Add query function for if we are executing on a GPU

Project.toml

@@ -1,7 +1,7 @@
 name = "KernelAbstractions"
 uuid = "63c18a36-062a-441e-b654-da1e3ab1ce7c"
 authors = ["Valentin Churavy <[email protected]> and contributors"]
-version = "0.9.9"
+version = "0.10.0"
 
 [deps]
 Adapt = "79e6a3ab-5dfb-504d-930d-738a2a938a0e"

src/KernelAbstractions.jl

@@ -372,6 +372,13 @@ macro index(locale, args...)
     Expr(:call, GlobalRef(KernelAbstractions, index_function), esc(:__ctx__), map(esc, args)...)
 end
 
+"""
+    isongpu()
+
+Returns if this kernel is currently executing on a GPU.
+"""
+function isongpu end
+
 ###
 # Internal kernel functions
 ###

src/cpu.jl

@@ -158,6 +158,8 @@ end
     end
 end
 
+isongpu() = false
+
 ###
 # CPU implementation of shared memory
 ###