Patent ID: 9098319
Filing Date: 2015-08-04
Classification: G06F

Abstract:
1. A computer-implemented code conversion method for reading program code and inserting reference count decrement code (RC−) to decrement a reference count into code having two or more successor basic blocks to a first basic block, the method comprising the step of: responding to a variable, the variable identical to a variable that is live at the entry of a second basic block among the successor basic blocks and that is not live in a third basic block separate from the second basic block among the successor basic blocks, by inserting a new fourth basic block between the first basic block and the third basic block, and by inserting RC− related to the variable in the new fourth basic block; wherein RC− is not inserted in a successor basic block in the case of a variable having a lifetime within a proceeding basic block; and wherein after a given RC− insertion: (a) an address of an object does not need to be rendered NULL after the last use of the object; and (b) a check is not required to determine whether or not the address of the object has been rendered NULL at the given RC− insertion.