reviewer feedback. restored release note and moved bit_cast to its own file

Signed-off-by: Chris Perkins <[email protected]>

Author: cperkinsintel

sycl/ReleaseNotes.md

@@ -763,7 +763,7 @@ Release notes for the commit range ba404be..24726df
     BEs to perform additional optimizations [fdcaeae] [08f8656]
   - Added partial support for [Host task with interop capabilities extension](https://github.com/codeplaysoftware/standards-proposals/blob/master/host_task/host_task.md) [ae3fd5c]
   - Added support for [SYCL_INTEL_bitcast](doc/extensions/Bitcast/SYCL_INTEL_bitcast.asciidoc)
-    as a `sycl::bit_cast` [e3da4ef]
+    as a `sycl::detail::bit_cast` [e3da4ef]
   - Introduced the Level Zero plugin which enables SYCL working on top of Level0
     API. Interoperability is not supportet yet [d32da99]
   - Implemented [parallel_for simplification extension](doc/extensions/ParallelForSimpification) [13fe9fb]

sycl/include/CL/sycl/bit_cast.hpp

@@ -0,0 +1,54 @@
+//==---------------- helpers.hpp - SYCL helpers ----------------------------==//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#pragma once
+
+#if __cpp_lib_bit_cast
+#include <bit>
+#endif
+
+__SYCL_INLINE_NAMESPACE(cl) {
+namespace sycl {
+
+// forward decl
+namespace detail {
+inline void memcpy(void *Dst, const void *Src, size_t Size);
+}
+
+// sycl::bit_cast ( no longer sycl::detail::bit_cast )
+template <typename To, typename From>
+#if __cpp_lib_bit_cast || __has_builtin(__builtin_bit_cast)
+constexpr
+#endif
+    To
+    bit_cast(const From &from) noexcept {
+  static_assert(sizeof(To) == sizeof(From),
+                "Sizes of To and From must be equal");
+  static_assert(std::is_trivially_copyable<From>::value,
+                "From must be trivially copyable");
+  static_assert(std::is_trivially_copyable<To>::value,
+                "To must be trivially copyable");
+#if __cpp_lib_bit_cast
+  return std::bit_cast<To>(from);
+#else // __cpp_lib_bit_cast
+
+#if __has_builtin(__builtin_bit_cast)
+  return __builtin_bit_cast(To, from);
+#else  // __has_builtin(__builtin_bit_cast)
+  static_assert(std::is_trivially_default_constructible<To>::value,
+                "To must be trivially default constructible");
+  To to;
+  sycl::detail::memcpy(&to, &from, sizeof(To));
+  return to;
+#endif // __has_builtin(__builtin_bit_cast)
+
+#endif // __cpp_lib_bit_cast
+}
+
+} // namespace sycl
+} // __SYCL_INLINE_NAMESPACE(cl)

sycl/include/CL/sycl/detail/helpers.hpp

@@ -245,35 +245,5 @@ getSPIRVMemorySemanticsMask(const access::fence_space AccessSpace,
 
 } // namespace detail
 
-// sycl::bit_cast ( no longer sycl::detail::bit_cast )
-template <typename To, typename From>
-#if __cpp_lib_bit_cast || __has_builtin(__builtin_bit_cast)
-constexpr
-#endif
-    To
-    bit_cast(const From &from) noexcept {
-  static_assert(sizeof(To) == sizeof(From),
-                "Sizes of To and From must be equal");
-  static_assert(std::is_trivially_copyable<From>::value,
-                "From must be trivially copyable");
-  static_assert(std::is_trivially_copyable<To>::value,
-                "To must be trivially copyable");
-#if __cpp_lib_bit_cast
-  return std::bit_cast<To>(from);
-#else // __cpp_lib_bit_cast
-
-#if __has_builtin(__builtin_bit_cast)
-  return __builtin_bit_cast(To, from);
-#else  // __has_builtin(__builtin_bit_cast)
-  static_assert(std::is_trivially_default_constructible<To>::value,
-                "To must be trivially default constructible");
-  To to;
-  sycl::detail::memcpy(&to, &from, sizeof(To));
-  return to;
-#endif // __has_builtin(__builtin_bit_cast)
-
-#endif // __cpp_lib_bit_cast
-}
-
 } // namespace sycl
 } // __SYCL_INLINE_NAMESPACE(cl)

sycl/include/CL/sycl/stl.hpp

@@ -12,6 +12,7 @@
 
 #include <CL/sycl/detail/defines.hpp>
 
+#include "bit_cast.hpp"
 #include <exception>
 #include <functional>
 #include <memory>