def memcpy_region(typingctx, dst, dst_offset, src, src_offset, nbytes, align):
    '''Copy nbytes from *(src + src_offset) to *(dst + dst_offset)'''
    def codegen(context, builder, signature, args):
        [dst_val, dst_offset_val, src_val, src_offset_val, nbytes_val,
         align_val] = args
        src_ptr = builder.gep(src_val, [src_offset_val])
        dst_ptr = builder.gep(dst_val, [dst_offset_val])
        cgutils.raw_memcpy(builder, dst_ptr, src_ptr, nbytes_val, align_val)
        return context.get_dummy_value()

    sig = types.void(types.voidptr, types.intp, types.voidptr, types.intp,
                     types.intp, types.intp)
    return sig, codegen
Copy nbytes from *(src + src_offset) to *(dst + dst_offset)
numba/core/unsafe/bytes.py