A stack is a data structure in which last item inserted is taken out first . That's why they are known as LIFO (last in first out). Inserting an item in stack is termed as push and taking an item out from stack I s termed as pop. Stack pointer is the pointer that points to the top of the stack or that points the item at the top of the stack and help in adding or deleting the item from the top of stack.
top pointer of a stack is the pointer that refers to the top most element of the stack.
The stack register points to the top of the stack for the currently executing thread. The stack is a fixed-length memory allocation at the bottom of addressable memory (highest available address). The stack extends upwards into lower addresses. To keep track of the stack's usage, the stack pointer marks the top of the stack where a new frame will be pushed, decrementing the stack pointer by the required amount. When a frame is popped, the stack pointer is incremented by the frame length. The stack is typically used to call and return from functions by storing the return address of the caller, but can also be used to store a function's arguments (the values passed to it by its caller), its local variables and its exception handlers. Since the memory is allocated as soon as the thread becomes active, moving a pointer to activate and release stack frames is much quicker than requesting heap memory via the operating system.
Because the stack pointer marks the top of the stack. If it is not initialised, it is not possible to determine where the next stack frame will go.
A stack is a data structure in which last item inserted is taken out first . That's why they are known as LIFO (last in first out). Inserting an item in stack is termed as push and taking an item out from stack I s termed as pop. Stack pointer is the pointer that points to the top of the stack or that points the item at the top of the stack and help in adding or deleting the item from the top of stack.
If your stack grows bottom-up, it's decremented when you leave a function; if the stack grows top-down, the stack pointer is incremented.
Actually, stack data starts one location greater than the stack pointer. In the Intel design, the stack pointer always points to the next location to be used on a push, and pushes always decrement the pointer. It is more correct to say that the stack region to be used next is one location less than the stack pointer's register address.
A stack is a data structure in which last item inserted is taken out first . That's why they are known as LIFO (last in first out). Inserting an item in stack is termed as push and taking an item out from stack I s termed as pop. Stack pointer is the pointer that points to the top of the stack or that points the item at the top of the stack and help in adding or deleting the item from the top of stack.
Stack pointer points to the topmost / most recently referenced location on the stack; - Nutan
The top of stack to copied to the specified register and the stack pointer is incremented by 2. A special form of POP, RET, has the program continuing with the popped address in the program counter, i.e. a return from subroutine or function call.
top pointer of a stack is the pointer that refers to the top most element of the stack.
The stack register points to the top of the stack for the currently executing thread. The stack is a fixed-length memory allocation at the bottom of addressable memory (highest available address). The stack extends upwards into lower addresses. To keep track of the stack's usage, the stack pointer marks the top of the stack where a new frame will be pushed, decrementing the stack pointer by the required amount. When a frame is popped, the stack pointer is incremented by the frame length. The stack is typically used to call and return from functions by storing the return address of the caller, but can also be used to store a function's arguments (the values passed to it by its caller), its local variables and its exception handlers. Since the memory is allocated as soon as the thread becomes active, moving a pointer to activate and release stack frames is much quicker than requesting heap memory via the operating system.
The Program Counter and Stack Pointer registers are called special purpose registers because they can not be used arbitrarily; they are, well, special. You cannot, for instance, load a new value into the Program Counter and blithely continue, that action would cause an unconditional jump. Also, the Program Counter is automatically incremented by the size of the instruction, so you can not just put something in it and expect its value to persist. Similarly, you cannot load a new value into the Stack Pointer without losing the entire stack context that you are in.
Accessing a stack.
Its not a stack counter - its a stack pointer. The stack pointer is a register that points to the top of the stack. In the Intel configuration, it points to the next item to be popped off the stack. To push an item requires that the stack pointer be decremented first, and then the item is written. The inverse operation - the pop - requires read then increment.
Because the stack pointer marks the top of the stack. If it is not initialised, it is not possible to determine where the next stack frame will go.
A stack is a data structure in which last item inserted is taken out first . That's why they are known as LIFO (last in first out). Inserting an item in stack is termed as push and taking an item out from stack I s termed as pop. Stack pointer is the pointer that points to the top of the stack or that points the item at the top of the stack and help in adding or deleting the item from the top of stack.