Re: a question for the c/c++ front end / standards people.

[Kenneth Zadeck <zadeck at naturalbridge dot com>]

On 11/05/2012 01:08 PM, Ian Lance Taylor wrote:
> On Mon, Nov 5, 2012 at 10:02 AM, Kenneth Zadeck
> <zadeck@naturalbridge.com> wrote:
> > The question is why is having a case label of 256 on a unsigned char switch
> > legal?
> Are you asking why it is valid in the C language?  Or are you asking
> why it is valid in GIMPLE?  I guess the first question is fairly
> obvious so you are asking about GIMPLE.  I don't personally see a
> problem with declaring that it is invalid in GIMPLE, but of course you
> would need to modify the gimplifier and verify_gimple_stmt to reject
> this code.
>
> Ian
i have been around enough to understand that a lot can unravel when you 
pull on a string.

At the top level, i could ask is it a problem if i make this illegal 
gimple? and by problem i mean does this make the front ends reject some 
legal c program?

the problem seems to be mostly that the front ends need to be calling 
force_fit_type_double (or on my branch force_fit_type_wide rather than 
just double_int_to_tree (or wide_int_to_tree).  This would mean that the 
value would go into the gimple code with overflow bit set.

kenny