[Bf-committers] How about adding boost uBLAS library toblender/extern?

Timothy Baldridge tbaldridge at gmail.com
Mon Jan 26 16:18:58 CET 2009

> According to a Prof. of mine[1] loading/storing from/to SIMD registers is in
> fact slow and should be avoided.

That would be a assumption that I would consider do be dangerous to assume.

I once benchmarked the difference in using standard 32-bit registers
for copying data from one portion of memory (64MB chunk). The standard
registers clocked in at about 2GB/sec while I hit almost 12GB/sec
using 4x SIMD registers as I could load 128 bits at once.

Now what your prof probably said was that it was slower to load a
128bit register than a 32bit register so you shouldn't use SSE unless
you are doing SIMD. So in this case, we want to use SIMD as we are
working with 3-4 32bit floats that will just "happen" to fit perfectly
in a 128bit SIMD register.


"One of the main causes of the fall of the Roman Empire was
that–lacking zero–they had no way to indicate successful termination
of their C programs."
(Robert Firth)

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