Floating point on IBM PPC405 (266MHz)

Yes. PPC405GPr.

Yes, because the PPC405 has no floating point support.

Hope that helps JB

In any case, you should make sure you are using a proper toolchain that does not generate floating point instructions (ie. implies a -fsoft-float). These can be handled by the kernel's math emulation, but this will slow things down even more.

Regards, Marius.

-- Marius Groeger SYSGO Real-Time Solutions GmbH

We're using the PPC405, too. I never got the kernel's floating point emulation to work, so we're 100% soft-float. I have a toolchain build script at

- Dan

Well, compared to kernel emulation it doesn't suck. It would suck to have to trap every time you needed to emulate a FP instruction. :)

If somebody needs good FP performance on 4xx then they could buy (in huge volume) a 405+FPU ASSP/CSSP like one company I've heard of or get the announced 440EP (that has the FPU macro cell).

-Matt

I'm asking because I have QNX (6.2.1a) running on this baby and it's extreamly slow with floating point stuff, so I was wondering if anyone could help me check the performance on linux ( I'm trying to convice our client to switch to linux )...

I'm also dissapointed of the integer performance too... On a StrongARM 1110 (

Is anyone willing to run this test on PPC405 with linux (it's very simple. I'll send you the source.)?

Best Regards,

send you the

Ok. Send me the code. I need some stress test...