[Bug tree-optimization/48052] loop not vectorized if index is "unsigned int"

["vincenzo.innocente at cern dot ch" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48052

--- Comment #4 from vincenzo Innocente <vincenzo.innocente at cern dot ch> 2011-03-10 10:54:07 UTC ---
  Thanks for the fast reation.
I would like to point out that, at least on x86_64, the only one that does not
work is
"unsigned int"
"unsigned long long (aka size_t)" seems to work (see 3,4 and 5th loop in my
example)

vincenzo


On 10 Mar, 2011, at 11:23 AM, paolo.carlini at oracle dot com wrote:

> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48052
> 
> --- Comment #3 from Paolo Carlini <paolo.carlini at oracle dot com> 2011-03-10 10:22:48 UTC ---
> Thanks for the analysis. I knew about the difference between signed and
> unsigned, makes sense. Not knowing in detail the internals of the optimization
> the puzzling bit is that types wider than unsigned int already work fine. The
> problem seems fixable, somehow ;)
> 
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--
Il est bon de suivre sa pente, pourvu que ce soit en montant. 
A.G.
http://www.flickr.com/photos/vin60/1320965757/