Art of Assembly Language, 1st Edition

12.2. 12.2 The 80×86 String Instructions

All members of the 80×86 family support five different string instructions: MOVSx, CMPSx, SCASx, LODSx, and STOSx.^[156] (x= B, W, or D for byte, word, or double word, respectively. This text will generally drop the x suffix when talking about these string instructions in a general sense.) They are the string primitives on which you can build most other string operations. How you use these five instructions is the topic of the sections that follow.

^[156] The 80×86 processor support two additional string instructions, INS and OUTS, which input strings of data from an input port or output strings of data to an output port. We will not consider these instructions because they are privileged instructions and ...