me quadrant. 
Last, (a mod Pi/2_High) &lt;= (a mod Pi/2) &lt;= (a mod Pi/2_Low). With this implementation, the lower and upper bounds are properly set and they are always lower 
(resp. higher) than the value computed by the standard cos functions on 32 
and 64 bits architecture.
This rewritting has been done in assembly language and is quite efficient.
<p>

Keep in mind that values returned by the standard (C-lib or Ocaml) cos(), 
sin() or tan() functions are still 
different on 32 and 64 bits architecture.