exactness test only for x86_64 machines, closes #3491 (#3523)
exactness test only for x86_64 machines, closes #3491 (#3523)


vlulla/data.table,vlulla/data.table,vlulla/data.table,jangorecki/data.table,Rdatatable/data.table,Rdatatable/data.table,jangorecki/data.table,vlulla/data.table,Rdatatable/data.table,jangorecki/data.table,jangorecki/data.table,Rdatatable/data.table