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Re: cc register usage on i386/2.96
- To: ak at suse dot de, gcc at gcc dot gnu dot org
- Subject: Re: cc register usage on i386/2.96
- From: Jan Hubicka <jh at suse dot cz>
- Date: Mon, 28 Aug 2000 01:51:05 +0200
> Hallo,
>
> gcc 2.96 seems to have lost the ability to directly use the condition
> code generated by arithmetic instructions (like add or or). It always inserts
> an redundant testl in my tests. According to a comment in i386.c it shoul
2.96 should be able to do so, but do use completely new mechanizm for it, so it
is quite possible that some cases has been left out. Can you send me your
testcases?
> only do that during the reload pass, because reload does not seem to know
Currently the combine pass is responsible for combining the comparison together
with the arithmetic when possible. It does not get all cases, but should
do so in most of them.
Honza
> about cc, but it seems to do that always. Is there any chance to restore
> that capability ?
>
> -Andi
>