[PATCH] benchtests: Add strtok benchmark
Rajalakshmi Srinivasaraghavan
raji@linux.vnet.ibm.com
Mon Nov 11 16:47:00 GMT 2013
On 11/11/2013 07:22 PM, Will Newton wrote:
> On 11 November 2013 13:33, Rajalakshmi Srinivasaraghavan
> <raji@linux.vnet.ibm.com> wrote:
>> On 11/11/2013 05:16 PM, Will Newton wrote:
>>> On 11 November 2013 11:36, Rajalakshmi Srinivasaraghavan
>>> <raji@linux.vnet.ibm.com> wrote:
>>>> Hi All,
>>>>
>>>> This patch adds a benchtest for 'strtok'.
>>>>
>>>> * benchtests/Makefile: Add bench-strtok.
>>>> * benchtests/bench-strtok.c: New file: strtok benchtest.
>>>> * benchtests/bench-strtok-ifunc.c: New file: strtok benchtest.
>>>>
>>>> Signed-off-by: Rajalakshmi Srinivasaraghavan <raji@linux.vnet.ibm.com>
>>>> ---
>>>> benchtests/Makefile | 2 +-
>>>> benchtests/bench-strtok-ifunc.c | 20 ++++
>>>> benchtests/bench-strtok.c | 205
>>>> ++++++++++++++++++++++++++++++++++++++++
>>>> 3 files changed, 226 insertions(+), 1 deletion(-)
>>>> create mode 100644 benchtests/bench-strtok-ifunc.c
>>>> create mode 100644 benchtests/bench-strtok.c
>>> Thanks for doing this work! I have one question below...
>>>
>>>> diff --git a/benchtests/Makefile b/benchtests/Makefile
>>>> index aec395a..dabad81 100644
>>>> --- a/benchtests/Makefile
>>>> +++ b/benchtests/Makefile
>>>> @@ -28,7 +28,7 @@ string-bench := bcopy bzero memccpy memchr memcmp
>>>> memcpy memmem memmove \
>>>> mempcpy memset rawmemchr stpcpy stpncpy strcasecmp
>>>> strcasestr \
>>>> strcat strchr strchrnul strcmp strcpy strcspn strlen \
>>>> strncasecmp strncat strncmp strncpy strnlen strpbrk
>>>> strrchr \
>>>> - strspn strstr strcpy_chk stpcpy_chk memrchr
>>>> + strspn strstr strcpy_chk stpcpy_chk memrchr strtok
>>>> string-bench-ifunc := $(addsuffix -ifunc, $(string-bench))
>>>> string-bench-all := $(string-bench) $(string-bench-ifunc)
>>>>
>>>> diff --git a/benchtests/bench-strtok-ifunc.c
>>>> b/benchtests/bench-strtok-ifunc.c
>>>> new file mode 100644
>>>> index 0000000..edcca9b
>>>> --- /dev/null
>>>> +++ b/benchtests/bench-strtok-ifunc.c
>>>> @@ -0,0 +1,20 @@
>>>> +/* Measure IFUNC implementations of strtok function.
>>>> + Copyright (C) 2013 Free Software Foundation, Inc.
>>>> + This file is part of the GNU C Library.
>>>> +
>>>> + The GNU C Library is free software; you can redistribute it and/or
>>>> + modify it under the terms of the GNU Lesser General Public
>>>> + License as published by the Free Software Foundation; either
>>>> + version 2.1 of the License, or (at your option) any later version.
>>>> +
>>>> + The GNU C Library 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
>>>> + Lesser General Public License for more details.
>>>> +
>>>> + You should have received a copy of the GNU Lesser General Public
>>>> + License along with the GNU C Library; if not, see
>>>> + <http://www.gnu.org/licenses/>. */
>>>> +
>>>> +#define TEST_IFUNC 1
>>>> +#include "bench-strtok.c"
>>>> diff --git a/benchtests/bench-strtok.c b/benchtests/bench-strtok.c
>>>> new file mode 100644
>>>> index 0000000..bd937e5
>>>> --- /dev/null
>>>> +++ b/benchtests/bench-strtok.c
>>>> @@ -0,0 +1,205 @@
>>>> +/* Measure strtok functions.
>>>> + Copyright (C) 2013 Free Software Foundation, Inc.
>>>> + This file is part of the GNU C Library.
>>>> +
>>>> + The GNU C Library is free software; you can redistribute it and/or
>>>> + modify it under the terms of the GNU Lesser General Public
>>>> + License as published by the Free Software Foundation; either
>>>> + version 2.1 of the License, or (at your option) any later version.
>>>> +
>>>> + The GNU C Library 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
>>>> + Lesser General Public License for more details.
>>>> +
>>>> + You should have received a copy of the GNU Lesser General Public
>>>> + License along with the GNU C Library; if not, see
>>>> + <http://www.gnu.org/licenses/>. */
>>>> +
>>>> +#define TEST_MAIN
>>>> +#define TEST_NAME "strtok"
>>>> +#include "bench-string.h"
>>>> +
>>>> +char *
>>>> +simple_strtok (char *s1, char *s2)
>>>> +{
>>>> + static char *saveptr;
>>>> + char *token;
>>>> + ssize_t i = 0, j = 0;
>>>> + int found = 0;
>>>> + size_t s2len = strlen (s2);
>>>> +
>>>> + if (s1 == NULL)
>>>> + s1 = saveptr;
>>>> + if (s1 == NULL || *s1 == '\0')
>>>> + return NULL;
>>>> +
>>>> + while (!found)
>>>> + {
>>>> + if (s1[i] == '\0')
>>>> + {
>>>> + saveptr = NULL;
>>>> + return NULL;
>>>> + }
>>>> + for (j = 0; j < s2len; j++)
>>>> + {
>>>> + if (s1[i] == s2[j])
>>>> + {
>>>> + i++;
>>>> + found = 0;
>>>> + break;
>>>> + }
>>>> + found = 1;
>>>> + }
>>>> + }
>>>> + token = s1 + i;
>>>> + i++;
>>>> + found = 0;
>>>> + while (!found)
>>>> + {
>>>> + if (s1[i] == '\0')
>>>> + {
>>>> + saveptr = NULL;
>>>> + return token;
>>>> + }
>>>> + for (j = 0; j < s2len; j++)
>>>> + {
>>>> + if (s1[i] == s2[j])
>>>> + {
>>>> + found = 1;
>>>> + break;
>>>> + }
>>>> + }
>>>> + i++;
>>>> + }
>>>> + s1[i - 1] = '\0';
>>>> + saveptr = s1 + i;
>>>> + return token;
>>>> +}
>>>> +
>>>> +typedef char *(*proto_t) (const char *, const char *);
>>>> +
>>>> +IMPL (simple_strtok, 0)
>>>> +IMPL (strtok, 1)
>>>> +
>>>> +static void
>>>> +do_one_test (impl_t * impl, const char *s1, const char *s2)
>>>> +{
>>>> + size_t i, iters = INNER_LOOP_ITERS;
>>>> + timing_t start, stop, cur;
>>>> + TIMING_NOW (start);
>>>> + for (i = 0; i < iters; ++i)
>>>> + {
>>>> + CALL (impl, s1, s2);
>>>> + CALL (impl, NULL, s2);
>>>> + CALL (impl, NULL, s2);
>>>> + }
>>>> + TIMING_NOW (stop);
>>>> +
>>>> + TIMING_DIFF (cur, start, stop);
>>>> +
>>>> + TIMING_PRINT_MEAN ((double) cur, (double) iters);
>>>> +
>>>> +}
>>>> +
>>>> +
>>>> +static void
>>>> +do_test (size_t align1, size_t align2, size_t len1, size_t len2, int
>>>> fail)
>>>> +{
>>>> + char *s2 = (char *) (buf2 + align2);
>>>> + static const char d[] = "1234567890abcdef";
>>>> +#define dl (sizeof (d) - 1)
>>>> + char *ss2 = s2;
>>>> + for (size_t l = len2; l > 0; l = l > dl ? l - dl : 0)
>>>> + {
>>>> + size_t t = l > dl ? dl : l;
>>>> + ss2 = mempcpy (ss2, d, t);
>>>> + }
>>>> + s2[len2] = '\0';
>>>> +
>>>> + printf ("Length %4zd/%zd, alignment %2zd/%2zd, %s:",
>>>> + len1, len2, align1, align2, fail ? "fail" : "found");
>>>> +
>>>> + FOR_EACH_IMPL (impl, 0)
>>>> + {
>>>> + char *s1 = (char *) (buf1 + align1);
>>>> + if (fail)
>>>> + {
>>>> + char *ss1 = s1;
>>>> + for (size_t l = len1; l > 0; l = l > dl ? l - dl : 0)
>>>> + {
>>>> + size_t t = l > dl ? dl : l;
>>>> + memcpy (ss1, d, t);
>>>> + ++ss1[len2 > 7 ? 7 : len2 - 1];
>>>> + ss1 += t;
>>>> + }
>>>> + }
>>>> + else
>>>> + {
>>>> + memset (s1, '0', len1);
>>>> + memcpy (s1 + (len1 - len2) - 2, s2, len2);
>>>> + if ((len1 / len2) > 4)
>>>> + memcpy (s1 + (len1 - len2) - (3 * len2), s2, len2);
>>>> + }
>>>> + s1[len1] = '\0';
>>>> + do_one_test (impl, s1, s2);
>>>> + }
>>>> + putchar ('\n');
>>>> +}
>>>> +
>>>> +static int
>>>> +test_main (void)
>>>> +{
>>>> + test_init ();
>>>> +
>>>> + printf ("%23s", "");
>>>> + FOR_EACH_IMPL (impl, 0)
>>>> + printf ("\t%s", impl->name);
>>>> + putchar ('\n');
>>>> +
>>>> + for (size_t klen = 2; klen < 32; ++klen)
>>>> + for (size_t hlen = 2 * klen; hlen < 16 * klen; hlen += klen)
>>>> + {
>>>> + do_test (0, 0, hlen, klen, 0);
>>>> + do_test (0, 0, hlen, klen, 1);
>>>> + do_test (0, 3, hlen, klen, 0);
>>>> + do_test (0, 3, hlen, klen, 1);
>>>> + do_test (0, 9, hlen, klen, 0);
>>>> + do_test (0, 9, hlen, klen, 1);
>>>> + do_test (0, 15, hlen, klen, 0);
>>>> + do_test (0, 15, hlen, klen, 1);
>>>> +
>>>> + do_test (3, 0, hlen, klen, 0);
>>>> + do_test (3, 0, hlen, klen, 1);
>>>> + do_test (3, 3, hlen, klen, 0);
>>>> + do_test (3, 3, hlen, klen, 1);
>>>> + do_test (3, 9, hlen, klen, 0);
>>>> + do_test (3, 9, hlen, klen, 1);
>>>> + do_test (3, 15, hlen, klen, 0);
>>>> + do_test (3, 15, hlen, klen, 1);
>>>> +
>>>> + do_test (9, 0, hlen, klen, 0);
>>>> + do_test (9, 0, hlen, klen, 1);
>>>> + do_test (9, 3, hlen, klen, 0);
>>>> + do_test (9, 3, hlen, klen, 1);
>>>> + do_test (9, 9, hlen, klen, 0);
>>>> + do_test (9, 9, hlen, klen, 1);
>>>> + do_test (9, 15, hlen, klen, 0);
>>>> + do_test (9, 15, hlen, klen, 1);
>>>> +
>>>> + do_test (15, 0, hlen, klen, 0);
>>>> + do_test (15, 0, hlen, klen, 1);
>>>> + do_test (15, 3, hlen, klen, 0);
>>>> + do_test (15, 3, hlen, klen, 1);
>>>> + do_test (15, 9, hlen, klen, 0);
>>>> + do_test (15, 9, hlen, klen, 1);
>>>> + do_test (15, 15, hlen, klen, 0);
>>>> + do_test (15, 15, hlen, klen, 1);
>>>> + }
>>> How were these alignment values chosen? It seems a strange selection
>>> (I know other string benchmarks seem to be afflicted by this as well).
>>>
>> I selected them from strstr benchmark.
>> If you have a better selection, I can change this.
> Unfortunately I don't have a ready made set of alignments that would
> be good and it really requires some thought to come up with a good
> representative set of alignments.
>
> This benchmark is obviously much better than having no benchmark at
> all but I would like to see the existing alignments used either
> documented or improved if possible.
>
Yes, There can be a separate task in future to analyze and find all
effective combinations
of alignment numbers which can be applied to all string functions.
--
Thanks
Raji
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