This is perl 5.6.1

          Rate our_e our_g  my_e explicit  my_g greedy our_u unpackA m
+y_u substr
our_e    126/s    --   -9%  -20%     -25%  -28%   -33%  -37%    -49% -
+54%   -56%
our_g    139/s   10%    --  -11%     -17%  -21%   -26%  -30%    -44% -
+49%   -52%
my_e     158/s   25%   13%    --      -6%  -10%   -17%  -21%    -36% -
+42%   -45%
explicit 168/s   33%   20%    6%       --   -5%   -12%  -16%    -32% -
+38%   -42%
my_g     175/s   39%   26%   11%       5%    --    -7%  -12%    -29% -
+36%   -39%
greedy   189/s   50%   36%   20%      13%    8%     --   -5%    -24% -
+30%   -34%
our_u    199/s   58%   43%   26%      19%   13%     5%    --    -20% -
+27%   -31%
unpackA  248/s   96%   78%   57%      48%   41%    31%   25%      --  
+-9%   -14%
my_u     272/s  116%   95%   73%      63%   55%    44%   37%     10%  
+ --    -5%
substr   288/s  128%  106%   83%      72%   64%    52%   45%     16%  
+ 6%     --
[download]

And the same computer with perl 5.8.3 is _much_ slower.

           Rate our_e our_g  my_e our_u my_g explicit unpackA greedy m
+y_u substr
our_e    61.0/s    --   -9%  -25%  -29% -33%     -41%    -48%   -48% -
+52%   -67%
our_g    67.3/s   10%    --  -17%  -21% -27%     -35%    -42%   -43% -
+47%   -64%
my_e     80.7/s   32%   20%    --   -5% -12%     -22%    -31%   -32% -
+36%   -57%
our_u    85.3/s   40%   27%    6%    --  -7%     -18%    -27%   -28% -
+32%   -54%
my_g     91.6/s   50%   36%   13%    7%   --     -12%    -21%   -23% -
+28%   -51%
explicit  104/s   70%   54%   28%   22%  13%       --    -11%   -12% -
+18%   -44%
unpackA   116/s   91%   73%   44%   36%  27%      12%      --    -2%  
+-8%   -37%
greedy    118/s   94%   76%   47%   39%  29%      14%      2%     --  
+-6%   -36%
my_u      126/s  107%   88%   57%   48%  38%      22%      9%     7%  
+ --   -32%
substr    186/s  205%  176%  130%  118% 103%      79%     60%    57%  
+47%     --
[download]