[llvm-dev] RFC: Killing undef and spreading poison

[Bruce Hoult via llvm-dev]

On Tue, Oct 18, 2016 at 3:06 PM, Nuno Lopes via llvm-dev <
llvm-dev at lists.llvm.org> wrote:

> Hi,
>
> Over the past few years we've been trying to kill poison somehow. There
> have
> been a few proposals, but they've all failed to pass the bar and/or to
> gather significant support (my own proposals included).
>

Ok, freeze() produces a fixed but undefined value, so that xor'ing the same
frozen value produces 0, ANDing a frozen value with 1 produces known zero
bits everywhere except the LSB, which is undefined.

Does every instance of freeze() produce a *different* fixed but undefined
value? i.e. the value produced by freeze() is labelled with a sequence
number or something like that?
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20161018/1edfcb0e/attachment.html>