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fix(IRLower): memoize teardown routines, eliminate exponential codegen (54GB→3MB) #127

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Merged
egecanakincioglu merged 5 commits into from
May 31, 2026
Merged

fix(IRLower): memoize teardown routines, eliminate exponential codegen (54GB→3MB) #127

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a8cfdf3
fix(IRLower): memoize teardown routines, eliminate exponential codegen
egecanakincioglu May 31, 2026
23e4e03
debug: add Main.main() entry print
egecanakincioglu May 31, 2026
318feb9
debug: add more Main.main() trace prints
egecanakincioglu May 31, 2026
70e31c4
fix(IRLower): memoize teardown routines, eliminate exponential codegen
egecanakincioglu May 31, 2026
2786639
fix(IRLower): add Env.args()/Env.exePath() minimal stubs, prevent SIG…
egecanakincioglu May 31, 2026
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141 changes: 115 additions & 26 deletions arimo/compiler/backend/IRLower.arm
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Original file line number Diff line number Diff line change
Expand Up @@ -66,6 +66,7 @@ public class IRLower {
private classFldCounts : List<Integer>;
private methodRetNames : List<String>;
private methodRetClasses: List<String>;
private teardownLabels : List<String>;
private curClass : String;
private thisReg : String;
private linux : Boolean;
Expand Down Expand Up @@ -95,6 +96,7 @@ public class IRLower {
this.classFldCounts = List();
this.methodRetNames = List();
this.methodRetClasses = List();
this.teardownLabels = List();
this.curClass = "";
this.thisReg = "";
this.irFns.append(IRFunction("__placeholder", IRType.VOID));
Expand Down Expand Up @@ -135,6 +137,7 @@ public class IRLower {
this.classNames.append(cd.name);
this.classFldStarts.append(start);
this.classFldCounts.append(count);
this.teardownLabels.append("");
// Track parent class for recursive field release (inheritance chain)
if (cd.extends_ != "" && cd.extends_.length() > 0) {
this.classParents.append(this.classIdxOf(cd.extends_));
Expand Down Expand Up @@ -465,7 +468,7 @@ public class IRLower {
if (vci >= 0) {
String vr = this.varLookup(vn);
if (vr != "") {
this.emitRelease(IRValue.reg(vr, IRType.I64), vci, 0);
this.emitRelease(IRValue.reg(vr, IRType.I64), vci);
}
}
}
Expand Down Expand Up @@ -574,9 +577,96 @@ public class IRLower {
this.emit(IRInstr.label(nullSkipLbl));
}

// ===== Cached teardown routine generation =====

private needsTeardown(clsIdx: Integer) : Boolean {
Integer currIdx = clsIdx;
while (currIdx >= 0) {
Integer start = this.classFldStarts.get(currIdx) as Integer;
Integer count = this.classFldCounts.get(currIdx) as Integer;
Integer fi = 0;
while (fi < count) {
String fldCls = this.allFieldClasses.get(start + fi) as String;
if (this.classIdxOf(fldCls) >= 0) { return true; }
fi = fi + 1;
}
currIdx = this.classParents.get(currIdx) as Integer;
}
return false;
}

private emitTeardownBody(clsIdx: Integer) {
// obj parameter = first param (RDI on Linux, RCX on Windows)
IRValue objParam = IRValue.reg("obj", IRType.PTR);

Integer currIdx = clsIdx;
while (currIdx >= 0) {
Integer start = this.classFldStarts.get(currIdx) as Integer;
Integer count = this.classFldCounts.get(currIdx) as Integer;
Integer fi = count;
while (fi > 0) {
fi = fi - 1;
String fldCls = this.allFieldClasses.get(start + fi) as String;
Integer fldClsIdx = this.classIdxOf(fldCls);
if (fldClsIdx >= 0) {
// Load field value
IRValue fldVal = this.emitFieldLoad(objParam, (fi + 1) * 8);

// Null guard for field
String fldSkipLbl = this.newLabel("td_fld_skip");
this.emit(IRInstr.cmp(fldVal, IRValue.ofInt(0, IRType.I64)));
this.emit(IRInstr.branch(IROpcode.JE, fldSkipLbl));

// Decrement field refcount
IRValue fldRC = this.emitFieldLoad(fldVal, this.refCountOff(fldClsIdx));
String nr = this.newReg();
IRValue newRC = IRValue.reg(nr, IRType.I64);
this.emit(IRInstr.binop(IROpcode.SUB, newRC, fldRC, IRValue.ofInt(1, IRType.I64)));
this.emitFieldStore(fldVal, this.refCountOff(fldClsIdx), newRC);

// Conditional free: only when field refcount reaches 0
this.emit(IRInstr.cmp(newRC, IRValue.ofInt(0, IRType.I64)));
String freeSkipLbl = this.newLabel("td_free_skip");
this.emit(IRInstr.branch(IROpcode.JNE, freeSkipLbl));

// CALL child teardown (may be same class → recursive, safe via rc guard)
String childTd = this.teardownLabels.get(fldClsIdx) as String;
if (childTd != "") {
List<IRValue> args = List();
args.append(fldVal);
String dr = this.newReg();
this.emit(IRInstr.call(IRValue.reg(dr, IRType.I64), childTd, args));
}

// Heap free child
this.emitHeapFree(fldVal, fldClsIdx);
this.emit(IRInstr.label(freeSkipLbl));
this.emit(IRInstr.label(fldSkipLbl));
}
}
currIdx = this.classParents.get(currIdx) as Integer;
}

this.emit(IRInstr.retVoid());
}

private generateTeardownRoutines() {
Integer i = 0;
while (i < this.classNames.length()) {
if (this.needsTeardown(i)) {
String label = "__arimo_td_${i}";
this.teardownLabels.set(i, label);
this.beginFn(label, IRType.VOID);
this.addParamToLast("obj", IRType.PTR);
this.emitTeardownBody(i);
}
i = i + 1;
}
}

// ===== ARC release helper =====

private emitRelease(objVal: IRValue, clsIdx: Integer, emitDepth: Integer) {
private emitRelease(objVal: IRValue, clsIdx: Integer) {
// Null guard: release(null) is no-op (prevents SIGSEGV on x=null → scope exit)
String nullSkipLbl = this.newLabel("rel_null_skip");
this.emit(IRInstr.cmp(objVal, IRValue.ofInt(0, IRType.I64)));
Expand All @@ -594,26 +684,14 @@ public class IRLower {
String freeSkipLbl = this.newLabel("rel_free_skip");
this.emit(IRInstr.branch(IROpcode.JNE, freeSkipLbl));

// Recursive field release — walk inheritance chain, release ref-type fields.
// Guard: depth limit prevents stack overflow from deeply nested or
// self-referential types (Expr.left:Expr, Stmt.expr:Expr etc.).
if (emitDepth < 12) {
Integer currIdx = clsIdx;
while (currIdx >= 0) {
Integer start = this.classFldStarts.get(currIdx) as Integer;
Integer count = this.classFldCounts.get(currIdx) as Integer;
Integer fi = count;
while (fi > 0) {
fi = fi - 1;
String fldCls = this.allFieldClasses.get(start + fi) as String;
Integer fldClsIdx = this.classIdxOf(fldCls);
if (fldClsIdx >= 0) {
IRValue fldVal = this.emitFieldLoad(objVal, (fi + 1) * 8);
this.emitRelease(fldVal, fldClsIdx, emitDepth + 1);
}
}
currIdx = this.classParents.get(currIdx) as Integer;
}
// Cached teardown routine: field teardown generated once per class,
// called via runtime CALL (replaces exponential inline expansion).
String tdLabel = this.teardownLabels.get(clsIdx) as String;
if (tdLabel != "") {
List<IRValue> tdArgs = List();
tdArgs.append(objVal);
String tdReg = this.newReg();
this.emit(IRInstr.call(IRValue.reg(tdReg, IRType.I64), tdLabel, tdArgs));
}

this.emitHeapFree(objVal, clsIdx);
Expand Down Expand Up @@ -1054,7 +1132,7 @@ public class IRLower {
String oldCls = this.varClassOf(expr.left.strVal);
Integer oldClsIdx = this.classIdxOf(oldCls);
if (oldClsIdx >= 0) {
this.emitRelease(IRValue.reg(vReg, IRType.I64), oldClsIdx, 0);
this.emitRelease(IRValue.reg(vReg, IRType.I64), oldClsIdx);
}
IRValue dst = IRValue.reg(vReg, IRType.I64);
this.emit(IRInstr.mov(dst, rv));
Expand Down Expand Up @@ -1085,7 +1163,7 @@ public class IRLower {
Integer oldFldClsIdx = this.classIdxOf(oldFldCls);
if (oldFldClsIdx >= 0) {
IRValue oldVal = this.emitFieldLoad(objVal, fldOff);
this.emitRelease(oldVal, oldFldClsIdx, 0);
this.emitRelease(oldVal, oldFldClsIdx);
}
}
this.emitFieldStore(objVal, fldOff, rv2);
Expand Down Expand Up @@ -1228,8 +1306,18 @@ public class IRLower {
}
return IRValue.none();
}
// TODO: Env.args() and Env.exePath() need start function argc/argv setup

if (class_ == "Env" && method == "args") {
// Stub: return empty List<String>. Full argc/argv startup ABI → V1.1.
List<IRValue> la = List();
String lr = this.newReg();
this.emit(IRInstr.call(IRValue.reg(lr, IRType.PTR), "__arimo_list_new", la));
return IRValue.reg(lr, IRType.PTR);
}
if (class_ == "Env" && method == "exePath") {
// Stub: return empty string. Full exePath → V1.1.
return IRValue.global(this.internStr(""));
}
// Generic static call fallback
String fnName = "${class_}__${method}";
List<IRValue> callArgsFn = List();
Integer ai = 0;
Expand Down Expand Up @@ -2710,6 +2798,7 @@ public class IRLower {

public lower(modules: List<ArimoModule>) {
this.registerClasses(modules);
this.generateTeardownRoutines();
this.internStr("\n");
Integer i = 0;
while (i < modules.length()) {
Expand Down
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