Combining results of selectively executed remaining sub-instructions with that of emulated sub-instruction causing exception in VLIW processor

摘要

One embodiment of the present invention provides a system that efficiently emulates sub-instructions in a very long instruction word (VLIW) processor. The system operates by receiving an exception condition during execution of a VLIW instruction within a VLIW program. This exception condition indicates that at least one sub-instruction within the VLIW instruction requires emulation in software or software assistance. In processing this exception condition, the system emulates the sub-instructions that require emulation in software and stores the results. The system also selectively executes in hardware any remaining sub-instructions in the VLIW instruction that do not require emulation in software. The system finally combines the results from the sub-instructions emulated in software with the results from the remaining sub-instructions executed in hardware, and resumes execution of the VLIW program.