Question about comment in arm_legitimize_address()

Richard Earnshaw Richard.Earnshaw@arm.com
Wed Oct 20 10:53:00 GMT 2004


 

> -----Original Message-----
> From: Ian Lance Taylor [mailto:ian@wasabisystems.com] 
> Sent: 19 October 2004 19:43
> To: rearnshaw@arm.com
> Cc: gcc@gcc.gnu.org
> Subject: Question about comment in arm_legitimize_address()
> 
> In the function thumb_legitimize_address() I see this:
> 
>       /* Try and fold the offset into a biasing of the base 
> register and
> 	 then offsetting that.  Don't do this when optimizing for space
> 	 since it can cause too many CSEs.  */
>       if (optimize_size && offset >= 0
> 	  && offset < 256 + 31 * GET_MODE_SIZE (mode))
> 
> The comment says don't do it when optimizing for space.  The code says
> to do it only when optimizing for space.  You added the function here:
>     http://gcc.gnu.org/ml/gcc-patches/2004-02/msg02380.html
> 
> Which is correct?  The comment or the code?
> 
> Ian
> 

I think the comment is probably correct, but the code shouldn't be
changed without first validating it with something like the CSiBE
benchmark.

R.



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