4.1 The Y86-64 Instruction Set Architecture

4.1.1 Programmer-Visible State

• As Figure 4.1 illustrates, each instruction in a Y86-64 program can read and modify some part of the processor state.
• Register %rsp is used as a stack pointer by the push, pop, call, and return instructions

• There are three single-bit condition codes, ZF, SF, and OF, storing information about the effect of the most recent arithmetic or logical instruction. The program counter (PC) holds the address of the instruction currently being executed.

• The memory is conceptually a large array of bytes, holding both program and data.
• A final part of the program state is a status code Stat, indicating the overall state of program execution. It will indicate either normal operation or that some sort of exception has occurred

 

4.1.2 Y86-64 Instructions

 

4.1.3 Instruction Encoding

 

4.1.4 Y86-64 Exceptions