Instructions-I
Explore the ARM64 instruction set focusing on PSTATE flags and conditional jumps. Understand how flags like N, Z, C, and V affect CPU execution and how conditional branch instructions control program flow. Learn how function return values use registers and how the Z flag is set through arithmetic and compare instructions.
We'll cover the following...
The PSTATE flags
In addition to registers, the CPU also contains a 32-bit PSTATE where four individual bits N, Z, C, and V are set or cleared in response to arithmetic and other operations. Separate machine instructions can manipulate some bit values, and their values affect code execution. These flags have their own special register, NZCV.
The illustration below shows the four individual bits:
Conditional jumps
Consider these two C/C++ code fragments. The first code for the ...