[SYCL] Infer IdT in GroupBroadcast from group type (#2115)

- Work-group => any integral type
- Sub-group => unsigned 32-bit integer

Signed-off-by: John Pennycook <[email protected]>

Author: Pennycook

sycl/include/CL/sycl/detail/spirv.hpp

@@ -42,15 +42,29 @@ template <typename Group> bool GroupAny(bool pred) {
 }
 
 // Broadcast with scalar local index
+// Work-group supports any integral type
+// Sub-group currently supports only uint32_t
 template <typename Group, typename T, typename IdT>
-detail::enable_if_t<std::is_integral<IdT>::value, T>
+detail::enable_if_t<is_group<Group>::value && std::is_integral<IdT>::value, T>
 GroupBroadcast(T x, IdT local_id) {
   using OCLT = detail::ConvertToOpenCLType_t<T>;
   using OCLIdT = detail::ConvertToOpenCLType_t<IdT>;
   OCLT ocl_x = detail::convertDataToType<T, OCLT>(x);
   OCLIdT ocl_id = detail::convertDataToType<IdT, OCLIdT>(local_id);
   return __spirv_GroupBroadcast(group_scope<Group>::value, ocl_x, ocl_id);
 }
+template <typename Group, typename T, typename IdT>
+detail::enable_if_t<is_sub_group<Group>::value && std::is_integral<IdT>::value,
+                    T>
+GroupBroadcast(T x, IdT local_id) {
+  using SGIdT = uint32_t;
+  SGIdT sg_local_id = static_cast<SGIdT>(local_id);
+  using OCLT = detail::ConvertToOpenCLType_t<T>;
+  using OCLIdT = detail::ConvertToOpenCLType_t<SGIdT>;
+  OCLT ocl_x = detail::convertDataToType<T, OCLT>(x);
+  OCLIdT ocl_id = detail::convertDataToType<SGIdT, OCLIdT>(sg_local_id);
+  return __spirv_GroupBroadcast(group_scope<Group>::value, ocl_x, ocl_id);
+}
 
 // Broadcast with vector local index
 template <typename Group, typename T, int Dimensions>

sycl/include/CL/sycl/detail/type_traits.hpp

@@ -17,6 +17,10 @@
 
 __SYCL_INLINE_NAMESPACE(cl) {
 namespace sycl {
+template <int Dimensions> class group;
+namespace intel {
+struct sub_group;
+} // namespace intel
 namespace detail {
 namespace half_impl {
 class half;
@@ -302,6 +306,20 @@ template <access::address_space AS, class DataT>
 using const_if_const_AS = DataT;
 #endif
 
+template <typename T> struct is_group : std::false_type {};
+
+template <int Dimensions>
+struct is_group<group<Dimensions>> : std::true_type {};
+
+template <typename T> struct is_sub_group : std::false_type {};
+
+template <> struct is_sub_group<intel::sub_group> : std::true_type {};
+
+template <typename T>
+struct is_generic_group
+    : std::integral_constant<bool,
+                             is_group<T>::value || is_sub_group<T>::value> {};
+
 } // namespace detail
 } // namespace sycl
 } // __SYCL_INLINE_NAMESPACE(cl)

sycl/include/CL/sycl/intel/group_algorithm.hpp

@@ -77,20 +77,6 @@ template <> inline id<3> linear_id_to_id(range<3> r, size_t linear_id) {
   return result;
 }
 
-template <typename T> struct is_group : std::false_type {};
-
-template <int Dimensions>
-struct is_group<group<Dimensions>> : std::true_type {};
-
-template <typename T> struct is_sub_group : std::false_type {};
-
-template <> struct is_sub_group<intel::sub_group> : std::true_type {};
-
-template <typename T>
-struct is_generic_group
-    : std::integral_constant<bool,
-                             is_group<T>::value || is_sub_group<T>::value> {};
-
 template <typename T, class BinaryOperation> struct identity {};
 
 template <typename T, typename V> struct identity<T, intel::plus<V>> {