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Re: Identifying a block copy

From: "Pranav Bhandarkar" <pranav dot bhandarkar at gmail dot com>
To: "Daniel Berlin" <dberlin at dberlin dot org>
Cc: gcc at gnu dot org
Date: Tue, 9 Oct 2007 19:09:10 +0530
Subject: Re: Identifying a block copy
References: <649555d50710090053w3b24b2b6n7217a96705d19ec9@mail.gmail.com> <4aca3dc20710090538t3a63ab91u32e4300adf3dc368@mail.gmail.com>

On 10/9/07, Daniel Berlin <dberlin@dberlin.org> wrote:
> Yes
> we do not create subvars for non-named memory locations.  IE random
> pointer dereferences.
>
> This is mainly because it would require a lot of time and memory in
> the compiler.
>
> It was done because most optimizers rely solely on vdef/vuses, instead
> of further disambiguating the memory dependence chains.

ok, makes sense.

> In any case, it's not clear why you care about subvars at all here.
> If you want to identify block copies, simply look for assignments
> between AGGREGATE_TYPE_P trees.

Aha, this would be neater.

Thanks for pointing me in the right direction.

cheers!
Pranav

References:
- Identifying a block copy
  - From: Pranav Bhandarkar
- Re: Identifying a block copy
  - From: Daniel Berlin

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