Make recursive_add/accumulate more recursive

Author: danielwe

src/compiler.jl

@@ -6562,7 +6562,13 @@ end
         Base.@_inline_meta
         prev = getfield(x, i)
         next = getfield(y, i)
-        recursive_add(prev, next, f, forcelhs)
+        ST = Core.Typeof(prev)
+        if !mutable_register(ST)
+            recursive_add(prev, next, f, forcelhs)
+        elseif !(ST <: Integer)
+            recursive_accumulate(prev, next, f)
+            prev
+        end
     end)
 end
 
@@ -6591,18 +6597,19 @@ end
 
 # Recursively In-place accumulate(aka +=). E.g. generalization of x .+= f(y)
 @inline function recursive_accumulate(x::Array{T}, y::Array{T}, f::F=identity) where {T, F}
-    if !mutable_register(T)
-        for I in eachindex(x)
-            prev = x[I]
+    for I in eachindex(x, y)
+        if !mutable_register(T)
             @inbounds x[I] = recursive_add(x[I], (@inbounds y[I]), f, mutable_register)
+        elseif !(T <: Integer)
+            recursive_accumulate((@inbounds x[I]), (@inbounds y[I]), f)
         end
     end
 end
 
 
 # Recursively In-place accumulate(aka +=). E.g. generalization of x .+= f(y)
 @inline function recursive_accumulate(x::Core.Box, y::Core.Box, f::F=identity) where {F}
-    recursive_accumulate(x.contents, y.contents, seen, f)
+    recursive_accumulate(x.contents, y.contents, f)
 end
 
 @inline function recursive_accumulate(x::T, y::T, f::F=identity) where {T, F}
@@ -6613,12 +6620,14 @@ end
     for i in 1:nf
         if isdefined(x, i)
             xi = getfield(x, i)
+            yi = getfield(y, i)
             ST = Core.Typeof(xi)
             if !mutable_register(ST)
                 @assert ismutable(x)
-                yi = getfield(y, i)
                 nexti = recursive_add(xi, yi, f, mutable_register)
                 setfield!(x, i, nexti)
+            elseif !(ST <: Integer)
+                recursive_accumulate(xi, yi, f)
             end
         end
     end