only define constructors once

Author: vchuravy

src/macros.jl

@@ -38,14 +38,16 @@ function __kernel(expr)
 
     # create constructor functions
     constructors = quote
-        $name(dev::$Device) = $name(dev, $DynamicSize(), $DynamicSize())
-        $name(dev::$Device, size) = $name(dev, $StaticSize(size), $DynamicSize())
-        $name(dev::$Device, size, range) = $name(dev, $StaticSize(size), $StaticSize(range))
-        function $name(::Device, ::S, ::NDRange) where {Device<:$CPU, S<:$_Size, NDRange<:$_Size}
-            return $Kernel{Device, S, NDRange, typeof($cpu_name)}($cpu_name)
-        end
-        function $name(::Device, ::S, ::NDRange) where {Device<:$GPU, S<:$_Size, NDRange<:$_Size}
-            return $Kernel{Device, S, NDRange, typeof($gpu_name)}($gpu_name)
+        if !@isdefined($name)
+            $name(dev::$Device) = $name(dev, $DynamicSize(), $DynamicSize())
+            $name(dev::$Device, size) = $name(dev, $StaticSize(size), $DynamicSize())
+            $name(dev::$Device, size, range) = $name(dev, $StaticSize(size), $StaticSize(range))
+            function $name(::Device, ::S, ::NDRange) where {Device<:$CPU, S<:$_Size, NDRange<:$_Size}
+                return $Kernel{Device, S, NDRange, typeof($cpu_name)}($cpu_name)
+            end
+            function $name(::Device, ::S, ::NDRange) where {Device<:$GPU, S<:$_Size, NDRange<:$_Size}
+                return $Kernel{Device, S, NDRange, typeof($gpu_name)}($gpu_name)
+            end
         end
     end
 

test/unroll.jl

@@ -7,9 +7,17 @@ using KernelAbstractions.Extras
   end
 end
 
+@kernel function kernel_unroll!(a, ::Val{N}) where N
+  @unroll for i in 1:N
+    @inbounds a[i] = i
+  end
+end
+
 let
   a = zeros(5)
   kernel! = kernel_unroll!(CPU(), 1, 1)
   event = kernel!(a)
   wait(event)
+  event = kernel!(a, Val(5))
+  wait(event)
 end