[llvm] Remove "const" in the presence of "constexpr" (NFC)

[kazutakahirata]

"const" is extraneous in the presence of "constexpr" for simple
variables and arrays.

[llvmbot]

@llvm/pr-subscribers-backend-amdgpu
@llvm/pr-subscribers-tools-llvm-exegesis
@llvm/pr-subscribers-compiler-rt-sanitizer

@llvm/pr-subscribers-llvm-support

Author: Kazu Hirata (kazutakahirata)

Changes

"const" is extraneous in the presence of "constexpr" for simple
variables and arrays.

---

Patch is 23.45 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/166109.diff

29 Files Affected:

• (modified) llvm/include/llvm/CodeGen/GlobalMergeFunctions.h (+1-1)
• (modified) llvm/include/llvm/SandboxIR/Context.h (+1-1)
• (modified) llvm/include/llvm/SandboxIR/Instruction.h (+1-1)
• (modified) llvm/include/llvm/SandboxIR/PassManager.h (+4-4)
• (modified) llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp (+1-1)
• (modified) llvm/lib/Support/UnicodeNameToCodepoint.cpp (+4-4)
• (modified) llvm/lib/Target/AMDGPU/AMDGPUAttributor.cpp (+1-1)
• (modified) llvm/lib/Target/AMDGPU/SIInstrInfo.cpp (+3-3)
• (modified) llvm/lib/Transforms/IPO/OpenMPOpt.cpp (+3-3)
• (modified) llvm/lib/Transforms/Instrumentation/NumericalStabilitySanitizer.cpp (+1-1)
• (modified) llvm/lib/Transforms/Vectorize/SandboxVectorizer/DependencyGraph.cpp (+1-1)
• (modified) llvm/lib/Transforms/Vectorize/SandboxVectorizer/Passes/BottomUpVec.cpp (+2-2)
• (modified) llvm/lib/Transforms/Vectorize/SandboxVectorizer/SandboxVectorizer.cpp (+1-1)
• (modified) llvm/tools/llvm-exegesis/lib/AArch64/Target.cpp (+1-1)
• (modified) llvm/tools/llvm-exegesis/lib/Analysis.cpp (+1-1)
• (modified) llvm/tools/llvm-exegesis/lib/Assembler.cpp (+2-2)
• (modified) llvm/tools/llvm-exegesis/lib/BenchmarkResult.cpp (+5-5)
• (modified) llvm/tools/llvm-exegesis/lib/BenchmarkRunner.cpp (+1-1)
• (modified) llvm/tools/llvm-exegesis/lib/BenchmarkRunner.h (+2-2)
• (modified) llvm/tools/llvm-exegesis/lib/Clustering.h (+4-4)
• (modified) llvm/tools/llvm-exegesis/lib/SubprocessMemory.h (+2-2)
• (modified) llvm/tools/llvm-exegesis/lib/UopsBenchmarkRunner.h (+1-1)
• (modified) llvm/tools/llvm-exegesis/lib/X86/Target.cpp (+7-7)
• (modified) llvm/unittests/tools/llvm-exegesis/AArch64/TargetTest.cpp (+1-1)
• (modified) llvm/unittests/tools/llvm-exegesis/PowerPC/TargetTest.cpp (+1-1)
• (modified) llvm/unittests/tools/llvm-exegesis/X86/SnippetRepetitorTest.cpp (+2-2)
• (modified) llvm/unittests/tools/llvm-exegesis/X86/SubprocessMemoryTest.cpp (+1-1)
• (modified) llvm/unittests/tools/llvm-exegesis/X86/TargetTest.cpp (+4-4)
• (modified) llvm/unittests/tools/llvm-exegesis/X86/TestBase.h (+1-1)

diff --git a/llvm/include/llvm/CodeGen/GlobalMergeFunctions.h b/llvm/include/llvm/CodeGen/GlobalMergeFunctions.h
index caea5b62851ea..54ea68a418846 100644
--- a/llvm/include/llvm/CodeGen/GlobalMergeFunctions.h
+++ b/llvm/include/llvm/CodeGen/GlobalMergeFunctions.h
@@ -58,7 +58,7 @@ class GlobalMergeFunc {
   /// The suffix used to identify the merged function that parameterizes
   /// the constant values. Note that the original function, without this suffix,
   /// becomes a thunk supplying contexts to the merged function via parameters.
-  static constexpr const char MergingInstanceSuffix[] = ".Tgm";
+  static constexpr char MergingInstanceSuffix[] = ".Tgm";
 
   GlobalMergeFunc(const ModuleSummaryIndex *Index) : Index(Index) {};
 
diff --git a/llvm/include/llvm/SandboxIR/Context.h b/llvm/include/llvm/SandboxIR/Context.h
index 7d8b2c86e94a7..a8966db29ab26 100644
--- a/llvm/include/llvm/SandboxIR/Context.h
+++ b/llvm/include/llvm/SandboxIR/Context.h
@@ -51,7 +51,7 @@ class Context {
     // Uses a 64-bit integer so we don't have to worry about the unlikely case
     // of overflowing a 32-bit counter.
     using ValTy = uint64_t;
-    static constexpr const ValTy InvalidVal = 0;
+    static constexpr ValTy InvalidVal = 0;
 
   private:
     // Default initialization results in an invalid ID.
diff --git a/llvm/include/llvm/SandboxIR/Instruction.h b/llvm/include/llvm/SandboxIR/Instruction.h
index e1c1ca039a8a0..5e369a482be57 100644
--- a/llvm/include/llvm/SandboxIR/Instruction.h
+++ b/llvm/include/llvm/SandboxIR/Instruction.h
@@ -1866,7 +1866,7 @@ class SwitchInst : public SingleLLVMInstructionImpl<llvm::SwitchInst> {
   friend class Context; // For accessing the constructor in create*()
 
 public:
-  static constexpr const unsigned DefaultPseudoIndex =
+  static constexpr unsigned DefaultPseudoIndex =
       llvm::SwitchInst::DefaultPseudoIndex;
 
   LLVM_ABI static SwitchInst *create(Value *V, BasicBlock *Dest,
diff --git a/llvm/include/llvm/SandboxIR/PassManager.h b/llvm/include/llvm/SandboxIR/PassManager.h
index 93ca710805dd4..a8117aa3b9fa8 100644
--- a/llvm/include/llvm/SandboxIR/PassManager.h
+++ b/llvm/include/llvm/SandboxIR/PassManager.h
@@ -59,10 +59,10 @@ class PassManager : public ParentPass {
     Passes.push_back(std::move(Pass));
   }
 
-  static constexpr const char EndToken = '\0';
-  static constexpr const char BeginArgsToken = '<';
-  static constexpr const char EndArgsToken = '>';
-  static constexpr const char PassDelimToken = ',';
+  static constexpr char EndToken = '\0';
+  static constexpr char BeginArgsToken = '<';
+  static constexpr char EndArgsToken = '>';
+  static constexpr char PassDelimToken = ',';
 
   /// Parses \p Pipeline as a comma-separated sequence of pass names and sets
   /// the pass pipeline, using \p CreatePass to instantiate passes by name.
diff --git a/llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp b/llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp
index 0e5926ff0fb18..fff9a815e5368 100644
--- a/llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp
+++ b/llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp
@@ -528,7 +528,7 @@ void OpenMPIRBuilder::getKernelArgsVector(TargetKernelArgs &KernelArgs,
   Value *Version = Builder.getInt32(OMP_KERNEL_ARG_VERSION);
   Value *PointerNum = Builder.getInt32(KernelArgs.NumTargetItems);
   auto Int32Ty = Type::getInt32Ty(Builder.getContext());
-  constexpr const size_t MaxDim = 3;
+  constexpr size_t MaxDim = 3;
   Value *ZeroArray = Constant::getNullValue(ArrayType::get(Int32Ty, MaxDim));
   Value *Flags = Builder.getInt64(KernelArgs.HasNoWait);
 
diff --git a/llvm/lib/Support/UnicodeNameToCodepoint.cpp b/llvm/lib/Support/UnicodeNameToCodepoint.cpp
index 6f8e0915ab632..8f0d24ea1c1c6 100644
--- a/llvm/lib/Support/UnicodeNameToCodepoint.cpp
+++ b/llvm/lib/Support/UnicodeNameToCodepoint.cpp
@@ -251,10 +251,10 @@ constexpr const char *const HangulSyllables[][3] = {
 
 // Unicode 15.0
 // 3.12 Conjoining Jamo Behavior Common constants
-constexpr const char32_t SBase = 0xAC00;
-constexpr const uint32_t LCount = 19;
-constexpr const uint32_t VCount = 21;
-constexpr const uint32_t TCount = 28;
+constexpr char32_t SBase = 0xAC00;
+constexpr uint32_t LCount = 19;
+constexpr uint32_t VCount = 21;
+constexpr uint32_t TCount = 28;
 
 static std::size_t findSyllable(StringRef Name, bool Strict,
                                 char &PreviousInName, int &Pos, int Column) {
diff --git a/llvm/lib/Target/AMDGPU/AMDGPUAttributor.cpp b/llvm/lib/Target/AMDGPU/AMDGPUAttributor.cpp
index 9907c88f4dfb8..8669978637f40 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUAttributor.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUAttributor.cpp
@@ -1555,7 +1555,7 @@ struct AAAMDGPUClusterDimsFunction : public AAAMDGPUClusterDims {
 
   AMDGPU::ClusterDimsAttr Attr;
 
-  static constexpr const char AttrName[] = "amdgpu-cluster-dims";
+  static constexpr char AttrName[] = "amdgpu-cluster-dims";
 };
 
 AAAMDGPUClusterDims &
diff --git a/llvm/lib/Target/AMDGPU/SIInstrInfo.cpp b/llvm/lib/Target/AMDGPU/SIInstrInfo.cpp
index d9f76c9a59d00..45f591927b86e 100644
--- a/llvm/lib/Target/AMDGPU/SIInstrInfo.cpp
+++ b/llvm/lib/Target/AMDGPU/SIInstrInfo.cpp
@@ -6153,7 +6153,7 @@ bool SIInstrInfo::isLegalRegOperand(const MachineInstr &MI, unsigned OpIdx,
   // information.
   if (AMDGPU::isPackedFP32Inst(MI.getOpcode()) && AMDGPU::isGFX12Plus(ST) &&
       MO.isReg() && RI.isSGPRReg(MRI, MO.getReg())) {
-    constexpr const AMDGPU::OpName OpNames[] = {
+    constexpr AMDGPU::OpName OpNames[] = {
         AMDGPU::OpName::src0, AMDGPU::OpName::src1, AMDGPU::OpName::src2};
 
     for (auto [I, OpName] : enumerate(OpNames)) {
@@ -6215,8 +6215,8 @@ bool SIInstrInfo::isLegalVSrcOperand(const MachineRegisterInfo &MRI,
 bool SIInstrInfo::isLegalGFX12PlusPackedMathFP32Operand(
     const MachineRegisterInfo &MRI, const MachineInstr &MI, unsigned SrcN,
     const MachineOperand *MO) const {
-  constexpr const unsigned NumOps = 3;
-  constexpr const AMDGPU::OpName OpNames[NumOps * 2] = {
+  constexpr unsigned NumOps = 3;
+  constexpr AMDGPU::OpName OpNames[NumOps * 2] = {
       AMDGPU::OpName::src0,           AMDGPU::OpName::src1,
       AMDGPU::OpName::src2,           AMDGPU::OpName::src0_modifiers,
       AMDGPU::OpName::src1_modifiers, AMDGPU::OpName::src2_modifiers};
diff --git a/llvm/lib/Transforms/IPO/OpenMPOpt.cpp b/llvm/lib/Transforms/IPO/OpenMPOpt.cpp
index d7eb745c81317..2a87a0f9aaa99 100644
--- a/llvm/lib/Transforms/IPO/OpenMPOpt.cpp
+++ b/llvm/lib/Transforms/IPO/OpenMPOpt.cpp
@@ -208,7 +208,7 @@ namespace KernelInfo {
 // };
 
 #define KERNEL_ENVIRONMENT_IDX(MEMBER, IDX)                                    \
-  constexpr const unsigned MEMBER##Idx = IDX;
+  constexpr unsigned MEMBER##Idx = IDX;
 
 KERNEL_ENVIRONMENT_IDX(Configuration, 0)
 KERNEL_ENVIRONMENT_IDX(Ident, 1)
@@ -216,7 +216,7 @@ KERNEL_ENVIRONMENT_IDX(Ident, 1)
 #undef KERNEL_ENVIRONMENT_IDX
 
 #define KERNEL_ENVIRONMENT_CONFIGURATION_IDX(MEMBER, IDX)                      \
-  constexpr const unsigned MEMBER##Idx = IDX;
+  constexpr unsigned MEMBER##Idx = IDX;
 
 KERNEL_ENVIRONMENT_CONFIGURATION_IDX(UseGenericStateMachine, 0)
 KERNEL_ENVIRONMENT_CONFIGURATION_IDX(MayUseNestedParallelism, 1)
@@ -258,7 +258,7 @@ KERNEL_ENVIRONMENT_CONFIGURATION_GETTER(MaxTeams)
 
 GlobalVariable *
 getKernelEnvironementGVFromKernelInitCB(CallBase *KernelInitCB) {
-  constexpr const int InitKernelEnvironmentArgNo = 0;
+  constexpr int InitKernelEnvironmentArgNo = 0;
   return cast<GlobalVariable>(
       KernelInitCB->getArgOperand(InitKernelEnvironmentArgNo)
           ->stripPointerCasts());
diff --git a/llvm/lib/Transforms/Instrumentation/NumericalStabilitySanitizer.cpp b/llvm/lib/Transforms/Instrumentation/NumericalStabilitySanitizer.cpp
index 80e77e099c695..a2fad021e0480 100644
--- a/llvm/lib/Transforms/Instrumentation/NumericalStabilitySanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/NumericalStabilitySanitizer.cpp
@@ -161,7 +161,7 @@ template <char NsanTypeId>
 class ShadowTypeConfigImpl : public ShadowTypeConfig {
 public:
   char getNsanTypeId() const override { return NsanTypeId; }
-  static constexpr const char kNsanTypeId = NsanTypeId;
+  static constexpr char kNsanTypeId = NsanTypeId;
 };
 
 // `double` (`d`) shadow type.
diff --git a/llvm/lib/Transforms/Vectorize/SandboxVectorizer/DependencyGraph.cpp b/llvm/lib/Transforms/Vectorize/SandboxVectorizer/DependencyGraph.cpp
index 9c869dd1bbdca..d354933f9d4ec 100644
--- a/llvm/lib/Transforms/Vectorize/SandboxVectorizer/DependencyGraph.cpp
+++ b/llvm/lib/Transforms/Vectorize/SandboxVectorizer/DependencyGraph.cpp
@@ -92,7 +92,7 @@ void MemDGNode::print(raw_ostream &OS, bool PrintDeps) const {
   DGNode::print(OS, false);
   if (PrintDeps) {
     // Print memory preds.
-    static constexpr const unsigned Indent = 4;
+    static constexpr unsigned Indent = 4;
     for (auto *Pred : MemPreds)
       OS.indent(Indent) << "<-" << *Pred->getInstruction() << "\n";
   }
diff --git a/llvm/lib/Transforms/Vectorize/SandboxVectorizer/Passes/BottomUpVec.cpp b/llvm/lib/Transforms/Vectorize/SandboxVectorizer/Passes/BottomUpVec.cpp
index 86dbd2171a560..5534da902b968 100644
--- a/llvm/lib/Transforms/Vectorize/SandboxVectorizer/Passes/BottomUpVec.cpp
+++ b/llvm/lib/Transforms/Vectorize/SandboxVectorizer/Passes/BottomUpVec.cpp
@@ -25,14 +25,14 @@ static cl::opt<bool>
                           "emit new instructions (*very* expensive)."));
 #endif // NDEBUG
 
-static constexpr const unsigned long StopAtDisabled =
+static constexpr unsigned long StopAtDisabled =
     std::numeric_limits<unsigned long>::max();
 static cl::opt<unsigned long>
     StopAt("sbvec-stop-at", cl::init(StopAtDisabled), cl::Hidden,
            cl::desc("Vectorize if the invocation count is < than this. 0 "
                     "disables vectorization."));
 
-static constexpr const unsigned long StopBundleDisabled =
+static constexpr unsigned long StopBundleDisabled =
     std::numeric_limits<unsigned long>::max();
 static cl::opt<unsigned long>
     StopBundle("sbvec-stop-bndl", cl::init(StopBundleDisabled), cl::Hidden,
diff --git a/llvm/lib/Transforms/Vectorize/SandboxVectorizer/SandboxVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SandboxVectorizer/SandboxVectorizer.cpp
index ed2f80ba8900a..2de692143c1b6 100644
--- a/llvm/lib/Transforms/Vectorize/SandboxVectorizer/SandboxVectorizer.cpp
+++ b/llvm/lib/Transforms/Vectorize/SandboxVectorizer/SandboxVectorizer.cpp
@@ -43,7 +43,7 @@ cl::opt<std::string> AllowFiles(
     "sbvec-allow-files", cl::init(".*"), cl::Hidden,
     cl::desc("Run the vectorizer only on file paths that match any in the "
              "list of comma-separated regex's."));
-static constexpr const char AllowFilesDelim = ',';
+static constexpr char AllowFilesDelim = ',';
 
 SandboxVectorizerPass::SandboxVectorizerPass() : FPM("fpm") {
   if (UserDefinedPassPipeline == DefaultPipelineMagicStr) {
diff --git a/llvm/tools/llvm-exegesis/lib/AArch64/Target.cpp b/llvm/tools/llvm-exegesis/lib/AArch64/Target.cpp
index 2c13dd514a744..0e73adab15d86 100644
--- a/llvm/tools/llvm-exegesis/lib/AArch64/Target.cpp
+++ b/llvm/tools/llvm-exegesis/lib/AArch64/Target.cpp
@@ -112,7 +112,7 @@ namespace {
 
 // Use X19 as the loop counter register since it's a callee-saved register
 // that's available for temporary use.
-constexpr const MCPhysReg kDefaultLoopCounterReg = AArch64::X19;
+constexpr MCPhysReg kDefaultLoopCounterReg = AArch64::X19;
 
 class ExegesisAArch64Target : public ExegesisTarget {
 public:
diff --git a/llvm/tools/llvm-exegesis/lib/Analysis.cpp b/llvm/tools/llvm-exegesis/lib/Analysis.cpp
index fb843285ada2a..f3bf9690d2a6e 100644
--- a/llvm/tools/llvm-exegesis/lib/Analysis.cpp
+++ b/llvm/tools/llvm-exegesis/lib/Analysis.cpp
@@ -446,7 +446,7 @@ void Analysis::printClusterRawHtml(const BenchmarkClustering::ClusterId &Id,
 
 } // namespace exegesis
 
-static constexpr const char kHtmlHead[] = R"(
+static constexpr char kHtmlHead[] = R"(
 <head>
 <title>llvm-exegesis Analysis Results</title>
 <style>
diff --git a/llvm/tools/llvm-exegesis/lib/Assembler.cpp b/llvm/tools/llvm-exegesis/lib/Assembler.cpp
index fd7924db08441..163f1419b370c 100644
--- a/llvm/tools/llvm-exegesis/lib/Assembler.cpp
+++ b/llvm/tools/llvm-exegesis/lib/Assembler.cpp
@@ -44,8 +44,8 @@
 namespace llvm {
 namespace exegesis {
 
-static constexpr const char ModuleID[] = "ExegesisInfoTest";
-static constexpr const char FunctionID[] = "foo";
+static constexpr char ModuleID[] = "ExegesisInfoTest";
+static constexpr char FunctionID[] = "foo";
 static const Align kFunctionAlignment(4096);
 
 // Fills the given basic block with register setup code, and returns true if
diff --git a/llvm/tools/llvm-exegesis/lib/BenchmarkResult.cpp b/llvm/tools/llvm-exegesis/lib/BenchmarkResult.cpp
index ba14d5639898f..c6164b6323e20 100644
--- a/llvm/tools/llvm-exegesis/lib/BenchmarkResult.cpp
+++ b/llvm/tools/llvm-exegesis/lib/BenchmarkResult.cpp
@@ -21,9 +21,9 @@
 #include "llvm/Support/Format.h"
 #include "llvm/Support/raw_ostream.h"
 
-static constexpr const char kIntegerPrefix[] = "i_0x";
-static constexpr const char kDoublePrefix[] = "f_";
-static constexpr const char kInvalidOperand[] = "INVALID";
+static constexpr char kIntegerPrefix[] = "i_0x";
+static constexpr char kDoublePrefix[] = "f_";
+static constexpr char kInvalidOperand[] = "INVALID";
 
 namespace llvm {
 
@@ -245,8 +245,8 @@ template <> struct SequenceElementTraits<exegesis::RegisterValue> {
 };
 
 template <> struct ScalarTraits<exegesis::RegisterValue> {
-  static constexpr const unsigned kRadix = 16;
-  static constexpr const bool kSigned = false;
+  static constexpr unsigned kRadix = 16;
+  static constexpr bool kSigned = false;
 
   static void output(const exegesis::RegisterValue &RV, void *Ctx,
                      raw_ostream &Out) {
diff --git a/llvm/tools/llvm-exegesis/lib/BenchmarkRunner.cpp b/llvm/tools/llvm-exegesis/lib/BenchmarkRunner.cpp
index 1fd0a15dcfa91..81bf2c9bba7fa 100644
--- a/llvm/tools/llvm-exegesis/lib/BenchmarkRunner.cpp
+++ b/llvm/tools/llvm-exegesis/lib/BenchmarkRunner.cpp
@@ -155,7 +155,7 @@ class InProcessFunctionExecutorImpl : public BenchmarkRunner::FunctionExecutor {
 #ifdef LLVM_ON_UNIX
         // See "Exit Status for Commands":
         // https://pubs.opengroup.org/onlinepubs/9699919799/xrat/V4_xcu_chap02.html
-        constexpr const int kSigOffset = 128;
+        constexpr int kSigOffset = 128;
         return make_error<SnippetSignal>(CRC.RetCode - kSigOffset);
 #else
         // The exit code of the process on windows is not meaningful as a
diff --git a/llvm/tools/llvm-exegesis/lib/BenchmarkRunner.h b/llvm/tools/llvm-exegesis/lib/BenchmarkRunner.h
index e688b814d1c83..16d3c9ccd7658 100644
--- a/llvm/tools/llvm-exegesis/lib/BenchmarkRunner.h
+++ b/llvm/tools/llvm-exegesis/lib/BenchmarkRunner.h
@@ -73,8 +73,8 @@ class BenchmarkRunner {
 
   // Scratch space to run instructions that touch memory.
   struct ScratchSpace {
-    static constexpr const size_t kAlignment = 1024;
-    static constexpr const size_t kSize = 1 << 20; // 1MB.
+    static constexpr size_t kAlignment = 1024;
+    static constexpr size_t kSize = 1 << 20; // 1MB.
     ScratchSpace()
         : UnalignedPtr(std::make_unique<char[]>(kSize + kAlignment)),
           AlignedPtr(
diff --git a/llvm/tools/llvm-exegesis/lib/Clustering.h b/llvm/tools/llvm-exegesis/lib/Clustering.h
index 9d6c110e2e854..2b0f5b4e4a147 100644
--- a/llvm/tools/llvm-exegesis/lib/Clustering.h
+++ b/llvm/tools/llvm-exegesis/lib/Clustering.h
@@ -67,11 +67,11 @@ class BenchmarkClustering {
     ClusterId(size_t Id, bool IsUnstable = false)
         : Id_(Id), IsUnstable_(IsUnstable) {}
 
-    static constexpr const size_t kMaxValid =
+    static constexpr size_t kMaxValid =
         (std::numeric_limits<size_t>::max() >> 1) - 4;
-    static constexpr const size_t kNoise = kMaxValid + 1;
-    static constexpr const size_t kError = kMaxValid + 2;
-    static constexpr const size_t kUndef = kMaxValid + 3;
+    static constexpr size_t kNoise = kMaxValid + 1;
+    static constexpr size_t kError = kMaxValid + 2;
+    static constexpr size_t kUndef = kMaxValid + 3;
 
     size_t Id_ : (std::numeric_limits<size_t>::digits - 1);
     size_t IsUnstable_ : 1;
diff --git a/llvm/tools/llvm-exegesis/lib/SubprocessMemory.h b/llvm/tools/llvm-exegesis/lib/SubprocessMemory.h
index 572d1085d9cff..52ee980b6defd 100644
--- a/llvm/tools/llvm-exegesis/lib/SubprocessMemory.h
+++ b/llvm/tools/llvm-exegesis/lib/SubprocessMemory.h
@@ -32,8 +32,8 @@ namespace exegesis {
 
 class SubprocessMemory {
 public:
-  static constexpr const size_t AuxiliaryMemoryOffset = 1;
-  static constexpr const size_t AuxiliaryMemorySize = 4096;
+  static constexpr size_t AuxiliaryMemoryOffset = 1;
+  static constexpr size_t AuxiliaryMemorySize = 4096;
 
   // Gets the thread ID for the calling thread.
   static long getCurrentTID();
diff --git a/llvm/tools/llvm-exegesis/lib/UopsBenchmarkRunner.h b/llvm/tools/llvm-exegesis/lib/UopsBenchmarkRunner.h
index ef47b7fe8a655..74a18dab80608 100644
--- a/llvm/tools/llvm-exegesis/lib/UopsBenchmarkRunner.h
+++ b/llvm/tools/llvm-exegesis/lib/UopsBenchmarkRunner.h
@@ -30,7 +30,7 @@ class UopsBenchmarkRunner : public BenchmarkRunner {
                         ExecutionMode, ValCounters) {}
   ~UopsBenchmarkRunner() override;
 
-  static constexpr const size_t kMinNumDifferentAddresses = 6;
+  static constexpr size_t kMinNumDifferentAddresses = 6;
 
 private:
   Expected<std::vector<BenchmarkMeasure>>
diff --git a/llvm/tools/llvm-exegesis/lib/X86/Target.cpp b/llvm/tools/llvm-exegesis/lib/X86/Target.cpp
index b4437f798d485..6dc647655d92f 100644
--- a/llvm/tools/llvm-exegesis/lib/X86/Target.cpp
+++ b/llvm/tools/llvm-exegesis/lib/X86/Target.cpp
@@ -278,9 +278,9 @@ static Expected<std::vector<CodeTemplate>> generateLEATemplatesCommon(
   assert(X86II::getMemoryOperandNo(Instr.Description.TSFlags) == 1 &&
          "invalid LEA");
 
-  constexpr const int kDestOp = 0;
-  constexpr const int kBaseOp = 1;
-  constexpr const int kIndexOp = 3;
+  constexpr int kDestOp = 0;
+  constexpr int kBaseOp = 1;
+  constexpr int kIndexOp = 3;
   auto PossibleDestRegs =
       Instr.Operands[kDestOp].getRegisterAliasing().sourceBits();
   remove(PossibleDestRegs, ForbiddenRegisters);
@@ -548,7 +548,7 @@ struct ConstantInliner {
 
   void initStack(unsigned Bytes);
 
-  static constexpr const unsigned kF80Bytes = 10; // 80 bits.
+  static constexpr unsigned kF80Bytes = 10; // 80 bits.
 
   APInt Constant_;
   std::vector<MCInst> Instructions;
@@ -864,7 +864,7 @@ const MCPhysReg ExegesisX86Target::kUnavailableRegistersSSE[12] = {
 // We're using one of R8-R15 because these registers are never hardcoded in
 // instructions (e.g. MOVS writes to EDI, ESI, EDX), so they have less
 // conflicts.
-constexpr const MCPhysReg kDefaultLoopCounterReg = X86::R8;
+constexpr MCPhysReg kDefaultLoopCounterReg = X86::R8;
 
 } // namespace
 
@@ -1110,9 +1110,9 @@ std::vector<MCInst> ExegesisX86Target::setRegTo(const MCSubtargetInfo &STI,
 #ifdef __linux__
 
 #ifdef __arm__
-static constexpr const uintptr_t VAddressSpaceCeiling = 0xC0000000;
+static constexpr uintptr_t VAddressSpaceCeiling = 0xC0000000;
 #else
-static constexpr const uintptr_t VAddressSpaceCeiling = 0x0000800000000000;
+static constexpr uintptr_t VAddressSpaceCeiling = 0x0000800000000000;
 #endif
 
 void generateRoundToNearestPage(unsigned int Register,
diff --git a/llvm/unittests/tools/llvm-exegesis/AArch64/TargetTest.cpp b/llvm/unittests/tools/llvm-exegesis/AArch64/TargetTest.cpp
index 7a66117b7080c..5bc489bd3df65 100644
--- a/llvm/unittests/tools/llvm-exegesis/AArch64/TargetTest.cpp
+++ b/llvm/unittests/tools/llvm-exegesis/AArch64/TargetTest.cpp
@@ -28,7 +28,7 @@ using testing::IsEmpty;
 using testing::Not;
 using testing::NotNull;
 
-constexpr const char kTriple[] = "aarch64-unknown-linux";
+constexpr char kTriple[] = "aarch64-unknown-linux";
 
 class AArch64TargetTest : public ::testing::Test {
 protected:
diff --git a/llvm/unittests/tools/llvm-exegesis/PowerPC/TargetTest.cpp b/llvm/unittests/tools/llvm-exegesis/PowerPC/TargetTest.cpp
index 39c4260f17658..0e90654ab0b4a 100644
--- a/llvm/unittests/tools/llvm-exegesis/PowerPC/TargetTest.cpp
+++ b/llvm/unittests/tools/llvm-exegesis/PowerPC/TargetTest.cpp
@@ -26,7 +26,7 @@ using testing::NotNull;
 using testing::IsEmpty;
 using testing::Not;
 
-constexpr const char kTriple[] = "powerpc64le-unknown-linux";
+constexpr char kTriple[] = "powerpc64le-unknown-linux";
 
 class PowerPCTargetT...
[truncated]

[shiltian]

If my memory serves me correctly, at one point, a pretty famous C++ book recommended writing constexpr const, but I can't remember which one. I also write them as constexpr const.