Return-Path: Subject: Re: [PATCH] SBC encoder scale factors calculation optimized with __builtin_clz From: Marcel Holtmann To: Siarhei Siamashka Cc: linux-bluetooth@vger.kernel.org In-Reply-To: <200901290310.03440.siarhei.siamashka@nokia.com> References: <200901290310.03440.siarhei.siamashka@nokia.com> Content-Type: text/plain Date: Thu, 29 Jan 2009 08:27:38 +0100 Message-Id: <1233214058.2139.6.camel@violet> Mime-Version: 1.0 Sender: linux-bluetooth-owner@vger.kernel.org List-ID: Hi Siarhei, > The attached patch contains optimization for scale factors calculation which > provides additional SBC encoder speedup. > > For non-gcc compilers, CLZ function is implemented with a very simple and > slow straightforward code (but it is still faster than current git code even > if used instead of __builtin_clz). Something better could be done like: > http://groups.google.com/group/comp.sys.arm/msg/5ae56e3a95a2345e?hl=en > But I'm not sure about license/copyright of the code at this link and decided > not to touch it. Anyway, I don't think that gcc implementation of > __builtin_clz for the CPU cores which do not support CLZ instruction is any > worse. personally I don't really care about non-gcc compilers. I think that some of the BlueZ source might not even compile without gcc. Anyway, patch has been applied. Thanks. Regards Marcel