Compilation of R-cran with GCC CPU march native flag

#Compilation of R-cran with GCC CPU march native flag
wget http://cran.r-project.org/src/base/R-3/R-3.1.2.tar.gz
tar -xzf R-3.1.2.tar.gz
apt-get install -y gcc gfortran g++ libreadline6-dev xserver-xorg-dev libxt-dev libxmu-headers tcl8.6-dev tk8.6-dev
cd  /home/src/R-3.1.2
#Note: Updated the compilation flags for Ofast and mmarc

CFLAGS="-Ofast -march=native  " CXXFLAGS="${CFLAGS}" FCFLAGS="${CFLAGS}"  ./configure --with-cairo --with-x  --with-libpng --with-jpeglib --with-libtiff  --enable-R-shlib --enable-BLAS-shlib --enable-memory-profiling --with-readline --with-tcltk --with-tcl-config=/usr/lib/x86_64-linux-gnu/tcl8.6/tclConfig.sh --with-tk-config=/usr/lib/x86_64-linux-gnu/tk8.6/tkConfig.sh

R is now configured for x86_64-pc-linux-gnu

  Source directory:          .
  Installation directory:    /usr/local

  C compiler:                gcc  -Ofast -march=native  -pipe -mtune=native
  Fortran 77 compiler:       f95  -g -O2

  C++ compiler:              g++  -Ofast -march=native  -pipe -mtune=native
  C++ 11 compiler:           g++  -std=c++11 -Ofast -march=native  -pipe -mtune=native
  Fortran 90/95 compiler:    gfortran -Ofast -march=native  -pipe -mtune=native
  Obj-C compiler:

  Interfaces supported:      X11, tcltk
  External libraries:        readline, zlib, lzma, PCRE, curl
  Additional capabilities:   PNG, JPEG, TIFF, NLS, cairo, ICU
  Options enabled:           shared R library, shared BLAS, R profiling, memory profiling

  Capabilities skipped:
  Options not enabled:

  Recommended packages:      yes

configure: WARNING: you cannot build info or HTML versions of the R manuals
configure: WARNING: you cannot build PDF versions of the R manuals
configure: WARNING: you cannot build PDF versions of vignettes and help pages