diff --git a/base/Base.jl b/base/Base.jl
index 0bfd3b6e7d7b7..42a506479326b 100644
--- a/base/Base.jl
+++ b/base/Base.jl
@@ -177,9 +177,6 @@ include("arraymath.jl")
 include("simdloop.jl")
 using .SimdLoop
 
-# functions for AbstractArray with @simd
-include("abstractarraypatch.jl")
-
 # map-reduce operators
 include("reduce.jl")
 
diff --git a/base/abstractarraypatch.jl b/base/abstractarraypatch.jl
deleted file mode 100644
index eee678fccecaf..0000000000000
--- a/base/abstractarraypatch.jl
+++ /dev/null
@@ -1,55 +0,0 @@
-# This file is a part of Julia. License is MIT: https://julialang.org/license
-
-## copy between abstract arrays - generally more efficient
-## since a single index variable can be used.
-## copyto_unaliased! use @simd to speed up, so these definition is seperated from abstractarray.jl
-
-function copyto!(dest::AbstractArray, src::AbstractArray)
-    isempty(src) && return dest
-    src′ = unalias(dest, src)
-    copyto_unaliased!(IndexStyle(dest), dest, IndexStyle(src′), src′)
-end
-
-function copyto!(deststyle::IndexStyle, dest::AbstractArray, srcstyle::IndexStyle, src::AbstractArray)
-    isempty(src) && return dest
-    src′ = unalias(dest, src)
-    copyto_unaliased!(deststyle, dest, srcstyle, src′)
-end
-
-function copyto_unaliased!(deststyle::IndexStyle, dest::AbstractArray, srcstyle::IndexStyle, src::AbstractArray)
-    isempty(src) && return dest
-    length(dest) >= length(src) || throw(BoundsError(dest, LinearIndices(src)))
-    if deststyle isa IndexLinear
-        if srcstyle isa IndexLinear
-            Δi = firstindex(dest) - firstindex(src)
-            for i in eachindex(src)
-                @inbounds dest[i + Δi] = src[i]
-            end
-        else
-            j = firstindex(dest) - 1
-            @inbounds @simd for I in eachindex(src)
-                dest[j+=1] = src[I]
-            end
-        end
-    else
-        if srcstyle isa IndexLinear
-            i = firstindex(src) - 1
-            @inbounds @simd for J in eachindex(dest)
-                dest[J] = src[i+=1]
-            end
-        else
-            iterdest, itersrc = eachindex(dest), eachindex(src)
-            if iterdest == itersrc
-                # Shared-iterator implementation
-                @inbounds @simd for I in itersrc
-                    dest[I] = src[I]
-                end
-            else
-                for (I,J) in zip(itersrc, iterdest)
-                    @inbounds dest[J] = src[I]
-                end
-            end
-        end
-    end
-    return dest
-end