Product Code Database
In programming, a call site of a function or subroutine is the location (line of code) where the function is called (or may be called, through dynamic dispatch). A call site is where zero or more arguments are passed to the function, and zero or more are received.
// this is a function ''definition''
function sqr(x)
{
return x * x;
}
function foo() {
// these are two call sites of function sqr in this function
a = sqr(b);
c = sqr(b);
}
* (usually) external call.... R13 usually points to a save area for general purpose registers beforehand
* and R1 points to a list of addresses of parameters (if any)
LA R1,=A(B) point to (address of) variable 'B'
L R15,=A(SQR) Load pointer (address constant) to separately compiled/assembled subroutine
BALR R14,R15 Go to subroutine, which returns - usually at zero displacement on R14
* internal call (usually much smaller overhead and possibly 'known' parameters)
BAL R14,SQR Go to program label and return
BAL R14,SQR Go to program label and return (using offset on R14 as return address)
B OK (RET+0) - O.K
* (RET+4) - Failure
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