Re: Lists and aliasing (Re: Freeze on 27 February)

[Vladimir 'φ-coder/phcoder' Serbinenko]

On 22.02.2012 19:41, Lennart Sorensen wrote:
> On Wed, Feb 22, 2012 at 01:28:06PM -0500, Lennart Sorensen wrote:
> > Oh the feature for doing multiple #pragma statements throughout the code
> > is new in gcc 4.6.  It can't be done in earlier versions.  In older
> > versions whatever you say last applies to the whole file.
> >
> > Perhaps a slightly ugly solution could solve it by having a #if that
> > checks that gcc is 4.6 or higher around the #pragma that reenables
> > the warning.
> >
> > ie:
> >
> > #if __GNUC__>  4 || (__GNUC__ == 4&&  __GNUC_MINOR__>= 6)
> > #pragma GCC diagnostic error "-Wunsafe-loop-optimizations"
> > #endif
> >
> > At least this way you get to have the warning for most of the code on
> > newer gcc versions, but don't break older gcc versions that are still
> > in common use.
> Well it compiles when I do that at least with gcc 4.4, although obviously
> it does mean -Wunsafe-loop-optimizations is disabled entirely for those
> 4 files rather than just for the one function that causes a problem.
Alternative is to add a condition which will ensure the loop termination 
but don't interfere with it other wise by using the fact that min 
(UINT_MAX, r)=r if r is unsigned int.


--
Regards
Vladimir 'φ-coder/phcoder' Serbinenko

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