mirror of
https://github.com/coreutils/coreutils.git
synced 2026-10-28 09:44:34 +08:00
Pádraig Brady
71419a36f7
There were no significant performance changes from the test cases
in commit a325c9978, but adding additional whitespace delimited cases
shows significant improvement. Below, with -f1, typical space delimited
input shows 4x more throughput, while the long line test shows 17x more.
Performance was tested with GCC 16 on an i7-5600U with
CFLAGS='-march=native -O3 -flto' with the following setup:
$ yes | head -n10M > sl.in
$ yes $(yes eeeaae | head -n10K | paste -s -d' ') | head -n10K > llw.in
$ yes $(yes eeeaae | head -n9 | paste -s -d' ') | head -n1M > asw.in
$ yes $(yes éééááé | head -n9 | paste -s -d$'\xe2\x80\x83') |
head -n1M > mbw.in
for type in sl llw asw mbw; do
cat $type.in >/dev/null;
for imp in '-before' '-after'; do
echo ============ "${imp:-base}" $type ==============;
for d in -w; do
fields='-f1 -f10 -f100'
test "$d" = "-b" && { fields='-b1 -b10 -b100'; d=''; }
test "$d" = "-c" && { fields='-c1 -c10 -c100'; d=''; }
for f in $fields; do
for loc in C.UTF-8; do
# Skip -b for UTF-8 as no different
test "$loc" = C.UTF-8 && echo "$f" | grep -q -- -b \
&& continue
# Skip multi-byte delimiter for C and not allowed
test "$loc" = C && test $(echo -n "$d" | wc -c) -ge 4 \
&& continue
bin=src/cut${imp}
LC_ALL=$loc $bin $f $d /dev/null 2>/dev/null &&
hyperfine --warmup=2 -m2 -M6 \
"LC_ALL=$loc $bin $f $d $type.in >/dev/null" ||
printf 'Benchmark 1: %s\n unsupported\n\n' \
"LC_ALL=$loc $bin $f $d $type.in >/dev/null"
done;
done;
done;
done;
done
After a little post-processing of the results, we get:
-- src/cut-before
| command | sl | llw | asw | mbw |
| --------------- | -------- | -------- | -------- | -------- |
| UTF8 -f1 -w | 96.2 ms | 1.916 s | 190.6 ms | 906.5 ms |
| UTF8 -f10 -w | 104.6 ms | 1.921 s | 187.7 ms | 845.6 ms |
| UTF8 -f100 -w | 104.4 ms | 1.916 s | 187.4 ms | 846.4 ms |
-- src/cut-after
| command | sl | llw | asw | mbw |
| --------------- | -------- | -------- | -------- | -------- |
| UTF8 -f1 -w | 88.7 ms | 112.4 ms | 43.5 ms | 146.3 ms |
| UTF8 -f10 -w | 95.2 ms | 114.4 ms | 193.5 ms | 848.4 ms |
| UTF8 -f100 -w | 94.8 ms | 130.6 ms | 194.4 ms | 848.1 ms |
* src/cut.c (scan_mb_line_end): A new function to skip
to EOL once we have exhausted the field selection.
(cut_fields_mb_any): Only skip after recognizing a field delimiter.
* tests/cut/cut.pl: Add test cases.
* tests/cut/mb-non-utf8.sh: Likewise.
* NEWS: Mention the improvement.