switch to using Fields as temporaries

src/DataLayouts/DataLayouts.jl

@@ -15,7 +15,7 @@ indexes the underlying array as `[i,j,k,f,v,h]`
 module DataLayouts
 
 import Base: Base, @propagate_inbounds
-import StaticArrays: SOneTo, MArray
+import StaticArrays: SOneTo, MArray, SArray
 import ClimaComms
 
 import ..enable_threading, ..slab, ..slab_args, ..column, ..column_args, ..level
@@ -626,6 +626,16 @@ function IJF{S, Nij}(array::AbstractArray{T, 3}) where {S, Nij, T}
  IJF{S, Nij, typeof(array)}(array)
 end
 
+function IJF{S, Nij}(::Type{MArray}, ::Type{T}) where {S, Nij, T}
+ Nf = typesize(T, S)
+ array = MArray{Tuple{Nij, Nij, Nf}, T, 3, Nij * Nij * Nf}(undef)
+ IJF{S, Nij}(array)
+end
+function SArray(ijf::IJF{S, Nij, <:MArray}) where {S, Nij}
+ IJF{S, Nij}(SArray(parent(ijf)))
+end
+
+
 function replace_basetype(data::IJF{S, Nij}, ::Type{T}) where {S, Nij, T}
  array = parent(data)
  S′ = replace_basetype(eltype(array), T, S)
@@ -670,6 +680,9 @@ end
  data::IJF{S, Nij},
  i::Integer,
  j::Integer,
+ k = nothing,
+ v = nothing,
+ h = nothing,
 ) where {S, Nij}
  @boundscheck (1 <= i <= Nij && 1 <= j <= Nij) ||
  throw(BoundsError(data, (i, j)))
@@ -749,6 +762,14 @@ function IF{S, Ni}(array::AbstractArray{T, 2}) where {S, Ni, T}
  check_basetype(T, S)
  IF{S, Ni, typeof(array)}(array)
 end
+function IF{S, Ni}(::Type{MArray}, ::Type{T}) where {S, Ni, T}
+ Nf = typesize(T, S)
+ array = MArray{Tuple{Ni, Nf}, T, 2, Ni * Nf}(undef)
+ IF{S, Ni}(array)
+end
+function SArray(data::IF{S, Ni, <:MArray}) where {S, Ni}
+ IF{S, Ni}(SArray(parent(data)))
+end
 
 function replace_basetype(data::IF{S, Ni}, ::Type{T}) where {S, Ni, T}
  array = parent(data)
@@ -786,7 +807,14 @@ end
  IF{SS, Ni}(dataview)
 end
 
-@inline function Base.getindex(data::IF{S, Ni}, i::Integer) where {S, Ni}
+@inline function Base.getindex(
+ data::IF{S, Ni},
+ i::Integer,
+ j = nothing,
+ k = nothing,
+ v = nothing,
+ h = nothing,
+) where {S, Ni}
  @boundscheck (1 <= i <= Ni) || throw(BoundsError(data, (i,)))
  @inbounds get_struct(parent(data), S, Val(2), CartesianIndex(i, 1))
 end