Commit | Line | Data |
58d76dfd |
1 | #!./perl -w |
2 | # Now they'll be wanting biff! and zap! tests too. |
3 | |
4 | BEGIN { |
5 | chdir 't' if -d 't'; |
6 | @INC = '../lib'; |
7 | require './test.pl'; |
8 | } |
9 | |
10 | # This calcualtion ought to be within 0.001 of the right answer. |
11 | my $bits_in_uv = int (0.001 + log (~0+1) / log 2); |
12 | |
13 | # 3**30 < 2**48, don't trust things outside that range on a Cray |
14 | # Likewise other 3 should not overflow 48 bits if I did my sums right. |
15 | my @pow = ([3,30,1e-14], [4,32,0], [5,20,1e-14], [2.5, 10,,1e-14], [-2, 69,0]); |
16 | my $tests; |
17 | $tests += $_->[1] foreach @pow; |
18 | |
19 | plan tests => 1 + $bits_in_uv + $tests; |
20 | |
21 | # Ought to be 32, 64, 36 or something like that. |
22 | |
23 | my $remainder = $bits_in_uv & 3; |
24 | |
25 | cmp_ok ($remainder, '==', 0, 'Sanity check bits in UV calculation') |
26 | or printf "# ~0 is %d (0x%d) which gives $bits_in_uv bits\n", ~0, ~0; |
27 | |
28 | # These are a lot of brute force tests to see how accurate $m ** $n is. |
29 | # Unfortunately rather a lot of perl programs expect 2 ** $n to be integer |
30 | # perfect, forgetting that it's a call to floating point pow() which never |
31 | # claims to deliver perfection. |
32 | foreach my $n (0..$bits_in_uv - 1) { |
33 | my $exp = 2 ** $n; |
34 | my $int = 1 << $n; |
35 | cmp_ok ($exp, '==', $int, "2 ** $n vs 1 << $n"); |
36 | } |
37 | |
38 | foreach my $pow (@pow) { |
39 | my ($base, $max, $range) = @$pow; |
40 | my $fp = 1; |
41 | foreach my $n (0..$max-1) { |
42 | my $exp = $base ** $n; |
43 | within ($exp, $fp, $range, "$base ** $n [$exp] vs $base * $base * ..."); |
44 | $fp *= $base; |
45 | } |
46 | } |