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Re: [ub] [c++std-ext-14557] Re: Sized integer types and char bits

From: John Regehr <regehr_at_[hidden]>
Date: Thu, 24 Oct 2013 17:01:55 -0600
We hacked Clang to return a random number for any undefined integer
operation. Stuff breaks. Most of SPEC CINT breaks.

There's no way Unisys's compiler implements non-two's-complement if they
run any substantial amount of C/C++ from the wild.


On 10/24/13, 4:40 PM, Richard Smith wrote:
> On Sat, Oct 19, 2013 at 8:51 PM, Jason Merrill <jason_at_[hidden]
> <mailto:jason_at_[hidden]>> wrote:
> On 10/18/2013 11:15 PM, Lawrence Crowl wrote:
> > There were machines being sold in the 90's that were not two's
> complement, but I've lost track
> > since then.
> http://stackoverflow.com/questions/6971886/exotic-architectures-the-standard-committee-cares-about
> The Unisys machine mentioned in the top-rated answer still seems to
> be sold.
> Has anyone ever written a non-twos-complement C++ compiler for this machine?
> Has anyone ever written *any* non-twos-complement C++ implementation?
> And... does anyone intend to write a non-twos-complement *C++17*
> implementation?
> If the answer to these questions is "don't know", how do we find out?
> Strawman suggestion: remove non-twos-complement support from the
> standard and wait to see if anyone complains (with the intent that we
> would restore such support if there are actual complaints, not just
> hypothetical ones). The world would have nearly four years to notice and
> react. Thoughts?
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Received on 2013-10-25 01:02:12