Enzyme >= 0.12 compatibility

Project.toml

@@ -24,7 +24,7 @@ ParallelStencil_EnzymeExt = "Enzyme"
 AMDGPU = "0.6, 0.7, 0.8, 0.9, 1"
 CUDA = "3.12, 4, 5"
 CellArrays = "0.2.1"
-Enzyme = "0.11"
+Enzyme = "0.11, 0.12, 0.13"
 MacroTools = "0.5"
 Polyester = "0.7"
 StaticArrays = "1"

src/ParallelKernel/EnzymeExt/autodiff_gpu.jl

@@ -2,18 +2,36 @@ import ParallelStencil
 import ParallelStencil: PKG_THREADS, PKG_POLYESTER
 import Enzyme
 
-function ParallelStencil.ParallelKernel.AD.init_AD(package::Symbol)
-    if iscpu(package)
-        Enzyme.API.runtimeActivity!(true) # NOTE: this is currently required for Enzyme to work correctly with threads
+# function ParallelStencil.ParallelKernel.AD.init_AD(package::Symbol)
+#     if iscpu(package)
+#         Enzyme.API.runtimeActivity!(true) # NOTE: this is currently required for Enzyme to work correctly with threads
+#     end
+# end
+
+# ParallelStencil injects a configuration parameter at the end, for Enzyme we need to wrap that parameter as a Annotation
+# for all purposes this ought to be Const. This is not ideal since we might accidentially wrap other parameters the user
+# provided as well. This is needed to support @parallel autodiff_deferred(...)
+ function promote_to_const(args...)
+    ntuple(length(args)) do i
+        @inline
+        if !(args[i] isa Enzyme.Annotation ||
+            (args[i] isa UnionAll && args[i] <: Enzyme.Annotation) || # Const
+            (args[i] isa DataType && args[i] <: Enzyme.Annotation)) # Const{Nothing}
+            return Enzyme.Const(args[i])
+        else
+            return args[i]
+        end
     end
 end
 
 function ParallelStencil.ParallelKernel.AD.autodiff_deferred!(arg, args...) # NOTE: minimal specialization is used to avoid overwriting the default method
+    args = promote_to_const(args...)
     Enzyme.autodiff_deferred(arg, args...)
     return
 end
 
 function ParallelStencil.ParallelKernel.AD.autodiff_deferred_thunk!(arg, args...) # NOTE: minimal specialization is used to avoid overwriting the default method
+    args = promote_to_const(args...)
     Enzyme.autodiff_deferred_thunk(arg, args...)
     return
 end

test/ParallelKernel/test_parallel.jl

@@ -113,8 +113,8 @@ import Enzyme
                         end
                         return
                     end
-                    @parallel configcall=f!(A, B, a) AD.autodiff_deferred!(Enzyme.Reverse, f!, DuplicatedNoNeed(A, Ā), DuplicatedNoNeed(B, B̄), Const(a))
-                    Enzyme.autodiff_deferred(Enzyme.Reverse, g!, DuplicatedNoNeed(A_ref, Ā_ref), DuplicatedNoNeed(B_ref, B̄_ref), Const(a))
+                    @parallel configcall=f!(A, B, a) AD.autodiff_deferred!(Enzyme.Reverse, Const(f!), Const, DuplicatedNoNeed(A, Ā), DuplicatedNoNeed(B, B̄), Const(a))
+                    Enzyme.autodiff_deferred(Enzyme.Reverse, Const(g!),Const, DuplicatedNoNeed(A_ref, Ā_ref), DuplicatedNoNeed(B_ref, B̄_ref), Const(a))
                     @test Array(Ā) ≈ Ā_ref
                     @test Array(B̄) ≈ B̄_ref
                 end