This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: GCC retargeting
- From: Jakub Jelinek <jakub at redhat dot com>
- To: Umesh Kalappa <umesh dot kalappa0 at gmail dot com>
- Cc: Paul_Koning at dell dot com, "gcc at gcc dot gnu dot org" <gcc at gcc dot gnu dot org>
- Date: Thu, 10 Oct 2013 13:38:36 +0200
- Subject: Re: GCC retargeting
- Authentication-results: sourceware.org; auth=none
- References: <CAGfacvRvgSnKPhMZ22JeffRT1hkzuO94tPkAQbajgx4-fNGzQw at mail dot gmail dot com> <C75A84166056C94F84D238A44AF9F6AD03709775 at AUSX10MPC103 dot AMER dot DELL dot COM> <CAGfacvSR9rpkDsGA5_JRCCFCDHM+QC4bfuRzaKJ+7SSOcRjOdA at mail dot gmail dot com>
- Reply-to: Jakub Jelinek <jakub at redhat dot com>
On Thu, Oct 10, 2013 at 04:48:05PM +0530, Umesh Kalappa wrote:
> where A has value oxff and B has value 0xee.
If the 16-bit registers overlap the 8-bit ones, then IMNSHO you don't
want to use different register numbers for the pairs, instead you just tell
GCC that HImode values must be put into even register numbers. So
you would have say (reg:QI 0 a), (reg:QI 1 b) and (reg:HI 0 a) where
the last one just would be printed as ab rather than a. You can find
many ports where register names differ depending on mode, including e.g.
i386; on say sparc the first 32 floating point registers can be used either
individually as SFmode (32-bit), or even pairs of them as DFmode (64-bit),
etc.
Jakub