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Merged
merged 7 commits into from
Feb 18, 2025
Merged

Initial null support in optimizing compiler - missing null checks #30

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2c2cabc
Improved type checking - also some fixes to test cases that broke aft…
dibyendumajumdar Feb 16, 2025
985cf88
Initial work on implementing Null support in registervm - as well as …
dibyendumajumdar Feb 16, 2025
7e3632b
Ensure SSA tests check output
dibyendumajumdar Feb 18, 2025
cfd9b76
Fix bug in EnterSSA caused by mutable operands shared across instruct…
dibyendumajumdar Feb 18, 2025
0c82836
more work on boolean binary expressions
dibyendumajumdar Feb 17, 2025
f666feb
Initial support for nulls in optvm - but we are missing null check at…
dibyendumajumdar Feb 18, 2025
ebfbdde
Merge branch 'main' into develop
dibyendumajumdar Feb 18, 2025
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32 changes: 23 additions & 9 deletions optvm/src/main/java/com/compilerprogramming/ezlang/compiler/CompiledFunction.java
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Original file line number Diff line number Diff line change
Expand Up @@ -460,13 +460,10 @@ private boolean codeBoolean(AST.BinaryExpr binaryExpr) {
jumpTo(l3);
startBlock(l2);
// Below we must write to the same temp
//code(new Instruction.Move(new Operand.ConstantOperand(isAnd ? 0 : 1, typeDictionary.INT), new Operand.TempRegisterOperand(temp.reg)));
code(new Instruction.Move(new Operand.ConstantOperand(isAnd ? 0 : 1, typeDictionary.INT), temp));
jumpTo(l3);
startBlock(l3);
// leave temp on virtual stack
// var temp2 = (Operand.TempRegisterOperand) pop();
// pushOperand(new Operand.TempRegisterOperand(temp2.reg));
return false;
}

Expand All @@ -483,10 +480,19 @@ private boolean compileBinaryExpr(AST.BinaryExpr binaryExpr) {
indexed = compileExpr(binaryExpr.expr2);
if (indexed)
codeIndexedLoad();
opCode = binaryExpr.op.str;
Operand right = pop();
Operand left = pop();
if (left instanceof Operand.ConstantOperand leftconstant &&
if (left instanceof Operand.NullConstantOperand &&
right instanceof Operand.NullConstantOperand) {
long value = 0;
switch (opCode) {
case "==": value = 1; break;
case "!=": value = 0; break;
default: throw new CompilerException("Invalid binary op");
}
pushConstant(value, typeDictionary.INT);
}
else if (left instanceof Operand.ConstantOperand leftconstant &&
right instanceof Operand.ConstantOperand rightconstant) {
long value = 0;
switch (opCode) {
Expand Down Expand Up @@ -535,14 +541,22 @@ private boolean compileUnaryExpr(AST.UnaryExpr unaryExpr) {
}

private boolean compileConstantExpr(AST.LiteralExpr constantExpr) {
pushConstant(constantExpr.value.num.intValue(), constantExpr.type);
if (constantExpr.type instanceof Type.TypeInteger)
pushConstant(constantExpr.value.num.intValue(), constantExpr.type);
else if (constantExpr.type instanceof Type.TypeNull)
pushNullConstant(constantExpr.type);
else throw new CompilerException("Invalid constant type");
return false;
}

private void pushConstant(long value, Type type) {
pushOperand(new Operand.ConstantOperand(value, type));
}

private void pushNullConstant(Type type) {
pushOperand(new Operand.NullConstantOperand(type));
}

private Operand.TempRegisterOperand createTemp(Type type) {
var tempRegister = new Operand.TempRegisterOperand(registerPool.newTempReg(type));
pushOperand(tempRegister);
Expand All @@ -552,8 +566,8 @@ private Operand.TempRegisterOperand createTemp(Type type) {
Type typeOfOperand(Operand operand) {
if (operand instanceof Operand.ConstantOperand constant)
return constant.type;
// else if (operand instanceof Operand.NullConstantOperand nullConstantOperand)
// return nullConstantOperand.type;
else if (operand instanceof Operand.NullConstantOperand nullConstantOperand)
return nullConstantOperand.type;
else if (operand instanceof Operand.RegisterOperand registerOperand)
return registerOperand.type;
else throw new CompilerException("Invalid operand");
Expand All @@ -569,7 +583,7 @@ private Operand.TempRegisterOperand createTempAndMove(Operand src) {
private Operand.RegisterOperand ensureTemp() {
Operand top = top();
if (top instanceof Operand.ConstantOperand
//|| top instanceof Operand.NullConstantOperand
|| top instanceof Operand.NullConstantOperand
|| top instanceof Operand.LocalRegisterOperand) {
return createTempAndMove(pop());
} else if (top instanceof Operand.IndexedOperand) {
Expand Down
2 changes: 1 addition & 1 deletion optvm/src/main/java/com/compilerprogramming/ezlang/compiler/InterferenceGraph.java
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Original file line number Diff line number Diff line change
Expand Up @@ -65,7 +65,7 @@ public void rename(Integer source, Integer target) {
var toSet = edges.get(target);
if (toSet == null) {
//throw new RuntimeException("Cannot find edge " + target + " from " + source);
return; // FIXME this is workaround to handle sceanrio where target is arg register but we need a better way
return; // FIXME this is workaround to handle scenario where target is arg register but we need a better way
}
toSet.addAll(fromSet);
// If any node interfered with from
Expand Down
10 changes: 10 additions & 0 deletions optvm/src/main/java/com/compilerprogramming/ezlang/compiler/Operand.java
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Expand Up @@ -18,6 +18,16 @@ public String toString() {
}
}

public static class NullConstantOperand extends Operand {
public NullConstantOperand(Type type) {
this.type = type;
}
@Override
public String toString() {
return "null";
}
}

public static class RegisterOperand extends Operand {
final Register reg;
protected RegisterOperand(Register reg) {
Expand Down
47 changes: 26 additions & 21 deletions ...in/java/com/compilerprogramming/ezlang/compiler/SparseConditionalConstantPropagation.java
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Expand Up @@ -377,35 +377,40 @@ private boolean evalInstruction(Instruction instruction) {
}
case Instruction.Binary binaryInst -> {
var cell = valueLattice.get(binaryInst.result().reg);
LatticeElement left, right;
LatticeElement left = null;
LatticeElement right = null;
// TODO we cannot yet evaluate null in comparisons
if (binaryInst.left() instanceof Operand.ConstantOperand constant)
left = new LatticeElement(V_CONSTANT, constant.value);
else if (binaryInst.left() instanceof Operand.RegisterOperand registerOperand)
left = valueLattice.get(registerOperand.reg);
else throw new IllegalStateException();
if (binaryInst.right() instanceof Operand.ConstantOperand constant)
right = new LatticeElement(V_CONSTANT, constant.value);
else if (binaryInst.right() instanceof Operand.RegisterOperand registerOperand)
right = valueLattice.get(registerOperand.reg);
else throw new IllegalStateException();
switch (binaryInst.binOp) {
case "+":
case "-":
case "*":
case "/":
case "%":
changed = evalArith(cell, left, right, binaryInst.binOp);
break;
case "==":
case "!=":
case "<":
case ">":
case "<=":
case ">=":
changed = evalLogical(cell, left, right, binaryInst.binOp);
break;
default:
throw new IllegalStateException();
if (left != null && right != null) {
switch (binaryInst.binOp) {
case "+":
case "-":
case "*":
case "/":
case "%":
changed = evalArith(cell, left, right, binaryInst.binOp);
break;
case "==":
case "!=":
case "<":
case ">":
case "<=":
case ">=":
changed = evalLogical(cell, left, right, binaryInst.binOp);
break;
default:
throw new IllegalStateException();
}
}
else {
cell.setKind(V_VARYING);
}
}
case Instruction.NewArray newArrayInst -> {
Expand Down
95 changes: 71 additions & 24 deletions optvm/src/main/java/com/compilerprogramming/ezlang/interpreter/Interpreter.java
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Expand Up @@ -48,6 +48,9 @@ public Value interpret(ExecutionStack execStack, Frame frame) {
if (retInst.value() instanceof Operand.ConstantOperand constantOperand) {
execStack.stack[base] = new Value.IntegerValue(constantOperand.value);
}
else if (retInst.value() instanceof Operand.NullConstantOperand) {
execStack.stack[base] = new Value.NullValue();
}
else if (retInst.value() instanceof Operand.RegisterOperand registerOperand) {
execStack.stack[base] = execStack.stack[base+registerOperand.frameSlot()];
}
Expand All @@ -63,6 +66,9 @@ else if (retInst.value() instanceof Operand.RegisterOperand registerOperand) {
else if (moveInst.from() instanceof Operand.ConstantOperand constantOperand) {
execStack.stack[base + toReg.frameSlot()] = new Value.IntegerValue(constantOperand.value);
}
else if (moveInst.from() instanceof Operand.NullConstantOperand) {
execStack.stack[base + toReg.frameSlot()] = new Value.NullValue();
}
else throw new IllegalStateException();
}
else throw new IllegalStateException();
Expand Down Expand Up @@ -107,6 +113,9 @@ else if (cbrInst.condition() instanceof Operand.ConstantOperand constantOperand)
else if (arg instanceof Operand.ConstantOperand constantOperand) {
execStack.stack[base + reg] = new Value.IntegerValue(constantOperand.value);
}
else if (arg instanceof Operand.NullConstantOperand) {
execStack.stack[base + reg] = new Value.NullValue();
}
reg += 1;
}
// Call function
Expand Down Expand Up @@ -135,31 +144,60 @@ else if (arg instanceof Operand.ConstantOperand constantOperand) {
case Instruction.Binary binaryInst -> {
long x, y;
long value = 0;
if (binaryInst.left() instanceof Operand.ConstantOperand constant)
x = constant.value;
else if (binaryInst.left() instanceof Operand.RegisterOperand registerOperand)
x = ((Value.IntegerValue) execStack.stack[base + registerOperand.frameSlot()]).value;
else throw new IllegalStateException();
if (binaryInst.right() instanceof Operand.ConstantOperand constant)
y = constant.value;
else if (binaryInst.right() instanceof Operand.RegisterOperand registerOperand)
y = ((Value.IntegerValue) execStack.stack[base + registerOperand.frameSlot()]).value;
else throw new IllegalStateException();
switch (binaryInst.binOp) {
case "+": value = x + y; break;
case "-": value = x - y; break;
case "*": value = x * y; break;
case "/": value = x / y; break;
case "%": value = x % y; break;
case "==": value = x == y ? 1 : 0; break;
case "!=": value = x != y ? 1 : 0; break;
case "<": value = x < y ? 1: 0; break;
case ">": value = x > y ? 1 : 0; break;
case "<=": value = x <= y ? 1 : 0; break;
case ">=": value = x <= y ? 1 : 0; break;
default: throw new IllegalStateException();
boolean intOp = true;
if (binaryInst.binOp.equals("==") || binaryInst.binOp.equals("!=")) {
Operand.RegisterOperand nonNullLitOperand = null;
if (binaryInst.left() instanceof Operand.NullConstantOperand) {
nonNullLitOperand = (Operand.RegisterOperand)binaryInst.right();
}
else if (binaryInst.right() instanceof Operand.NullConstantOperand) {
nonNullLitOperand = (Operand.RegisterOperand)binaryInst.left();
}
if (nonNullLitOperand != null) {
intOp = false;
Value otherValue = execStack.stack[base + nonNullLitOperand.frameSlot()];
switch (binaryInst.binOp) {
case "==": {
value = otherValue instanceof Value.NullValue ? 1 : 0;
break;
}
case "!=": {
value = otherValue instanceof Value.NullValue ? 0 : 1;
break;
}
default:
throw new IllegalStateException();
}
execStack.stack[base + binaryInst.result().frameSlot()] = new Value.IntegerValue(value);
}
}
if (intOp) {
if (binaryInst.left() instanceof Operand.ConstantOperand constant)
x = constant.value;
else if (binaryInst.left() instanceof Operand.RegisterOperand registerOperand)
x = ((Value.IntegerValue) execStack.stack[base + registerOperand.frameSlot()]).value;
else throw new IllegalStateException();
if (binaryInst.right() instanceof Operand.ConstantOperand constant)
y = constant.value;
else if (binaryInst.right() instanceof Operand.RegisterOperand registerOperand)
y = ((Value.IntegerValue) execStack.stack[base + registerOperand.frameSlot()]).value;
else throw new IllegalStateException();
switch (binaryInst.binOp) {
case "+": value = x + y; break;
case "-": value = x - y; break;
case "*": value = x * y; break;
case "/": value = x / y; break;
case "%": value = x % y; break;
case "==": value = x == y ? 1 : 0; break;
case "!=": value = x != y ? 1 : 0; break;
case "<": value = x < y ? 1: 0; break;
case ">": value = x > y ? 1 : 0; break;
case "<=": value = x <= y ? 1 : 0; break;
case ">=": value = x <= y ? 1 : 0; break;
default: throw new IllegalStateException();
}
execStack.stack[base + binaryInst.result().frameSlot()] = new Value.IntegerValue(value);
}
execStack.stack[base + binaryInst.result().frameSlot()] = new Value.IntegerValue(value);
}
case Instruction.NewArray newArrayInst -> {
execStack.stack[base + newArrayInst.destOperand().frameSlot()] = new Value.ArrayValue(newArrayInst.type);
Expand All @@ -172,6 +210,9 @@ else if (binaryInst.right() instanceof Operand.RegisterOperand registerOperand)
if (arrayAppendInst.value() instanceof Operand.ConstantOperand constant) {
arrayValue.values.add(new Value.IntegerValue(constant.value));
}
else if (arrayAppendInst.value() instanceof Operand.NullConstantOperand) {
arrayValue.values.add(new Value.NullValue());
}
else if (arrayAppendInst.value() instanceof Operand.RegisterOperand registerOperand) {
arrayValue.values.add(execStack.stack[base + registerOperand.frameSlot()]);
}
Expand All @@ -193,6 +234,9 @@ else if (arrayStoreInst.indexOperand() instanceof Operand.RegisterOperand regist
if (arrayStoreInst.sourceOperand() instanceof Operand.ConstantOperand constantOperand) {
value = new Value.IntegerValue(constantOperand.value);
}
else if (arrayStoreInst.sourceOperand() instanceof Operand.NullConstantOperand) {
value = new Value.NullValue();
}
else if (arrayStoreInst.sourceOperand() instanceof Operand.RegisterOperand registerOperand) {
value = execStack.stack[base + registerOperand.frameSlot()];
}
Expand Down Expand Up @@ -221,6 +265,9 @@ else if (arrayLoadInst.indexOperand() instanceof Operand.RegisterOperand registe
if (setFieldInst.sourceOperand() instanceof Operand.ConstantOperand constant) {
value = new Value.IntegerValue(constant.value);
}
else if (setFieldInst.sourceOperand() instanceof Operand.NullConstantOperand) {
value = new Value.NullValue();
}
else if (setFieldInst.sourceOperand() instanceof Operand.RegisterOperand registerOperand) {
value = execStack.stack[base + registerOperand.frameSlot()];
}
Expand Down
3 changes: 3 additions & 0 deletions optvm/src/main/java/com/compilerprogramming/ezlang/interpreter/Value.java
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Expand Up @@ -11,6 +11,9 @@ public IntegerValue(long value) {
}
public final long value;
}
static public class NullValue extends Value {
public NullValue() {}
}
static public class ArrayValue extends Value {
public final Type.TypeArray arrayType;
public final ArrayList<Value> values;
Expand Down
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