title: How can I compile *without* various instruction sets enabled?
body: <p>I am attempting to recompile some software with various instruction sets, specifically, <code>SSE</code>, <code>SSE2</code>, <code>SSE3</code>, <code>SSSE3</code>, <code>SSE4.1</code>, <code>SSE4.2</code>, and <code>AVX</code>, and I would like to see how the code performs <em>without</em> these instruction sets to make sure I am getting the full effect of them.</p>
  
  <p>For example, I want to compile it with just <code>-O2</code> with a <code>gnu</code> compiler and see how it performs when restricting it to <em>only</em> <code>SSE</code>, to see which flags it is invoking by default. I also have an <code>intel</code> compiler that I am working with and I would like to isolate what each flag (or combination of flags) is doing to my code, so how can I specify <em>exactly</em> which flags are being invoked?</p>
  
  <p>If it matters, I am working with <code>C</code>, <code>C++</code>, and <code>Fortran</code> on <code>Linux</code>.</p>