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Re: Constant folding and Constant propagation

From: Daniel Jacobowitz <drow at false dot org>
To: Jean Christophe Beyler <jean dot christophe dot beyler at gmail dot com>
Cc: Ian Lance Taylor <iant at google dot com>, gcc at gcc dot gnu dot org
Date: Fri, 6 Feb 2009 12:04:20 -0500
Subject: Re: Constant folding and Constant propagation
References: <c568a2600902051234i35e77cebu23db6d54c7a0743a@mail.gmail.com> <m3eiyca8tw.fsf@google.com> <c568a2600902060846o13d075d6n717938f1955f218a@mail.gmail.com>

On Fri, Feb 06, 2009 at 11:46:58AM -0500, Jean Christophe Beyler wrote:
> I finally get this :
> 
> (const_int 51966 [0xcafe])
> (const_int 51966 [0xcafe])
> (const_int 51971 [0xcb03])
> (const_int 51971 [0xcb03])
> 
> All of these have an outer code of SET. Therefore, I'm not quite
> positive of how I'm supposed to implement my rtx_cost function. Since
> I don't seem to get a choice between a set 0xcb03 and a (plus 0xcafe
> 5), how can I tell the compiler the different costs?

They may all have an outer code of SET, but you get the entire inner
RTX.  Search arm_rtx_costs_1 for "CONST_INT:".

-- 
Daniel Jacobowitz
CodeSourcery

References:
- Constant folding and Constant propagation
  - From: Jean Christophe Beyler
- Re: Constant folding and Constant propagation
  - From: Ian Lance Taylor
- Re: Constant folding and Constant propagation
  - From: Jean Christophe Beyler

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