An embodiment of the invention relates to a process for compression of executable code by a microprocessor, comprising decomposing the executable code into words; dividing the executable code into instruction lines; compressing each word of each line in the form of a compressed word of variable length, the compressed words of a line being combined into a line of compressed words; and constituting an addressing table localizing each of the lines of compressed words in a block of lines compressed words and comprising one input per group of lines of compressed words, each input (j) specifying the position of a first line of compressed words in the block, and the respective lengths of the lines of compressed words of group, except for a last line of compressed words of the group, whereof the length is determined by means of the position of a first line of compressed words of a following group.