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How do I find the value of a stack pointer?
The stack pointer (SP) points to the top element of the stack. The current value of SP is (016E)hex. The CALL instruction is of two words, the first word is the op-code and second word is the starting address of the subroutine (one word = 2 Bytes).
Where is the stack pointer located?
They are the stack pointer, SP, and the program counter, PC. The Stack Pointer register will hold the address of the top location of the stack. And the program counter is a register always it will hold the address of the memory location from where the next instruction for execution will have to be fetched.
What is the position of stack pointer after the push instruction?
In PUSH instruction, after each execution of the instruction, the stack pointer is a) incremented by 1 b) decremented by 1 c) incremented by 2 d) decremented by 2 Answer: d Explanation: The actual current stack-top is always occupied by the previously pushed data.
What is top pointer in stack?
A stack pointer is a small register that stores the address of the last program request in a stack. The most recently entered request always resides at the top of the stack, and the program always takes requests from the top. A stack (also called a pushdown stack) operates in a last-in/first-out sense.
What is stack pointer used for?
The stack pointer is mainly used as a memory pointer which specifies to the memory location that read and write memory to that location. The typical usage of the stack pointer is to hold stack bits that belong to the present function.
How many pointers are used in stack?
Physically there are two stack pointers in the Cortex-M processors, but only one of them is used at a time, depending on the current value of the CONTROL register and the state of the processor (see Figure 4.8).
Can we execute a subroutine without stack?
In practice, many languages do both, but in such a way that it’s indistinguishable from always using the stack, because the stack is needed to handle recursion (and, these days, reentrancy), and executing a subroutine without using the stack is treated purely as an optimisation (often, “inlining”).
How to track the maximum element in a stack?
Tracking current Maximum Element in a Stack. Given a Stack, keep track of the maximum value in it. The maximum value may be the top element of the stack, but once a new element is pushed or an element is pop from the stack, the maximum element will be now from the rest of the elements.
How to push an element to the top of a stack?
Now from the second element, push the element to the main stack. Compare the element with the top element of the track stack, if the current element is greater than the top of trackStack then push the current element to trackStack otherwise push the top element of trackStack again into it.
How to implement the stack : top ( ) function?
Since you already store top, you can just return p [top]. Or in other words: top () would essentially be the same as pop (), it just won’t remove the top element. Thanks for contributing an answer to Stack Overflow! Please be sure to answer the question.
When is the maximum element in a stack still maxele?
Two cases arise: If y is less than or equal to maxEle, the maximum element in the stack is still maxEle. If y is greater than maxEle, the maximum element now becomes (2*maxEle – y), so update (maxEle = 2*maxEle – y).