[R-sig-hpc] Intel Phi Coprocessor? -> i5/i7 instruction set in R binary?

[Rodney Sparapani]

On 06/10/2013 01:53 PM, ivo welch wrote:
> thx again, simon.  by stock R, I mean the compiled binaries in
> http://cran.r-project.org/bin/linux/  .  dirk e compiled it as
>
>
> /etc/R/Makeconf:# configure  '--prefix=/usr' '--with-cairo'
> '--with-jpeglib' '--with-readline' '--with-tcltk'
> '--with-system-bzlib' '--with-system-pcre' '--with-system-zlib'
> '--mandir=/usr/share/man' '--infodir=/usr/share/info'
> '--datadir=/usr/share/R/share' '--includedir=/usr/share/R/include'
> '--with-blas' '--with-lapack' '--enable-R-profiling'
> '--enable-R-shlib' '--enable-memory-profiling'
> '--without-recommended-packages' '--build' 'x86_64-linux-gnu'
> 'build_alias=x86_64-linux-gnu' 'R_PRINTCMD=/usr/bin/lpr'
> 'R_PAPERSIZE=letter' 'R_BROWSER=xdg-open' 'LIBnn=lib' 'CC=gcc
> -std=gnu99' 'CFLAGS=-O2 -pipe -g' 'LDFLAGS=' 'CPPFLAGS='
> 'F77=gfortran' 'FFLAGS=-O2 -pipe -g' 'CXX=g++' 'CXXFLAGS=-O2 -pipe -g'
> 'FC=gfortran' 'FCFLAGS=-O2 -pipe -g'
> /etc/R/Makeconf:CC = gcc -std=gnu99

Dirk helpfully told me that the switch to compile for your
particular processor (and it's SIMD dialect) is -march=native,
i.e. "-g -O2 -march=native".  For my testing (with my examples) on
AMD64 with Linux this produces about a 2X speedup with interpreted R.
But, if you go beyond that to hand coding your functions with C/C++ via
Rcpp, RcppEigen, etc. the speedups can be dramatic:
35-70X speedup from R code is routine in my experience.

Rodney