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Re: IF conversion bug with CC0
- From: Eric Botcazou <ebotcazou at adacore dot com>
- To: Jeff Law <law at redhat dot com>
- Cc: gcc at gcc dot gnu dot org, dgisselq at ieee dot org
- Date: Tue, 05 Apr 2016 00:20:08 +0200
- Subject: Re: IF conversion bug with CC0
- Authentication-results: sourceware.org; auth=none
- References: <1459801150 dot 1603 dot 51 dot camel at jericho> <1459804405 dot 1603 dot 55 dot camel at jericho> <5702DBDB dot 7080102 at redhat dot com>
> From a 30 second view of your ISA, it appears that most
> arithmetic/logicals unconditionally set the condition codes.
> I would suggest modeling condition code handling similar to how it's
> done on the x86 port.
No advertisement intended, but the Visium architecture is the typical 32-bit
RISC where every single arithmetic/logical unconditionally sets the condition
code. Moreover, the port was very recently converted from CC0 to CCmode (with
uniform post-reload splitters and define_substs tailored for the postreload
compare elimination pass), so it could be a good model.