[cfe-dev] [analyzer] What is RangeSet::Negate idea

[Artem Dergachev via cfe-dev]

Yup, and Negate() flips this sequence of segments around zero, i.e. 
[/a/, /b]/ U [/c/, /d/] => [-/d/, -/c/] U [-/b/, -/a/]. In other words, 
if R is the range for $x, then R.Negate() is the range for -x.

Negate() also handles MIN differently because -MIN is unrepresentable 
for most integer types.

On 4/6/20 6:22 PM, Denis Petrov via cfe-dev wrote:
>
> Hi, community.
>
>
> Who can explain the main idea of *RangeSet::Negate*? And how does 
> *RangeSet*​work?
>
>
> As I understand *RangeSet* may hold several constraint ranges 
> /(e.g. [MIN,10] U [20,30] U [40,MAX])/ or may be empty /(no 
> constraints, in other words, holds everything [MIN, MAX])/,
>
> when MIN and MAX are kinda *numeric**_limits<*/type //which 
> corresponds to particular SymExpr​/*>::min/max()*.
>
> Am I correct? If I am not, please explain.
>
>
> P.S. fixed wrong subject format.
>
>
> ------------------------------------------------------------------------
> *Denys Petrov*
> Senior С++ Developer | Kharkiv, Ukraine
>
>
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