/** Code generation for a binary operation */ public void generateCode(BlockScope currentScope, CodeStream codeStream, boolean valueRequired) { int pc = codeStream.position; if (this.constant != Constant.NotAConstant) { // inlined value if (valueRequired) codeStream.generateConstant(this.constant, this.implicitConversion); codeStream.recordPositionsFrom(pc, this.sourceStart); return; } Constant cst = this.right.constant; if (cst != Constant.NotAConstant) { // <expr> || true --> true if (cst.booleanValue() == true) { this.left.generateCode(currentScope, codeStream, false); if (valueRequired) codeStream.iconst_1(); } else { // <expr>|| false --> <expr> this.left.generateCode(currentScope, codeStream, valueRequired); } if (this.mergedInitStateIndex != -1) { codeStream.removeNotDefinitelyAssignedVariables(currentScope, this.mergedInitStateIndex); } codeStream.generateImplicitConversion(this.implicitConversion); codeStream.recordPositionsFrom(pc, this.sourceStart); return; } BranchLabel trueLabel = new BranchLabel(codeStream), endLabel; cst = this.left.optimizedBooleanConstant(); boolean leftIsConst = cst != Constant.NotAConstant; boolean leftIsTrue = leftIsConst && cst.booleanValue() == true; cst = this.right.optimizedBooleanConstant(); boolean rightIsConst = cst != Constant.NotAConstant; boolean rightIsTrue = rightIsConst && cst.booleanValue() == true; generateOperands: { if (leftIsConst) { this.left.generateCode(currentScope, codeStream, false); if (leftIsTrue) { break generateOperands; // no need to generate right operand } } else { this.left.generateOptimizedBoolean(currentScope, codeStream, trueLabel, null, true); // need value, e.g. if (a == 1 || ((b = 2) > 0)) {} -> shouldn't initialize 'b' if a==1 } if (this.rightInitStateIndex != -1) { codeStream.addDefinitelyAssignedVariables(currentScope, this.rightInitStateIndex); } if (rightIsConst) { this.right.generateCode(currentScope, codeStream, false); } else { this.right.generateOptimizedBoolean( currentScope, codeStream, trueLabel, null, valueRequired); } } if (this.mergedInitStateIndex != -1) { codeStream.removeNotDefinitelyAssignedVariables(currentScope, this.mergedInitStateIndex); } /* * improving code gen for such a case: boolean b = i < 0 || true since * the label has never been used, we have the inlined value on the * stack. */ if (valueRequired) { if (leftIsConst && leftIsTrue) { codeStream.iconst_1(); codeStream.recordPositionsFrom(codeStream.position, this.left.sourceEnd); } else { if (rightIsConst && rightIsTrue) { codeStream.iconst_1(); codeStream.recordPositionsFrom(codeStream.position, this.left.sourceEnd); } else { codeStream.iconst_0(); } if (trueLabel.forwardReferenceCount() > 0) { if ((this.bits & IsReturnedValue) != 0) { codeStream.generateImplicitConversion(this.implicitConversion); codeStream.generateReturnBytecode(this); trueLabel.place(); codeStream.iconst_1(); } else { codeStream.goto_(endLabel = new BranchLabel(codeStream)); codeStream.decrStackSize(1); trueLabel.place(); codeStream.iconst_1(); endLabel.place(); } } else { trueLabel.place(); } } codeStream.generateImplicitConversion(this.implicitConversion); codeStream.recordPositionsFrom(codeStream.position, this.sourceEnd); } else { trueLabel.place(); } }