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Re: IF conversion bug with CC0
- From: Dan <dgisselq at verizon dot net>
- To: Eric Botcazou <ebotcazou at adacore dot com>
- Cc: dgisselq at ieee dot org, gcc at gcc dot gnu dot org, Jeff Law <law at redhat dot com>
- Date: Mon, 04 Apr 2016 20:04:10 -0400
- Subject: Re: IF conversion bug with CC0
- Authentication-results: sourceware.org; auth=none
- References: <1459801150 dot 1603 dot 51 dot camel at jericho> <5702EB7C dot 2090404 at redhat dot com> <1459810149 dot 1603 dot 59 dot camel at jericho> <2272470 dot OBZZDVXS4c at polaris>
- Reply-to: dgisselq at ieee dot org
Got it! That even answers my second round of questions.
On Tue, 2016-04-05 at 01:24 +0200, Eric Botcazou wrote:
> > I took a quick look at Visium, and noticed arithmetic instructions in
> > the .md file doing a lot of clobbering of the condition codes register.
> > This doesn't seem very efficient, since it prevents the arithmetic
> > instructions from being able to set the CC register and have that value
> > be used.
> See the define_subst patterns, they automatically compute the other form.