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Re: [patch] Fix PR tree-optimization/46213

Hi,

On Thu, 4 Nov 2010, Richard Guenther wrote:

> On Thu, Nov 4, 2010 at 12:51 PM, Ira Rosen <IRAR@il.ibm.com> wrote:
> >
> > Hi,
> >
> > MINUS_EXPR in reduction is supposed to be supported for computations of the
> > form: res = res - a[i], and not for res = a[i] - res, but this is not
> > checked. The attached patch adds such check.
> 
> We can simply support this by treating is as
> 
>   tmp = -a[i];
>   res = res + tmp;

That would be res = res - a[i], which we _do_ support :)  res = X - res is 
an alternating progression, not so easily supported.


Ciao,
Michael.
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