Re: Creating imaginary inf/nan in GCC

["Kaveh R. Ghazi" <ghazi at caip dot rutgers dot edu>]

From: "Richard Guenther" <richard.guenther@gmail.com>

> > Thanks, I do want to test the middle-end.  However I need to do more than
> > just create the complex expression.  I also have to pass it to a builtin
> > that evaluates using MPC like __builtin_csin().  The fortran frontend
> > evaluates complex transcendentals in fortran/simplify.c, not in the
> > middle-end.  So it wouldn't test what I want AFAICT.  It's not a big 
> > deal,
> > the nan cases are error paths that should *avoid* folding via MPC.
>
> If you go through memory the compiler should promote that to a register
> and constant propagate the result, isn't that enough?

All the previous tests of this nature were in 
gcc.dg/torture/builtin-math-*.c and are done at all opt levels 
including -O0.  I think your suggestion works, but only when optimizing. 
Also, I think it doesn't work with -fdump-tree-original, I'd have to inspect 
a different dump file.  (Any thoughts on which one?)

The obsessive part of my brain wants to keep everything the same as the 
other tests. :-)   But I suppose it would work, I just have to tweek it with 
these things in mind.

       --Kaveh