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Date: Wed, 20 May 2009 18:15:00 -0000
From: Mark Mitchell <mark@codesourcery.com>
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To: Richard Guenther <rguenther@suse.de>
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Subject: Re: [PATCH][RFC] Adjust the middle-end memory model
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Richard Guenther wrote:

>>   void f(float *f, int *n) {
>>     for (int i = 0; i < *n; ++i) {
>>       f[i] *= 2;
>>     }
>>   }

> The difference is if you want to sink a load from *n beyond the
> store to f[i] - in which case you ask if there is an anti-dependence
> which we cannot exclude in this case (no TBAA is allowed here).

By "not allowed", you don't mean "would be an invalid optimization", but
rather "will no longer be done by GCC", right?

-- 
Mark Mitchell
CodeSourcery
mark@codesourcery.com
(650) 331-3385 x713