As the last Subroutine called is the first one to be returned ( Last in first out format). So stack data structure is the most efficient way to store the return addresses of the Subroutines.
Is used to stores the return address when a subroutine call is made?
The Stack in an advanced microprocessor is a versatile memory block, which can be used both automatically – say, for saving a return address in a subroutine call – as well as by the programmer, for short-term data storage. Indeed, in many cases multiple Stacks are used.
Which of the following is used to store the return address of the function calls?
As noted above, the primary purpose of a call stack is to store the return addresses. When a subroutine is called, the location (address) of the instruction at which the calling routine can later resume needs to be saved somewhere.
Which register stores return address?
Not all processor architectures put the return address on the stack- often there’s a set of one or more registers designed to hold return addresses. On ARM processors, the BL instruction places the return address in a specific register ( LR , or the ‘link register’) and transfers control to the function.
Which of the following is a location to save return address in a subroutine call?
Explanation: The return address from the subroutine is pointed to by the PC. Explanation: The registers store the return address of the routine and is pointed to by the PC.
What is subroutine call and return?
The CALL instruction interrupts the flow of a program by passing control to an internal or external subroutine. An external subroutine is another program. ... The RETURN instruction returns control from a subroutine back to the calling program and optionally returns a value.
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”).
Why return statement is used in a subroutine call?
In computer programming, a return statement causes execution to leave the current subroutine and resume at the point in the code immediately after the instruction which called the subroutine , known as its return address.
Which instruction is used to call subroutine?
SECTION 3.2: CALL INSTRUCTIONS
Another control transfer instruction is the CALL instruction, which is used to call a subroutine. Subroutines are often used to perform tasks that need to be performed frequently. This makes a program more structured in addition to saving memory space.
What is the purpose of subroutine register?
4.2 Register usage in subroutine calls
A subroutine is a block of code that performs a task based on some arguments and optionally returns a result . By convention, you use registers R0 to R3 to pass arguments to subroutines, and R0 to pass a result back to the callers.
Is RBP the return address?
2 Answers. Note that the last two instructions (pop and ret) pop two items from the stack, the previous/saved value of rbp and the return address. This means that the return address is right above the saved rbp value on the stack , or at rbp + 8.
Where is the return address stored in stack?
The function return address is placed on the stack by the x86 CALL instruction , which stores the current value of the EIP register. Then, the frame pointer that is the previous value of the EBP register is placed on the stack.
What is EBP register?
A frame pointer (the ebp register on intel x86 architectures, rbp on 64-bit architectures) contains the base address of the function’s frame . The code to access local variables within a function is generated in terms of offsets to the frame pointer.
What is a subroutine call?
In computer: Central processing unit. A related instruction is the subroutine call, which transfers execution to a subprogram and then, after the subprogram finishes, returns to the main program where it left off .
How the stack is used for subroutine call and return?
When a subroutine is called, program control is transferred from the main program to the subroutine. When the subroutine finishes executing, control is returned to the main program. The stack provides the means of connecting the subroutines to the main program .
When a subroutine is called then address of the instruction?
When a subroutine is called, the address of the instruction following the CALL instructions stored in /on the stack . The return address associated with a subroutine is stored in either a processor register or in memory called stack. The program counter then fetches the address of the next instruction from the stack.
