Re: [PATCH v1 1/5] benchtests: Improve bench-strrchr

["H.J. Lu" <hjl.tools@gmail.com>]

On Wed, Apr 20, 2022 at 8:14 PM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
>
> 1. Use json-lib for printing results.
> 2. Expose all parameters (before pos, seek_char, and max_char where
>    not printed).
> 3. Add benchmarks that test multiple occurence of seek_char in the
>    string.
> ---
>  benchtests/bench-strrchr.c | 126 ++++++++++++++++++++++++-------------
>  1 file changed, 82 insertions(+), 44 deletions(-)
>
> diff --git a/benchtests/bench-strrchr.c b/benchtests/bench-strrchr.c
> index abdae60c51..cceea77e1b 100644
> --- a/benchtests/bench-strrchr.c
> +++ b/benchtests/bench-strrchr.c
> @@ -23,6 +23,7 @@
>  # define TEST_NAME "strrchr"
>  #endif
>  #include "bench-string.h"
> +#include "json-lib.h"
>
>  #define BIG_CHAR MAX_CHAR
>
> @@ -53,7 +54,8 @@ SIMPLE_STRRCHR (const CHAR *s, int c)
>  }
>
>  static void
> -do_one_test (impl_t *impl, const CHAR *s, int c, CHAR *exp_res)
> +do_one_test (json_ctx_t *json_ctx, impl_t *impl, const CHAR *s, int c,
> +            CHAR *exp_res)
>  {
>    CHAR *res = CALL (impl, s, c);
>    size_t i, iters = INNER_LOOP_ITERS8;
> @@ -61,8 +63,8 @@ do_one_test (impl_t *impl, const CHAR *s, int c, CHAR *exp_res)
>
>    if (res != exp_res)
>      {
> -      error (0, 0, "Wrong result in function %s %p %p", impl->name,
> -            res, exp_res);
> +      error (0, 0, "Wrong result in function %s %p %p", impl->name, res,
> +            exp_res);

These changes aren't needed.

>        ret = 1;
>        return;
>      }
> @@ -72,24 +74,28 @@ do_one_test (impl_t *impl, const CHAR *s, int c, CHAR *exp_res)
>      {
>        CALL (impl, s, c);
>      }
> -  TIMING_NOW (stop);
>
> +  TIMING_NOW (stop);

Not needed.

>    TIMING_DIFF (cur, start, stop);
>
> -  TIMING_PRINT_MEAN ((double) cur, (double) iters);
> +  json_element_double (json_ctx, (double) cur / (double) iters);
> +  return;

Return isn't needed.

>  }
>
>  static void
> -do_test (size_t align, size_t pos, size_t len, int seek_char, int max_char)
> +do_test (json_ctx_t *json_ctx, size_t align, size_t pos, size_t len,
> +        int seek_char, int max_char, size_t freq)
>  /* For wcsrchr: align here means align not in bytes,
>     but in wchar_ts, in bytes it will equal to align * (sizeof (wchar_t))
>     len for wcschr here isn't in bytes but it's number of wchar_t symbols.  */
>  {
>    size_t i;
> +  size_t pos_chunk_sz = freq ? (pos / freq) : pos;
> +  size_t last_pos = len;
>    CHAR *result;
>    CHAR *buf = (CHAR *) buf1;
>
> -  align &= 7;
> +  align &= (getpagesize () - 1);

If we have such large alignments, the tests may be skipped.
Should we change it to 127 instead?

>    if ((align + len) * sizeof (CHAR) >= page_size)
>      return;
>
> @@ -103,6 +109,16 @@ do_test (size_t align, size_t pos, size_t len, int seek_char, int max_char)
>        if ((i > pos || pos >= len) && buf[align + i] == seek_char)
>         buf[align + i] = seek_char + 10 + (random () & 15);
>      }
> +
> +  if (pos_chunk_sz == 0 && pos)
> +    pos_chunk_sz = 1;
> +
> +  for (i = pos_chunk_sz; i < pos && i < len; i += pos_chunk_sz)
> +    {
> +      buf[align + i] = seek_char;
> +      last_pos = i;
> +    }
> +
>    buf[align + len] = 0;
>
>    if (pos < len)
> @@ -110,66 +126,88 @@ do_test (size_t align, size_t pos, size_t len, int seek_char, int max_char)
>        buf[align + pos] = seek_char;
>        result = (CHAR *) (buf + align + pos);
>      }
> +  else if (last_pos < len)
> +    result = (CHAR *) (buf + align + last_pos);
>    else if (seek_char == 0)
>      result = (CHAR *) (buf + align + len);
>    else
>      result = NULL;
>
> -  printf ("Length %4zd, alignment in bytes %2zd:", len, align * sizeof (CHAR));
> +  json_element_object_begin (json_ctx);
> +  json_attr_uint (json_ctx, "len", len);
> +  json_attr_uint (json_ctx, "pos", pos);
> +  json_attr_uint (json_ctx, "align", align);
> +  json_attr_uint (json_ctx, "freq", freq);
> +  json_attr_uint (json_ctx, "seek", seek_char);
> +  json_attr_uint (json_ctx, "max_char", max_char);
> +  json_array_begin (json_ctx, "timings");
>
>    FOR_EACH_IMPL (impl, 0)
> -    do_one_test (impl, (CHAR *) (buf + align), seek_char, result);
> +    do_one_test (json_ctx, impl, (CHAR *) (buf + align), seek_char, result);
>
> -  putchar ('\n');
> +  json_array_end (json_ctx);
> +  json_element_object_end (json_ctx);
>  }
>
>  int
>  test_main (void)
>  {
> -  size_t i;
> +  json_ctx_t json_ctx;
> +  size_t i, j;
> +  int seek;
>
>    test_init ();
> +  json_init (&json_ctx, 0, stdout);
>
> -  printf ("%20s", "");
> -  FOR_EACH_IMPL (impl, 0)
> -    printf ("\t%s", impl->name);
> -  putchar ('\n');
> +  json_document_begin (&json_ctx);
> +  json_attr_string (&json_ctx, "timing_type", TIMING_TYPE);
>
> -  for (i = 1; i < 8; ++i)
> -    {
> -      do_test (0, 16 << i, 2048, 23, SMALL_CHAR);
> -      do_test (i, 16 << i, 2048, 23, SMALL_CHAR);
> -    }
> +  json_attr_object_begin (&json_ctx, "functions");
> +  json_attr_object_begin (&json_ctx, TEST_NAME);
> +  json_attr_string (&json_ctx, "bench-variant", "");
>
> -  for (i = 1; i < 8; ++i)
> -    {
> -      do_test (i, 64, 256, 23, SMALL_CHAR);
> -      do_test (i, 64, 256, 23, BIG_CHAR);
> -    }
> -
> -  for (i = 0; i < 32; ++i)
> -    {
> -      do_test (0, i, i + 1, 23, SMALL_CHAR);
> -      do_test (0, i, i + 1, 23, BIG_CHAR);
> -    }
> +  json_array_begin (&json_ctx, "ifuncs");
> +  FOR_EACH_IMPL (impl, 0)
> +    json_element_string (&json_ctx, impl->name);
> +  json_array_end (&json_ctx);
>
> -  for (i = 1; i < 8; ++i)
> -    {
> -      do_test (0, 16 << i, 2048, 0, SMALL_CHAR);
> -      do_test (i, 16 << i, 2048, 0, SMALL_CHAR);
> -    }
> +  json_array_begin (&json_ctx, "results");
>
> -  for (i = 1; i < 8; ++i)
> +  for (seek = 0; seek <= 23; seek += 23)
>      {
> -      do_test (i, 64, 256, 0, SMALL_CHAR);
> -      do_test (i, 64, 256, 0, BIG_CHAR);
> +      for (j = 1; j < 32; j += j)
> +       {
> +         for (i = 1; i < 9; ++i)
> +           {
> +             do_test (&json_ctx, 0, 16 << i, 2048, seek, SMALL_CHAR, j);
> +             do_test (&json_ctx, i, 16 << i, 2048, seek, SMALL_CHAR, j);
> +           }
> +
> +         for (i = 1; i < 8; ++i)
> +           {
> +             do_test (&json_ctx, i, 64, 256, seek, SMALL_CHAR, j);
> +             do_test (&json_ctx, i, 64, 256, seek, BIG_CHAR, j);
> +
> +             do_test (&json_ctx, i * 15, 64, 256, seek, SMALL_CHAR, j);
> +             do_test (&json_ctx, i * 15, 64, 256, seek, BIG_CHAR, j);
> +           }
> +
> +         for (i = 0; i < 32; ++i)
> +           {
> +             do_test (&json_ctx, 0, i, i + 1, seek, SMALL_CHAR, j);
> +             do_test (&json_ctx, 0, i, i + 1, seek, BIG_CHAR, j);
> +           }
> +         if (seek == 0)
> +           {
> +             break;
> +           }
> +       }
>      }
>
> -  for (i = 0; i < 32; ++i)
> -    {
> -      do_test (0, i, i + 1, 0, SMALL_CHAR);
> -      do_test (0, i, i + 1, 0, BIG_CHAR);
> -    }
> +  json_array_end (&json_ctx);
> +  json_attr_object_end (&json_ctx);
> +  json_attr_object_end (&json_ctx);
> +  json_document_end (&json_ctx);
>
>    return ret;
>  }
> --
> 2.25.1
>


-- 
H.J.