[Bug tree-optimization/18792] ICE with -O1 -ftree-loop-linear on small test case

["rakdver at atrey dot karlin dot mff dot cuni dot cz" <gcc-bugzilla at gcc dot gnu dot org>]

------- Additional Comments From rakdver at atrey dot karlin dot mff dot cuni dot cz  2004-12-07 23:13 -------
Subject: Re:  ICE with -O1 -ftree-loop-linear on small test case

> ------- Additional Comments From dberlin at dberlin dot org  2004-12-07 23:09 -------
> Subject: Re:  ICE with -O1 -ftree-loop-linear
>  on small test case
> 
> It's actually a bug in compute_data_dependence then, not linear xforms.
> 
> the dist and dir vector computation functions need to map between the 
> loops we've asked for, and indexes in their array, in a different way.
> 
> Currently this is done by assuming that the indexes are sequential, and 
> we just subtract the index of the top of the nest, and use that as the 
> index into the array.
> If the loop indexes aren't sequential in a nest, this won't work.
> We'll have to use a mapping array or something.

You may use the loop->depth field for indexing the array instead.  It is always
updated, and of course increases sequentially within the loop nest.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18792