diff --git a/sycl/include/sycl/detail/vector_arith.hpp b/sycl/include/sycl/detail/vector_arith.hpp
index 0b24c71454984..6d92213e825e5 100644
--- a/sycl/include/sycl/detail/vector_arith.hpp
+++ b/sycl/include/sycl/detail/vector_arith.hpp
@@ -66,6 +66,18 @@ struct IncDec {};
 
 template <class T> static constexpr bool not_fp = !is_vgenfloat_v<T>;
 
+#if !__SYCL_USE_LIBSYCL8_VEC_IMPL
+// Not using `is_byte_v` to avoid unnecessary dependencies on `half`/`bfloat16`
+// headers.
+template <class T>
+static constexpr bool not_byte =
+#if (!defined(_HAS_STD_BYTE) || _HAS_STD_BYTE != 0)
+    !std::is_same_v<T, std::byte>;
+#else
+    true;
+#endif
+#endif
+
 // To provide information about operators availability depending on vec/swizzle
 // element type.
 template <typename Op, typename T>
@@ -80,6 +92,7 @@ inline constexpr bool is_op_available_for_type<OpAssign<Op>, T> =
   inline constexpr bool is_op_available_for_type<OP, T> = COND;
 
 // clang-format off
+#if __SYCL_USE_LIBSYCL8_VEC_IMPL
 __SYCL_OP_AVAILABILITY(std::plus<void>          , true)
 __SYCL_OP_AVAILABILITY(std::minus<void>         , true)
 __SYCL_OP_AVAILABILITY(std::multiplies<void>    , true)
@@ -110,6 +123,38 @@ __SYCL_OP_AVAILABILITY(std::bit_not<void>       , not_fp<T>)
 __SYCL_OP_AVAILABILITY(UnaryPlus                , true)
 
 __SYCL_OP_AVAILABILITY(IncDec                   , true)
+#else
+__SYCL_OP_AVAILABILITY(std::plus<void>          , not_byte<T>)
+__SYCL_OP_AVAILABILITY(std::minus<void>         , not_byte<T>)
+__SYCL_OP_AVAILABILITY(std::multiplies<void>    , not_byte<T>)
+__SYCL_OP_AVAILABILITY(std::divides<void>       , not_byte<T>)
+__SYCL_OP_AVAILABILITY(std::modulus<void>       , not_fp<T>)
+
+__SYCL_OP_AVAILABILITY(std::bit_and<void>       , not_fp<T>)
+__SYCL_OP_AVAILABILITY(std::bit_or<void>        , not_fp<T>)
+__SYCL_OP_AVAILABILITY(std::bit_xor<void>       , not_fp<T>)
+
+__SYCL_OP_AVAILABILITY(std::equal_to<void>      , true)
+__SYCL_OP_AVAILABILITY(std::not_equal_to<void>  , true)
+__SYCL_OP_AVAILABILITY(std::less<void>          , true)
+__SYCL_OP_AVAILABILITY(std::greater<void>       , true)
+__SYCL_OP_AVAILABILITY(std::less_equal<void>    , true)
+__SYCL_OP_AVAILABILITY(std::greater_equal<void> , true)
+
+__SYCL_OP_AVAILABILITY(std::logical_and<void>   , not_byte<T> && not_fp<T>)
+__SYCL_OP_AVAILABILITY(std::logical_or<void>    , not_byte<T> && not_fp<T>)
+
+__SYCL_OP_AVAILABILITY(ShiftLeft                , not_byte<T> && not_fp<T>)
+__SYCL_OP_AVAILABILITY(ShiftRight               , not_byte<T> && not_fp<T>)
+
+// Unary
+__SYCL_OP_AVAILABILITY(std::negate<void>        , not_byte<T>)
+__SYCL_OP_AVAILABILITY(std::logical_not<void>   , not_byte<T>)
+__SYCL_OP_AVAILABILITY(std::bit_not<void>       , not_fp<T>)
+__SYCL_OP_AVAILABILITY(UnaryPlus                , not_byte<T>)
+
+__SYCL_OP_AVAILABILITY(IncDec                   , not_byte<T>)
+#endif
 // clang-format on
 
 #undef __SYCL_OP_AVAILABILITY
@@ -188,6 +233,12 @@ template <typename Self> struct VecOperators {
   using element_type = typename from_incomplete<Self>::element_type;
   static constexpr int N = from_incomplete<Self>::size();
 
+#if !__SYCL_USE_LIBSYCL8_VEC_IMPL
+  template <typename T>
+  static constexpr bool is_compatible_scalar =
+      std::is_convertible_v<T, typename from_incomplete<Self>::element_type>;
+#endif
+
   template <typename Op>
   using result_t = std::conditional_t<
       is_logical<Op>, vec<fixed_width_signed<sizeof(element_type)>, N>, Self>;
@@ -293,6 +344,7 @@ template <typename Self> struct VecOperators {
   struct OpMixin<Op, std::enable_if_t<std::is_same_v<Op, IncDec>>>
       : public IncDecImpl<Self> {};
 
+#if __SYCL_USE_LIBSYCL8_VEC_IMPL
 #define __SYCL_VEC_BINOP_MIXIN(OP, OPERATOR)                                   \
   template <typename Op>                                                       \
   struct OpMixin<Op, std::enable_if_t<std::is_same_v<Op, OP>>> {               \
@@ -341,6 +393,52 @@ template <typename Self> struct VecOperators {
     friend auto operator OPERATOR(const Self &v) { return apply<OP>(v); }      \
   };
 
+#else
+
+#define __SYCL_VEC_BINOP_MIXIN(OP, OPERATOR)                                   \
+  template <typename Op>                                                       \
+  struct OpMixin<Op, std::enable_if_t<std::is_same_v<Op, OP>>> {               \
+    friend result_t<OP> operator OPERATOR(const Self & lhs,                    \
+                                          const Self & rhs) {                  \
+      return VecOperators::apply<OP>(lhs, rhs);                                \
+    }                                                                          \
+    template <typename T>                                                      \
+    friend std::enable_if_t<is_compatible_scalar<T>, result_t<OP>>             \
+    operator OPERATOR(const Self & lhs, const T & rhs) {                       \
+      return VecOperators::apply<OP>(lhs, Self{static_cast<T>(rhs)});          \
+    }                                                                          \
+    template <typename T>                                                      \
+    friend std::enable_if_t<is_compatible_scalar<T>, result_t<OP>>             \
+    operator OPERATOR(const T & lhs, const Self & rhs) {                       \
+      return VecOperators::apply<OP>(Self{static_cast<T>(lhs)}, rhs);          \
+    }                                                                          \
+  };
+
+#define __SYCL_VEC_OPASSIGN_MIXIN(OP, OPERATOR)                                \
+  template <typename Op>                                                       \
+  struct OpMixin<Op, std::enable_if_t<std::is_same_v<Op, OpAssign<OP>>>> {     \
+    friend Self &operator OPERATOR(Self & lhs, const Self & rhs) {             \
+      lhs = OP{}(lhs, rhs);                                                    \
+      return lhs;                                                              \
+    }                                                                          \
+    template <typename T>                                                      \
+    friend std::enable_if_t<is_compatible_scalar<T>, Self &>                   \
+    operator OPERATOR(Self & lhs, const T & rhs) {                             \
+      lhs = OP{}(lhs, rhs);                                                    \
+      return lhs;                                                              \
+    }                                                                          \
+  };
+
+#define __SYCL_VEC_UOP_MIXIN(OP, OPERATOR)                                     \
+  template <typename Op>                                                       \
+  struct OpMixin<Op, std::enable_if_t<std::is_same_v<Op, OP>>> {               \
+    friend result_t<OP> operator OPERATOR(const Self & v) {                    \
+      return apply<OP>(v);                                                     \
+    }                                                                          \
+  };
+
+#endif
+
   __SYCL_INSTANTIATE_OPERATORS(__SYCL_VEC_BINOP_MIXIN,
                                __SYCL_VEC_OPASSIGN_MIXIN, __SYCL_VEC_UOP_MIXIN)
 
@@ -348,6 +446,7 @@ template <typename Self> struct VecOperators {
 #undef __SYCL_VEC_OPASSIGN_MIXIN
 #undef __SYCL_VEC_BINOP_MIXIN
 
+#if __SYCL_USE_LIBSYCL8_VEC_IMPL
   template <typename Op>
   struct OpMixin<Op, std::enable_if_t<std::is_same_v<Op, std::bit_not<void>>>> {
     template <typename T = typename from_incomplete<Self>::element_type>
@@ -356,6 +455,7 @@ template <typename Self> struct VecOperators {
       return apply<std::bit_not<void>>(v);
     }
   };
+#endif
 
   template <typename... Op>
   struct __SYCL_EBO CombineImpl : public OpMixin<Op>... {};
@@ -377,6 +477,7 @@ template <typename Self> struct VecOperators {
                     OpAssign<ShiftRight>, IncDec> {};
 };
 
+#if __SYCL_USE_LIBSYCL8_VEC_IMPL
 template <typename DataT, int NumElements>
 class vec_arith : public VecOperators<vec<DataT, NumElements>>::Combined {};
 
@@ -427,6 +528,7 @@ class vec_arith<std::byte, NumElements>
   }
 };
 #endif // (!defined(_HAS_STD_BYTE) || _HAS_STD_BYTE != 0)
+#endif
 
 #undef __SYCL_INSTANTIATE_OPERATORS
 
diff --git a/sycl/include/sycl/vector.hpp b/sycl/include/sycl/vector.hpp
index 7dbc453367fcd..556e91e7912ef 100644
--- a/sycl/include/sycl/vector.hpp
+++ b/sycl/include/sycl/vector.hpp
@@ -318,14 +318,18 @@ template <typename DataT> class vec_base<DataT, 1> {
 // Provides a cross-platform vector class template that works efficiently on
 // SYCL devices as well as in host C++ code.
 template <typename DataT, int NumElements>
-class __SYCL_EBO vec
-    : public detail::vec_arith<DataT, NumElements>,
-      public detail::ApplyIf<
-          NumElements == 1,
-          detail::ScalarConversionOperatorsMixIn<vec<DataT, NumElements>>>,
-      public detail::NamedSwizzlesMixinBoth<vec<DataT, NumElements>>,
-      // Keep it last to simplify ABI layout test:
-      public detail::vec_base<DataT, NumElements> {
+class __SYCL_EBO vec :
+#if __SYCL_USE_LIBSYCL8_VEC_IMPL
+    public detail::vec_arith<DataT, NumElements>,
+#else
+    public detail::VecOperators<vec<DataT, NumElements>>::Combined,
+#endif
+    public detail::ApplyIf<
+        NumElements == 1,
+        detail::ScalarConversionOperatorsMixIn<vec<DataT, NumElements>>>,
+    public detail::NamedSwizzlesMixinBoth<vec<DataT, NumElements>>,
+    // Keep it last to simplify ABI layout test:
+    public detail::vec_base<DataT, NumElements> {
   static_assert(std::is_same_v<DataT, std::remove_cv_t<DataT>>,
                 "DataT must be cv-unqualified");
 
@@ -408,6 +412,7 @@ class __SYCL_EBO vec
   constexpr vec &operator=(const vec &) = default;
   constexpr vec &operator=(vec &&) = default;
 
+#if __SYCL_USE_LIBSYCL8_VEC_IMPL
   // Template required to prevent ambiguous overload with the copy assignment
   // when NumElements == 1. The template prevents implicit conversion from
   // vec<_, 1> to DataT.
@@ -427,6 +432,14 @@ class __SYCL_EBO vec
     *this = Rhs.template as<vec>();
     return *this;
   }
+#else
+  template <typename T>
+  typename std::enable_if_t<std::is_convertible_v<T, DataT>, vec &>
+  operator=(const T &Rhs) {
+    *this = vec{static_cast<DataT>(Rhs)};
+    return *this;
+  }
+#endif
 
   __SYCL2020_DEPRECATED("get_count() is deprecated, please use size() instead")
   static constexpr size_t get_count() { return size(); }
@@ -536,8 +549,10 @@ class __SYCL_EBO vec
             int... T5>
   friend class detail::SwizzleOp;
   template <typename T1, int T2> friend class __SYCL_EBO vec;
+#if __SYCL_USE_LIBSYCL8_VEC_IMPL
   // To allow arithmetic operators access private members of vec.
   template <typename T1, int T2> friend class detail::vec_arith;
+#endif
 };
 ///////////////////////// class sycl::vec /////////////////////////
 
diff --git a/sycl/test-e2e/Basic/vector/byte.cpp b/sycl/test-e2e/Basic/vector/byte.cpp
index 6eadf6a177b7b..c2edadf147ed3 100644
--- a/sycl/test-e2e/Basic/vector/byte.cpp
+++ b/sycl/test-e2e/Basic/vector/byte.cpp
@@ -180,6 +180,7 @@ int main() {
       assert(SwizByte2Neg[0] == ~SwizByte2B[0]);
     }
 
+#if __SYCL_USE_LIBSYCL8_VEC_IMPL
     {
       // std::byte is not an arithmetic type and it only supports the following
       // overloads of >> and << operators.
@@ -207,6 +208,7 @@ int main() {
       assert(SwizShiftRight[0] == SwizByte2Shift[0] >> 3 &&
              SwizShiftLeft[1] == SwizByte2Shift[1] << 3);
     }
+#endif
   }
 
   return 0;
diff --git a/sycl/test-e2e/Basic/vector/vec_binary_scalar_order.hpp b/sycl/test-e2e/Basic/vector/vec_binary_scalar_order.hpp
index 879a4f6da9463..1ae7733195728 100644
--- a/sycl/test-e2e/Basic/vector/vec_binary_scalar_order.hpp
+++ b/sycl/test-e2e/Basic/vector/vec_binary_scalar_order.hpp
@@ -38,10 +38,10 @@ bool CheckResult(sycl::vec<T1, N> V, T2 Ref) {
     constexpr T RefVal = 2;                                                    \
     VecT InVec{static_cast<T>(RefVal)};                                        \
     {                                                                          \
-      VecT OutVecsDevice[2];                                                   \
+      ResT OutVecsDevice[2];                                                   \
       T OutRefsDevice[2];                                                      \
       {                                                                        \
-        sycl::buffer<VecT, 1> OutVecsBuff{OutVecsDevice, 2};                   \
+        sycl::buffer<ResT, 1> OutVecsBuff{OutVecsDevice, 2};                   \
         sycl::buffer<T, 1> OutRefsBuff{OutRefsDevice, 2};                      \
         Q.submit([&](sycl::handler &CGH) {                                     \
           sycl::accessor OutVecsAcc{OutVecsBuff, CGH, sycl::read_write};       \
diff --git a/sycl/test-e2e/DeviceLib/built-ins/vector_integer.cpp b/sycl/test-e2e/DeviceLib/built-ins/vector_integer.cpp
index 32afba1e95f07..876f800743769 100644
--- a/sycl/test-e2e/DeviceLib/built-ins/vector_integer.cpp
+++ b/sycl/test-e2e/DeviceLib/built-ins/vector_integer.cpp
@@ -203,9 +203,9 @@ int main() {
 
   // abs
   {
-    s::uint2 r{0};
+    s::int2 r{0};
     {
-      s::buffer<s::uint2, 1> BufR(&r, s::range<1>(1));
+      s::buffer<s::int2, 1> BufR(&r, s::range<1>(1));
       s::queue myQueue;
       myQueue.submit([&](s::handler &cgh) {
         auto AccR = BufR.get_access<s::access::mode::write>(cgh);
@@ -214,8 +214,8 @@ int main() {
         });
       });
     }
-    unsigned int r1 = r.x();
-    unsigned int r2 = r.y();
+    int r1 = r.x();
+    int r2 = r.y();
     assert(r1 == 5);
     assert(r2 == 2);
   }
@@ -240,9 +240,9 @@ int main() {
 
   // abs_diff
   {
-    s::uint2 r{0};
+    s::int2 r{0};
     {
-      s::buffer<s::uint2, 1> BufR(&r, s::range<1>(1));
+      s::buffer<s::int2, 1> BufR(&r, s::range<1>(1));
       s::queue myQueue;
       myQueue.submit([&](s::handler &cgh) {
         auto AccR = BufR.get_access<s::access::mode::write>(cgh);
@@ -251,8 +251,8 @@ int main() {
         });
       });
     }
-    unsigned int r1 = r.x();
-    unsigned int r2 = r.y();
+    int r1 = r.x();
+    int r2 = r.y();
     assert(r1 == 4);
     assert(r2 == 1);
   }
diff --git a/sycl/test/basic_tests/vectors/assign.cpp b/sycl/test/basic_tests/vectors/assign.cpp
index 67ed92971d022..2045eca0303e3 100644
--- a/sycl/test/basic_tests/vectors/assign.cpp
+++ b/sycl/test/basic_tests/vectors/assign.cpp
@@ -27,8 +27,8 @@ using sw_double_2 = decltype(std::declval<vec<double, 4>>().swizzle<1, 2>());
 //            EXCEPT_IN_PREVIEW condition<>
 
 static_assert(                  std::is_assignable_v<vec<half, 1>, half>);
-static_assert(EXCEPT_IN_PREVIEW std::is_assignable_v<vec<half, 1>, float>);
-static_assert(EXCEPT_IN_PREVIEW std::is_assignable_v<vec<half, 1>, double>);
+static_assert(                  std::is_assignable_v<vec<half, 1>, float>);
+static_assert(                  std::is_assignable_v<vec<half, 1>, double>);
 static_assert(                  std::is_assignable_v<vec<half, 1>, vec<half, 1>>);
 static_assert(EXCEPT_IN_PREVIEW std::is_assignable_v<vec<half, 1>, vec<float, 1>>);
 static_assert(EXCEPT_IN_PREVIEW std::is_assignable_v<vec<half, 1>, vec<double, 1>>);