[SYCL] Fix nightly CTS failure after e7defab (#14164)

Failure:
https://github.com/intel/llvm/actions/runs/9493008325/job/26161455039

Author: uditagarwal97

sycl/include/sycl/vector_preview.hpp

@@ -1031,15 +1031,15 @@ class SwizzleOp {
   SwizzleOp &operator=(const vec<DataT, IdxNum> &Rhs) {
     std::array<int, IdxNum> Idxs{Indexes...};
     for (size_t I = 0; I < Idxs.size(); ++I) {
-      m_Vector[Idxs[I]] = Rhs.getValue(I);
+      (*m_Vector)[Idxs[I]] = Rhs.getValue(I);
     }
     return *this;
   }
 
   template <int IdxNum = getNumElements(), typename = EnableIfOneIndex<IdxNum>>
   SwizzleOp &operator=(const DataT &Rhs) {
     std::array<int, IdxNum> Idxs{Indexes...};
-    m_Vector[Idxs[0]] = Rhs;
+    (*m_Vector)[Idxs[0]] = Rhs;
     return *this;
   }
 
@@ -1048,15 +1048,15 @@ class SwizzleOp {
   SwizzleOp &operator=(const DataT &Rhs) {
     std::array<int, IdxNum> Idxs{Indexes...};
     for (auto Idx : Idxs) {
-      m_Vector[Idx] = Rhs;
+      (*m_Vector)[Idx] = Rhs;
     }
     return *this;
   }
 
   template <int IdxNum = getNumElements(), typename = EnableIfOneIndex<IdxNum>>
   SwizzleOp &operator=(DataT &&Rhs) {
     std::array<int, IdxNum> Idxs{Indexes...};
-    m_Vector[Idxs[0]] = Rhs;
+    (*m_Vector)[Idxs[0]] = Rhs;
     return *this;
   }
 
@@ -1209,7 +1209,7 @@ class SwizzleOp {
   SwizzleOp &operator=(const SwizzleOp<T1, T2, T3, T4, T5...> &Rhs) {
     std::array<int, getNumElements()> Idxs{Indexes...};
     for (size_t I = 0; I < Idxs.size(); ++I) {
-      m_Vector[Idxs[I]] = Rhs.getValue(I);
+      (*m_Vector)[Idxs[I]] = Rhs.getValue(I);
     }
     return *this;
   }
@@ -1221,7 +1221,7 @@ class SwizzleOp {
   SwizzleOp &operator=(SwizzleOp<T1, T2, T3, T4, T5...> &&Rhs) {
     std::array<int, getNumElements()> Idxs{Indexes...};
     for (size_t I = 0; I < Idxs.size(); ++I) {
-      m_Vector[Idxs[I]] = Rhs.getValue(I);
+      (*m_Vector)[Idxs[I]] = Rhs.getValue(I);
     }
     return *this;
   }
@@ -1436,7 +1436,7 @@ class SwizzleOp {
     std::array<int, getNumElements()> Idxs{Indexes...};
     for (size_t I = 0; I < Idxs.size(); ++I) {
       DataT Res = Op(m_Vector->getValue(Idxs[I]), Rhs.getValue(I));
-      m_Vector[Idxs[I]] = Res;
+      (*m_Vector)[Idxs[I]] = Res;
     }
   }
 

sycl/test/basic_tests/vectors/vectors.cpp

@@ -168,6 +168,26 @@ int main() {
   assert((!inputVec4.lo().as<sycl::vec<bool, 2>>()[0]));
   assert((inputVec4.lo().as<sycl::vec<bool, 2>>()[1]));
 
+  // Check assignment operator for swizzles.
+  {
+    sycl::vec<int8_t, 2> inputVec1 = sycl::vec<int8_t, 2>(0, 1);
+    sycl::vec<int8_t, 2> inputVec2 = sycl::vec<int8_t, 2>(2, 3);
+    auto swiz1 = inputVec1.template swizzle<sycl::elem::s1, sycl::elem::s0>();
+    auto swiz2 = inputVec2.template swizzle<sycl::elem::s0, sycl::elem::s1>();
+
+    // Assign swizzle to swizzle.
+    swiz1 = swiz2;
+    assert(inputVec1[0] == 3 && inputVec1[1] == 2);
+
+    // Assign vec to swizzle.
+    swiz1 = sycl::vec<int8_t, 2>(0, 1);
+    assert(inputVec1[0] == 1 && inputVec1[1] == 0);
+
+    // Assign single element to swizzle.
+    swiz1 = (int8_t)5;
+    assert(inputVec1[0] == 5 && inputVec1[1] == 5);
+  }
+
   // Check that [u]long[n] type aliases match vec<[u]int64_t, n> types.
   assert((std::is_same<sycl::vec<std::int64_t, 2>, sycl::long2>::value));
   assert((std::is_same<sycl::vec<std::int64_t, 3>, sycl::long3>::value));