hvncat: Added inbounds annotations that improve performance

base/abstractarray.jl

@@ -2410,7 +2410,7 @@ function hvncat_fill!(A::Array, row_first::Bool, xs::Tuple)
         nrc = nr * nc
         na = prod(size(A)[3:end])
         k = 1
-        for d ∈ 1:na
+        @inbounds for d ∈ 1:na
             dd = nrc * (d - 1)
             for i ∈ 1:nr
                 Ai = dd + i
@@ -2422,7 +2422,7 @@ function hvncat_fill!(A::Array, row_first::Bool, xs::Tuple)
             end
         end
     else
-        for k ∈ eachindex(xs)
+        @inbounds for k ∈ eachindex(xs)
             A[k] = xs[k]
         end
     end
@@ -2609,28 +2609,36 @@ function _typed_hvncat_shape(::Type{T}, shape::NTuple{N, Tuple}, row_first, as::
     return A
 end
 
-function hvncat_fill!(A::AbstractArray{T, N}, scratch1::Vector{Int}, scratch2::Vector{Int}, d1::Int, d2::Int, as::Tuple{Vararg}) where {T, N}
+function hvncat_fill!(A::AbstractArray{T, N}, scratch1::Vector{Int}, scratch2::Vector{Int},
+                              d1::Int, d2::Int, as::Tuple) where {T, N}
+    N > 1 || throw(ArgumentError("dimensions of the destination array must be at least 2"))
+    length(scratch1) == length(scratch2) == N ||
+        throw(ArgumentError("scratch vectors must have as many elements as the destination array has dimensions"))
+    0 < d1 < 3 &&
+    0 < d2 < 3 &&
+    d1 != d2 ||
+        throw(ArgumentError("d1 and d2 must be either 1 or 2, exclusive."))
     outdims = size(A)
     offsets = scratch1
     inneroffsets = scratch2
     for a ∈ as
         if isa(a, AbstractArray)
             for ai ∈ a
-                Ai = hvncat_calcindex(offsets, inneroffsets, outdims, N)
+                @inbounds Ai = hvncat_calcindex(offsets, inneroffsets, outdims, N)
                 A[Ai] = ai
 
-                for j ∈ 1:N
+                @inbounds for j ∈ 1:N
                     inneroffsets[j] += 1
                     inneroffsets[j] < cat_size(a, j) && break
                     inneroffsets[j] = 0
                 end
             end
         else
-            Ai = hvncat_calcindex(offsets, inneroffsets, outdims, N)
+            @inbounds Ai = hvncat_calcindex(offsets, inneroffsets, outdims, N)
             A[Ai] = a
         end
 
-        for j ∈ (d1, d2, 3:N...)
+        @inbounds for j ∈ (d1, d2, 3:N...)
             offsets[j] += cat_size(a, j)
             offsets[j] < outdims[j] && break
             offsets[j] = 0