To compute accurate information efficiently for programs that use pointer variables, a program analysis must account for the fact that a procedure may access different sets of memory locations when the procedure is invoked under different callsites. This paper presents {\em light-weight context recovery}, a technique that can efficiently determine whether a memory location is accessed by a procedure under a specific callsite. The paper also presents a technique that uses this information to improve the precision and efficiency of program analyses. Our empirical studies show that (1) light-weight context recovery can be quite precise in identifying the memory locations accessed by a procedure under a specific callsite and (2) distinguishing memory locations accessed by a procedure under different callsites can significantly improve the precision and the efficiency of program analyses on programs that use pointer variables.