[Tutor] following on

[Dave Angel]

On 02/18/2013 02:01 PM, Matthew Ngaha wrote:
>>>    <snip>
>>
> i sort of heard about a stack its a C/C++ thing i think?
>

A stack is fundamental to modern programming languages.  The only two 
machines I've used that didn't have a stack implemented at the machine 
level were the CDC 6000 series, and the IBM 360.  Both products of the 60's.

Processors like the Intel Pentium series have a stack microcoded into 
their lowest level instruction set.  When the processor itself is 
calling a subroutine, the current address is pushed onto the stack, and 
the return instruction pops it back off and jumps there.  Other 
instructions for manipulating it exist at the same level.  Typically all 
local variables in a function are stored in the current stack frame. 
The stack makes recursive functions practical, at a minimum.  Having 
multiple stacks makes multithreading practical as well.

Recursion and multithreading was very tricky on the CDC, since it stored 
return addresses right into the running code.

Usually a programming language will provide a stack-like data structure, 
for manipulating data that needs similar behavior.


-- 
DaveA