[cfe-commits] r44058 - in /cfe/trunk: Sema/SemaExpr.cpp test/Sema/floating-point-compare.c

[Neil Booth]

Ted Kremenek wrote:-

> >More generally, should it be suppressed for comparisons against
> >any FP constant that is exact as written?
> >
> >Neil.
> 
> I'm not certain.  Also, I wonder if the following two cases should be  
> treated separately:
> 
>   x == 0.0
> 
> and
> 
>  x == 3.14159  (or any non-zero constant)
> 
> The first case still isn't really kosher either, but suppressing  
> warnings for explicit tests against 0.0 probably will suppress more  
> false positives than the number of false negatives it will cause.

Indeed, and same for 1.0 and -1.0 etc.  All those numbers are exact
as written.

> I think the second case is far more likely to be an error.

3.14159 is not exact as written so would be diagnosed under my
proposal.

Neil.