title: Fortran vs C: Mandelbrot benchmark
body: <p>I stumbled across the <a href="https://benchmarksgame-team.pages.debian.net/benchmarksgame/performance/mandelbrot.html" rel="noreferrer">Benchmark Game (code page)</a> and compared Fortran and C. I was very surprised about the difference in the calculation time on the Mandelbrot test (<em>Fortran is 4.3 times slower!</em>) because both languages have very similar feature sets. 
  Moreover, Fortran should be able to optimize more radical (see e.g. <a href="https://stackoverflow.com/questions/146159/is-fortran-easier-to-optimize-than-c-for-heavy-calculations">"Is Fortran easier to optimize than C for heavy calculations?"</a>). </p>
  
  <p>Can one explain which feature is missing in Fortran which would be needed to gain a speed such as in the C example? (It seems that the bit-operations <a href="https://benchmarksgame-team.pages.debian.net/benchmarksgame/program/mandelbrot-gpp-1.html" rel="noreferrer">here</a> are boosting the code.)</p>
  
  <p>EDIT: It is not a question on which programing language is better (there are always many aspects which play a role). It is rather a fundamental question on the difference of optimization in this example.</p>
  
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  <p><strong>Add-on</strong> to the answer by Peter Cordes: There is a paper on <a href="https://hal.inria.fr/hal-01688488/document" rel="noreferrer">Basics of Vectorization for Fortran Applications</a> which also shortly discusses SIMD in Fortran programming. For Intel compilers: <a href="https://software.intel.com/en-us/articles/explicit-vector-programming-in-fortran" rel="noreferrer">Explicit Vector Programming in Fortran</a></p>