官方代码CollisionManager的疑惑

Creator 2.x
#1 
    update: function (dt) {
        if (!this.enabled) {
            return;
        }

        let i, l;

        // update collider
        let colliders = this._colliders;
        for (i = 0, l = colliders.length; i < l; i++) {
            this.updateCollider(colliders[i]);
        }

        // do collide
        let contacts = this._contacts;
        let results = [];
        
        for (i = 0, l = contacts.length; i < l; i++) {
            let collisionType = contacts[i].updateState();
            if (collisionType === CollisionType.None) {
                continue;
            }

            results.push([collisionType, contacts[i]]);
        }

        // handle collide results, emit message
        for (i = 0, l = results.length; i < l; i++) {
            let result = results[i];
            this._doCollide(result[0], result[1]);
        }

        // draw colliders
        this.drawColliders();
    },

每帧都let results = [];真的不考虑效率么？