[Rd] Notes on building a gcc toolchain for Rtools (but not multilib)

[Avraham Adler]

On Wed, Mar 11, 2015 at 1:40 AM, Hsiu-Khuern Tang <tangoh at gmail.com> wrote:
> On Tue, Mar 10, 2015 at 8:54 PM, Avraham Adler <avraham.adler at gmail.com> wrote:
>>
>> I successfully rebuilt R-devel_2015-03-09 with the most recent version
>> of Rtools tonight, building both ICU_531 and this time libcurl (7.39)
>> as well (and OpenBLAS, of course). The internet bug is still there,
>> but the rest of make-check all passed with flying colors, as did
>> building 'microbenchmark' from source (with all the other needed
>> packages, including Rcpp and Hsiu-Kheurn's change to NM was *not*
>> used).
>> ...
>
> The NM_FILTER change seems to be needed only when compiling C++ code
> with -std=c++11 or -std=gnu++11.
>
> Even though the current CRAN policy doesn't allow the C++11 standard,
> it would still be useful to document this, perhaps in the Writing R
> Extensions manual.
>
> - Hsiu-Khuern

Hello, Hsiu-Khuern.

All the times I have built, I've passed -std-gnu++11. Specifically, I
pass: -march=native -O3 -mfpmath=sse -std=gnu++11 -msse2avx
-mavx256-split-unaligned-load -mavx256-split-unaligned-store
-mvzeroupper --param l1-cache-line-size=64 --param l1-cache-size=64
--param l2-cache-size=256. I live with the repeated warnings that it
isn't needed for gcc, but I know it takes as I see the same string
(gnu++11) passed when I build Rcpp from inside an R session.

Avi