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
 
+namespace llvm {
 namespace exegesis {
 namespace pfm {
 namespace {
@@ -45,3 +46,4 @@ TEST(PerfHelperTest, FunctionalTest) {
 } // namespace
 } // namespace pfm
 } // namespace exegesis
+} // namespace llvm
diff --git a/unittests/tools/llvm-exegesis/RegisterValueTest.cpp b/unittests/tools/llvm-exegesis/RegisterValueTest.cpp
index 4ade990382d..8453720dc70 100644
--- a/unittests/tools/llvm-exegesis/RegisterValueTest.cpp
+++ b/unittests/tools/llvm-exegesis/RegisterValueTest.cpp
@@ -11,6 +11,7 @@
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
 
+namespace llvm {
 namespace exegesis {
 
 namespace {
@@ -69,3 +70,4 @@ TEST(RegisterValueTest, Double) {
 
 } // namespace
 } // namespace exegesis
+} // namespace llvm
diff --git a/unittests/tools/llvm-exegesis/X86/AnalysisTest.cpp b/unittests/tools/llvm-exegesis/X86/AnalysisTest.cpp
index d2d4c152d79..00ac6290aed 100644
--- a/unittests/tools/llvm-exegesis/X86/AnalysisTest.cpp
+++ b/unittests/tools/llvm-exegesis/X86/AnalysisTest.cpp
@@ -8,6 +8,7 @@
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
 
+namespace llvm {
 namespace exegesis {
 namespace {
 
@@ -100,3 +101,4 @@ TEST_F(AnalysisTest, ComputeIdealizedProcResPressure_1P1_1P05_2P0156) {
 
 } // namespace
 } // namespace exegesis
+} // namespace llvm
diff --git a/unittests/tools/llvm-exegesis/X86/AssemblerTest.cpp b/unittests/tools/llvm-exegesis/X86/AssemblerTest.cpp
index 8e81106db8d..451c3f67e75 100644
--- a/unittests/tools/llvm-exegesis/X86/AssemblerTest.cpp
+++ b/unittests/tools/llvm-exegesis/X86/AssemblerTest.cpp
@@ -10,6 +10,7 @@
 #include "../Common/AssemblerUtils.h"
 #include "X86InstrInfo.h"
 
+namespace llvm {
 namespace exegesis {
 
 void InitializeX86ExegesisTarget();
@@ -63,3 +64,4 @@ TEST_F(X86MachineFunctionGeneratorTest, DISABLED_JitFunctionMOV32ri) {
 
 } // namespace
 } // namespace exegesis
+} // namespace llvm
diff --git a/unittests/tools/llvm-exegesis/X86/BenchmarkResultTest.cpp b/unittests/tools/llvm-exegesis/X86/BenchmarkResultTest.cpp
index b17ae1caff3..f069c21b364 100644
--- a/unittests/tools/llvm-exegesis/X86/BenchmarkResultTest.cpp
+++ b/unittests/tools/llvm-exegesis/X86/BenchmarkResultTest.cpp
@@ -25,6 +25,7 @@ using ::testing::get;
 using ::testing::Pointwise;
 using ::testing::Property;
 
+namespace llvm {
 namespace exegesis {
 
 bool operator==(const BenchmarkMeasure &A, const BenchmarkMeasure &B) {
@@ -136,3 +137,4 @@ TEST(BenchmarkResultTest, PerInstructionStats) {
 }
 } // namespace
 } // namespace exegesis
+} // namespace llvm
diff --git a/unittests/tools/llvm-exegesis/X86/RegisterAliasingTest.cpp b/unittests/tools/llvm-exegesis/X86/RegisterAliasingTest.cpp
index 12f76541d4d..007b0156b1f 100644
--- a/unittests/tools/llvm-exegesis/X86/RegisterAliasingTest.cpp
+++ b/unittests/tools/llvm-exegesis/X86/RegisterAliasingTest.cpp
@@ -9,6 +9,7 @@
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
 
+namespace llvm {
 namespace exegesis {
 namespace {
 
@@ -89,3 +90,4 @@ TEST_F(RegisterAliasingTest, TrackRegisterClassCache) {
 
 } // namespace
 } // namespace exegesis
+} // namespace llvm
diff --git a/unittests/tools/llvm-exegesis/X86/SnippetGeneratorTest.cpp b/unittests/tools/llvm-exegesis/X86/SnippetGeneratorTest.cpp
index 4b3fa5455a3..04517359d8a 100644
--- a/unittests/tools/llvm-exegesis/X86/SnippetGeneratorTest.cpp
+++ b/unittests/tools/llvm-exegesis/X86/SnippetGeneratorTest.cpp
@@ -17,6 +17,7 @@
 
 #include <unordered_set>
 
+namespace llvm {
 namespace exegesis {
 
 void InitializeX86ExegesisTarget();
@@ -413,3 +414,4 @@ TEST_F(FakeSnippetGeneratorTest, ComputeRegisterInitialValuesAdd64rr) {
 
 } // namespace
 } // namespace exegesis
+} // namespace llvm
diff --git a/unittests/tools/llvm-exegesis/X86/TargetTest.cpp b/unittests/tools/llvm-exegesis/X86/TargetTest.cpp
index 5ada03b2e9e..2d9d7bcd559 100644
--- a/unittests/tools/llvm-exegesis/X86/TargetTest.cpp
+++ b/unittests/tools/llvm-exegesis/X86/TargetTest.cpp
@@ -35,6 +35,7 @@ bool operator==(const MCInst &a, const MCInst &b) {
 
 } // namespace llvm
 
+namespace llvm {
 namespace exegesis {
 
 void InitializeX86ExegesisTarget();
@@ -376,3 +377,4 @@ TEST_F(Core2TargetTest, SetRegToFP1_4Bits) {
 
 } // namespace
 } // namespace exegesis
+} // namespace llvm