diff --git a/include/swift/AST/ASTContext.h b/include/swift/AST/ASTContext.h
index 8e5bf7e71f8c0..f57f390143a12 100644
--- a/include/swift/AST/ASTContext.h
+++ b/include/swift/AST/ASTContext.h
@@ -95,7 +95,6 @@ namespace swift {
   class TypeVariableType;
   class TupleType;
   class FunctionType;
-  class GenericSignatureBuilder;
   class ArchetypeType;
   class Identifier;
   class InheritedNameSet;
@@ -1225,14 +1224,6 @@ class ASTContext final {
   /// Increments \c NumTypoCorrections then checks this against the limit in
   /// the language options.
   bool shouldPerformTypoCorrection();
-  
-private:
-  /// Register the given generic signature builder to be used as the canonical
-  /// generic signature builder for the given signature, if we don't already
-  /// have one.
-  void registerGenericSignatureBuilder(GenericSignature sig,
-                                       GenericSignatureBuilder &&builder);
-  friend class GenericSignatureBuilder;
 
 private:
   friend class IntrinsicInfo;
@@ -1240,11 +1231,6 @@ class ASTContext final {
   llvm::LLVMContext &getIntrinsicScratchContext() const;
 
 public:
-  /// Retrieve or create the stored generic signature builder for the given
-  /// canonical generic signature and module.
-  GenericSignatureBuilder *getOrCreateGenericSignatureBuilder(
-                                                     CanGenericSignature sig);
-
   rewriting::RewriteContext &getRewriteContext();
 
   /// This is a hack to break cycles. Don't introduce new callers of this
diff --git a/include/swift/AST/GenericSignature.h b/include/swift/AST/GenericSignature.h
index a11d5cc66700d..a750c247a7200 100644
--- a/include/swift/AST/GenericSignature.h
+++ b/include/swift/AST/GenericSignature.h
@@ -30,7 +30,6 @@
 
 namespace swift {
 
-class GenericSignatureBuilder;
 class ProtocolConformanceRef;
 class ProtocolType;
 class SubstitutionMap;
@@ -84,7 +83,6 @@ class ConformanceAccessPath {
   ConformanceAccessPath(ArrayRef<Entry> path) : path(path) {}
 
   friend class GenericSignatureImpl;
-  friend class GenericSignatureBuilder;
   friend class rewriting::RequirementMachine;
 
 public:
@@ -338,9 +336,6 @@ class alignas(1 << TypeAlignInBits) GenericSignatureImpl final
   
   ASTContext &getASTContext() const;
 
-  /// Retrieve the generic signature builder for the given generic signature.
-  GenericSignatureBuilder *getGenericSignatureBuilder() const;
-
   /// Retrieve the requirement machine for the given generic signature.
   rewriting::RequirementMachine *getRequirementMachine() const;
 
@@ -385,8 +380,6 @@ class alignas(1 << TypeAlignInBits) GenericSignatureImpl final
   ///
   /// The type parameters must be known to not be concrete within the context.
   bool areSameTypeParameterInContext(Type type1, Type type2) const;
-  bool areSameTypeParameterInContext(Type type1, Type type2,
-                                     GenericSignatureBuilder &builder) const;
 
   /// Determine if \c sig can prove \c requirement, meaning that it can deduce
   /// T: Foo or T == U (etc.) with the information it knows. This includes
@@ -396,8 +389,6 @@ class alignas(1 << TypeAlignInBits) GenericSignatureImpl final
       Requirement requirement, bool allowMissing = false) const;
 
   bool isCanonicalTypeInContext(Type type) const;
-  bool isCanonicalTypeInContext(Type type,
-                                GenericSignatureBuilder &builder) const;
 
   /// Retrieve the conformance access path used to extract the conformance of
   /// interface \c type to the given \c protocol.
diff --git a/include/swift/Basic/LangOptions.h b/include/swift/Basic/LangOptions.h
index 1b15badd14650..1bfed64e7d81e 100644
--- a/include/swift/Basic/LangOptions.h
+++ b/include/swift/Basic/LangOptions.h
@@ -477,10 +477,6 @@ namespace swift {
     ASTVerifierOverrideKind ASTVerifierOverride =
         ASTVerifierOverrideKind::NoOverride;
 
-    /// Whether the new experimental generics implementation is enabled.
-    RequirementMachineMode EnableRequirementMachine =
-        RequirementMachineMode::Enabled;
-
     /// Enables merged associated type support, which might go away.
     bool RequirementMachineMergedAssociatedTypes = true;
 
diff --git a/include/swift/Option/Options.td b/include/swift/Option/Options.td
index a4a80428ac67b..480dcb1fb2369 100644
--- a/include/swift/Option/Options.td
+++ b/include/swift/Option/Options.td
@@ -616,10 +616,6 @@ def no_emit_module_separately:
   Flags<[NoInteractiveOption, HelpHidden]>,
   HelpText<"Force using merge-module as the incremental build mode (new Driver only)">;
 
-def requirement_machine_EQ : Joined<["-"], "requirement-machine=">,
-  Flags<[FrontendOption, ModuleInterfaceOption]>,
-  HelpText<"Control usage of experimental generics implementation: 'on', 'off', or 'verify'">;
-
 def requirement_machine_protocol_signatures_EQ : Joined<["-"], "requirement-machine-protocol-signatures=">,
   Flags<[FrontendOption]>,
   HelpText<"Control usage of experimental protocol requirement signature minimization: 'on', 'off', or 'verify'">;
diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp
index 84982ee54c39a..21bfef2986770 100644
--- a/lib/AST/ASTContext.cpp
+++ b/lib/AST/ASTContext.cpp
@@ -17,7 +17,6 @@
 #include "swift/AST/ASTContext.h"
 #include "ClangTypeConverter.h"
 #include "ForeignRepresentationInfo.h"
-#include "GenericSignatureBuilder.h"
 #include "SubstitutionMapStorage.h"
 #include "swift/AST/ClangModuleLoader.h"
 #include "swift/AST/ConcreteDeclRef.h"
@@ -72,17 +71,9 @@
 using namespace swift;
 
 #define DEBUG_TYPE "ASTContext"
-STATISTIC(NumRegisteredGenericSignatureBuilders,
-          "# of generic signature builders successfully registered");
-STATISTIC(NumRegisteredGenericSignatureBuildersAlready,
-          "# of generic signature builders already registered");
 STATISTIC(NumCollapsedSpecializedProtocolConformances,
           "# of specialized protocol conformances collapsed");
 
-/// Define this to 1 to enable expensive assertions of the
-/// GenericSignatureBuilder.
-#define SWIFT_GSB_EXPENSIVE_ASSERTIONS 0
-
 void ModuleLoader::anchor() {}
 void ClangModuleLoader::anchor() {}
 
@@ -480,10 +471,6 @@ struct ASTContext::Implementation {
 
   llvm::FoldingSet<GenericSignatureImpl> GenericSignatures;
 
-  /// Stored generic signature builders for canonical generic signatures.
-  llvm::DenseMap<GenericSignature, std::unique_ptr<GenericSignatureBuilder>>
-    GenericSignatureBuilders;
-
   /// A cache of information about whether particular nominal types
   /// are representable in a foreign language.
   llvm::DenseMap<NominalTypeDecl *, ForeignRepresentationInfo>
@@ -1938,111 +1925,6 @@ void ASTContext::addLoadedModule(ModuleDecl *M) {
   getImpl().LoadedModules[M->getRealName()] = M;
 }
 
-void ASTContext::registerGenericSignatureBuilder(
-                                       GenericSignature sig,
-                                       GenericSignatureBuilder &&builder) {
-  if (LangOpts.EnableRequirementMachine == RequirementMachineMode::Enabled)
-    return;
-
-  auto canSig = sig.getCanonicalSignature();
-  auto &genericSignatureBuilders = getImpl().GenericSignatureBuilders;
-  auto known = genericSignatureBuilders.find(canSig);
-  if (known != genericSignatureBuilders.end()) {
-    ++NumRegisteredGenericSignatureBuildersAlready;
-    return;
-  }
-
-  ++NumRegisteredGenericSignatureBuilders;
-  genericSignatureBuilders[canSig] =
-    std::make_unique<GenericSignatureBuilder>(std::move(builder));
-}
-
-GenericSignatureBuilder *ASTContext::getOrCreateGenericSignatureBuilder(
-                                                      CanGenericSignature sig) {
-  // We should only create GenericSignatureBuilders if the requirement machine
-  // mode is ::Disabled or ::Verify.
-  assert(LangOpts.EnableRequirementMachine != RequirementMachineMode::Enabled &&
-         "Shouldn't create GenericSignatureBuilder when RequirementMachine "
-         "is enabled");
-
-  // Check whether we already have a generic signature builder for this
-  // signature and module.
-  auto &genericSignatureBuilders = getImpl().GenericSignatureBuilders;
-  auto known = genericSignatureBuilders.find(sig);
-  if (known != genericSignatureBuilders.end())
-    return known->second.get();
-
-  // Create a new generic signature builder with the given signature.
-  auto builder = new GenericSignatureBuilder(*this);
-
-  // Store this generic signature builder (no generic environment yet).
-  genericSignatureBuilders[sig] =
-    std::unique_ptr<GenericSignatureBuilder>(builder);
-
-  builder->addGenericSignature(sig);
-
-#if SWIFT_GSB_EXPENSIVE_ASSERTIONS
-  auto builderSig =
-    builder->computeGenericSignature(/*allowConcreteGenericParams=*/true);
-  if (builderSig.getCanonicalSignature() != sig) {
-    llvm::errs() << "ERROR: generic signature builder is not idempotent.\n";
-    llvm::errs() << "Original generic signature   : ";
-    sig->print(llvm::errs());
-    llvm::errs() << "\nReprocessed generic signature: ";
-    auto reprocessedSig = builderSig.getCanonicalSignature();
-
-    reprocessedSig->print(llvm::errs());
-    llvm::errs() << "\n";
-
-    if (sig.getGenericParams().size() ==
-          reprocessedSig.getGenericParams().size() &&
-        sig.getRequirements().size() ==
-          reprocessedSig.getRequirements().size()) {
-      for (unsigned i : indices(sig.getRequirements())) {
-        auto sigReq = sig.getRequirements()[i];
-        auto reprocessedReq = reprocessedSig.getRequirements()[i];
-        if (sigReq.getKind() != reprocessedReq.getKind()) {
-          llvm::errs() << "Requirement mismatch:\n";
-          llvm::errs() << "  Original: ";
-          sigReq.print(llvm::errs(), PrintOptions());
-          llvm::errs() << "\n  Reprocessed: ";
-          reprocessedReq.print(llvm::errs(), PrintOptions());
-          llvm::errs() << "\n";
-          break;
-        }
-
-        if (!sigReq.getFirstType()->isEqual(reprocessedReq.getFirstType())) {
-          llvm::errs() << "First type mismatch, original is:\n";
-          sigReq.getFirstType().dump(llvm::errs());
-          llvm::errs() << "Reprocessed:\n";
-          reprocessedReq.getFirstType().dump(llvm::errs());
-          llvm::errs() << "\n";
-          break;
-        }
-
-        if (sigReq.getKind() == RequirementKind::SameType &&
-            !sigReq.getSecondType()->isEqual(reprocessedReq.getSecondType())) {
-          llvm::errs() << "Second type mismatch, original is:\n";
-          sigReq.getSecondType().dump(llvm::errs());
-          llvm::errs() << "Reprocessed:\n";
-          reprocessedReq.getSecondType().dump(llvm::errs());
-          llvm::errs() << "\n";
-          break;
-        }
-      }
-    }
-
-    llvm_unreachable("idempotency problem with a generic signature");
-  }
-#else
-  // FIXME: This should be handled lazily in the future, and therefore not
-  // required.
-  builder->processDelayedRequirements();
-#endif
-
-  return builder;
-}
-
 rewriting::RewriteContext &
 ASTContext::getRewriteContext() {
   auto &rewriteCtx = getImpl().TheRewriteContext;
diff --git a/lib/AST/GenericSignature.cpp b/lib/AST/GenericSignature.cpp
index c16e66c068c6f..0ef013c6ef333 100644
--- a/lib/AST/GenericSignature.cpp
+++ b/lib/AST/GenericSignature.cpp
@@ -24,8 +24,6 @@
 #include "swift/AST/Types.h"
 #include "swift/Basic/SourceManager.h"
 #include "swift/Basic/STLExtras.h"
-#include "GenericSignatureBuilder.h"
-#include "GenericSignatureBuilderImpl.h"
 #include "RequirementMachine/RequirementMachine.h"
 #include <functional>
 
@@ -182,17 +180,6 @@ ArrayRef<Requirement> GenericSignature::getRequirements() const {
       : getPointer()->getRequirements();
 }
 
-GenericSignatureBuilder *
-GenericSignatureImpl::getGenericSignatureBuilder() const {
-  // The generic signature builder is associated with the canonical signature.
-  if (!isCanonical())
-    return getCanonicalSignature()->getGenericSignatureBuilder();
-
-  // generic signature builders are stored on the ASTContext.
-  return getASTContext().getOrCreateGenericSignatureBuilder(
-                                             CanGenericSignature(this));
-}
-
 rewriting::RequirementMachine *
 GenericSignatureImpl::getRequirementMachine() const {
   if (Machine)
@@ -290,156 +277,8 @@ GenericSignature::LocalRequirements
 GenericSignatureImpl::getLocalRequirements(Type depType) const {
   assert(depType->isTypeParameter() && "Expected a type parameter here");
 
-  auto computeViaGSB = [&]() {
-    GenericSignature::LocalRequirements result;
-
-    auto &builder = *getGenericSignatureBuilder();
-
-    auto resolved =
-      builder.maybeResolveEquivalenceClass(
-                                    depType,
-                                    ArchetypeResolutionKind::CompleteWellFormed,
-                                    /*wantExactPotentialArchetype=*/false);
-    if (!resolved) {
-      result.concreteType = ErrorType::get(depType);
-      return result;
-    }
-
-    if (auto concreteType = resolved.getAsConcreteType()) {
-      result.concreteType = concreteType;
-      return result;
-    }
-
-    auto *equivClass = resolved.getEquivalenceClass(builder);
-
-    auto genericParams = getGenericParams();
-    result.anchor = equivClass->getAnchor(builder, genericParams);
-
-    if (equivClass->concreteType) {
-      result.concreteType = equivClass->concreteType;
-      return result;
-    }
-
-    result.superclass = equivClass->superclass;
-
-    for (const auto &conforms : equivClass->conformsTo) {
-      auto proto = conforms.first;
-
-      if (!equivClass->isConformanceSatisfiedBySuperclass(proto))
-        result.protos.push_back(proto);
-    }
-
-    result.layout = equivClass->layout;
-
-    return result;
-  };
-
-  auto computeViaRQM = [&]() {
-    auto *machine = getRequirementMachine();
-    return machine->getLocalRequirements(depType, getGenericParams());
-  };
-
-  auto &ctx = getASTContext();
-  switch (ctx.LangOpts.EnableRequirementMachine) {
-  case RequirementMachineMode::Disabled:
-    return computeViaGSB();
-
-  case RequirementMachineMode::Enabled:
-    return computeViaRQM();
-
-  case RequirementMachineMode::Verify: {
-    auto rqmResult = computeViaRQM();
-    auto gsbResult = computeViaGSB();
-
-    auto typesEqual = [&](Type lhs, Type rhs, bool canonical) {
-      if (!lhs || !rhs)
-        return !lhs == !rhs;
-      if (lhs->isEqual(rhs))
-        return true;
-
-      if (canonical)
-        return false;
-
-      if (getCanonicalTypeInContext(lhs) ==
-          getCanonicalTypeInContext(rhs))
-        return true;
-
-      return false;
-    };
-
-    auto compare = [&]() {
-      // If the types are concrete, we don't care about the rest.
-      if (gsbResult.concreteType || rqmResult.concreteType) {
-        if (!typesEqual(gsbResult.concreteType,
-                        rqmResult.concreteType,
-                        false))
-          return false;
-
-        return true;
-      }
-
-      if (!typesEqual(gsbResult.anchor,
-                      rqmResult.anchor,
-                      true))
-        return false;
-
-      if (gsbResult.layout != rqmResult.layout)
-        return false;
-
-      auto lhsProtos = gsbResult.protos;
-      ProtocolType::canonicalizeProtocols(lhsProtos);
-      auto rhsProtos = rqmResult.protos;
-      ProtocolType::canonicalizeProtocols(rhsProtos);
-
-      if (lhsProtos != rhsProtos)
-        return false;
-
-      if (!typesEqual(gsbResult.superclass,
-                      rqmResult.superclass,
-                      false))
-        return false;
-
-      return true;
-    };
-
-    auto dumpReqs = [&](const GenericSignature::LocalRequirements &reqs) {
-      if (reqs.anchor) {
-        llvm::errs() << "- Anchor: " << reqs.anchor << "\n";
-        reqs.anchor.dump(llvm::errs());
-      }
-      if (reqs.concreteType) {
-        llvm::errs() << "- Concrete type: " << reqs.concreteType << "\n";
-        reqs.concreteType.dump(llvm::errs());
-      }
-      if (reqs.superclass) {
-        llvm::errs() << "- Superclass: " << reqs.superclass << "\n";
-        reqs.superclass.dump(llvm::errs());
-      }
-      if (reqs.layout) {
-        llvm::errs() << "- Layout: " << reqs.layout << "\n";
-      }
-      for (const auto *proto : reqs.protos) {
-        llvm::errs() << "- Conforms to: " << proto->getName() << "\n";
-      }
-    };
-
-    if (!compare()) {
-      llvm::errs() << "RequirementMachine::getLocalRequirements() is broken\n";
-      llvm::errs() << "Generic signature: " << GenericSignature(this) << "\n";
-      llvm::errs() << "Dependent type: "; depType.dump(llvm::errs());
-      llvm::errs() << "GenericSignatureBuilder says:\n";
-      dumpReqs(gsbResult);
-      llvm::errs() << "\n";
-      llvm::errs() << "RequirementMachine says:\n";
-      dumpReqs(rqmResult);
-      llvm::errs() << "\n";
-      getRequirementMachine()->dump(llvm::errs());
-      abort();
-    }
-
-    return rqmResult;
-  }
-  }
+  return getRequirementMachine()->getLocalRequirements(
+      depType, getGenericParams());
 }
 
 ASTContext &GenericSignatureImpl::getASTContext() const {
@@ -467,54 +306,7 @@ bool GenericSignatureImpl::requiresClass(Type type) const {
   assert(type->isTypeParameter() &&
          "Only type parameters can have superclass requirements");
 
-  auto computeViaGSB = [&]() {
-    auto &builder = *getGenericSignatureBuilder();
-    auto equivClass =
-      builder.resolveEquivalenceClass(
-                                    type,
-                                    ArchetypeResolutionKind::CompleteWellFormed);
-    if (!equivClass) return false;
-
-    // If this type was mapped to a concrete type, then there is no
-    // requirement.
-    if (equivClass->concreteType) return false;
-
-    // If there is a layout constraint, it might be a class.
-    if (equivClass->layout && equivClass->layout->isClass()) return true;
-
-    return false;
-  };
-
-  auto computeViaRQM = [&]() {
-    auto *machine = getRequirementMachine();
-    return machine->requiresClass(type);
-  };
-
-  auto &ctx = getASTContext();
-  switch (ctx.LangOpts.EnableRequirementMachine) {
-  case RequirementMachineMode::Disabled:
-    return computeViaGSB();
-
-  case RequirementMachineMode::Enabled:
-    return computeViaRQM();
-
-  case RequirementMachineMode::Verify: {
-    auto rqmResult = computeViaRQM();
-    auto gsbResult = computeViaGSB();
-
-    if (gsbResult != rqmResult) {
-      llvm::errs() << "RequirementMachine::requiresClass() is broken\n";
-      llvm::errs() << "Generic signature: " << GenericSignature(this) << "\n";
-      llvm::errs() << "Dependent type: "; type.dump(llvm::errs());
-      llvm::errs() << "GenericSignatureBuilder says: " << gsbResult << "\n";
-      llvm::errs() << "RequirementMachine says: " << rqmResult << "\n";
-      getRequirementMachine()->dump(llvm::errs());
-      abort();
-    }
-
-    return rqmResult;
-  }
-  }
+  return getRequirementMachine()->requiresClass(type);
 }
 
 /// Determine the superclass bound on the given dependent type.
@@ -522,64 +314,8 @@ Type GenericSignatureImpl::getSuperclassBound(Type type) const {
   assert(type->isTypeParameter() &&
          "Only type parameters can have superclass requirements");
 
-  auto computeViaGSB = [&]() -> Type {
-    auto &builder = *getGenericSignatureBuilder();
-    auto equivClass =
-    builder.resolveEquivalenceClass(
-                                  type,
-                                  ArchetypeResolutionKind::CompleteWellFormed);
-    if (!equivClass) return nullptr;
-
-    // If this type was mapped to a concrete type, then there is no
-    // requirement.
-    if (equivClass->concreteType) return nullptr;
-
-    // Retrieve the superclass bound.
-    return equivClass->superclass;
-  };
-
-  auto computeViaRQM = [&]() {
-    auto *machine = getRequirementMachine();
-    return machine->getSuperclassBound(type, getGenericParams());
-  };
-
-  auto &ctx = getASTContext();
-  switch (ctx.LangOpts.EnableRequirementMachine) {
-  case RequirementMachineMode::Disabled:
-    return computeViaGSB();
-
-  case RequirementMachineMode::Enabled:
-    return computeViaRQM();
-
-  case RequirementMachineMode::Verify: {
-    auto rqmResult = computeViaRQM();
-    auto gsbResult = computeViaGSB();
-
-    auto check = [&]() {
-      if (!gsbResult || !rqmResult)
-        return !gsbResult == !rqmResult;
-      return gsbResult->isEqual(rqmResult);
-    };
-
-    if (!check()) {
-      llvm::errs() << "RequirementMachine::getSuperclassBound() is broken\n";
-      llvm::errs() << "Generic signature: " << GenericSignature(this) << "\n";
-      llvm::errs() << "Dependent type: "; type.dump(llvm::errs());
-      llvm::errs() << "GenericSignatureBuilder says: " << gsbResult << "\n";
-      if (gsbResult)
-        gsbResult.dump(llvm::errs());
-      llvm::errs() << "\n";
-      llvm::errs() << "RequirementMachine says: " << rqmResult << "\n";
-      if (rqmResult)
-        rqmResult.dump(llvm::errs());
-      llvm::errs() << "\n";
-      getRequirementMachine()->dump(llvm::errs());
-      abort();
-    }
-
-    return rqmResult;
-  }
-  }
+  return getRequirementMachine()->getSuperclassBound(
+      type, getGenericParams());
 }
 
 /// Determine the set of protocols to which the given type parameter is
@@ -588,170 +324,21 @@ GenericSignature::RequiredProtocols
 GenericSignatureImpl::getRequiredProtocols(Type type) const {
   assert(type->isTypeParameter() && "Expected a type parameter");
 
-  auto computeViaGSB = [&]() -> GenericSignature::RequiredProtocols {
-    auto &builder = *getGenericSignatureBuilder();
-    auto equivClass =
-      builder.resolveEquivalenceClass(
-                                    type,
-                                    ArchetypeResolutionKind::CompleteWellFormed);
-    if (!equivClass) return { };
-
-    // If this type parameter was mapped to a concrete type, then there
-    // are no requirements.
-    if (equivClass->concreteType) return { };
-
-    // Retrieve the protocols to which this type conforms.
-    GenericSignature::RequiredProtocols result;
-    for (const auto &conforms : equivClass->conformsTo)
-      result.push_back(conforms.first);
-
-    // Canonicalize the resulting set of protocols.
-    ProtocolType::canonicalizeProtocols(result);
-
-    return result;
-  };
-
-  auto computeViaRQM = [&]() {
-    auto *machine = getRequirementMachine();
-    return machine->getRequiredProtocols(type);
-  };
-
-  auto &ctx = getASTContext();
-  switch (ctx.LangOpts.EnableRequirementMachine) {
-  case RequirementMachineMode::Disabled:
-    return computeViaGSB();
-
-  case RequirementMachineMode::Enabled:
-    return computeViaRQM();
-
-  case RequirementMachineMode::Verify: {
-    auto rqmResult = computeViaRQM();
-    auto gsbResult = computeViaGSB();
-
-    if (gsbResult != rqmResult) {
-      llvm::errs() << "RequirementMachine::getRequiredProtocols() is broken\n";
-      llvm::errs() << "Generic signature: " << GenericSignature(this) << "\n";
-      llvm::errs() << "Dependent type: "; type.dump(llvm::errs());
-      llvm::errs() << "GenericSignatureBuilder says: ";
-      for (auto *otherProto : gsbResult)
-        llvm::errs() << " " << otherProto->getName();
-      llvm::errs() << "\n";
-      llvm::errs() << "RequirementMachine says: ";
-      for (auto *otherProto : rqmResult)
-        llvm::errs() << " " << otherProto->getName();
-      llvm::errs() << "\n";
-      getRequirementMachine()->dump(llvm::errs());
-      abort();
-    }
-
-    return rqmResult;
-  }
-  }
+  return getRequirementMachine()->getRequiredProtocols(type);
 }
 
 bool GenericSignatureImpl::requiresProtocol(Type type,
                                             ProtocolDecl *proto) const {
   assert(type->isTypeParameter() && "Expected a type parameter");
 
-  auto computeViaGSB = [&]() {
-    auto &builder = *getGenericSignatureBuilder();
-    auto equivClass =
-      builder.resolveEquivalenceClass(
-                                    type,
-                                    ArchetypeResolutionKind::CompleteWellFormed);
-    if (!equivClass) return false;
-
-    // FIXME: Optionally deal with concrete conformances here
-    // or have a separate method do that additionally?
-    //
-    // If this type parameter was mapped to a concrete type, then there
-    // are no requirements.
-    if (equivClass->concreteType) return false;
-
-    // Check whether the representative conforms to this protocol.
-    return equivClass->conformsTo.count(proto) > 0;
-  };
-
-  auto computeViaRQM = [&]() {
-    auto *machine = getRequirementMachine();
-    return machine->requiresProtocol(type, proto);
-  };
-
-  auto &ctx = getASTContext();
-  switch (ctx.LangOpts.EnableRequirementMachine) {
-  case RequirementMachineMode::Disabled:
-    return computeViaGSB();
-
-  case RequirementMachineMode::Enabled:
-    return computeViaRQM();
-
-  case RequirementMachineMode::Verify: {
-    auto rqmResult = computeViaRQM();
-    auto gsbResult = computeViaGSB();
-
-    if (gsbResult != rqmResult) {
-      llvm::errs() << "RequirementMachine::requiresProtocol() is broken\n";
-      llvm::errs() << "Generic signature: " << GenericSignature(this) << "\n";
-      llvm::errs() << "Dependent type: "; type.dump(llvm::errs());
-      llvm::errs() << "Protocol: "; proto->dumpRef(llvm::errs());
-      llvm::errs() << "\n";
-      llvm::errs() << "GenericSignatureBuilder says: " << gsbResult << "\n";
-      llvm::errs() << "RequirementMachine says: " << rqmResult << "\n";
-      getRequirementMachine()->dump(llvm::errs());
-      abort();
-    }
-
-    return rqmResult;
-  }
-  }
+  return getRequirementMachine()->requiresProtocol(type, proto);
 }
 
 /// Determine whether the given dependent type is equal to a concrete type.
 bool GenericSignatureImpl::isConcreteType(Type type) const {
   assert(type->isTypeParameter() && "Expected a type parameter");
 
-  auto computeViaGSB = [&]() {
-    auto &builder = *getGenericSignatureBuilder();
-    auto equivClass =
-      builder.resolveEquivalenceClass(
-                                    type,
-                                    ArchetypeResolutionKind::CompleteWellFormed);
-    if (!equivClass) return false;
-
-    return bool(equivClass->concreteType);
-  };
-
-  auto computeViaRQM = [&]() {
-    auto *machine = getRequirementMachine();
-    return machine->isConcreteType(type);
-  };
-
-  auto &ctx = getASTContext();
-  switch (ctx.LangOpts.EnableRequirementMachine) {
-  case RequirementMachineMode::Disabled:
-    return computeViaGSB();
-
-  case RequirementMachineMode::Enabled:
-    return computeViaRQM();
-
-  case RequirementMachineMode::Verify: {
-    auto rqmResult = computeViaRQM();
-    auto gsbResult = computeViaGSB();
-
-    if (gsbResult != rqmResult) {
-      llvm::errs() << "RequirementMachine::isConcreteType() is broken\n";
-      llvm::errs() << "Generic signature: " << GenericSignature(this) << "\n";
-      llvm::errs() << "Dependent type: "; type.dump(llvm::errs());
-      llvm::errs() << "\n";
-      llvm::errs() << "GenericSignatureBuilder says: " << gsbResult << "\n";
-      llvm::errs() << "RequirementMachine says: " << rqmResult << "\n";
-      getRequirementMachine()->dump(llvm::errs());
-      abort();
-    }
-
-    return rqmResult;
-  }
-  }
+  return getRequirementMachine()->isConcreteType(type);
 }
 
 /// Return the concrete type that the given type parameter is constrained to,
@@ -760,111 +347,14 @@ bool GenericSignatureImpl::isConcreteType(Type type) const {
 Type GenericSignatureImpl::getConcreteType(Type type) const {
   assert(type->isTypeParameter() && "Expected a type parameter");
 
-  auto computeViaGSB = [&]() -> Type {
-    auto &builder = *getGenericSignatureBuilder();
-    auto equivClass =
-    builder.resolveEquivalenceClass(
-                                  type,
-                                  ArchetypeResolutionKind::CompleteWellFormed);
-    if (!equivClass) return nullptr;
-
-    return equivClass->concreteType;
-  };
-
-  auto computeViaRQM = [&]() {
-    auto *machine = getRequirementMachine();
-    return machine->getConcreteType(type, getGenericParams());
-  };
-
-  auto &ctx = getASTContext();
-  switch (ctx.LangOpts.EnableRequirementMachine) {
-  case RequirementMachineMode::Disabled:
-    return computeViaGSB();
-
-  case RequirementMachineMode::Enabled:
-    return computeViaRQM();
-
-  case RequirementMachineMode::Verify: {
-    auto rqmResult = computeViaRQM();
-    auto gsbResult = computeViaGSB();
-
-    auto check = [&]() {
-      if (!gsbResult || !rqmResult)
-        return !gsbResult == !rqmResult;
-      if (gsbResult->isEqual(rqmResult))
-        return true;
-
-      return (getCanonicalTypeInContext(gsbResult)
-              == getCanonicalTypeInContext(rqmResult));
-    };
-
-    if (!check()) {
-      llvm::errs() << "RequirementMachine::getConcreteType() is broken\n";
-      llvm::errs() << "Generic signature: " << GenericSignature(this) << "\n";
-      llvm::errs() << "Dependent type: "; type.dump(llvm::errs());
-      llvm::errs() << "GenericSignatureBuilder says: " << gsbResult << "\n";
-      if (gsbResult)
-        gsbResult.dump(llvm::errs());
-      llvm::errs() << "\n";
-      llvm::errs() << "RequirementMachine says: " << rqmResult << "\n";
-      if (rqmResult)
-        rqmResult.dump(llvm::errs());
-      llvm::errs() << "\n";
-      getRequirementMachine()->dump(llvm::errs());
-      abort();
-    }
-
-    return rqmResult;
-  }
-  }
+  return getRequirementMachine()->getConcreteType(type, getGenericParams());
 }
 
 LayoutConstraint GenericSignatureImpl::getLayoutConstraint(Type type) const {
   assert(type->isTypeParameter() &&
          "Only type parameters can have layout constraints");
 
-  auto computeViaGSB = [&]() {
-    auto &builder = *getGenericSignatureBuilder();
-    auto equivClass =
-      builder.resolveEquivalenceClass(
-                                    type,
-                                    ArchetypeResolutionKind::CompleteWellFormed);
-    if (!equivClass) return LayoutConstraint();
-
-    return equivClass->layout;
-  };
-
-  auto computeViaRQM = [&]() {
-    auto *machine = getRequirementMachine();
-    return machine->getLayoutConstraint(type);
-  };
-
-  auto &ctx = getASTContext();
-  switch (ctx.LangOpts.EnableRequirementMachine) {
-  case RequirementMachineMode::Disabled:
-    return computeViaGSB();
-
-  case RequirementMachineMode::Enabled:
-    return computeViaRQM();
-
-  case RequirementMachineMode::Verify: {
-    auto rqmResult = computeViaRQM();
-    auto gsbResult = computeViaGSB();
-
-    if (gsbResult != rqmResult) {
-      llvm::errs() << "RequirementMachine::getLayoutConstraint() is broken\n";
-      llvm::errs() << "Generic signature: " << GenericSignature(this) << "\n";
-      llvm::errs() << "Dependent type: "; type.dump(llvm::errs());
-      llvm::errs() << "\n";
-      llvm::errs() << "GenericSignatureBuilder says: " << gsbResult << "\n";
-      llvm::errs() << "RequirementMachine says: " << rqmResult << "\n";
-      getRequirementMachine()->dump(llvm::errs());
-      abort();
-    }
-
-    return rqmResult;
-  }
-  }
+  return getRequirementMachine()->getLayoutConstraint(type);
 }
 
 bool GenericSignatureImpl::areSameTypeParameterInContext(Type type1,
@@ -875,71 +365,7 @@ bool GenericSignatureImpl::areSameTypeParameterInContext(Type type1,
   if (type1.getPointer() == type2.getPointer())
     return true;
 
-  auto computeViaGSB = [&]() {
-    return areSameTypeParameterInContext(type1, type2,
-                                         *getGenericSignatureBuilder());
-  };
-
-  auto computeViaRQM = [&]() {
-    auto *machine = getRequirementMachine();
-    return machine->areSameTypeParameterInContext(type1, type2);
-  };
-
-  auto &ctx = getASTContext();
-  switch (ctx.LangOpts.EnableRequirementMachine) {
-  case RequirementMachineMode::Disabled:
-    return computeViaGSB();
-
-  case RequirementMachineMode::Enabled:
-    return computeViaRQM();
-
-  case RequirementMachineMode::Verify: {
-    auto rqmResult = computeViaRQM();
-    auto gsbResult = computeViaGSB();
-
-    if (gsbResult != rqmResult) {
-      auto firstConcreteType = getConcreteType(type1);
-      auto secondConcreteType = getConcreteType(type2);
-      if (!firstConcreteType->isEqual(secondConcreteType)) {
-        llvm::errs() << "RequirementMachine::areSameTypeParameterInContext() is broken\n";
-        llvm::errs() << "Generic signature: " << GenericSignature(this) << "\n";
-        llvm::errs() << "First dependent type: "; type1.dump(llvm::errs());
-        llvm::errs() << "Second dependent type: "; type2.dump(llvm::errs());
-        llvm::errs() << "\n";
-        llvm::errs() << "GenericSignatureBuilder says: " << gsbResult << "\n";
-        llvm::errs() << "RequirementMachine says: " << rqmResult << "\n";
-        getRequirementMachine()->dump(llvm::errs());
-        abort();
-      }
-    }
-
-    return rqmResult;
-  }
-  }
-}
-
-bool GenericSignatureImpl::areSameTypeParameterInContext(Type type1,
-                                                         Type type2,
-                                                         GenericSignatureBuilder &builder) const {
-  assert(type1->isTypeParameter());
-  assert(type2->isTypeParameter());
-
-  if (type1.getPointer() == type2.getPointer())
-    return true;
-
-  auto equivClass1 =
-    builder.resolveEquivalenceClass(
-                             type1,
-                             ArchetypeResolutionKind::CompleteWellFormed);
-  assert(equivClass1 && "not a valid dependent type of this signature?");
-
-  auto equivClass2 =
-    builder.resolveEquivalenceClass(
-                             type2,
-                             ArchetypeResolutionKind::CompleteWellFormed);
-  assert(equivClass2 && "not a valid dependent type of this signature?");
-
-  return equivClass1 == equivClass2;
+  return getRequirementMachine()->areSameTypeParameterInContext(type1, type2);
 }
 
 bool GenericSignatureImpl::isRequirementSatisfied(
@@ -1016,70 +442,7 @@ bool GenericSignatureImpl::isCanonicalTypeInContext(Type type) const {
   if (!type->hasTypeParameter())
     return true;
 
-  auto computeViaGSB = [&]() {
-    auto &builder = *getGenericSignatureBuilder();
-    return isCanonicalTypeInContext(type, builder);
-  };
-
-  auto computeViaRQM = [&]() {
-    auto *machine = getRequirementMachine();
-    return machine->isCanonicalTypeInContext(type);
-  };
-
-  auto &ctx = getASTContext();
-  switch (ctx.LangOpts.EnableRequirementMachine) {
-  case RequirementMachineMode::Disabled:
-    return computeViaGSB();
-
-  case RequirementMachineMode::Enabled:
-    return computeViaRQM();
-
-  case RequirementMachineMode::Verify: {
-    auto rqmResult = computeViaRQM();
-    auto gsbResult = computeViaGSB();
-
-    if (gsbResult != rqmResult) {
-      llvm::errs() << "RequirementMachine::isCanonicalTypeInContext() is broken\n";
-      llvm::errs() << "Generic signature: " << GenericSignature(this) << "\n";
-      llvm::errs() << "Dependent type: "; type.dump(llvm::errs());
-      llvm::errs() << "\n";
-      llvm::errs() << "GenericSignatureBuilder says: " << gsbResult << "\n";
-      llvm::errs() << "RequirementMachine says: " << rqmResult << "\n";
-      getRequirementMachine()->dump(llvm::errs());
-      abort();
-    }
-
-    return rqmResult;
-  }
-  }
-}
-
-bool GenericSignatureImpl::isCanonicalTypeInContext(
-    Type type, GenericSignatureBuilder &builder) const {
-  // If the type isn't independently canonical, it's certainly not canonical
-  // in this context.
-  if (!type->isCanonical())
-    return false;
-
-  // All the contextual canonicality rules apply to type parameters, so if the
-  // type doesn't involve any type parameters, it's already canonical.
-  if (!type->hasTypeParameter())
-    return true;
-
-  // Look for non-canonical type parameters.
-  return !type.findIf([&](Type component) -> bool {
-    if (!component->isTypeParameter()) return false;
-
-    auto equivClass =
-      builder.resolveEquivalenceClass(
-                               Type(component),
-                               ArchetypeResolutionKind::CompleteWellFormed);
-    if (!equivClass) return false;
-
-    return (equivClass->concreteType ||
-            !component->isEqual(equivClass->getAnchor(builder,
-                                                      getGenericParams())));
-  });
+  return getRequirementMachine()->isCanonicalTypeInContext(type);
 }
 
 CanType GenericSignature::getCanonicalTypeInContext(Type type) const {
@@ -1099,44 +462,8 @@ CanType GenericSignatureImpl::getCanonicalTypeInContext(Type type) const {
   if (!type->hasTypeParameter())
     return CanType(type);
 
-  auto computeViaGSB = [&]() {
-    auto &builder = *getGenericSignatureBuilder();
-    return builder.getCanonicalTypeInContext(type, { })->getCanonicalType();
-  };
-
-  auto computeViaRQM = [&]() {
-    auto *machine = getRequirementMachine();
-    return machine->getCanonicalTypeInContext(type, { })->getCanonicalType();
-  };
-
-  auto &ctx = getASTContext();
-  switch (ctx.LangOpts.EnableRequirementMachine) {
-  case RequirementMachineMode::Disabled:
-    return computeViaGSB();
-
-  case RequirementMachineMode::Enabled:
-    return computeViaRQM();
-
-  case RequirementMachineMode::Verify: {
-    auto rqmResult = computeViaRQM();
-    auto gsbResult = computeViaGSB();
-
-    if (gsbResult != rqmResult) {
-      llvm::errs() << "RequirementMachine::getCanonicalTypeInContext() is broken\n";
-      llvm::errs() << "Generic signature: " << GenericSignature(this) << "\n";
-      llvm::errs() << "Dependent type: "; type.dump(llvm::errs());
-      llvm::errs() << "GenericSignatureBuilder says: " << gsbResult << "\n";
-      gsbResult.dump(llvm::errs());
-      llvm::errs() << "RequirementMachine says: " << rqmResult << "\n";
-      rqmResult.dump(llvm::errs());
-      llvm::errs() << "\n";
-      getRequirementMachine()->dump(llvm::errs());
-      abort();
-    }
-
-    return rqmResult;
-  }
-  }
+  return getRequirementMachine()->getCanonicalTypeInContext(
+      type, { })->getCanonicalType();
 }
 
 ArrayRef<CanTypeWrapper<GenericTypeParamType>>
@@ -1150,129 +477,14 @@ CanGenericSignature::getGenericParams() const {
 ConformanceAccessPath
 GenericSignatureImpl::getConformanceAccessPath(Type type,
                                                ProtocolDecl *protocol) const {
-  auto computeViaGSB = [&]() {
-    return getGenericSignatureBuilder()->getConformanceAccessPath(
-        type, protocol, this);
-  };
-
-  auto computeViaRQM = [&]() {
-    auto *machine = getRequirementMachine();
-    return machine->getConformanceAccessPath(type, protocol);
-  };
-
-  auto &ctx = getASTContext();
-  switch (ctx.LangOpts.EnableRequirementMachine) {
-  case RequirementMachineMode::Disabled:
-    return computeViaGSB();
-
-  case RequirementMachineMode::Enabled:
-    return computeViaRQM();
-
-  case RequirementMachineMode::Verify: {
-    auto rqmResult = computeViaRQM();
-    auto gsbResult = computeViaGSB();
-
-    auto compare = [&]() {
-      if (gsbResult.size() != rqmResult.size())
-        return false;
-
-      auto *begin1 = gsbResult.begin();
-      auto *end1 = gsbResult.end();
-      auto *begin2 = rqmResult.begin();
-      auto *end2 = rqmResult.end();
-
-      while (begin1 < end1) {
-        assert(begin2 < end2);
-
-        if (!begin1->first->isEqual(begin2->first))
-          return false;
-        if (begin1->second != begin2->second)
-          return false;
-
-        ++begin1;
-        ++begin2;
-      }
-
-      return true;
-    };
-
-    if (!compare()) {
-      llvm::errs() << "RequirementMachine::getConformanceAccessPath() is broken\n";
-      llvm::errs() << "Generic signature: " << GenericSignature(this) << "\n";
-      llvm::errs() << "Dependent type: "; type.dump(llvm::errs());
-      llvm::errs() << "Protocol: "; protocol->dumpRef(llvm::errs());
-      llvm::errs() << "\n";
-      llvm::errs() << "GenericSignatureBuilder says: ";
-      gsbResult.print(llvm::errs());
-      llvm::errs() << "\n";
-      llvm::errs() << "RequirementMachine says: ";
-      rqmResult.print(llvm::errs());
-      llvm::errs() << "\n\n";
-      getRequirementMachine()->dump(llvm::errs());
-      abort();
-    }
-
-    return rqmResult;
-  }
-  }
+  return getRequirementMachine()->getConformanceAccessPath(type, protocol);
 }
 
 TypeDecl *
 GenericSignatureImpl::lookupNestedType(Type type, Identifier name) const {
   assert(type->isTypeParameter());
 
-  auto computeViaGSB = [&]() -> TypeDecl * {
-    auto *builder = getGenericSignatureBuilder();
-    auto equivClass =
-      builder->resolveEquivalenceClass(
-                                  type,
-                                  ArchetypeResolutionKind::CompleteWellFormed);
-    if (!equivClass)
-      return nullptr;
-
-    return equivClass->lookupNestedType(*builder, name);
-  };
-
-  auto computeViaRQM = [&]() {
-    auto *machine = getRequirementMachine();
-    return machine->lookupNestedType(type, name);
-  };
-
-  auto &ctx = getASTContext();
-  switch (ctx.LangOpts.EnableRequirementMachine) {
-  case RequirementMachineMode::Disabled:
-    return computeViaGSB();
-
-  case RequirementMachineMode::Enabled:
-    return computeViaRQM();
-
-  case RequirementMachineMode::Verify: {
-    auto rqmResult = computeViaRQM();
-    auto gsbResult = computeViaGSB();
-
-    if (gsbResult != rqmResult) {
-      llvm::errs() << "RequirementMachine::lookupNestedType() is broken\n";
-      llvm::errs() << "Generic signature: " << GenericSignature(this) << "\n";
-      llvm::errs() << "Dependent type: "; type.dump(llvm::errs());
-      llvm::errs() << "GenericSignatureBuilder says: ";
-      if (gsbResult)
-        gsbResult->dumpRef(llvm::errs());
-      else
-        llvm::errs() << "<nullptr>";
-      llvm::errs() << "\n";
-      llvm::errs() << "RequirementMachine says: ";
-      if (rqmResult)
-        rqmResult->dumpRef(llvm::errs());
-      else
-        llvm::errs() << "<nullptr>";
-      llvm::errs() << "\n";
-      getRequirementMachine()->dump(llvm::errs());
-      abort();
-    }
-
-    return rqmResult;
-  }
-  }
+  return getRequirementMachine()->lookupNestedType(type, name);
 }
 
 unsigned GenericParamKey::findIndexIn(
diff --git a/lib/AST/GenericSignatureBuilder.cpp b/lib/AST/GenericSignatureBuilder.cpp
index 113f0eb15cab7..f223f310a0e61 100644
--- a/lib/AST/GenericSignatureBuilder.cpp
+++ b/lib/AST/GenericSignatureBuilder.cpp
@@ -703,12 +703,6 @@ struct GenericSignatureBuilder::Implementation {
 
   llvm::DenseSet<ExplicitRequirement> ExplicitConformancesImpliedByConcrete;
 
-  llvm::DenseMap<std::pair<CanType, ProtocolDecl *>,
-                 ConformanceAccessPath> ConformanceAccessPaths;
-
-  std::vector<std::pair<CanType, ConformanceAccessPath>>
-      CurrentConformanceAccessPaths;
-
 #ifndef NDEBUG
   /// Whether we've already computed redundant requiremnts.
   bool computedRedundantRequirements = false;
@@ -3776,127 +3770,6 @@ Type GenericSignatureBuilder::getCanonicalTypeInContext(Type type,
   });
 }
 
-ConformanceAccessPath
-GenericSignatureBuilder::getConformanceAccessPath(Type type,
-                                                  ProtocolDecl *protocol,
-                                                  GenericSignature sig) {
-  auto canType = getCanonicalTypeInContext(type, { })->getCanonicalType();
-  assert(canType->isTypeParameter());
-
-  // Check if we've already cached the result before doing anything else.
-  auto found = Impl->ConformanceAccessPaths.find(
-      std::make_pair(canType, protocol));
-  if (found != Impl->ConformanceAccessPaths.end()) {
-    return found->second;
-  }
-
-  auto *Stats = Context.Stats;
-
-  FrontendStatsTracer tracer(Stats, "get-conformance-access-path");
-
-  auto recordPath = [&](CanType type, ProtocolDecl *proto,
-                        ConformanceAccessPath path) {
-    // Add the path to the buffer.
-    Impl->CurrentConformanceAccessPaths.emplace_back(type, path);
-
-    // Add the path to the map.
-    auto key = std::make_pair(type, proto);
-    auto inserted = Impl->ConformanceAccessPaths.insert(
-        std::make_pair(key, path));
-    assert(inserted.second);
-    (void) inserted;
-
-    if (Stats)
-      ++Stats->getFrontendCounters().NumConformanceAccessPathsRecorded;
-  };
-
-  // If this is the first time we're asked to look up a conformance access path,
-  // visit all of the root conformance requirements in our generic signature and
-  // add them to the buffer.
-  if (Impl->ConformanceAccessPaths.empty()) {
-    for (const auto &req : sig.getRequirements()) {
-      // We only care about conformance requirements.
-      if (req.getKind() != RequirementKind::Conformance)
-        continue;
-
-      auto rootType = req.getFirstType()->getCanonicalType();
-      auto *rootProto = req.getProtocolDecl();
-
-      ConformanceAccessPath::Entry root(rootType, rootProto);
-      ArrayRef<ConformanceAccessPath::Entry> path(root);
-      ConformanceAccessPath result(Context.AllocateCopy(path));
-
-      recordPath(rootType, rootProto, result);
-    }
-  }
-
-  // We enumerate conformance access paths in lexshort order until we find the
-  // path whose corresponding type canonicalizes to the one we are looking for.
-  while (true) {
-    auto found = Impl->ConformanceAccessPaths.find(
-        std::make_pair(canType, protocol));
-    if (found != Impl->ConformanceAccessPaths.end()) {
-      return found->second;
-    }
-
-    assert(Impl->CurrentConformanceAccessPaths.size() > 0);
-
-    // The buffer consists of all conformance access paths of length N.
-    // Swap it out with an empty buffer, and fill it with all paths of
-    // length N+1.
-    std::vector<std::pair<CanType, ConformanceAccessPath>> oldPaths;
-    std::swap(Impl->CurrentConformanceAccessPaths, oldPaths);
-
-    for (const auto &pair : oldPaths) {
-      const auto &lastElt = pair.second.back();
-      auto *lastProto = lastElt.second;
-
-      // A copy of the current path, populated as needed.
-      SmallVector<ConformanceAccessPath::Entry, 4> entries;
-
-      for (const auto &req : lastProto->getRequirementSignature()) {
-        // We only care about conformance requirements.
-        if (req.getKind() != RequirementKind::Conformance)
-          continue;
-
-        auto nextSubjectType = req.getFirstType()->getCanonicalType();
-        auto *nextProto = req.getProtocolDecl();
-
-        // Compute the canonical anchor for this conformance requirement.
-        auto nextType = replaceSelfWithType(pair.first, nextSubjectType);
-        auto nextCanType = getCanonicalTypeInContext(nextType, { })
-            ->getCanonicalType();
-
-        // Skip "derived via concrete" sources.
-        if (!nextCanType->isTypeParameter())
-          continue;
-
-        // If we've already seen a path for this conformance, skip it and
-        // don't add it to the buffer. Note that because we iterate over
-        // conformance access paths in lexshort order, the existing
-        // conformance access path is shorter than the one we found just now.
-        if (Impl->ConformanceAccessPaths.count(
-                std::make_pair(nextCanType, nextProto)))
-          continue;
-
-        if (entries.empty()) {
-          // Fill our temporary vector.
-          entries.insert(entries.begin(),
-                         pair.second.begin(),
-                         pair.second.end());
-        }
-
-        // Add the next entry.
-        entries.emplace_back(nextSubjectType, nextProto);
-        ConformanceAccessPath result = Context.AllocateCopy(entries);
-        entries.pop_back();
-
-        recordPath(nextCanType, nextProto, result);
-      }
-    }
-  }
-}
-
 TypeArrayView<GenericTypeParamType>
 GenericSignatureBuilder::getGenericParams() const {
   return TypeArrayView<GenericTypeParamType>(Impl->GenericParams);
@@ -8322,20 +8195,6 @@ GenericSignature GenericSignatureBuilder::computeGenericSignature(
 
   bool hadAnyError = Impl->HadAnyError;
 
-  // When we can, move this generic signature builder to make it the canonical
-  // builder, rather than constructing a new generic signature builder that
-  // will produce the same thing.
-  //
-  // We cannot do this when there were errors.
-  //
-  // Also, we cannot do this when building a requirement signature.
-  if (requirementSignatureSelfProto == nullptr &&
-      !hadAnyError) {
-    // Register this generic signature builder as the canonical builder for the
-    // given signature.
-    Context.registerGenericSignatureBuilder(sig, std::move(*this));
-  }
-
   // Wipe out the internal state, ensuring that nobody uses this builder for
   // anything more.
   Impl.reset();
diff --git a/lib/AST/GenericSignatureBuilder.h b/lib/AST/GenericSignatureBuilder.h
index ed62e018daff2..42637986165e8 100644
--- a/lib/AST/GenericSignatureBuilder.h
+++ b/lib/AST/GenericSignatureBuilder.h
@@ -788,22 +788,6 @@ class GenericSignatureBuilder {
   Type getCanonicalTypeInContext(Type type,
                             TypeArrayView<GenericTypeParamType> genericParams);
 
-  /// Retrieve the conformance access path used to extract the conformance of
-  /// interface \c type to the given \c protocol.
-  ///
-  /// \param type The interface type whose conformance access path is to be
-  /// queried.
-  /// \param protocol A protocol to which \c type conforms.
-  ///
-  /// \returns the conformance access path that starts at a requirement of
-  /// this generic signature and ends at the conformance that makes \c type
-  /// conform to \c protocol.
-  ///
-  /// \seealso ConformanceAccessPath
-  ConformanceAccessPath getConformanceAccessPath(Type type,
-                                                 ProtocolDecl *protocol,
-                                                 GenericSignature sig);
-
   /// Dump all of the requirements, both specified and inferred. It cannot be
   /// statically proven that this doesn't modify the GSB.
   SWIFT_DEBUG_HELPER(void dump());
diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index 86843f4ec20ff..7b27efdac2d79 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -854,20 +854,6 @@ static bool ParseLangArgs(LangOptions &Opts, ArgList &Args,
   Opts.DisableSubstSILFunctionTypes =
       Args.hasArg(OPT_disable_subst_sil_function_types);
 
-  if (auto A = Args.getLastArg(OPT_requirement_machine_EQ)) {
-    auto value = llvm::StringSwitch<Optional<RequirementMachineMode>>(A->getValue())
-        .Case("off", RequirementMachineMode::Disabled)
-        .Case("on", RequirementMachineMode::Enabled)
-        .Case("verify", RequirementMachineMode::Verify)
-        .Default(None);
-
-    if (value)
-      Opts.EnableRequirementMachine = *value;
-    else
-      Diags.diagnose(SourceLoc(), diag::error_invalid_arg_value,
-                     A->getAsString(Args), A->getValue());
-  }
-
   if (auto A = Args.getLastArg(OPT_requirement_machine_protocol_signatures_EQ)) {
     auto value = llvm::StringSwitch<Optional<RequirementMachineMode>>(A->getValue())
         .Case("off", RequirementMachineMode::Disabled)
diff --git a/test/Generics/ambiguous_protocol_inheritance.swift b/test/Generics/ambiguous_protocol_inheritance.swift
index 47aff4d32d264..91ecc5062be7e 100644
--- a/test/Generics/ambiguous_protocol_inheritance.swift
+++ b/test/Generics/ambiguous_protocol_inheritance.swift
@@ -1,4 +1,4 @@
-// RUN: %target-typecheck-verify-swift -requirement-machine=verify
+// RUN: %target-typecheck-verify-swift
 
 protocol Base { // expected-note {{'Base' previously declared here}}
 // expected-note@-1 {{found this candidate}}
diff --git a/test/Generics/associated_type_order.swift b/test/Generics/associated_type_order.swift
index 50eebf6d21d85..da0a61474ac03 100644
--- a/test/Generics/associated_type_order.swift
+++ b/test/Generics/associated_type_order.swift
@@ -1,4 +1,4 @@
-// RUN: %target-swift-emit-silgen %s -requirement-machine=on | %FileCheck %s
+// RUN: %target-swift-emit-silgen %s | %FileCheck %s
 
 protocol P1 {
   associatedtype B
diff --git a/test/Generics/concrete_type_property_of_suffix.swift b/test/Generics/concrete_type_property_of_suffix.swift
index c080298060b79..a66efbf257792 100644
--- a/test/Generics/concrete_type_property_of_suffix.swift
+++ b/test/Generics/concrete_type_property_of_suffix.swift
@@ -1,4 +1,4 @@
-// RUN: %target-typecheck-verify-swift -requirement-machine=verify
+// RUN: %target-typecheck-verify-swift
 
 protocol P {
   associatedtype T where T == U?
diff --git a/test/Generics/conditional_requirement_inference.swift b/test/Generics/conditional_requirement_inference.swift
index 9dc517e386e1f..8de9c97bfadca 100644
--- a/test/Generics/conditional_requirement_inference.swift
+++ b/test/Generics/conditional_requirement_inference.swift
@@ -1,5 +1,5 @@
-// RUN: %target-typecheck-verify-swift -requirement-machine=on
-// RUN: not %target-swift-frontend -typecheck -debug-generic-signatures -requirement-machine=on %s 2>&1 | %FileCheck %s
+// RUN: %target-typecheck-verify-swift
+// RUN: not %target-swift-frontend -typecheck -debug-generic-signatures %s 2>&1 | %FileCheck %s
 
 
 // Valid example
@@ -55,4 +55,4 @@ func mergeP1AndP2<T : P1 & P2>(_: T) {
   takesP(T.R.T.self) // expected-error {{global function 'takesP' requires that 'T.R.T' conform to 'P'}}
   takesP(T.R.R.T.self) // expected-error {{global function 'takesP' requires that 'T.R.R.T' conform to 'P'}}
   takesP(T.R.R.R.T.self) // expected-error {{global function 'takesP' requires that 'T.R.R.R.T' conform to 'P'}}
-}
\ No newline at end of file
+}
diff --git a/test/Generics/generic_objc_superclass.swift b/test/Generics/generic_objc_superclass.swift
index 98e658b52a87c..802d2c1ae7baf 100644
--- a/test/Generics/generic_objc_superclass.swift
+++ b/test/Generics/generic_objc_superclass.swift
@@ -1,4 +1,4 @@
-// RUN: %target-typecheck-verify-swift %clang-importer-sdk -requirement-machine=verify -dump-requirement-machine 2>&1 | %FileCheck %s
+// RUN: %target-typecheck-verify-swift %clang-importer-sdk -dump-requirement-machine 2>&1 | %FileCheck %s
 
 // REQUIRES: objc_interop
 
diff --git a/test/Generics/gsb_canonical_type_bug_1.swift b/test/Generics/gsb_canonical_type_bug_1.swift
index 792f582db4fdc..58b03e6c35526 100644
--- a/test/Generics/gsb_canonical_type_bug_1.swift
+++ b/test/Generics/gsb_canonical_type_bug_1.swift
@@ -1,4 +1,4 @@
-// RUN: %target-swift-emit-silgen %s -requirement-machine=on | %FileCheck %s
+// RUN: %target-swift-emit-silgen %s | %FileCheck %s
 
 // The GSB computes an incorrect canonical type here, which caused a SILGen assert.
 
diff --git a/test/Generics/gsb_canonical_type_bug_2.swift b/test/Generics/gsb_canonical_type_bug_2.swift
index 810743c1022f4..37a4a7ec4b71b 100644
--- a/test/Generics/gsb_canonical_type_bug_2.swift
+++ b/test/Generics/gsb_canonical_type_bug_2.swift
@@ -1,6 +1,4 @@
-// RUN: %target-swift-emit-silgen %s -requirement-machine=on | %FileCheck %s
-// RUN: %target-swift-emit-silgen %s -requirement-machine=off | %FileCheck %s --check-prefix=CHECK-GSB
-// RUN: not --crash %target-swift-emit-silgen %s -requirement-machine=verify
+// RUN: %target-swift-emit-silgen %s | %FileCheck %s
 
 protocol P1 {
   associatedtype A
@@ -23,4 +21,3 @@ extension P2 {
 }
 
 // CHECK-LABEL:     sil hidden [ossa] @$s24gsb_canonical_type_bug_22P2PAAE3fooyyqd___1AQztAA2P1Rd__AA2P3Rd__1BAaHPQyd__Rsd__AeaGPQyd__AFRSlF : $@convention(method) <Self where Self : P2><T where T : P1, T : P3, T == T.B, Self.A == T.A> (@in_guaranteed T, @in_guaranteed Self.A, @in_guaranteed Self) -> ()
-// CHECK-GSB-LABEL: sil hidden [ossa] @$s24gsb_canonical_type_bug_22P2PAAE3fooyyqd___1AAA2P1PQyd__tAaFRd__AA2P3Rd__1BAaIPQyd__Rsd__AhERtzlF : $@convention(method) <Self where Self : P2><T where T : P1, T : P3, T == T.B, Self.A == T.A> (@in_guaranteed T, @in_guaranteed T.A, @in_guaranteed Self) -> ()
diff --git a/test/Generics/gsb_canonical_type_bug_3.swift b/test/Generics/gsb_canonical_type_bug_3.swift
index 200f428f20d3a..b4e3220f442ae 100644
--- a/test/Generics/gsb_canonical_type_bug_3.swift
+++ b/test/Generics/gsb_canonical_type_bug_3.swift
@@ -1,4 +1,4 @@
-// RUN: %target-swift-emit-silgen %s -requirement-machine=on | %FileCheck %s
+// RUN: %target-swift-emit-silgen %s | %FileCheck %s
 
 // The GSB computes an incorrect canonical type for bar() which causes
 // SILGen to assert.
diff --git a/test/Generics/member_type_of_superclass_bound.swift b/test/Generics/member_type_of_superclass_bound.swift
index 881faf2ab9bf4..3d482dd5a8d4d 100644
--- a/test/Generics/member_type_of_superclass_bound.swift
+++ b/test/Generics/member_type_of_superclass_bound.swift
@@ -1,4 +1,4 @@
-// RUN: %target-swift-emit-silgen %s -requirement-machine=verify
+// RUN: %target-swift-emit-silgen %s
 
 // The substituted type of SS.x.x is computed by taking the type of S.x,
 // which is T.T in the generic signature <T where T : P>, and then
diff --git a/test/Generics/rdar79564324.swift b/test/Generics/rdar79564324.swift
index c865bc2f5387d..7d7869a10b312 100644
--- a/test/Generics/rdar79564324.swift
+++ b/test/Generics/rdar79564324.swift
@@ -1,6 +1,6 @@
 // RUN: %empty-directory(%t)
-// RUN: %target-swift-frontend -emit-module %S/Inputs/rdar79564324_other.swift -emit-module-path %t/rdar79564324_other.swiftmodule -requirement-machine=on -dump-requirement-machine 2>&1 | %FileCheck %s
-// RUN: %target-swift-frontend -emit-silgen %s -I %t -requirement-machine=on
+// RUN: %target-swift-frontend -emit-module %S/Inputs/rdar79564324_other.swift -emit-module-path %t/rdar79564324_other.swiftmodule -dump-requirement-machine 2>&1 | %FileCheck %s
+// RUN: %target-swift-frontend -emit-silgen %s -I %t
 
 import rdar79564324_other
 
diff --git a/test/Generics/recursive_conformances.swift b/test/Generics/recursive_conformances.swift
index 391343baa48c4..9f527d53aed1c 100644
--- a/test/Generics/recursive_conformances.swift
+++ b/test/Generics/recursive_conformances.swift
@@ -1,4 +1,4 @@
-// RUN: %target-typecheck-verify-swift -requirement-machine=verify
+// RUN: %target-typecheck-verify-swift
 
 // Make sure the requirement machine can compute a confluent
 // completion in examples where we merge two associated types
diff --git a/test/Generics/unify_associated_types.swift b/test/Generics/unify_associated_types.swift
index 029ae439d7aaa..b3f37ac4eb179 100644
--- a/test/Generics/unify_associated_types.swift
+++ b/test/Generics/unify_associated_types.swift
@@ -1,4 +1,4 @@
-// RUN: %target-typecheck-verify-swift -requirement-machine=verify -dump-requirement-machine 2>&1 | %FileCheck %s
+// RUN: %target-typecheck-verify-swift -dump-requirement-machine 2>&1 | %FileCheck %s
 
 struct Foo<A, B> {}
 
diff --git a/test/Generics/unify_concrete_types_1.swift b/test/Generics/unify_concrete_types_1.swift
index 031c76fa33de7..a0c7335516bbe 100644
--- a/test/Generics/unify_concrete_types_1.swift
+++ b/test/Generics/unify_concrete_types_1.swift
@@ -1,4 +1,4 @@
-// RUN: %target-typecheck-verify-swift -requirement-machine=verify -dump-requirement-machine 2>&1 | %FileCheck %s
+// RUN: %target-typecheck-verify-swift -dump-requirement-machine 2>&1 | %FileCheck %s
 
 struct Foo<A, B> {}
 
diff --git a/test/Generics/unify_concrete_types_2.swift b/test/Generics/unify_concrete_types_2.swift
index ce406e844ff71..05c30771ff361 100644
--- a/test/Generics/unify_concrete_types_2.swift
+++ b/test/Generics/unify_concrete_types_2.swift
@@ -1,4 +1,4 @@
-// RUN: %target-typecheck-verify-swift -requirement-machine=verify -dump-requirement-machine 2>&1 | %FileCheck %s
+// RUN: %target-typecheck-verify-swift -dump-requirement-machine 2>&1 | %FileCheck %s
 
 struct Foo<A, B> {}
 
diff --git a/test/Generics/unify_nested_types_1.swift b/test/Generics/unify_nested_types_1.swift
index cd0ed49e5c7b4..b0fdcf861182d 100644
--- a/test/Generics/unify_nested_types_1.swift
+++ b/test/Generics/unify_nested_types_1.swift
@@ -1,4 +1,4 @@
-// RUN: %target-typecheck-verify-swift -requirement-machine=verify -dump-requirement-machine 2>&1 | %FileCheck %s
+// RUN: %target-typecheck-verify-swift -dump-requirement-machine 2>&1 | %FileCheck %s
 
 protocol P1 {
   associatedtype T : P1
diff --git a/test/Generics/unify_nested_types_2.swift b/test/Generics/unify_nested_types_2.swift
index 82704e88f0509..bac29a539b3fb 100644
--- a/test/Generics/unify_nested_types_2.swift
+++ b/test/Generics/unify_nested_types_2.swift
@@ -1,4 +1,4 @@
-// RUN: %target-typecheck-verify-swift -requirement-machine=verify -dump-requirement-machine 2>&1 | %FileCheck %s
+// RUN: %target-typecheck-verify-swift -dump-requirement-machine 2>&1 | %FileCheck %s
 
 protocol P1 {
   associatedtype T : P1
diff --git a/test/Generics/unify_nested_types_3.swift b/test/Generics/unify_nested_types_3.swift
index 0d6227327aea8..437c491a64028 100644
--- a/test/Generics/unify_nested_types_3.swift
+++ b/test/Generics/unify_nested_types_3.swift
@@ -1,4 +1,4 @@
-// RUN: %target-typecheck-verify-swift -requirement-machine=verify -dump-requirement-machine 2>&1 | %FileCheck %s
+// RUN: %target-typecheck-verify-swift -dump-requirement-machine 2>&1 | %FileCheck %s
 
 protocol P1 {
   associatedtype T : P1
diff --git a/test/Generics/unify_nested_types_4.swift b/test/Generics/unify_nested_types_4.swift
index 4e9be83392996..e04241a2faced 100644
--- a/test/Generics/unify_nested_types_4.swift
+++ b/test/Generics/unify_nested_types_4.swift
@@ -1,4 +1,4 @@
-// RUN: %target-typecheck-verify-swift -requirement-machine=verify -dump-requirement-machine 2>&1 | %FileCheck %s
+// RUN: %target-typecheck-verify-swift -dump-requirement-machine 2>&1 | %FileCheck %s
 
 protocol P1 {
   associatedtype A : P1
diff --git a/test/Generics/unify_nested_types_5.swift b/test/Generics/unify_nested_types_5.swift
index 1325e3e3bc642..d192849609382 100644
--- a/test/Generics/unify_nested_types_5.swift
+++ b/test/Generics/unify_nested_types_5.swift
@@ -1,4 +1,4 @@
-// RUN: %target-typecheck-verify-swift -requirement-machine=verify
+// RUN: %target-typecheck-verify-swift
 
 protocol P {
   associatedtype A : P
diff --git a/test/Generics/unify_superclass_types_1.swift b/test/Generics/unify_superclass_types_1.swift
index b54730731e3c3..fa454984dd8e5 100644
--- a/test/Generics/unify_superclass_types_1.swift
+++ b/test/Generics/unify_superclass_types_1.swift
@@ -1,4 +1,4 @@
-// RUN: %target-typecheck-verify-swift -requirement-machine=verify -dump-requirement-machine 2>&1 | %FileCheck %s
+// RUN: %target-typecheck-verify-swift -dump-requirement-machine 2>&1 | %FileCheck %s
 
 class Base {}
 class Derived : Base {
diff --git a/test/Generics/unify_superclass_types_2.swift b/test/Generics/unify_superclass_types_2.swift
index 0f04ee922f748..7f872d1c0f41d 100644
--- a/test/Generics/unify_superclass_types_2.swift
+++ b/test/Generics/unify_superclass_types_2.swift
@@ -1,4 +1,4 @@
-// RUN: %target-typecheck-verify-swift -requirement-machine=on -dump-requirement-machine 2>&1 | %FileCheck %s
+// RUN: %target-typecheck-verify-swift -dump-requirement-machine 2>&1 | %FileCheck %s
 
 // Note: The GSB fails this test, because it doesn't implement unification of
 // superclass type constructor arguments.
diff --git a/test/Generics/unify_superclass_types_3.swift b/test/Generics/unify_superclass_types_3.swift
index 4b5fa3e05930c..d3bcadcbd1c82 100644
--- a/test/Generics/unify_superclass_types_3.swift
+++ b/test/Generics/unify_superclass_types_3.swift
@@ -1,4 +1,4 @@
-// RUN: %target-typecheck-verify-swift -requirement-machine=on -dump-requirement-machine 2>&1 | %FileCheck %s
+// RUN: %target-typecheck-verify-swift -dump-requirement-machine 2>&1 | %FileCheck %s
 
 // Note: The GSB fails this test, because it doesn't implement unification of
 // superclass type constructor arguments.
diff --git a/test/Generics/unify_superclass_types_4.swift b/test/Generics/unify_superclass_types_4.swift
index 7494a807e777b..75f257ff08c5c 100644
--- a/test/Generics/unify_superclass_types_4.swift
+++ b/test/Generics/unify_superclass_types_4.swift
@@ -1,4 +1,4 @@
-// RUN: %target-typecheck-verify-swift -requirement-machine=on -dump-requirement-machine 2>&1 | %FileCheck %s
+// RUN: %target-typecheck-verify-swift -dump-requirement-machine 2>&1 | %FileCheck %s
 
 // Note: The GSB fails this test, because it doesn't implement unification of
 // superclass type constructor arguments.
diff --git a/test/IRGen/retroactive_conformance_path.swift b/test/IRGen/retroactive_conformance_path.swift
index 1fc7f0bd223b2..3c596cc1f08a5 100644
--- a/test/IRGen/retroactive_conformance_path.swift
+++ b/test/IRGen/retroactive_conformance_path.swift
@@ -1,5 +1,5 @@
 // RUN: %empty-directory(%t) 
-// RUN: %target-build-swift -module-name=test %s -o %t/a.out -requirement-machine=verify
+// RUN: %target-build-swift -module-name=test %s -o %t/a.out
 // RUN: %target-run %t/a.out | %FileCheck %s
 // REQUIRES: executable_test
 // REQUIRES: CPU=arm64 || CPU=x86_64
diff --git a/test/IRGen/retroactive_conformance_path_2.swift b/test/IRGen/retroactive_conformance_path_2.swift
index 44ef7f846278f..9fb81bf680345 100644
--- a/test/IRGen/retroactive_conformance_path_2.swift
+++ b/test/IRGen/retroactive_conformance_path_2.swift
@@ -1,4 +1,4 @@
-// RUN: %target-swift-frontend -emit-ir -g -primary-file %s -requirement-machine=verify
+// RUN: %target-swift-frontend -emit-ir -g -primary-file %s
 
 public struct TestType<T: Error> { }
 
diff --git a/test/SILGen/mangle_conformance_access_path.swift b/test/SILGen/mangle_conformance_access_path.swift
index d8168f9c641a5..2945ed8f55f38 100644
--- a/test/SILGen/mangle_conformance_access_path.swift
+++ b/test/SILGen/mangle_conformance_access_path.swift
@@ -1,6 +1,6 @@
 // RUN: %empty-directory(%t)
 // RUN: %target-swift-frontend -emit-module %S/Inputs/mangle_conformance_access_path_helper.swift -emit-module-path %t/mangle_conformance_access_path_helper.swiftmodule
-// RUN: %target-swift-frontend -emit-silgen %s -I %t -requirement-machine=verify | %FileCheck %s
+// RUN: %target-swift-frontend -emit-silgen %s -I %t | %FileCheck %s
 
 import mangle_conformance_access_path_helper
 
diff --git a/test/SILGen/sil_verifier_method_self_type.swift b/test/SILGen/sil_verifier_method_self_type.swift
index 173302307edb0..526c37fbcfbc1 100644
--- a/test/SILGen/sil_verifier_method_self_type.swift
+++ b/test/SILGen/sil_verifier_method_self_type.swift
@@ -1,4 +1,4 @@
-// RUN: %target-swift-emit-silgen %s -requirement-machine=verify
+// RUN: %target-swift-emit-silgen %s
 
 public class C<Key, Value> {
   public func method() -> Value { fatalError() }
diff --git a/test/SILGen/type_lowering_subst_function_type_conditional_conformance.swift b/test/SILGen/type_lowering_subst_function_type_conditional_conformance.swift
index 9f96871a95689..89ca825b02fbb 100644
--- a/test/SILGen/type_lowering_subst_function_type_conditional_conformance.swift
+++ b/test/SILGen/type_lowering_subst_function_type_conditional_conformance.swift
@@ -1,4 +1,4 @@
-// RUN: %target-swift-emit-silgen %s -requirement-machine=verify | %FileCheck %s
+// RUN: %target-swift-emit-silgen %s | %FileCheck %s
 
 enum E<T : P> {
   case a(T.X)
diff --git a/test/attr/attr_override.swift b/test/attr/attr_override.swift
index cec2a90967ee9..d57e0538b8046 100644
--- a/test/attr/attr_override.swift
+++ b/test/attr/attr_override.swift
@@ -1,4 +1,4 @@
-// RUN: %target-typecheck-verify-swift -swift-version 5 -requirement-machine=verify
+// RUN: %target-typecheck-verify-swift -swift-version 5
 
 @override // expected-error {{'override' can only be specified on class members}} {{1-11=}} expected-error {{'override' is a declaration modifier, not an attribute}} {{1-2=}}
 func virtualAttributeCanNotBeUsedInSource() {}
diff --git a/tools/sil-opt/SILOpt.cpp b/tools/sil-opt/SILOpt.cpp
index 40754d11b4c15..302024875c1c5 100644
--- a/tools/sil-opt/SILOpt.cpp
+++ b/tools/sil-opt/SILOpt.cpp
@@ -458,11 +458,6 @@ static llvm::cl::opt<bool>
                        llvm::cl::desc("Ignore [always_inline] attribute."),
                        llvm::cl::init(false));
 
-static llvm::cl::opt<std::string> EnableRequirementMachine(
-    "requirement-machine",
-    llvm::cl::desc("Control usage of experimental generics implementation: "
-                   "'on', 'off', or 'verify'."));
-
 static void runCommandLineSelectedPasses(SILModule *Module,
                                          irgen::IRGenModule *IRGenMod) {
   const SILOptions &opts = Module->getOptions();
@@ -582,23 +577,6 @@ int main(int argc, char **argv) {
   Invocation.getDiagnosticOptions().VerifyMode =
       VerifyMode ? DiagnosticOptions::Verify : DiagnosticOptions::NoVerify;
 
-  if (EnableRequirementMachine.size()) {
-    auto value = llvm::StringSwitch<Optional<RequirementMachineMode>>(
-        EnableRequirementMachine)
-      .Case("off", RequirementMachineMode::Disabled)
-      .Case("on", RequirementMachineMode::Enabled)
-      .Case("verify", RequirementMachineMode::Verify)
-      .Default(None);
-
-    if (value)
-      Invocation.getLangOptions().EnableRequirementMachine = *value;
-    else {
-      fprintf(stderr, "Invalid value for -requirement-machine flag: %s\n",
-              EnableRequirementMachine.c_str());
-      exit(-1);
-    }
-  }
-
   // Setup the SIL Options.
   SILOptions &SILOpts = Invocation.getSILOptions();
   SILOpts.InlineThreshold = SILInlineThreshold;
diff --git a/validation-test/compiler_crashers_2_fixed/0022-rdar21625478.swift b/validation-test/compiler_crashers_2_fixed/0022-rdar21625478.swift
index be4fda9ff0e61..ac1e3b214aeb9 100644
--- a/validation-test/compiler_crashers_2_fixed/0022-rdar21625478.swift
+++ b/validation-test/compiler_crashers_2_fixed/0022-rdar21625478.swift
@@ -1,6 +1,7 @@
-// RUN: %target-swift-frontend %s -emit-silgen -requirement-machine=off
+// RUN: %target-swift-frontend %s -emit-silgen
 
 // rdar://80395274 tracks getting this to pass with the requirement machine.
+// XFAIL: *
 
 import StdlibUnittest