[fortran,patch] Support for IEEE underflow control on x86/x86_64

[Uros Bizjak]

On Thu, Jul 3, 2014 at 11:42 AM, FX <fxcoudert@gmail.com> wrote:
>> (I don't think -O0 is needed, but have to check with a testsuite run.)
>
> On x86_64-apple-darwin, -O0 or -O1 are needed: at -O2 my “use_real” call is optimized out anyway, and the division simplified at compile time.

You can mark variables with:

  real, volatile :: x
  double precision, volatile :: y

and you don't even need the call to use_real anymore.

I have tested on alpha that this approach works for all optimization levels.

Uros.