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Added support for MACRO-10 literal collapsing; it's not super-aggressive, but it's more than adequate for what DEC's diagnostics require

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Jeff 2017-03-28 15:22:17 -07:00 • committed by Jeff Parsons
commit d5c48df9bc
10 changed files with 1242 additions and 1144 deletions
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1868
modules/pdp10/lib/cpuops.js
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82
modules/pdp10/lib/macro10.js
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@ -378,19 +378,70 @@ class Macro10 {
this.error("open scope from line " + this.stackScopes[0].nLine);
}
for (let i = 0; i < this.aLiterals.length; i++) {
let lit = this.aLiterals[i];
this.addSymbol(lit.name, this.nLocation, Macro10.SYMTYPE.LABEL);
lit.aWords.forEach(function(w, nLocation) {
macro10.genWord(w, lit.aFixups[nLocation]);
});
let nLocationLiterals = this.nLocation;
for (let i = 0; i < this.aLiterals.length; i++) {
/*
* TODO: Add support for "literal collapsing"; ie, if two or more literals generate the same
* set of values, then all instances after the first should refer back to the first (subject to
* exceptions identified by MACRO-10: eg, "literals that contain errors, undefined expressions,
* or EXTERNAL symbols.")
* Apparently, the time has come to implement "literal collapsing"; I was treating it as just
* a nice optimization, but it turns out that DEC has written tests that actually DEPEND on it:
*
* C26300: HRRZI [135531,,246642] ;PRELOAD AC0 WITH 0,, LITERAL ADDRESS
* JRA .+1 ;*JRA SHOULD PLACE C(AC0) INTO AC0
* CAIE [135531,,246642] ;PASS IF JRA PLACED C(AC0) INTO AC0
* STOP
*
* If the HRRZI and CAIE instructions don't refer to the same exact literal, the test will fail.
* For purposes of this particular test, the values they stuffed into the literals are essentially
* gibberish, but the same literal may be used in another test where the values are significant.
*
* However, I'm still going to keep it simple. In this example from p. 2-8 of the April 1978
* MACRO-10 manual, I will NOT be attempting to collapse null words at the end of ASCIZ sequences
* with other null words, especially if they were defined before the ASCIZ:
*
* Literals having the same value are collapsed in MACRO's literal pool.
* Thus for the statements:
*
* PUSH P,[0]
* PUSH P,[0]
* MOVEI 1,[ASCIZ /TEST1/]
*
* the same address is shared by the two literals [0], and by the null word
* generated at the end of [ASCIZ /TEST1/].
*/
let lit = this.aLiterals[i];
/*
* First things first: verify that the literal is one contiguous set of words (I'm not sure how
* it couldn't be, but better safe than sorry).
*/
let aWords = [];
let nWords = 0;
lit.aWords.forEach(function(w, nLocation) {
if (nLocation === aWords.length) aWords.push(w);
nWords++;
});
if (nWords == aWords.length) {
/*
* So far, so good. Now we'll simply brute-force-search our way through the existing set of
* literals, looking for a complete match.
*/
for (let nLocation = nLocationLiterals; nLocation + nWords <= this.nLocation; nLocation++) {
let n;
for (n = 0; n < nWords; n++) {
if (aWords[n] !== this.aWords[nLocation + n] || lit.aFixups[n] != this.aFixups[nLocation]) break;
}
if (n == nWords) {
this.addSymbol(lit.name, nLocation, Macro10.SYMTYPE.LABEL);
lit = null;
break;
}
}
}
if (lit) {
this.addSymbol(lit.name, this.nLocation, Macro10.SYMTYPE.LABEL);
lit.aWords.forEach(function(w, nLocation) {
macro10.genWord(w, lit.aFixups[nLocation]);
});
}
}
for (let i = 0; i < this.aVariables.length; i++) {
@ -701,9 +752,14 @@ class Macro10 {
*/
pushScope(name)
{
this.stackScopes.push(
{name, aWords: this.aWords, aFixups: this.aFixups, nLocation: this.nLocation, nLocationScope: this.nLocationScope, nLine: this.nLine}
);
this.stackScopes.push({
name,
aWords: this.aWords,
aFixups: this.aFixups,
nLocation: this.nLocation,
nLocationScope: this.nLocationScope,
nLine: this.nLine
});
this.aWords = [];
this.aFixups = [];
this.nLocationScope = this.nLocation;