On 2019-11-28, at 07:08:16, Peter Relson wrote: > > <snip> > there's a little-known "mini-bar" at the high-end of the 31-bit address > space > </snip> > (I'd be grateful if citations of earlier plies included the Sender and Date so I might consult the entire text. And if the (old-fashioned) ">" quotation indicators appeared.)
> ... > X'7FFFF000' is a value that can be used to initialize a pointer that you > expect not to be used (and if you do use it, it's an error). That value is > better than 0 because (aside from ZAD) the usage of 0 might well "work" > whereas an AMODE 31/64 reference to x'7FFFF000' will not. > I applaud that. I'll even suggest that XLC should make that the value of NULL. Of course: o that would require that casts between (void *) and ([long] int) perform data conversion. o Some type punning would not work. But I believe that could conform to ANSI C specification. -- gil
