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For instruction set architectures in which the instruction used to call a subroutine puts the return address into a register, rather than pushing it onto the stack, the prologue will commonly save the return address by pushing the value onto the call stack, although if the called subroutine does not call any other routines it may leave the ...
The return value from a function is provided within the function by making an assignment to an identifier with the same name as the function. [5] However, some versions of Pascal provide a special function Exit(exp); that can be used to return a value immediately from a function, or, without parameters, to return immediately from a procedure. [6]
Additionally, a peek operation can, without modifying the stack, return the value of the last element added. The name stack is an analogy to a set of physical items stacked one atop another, such as a stack of plates. The order in which an element added to or removed from a stack is described as last in, first out, referred to by the acronym LIFO.
All return values are returned on the stack. This makes naive implementations slower than calling conventions that keep more values in registers. However, threaded code implementations that cache several of the top stack values in registers—in particular, the return address—are usually faster than subroutine calling conventions that always ...
The stack segment contains the call stack, a LIFO structure, typically located in the higher parts of memory. A "stack pointer" register tracks the top of the stack; it is adjusted each time a value is "pushed" onto the stack. The set of values pushed for one function call is termed a "stack frame". A stack frame consists at minimum of a return ...
At a minimum, a thread's stack is used to store the location of a return address provided by the caller in order to allow return statements to return to the correct location. The stack is often used to store variables of fixed length local to the currently active functions.
In computer programming, the return type (or result type) defines and constrains the data type of the value returned from a subroutine or method. [1] In many programming languages (especially statically-typed programming languages such as C , C++ , Java ) the return type must be explicitly specified when declaring a function.
For example, in the Java virtual machine (JVM), tail-recursive calls can be eliminated (as this reuses the existing call stack), but general tail calls cannot be (as this changes the call stack). [13] [14] As a result, functional languages such as Scala that target the JVM can efficiently implement direct tail recursion, but not mutual tail ...