A computer system and method for compressing an instruction stream and executing
the compressed instruction stream without decompression. The invention utilizes
a new pointer instruction, i.e., an "Echo" instruction that is used to replace
repeated instructions or sequences of instructions, also referred to as phrases.
Replacing subsequent, repeated phrases with the Echo instruction reduces the size
of the instruction stream, i.e., compresses the instruction stream. The Echo instruction
generally identifies at least one literal instruction appearing before the Echo
instruction and further identifies the number of instructions appearing before
the Echo instruction to be repeated. No additional delimiters are necessary, e.g.,
no End Echo instructions are required. Omitting the End Echo instruction allows
for overlapping phrases without the need for two Echo instructions. Reducing the
number of instructions used significantly increases compression.
