The phrase "didst u turn" is an archaic way of saying "you turned." Synonyms for this phrase would include "you rotated," "you pivoted," or simply "you changed direction." Other possible synonyms could include "you swiveled," "you veered," or "you reversed course." Depending on the context in which the phrase is used, other synonyms might be more appropriate, such as "you redirected," "you circled around," or "you went back the way you came." Ultimately, the choice of synonym will depend on the intended meaning of the phrase and the tone of the surrounding text.