There is a list at the end of opcodes.h, which alas is pretty long despite its (mis)leading comment:
/*
special classes:
Object, List, Number, Int, Float, Signal, Complex, Point
*/
enum {
op_class_object,
op_class_symbol,
op_class_nil,
op_class_boolean,
op_class_true,
op_class_false,
op_class_magnitude,
op_class_char,
op_class_number,
op_class_complex,
op_class_simple_number,
op_class_int,
op_class_float,
op_class_method,
op_class_fundef,
op_class_stream,
op_class_func,
op_class_frame,
op_class_process,
op_class_main,
op_class_class,
op_class_string,
op_class_collection,
op_class_sequenceable_collection,
op_class_arrayed_collection,
op_class_array,
op_class_int8array,
op_class_int16array,
op_class_int32array,
op_class_floatarray,
op_class_signal,
op_class_doublearray,
op_class_symbolarray,
op_class_list,
op_class_linkedlist,
op_class_bag,
op_class_set,
op_class_identityset,
op_class_dictionary,
op_class_identitydictionary,
op_class_sortedlist,
op_class_synth,
op_class_ref,
op_class_environment,
op_class_event,
op_class_wavetable,
op_class_env,
op_class_routine,
op_class_color,
op_class_rect,
op_NumSpecialClasses
};
But it’s not terribly clear to me which of those “special” classes are actually unboxed…
However since Synth is on that specials list, for practical purposes it means that you have to (pre)compile most of the library in order for it to “work”, in the sense of not crashing the VM by accessing unloaded classes. I mean, other Smalltalk derivatives manage dynamic class loading (from user classes), but probably have a less extensive list of “specials”. Now even for SC, after the “monster classlib” is loaded, there’s no apriori reason you could not load more classes, as far those specials are concerned…
As far as devirtualization goes, there are a bunch “special selectors”, actually put in 3 different tables in the header file (unary, binary, and the rest), but initialized all in one method in PyrParseNode.cpp
void initSpecialSelectors() {
PyrSymbol** sel;
long i;
sel = gSpecialUnarySelectors;
sel[opNeg] = getsym("neg");
sel[opRecip] = getsym("reciprocal");
sel[opNot] = getsym("not");
sel[opIsNil] = getsym("isNil");
sel[opNotNil] = getsym("notNil");
sel[opBitNot] = getsym("bitNot");
sel[opAbs] = getsym("abs");
sel[opAsFloat] = getsym("asFloat");
sel[opAsInteger] = getsym("asInteger");
sel[opCeil] = getsym("ceil"); // 5
sel[opFloor] = getsym("floor");
sel[opFrac] = getsym("frac");
sel[opSign] = getsym("sign");
sel[opSquared] = getsym("squared");
sel[opCubed] = getsym("cubed"); // 10
sel[opSqrt] = getsym("sqrt");
sel[opExp] = getsym("exp");
sel[opMIDICPS] = getsym("midicps");
sel[opCPSMIDI] = getsym("cpsmidi");
sel[opMIDIRatio] = getsym("midiratio");
sel[opRatioMIDI] = getsym("ratiomidi");
sel[opAmpDb] = getsym("ampdb"); // 15
sel[opDbAmp] = getsym("dbamp");
sel[opOctCPS] = getsym("octcps");
sel[opCPSOct] = getsym("cpsoct");
sel[opLog] = getsym("log");
sel[opLog2] = getsym("log2"); // 20
sel[opLog10] = getsym("log10");
sel[opSin] = getsym("sin");
sel[opCos] = getsym("cos");
sel[opTan] = getsym("tan");
sel[opArcSin] = getsym("asin"); // 25
sel[opArcCos] = getsym("acos");
sel[opArcTan] = getsym("atan");
sel[opSinH] = getsym("sinh");
sel[opCosH] = getsym("cosh");
sel[opTanH] = getsym("tanh"); // 30
sel[opRand] = getsym("rand");
sel[opRand2] = getsym("rand2");
sel[opLinRand] = getsym("linrand");
sel[opBiLinRand] = getsym("bilinrand");
sel[opSum3Rand] = getsym("sum3rand");
/*
sel[opExpRand] = getsym("exprand");
sel[opBiExpRand] = getsym("biexprand");
sel[opGammaRand] = getsym("gammarand");
sel[opGaussRand] = getsym("gaussrand");
sel[opPoiRand] = getsym("poirand");
*/
sel[opDistort] = getsym("distort");
sel[opSoftClip] = getsym("softclip");
sel[opCoin] = getsym("coin");
sel[opRectWindow] = getsym("rectWindow");
sel[opHanWindow] = getsym("hanWindow");
sel[opWelchWindow] = getsym("welWindow");
sel[opTriWindow] = getsym("triWindow");
sel[opSCurve] = getsym("scurve");
sel[opRamp] = getsym("ramp");
sel[opDigitValue] = getsym("digitValue");
sel[opSilence] = getsym("silence");
sel[opThru] = getsym("thru");
sel = gSpecialBinarySelectors;
sel[opAdd] = getsym("+");
sel[opSub] = getsym("-");
sel[opMul] = getsym("*");
sel[opFDiv] = getsym("/");
sel[opIDiv] = getsym("div");
sel[opMod] = getsym("mod");
sel[opEQ] = getsym("==");
sel[opNE] = getsym("!=");
sel[opLT] = getsym("<");
sel[opGT] = getsym(">");
sel[opLE] = getsym("<=");
sel[opGE] = getsym(">=");
// sel[opIdentical] = getsym("===");
// sel[opNotIdentical] = getsym("!==");
sel[opMin] = getsym("min");
sel[opMax] = getsym("max");
sel[opBitAnd] = getsym("bitAnd");
sel[opBitOr] = getsym("bitOr");
sel[opBitXor] = getsym("bitXor");
sel[opLCM] = getsym("lcm");
sel[opGCD] = getsym("gcd");
sel[opRound] = getsym("round");
sel[opRoundUp] = getsym("roundUp");
sel[opTrunc] = getsym("trunc");
sel[opAtan2] = getsym("atan2");
sel[opHypot] = getsym("hypot");
sel[opHypotx] = getsym("hypotApx");
sel[opPow] = getsym("pow");
sel[opShiftLeft] = getsym("leftShift");
sel[opShiftRight] = getsym("rightShift");
sel[opUnsignedShift] = getsym("unsignedRightShift");
sel[opFill] = getsym("fill");
sel[opRing1] = getsym("ring1"); // a * (b + 1) == a * b + a
sel[opRing2] = getsym("ring2"); // a * b + a + b
sel[opRing3] = getsym("ring3"); // a*a*b
sel[opRing4] = getsym("ring4"); // a*a*b - a*b*b
sel[opDifSqr] = getsym("difsqr"); // a*a - b*b
sel[opSumSqr] = getsym("sumsqr"); // a*a + b*b
sel[opSqrSum] = getsym("sqrsum"); // (a + b)^2
sel[opSqrDif] = getsym("sqrdif"); // (a - b)^2
sel[opAbsDif] = getsym("absdif"); //
sel[opThresh] = getsym("thresh"); //
sel[opAMClip] = getsym("amclip"); //
sel[opScaleNeg] = getsym("scaleneg"); //
sel[opClip2] = getsym("clip2");
sel[opFold2] = getsym("fold2");
sel[opWrap2] = getsym("wrap2");
sel[opExcess] = getsym("excess");
sel[opFirstArg] = getsym("firstArg");
sel[opRandRange] = getsym("rrand");
sel[opExpRandRange] = getsym("exprand");
sel = gSpecialSelectors;
sel[opmNew] = getsym("new");
sel[opmNewClear] = getsym("newClear");
sel[opmNewCopyArgs] = getsym("newCopyArgs");
sel[opmInit] = getsym("init");
sel[opmAt] = getsym("at");
sel[opmPut] = getsym("put");
sel[opmNext] = getsym("next");
sel[opmReset] = getsym("reset");
sel[opmValue] = getsym("value");
sel[opmCopyToEnd] = getsym("copyToEnd"); // used by multiple assignment
// sel[opmIsNil] = getsym("isNil");
// sel[opmNotNil] = getsym("notNil");
sel[opmSize] = getsym("size");
sel[opmClass] = getsym("class");
sel[opmIf] = getsym("if");
sel[opmWhile] = getsym("while");
sel[opmFor] = getsym("for");
sel[opmAnd] = getsym("and");
sel[opmOr] = getsym("or");
sel[opmCase] = getsym("case");
sel[opmSwitch] = getsym("switch");
sel[opmIdentical] = getsym("===");
sel[opmNotIdentical] = getsym("!==");
sel[opmPrint] = getsym("print");
sel[opmAdd] = getsym("add");
sel[opmRemove] = getsym("remove");
sel[opmIndexOf] = getsym("indexOf");
sel[opmWrapAt] = getsym("wrapAt");
sel[opmClipAt] = getsym("clipAt");
sel[opmFoldAt] = getsym("foldAt");
sel[opmWrapPut] = getsym("wrapPut");
sel[opmClipPut] = getsym("clipPut");
sel[opmFoldPut] = getsym("foldPut");
sel[opmDo] = getsym("do");
sel[opmCollect] = getsym("collect");
sel[opmSelect] = getsym("select");
sel[opmReject] = getsym("reject");
sel[opmAny] = getsym("any");
sel[opmEvery] = getsym("every");
sel[opmFind] = getsym("find");
sel[opmChoose] = getsym("choose");
sel[opmValueList] = getsym("valueList");
sel[opmAddFirst] = getsym("addFirst");
sel[opmPrimitiveFailed] = getsym("primitiveFailed");
sel[opmSubclassResponsibility] = getsym("subclassResponsibility");
sel[opmShouldNotImplement] = getsym("shouldNotImplement");
sel[opmDoesNotUnderstand] = getsym("doesNotUnderstand"); // not really needed
sel[opmNotYetImplemented] = getsym("notYetImplemented");
sel[opmAtSign] = getsym("@");
sel[opmWrapAtSign] = getsym("@@");
sel[opmClipAtSign] = getsym("|@|");
sel[opmFoldAtSign] = getsym("@|@");
sel[opmMultiNew] = getsym("multiNew"); // UGens
sel[opmMultiNewList] = getsym("multiNewList"); // UGens
sel[opmAR] = getsym("ar"); // UGens
sel[opmKR] = getsym("kr"); // UGens
sel[opmIR] = getsym("ir"); // UGens
sel[opmEnvirGet] = getsym("envirGet");
sel[opmEnvirPut] = getsym("envirPut");
sel[opmHalt] = getsym("halt");
sel[opmForBy] = getsym("forBy");
sel[opmForSeries] = getsym("forSeries");
sel[opmReverseDo] = getsym("reverseDo");
sel[opmLoop] = getsym("loop");
sel[opmNonBooleanError] = getsym("mustBeBoolean");
sel[opmCopy] = getsym("copy");
sel[opmPerformList] = getsym("performList");
sel[opmIsKindOf] = getsym("isKindOf");
sel[opmPostln] = getsym("postln");
sel[opmAsString] = getsym("asString");
sel[opmPlusPlus] = getsym("++");
sel[opmLTLT] = getsym("<<");
sel[opmQuestionMark] = getsym("?");
sel[opmDoubleQuestionMark] = getsym("??");
sel[opmExclamationQuestionMark] = getsym("!?");
sel[opmYield] = getsym("yield");
sel[opmName] = getsym("name");
sel[opmMulAdd] = getsym("madd");
sel[opmSeries] = getsym("series");
for (i = 0; i < opNumUnarySelectors; ++i) {
gSpecialUnarySelectors[i]->specialIndex = i;
}
for (i = 0; i < opNumBinarySelectors; ++i) {
gSpecialBinarySelectors[i]->specialIndex = i;
}
}
Now, the fact a selector is on that list, doesn’t necessarily mean it’s devirtualized, but often enough it is. E.g. when (even user-subclassed) Environments are accessed, the calls to envirGet and envirPut (which do appear in that specials list) are devirtualized by default.
On the other hand, there does not seem to a generalized devirtualization process for stuff in the classlib, i.e. besides what’s baked into the specials’ implementations.
Side note: in GHC (Haskell) you can access the unboxed types with the “magic hash” extension, but even there, you cannot pass unboxed types to polymorphic functions.