[SYCL] Fix operators for bool swizzled vec

sycl/include/sycl/types.hpp

@@ -1544,8 +1544,37 @@ template <typename VecT, typename OperationLeftT, typename OperationRightT,
           template <typename> class OperationCurrentT, int... Indexes>
 class SwizzleOp {
   using DataT = typename VecT::element_type;
-  using CommonDataT = std::common_type_t<typename OperationLeftT::DataT,
-                                         typename OperationRightT::DataT>;
+  // Certain operators return a vector with a different element type. Also, the
+  // left and right operand types may differ. CommonDataT selects a result type
+  // based on these types to ensure that the result value can be represented.
+  //
+  // Example 1:
+  //   sycl::vec<unsigned char, 4> vec{...};
+  //   auto result = 300u + vec.x();
+  //
+  // CommonDataT is std::common_type_t<OperationLeftT, OperationRightT> since
+  // it's larger than unsigned char.
+  //
+  // Example 2:
+  //   sycl::vec<bool, 1> vec{...};
+  //   auto result = vec.template swizzle<sycl::elem::s0>() && vec;
+  //
+  // CommonDataT is DataT since operator&& returns a vector with element type
+  // int8_t, which is larger than bool.
+  //
+  // Example 3:
+  //   sycl::vec<std::byte, 4> vec{...}; auto swlo = vec.lo();
+  //   auto result = swlo == swlo;
+  //
+  // CommonDataT is DataT since operator== returns a vector with element type
+  // int8_t, which is the same size as std::byte. std::common_type_t<DataT, ...>
+  // can't be used here since there's no type that int8_t and std::byte can both
+  // be implicitly converted to.
+  using OpLeftDataT = typename OperationLeftT::DataT;
+  using OpRightDataT = typename OperationRightT::DataT;
+  using CommonDataT = std::conditional_t<
+      sizeof(DataT) >= sizeof(std::common_type_t<OpLeftDataT, OpRightDataT>),
+      DataT, std::common_type_t<OpLeftDataT, OpRightDataT>>;
   static constexpr int getNumElements() { return sizeof...(Indexes); }
 
   using rel_t = detail::rel_t<DataT>;

sycl/test-e2e/Regression/vec_rel_swizzle_ops.cpp

@@ -0,0 +1,68 @@
+// RUN: %{build} -o %t.out
+// RUN: %{run} %t.out
+
+// RUN: %if preview-breaking-changes-supported %{ %clangxx -fsycl -fpreview-breaking-changes %s -o %t2.out %}
+// RUN: %if preview-breaking-changes-supported %{ %{run} %t2.out %}
+
+#include <cstdlib>
+#include <sycl/sycl.hpp>
+
+template <typename T, typename ResultT>
+bool testAndOperator(const std::string &typeName) {
+  constexpr int N = 5;
+  std::array<ResultT, N> results{};
+
+  sycl::queue q;
+  sycl::buffer<ResultT, 1> buffer{results.data(), N};
+  q.submit([&](sycl::handler &cgh) {
+     sycl::accessor acc{buffer, cgh, sycl::write_only};
+     cgh.parallel_for(sycl::range<1>{1}, [=](sycl::id<1> id) {
+       auto testVec1 = sycl::vec<T, 1>(static_cast<T>(1));
+       auto testVec2 = sycl::vec<T, 1>(static_cast<T>(2));
+       sycl::vec<ResultT, 1> resVec;
+
+       ResultT expected = static_cast<ResultT>(
+           -(static_cast<ResultT>(1) && static_cast<ResultT>(2)));
+       acc[0] = expected;
+
+       // LHS swizzle
+       resVec = testVec1.template swizzle<sycl::elem::s0>() && testVec2;
+       acc[1] = resVec[0];
+
+       // RHS swizzle
+       resVec = testVec1 && testVec2.template swizzle<sycl::elem::s0>();
+       acc[2] = resVec[0];
+
+       // No swizzle
+       resVec = testVec1 && testVec2;
+       acc[3] = resVec[0];
+
+       // Both swizzle
+       resVec = testVec1.template swizzle<sycl::elem::s0>() &&
+                testVec2.template swizzle<sycl::elem::s0>();
+       acc[4] = resVec[0];
+     });
+   }).wait();
+
+  bool passed = true;
+  ResultT expected = results[0];
+
+  std::cout << "Testing with T = " << typeName << std::endl;
+  std::cout << "Expected: " << (int)expected << std::endl;
+  for (int i = 1; i < N; i++) {
+    std::cout << "Test " << (i - 1) << ": " << ((int)results[i]) << std::endl;
+    passed &= expected == results[i];
+  }
+  std::cout << std::endl;
+  return passed;
+}
+
+int main() {
+  bool passed = true;
+  passed &= testAndOperator<bool, std::int8_t>("bool");
+  passed &= testAndOperator<std::int8_t, std::int8_t>("std::int8_t");
+  passed &= testAndOperator<float, std::int32_t>("float");
+  passed &= testAndOperator<int, std::int32_t>("int");
+  std::cout << (passed ? "Pass" : "Fail") << std::endl;
+  return (passed ? EXIT_SUCCESS : EXIT_FAILURE);
+}