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Re: GCC missed optimization?
- From: "Richard Guenther" <richard dot guenther at gmail dot com>
- To: "Devang Patel" <devang dot patel at gmail dot com>
- Cc: "Dorit Nuzman" <DORIT at il dot ibm dot com>, fxcoudert at gmail dot com, "GCC Mailing List" <gcc at gcc dot gnu dot org>
- Date: Tue, 1 Aug 2006 10:48:22 +0200
- Subject: Re: GCC missed optimization?
- References: <44CE43FF.email@example.com>
On 7/31/06, Devang Patel <firstname.lastname@example.org> wrote:
>>I think this patch by Zdenek - vectorizing function calls - is related:
>> (would need to be extended to cover this case).
Yes, extending Zdenek's patch to recognize built-in is a good idea.
However, in case of compiler inserted built-in (e.g. this case) it is
a good idea to delay inserting built-in function calls after vectorizer
has a chance to optimize loop, specially when vectorized version
of built-in function is not available.
As this is canonicalization fold does, there is no chance for doing so.
Now, this is again a reason to look at item #<high number> of my todo
list that says 'add POW tree-code', which would make this and other