The -march is local, of course. The question is should Rcpp always enforce at least -O2 or the like? From your answer I guess not.
The reason why not to simply have an optimization flag in the local makevars is that, at least in my experience, some code is faster with O2 and some with O3, and by having one in makevars, I am overriding the cases where the package author (who knows better) is passing a different flag. Of course one can just add that flag and install Rcpp by itself. Thanks again, Avi On Tue, Aug 25, 2015 at 5:50 PM, Dirk Eddelbuettel <e...@debian.org> wrote: > > On 25 August 2015 at 17:39, Avraham Adler wrote: > | I've been testing a GCC 4.9.2-based toolchain for Windows for the last > | week or so, and today fell afoul of the error uncovered here > | <https://stat.ethz.ch/pipermail/r-devel/2015-March/070814.html>. I've > | been passing different optimization flags, and Rcpp compiled properly > | under every one EXCEPT when a -march (ivybridge) flag was passed > | without an optimization flag. In that case, I received the > | "collect2.exe: error: ld returned 5 exit status" error as discussed on > | R-devel. Passing a -mtune flag without an -O flag did not cause an > | error. > | > | Downloading the Rcpp source code and manually adding -O2 to Rcpp's > | Makevars.win, re-tar/gzipping it and installing the local version > | allowed Rcpp to compile properly. > | > | I don't know if it is better to tell people to change their local > | Makevars under HOME/.R to pass -O2 or -O3 (that would probably be a > | call by you, Dirk, as you would know best if O3 would help or hinder), > | or if it is better to have Rcpp enforce it, but it should be noted > | somewhere once a 4.9.2-based Windows is eventually released. > > CRAN disallows non-portable flags such as -march. > > So yes, ~/.R/Makevars it is. > > Dirk > > -- > http://dirk.eddelbuettel.com | @eddelbuettel | e...@debian.org _______________________________________________ Rcpp-devel mailing list Rcpp-devel@lists.r-forge.r-project.org https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel
