Re: [PING][PATCH][REVISED] Fix PR middle-end/PR28690, modify swap_commutative_operands_p

[Michael Matz <matz at suse dot de>]

Hi,

On Thu, 21 Jun 2007, H. J. Lu wrote:

> > Note that trunk miscomples dealII anyway, see PR32303 (an instance of 
> > PR30252), which is fixed (or worked around depending on whom you ask) 
> > in 4.2 but not on trunk.  The nature of the bug makes it possible that 
> > it's randomly exposed or hidden by unrelated changes.
> 
> -O2 has been OK on dealII.

I know, but just changing the number of vops until grouping (which -O3 
happens to do) exposes the bug already, so any other changes which might 
lead to different grouping might expose it too.  I'm not saying that there 
can't be some other error additionally, just that we know of at least one 
miscompilation of dealII, which might or might not result also in this 
error.  Perhaps you can check by applying the patch for 4.2 to trunk and 
see if the error persists, then we would know for sure.


Ciao,
Michael.