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Re: [Discuss-gnuradio] 64 bit
From: |
Matt Ettus |
Subject: |
Re: [Discuss-gnuradio] 64 bit |
Date: |
Fri, 16 Dec 2005 15:20:06 -0800 |
User-agent: |
Mozilla Thunderbird 1.0.7-1.1.fc4 (X11/20050929) |
> The noise source is pretty expensive, particularly for GR_GAUSSIAN.
> Also, you're using the generic fir filter kernel (straight C++). On
> x86 and x86-64 we've got hand-coded assembler for taking advantage of
> SSE and 3DNow SIMD instructions.
The noise source is very expensive. We should find some alternative
implementation which is faster.
> I don't know if there's a Solaris equivalent to "oprofile" (profiling
> using the h/w performance counters), but the first step to making it
> faster would be to determine where it's slow.
As a former UltraSPARC designer, I can give the following advice --
- Floating point is much better than integer math
- VIS (Visual Instruction Set) is a big help. VIS is the SPARC
equivalent of MMX and SSE. Actually, VIS came first, so you could argue
that MMX is a clone of VIS :)
You also need to keep in mind that you can't get blood from a stone.
The UltraSPARC II was a great processor for its day, but it's about 9
years old now.
Matt