Intel Compiler on Linux

• Make sure you have access to root. (eg: sudo su root, passwd)
  
• Make sure you have your build environment set up. eg:
  
  

  sudo apt-get install gcc
  sudo apt-get install build-essential
  sudo apt-get install g++
  sudo apt-get install rpm
  

• ICC requires older standard C libraries, libstdc++5, so you can get them for Ubuntu from:
  Package: libstdc++5. You just need to download the i386 package. (eg from the Australian mirror, by using wget [url]), and then install it, eg: "sudo dpkg -i libstdc++5_3.3.6-18_i386.deb".
  If you don't do this you may get the following error messages:
  
  

  Missing critical pre-requisite
  -- missing system commands
  
  The following required for installation commands are missing:
  libstdc++.so.5 ( library)
  

• Download ICC
  
• Unzip (tar -xvf filename)
  
• ./install.sh
  
• Choose to install for all (1)
  
• Read "welcome" message follow instructions for licence, etc.
  
• Activate your software (1) and provide the serial number that came in your email. You should see "Activation Completed Successfully"
  
• Install the software (requires 3.35 gigs). You should see a message "Checking the prerequisites. It can take several minutes. Please wait…".
  
• You might see:
  
  

  Missing optional pre-requisite
  -- No compatible Java* Runtime Environment (JRE) found
  -- operating system type is not supported.
  -- system glibc or kernel version not supported or not detectable
  -- binutils version not supported or not detectable
  

  The JRE you need for the visual debugger, otherwise you can safely continue.
  
• The installer then asks which components to install, eg "Intel(R) C++ Compiler Professional Edition for Linux*", just press "1. Install" to continue. It should state "component installed successfully."
  
• Setup the paths, you can use the iccvars.sh in /opt/intel/Compiler/11.1/073/bin to setup everything for you. (eg: source /opt/intel/Compiler/11.1/073/bin/iccvars.sh ia32). You may wish to put it into your .bashrc file.
  
• That's it! Type "icc" to invoke for C files or "icpc" for C++ files. For standard makefiles use "make CXX=icpc"
  

On a 1GHz VIA Esther processor, GCC 4.4.1, with -O2 -march=c3-2:

real 0m16.855s
user 0m16.849s
sys 0m0.004s

And, with ICC 11.1, with -O2:

real 0m11.369s
user 0m11.361s
sys 0m0.008s

An instant 45% speedup! Unfortunately not all code makes such a big change, some other compute-intensive code I tested only got a 4% speedup. In any case I'd say its worth it!