[libre-riscv-dev] [Bug 286] DataPointer concept: long-immediate references

bugzilla-daemon at libre-soc.org bugzilla-daemon at libre-soc.org
Wed Apr 15 20:22:38 BST 2020


--- Comment #6 from Luke Kenneth Casson Leighton <lkcl at lkcl.net> ---
(In reply to Jacob Lifshay from comment #5)
> (In reply to Luke Kenneth Casson Leighton from comment #4)
> >   particularly as a reduction in i-cache
> > size obeys a square law reduction in power consumption.
> I would expect the cache power usage to be linearly proportional to it's
> size in bits once it's big enough to split into many smaller sram chunks,
> since each sram chunk would use about the same power and you'd only need a
> linear number of them.

whilst the cache power usage itself is linear (that being one dimension
of the square effect), the increased size means that on loops you cannot
fit as much code of the average loop *into* that cache, meaning that you
end up with more L2 cache lookups.  this i believe is where the 2nd of
the two dimensions of the square effect comes in.

it's quite... odd :)

You are receiving this mail because:
You are on the CC list for the bug.

More information about the libre-riscv-dev mailing list