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Re: [PATCH 204/236] final.c: Use rtx_sequence


On Fri, Aug 15, 2014 at 04:24:49PM -0600, Jeff Law wrote:
> On 08/06/14 11:23, David Malcolm wrote:
> >gcc/
> >	* final.c (get_attr_length_1): Replace GET_CODE check with a
> >	dyn_cast, introducing local "seq" and the use of methods of
> >	rtx_sequence.
> >	(shorten_branches): Likewise, introducing local "body_seq".
> >	Strengthen local "inner_insn" from rtx to rtx_insn *.
> >	(reemit_insn_block_notes): Replace GET_CODE check with a
> >	dyn_cast, strengthening local "body" from rtx to rtx_sequence *.
> >	Use methods of rtx_sequence.
> >	(final_scan_insn): Likewise, introducing local "seq" for when
> >	"body" is known to be a SEQUENCE, using its methods.
> So presumably a dyn_cast isn't terribly expensive here?  I guess I'm a bit
> fuzzy on whether or not we agreed to allow using dynamic casts?!? Doesn't
> that have to check the RTTI info which I would think would be considerably
> more expensive than just checking the code.  Or am I missing something here?

 your missing dyn_cast != dynamic_cast, the first is just a wrapper
 around as_a / is_a, and so doesn't use rtti.

Trev

> 
> Jeff
> 


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