eaglercraft/eagler-teavm-fork
1
0
Fork 0
mirror of https://github.com/Eaglercraft-TeaVM-Fork/eagler-teavm.git synced 2025-01-09 08:24:10 -08:00
Code Issues Actions Packages Projects Releases Wiki Activity

Fix evaluation order when eliminating redundant variables from AST

Browse Source 
See #330
This commit is contained in:
Alexey Andreev 2018-02-17 01:29:26 +03:00
parent 52a23fcadd
commit 788e506175
1 changed files with 127 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

139
core/src/main/java/org/teavm/ast/optimization/OptimizingVisitor.java
View File

@ -122,16 +122,35 @@ class OptimizingVisitor implements StatementVisitor, ExprVisitor {
Expr b = expr.getSecondOperand(); Expr b = expr.getSecondOperand();
Expr a = expr.getFirstOperand(); Expr a = expr.getFirstOperand();
if (a instanceof VariableExpr || a instanceof ConstantExpr) { int barrierPosition = 0;
b.acceptVisitor(this); if (isSideEffectFree(a)) {
b = resultExpr; barrierPosition++;
if (b instanceof ConstantExpr && expr.getOperation() == BinaryOperation.SUBTRACT) { if (isSideEffectFree(b)) {
if (tryMakePositive((ConstantExpr) b)) { barrierPosition++;
expr.setOperation(BinaryOperation.ADD);
}
} }
a.acceptVisitor(this); }
a = resultExpr;
Statement barrier = addBarrier();
if (barrierPosition == 2) {
removeBarrier(barrier);
}
b.acceptVisitor(this);
b = resultExpr;
if (b instanceof ConstantExpr && expr.getOperation() == BinaryOperation.SUBTRACT) {
if (tryMakePositive((ConstantExpr) b)) {
expr.setOperation(BinaryOperation.ADD);
}
}
if (barrierPosition == 1) {
removeBarrier(barrier);
}
a.acceptVisitor(this);
a = resultExpr;
if (barrierPosition == 0) {
removeBarrier(barrier);
} }
Expr p = a; Expr p = a;
@ -223,10 +242,14 @@ class OptimizingVisitor implements StatementVisitor, ExprVisitor {
try { try {
expr.getCondition().acceptVisitor(this); expr.getCondition().acceptVisitor(this);
Expr cond = resultExpr; Expr cond = resultExpr;
Statement barrier = addBarrier();
expr.getConsequent().acceptVisitor(this); expr.getConsequent().acceptVisitor(this);
Expr consequent = resultExpr; Expr consequent = resultExpr;
expr.getAlternative().acceptVisitor(this); expr.getAlternative().acceptVisitor(this);
Expr alternative = resultExpr; Expr alternative = resultExpr;
removeBarrier(barrier);
expr.setCondition(cond); expr.setCondition(cond);
expr.setConsequent(consequent); expr.setConsequent(consequent);
expr.setAlternative(alternative); expr.setAlternative(alternative);
@ -288,10 +311,37 @@ class OptimizingVisitor implements StatementVisitor, ExprVisitor {
public void visit(SubscriptExpr expr) { public void visit(SubscriptExpr expr) {
pushLocation(expr.getLocation()); pushLocation(expr.getLocation());
try { try {
Expr index = expr.getIndex();
Expr array = expr.getArray();
int barrierPosition = 0;
if (isSideEffectFree(array)) {
++barrierPosition;
if (isSideEffectFree(index)) {
++barrierPosition;
}
}
Statement barrier = addBarrier();
if (barrierPosition == 2) {
removeBarrier(barrier);
}
expr.getIndex().acceptVisitor(this); expr.getIndex().acceptVisitor(this);
Expr index = resultExpr; index = resultExpr;
if (barrierPosition == 1) {
removeBarrier(barrier);
}
expr.getArray().acceptVisitor(this); expr.getArray().acceptVisitor(this);
Expr array = resultExpr; array = resultExpr;
if (barrierPosition == 0) {
removeBarrier(barrier);
}
expr.setArray(array); expr.setArray(array);
expr.setIndex(index); expr.setIndex(index);
resultExpr = expr; resultExpr = expr;
@ -318,13 +368,32 @@ class OptimizingVisitor implements StatementVisitor, ExprVisitor {
pushLocation(expr.getLocation()); pushLocation(expr.getLocation());
try { try {
Expr[] args = new Expr[expr.getArguments().size()]; Expr[] args = new Expr[expr.getArguments().size()];
for (int i = expr.getArguments().size() - 1; i >= 0; --i) { int barrierPos;
for (barrierPos = 0; barrierPos < args.length; ++barrierPos) {
if (!isSideEffectFree(args[barrierPos])) {
break;
}
}
Statement barrier = addBarrier();
if (barrierPos == args.length) {
removeBarrier(barrier);
}
for (int i = args.length - 1; i >= 0; --i) {
expr.getArguments().get(i).acceptVisitor(this); expr.getArguments().get(i).acceptVisitor(this);
args[i] = resultExpr; args[i] = resultExpr;
if (i == barrierPos) {
removeBarrier(barrier);
}
} }
for (int i = 0; i < args.length; ++i) { for (int i = 0; i < args.length; ++i) {
expr.getArguments().set(i, args[i]); expr.getArguments().set(i, args[i]);
} }
resultExpr = expr; resultExpr = expr;
} finally { } finally {
popLocation(); popLocation();
@ -901,4 +970,50 @@ class OptimizingVisitor implements StatementVisitor, ExprVisitor {
popLocation(); popLocation();
} }
} }
private Statement addBarrier() {
SequentialStatement barrier = new SequentialStatement();
resultSequence.add(barrier);
return barrier;
}
private void removeBarrier(Statement barrier) {
Statement removedBarrier = resultSequence.remove(resultSequence.size() - 1);
if (removedBarrier != barrier) {
throw new AssertionError();
}
}
private boolean isSideEffectFree(Expr expr) {
if (expr == null) {
return true;
}
if (expr instanceof VariableExpr || expr instanceof ConstantExpr) {
return true;
}
if (expr instanceof BinaryExpr) {
BinaryExpr binary = (BinaryExpr) expr;
return isSideEffectFree(binary.getFirstOperand()) && isSideEffectFree(binary.getSecondOperand());
}
if (expr instanceof UnaryExpr) {
return isSideEffectFree(((UnaryExpr) expr).getOperand());
}
if (expr instanceof InstanceOfExpr) {
return isSideEffectFree(((InstanceOfExpr) expr).getExpr());
}
if (expr instanceof PrimitiveCastExpr) {
return isSideEffectFree(((PrimitiveCastExpr) expr).getValue());
}
if (expr instanceof NewExpr) {
return true;
}
return false;
}
} }