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Re: (R5900) Implementing Vector Support
- From: Woon yung Liu <ysai187 at yahoo dot com>
- To: Richard Henderson <rth at redhat dot com>, Gcc Mailing List <gcc at gcc dot gnu dot org>
- Date: Sat, 14 May 2016 10:21:50 +0000 (UTC)
- Subject: Re: (R5900) Implementing Vector Support
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- Reply-to: Woon yung Liu <ysai187 at yahoo dot com>
On Thursday, May 12, 2016 2:50 AM, Richard Henderson <email@example.com> wrote:
> Of course. They're used for different things. E.g.
> Yes I would think they should be expands. I would expect something like
Thank you for the sample code.
I'll be trying to implement those patterns, although I think that I will have to adjust the constraints and predicates again because the PMULTH instruction requires access to the whole LO and HI registers (0...128).
The current constraints allow GCC to access the 64-bit LO+HI register pair as a single 128-bit register, so I am cheating by using both the x and wr (new constraint for LO1+HI1) constraints.
Hopefully, the addition of such a multiplication pattern that involves parallel multiplication operations will not result in many more obscure problems. :/
Thanks and regards,