source: kBuild/trunk/src/grep/tests/mb-non-UTF8-performance

#!/bin/sh
# grep-2.17 would take nearly 200x longer to run the command below.
# The 200x is on an Intel i7-based system.
# On an AMD FX-4100, it would take up to 2500x longer.

# Copyright 2014-2021 Free Software Foundation, Inc.

# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.

# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.

. "${srcdir=.}/init.sh"; path_prepend_ ../src

fail=0

# This test is susceptible to failure due to differences in
# system load during the two test runs, so we'll mark it as
# "expensive", making it less likely to be run by regular users.
expensive_

# Make the input large enough so that even on high-end systems
# the unibyte test takes at least 10ms of user time.
n_lines=100000
while :; do
  yes $(printf '%078d' 0) | sed ${n_lines}q > in || framework_failure_
  ubyte_ms=$(LC_ALL=C user_time_ 1 grep -i foobar in) || fail=1
  test $ubyte_ms -ge 10 && break
  n_lines=$(expr $n_lines + 200000)
done

require_JP_EUC_locale_
mbyte_ms=$(user_time_ 1 grep -i foobar in) || fail=1

# The duration of the multi-byte run must be no more than 30 times
# that of the single-byte one.
# A multiple of 3 seems to be enough for i5,i7, but AMD needs >25.
returns_ 1 expr $ubyte_ms '<' $mbyte_ms / 30 || fail=1

Exit $fail