Refactor rule derivation slightly (#537)

* Avoid extra function call

* Insert more things directly

* Fix bug

* Fix issue

* Revert previous change

* Revert accidental change

* Bump patch version

Author: willtebbutt

Project.toml

@@ -1,7 +1,7 @@
 name = "Mooncake"
 uuid = "da2b9cff-9c12-43a0-ae48-6db2b0edb7d6"
 authors = ["Will Tebbutt, Hong Ge, and contributors"]
-version = "0.4.111"
+version = "0.4.112"
 
 [deps]
 ADTypes = "47edcb42-4c32-4615-8424-f2b9edc5f35b"

src/interpreter/s2s_reverse_mode_ad.jl

@@ -699,9 +699,12 @@ function make_ad_stmts!(stmt::Expr, line::ID, info::ADInfo)
         #
 
         # Make arguments to rrule call. Things which are not already CoDual must be made so.
-        codual_arg_ids = map(_ -> ID(), collect(args))
-        codual_args = map(args, codual_arg_ids) do arg, id
-            return (id, new_inst(inc_or_const_stmt(arg, info)))
+        codual_args = IDInstPair[]
+        codual_arg_ids = map(args) do arg
+            is_active(arg) && return __inc(arg)
+            id = ID()
+            push!(codual_args, (id, new_inst(inc_or_const_stmt(arg, info))))
+            return id
         end
 
         # Make call to rule.