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RE: h8300-hms: Use hardware multiply for ___mulsi3
- From: Kazu Hirata <kazu at hxi dot com>
- To: 'tm' <tm at mail dot kloo dot net>, gcc-patches at gcc dot gnu dot org
- Cc: toshiyasu dot morita at hsa dot hitachi dot com, tm at kloo dot net
- Date: Sat, 20 Apr 2002 14:01:35 -0400
- Subject: RE: h8300-hms: Use hardware multiply for ___mulsi3
Hi Toshi,
> The present implementation of ___mulsi3 uses a shift-and-add scheme
> which is agonizingly slow.
>
> This patch modifies ___mulsi3 to use 3 16x16 multiplies which improves
> worst-case timing significantly.
>
> Kazu: can you test throughly and make sure it's correct?
>
> Toshi
>
> 2002-03-27 Toshiyasu Morita <toshiyasu.morita@hsa.hitachi.com>
>
> * config/h8300/lib1funcs.asm (___mulsi3): Use hardware
> multiply instructions for H8/300H case.
Thanks! Installed.
Kazu Hirata