how to force all double precision in 64-bit (and not any 80-bit registers)
<p>I am trying to get a numerical package to give the same results on two different platforms (linux and macos) in order to rule out bugs/hardware problems.  I suspect the current source of differences is different 64-bit vs. 80-bit double precision arithmetic.  I know there are compiler options for gcc to control this but I thought there was also a function call to set this, as well as something that can be done on the command line or shell environment.</p>

<p>Any ideas?</p>
