[Bug]: Duplicate BIRNonTerminator.TypeCast instruction when passing arguments to a method with complex Varargs type parameter

[Thushara-Piyasekara]

Description

When passing arguments to a complex Varargs type parameter, BIRGen phase generate a duplicate BIRNonTerminator.TypeCast instruction. This duplicate instruction can be removed for better runtime performance.

Steps to Reproduce

See the following example,

public function main() {
    bar("hello");
}

function bar(string|int... item) {

}

use bal build --dump-bir to see the BIR instructions,

public main function() -> () {
    %0(RETURN) ();
    %1(TEMP) string|int[];
    %2(TEMP) int;
    %3(TEMP) string|int;
    %4(TEMP) string|int;
    %5(TEMP) string;
    %6(TEMP) ();

    bb0 {
        %2 = ConstLoad -1;
        %5 = ConstLoad hello;
        %4 = <string|int> %5;
        %3 = <string|int> %4;
        %1 = newArray string|int[][%2]{%3};
        %6 = bar(%1) -> bb1;
    }
    bb1 {
        %0 = ConstLoad 0;
        GOTO bb2;
    }
    bb2 {
        return;
    }
}

In bb0 following duplicate instructions can be found,

        %4 = <string|int> %5;
        %3 = <string|int> %4;

Same duplicate instructions can be found when debugging the BIRgen phase,

Affected Version(s)

Ballerina 2201.9.0 (Swan Lake Update 9) SNAPSHOT

OS, DB, other environment details and versions

No response

Related area

-> Compilation

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