WARNING - THIS SUGGESTION IS FRAUGHT WITH PERIL
Use this at your own risk. I am not responsible if you get fired.

You could unroll the function call stack (using goto and dynamic labels) and manipulate it yourself. This is ... very poor form, requires a book of comments, and is about as fragile as bone china. But, it is possible.

Let's say you have:

my $value = foo( 3, 4, 5 );

for ( 1 .. 10_000 ) {
    # Blahblah
    my $inside_value = foo( $_, 1, 2 );
    # Yadda, yadda, yadda
}

my $other_value = foo( 7, 8, 9 );

sub foo {
    my ($first, @args) = @_;
    do_something( $first );
    return do_something_else( @args );
}
[download]

my $LABEL;
my @FOO_ARGS;
my $FOO_RV;

$LABEL = 'FIRST';
@FOO_ARGS = ( 3, 4, 5 );
goto FOO;
FIRST:
my $value = $FOO_RV;
$LABEL = undef; $FOO_RV = undef;

for ( 1 .. 10_000 ) {
    # Blahblah

    @FOO_ARGS = ( $_, 1, 2 );
    FOO: {
        my ($first, @args) = @FOO_ARGS;
        do_something( $first );
        $FOO_RV = do_something_else( @args );
        goto $LABEL if $LABEL;
    }
    my $inside_value = $FOO_RV;

    # Yadda, yadda, yadda
}

$LABEL = 'SECOND';
@FOO_ARGS = ( 7, 8, 9 );
goto FOO;
SECOND:
my $other_value = $FOO_RV;
$LABEL = undef; $FOO_RV = undef;
[download]

Note: I am not advocating this type of code nor am I suggesting that you won't be hunted down like the fool you are if you implement this code and quit the next day. I'm saying that you can inline functions in Perl that are called from outside the loop and here is how.