[Libre-soc-bugs] [Bug 575] PartitionedEqGtLe needs to use RippleLSB

[bugzilla-daemon at libre-soc.org]

https://bugs.libre-soc.org/show_bug.cgi?id=575

Cesar Strauss <cestrauss at gmail.com> changed:

           What    |Removed                     |Added
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                 CC|                            |cestrauss at gmail.com

--- Comment #1 from Cesar Strauss <cestrauss at gmail.com> ---
(In reply to Luke Kenneth Casson Leighton from comment #0)
> output at present is either 0b0000 or 0b000001 in each partition (LSB is 1
> or 0), this needs to be 0b000000 or 0b111111 by using RippleLSB, initially.


This is not true anymore, it was changed in:

commit d07c689dc09ada1f3b408dcff9858b514a42dc80
Author: Michael Nolan <mtnolan2640 at gmail.com>
Date:   Fri Feb 7 09:29:32 2020 -0500

    modify reorder_bits to copy the MSB of the partition to each bit

    Previously, it would move the MSB to the LSB, and set the rest of the
    bits to 0.

 src/ieee754/part_cmp/reorder_results.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

It has become basically a "RippleMSB". Note that the previous stage
(GTCombiner) placed the result in the MSB.

> all documentation also needs updating to reflect this change.

There is a table here that needs updating:
https://libre-soc.org/3d_gpu/architecture/dynamic_simd/eq/

And another here:
https://libre-soc.org/3d_gpu/architecture/dynamic_simd/logicops/

The above page also has a textual description, that actually seems correct.

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