sub ba2bi3 {
	my $ba = pack 'C*', (@_, (0) x (4 - ( @_ % 4 || 4 ) ) );
	my $result = Math::BigInt->new(0);
	my $p  = length($ba) - 4;
	do {
		$result <<= 32; #!4294967296;
		$result += unpack 'V', substr $ba, $p , 4;
	} while ($p-=4) >= 0;
	$result;
}

print ba2bi3( bigint_to_bytearray( Math::BigInt->new('1234567890' x 8) ) );

##</code><code>##

11: +1234567890 <<Length and value under test
Benchmark:
running
 best, clean, new, org , each for at least 10 CPU seconds
      best: 11 wallclock secs (10.59 usr +  0.00 sys = 10.59 CPU) @ 208.58/s (n=2208)
     clean: 11 wallclock secs (10.55 usr +  0.00 sys = 10.55 CPU) @ 213.94/s (n=2256)
       new: 11 wallclock secs (10.51 usr +  0.00 sys = 10.51 CPU) @ 60.26/s (n=633)
       org: 11 wallclock secs (10.35 usr +  0.00 sys = 10.35 CPU) @ 24.36/s (n=252)

        Rate   org   new  best clean
org   24.4/s    --  -60%  -88%  -89%
new   60.3/s  147%    --  -71%  -72%
best   209/s  756%  246%    --   -3%
clean  214/s  778%  255%    3%    --
The results are the same

##</code><code>##

301: +1234567890123456789012345678901234567890
1234567890123456789012345678901234567890
1234567890123456789012345678901234567890
1234567890123456789012345678901234567890
1234567890123456789012345678901234567890
1234567890123456789012345678901234567890
1234567890123456789012345678901234567890
12345678901234567890
Benchmark:
running best, clean, new, org , each for at least 10 CPU seconds

...
      s/iter   org   new clean  best
org     5.82    --  -77%  -94%  -94%
new     1.31  344%    --  -73%  -73%
clean  0.352 1555%  273%    --   -1%
best   0.349 1569%  276%    1%    --
The results are the same

##</code><code>##

C:\test>229290
Name "main::ba" used only once: possible typo at C:\test\229290.pl line 67.
301: +12345678901234567890123456789012345678901234567890
12345678901234567890123456789012345678901234567890
12345678901234567890123456789012345678901234567890
12345678901234567890123456789012345678901234567890
12345678901234567890123456789012345678901234567890
12345678901234567890123456789012345678901234567890
Benchmark: running best, clean, demerphq, new, org , each for at least 10 CPU seconds

            Rate      org      new    clean demerphq     best
org      0.173/s       --     -78%     -94%     -94%     -94%
new      0.770/s     345%       --     -73%     -73%     -73%
clean     2.83/s    1533%     267%       --      -1%      -1%
demerphq  2.86/s    1553%     272%       1%       --      -0%
best      2.86/s    1553%     272%       1%       0%       --
The results are the same