Re: help wanted reproducing reported performance regression in groff 1.24

[Deri via discussion of the GNU roff typesetting system and related software]

Using Dimich script:-

  1     0.02    0.02
  2     0.04    0.06
  4     0.08    0.13
  8     0.16    0.40
 16     0.34    1.28
 32     0.66    4.73
 64     1.35    18.19

This script is measuring grotty's performance only.

Your script:

find data in 68145a.*.dat 
n       1.23.0  1.24.0 
1       0.09    0.12 
2       0.17    0.23 
3       0.25    0.32 
4       0.30    0.45 
5       0.37    0.56 
6       0.44    0.68 
7       0.52    0.87 
8       0.59    0.97 
9       0.67    1.18 
10      0.74    1.35 
11      0.82    1.53 
12      0.90    1.73 
13      0.95    1.98 
14      1.03    2.21 
15      1.10    2.43 
16      1.20    2.71 
17      1.24    2.92 
18      1.32    3.17 
19      1.40    3.33 
20      1.47    3.63

This script is timing the whole pipeline. Running your script with extra-args 
set to -Z:-

find data in 68145a.*.dat
n       1.23.0  1.24.0
1       0.06    0.09
2       0.12    0.17
3       0.18    0.22
4       0.20    0.29
5       0.25    0.37
6       0.31    0.44
7       0.36    0.52
8       0.42    0.58
9       0.47    0.67
10      0.51    0.74
11      0.60    0.81
12      0.62    0.89
13      0.68    0.95
14      0.76    1.03
15      0.80    1.10
16      0.83    1.20
17      0.88    1.28
18      0.93    1.32
19      0.99    1.43
20      1.03    1.50

So although 1.24 man.tmac is slower it is not quadratic so the real performance 
hit is in grotty. 


Cheers

Deri