R help - Aug 2014 - Old g++ in Rtools

I recently downloaded Rtools. I see the g++ version is
gcc version 4.6.3 20111208 (prerelease) (GCC)

I also recently downloaded MinGW. Its version of g++ is
gcc version 4.8.1 (GCC)

I believe that later versions of g++ provide better support for C++11.
Why does Rtools provide a version considerably older than the latest?
Any plans to update the version?
Is it bad practice to compile with a later version when interfacing with R?

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I’m working on a Mac so ymmv, but I’ve been running benchmarks of vanilla R from
cran vs. recompiles with different versions of gcc and R, and I see a speedup of
20-30% vs the cran binary after recompiling with gnu 4.9.  Its quite distinct.  

Each jump in gcc revision (4.7-4.8, 4.8-4.9) seems to improve benchmark
performance by around 10% over the previous generation.  

So there may be advantages to recompiling yourself.

On the other hand, there may be potential issues compiling some packages.  Some
of the benchmarking I’ve been doing is 3.1.1 vs. pqR (distinctly faster than
3.1.1, even without “helper threads”), which is based on R 2.15.0, which in turn
forces you to use older versions of some packages, some of which have
language-compatibility issues with recent compilers.  The version of Rcpp that
accepts R 2.15.0, for example, won’t compile against gcc 4.9.  You may find that
the current versions of other packages have similar issues with recent gnu
compilers, I can’t say.  

I’m surprised, frankly, that there isn’t more discussion of this, considering
the size of the data and complexity of the problems people are feeding into R,
and the possibility of essentially “free” performance boosts.

-- 
Amos Elberg
Sent with Airmail

From: Rguy <rguy@123mail.org>
Reply: Rguy <rguy@123mail.org>>
Date: August 6, 2014 at 2:47:47 AM
To: r-help@r-project.org <r-help@r-project.org>>
Subject:  [R] Old g++ in Rtools  

I recently downloaded Rtools. I see the g++ version is  
gcc version 4.6.3 20111208 (prerelease) (GCC)  

I also recently downloaded MinGW. Its version of g++ is  
gcc version 4.8.1 (GCC)  

I believe that later versions of g++ provide better support for C++11.  
Why does Rtools provide a version considerably older than the latest?  
Any plans to update the version?  
Is it bad practice to compile with a later version when interfacing with R?  

[[alternative HTML version deleted]]  

______________________________________________  
R-help@r-project.org mailing list  
https://stat.ethz.ch/mailman/listinfo/r-help  
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html  
and provide commented, minimal, self-contained, reproducible code.  

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On Wed, Aug 6, 2014 at 2:46 AM, Rguy <rguy at 123mail.org>
wrote:
> I recently downloaded Rtools. I see the g++ version is
> gcc version 4.6.3 20111208 (prerelease) (GCC)
>
> I also recently downloaded MinGW. Its version of g++ is
> gcc version 4.8.1 (GCC)
>
> I believe that later versions of g++ provide better support for C++11.
> Why does Rtools provide a version considerably older than the latest?
> Any plans to update the version?
> Is it bad practice to compile with a later version when interfacing with R?
Later versions of gcc/g++ also support openmp which 4.6.3 does not.

There may be other C/C++ packages too that can't be used until with
Rtools until it is upgraded to a more recent version.

By the way, there is a MinGW 4.8.2 distribution (slightly more recent
than the one you downloaded) here:
http://nuwen.net/mingw.html


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