Alright, Levente! Thank you so very much! You are a generous soul & an angel! Your suggestions (the first two) worked like a charm and I have a running plugin to GF arithmetic, GFPoly arithmetic and RSDecoder arithmetic {#findErrorLocation: & #findErrorMagnitudes:errorLocations:} both plugganized. The cumulative speedup is 568% and all the hotspots changed again.

I tried to implement GFPoly>>#initializeField:coefficients: in a plugin function, but my image is crashing on startup, when standard GFs are created in GF class>>#startUp:, when each GF initializes it attempts to create a one and a zero polynomial. This would call the primitive for #initializePoly. This code can be seen in the package: CryptographyRSFECPluginsInitializeGFPoly. I am attempting to run:

            (firstNonZero > coefficientsLength)
                ifTrue: [
                        mutableCoefficients := interpreterProxy
                            instantiateClass: interpreterProxy classByteArray
                            indexableSize: 1]
                ifFalse: [
                        mutableCoefficients := interpreterProxy
                            instantiateClass: interpreterProxy classByteArray
                            indexableSize: (coefficientsLength - firstNonZero + 1).

The cumulative speedup is 568% and all the hotspots changed again. Here are the profiling results from just the RSFEC code alone, no RSErasure code is in the profiles. The new hotspots are, with RSFECPlugin, then without.

((128683 / 22648) asFloat * 100) asInteger = 568%

The remaining potential plugganization relates to complex object instantiation inside the plugin functions. {#decode:twoS:, #runEuclideanAlgorithm: and #initializeField:coefficients:}. The best value for work return is to plugganize #initializeField:coefficients: at 3.3 seconds (14%)

WITH GF & GFPOLY PRIMITIVES AND DECODER PRIMITIVES
(3 asterix for in-progress plugganization)

 - 22194 tallies, 22648 msec.

**Leaves**
29.1% {6586ms} RSFECDecoderWithPlugin>>decode:twoS:
14.7% {3329ms} RSFECGenericGFPoly class>>newField:coefficients:
7.3% {1646ms} RSFECDecoderWithPlugin>>primFindErrorLocationsDegree:coefficients:result:fieldSize:
2.9% {654ms} RSFECDecoderWithPlugin>>findErrorMagnitudes:errorLocations:
1.0% {237ms} RSFECDecoderWithPlugin>>runEuclideanAlgorithmPoly:poly:rDegrees:

Calls to plugganized GF/GFPoly methods:

1.4% {317ms} RSFECGenericGFWithPlugin>>log:

And:

WITHOUT GF & GFPOLY PRIMITIVES - NO RSFEC PRIMITIVES

- 98352 tallies, 128683 msec.

**Leaves**
GF arithmetic
23.4% {30126ms} RSFECGenericGF>>exp:
13.4% {17229ms} RSFECGenericGF>>addOrSubtract:by:
11.9% {15251ms} RSFECGenericGF>>maskValue:
10.0% {12916ms} RSFECGenericGF>>log:
8.6% {11059ms} RSFECGenericGF>>normalizeIndex:
6.8% {8792ms} RSFECGenericGF>>multiply:by:
GFPoly arithmetic
2.7% {3529ms} RSFECGenericGFPoly>>evaluateAt:
2.1% {2715ms} RSFECGenericGFPoly>>addOrSubtractPoly:
2.0% {2578ms} RSFECGenericGFPoly>>multiplyByMonomialDegree:coefficient:

Hi Robert,

I see the following potential causes:

In #findErrorLocationsDegree:coefficients:count:fieldSize:result: the
return value in ambiguous. You make the primitive fail if not enough
errors are found. But after the send, you don't check for failure
but simply send #methodReturnReceiver.
Instead, you should either check for primitive failure after the send
or make #findErrorLocationsDegree:coefficients:count:fieldSize:result:
return boolean value: the method was successful or not.
E.g. when numErrors = 1, return true, in the other branch, return e =
numErrors. (If slang doesn't support boolean types, just use 0 and 1).
In the actual primitive method, check for the value returned by that
method and fail the primitive when needed. Once the primitive has failed,
you ought to return from it.
I see the above pattern in other methods too (marking the primitive as
failed in a not-top-level method without checking for failure outside).
Those need to be fixed as well.

Another potential issue I see is that the validation of the arguments is
not complete.
E.g.: #stackIntegerValue: may have already set the primitive to failed if
the argument was not an integer. So, before continuing, that has to be
checked.

Another possible but unlikely problem is that you assume that both result
and coefficients have at least one field. But that may not be true which
can result in segfaults.


Levente