Today we continue our discussion on the method calls from the WRL research report on the Swift Java compiler. The Swift IR has operations to represent the different method invocations in Java such as class method calls, instance method calls, and interface calls. Class method calls are like procedural calls. Values representing method calls  all take the method arguments as inputs as well as the current global store. A null check on the receiver object is included before any instance method invocation,
Most method calls produce a  program result, as well as, producing a new global store. In order to foliow the rule that  each value in the SSA graph produce a single result, method calls produce a tuple which consists of the method results and the new global store. The two components are individually projected as required Values representing the method calls are followed by one or two select calls in the SSA graph.
If a method can cause an exception that is caught in the current method, the call actually produces a distinct global store for each normal and exception successor edge, since the state of memory be different in either case. In the most common case, when no exception of the method call is caught, no extra store is required since the exception exit will not access the global store.
There are arguments in the entry block for the incoming global store of a method call and in the case of an instance method, the first argument is the receiver. The compiler therefore automatically uses the null-check argument when a null-check of the receiver is required so there is no machine code corresponding to this check.
The handling of the store and null check arguments above is conducive to method inlining. To do so , the compiler builds the IR of the original method and the called method The CFG and the SSA graph of the called method are inserted into the CFG and the SSA graph of the calling method at the point of the call, with the arguments of the method body of the inlined method replaced by the corresponding arguments to the method call. These arguments include the global store and the null check of the receiver object This matching process establishes the correct dependences so that all the values within the inlined SSA graph can now be moved anywhere allowed by the usual dependence rules.
If a method has no write operations, then the operations that were below this call will be using the store from above this call because the method returns the original store in the return operation. Therefore there will be optimizations given that the method has no side-effects.

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#codingexercise
Double GetAlternateEvenNumberRangeSumFourthPowerRootSquare (Double [] A)
{
if (A == null) return 0;
Return A.AlternateEvenNumberRangeSumFourthPowerRootSquare();
}