You are viewing a plain text version of this content. The canonical link for it is here.

Posted to issues@systemml.apache.org by "Berthold Reinwald (JIRA)" <ji...@apache.org> on 2017/12/21 06:05:03 UTC

[jira] [Updated] (SYSTEMML-1570) Remove fused sel+ operator

     [ https://issues.apache.org/jira/browse/SYSTEMML-1570?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Berthold Reinwald updated SYSTEMML-1570:
----------------------------------------
    Fix Version/s:     (was: SystemML 1.0)
                   SystemML 1.1

> Remove fused sel+ operator
> --------------------------
>
>                 Key: SYSTEMML-1570
>                 URL: https://issues.apache.org/jira/browse/SYSTEMML-1570
>             Project: SystemML
>          Issue Type: Task
>            Reporter: Matthias Boehm
>             Fix For: SystemML 1.1
>
>
> The fused operator sel+ (select positive values) is applied for patterns like (X>0)*X and max(X,0) in order to eliminate unnecessary intermediates. It stems from a time when max was sparse-unsafe and hence inefficient over sparse data. However, meanwhile we mark scalar operators as conditionally sparse-safe depending on the given scalar constant c, which applies for max if c<=0. Hence, this sel+ operator is meanwhile completely useless and should be removed.
> Furthermore, we should also generalize the rewrites to rewrite the selection of negative values (X<0)*X to min(X,0)



--
This message was sent by Atlassian JIRA
(v6.4.14#64029)