Re: Reporting bugs: there is nothing to gain in frustrating reporters

[Mattias Karlsson <betasoft at acc dot umu dot se>]

On Sat, 18 Jun 2005, Robert Dewar wrote:

> Mattias Karlsson wrote:
> > On Sat, 18 Jun 2005, Robert Dewar wrote:
> >
> > > Mattias Karlsson wrote:
> > >
> > > > Don't know about you, but I consider any processor that is unable to 
> > > > store a register to memory and then read back the same value to be buggy.
> > >
> > >
> > > THe x86/x87 does not violate this requirement
>
> > In my Obi-Wan-Point-Of-View it does. :-)
>
> Well I think it is inapprorpiate to assign erroneous points of
> view to Obi-Wan :-) Once again, on the x86/x87 the process IS "able
> to store a register to memory and then read back the same value".
> ANy claim to the contrary is ill-informed.
>
> > This entire debate comes from one thing: currently floating point has 
> > always type long double untill stored to memory, regardless of 
> > user-specified type. At -O1 this becomes more or less non-deterministic.
>
> Yes, right, but that is a different issue from being able to store
> a register to memory and then read back the same value.

I confess of being overly generic, and quite fuzzy about my point.


Anyway my point of view is that the solution to anyone needing strict IEEE 
semantics are:
1) Use -float-store
2) Use sse math
3) Learn to live without it.

Since the "gcc-is-buggy" solution of changing x87 rounding modes will:
1) Be a lot of work.
2) Cause a lot of regressions.