Patent ID: 6115811
Filing Date: 2000-09-05
Classification: G06F

Abstract:
A code generator for generating program code for execution by a digital computer, the program code comprising a sequence of instructions to be executed by said digital computer, the digital computer including (i) a plurality of storage locations, each identified by a storage location identifier, said instructions being stored in respective ones of said storage locations and (ii) an old program counter for storing a prior instruction storage location identifier identifying one of said storage locations containing one of said instructions executed by said digital computer prior to the one of the instructions currently being executed by said digital computer, the code generator comprising:A. an instruction sequence discontinuity detector for determining whether an instruction in said sequence may give rise to a discontinuity in execution of said instruction sequence;B. a ""branch taken"" instruction sequence portion detector responsive to a positive determination by said instruction sequence discontinuity detector for identifying a ""branch taken"" portion of the instruction sequence; andC. a read old program counter instruction inserter for inserting into said ""branch taken"" instruction portion of the instruction sequence a read old program counter instruction thereby to enable said digital computer to copy the prior instruction storage location identifier from the old program counter to the one of said storage locations identified by the instruction of the read old program counter instruction type.