diff --git a/clang/include/clang/AST/ASTContext.h b/clang/include/clang/AST/ASTContext.h
index a1d1d1c51cd417..8bce4812f0d482 100644
--- a/clang/include/clang/AST/ASTContext.h
+++ b/clang/include/clang/AST/ASTContext.h
@@ -3203,9 +3203,6 @@ class ASTContext : public RefCountedBase<ASTContext> {
   /// valid feature names.
   ParsedTargetAttr filterFunctionTargetAttrs(const TargetAttr *TD) const;
 
-  std::vector<std::string>
-  filterFunctionTargetVersionAttrs(const TargetVersionAttr *TV) const;
-
   void getFunctionFeatureMap(llvm::StringMap<bool> &FeatureMap,
                              const FunctionDecl *) const;
   void getFunctionFeatureMap(llvm::StringMap<bool> &FeatureMap,
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index bf74e56a14799c..cd76b8aa271dab 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -87,6 +87,7 @@
 #include "llvm/Support/MD5.h"
 #include "llvm/Support/MathExtras.h"
 #include "llvm/Support/raw_ostream.h"
+#include "llvm/TargetParser/AArch64TargetParser.h"
 #include "llvm/TargetParser/Triple.h"
 #include <algorithm>
 #include <cassert>
@@ -13663,17 +13664,20 @@ QualType ASTContext::getCorrespondingSignedFixedPointType(QualType Ty) const {
   }
 }
 
-std::vector<std::string> ASTContext::filterFunctionTargetVersionAttrs(
-    const TargetVersionAttr *TV) const {
-  assert(TV != nullptr);
-  llvm::SmallVector<StringRef, 8> Feats;
-  std::vector<std::string> ResFeats;
-  TV->getFeatures(Feats);
-  for (auto &Feature : Feats)
-    if (Target->validateCpuSupports(Feature.str()))
-      // Use '?' to mark features that came from TargetVersion.
-      ResFeats.push_back("?" + Feature.str());
-  return ResFeats;
+// Given a list of FMV features, return a concatenated list of the
+// corresponding backend features (which may contain duplicates).
+static std::vector<std::string> getFMVBackendFeaturesFor(
+    const llvm::SmallVectorImpl<StringRef> &FMVFeatStrings) {
+  std::vector<std::string> BackendFeats;
+  for (StringRef F : FMVFeatStrings) {
+    if (auto FMVExt = llvm::AArch64::parseArchExtension(F)) {
+      SmallVector<StringRef, 8> Feats;
+      FMVExt->DependentFeatures.split(Feats, ',', -1, false);
+      for (StringRef F : Feats)
+        BackendFeats.push_back(F.str());
+    }
+  }
+  return BackendFeats;
 }
 
 ParsedTargetAttr
@@ -13708,10 +13712,12 @@ void ASTContext::getFunctionFeatureMap(llvm::StringMap<bool> &FeatureMap,
 
     // Make a copy of the features as passed on the command line into the
     // beginning of the additional features from the function to override.
-    ParsedAttr.Features.insert(
-        ParsedAttr.Features.begin(),
-        Target->getTargetOpts().FeaturesAsWritten.begin(),
-        Target->getTargetOpts().FeaturesAsWritten.end());
+    // AArch64 handles command line option features in parseTargetAttr().
+    if (!Target->getTriple().isAArch64())
+      ParsedAttr.Features.insert(
+          ParsedAttr.Features.begin(),
+          Target->getTargetOpts().FeaturesAsWritten.begin(),
+          Target->getTargetOpts().FeaturesAsWritten.end());
 
     if (ParsedAttr.CPU != "" && Target->isValidCPUName(ParsedAttr.CPU))
       TargetCPU = ParsedAttr.CPU;
@@ -13732,32 +13738,31 @@ void ASTContext::getFunctionFeatureMap(llvm::StringMap<bool> &FeatureMap,
                     Target->getTargetOpts().FeaturesAsWritten.end());
     Target->initFeatureMap(FeatureMap, getDiagnostics(), TargetCPU, Features);
   } else if (const auto *TC = FD->getAttr<TargetClonesAttr>()) {
-    std::vector<std::string> Features;
     if (Target->getTriple().isAArch64()) {
-      // TargetClones for AArch64
       llvm::SmallVector<StringRef, 8> Feats;
       TC->getFeatures(Feats, GD.getMultiVersionIndex());
-      for (StringRef Feat : Feats)
-        if (Target->validateCpuSupports(Feat.str()))
-          // Use '?' to mark features that came from AArch64 TargetClones.
-          Features.push_back("?" + Feat.str());
+      std::vector<std::string> Features = getFMVBackendFeaturesFor(Feats);
       Features.insert(Features.begin(),
                       Target->getTargetOpts().FeaturesAsWritten.begin(),
                       Target->getTargetOpts().FeaturesAsWritten.end());
+      Target->initFeatureMap(FeatureMap, getDiagnostics(), TargetCPU, Features);
     } else {
+      std::vector<std::string> Features;
       StringRef VersionStr = TC->getFeatureStr(GD.getMultiVersionIndex());
       if (VersionStr.starts_with("arch="))
         TargetCPU = VersionStr.drop_front(sizeof("arch=") - 1);
       else if (VersionStr != "default")
         Features.push_back((StringRef{"+"} + VersionStr).str());
+      Target->initFeatureMap(FeatureMap, getDiagnostics(), TargetCPU, Features);
     }
-    Target->initFeatureMap(FeatureMap, getDiagnostics(), TargetCPU, Features);
   } else if (const auto *TV = FD->getAttr<TargetVersionAttr>()) {
-    std::vector<std::string> Feats = filterFunctionTargetVersionAttrs(TV);
-    Feats.insert(Feats.begin(),
-                 Target->getTargetOpts().FeaturesAsWritten.begin(),
-                 Target->getTargetOpts().FeaturesAsWritten.end());
-    Target->initFeatureMap(FeatureMap, getDiagnostics(), TargetCPU, Feats);
+    llvm::SmallVector<StringRef, 8> Feats;
+    TV->getFeatures(Feats);
+    std::vector<std::string> Features = getFMVBackendFeaturesFor(Feats);
+    Features.insert(Features.begin(),
+                    Target->getTargetOpts().FeaturesAsWritten.begin(),
+                    Target->getTargetOpts().FeaturesAsWritten.end());
+    Target->initFeatureMap(FeatureMap, getDiagnostics(), TargetCPU, Features);
   } else {
     FeatureMap = Target->getTargetOpts().FeatureMap;
   }
diff --git a/clang/lib/AST/CMakeLists.txt b/clang/lib/AST/CMakeLists.txt
index a5d3dacfc1a84e..0328666d59b1fc 100644
--- a/clang/lib/AST/CMakeLists.txt
+++ b/clang/lib/AST/CMakeLists.txt
@@ -139,4 +139,6 @@ add_clang_library(clangAST
   omp_gen
   ClangDriverOptions
   intrinsics_gen
+  # These generated headers are included transitively.
+  AArch64TargetParserTableGen
   )
diff --git a/clang/lib/Basic/Targets/AArch64.cpp b/clang/lib/Basic/Targets/AArch64.cpp
index 08d13c41a48572..6fba5fff7bcc19 100644
--- a/clang/lib/Basic/Targets/AArch64.cpp
+++ b/clang/lib/Basic/Targets/AArch64.cpp
@@ -1052,57 +1052,18 @@ bool AArch64TargetInfo::handleTargetFeatures(std::vector<std::string> &Features,
   return true;
 }
 
-bool AArch64TargetInfo::initFeatureMap(
-    llvm::StringMap<bool> &Features, DiagnosticsEngine &Diags, StringRef CPU,
-    const std::vector<std::string> &FeaturesVec) const {
-  std::vector<std::string> UpdatedFeaturesVec;
-  // Parse the CPU and add any implied features.
-  std::optional<llvm::AArch64::CpuInfo> CpuInfo = llvm::AArch64::parseCpu(CPU);
-  if (CpuInfo) {
-    auto Exts = CpuInfo->getImpliedExtensions();
-    std::vector<StringRef> CPUFeats;
-    llvm::AArch64::getExtensionFeatures(Exts, CPUFeats);
-    for (auto F : CPUFeats) {
-      assert((F[0] == '+' || F[0] == '-') && "Expected +/- in target feature!");
-      UpdatedFeaturesVec.push_back(F.str());
-    }
-  }
-
-  // Process target and dependent features. This is done in two loops collecting
-  // them into UpdatedFeaturesVec: first to add dependent '+'features, second to
-  // add target '+/-'features that can later disable some of features added on
-  // the first loop. Function Multi Versioning features begin with '?'.
-  for (const auto &Feature : FeaturesVec)
-    if (((Feature[0] == '?' || Feature[0] == '+')) &&
-        AArch64TargetInfo::doesFeatureAffectCodeGen(Feature.substr(1))) {
-      StringRef DepFeatures =
-          AArch64TargetInfo::getFeatureDependencies(Feature.substr(1));
-      SmallVector<StringRef, 1> AttrFeatures;
-      DepFeatures.split(AttrFeatures, ",");
-      for (auto F : AttrFeatures)
-        UpdatedFeaturesVec.push_back(F.str());
-    }
-  for (const auto &Feature : FeaturesVec)
-    if (Feature[0] != '?') {
-      std::string UpdatedFeature = Feature;
-      if (Feature[0] == '+') {
-        std::optional<llvm::AArch64::ExtensionInfo> Extension =
-            llvm::AArch64::parseArchExtension(Feature.substr(1));
-        if (Extension)
-          UpdatedFeature = Extension->Feature.str();
-      }
-      UpdatedFeaturesVec.push_back(UpdatedFeature);
-    }
-
-  return TargetInfo::initFeatureMap(Features, Diags, CPU, UpdatedFeaturesVec);
-}
-
 // Parse AArch64 Target attributes, which are a comma separated list of:
 //  "arch=<arch>" - parsed to features as per -march=..
 //  "cpu=<cpu>" - parsed to features as per -mcpu=.., with CPU set to <cpu>
 //  "tune=<cpu>" - TuneCPU set to <cpu>
 //  "feature", "no-feature" - Add (or remove) feature.
 //  "+feature", "+nofeature" - Add (or remove) feature.
+//
+// A feature may correspond to an Extension (anything with a corresponding
+// AEK_), in which case an ExtensionSet is used to parse it and expand its
+// dependencies. Otherwise the feature is passed through (e.g. +v8.1a,
+// +outline-atomics, -fmv, etc). Features coming from the command line are
+// already parsed, therefore their dependencies do not need expansion.
 ParsedTargetAttr AArch64TargetInfo::parseTargetAttr(StringRef Features) const {
   ParsedTargetAttr Ret;
   if (Features == "default")
@@ -1112,23 +1073,26 @@ ParsedTargetAttr AArch64TargetInfo::parseTargetAttr(StringRef Features) const {
   bool FoundArch = false;
 
   auto SplitAndAddFeatures = [](StringRef FeatString,
-                                std::vector<std::string> &Features) {
+                                std::vector<std::string> &Features,
+                                llvm::AArch64::ExtensionSet &FeatureBits) {
     SmallVector<StringRef, 8> SplitFeatures;
     FeatString.split(SplitFeatures, StringRef("+"), -1, false);
     for (StringRef Feature : SplitFeatures) {
-      StringRef FeatureName = llvm::AArch64::getArchExtFeature(Feature);
-      if (!FeatureName.empty())
-        Features.push_back(FeatureName.str());
+      if (FeatureBits.parseModifier(Feature, /* AllowNoDashForm = */ true))
+        continue;
+      // Pass through features that are not extensions, e.g. +v8.1a,
+      // +outline-atomics, -fmv, etc.
+      if (Feature.starts_with("no"))
+        Features.push_back("-" + Feature.drop_front(2).str());
       else
-        // Pushing the original feature string to give a sema error later on
-        // when they get checked.
-        if (Feature.starts_with("no"))
-          Features.push_back("-" + Feature.drop_front(2).str());
-        else
-          Features.push_back("+" + Feature.str());
+        Features.push_back("+" + Feature.str());
     }
   };
 
+  llvm::AArch64::ExtensionSet FeatureBits;
+  // Reconstruct the bitset from the command line option features.
+  FeatureBits.reconstructFromParsedFeatures(getTargetOpts().FeaturesAsWritten);
+
   for (auto &Feature : AttrFeatures) {
     Feature = Feature.trim();
     if (Feature.starts_with("fpmath="))
@@ -1151,9 +1115,9 @@ ParsedTargetAttr AArch64TargetInfo::parseTargetAttr(StringRef Features) const {
       // Ret.Features.
       if (!AI)
         continue;
-      Ret.Features.push_back(AI->ArchFeature.str());
+      FeatureBits.addArchDefaults(*AI);
       // Add any extra features, after the +
-      SplitAndAddFeatures(Split.second, Ret.Features);
+      SplitAndAddFeatures(Split.second, Ret.Features, FeatureBits);
     } else if (Feature.starts_with("cpu=")) {
       if (!Ret.CPU.empty())
         Ret.Duplicate = "cpu=";
@@ -1163,7 +1127,10 @@ ParsedTargetAttr AArch64TargetInfo::parseTargetAttr(StringRef Features) const {
         std::pair<StringRef, StringRef> Split =
             Feature.split("=").second.trim().split("+");
         Ret.CPU = Split.first;
-        SplitAndAddFeatures(Split.second, Ret.Features);
+        if (auto CpuInfo = llvm::AArch64::parseCpu(Ret.CPU)) {
+          FeatureBits.addCPUDefaults(*CpuInfo);
+          SplitAndAddFeatures(Split.second, Ret.Features, FeatureBits);
+        }
       }
     } else if (Feature.starts_with("tune=")) {
       if (!Ret.Tune.empty())
@@ -1171,25 +1138,19 @@ ParsedTargetAttr AArch64TargetInfo::parseTargetAttr(StringRef Features) const {
       else
         Ret.Tune = Feature.split("=").second.trim();
     } else if (Feature.starts_with("+")) {
-      SplitAndAddFeatures(Feature, Ret.Features);
-    } else if (Feature.starts_with("no-")) {
-      StringRef FeatureName =
-          llvm::AArch64::getArchExtFeature(Feature.split("-").second);
-      if (!FeatureName.empty())
-        Ret.Features.push_back("-" + FeatureName.drop_front(1).str());
-      else
-        Ret.Features.push_back("-" + Feature.split("-").second.str());
+      SplitAndAddFeatures(Feature, Ret.Features, FeatureBits);
     } else {
-      // Try parsing the string to the internal target feature name. If it is
-      // invalid, add the original string (which could already be an internal
-      // name). These should be checked later by isValidFeatureName.
-      StringRef FeatureName = llvm::AArch64::getArchExtFeature(Feature);
-      if (!FeatureName.empty())
-        Ret.Features.push_back(FeatureName.str());
+      if (FeatureBits.parseModifier(Feature, /* AllowNoDashForm = */ true))
+        continue;
+      // Pass through features that are not extensions, e.g. +v8.1a,
+      // +outline-atomics, -fmv, etc.
+      if (Feature.starts_with("no-"))
+        Ret.Features.push_back("-" + Feature.drop_front(3).str());
       else
         Ret.Features.push_back("+" + Feature.str());
     }
   }
+  FeatureBits.toLLVMFeatureList(Ret.Features);
   return Ret;
 }
 
diff --git a/clang/lib/Basic/Targets/AArch64.h b/clang/lib/Basic/Targets/AArch64.h
index 12fb50286f7511..696553ef8038a8 100644
--- a/clang/lib/Basic/Targets/AArch64.h
+++ b/clang/lib/Basic/Targets/AArch64.h
@@ -107,10 +107,6 @@ class LLVM_LIBRARY_VISIBILITY AArch64TargetInfo : public TargetInfo {
   unsigned multiVersionSortPriority(StringRef Name) const override;
   unsigned multiVersionFeatureCost() const override;
 
-  bool
-  initFeatureMap(llvm::StringMap<bool> &Features, DiagnosticsEngine &Diags,
-                 StringRef CPU,
-                 const std::vector<std::string> &FeaturesVec) const override;
   bool useFP16ConversionIntrinsics() const override {
     return false;
   }
diff --git a/clang/test/CodeGen/aarch64-cpu-supports-target.c b/clang/test/CodeGen/aarch64-cpu-supports-target.c
index e023944b24e53a..28187bcf745331 100644
--- a/clang/test/CodeGen/aarch64-cpu-supports-target.c
+++ b/clang/test/CodeGen/aarch64-cpu-supports-target.c
@@ -48,5 +48,5 @@ int test_versions() {
     return code();
 }
 // CHECK: attributes #0 = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" }
-// CHECK: attributes #1 = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+neon" }
-// CHECK: attributes #2 = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+fp-armv8,+fullfp16,+neon,+sve" }
+// CHECK: attributes #1 = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+fp-armv8,+neon" }
+// CHECK: attributes #2 = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+fp-armv8,+fullfp16,+sve" }
diff --git a/clang/test/CodeGen/aarch64-sme-intrinsics/aarch64-sme-attrs.cpp b/clang/test/CodeGen/aarch64-sme-intrinsics/aarch64-sme-attrs.cpp
index af8933d93d6cbb..9885ac45e6a0e0 100644
--- a/clang/test/CodeGen/aarch64-sme-intrinsics/aarch64-sme-attrs.cpp
+++ b/clang/test/CodeGen/aarch64-sme-intrinsics/aarch64-sme-attrs.cpp
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sme \
+// RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sme -target-feature +bf16 \
 // RUN:   -disable-O0-optnone -Werror -emit-llvm -o - %s \
 // RUN: | opt -S -passes=mem2reg \
 // RUN: | opt -S -passes=inline \
diff --git a/clang/test/CodeGen/aarch64-targetattr.c b/clang/test/CodeGen/aarch64-targetattr.c
index 3e7a2092456071..644e6a692c3be9 100644
--- a/clang/test/CodeGen/aarch64-targetattr.c
+++ b/clang/test/CodeGen/aarch64-targetattr.c
@@ -58,58 +58,50 @@ void v1msve() {}
 // CHECK-LABEL: @plussve() #12
 __attribute__((target("+sve")))
 void plussve() {}
-// CHECK-LABEL: @plussveplussve2() #13
+// CHECK-LABEL: @plussveplussve2() #12
 __attribute__((target("+sve+nosve2")))
 void plussveplussve2() {}
-// CHECK-LABEL: @plussveminusnosve2() #13
+// CHECK-LABEL: @plussveminusnosve2() #12
 __attribute__((target("sve,no-sve2")))
 void plussveminusnosve2() {}
-// CHECK-LABEL: @plusfp16() #14
+// CHECK-LABEL: @plusfp16() #13
 __attribute__((target("+fp16")))
 void plusfp16() {}
 
-// CHECK-LABEL: @all() #15
+// CHECK-LABEL: @all() #14
 __attribute__((target("cpu=neoverse-n1,tune=cortex-a710,arch=armv8.6-a+sve2")))
 void all() {}
-// CHECK-LABEL: @allplusbranchprotection() #16
+// CHECK-LABEL: @allplusbranchprotection() #15
 __attribute__((target("cpu=neoverse-n1,tune=cortex-a710,arch=armv8.6-a+sve2,branch-protection=standard")))
 void allplusbranchprotection() {}
 
-// These tests check that the user facing and internal llvm name are both accepted.
-// CHECK-LABEL: @plusnoneon() #17
-__attribute__((target("+noneon")))
-void plusnoneon() {}
-// CHECK-LABEL: @plusnosimd() #17
+// CHECK-LABEL: @plusnosimd() #16
 __attribute__((target("+nosimd")))
 void plusnosimd() {}
-// CHECK-LABEL: @noneon() #17
-__attribute__((target("no-neon")))
-void noneon() {}
-// CHECK-LABEL: @nosimd() #17
+// CHECK-LABEL: @nosimd() #16
 __attribute__((target("no-simd")))
 void nosimd() {}
 
 // This isn't part of the standard interface, but test that -arch features should not apply anything else.
-// CHECK-LABEL: @minusarch() #18
+// CHECK-LABEL: @minusarch() #17
 __attribute__((target("no-v9.3a")))
 void minusarch() {}
 
 // CHECK: attributes #0 = { {{.*}} "target-features"="+crc,+fp-armv8,+lse,+neon,+ras,+rdm,+v8.1a,+v8.2a,+v8a" }
 // CHECK: attributes #1 = { {{.*}} "target-features"="+crc,+fp-armv8,+fullfp16,+lse,+neon,+ras,+rdm,+sve,+v8.1a,+v8.2a,+v8a" }
 // CHECK: attributes #2 = { {{.*}} "target-features"="+crc,+fp-armv8,+fullfp16,+lse,+neon,+ras,+rdm,+sve,+sve2,+v8.1a,+v8.2a,+v8a" }
-// CHECK: attributes #3 = { {{.*}} "target-features"="+bf16,+complxnum,+crc,+dotprod,+fp-armv8,+fullfp16,+i8mm,+jsconv,+lse,+neon,+pauth,+ras,+rcpc,+rdm,+sve,+sve2,+v8.1a,+v8.2a,+v8.3a,+v8.4a,+v8.5a,+v8.6a,+v8a" }
-// CHECK: attributes #4 = { {{.*}} "target-cpu"="cortex-a710" "target-features"="+bf16,+complxnum,+crc,+dotprod,+flagm,+fp-armv8,+fp16fml,+fullfp16,+i8mm,+jsconv,+lse,+mte,+neon,+pauth,+ras,+rcpc,+rdm,+sb,+sve,+sve2,+sve2-bitperm" }
+// CHECK: attributes #3 = { {{.*}} "target-features"="+bf16,+complxnum,+crc,+dotprod,+fp-armv8,+fp16fml,+fullfp16,+i8mm,+jsconv,+lse,+neon,+pauth,+ras,+rcpc,+rdm,+sve,+sve2,+v8.1a,+v8.2a,+v8.3a,+v8.4a,+v8.5a,+v8.6a,+v8a" }
+// CHECK: attributes #4 = { {{.*}} "target-cpu"="cortex-a710" "target-features"="+bf16,+complxnum,+crc,+dotprod,+flagm,+fp-armv8,+fp16fml,+fullfp16,+i8mm,+jsconv,+lse,+mte,+neon,+pauth,+ras,+rcpc,+rdm,+sb,+sve,+sve2,+sve2-bitperm,+v8.1a,+v8.2a,+v8.3a,+v8.4a,+v8.5a,+v8a,+v9a" }
 // CHECK: attributes #5 = { {{.*}} "tune-cpu"="cortex-a710" }
 // CHECK: attributes #6 = { {{.*}} "target-cpu"="generic" }
 // CHECK: attributes #7 = { {{.*}} "tune-cpu"="generic" }
-// CHECK: attributes #8 = { {{.*}} "target-cpu"="neoverse-n1" "target-features"="+aes,+crc,+dotprod,+fp-armv8,+fullfp16,+lse,+neon,+ras,+rcpc,+rdm,+sha2,+spe,+ssbs" "tune-cpu"="cortex-a710" }
-// CHECK: attributes #9 = { {{.*}} "target-features"="+fp-armv8,+fullfp16,+neon,+sve" "tune-cpu"="cortex-a710" }
-// CHECK: attributes #10 = { {{.*}} "target-cpu"="neoverse-v1" "target-features"="+aes,+bf16,+complxnum,+crc,+dotprod,+fp-armv8,+fp16fml,+fullfp16,+i8mm,+jsconv,+lse,+neon,+pauth,+rand,+ras,+rcpc,+rdm,+sha2,+sha3,+sm4,+spe,+ssbs,+sve,+sve2" }
-// CHECK: attributes #11 = { {{.*}} "target-cpu"="neoverse-v1" "target-features"="+aes,+bf16,+complxnum,+crc,+dotprod,+fp-armv8,+fp16fml,+fullfp16,+i8mm,+jsconv,+lse,+neon,+pauth,+rand,+ras,+rcpc,+rdm,+sha2,+sha3,+sm4,+spe,+ssbs,-sve" }
-// CHECK: attributes #12 = { {{.*}} "target-features"="+fp-armv8,+fullfp16,+neon,+sve" }
-// CHECK: attributes #13 = { {{.*}} "target-features"="+fp-armv8,+fullfp16,+neon,+sve,-sve2" }
-// CHECK: attributes #14 = { {{.*}} "target-features"="+fullfp16" }
-// CHECK: attributes #15 = { {{.*}} "target-cpu"="neoverse-n1" "target-features"="+aes,+bf16,+complxnum,+crc,+dotprod,+fp-armv8,+fullfp16,+i8mm,+jsconv,+lse,+neon,+pauth,+ras,+rcpc,+rdm,+sha2,+spe,+ssbs,+sve,+sve2,+v8.1a,+v8.2a,+v8.3a,+v8.4a,+v8.5a,+v8.6a,+v8a" "tune-cpu"="cortex-a710" }
-// CHECK: attributes #16 = { {{.*}} "branch-target-enforcement"="true" "guarded-control-stack"="true" {{.*}} "target-features"="+aes,+bf16,+complxnum,+crc,+dotprod,+fp-armv8,+fullfp16,+i8mm,+jsconv,+lse,+neon,+pauth,+ras,+rcpc,+rdm,+sha2,+spe,+ssbs,+sve,+sve2,+v8.1a,+v8.2a,+v8.3a,+v8.4a,+v8.5a,+v8.6a,+v8a" "tune-cpu"="cortex-a710" }
-// CHECK: attributes #17 = { {{.*}} "target-features"="-neon" }
-// CHECK: attributes #18 = { {{.*}} "target-features"="-v9.3a" }
+// CHECK: attributes #8 = { {{.*}} "target-cpu"="neoverse-n1" "target-features"="+aes,+crc,+dotprod,+fp-armv8,+fullfp16,+lse,+neon,+ras,+rcpc,+rdm,+sha2,+spe,+ssbs,+v8.1a,+v8.2a,+v8a" "tune-cpu"="cortex-a710" }
+// CHECK: attributes #9 = { {{.*}} "target-features"="+fp-armv8,+fullfp16,+sve" "tune-cpu"="cortex-a710" }
+// CHECK: attributes #10 = { {{.*}} "target-cpu"="neoverse-v1" "target-features"="+aes,+bf16,+complxnum,+crc,+dotprod,+fp-armv8,+fp16fml,+fullfp16,+i8mm,+jsconv,+lse,+neon,+pauth,+rand,+ras,+rcpc,+rdm,+sha2,+sha3,+sm4,+spe,+ssbs,+sve,+sve2,+v8.1a,+v8.2a,+v8.3a,+v8.4a,+v8a" }
+// CHECK: attributes #11 = { {{.*}} "target-cpu"="neoverse-v1" "target-features"="+aes,+bf16,+complxnum,+crc,+dotprod,+fp-armv8,+fp16fml,+fullfp16,+i8mm,+jsconv,+lse,+neon,+pauth,+rand,+ras,+rcpc,+rdm,+sha2,+sha3,+sm4,+spe,+ssbs,+v8.1a,+v8.2a,+v8.3a,+v8.4a,+v8a,-sve" }
+// CHECK: attributes #12 = { {{.*}} "target-features"="+fp-armv8,+fullfp16,+sve" }
+// CHECK: attributes #13 = { {{.*}} "target-features"="+fp-armv8,+fullfp16" }
+// CHECK: attributes #14 = { {{.*}} "target-cpu"="neoverse-n1" "target-features"="+aes,+bf16,+complxnum,+crc,+dotprod,+fp-armv8,+fullfp16,+i8mm,+jsconv,+lse,+neon,+pauth,+ras,+rcpc,+rdm,+sha2,+spe,+ssbs,+sve,+sve2,+v8.1a,+v8.2a,+v8.3a,+v8.4a,+v8.5a,+v8.6a,+v8a" "tune-cpu"="cortex-a710" }
+// CHECK: attributes #15 = { {{.*}} "branch-target-enforcement"="true" "guarded-control-stack"="true" {{.*}} "target-features"="+aes,+bf16,+complxnum,+crc,+dotprod,+fp-armv8,+fullfp16,+i8mm,+jsconv,+lse,+neon,+pauth,+ras,+rcpc,+rdm,+sha2,+spe,+ssbs,+sve,+sve2,+v8.1a,+v8.2a,+v8.3a,+v8.4a,+v8.5a,+v8.6a,+v8a" "tune-cpu"="cortex-a710" }
+// CHECK-NOT: attributes #16 = {{.*}} "target-features"
+// CHECK: attributes #17 = { {{.*}} "target-features"="-v9.3a" }
diff --git a/clang/test/CodeGen/attr-target-version.c b/clang/test/CodeGen/attr-target-version.c
index 3597711333d341..75f8734e5aaf37 100644
--- a/clang/test/CodeGen/attr-target-version.c
+++ b/clang/test/CodeGen/attr-target-version.c
@@ -1129,42 +1129,42 @@ int caller(void) { return used_def_without_default_decl() + used_decl_without_de
 // CHECK-NOFMV-NEXT:    ret i32 0
 //
 //.
-// CHECK: attributes #[[ATTR0]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+flagm,+fp16fml,+fullfp16,+neon,+rand,-fp-armv8,-v9.5a" }
+// CHECK: attributes #[[ATTR0]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+flagm,+fp-armv8,+fp16fml,+fullfp16,+neon,+rand,-v9.5a" }
 // CHECK: attributes #[[ATTR1]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+altnzcv,+bf16,+flagm,+sme,+sme-i16i64,-fp-armv8,-v9.5a" }
-// CHECK: attributes #[[ATTR2]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+lse,+neon,+sha2,-fp-armv8,-v9.5a" }
-// CHECK: attributes #[[ATTR3]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+dotprod,+ls64,+neon,-fp-armv8,-v9.5a" }
-// CHECK: attributes #[[ATTR4]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+fp16fml,+fullfp16,+neon,-fp-armv8,-v9.5a" }
-// CHECK: attributes #[[ATTR5]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+neon,-fp-armv8,-v9.5a" }
+// CHECK: attributes #[[ATTR2]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+fp-armv8,+lse,+neon,+sha2,-v9.5a" }
+// CHECK: attributes #[[ATTR3]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+dotprod,+fp-armv8,+ls64,+neon,-v9.5a" }
+// CHECK: attributes #[[ATTR4]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+fp-armv8,+fp16fml,+fullfp16,+neon,-v9.5a" }
+// CHECK: attributes #[[ATTR5]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+fp-armv8,+neon,-v9.5a" }
 // CHECK: attributes #[[ATTR6]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+crc,-fp-armv8,-v9.5a" }
 // CHECK: attributes #[[ATTR7]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+bti,-fp-armv8,-v9.5a" }
 // CHECK: attributes #[[ATTR8]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+bf16,+sme,+sme2,-fp-armv8,-v9.5a" }
 // CHECK: attributes #[[ATTR9:[0-9]+]] = { "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="-fp-armv8,-v9.5a" }
 // CHECK: attributes #[[ATTR10]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+ccpp,-fp-armv8,-v9.5a" }
 // CHECK: attributes #[[ATTR11]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="-fp-armv8,-v9.5a" }
-// CHECK: attributes #[[ATTR12]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+fullfp16,+neon,-fp-armv8,-v9.5a" }
+// CHECK: attributes #[[ATTR12]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+fp-armv8,+fullfp16,+neon,-v9.5a" }
 // CHECK: attributes #[[ATTR13]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+sb,-fp-armv8,-v9.5a" }
 // CHECK: attributes #[[ATTR14]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+mops,-fp-armv8,-v9.5a" }
-// CHECK: attributes #[[ATTR15]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+dotprod,+neon,-fp-armv8,-v9.5a" }
-// CHECK: attributes #[[ATTR16]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+fullfp16,+neon,+sve,-fp-armv8,-v9.5a" }
+// CHECK: attributes #[[ATTR15]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+dotprod,+fp-armv8,+neon,-v9.5a" }
+// CHECK: attributes #[[ATTR16]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+fp-armv8,+fullfp16,+neon,+sve,-v9.5a" }
 // CHECK: attributes #[[ATTR17]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+lse,-fp-armv8,-v9.5a" }
-// CHECK: attributes #[[ATTR18]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+neon,+rdm,-fp-armv8,-v9.5a" }
-// CHECK: attributes #[[ATTR19:[0-9]+]] = { "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+jsconv,+neon,-fp-armv8,-v9.5a" }
-// CHECK: attributes #[[ATTR20:[0-9]+]] = { "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+neon,+rdm,-fp-armv8,-v9.5a" }
-// CHECK: attributes #[[ATTR21]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+jsconv,+neon,-fp-armv8,-v9.5a" }
-// CHECK: attributes #[[ATTR22]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+aes,+f64mm,+fullfp16,+neon,+sve,-fp-armv8,-v9.5a" }
-// CHECK: attributes #[[ATTR23]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+bf16,+complxnum,+fullfp16,+neon,+rdm,+sme,-fp-armv8,-v9.5a" }
-// CHECK: attributes #[[ATTR24]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+f32mm,+fullfp16,+i8mm,+neon,+sha2,+sha3,+sve,-fp-armv8,-v9.5a" }
-// CHECK: attributes #[[ATTR25]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+bf16,+dit,+fullfp16,+neon,+sve,-fp-armv8,-v9.5a" }
+// CHECK: attributes #[[ATTR18]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+fp-armv8,+neon,+rdm,-v9.5a" }
+// CHECK: attributes #[[ATTR19:[0-9]+]] = { "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+fp-armv8,+jsconv,+neon,-v9.5a" }
+// CHECK: attributes #[[ATTR20:[0-9]+]] = { "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+fp-armv8,+neon,+rdm,-v9.5a" }
+// CHECK: attributes #[[ATTR21]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+fp-armv8,+jsconv,+neon,-v9.5a" }
+// CHECK: attributes #[[ATTR22]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+aes,+f64mm,+fp-armv8,+fullfp16,+neon,+sve,-v9.5a" }
+// CHECK: attributes #[[ATTR23]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+bf16,+complxnum,+fp-armv8,+fullfp16,+neon,+rdm,+sme,-v9.5a" }
+// CHECK: attributes #[[ATTR24]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+f32mm,+fp-armv8,+fullfp16,+i8mm,+neon,+sha2,+sha3,+sve,-v9.5a" }
+// CHECK: attributes #[[ATTR25]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+bf16,+dit,+fp-armv8,+fullfp16,+neon,+sve,-v9.5a" }
 // CHECK: attributes #[[ATTR26]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+ccpp,+rcpc,-fp-armv8,-v9.5a" }
-// CHECK: attributes #[[ATTR27]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+ccdp,+ccpp,+jsconv,+neon,-fp-armv8,-v9.5a" }
+// CHECK: attributes #[[ATTR27]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+ccdp,+ccpp,+fp-armv8,+jsconv,+neon,-v9.5a" }
 // CHECK: attributes #[[ATTR28]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+fptoint,+rcpc,-fp-armv8,-v9.5a" }
-// CHECK: attributes #[[ATTR29]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+bf16,+fullfp16,+neon,+sve,-fp-armv8,-v9.5a" }
-// CHECK: attributes #[[ATTR30]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+fullfp16,+neon,+sve,+sve2,+sve2-aes,+sve2-sha3,-fp-armv8,-v9.5a" }
-// CHECK: attributes #[[ATTR31]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+fullfp16,+neon,+sve,+sve2,+sve2-aes,+sve2-bitperm,-fp-armv8,-v9.5a" }
-// CHECK: attributes #[[ATTR32]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+fullfp16,+mte,+neon,+sve,+sve2,+sve2-sm4,-fp-armv8,-v9.5a" }
+// CHECK: attributes #[[ATTR29]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+bf16,+fp-armv8,+fullfp16,+neon,+sve,-v9.5a" }
+// CHECK: attributes #[[ATTR30]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+fp-armv8,+fullfp16,+neon,+sve,+sve2,+sve2-aes,+sve2-sha3,-v9.5a" }
+// CHECK: attributes #[[ATTR31]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+fp-armv8,+fullfp16,+neon,+sve,+sve2,+sve2-aes,+sve2-bitperm,-v9.5a" }
+// CHECK: attributes #[[ATTR32]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+fp-armv8,+fullfp16,+mte,+neon,+sve,+sve2,+sve2-sm4,-v9.5a" }
 // CHECK: attributes #[[ATTR33]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+mops,+mte,+rcpc,+rcpc3,-fp-armv8,-v9.5a" }
-// CHECK: attributes #[[ATTR34]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+neon,+sm4,-fp-armv8,-v9.5a" }
-// CHECK: attributes #[[ATTR35]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+lse,+neon,+rdm,-fp-armv8,-v9.5a" }
+// CHECK: attributes #[[ATTR34]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+fp-armv8,+neon,+sm4,-v9.5a" }
+// CHECK: attributes #[[ATTR35]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+fp-armv8,+lse,+neon,+rdm,-v9.5a" }
 //.
 // CHECK-NOFMV: attributes #[[ATTR0]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="-fmv" }
 // CHECK-NOFMV: attributes #[[ATTR1:[0-9]+]] = { "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="-fmv" }
diff --git a/clang/test/Sema/aarch64-neon-target.c b/clang/test/Sema/aarch64-neon-target.c
index fa45fff1d183d6..642afddd88c154 100644
--- a/clang/test/Sema/aarch64-neon-target.c
+++ b/clang/test/Sema/aarch64-neon-target.c
@@ -69,8 +69,8 @@ void undefined(uint32x2_t v2i32, uint32x4_t v4i32, uint16x8_t v8i16, uint8x16_t
   vrnd_f16(v4f16); // expected-error {{always_inline function 'vrnd_f16' requires target feature 'fullfp16'}}
   vmaxnm_f16(v4f16, v4f16); // expected-error {{always_inline function 'vmaxnm_f16' requires target feature 'fullfp16'}}
   vrndi_f16(v4f16); // expected-error {{always_inline function 'vrndi_f16' requires target feature 'fullfp16'}}
-  // fp16fml
-  vfmlal_low_f16(v2f32, v4f16, v4f16); // expected-error {{always_inline function 'vfmlal_low_f16' requires target feature 'fp16fml'}}
+  // fp16fml depends on fp-armv8
+  vfmlal_low_f16(v2f32, v4f16, v4f16); // expected-error {{always_inline function 'vfmlal_low_f16' requires target feature 'fp-armv8'}}
   // i8mm
   vmmlaq_s32(v4i32, v8i16, v8i16); // expected-error {{always_inline function 'vmmlaq_s32' requires target feature 'i8mm'}}
   vusdot_laneq_s32(v2i32, v8i8, v8i16, 0); // expected-error {{always_inline function 'vusdot_s32' requires target feature 'i8mm'}}
diff --git a/llvm/include/llvm/TargetParser/AArch64TargetParser.h b/llvm/include/llvm/TargetParser/AArch64TargetParser.h
index b7c1216d16e5ea..dcb00f6b0249fb 100644
--- a/llvm/include/llvm/TargetParser/AArch64TargetParser.h
+++ b/llvm/include/llvm/TargetParser/AArch64TargetParser.h
@@ -132,48 +132,6 @@ struct ExtensionInfo {
 #define EMIT_EXTENSIONS
 #include "llvm/TargetParser/AArch64TargetParserDef.inc"
 
-struct ExtensionSet {
-  // Set of extensions which are currently enabled.
-  ExtensionBitset Enabled;
-  // Set of extensions which have been enabled or disabled at any point. Used
-  // to avoid cluttering the cc1 command-line with lots of unneeded features.
-  ExtensionBitset Touched;
-  // Base architecture version, which we need to know because some feature
-  // dependencies change depending on this.
-  const ArchInfo *BaseArch;
-
-  ExtensionSet() : Enabled(), Touched(), BaseArch(nullptr) {}
-
-  // Enable the given architecture extension, and any other extensions it
-  // depends on. Does not change the base architecture, or follow dependencies
-  // between features which are only related by required arcitecture versions.
-  void enable(ArchExtKind E);
-
-  // Disable the given architecture extension, and any other extensions which
-  // depend on it. Does not change the base architecture, or follow
-  // dependencies between features which are only related by required
-  // arcitecture versions.
-  void disable(ArchExtKind E);
-
-  // Add default extensions for the given CPU. Records the base architecture,
-  // to later resolve dependencies which depend on it.
-  void addCPUDefaults(const CpuInfo &CPU);
-
-  // Add default extensions for the given architecture version. Records the
-  // base architecture, to later resolve dependencies which depend on it.
-  void addArchDefaults(const ArchInfo &Arch);
-
-  // Add or remove a feature based on a modifier string. The string must be of
-  // the form "<name>" to enable a feature or "no<name>" to disable it. This
-  // will also enable or disable any features as required by the dependencies
-  // between them.
-  bool parseModifier(StringRef Modifier);
-
-  // Convert the set of enabled extension to an LLVM feature list, appending
-  // them to Features.
-  void toLLVMFeatureList(std::vector<StringRef> &Features) const;
-};
-
 // Represents a dependency between two architecture extensions. Later is the
 // feature which was added to the architecture after Earlier, and expands the
 // functionality provided by it. If Later is enabled, then Earlier will also be
@@ -584,6 +542,65 @@ inline constexpr CpuInfo CpuInfos[] = {
                                 AArch64::AEK_PROFILE}))},
 };
 
+struct ExtensionSet {
+  // Set of extensions which are currently enabled.
+  ExtensionBitset Enabled;
+  // Set of extensions which have been enabled or disabled at any point. Used
+  // to avoid cluttering the cc1 command-line with lots of unneeded features.
+  ExtensionBitset Touched;
+  // Base architecture version, which we need to know because some feature
+  // dependencies change depending on this.
+  const ArchInfo *BaseArch;
+
+  ExtensionSet() : Enabled(), Touched(), BaseArch(nullptr) {}
+
+  // Enable the given architecture extension, and any other extensions it
+  // depends on. Does not change the base architecture, or follow dependencies
+  // between features which are only related by required arcitecture versions.
+  void enable(ArchExtKind E);
+
+  // Disable the given architecture extension, and any other extensions which
+  // depend on it. Does not change the base architecture, or follow
+  // dependencies between features which are only related by required
+  // arcitecture versions.
+  void disable(ArchExtKind E);
+
+  // Add default extensions for the given CPU. Records the base architecture,
+  // to later resolve dependencies which depend on it.
+  void addCPUDefaults(const CpuInfo &CPU);
+
+  // Add default extensions for the given architecture version. Records the
+  // base architecture, to later resolve dependencies which depend on it.
+  void addArchDefaults(const ArchInfo &Arch);
+
+  // Add or remove a feature based on a modifier string. The string must be of
+  // the form "<name>" to enable a feature or "no<name>" to disable it. This
+  // will also enable or disable any features as required by the dependencies
+  // between them.
+  bool parseModifier(StringRef Modifier, const bool AllowNoDashForm = false);
+
+  // Constructs a new ExtensionSet by toggling the corresponding bits for every
+  // feature in the \p Features list without expanding their dependencies. Used
+  // for reconstructing an ExtensionSet from the output of toLLVMFeatures().
+  void reconstructFromParsedFeatures(const std::vector<std::string> &Features);
+
+  // Convert the set of enabled extension to an LLVM feature list, appending
+  // them to Features.
+  template <typename T> void toLLVMFeatureList(std::vector<T> &Features) const {
+    if (BaseArch && !BaseArch->ArchFeature.empty())
+      Features.emplace_back(T(BaseArch->ArchFeature));
+
+    for (const auto &E : Extensions) {
+      if (E.Feature.empty() || !Touched.test(E.ID))
+        continue;
+      if (Enabled.test(E.ID))
+        Features.emplace_back(T(E.Feature));
+      else
+        Features.emplace_back(T(E.NegFeature));
+    }
+  }
+};
+
 // Name alias.
 struct Alias {
   StringRef AltName;
@@ -607,7 +624,13 @@ const ArchInfo *getArchForCpu(StringRef CPU);
 
 // Parser
 const ArchInfo *parseArch(StringRef Arch);
+
+// Return the extension which has the given -target-feature name.
+std::optional<ExtensionInfo> targetFeatureToExtension(StringRef TargetFeature);
+
+// Parse a name as defined by the Extension class in tablegen.
 std::optional<ExtensionInfo> parseArchExtension(StringRef Extension);
+
 // Given the name of a CPU or alias, return the correponding CpuInfo.
 std::optional<CpuInfo> parseCpu(StringRef Name);
 // Used by target parser tests
diff --git a/llvm/lib/TargetParser/AArch64TargetParser.cpp b/llvm/lib/TargetParser/AArch64TargetParser.cpp
index ca356ec82bf1f9..d1cc306790522d 100644
--- a/llvm/lib/TargetParser/AArch64TargetParser.cpp
+++ b/llvm/lib/TargetParser/AArch64TargetParser.cpp
@@ -122,6 +122,14 @@ AArch64::parseArchExtension(StringRef ArchExt) {
   return {};
 }
 
+std::optional<AArch64::ExtensionInfo>
+AArch64::targetFeatureToExtension(StringRef TargetFeature) {
+  for (const auto &E : Extensions)
+    if (TargetFeature == E.Feature)
+      return E;
+  return {};
+}
+
 std::optional<AArch64::CpuInfo> AArch64::parseCpu(StringRef Name) {
   // Resolve aliases first.
   Name = resolveCPUAlias(Name);
@@ -213,21 +221,6 @@ void AArch64::ExtensionSet::disable(ArchExtKind E) {
       disable(Dep.Later);
 }
 
-void AArch64::ExtensionSet::toLLVMFeatureList(
-    std::vector<StringRef> &Features) const {
-  if (BaseArch && !BaseArch->ArchFeature.empty())
-    Features.push_back(BaseArch->ArchFeature);
-
-  for (const auto &E : Extensions) {
-    if (E.Feature.empty() || !Touched.test(E.ID))
-      continue;
-    if (Enabled.test(E.ID))
-      Features.push_back(E.Feature);
-    else
-      Features.push_back(E.NegFeature);
-  }
-}
-
 void AArch64::ExtensionSet::addCPUDefaults(const CpuInfo &CPU) {
   LLVM_DEBUG(llvm::dbgs() << "addCPUDefaults(" << CPU.Name << ")\n");
   BaseArch = &CPU.Arch;
@@ -247,11 +240,18 @@ void AArch64::ExtensionSet::addArchDefaults(const ArchInfo &Arch) {
       enable(E.ID);
 }
 
-bool AArch64::ExtensionSet::parseModifier(StringRef Modifier) {
+bool AArch64::ExtensionSet::parseModifier(StringRef Modifier,
+                                          const bool AllowNoDashForm) {
   LLVM_DEBUG(llvm::dbgs() << "parseModifier(" << Modifier << ")\n");
 
-  bool IsNegated = Modifier.starts_with("no");
-  StringRef ArchExt = IsNegated ? Modifier.drop_front(2) : Modifier;
+  size_t NChars = 0;
+  // The "no-feat" form is allowed in the target attribute but nowhere else.
+  if (AllowNoDashForm && Modifier.starts_with("no-"))
+    NChars = 3;
+  else if (Modifier.starts_with("no"))
+    NChars = 2;
+  bool IsNegated = NChars != 0;
+  StringRef ArchExt = Modifier.drop_front(NChars);
 
   if (auto AE = parseArchExtension(ArchExt)) {
     if (AE->Feature.empty() || AE->NegFeature.empty())
@@ -265,6 +265,21 @@ bool AArch64::ExtensionSet::parseModifier(StringRef Modifier) {
   return false;
 }
 
+void AArch64::ExtensionSet::reconstructFromParsedFeatures(
+    const std::vector<std::string> &Features) {
+  assert(Touched.none() && "Bitset already initialized");
+  for (auto &F : Features) {
+    bool IsNegated = F[0] == '-';
+    if (auto AE = targetFeatureToExtension(F)) {
+      Touched.set(AE->ID);
+      if (IsNegated)
+        Enabled.reset(AE->ID);
+      else
+        Enabled.set(AE->ID);
+    }
+  }
+}
+
 const AArch64::ExtensionInfo &
 AArch64::getExtensionByID(AArch64::ArchExtKind ExtID) {
   return lookupExtensionByID(ExtID);