[KA] support unified memory API

Author: simeonschaub

src/OpenCLKernels.jl

@@ -17,9 +17,15 @@ export OpenCLBackend
 struct OpenCLBackend <: KA.GPU
 end
 
-KA.allocate(::OpenCLBackend, ::Type{T}, dims::Tuple) where T = CLArray{T}(undef, dims)
-KA.zeros(::OpenCLBackend, ::Type{T}, dims::Tuple) where T = OpenCL.zeros(T, dims)
-KA.ones(::OpenCLBackend, ::Type{T}, dims::Tuple) where T = OpenCL.ones(T, dims)
+function KA.allocate(::OpenCLBackend, ::Type{T}, dims::Tuple; unified::Bool = false) where T
+    if unified
+        return CLArray{T, length(dims), cl.UnifiedSharedMemory}(undef, dims)
+    else
+        return CLArray{T}(undef, dims)
+    end
+end
+
+KA.supports_unified(::OpenCLBackend) = cl.usm_supported(cl.device())
 
 KA.get_backend(::CLArray) = OpenCLBackend()
 # TODO should be non-blocking