I believe you can do the complete calculation without conversion and just at the end downgrade to 32 bit and convert to signed. The following should work:

sub calc_32bit_signed( $value ) {
    return unpack( "l", pack "L", ($value & 0xffffffff)))
}

...

say calc_32bit_signed( $n << 6 );
say calc_32bit_signed( $n + 2 );

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In reply to Re^3: Trying to translate overflowing JS code to Perl by Corion
in thread Trying to translate overflowing JS code to Perl by bliako

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