>-- Original Message -- >Subject: RE: Doing floating point calculations in kernel space >From: Toni Van Remortel <t.vanremortel at ha.be> >Reply-To: t.vanremortel at ha.be >To: Wolfgang Grandegger <wolfgang.grandegger at bluewin.ch> >Cc: Linuxppc-Embedded <linuxppc-embedded at lists.linuxppc.org> >Date: Fri, 17 Oct 2003 10:59:29 +0200 > > >Op vr 17-10-2003, om 09:52 schreef Toni Van Remortel: >> Op vr 17-10-2003, om 09:33 schreef Wolfgang Grandegger: >> > ftp://ftp.denx.de/pub/RTAI/contrib/fp_ppc_8xx.tar.bz2 >> > It links statically with the libm and the soft-float >> > library derived from libgcc. >> > >> > Hope it's useful. >> >> Seems useful. Let's check it out deeper and implement it into my module. >> I'll keep you informed. > >It compiles, it runs. Very nice. Thank you a lot for the example. I had >only to add the extra linking to my compile command.
Unfortunately, this soft-float implementation from GCC is very very slow :-(. I'm just doing some benchmarking with soft-float on IBM 405 and compare the result with the soft-float library provided by VxWorks. And a simple add (__adddf3) is approx. 5 times faster on VxWorks. And a look to the assembler code makes clear why. Has anybody else on this list made similar experience or it there a better free implementation? Has this been improved in GCC >= 3.2. Thanks. Wolfgang. Wolfgang ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
