hvncat: Added inbounds annotations that improve performance (#41200)

* Added judicious inbounds/inline decorations

* add inline to other one

* bump

* grammar

Co-authored-by: Jeff Bezanson <jeff.bezanson@gmail.com>

* Remove `@inline`

* bump CI

* bump CI 2

* Merge fix

* Ensure `hvncat_fill!` can't execute when N < 2

* Bounds check in three-arg `hvncat_fill!`

* Narrow inbounds

* Moved bounds check up

---------

Co-authored-by: Jeff Bezanson <jeff.bezanson@gmail.com>

Author: BioTurboNick

base/abstractarray.jl

@@ -2404,26 +2404,30 @@ function _typed_hvncat(::Type{T}, dims::NTuple{N, Int}, row_first::Bool, xs::Num
 end
 
 function hvncat_fill!(A::Array, row_first::Bool, xs::Tuple)
+    nr, nc = size(A, 1), size(A, 2)
+    na = prod(size(A)[3:end])
+    len = length(xs)
+    nrc = nr * nc
+    if nrc * na != len
+        throw(ArgumentError("argument count $(len) does not match specified shape $(size(A))"))
+    end
     # putting these in separate functions leads to unnecessary allocations
     if row_first
-        nr, nc = size(A, 1), size(A, 2)
-        nrc = nr * nc
-        na = prod(size(A)[3:end])
         k = 1
         for d ∈ 1:na
             dd = nrc * (d - 1)
             for i ∈ 1:nr
                 Ai = dd + i
                 for j ∈ 1:nc
-                    A[Ai] = xs[k]
+                    @inbounds A[Ai] = xs[k]
                     k += 1
                     Ai += nr
                 end
             end
         end
     else
         for k ∈ eachindex(xs)
-            A[k] = xs[k]
+            @inbounds A[k] = xs[k]
         end
     end
 end
@@ -2609,28 +2613,36 @@ 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