Index: llvm/include/llvm/ADT/Sequence.h
===================================================================
--- llvm/include/llvm/ADT/Sequence.h
+++ llvm/include/llvm/ADT/Sequence.h
@@ -24,6 +24,30 @@
 
 namespace llvm {
 
+template <typename EnumT> struct iterable_enum_traits {
+  static constexpr bool is_iterable = true;
+};
+
+template <typename EnumT, typename TraitsT> struct enum_with_traits {
+  EnumT value;
+  static constexpr bool is_iterable = TraitsT::is_iterable;
+  using enum_type = EnumT;
+  using underlying_type = std::underlying_type_t<EnumT>;
+};
+
+template <typename EnumT> auto add_enum_traits(EnumT value);
+
+template <typename EnumT>
+enum_with_traits<EnumT, iterable_enum_traits<EnumT>>
+make_iterable_enum(EnumT value) {
+  return {value};
+}
+
+#define DECLARE_ITERABLE_ENUM(ENUM)                                            \
+  inline auto add_enum_traits(ENUM value) {                                    \
+    return llvm::make_iterable_enum(value);                                    \
+  }
+
 namespace detail {
 
 // Returns whether a value of type U can be represented with type T.
@@ -220,8 +244,20 @@
 /// Note: Begin and End values have to be within [INTMAX_MIN, INTMAX_MAX] for
 /// forward iteration (resp. [INTMAX_MIN + 1, INTMAX_MAX] for reverse
 /// iteration).
-template <typename T> auto seq(T Begin, T End) {
-  return iota_range<T>(Begin, End, false);
+template <typename Integral, typename std::enable_if_t<
+  std::is_integral<Integral>::value, bool> = 0>
+auto seq(Integral Begin, Integral End) {
+  return iota_range<Integral>(Begin, End, false);
+}
+
+template <typename ET, typename Traits> auto seq(enum_with_traits<ET, Traits> Begin, enum_with_traits<ET, Traits> End) {
+  return iota_range<ET>(Begin.value, End.value, false);
+}
+
+template <typename Enum, typename std::enable_if_t<
+  std::is_enum<Enum>::value, bool> = 0>
+auto seq(Enum Begin, Enum End) {
+  return seq(add_enum_traits(Begin), add_enum_traits(End));
 }
 
 /// Iterate over an integral/enum type from Begin to End inclusive.
@@ -230,8 +266,23 @@
 /// Note: Begin and End values have to be within [INTMAX_MIN, INTMAX_MAX - 1]
 /// for forward iteration (resp. [INTMAX_MIN + 1, INTMAX_MAX - 1] for reverse
 /// iteration).
-template <typename T> auto seq_inclusive(T Begin, T End) {
-  return iota_range<T>(Begin, End, true);
+
+template <typename Integral, typename std::enable_if_t<
+  std::is_integral<Integral>::value, bool> = 0>
+auto seq_inclusive(Integral Begin, Integral End) {
+  return iota_range<Integral>(Begin, End, true);
+}
+
+template <typename ET, typename Traits>
+auto seq_inclusive(enum_with_traits<ET, Traits> Begin,
+                   enum_with_traits<ET, Traits> End) {
+  return iota_range<ET>(Begin.value, End.value, true);
+}
+
+template <typename Enum,
+          typename std::enable_if_t<std::is_enum<Enum>::value, bool> = 0>
+auto seq_inclusive(Enum Begin, Enum End) {
+  return seq_inclusive(add_enum_traits(Begin), add_enum_traits(End));
 }
 
 } // end namespace llvm
Index: llvm/include/llvm/IR/InstrTypes.h
===================================================================
--- llvm/include/llvm/IR/InstrTypes.h
+++ llvm/include/llvm/IR/InstrTypes.h
@@ -19,6 +19,7 @@
 #include "llvm/ADT/None.h"
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/Sequence.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/Twine.h"
@@ -2357,6 +2358,8 @@
 
 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(FuncletPadInst, Value)
 
+DECLARE_ITERABLE_ENUM(CmpInst::Predicate)
+
 } // end namespace llvm
 
 #endif // LLVM_IR_INSTRTYPES_H
Index: llvm/include/llvm/Support/MachineValueType.h
===================================================================
--- llvm/include/llvm/Support/MachineValueType.h
+++ llvm/include/llvm/Support/MachineValueType.h
@@ -1402,6 +1402,9 @@
     static MVT getVT(Type *Ty, bool HandleUnknown = false);
 
   public:
+
+    friend DECLARE_ITERABLE_ENUM(MVT::SimpleValueType)
+
     /// SimpleValueType Iteration
     /// @{
     static auto all_valuetypes() {
Index: llvm/tools/llvm-exegesis/lib/X86/Target.cpp
===================================================================
--- llvm/tools/llvm-exegesis/lib/X86/Target.cpp
+++ llvm/tools/llvm-exegesis/lib/X86/Target.cpp
@@ -33,6 +33,9 @@
 #endif
 
 namespace llvm {
+
+// DECLARE_ITERABLE_ENUM(X86::CondCode);
+
 namespace exegesis {
 
 static cl::OptionCategory
@@ -619,13 +622,13 @@
 public:
   X86SavedState() {
 #ifdef __x86_64__
-# if defined(_MSC_VER)
+#if defined(_MSC_VER)
     _fxsave64(FPState);
     Eflags = __readeflags();
-# elif defined(__GNUC__)
+#elif defined(__GNUC__)
     __builtin_ia32_fxsave64(FPState);
     Eflags = __builtin_ia32_readeflags_u64();
-# endif
+#endif
 #else
     llvm_unreachable("X86 exegesis running on non-X86 target");
 #endif
@@ -635,15 +638,15 @@
     // Restoring the X87 state does not flush pending exceptions, make sure
     // these exceptions are flushed now.
 #ifdef __x86_64__
-# if defined(_MSC_VER)
+#if defined(_MSC_VER)
     _clearfp();
     _fxrstor64(FPState);
     __writeeflags(Eflags);
-# elif defined(__GNUC__)
+#elif defined(__GNUC__)
     asm volatile("fwait");
     __builtin_ia32_fxrstor64(FPState);
     __builtin_ia32_writeeflags_u64(Eflags);
-# endif
+#endif
 #else
     llvm_unreachable("X86 exegesis running on non-X86 target");
 #endif
@@ -919,7 +922,7 @@
     case X86::OperandType::OPERAND_COND_CODE: {
       Exploration = true;
       auto CondCodes =
-          seq_inclusive(X86::CondCode::COND_O, X86::CondCode::LAST_VALID_COND);
+          seq_inclusive(make_iterable_enum(X86::CondCode::COND_O), make_iterable_enum(X86::CondCode::LAST_VALID_COND));
       Choices.reserve(CondCodes.size());
       for (int CondCode : CondCodes)
         Choices.emplace_back(MCOperand::createImm(CondCode));
Index: llvm/unittests/ADT/SequenceTest.cpp
===================================================================
--- llvm/unittests/ADT/SequenceTest.cpp
+++ llvm/unittests/ADT/SequenceTest.cpp
@@ -68,17 +68,6 @@
   EXPECT_EQ(Actual - (Actual + 2), -2);
 }
 
-TEST(StrongIntTest, Enums) {
-  enum UntypedEnum { A = 3 };
-  EXPECT_EQ(CheckedInt::from(A).to<UntypedEnum>(), A);
-
-  enum TypedEnum : uint32_t { B = 3 };
-  EXPECT_EQ(CheckedInt::from(B).to<TypedEnum>(), B);
-
-  enum class ScopedEnum : uint16_t { C = 3 };
-  EXPECT_EQ(CheckedInt::from(ScopedEnum::C).to<ScopedEnum>(), ScopedEnum::C);
-}
-
 #if defined(GTEST_HAS_DEATH_TEST) && !defined(NDEBUG)
 TEST(StrongIntDeathTest, OutOfBounds) {
   // Values above 'INTMAX_MAX' are not representable.
@@ -215,4 +204,28 @@
   EXPECT_EQ(Backward[2], 7);
 }
 
-} // anonymous namespace
+enum UntypedEnum { A = 3 };
+enum TypedEnum : uint32_t { B = 3 };
+
+DECLARE_ITERABLE_ENUM(UntypedEnum)
+DECLARE_ITERABLE_ENUM(TypedEnum)
+
+namespace X {
+enum class ScopedEnum : uint16_t { C = 3 };
+DECLARE_ITERABLE_ENUM(X::ScopedEnum)
+} // namespace X
+
+enum class ScopedEnum2 : uint16_t { C = 3 };
+
+TEST(StrongIntTest, Enums) {
+  EXPECT_EQ(CheckedInt::from(A).to<UntypedEnum>(), A);
+  EXPECT_EQ(CheckedInt::from(B).to<TypedEnum>(), B);
+  EXPECT_EQ(CheckedInt::from(X::ScopedEnum::C).to<X::ScopedEnum>(), X::ScopedEnum::C);
+}
+
+TEST(StrongIntTest, EnumEscapeHatch) {
+  EXPECT_FALSE(llvm::empty(seq_inclusive(X::ScopedEnum::C, X::ScopedEnum::C)));
+  EXPECT_FALSE(llvm::empty(seq_inclusive(make_iterable_enum(ScopedEnum2::C),
+                                         make_iterable_enum(ScopedEnum2::C))));
+}
+} // namespace