Re: GCC floating point usage

[Mark Mitchell <mark at codesourcery dot com>]

> OK, that's a good description.  It's clear, easily understood, and has
> a bunch of consequences I bet you haven't thought of yet :-).
Could well be. :-)

> For instance, consider a program that uses setjmp in one file, which
> contains no use of FP but uses routines from another file that call
> longjmp and do use FP.
I've thought of this one, though.

That's considered user error in VxWorks; no different from reading
from uninitialized memory.

> Note that this doesn't apply to "most code"; assuming vxworks defaults
> to -msoft-float, then -mhard-float is only necessary when it's
> actually necessary to use the FPU.
I said "think about" -- not actually pass the switch.  You still have
to think about in your Makefile, and in a mostly-FP task (say, a
signal processing task), you might have almost-all FP code.

> > So, let's first answer the question: would you accept a patch which had
> > the behavior above, assuming it were otherwise OK?
> It's not a black-and-white issue.  A small, simple, obviously correct
> patch that implements the feature would be much more acceptable than a
> large complex buggy patch.
Well, sure -- that was supposed to be the "otherwise OK" bit. :-)

Are you saying that a good patch to implement this feature would be OK,
for appropriate definition of "good"?

If so, then we can go back to the technical discussion about how best
to implement the imaginary flag.

--
Mark Mitchell                mark@codesourcery.com
CodeSourcery, LLC            http://www.codesourcery.com