Freaks City

x86-64 Register Set and Usage The x86-64 architecture includes 16 general-purpose registers that store 64-bit values. While these register are general-purpose, they follow conventional usage patterns. The registers r8 through r15 were added in the 80386 architecture extension. %rax: Return value register %rbx: Callee-saved register %rcx: 4th f ...

Function Call Mechanism A fundamental question that often arises: When function A calls function B, how does B know where to return after completion? Consider the following code snippet where main invokes compute. Once compute finishes execution, control must flow back to main's return statement. But these two functions are separate entities—ho ...