| 摘要 |
A compiler is provided for compiling program instructions in dependence upon a predetermined decoder input instruction alignment. The compiler comprises a program instruction sequence generator operable to process source code to produce a sequence comprising a plurality of program instructions for input to a decoder. At least one program instruction is reordered within a storage region of program memory. The storage region has an associated memory address and an offset value. The offset value gives a starting location of said program instruction within the memory address. The reordering of the program instruction is such that manipulations of instruction units of the plurality of program instructions required to achieve the predetermined decoder input instruction alignment are less complex than manipulations that would be required if no reordering had been performed. According to a further aspect, a program instruction aligner is provided to shift at least one portion of the reordered (reformatted) program instruction to produce the predetermined decoder-input instruction alignment. The offset value and an instruction length are supplied as control inputs to the program instruction aligner. A plurality of connections between register fields and shifter fields of the program instruction aligner is such that at least one of said plurality of register fields is connected to only a subset of said plurality of shifter fields.
|
