Function matchEquNequZero

src/ast/ast_match.cpp:9–24

recognize a==0, a!=0, 0==a, 0!=a

    // recognize a==0, a!=0, 0==a, 0!=a
    bool matchEquNequZero ( ExpressionPtr expr, ExpressionPtr & zeroCond, bool & condIfZero ) {
        if ( expr->rtti_isOp2() ) {
            auto op2 = static_cast<ExprOp2*>(expr);
            if ( op2->op=="==" || op2->op=="!=" ) {
                condIfZero = op2->op == "==";
                if ( isZeroConst(op2->left) ) {
                    zeroCond = op2->right;
                    return true;
                } else if ( isZeroConst(op2->right) ) {
                    zeroCond = op2->left;
                    return true;
                }
            }
        }
        return false;
    }

    bool isZeroConst ( ExpressionPtr expr ) {
        return isFloatConst(expr, 0.0f) || isIntOrUIntConst(expr, 0) || isPtrZero(expr);