diff mbox series

[v7,1/2] benchtests: Add benchmark test for bsearch

Message ID 20240909162327.3163100-2-visitorckw@gmail.com
State New
Headers show
Series Optimization and benchmarking of bsearch() | expand

Commit Message

Kuan-Wei Chiu Sept. 9, 2024, 4:23 p.m. UTC
Introduce a benchmark test for the bsearch function to evaluate its
performance.

Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
---
Changes in v7:
- Drop 'nmemb' field and add 'element-size' field.

 benchtests/Makefile        |   1 +
 benchtests/bench-bsearch.c | 137 +++++++++++++++++++++++++++++++++++++
 2 files changed, 138 insertions(+)
 create mode 100644 benchtests/bench-bsearch.c

Comments

Noah Goldstein Sept. 9, 2024, 6:51 p.m. UTC | #1
On Mon, Sep 9, 2024 at 9:23 AM Kuan-Wei Chiu <visitorckw@gmail.com> wrote:
>
> Introduce a benchmark test for the bsearch function to evaluate its
> performance.
>
> Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
> ---
> Changes in v7:
> - Drop 'nmemb' field and add 'element-size' field.
>
>  benchtests/Makefile        |   1 +
>  benchtests/bench-bsearch.c | 137 +++++++++++++++++++++++++++++++++++++
>  2 files changed, 138 insertions(+)
>  create mode 100644 benchtests/bench-bsearch.c
>
> diff --git a/benchtests/Makefile b/benchtests/Makefile
> index d228e9e68a..955b766756 100644
> --- a/benchtests/Makefile
> +++ b/benchtests/Makefile
> @@ -253,6 +253,7 @@ hash-benchset := \
>
>  stdlib-benchset := \
>    arc4random \
> +  bsearch \
>    random-lock \
>    strtod \
>    # stdlib-benchset
> diff --git a/benchtests/bench-bsearch.c b/benchtests/bench-bsearch.c
> new file mode 100644
> index 0000000000..0dafd20fb5
> --- /dev/null
> +++ b/benchtests/bench-bsearch.c
> @@ -0,0 +1,137 @@
> +/* Measure bsearch functions.
> +   Copyright (C) 2022-2024 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
> +   <https://www.gnu.org/licenses/>.  */
> +
> +#define TEST_MAIN
> +#define TEST_NAME "bsearch"
> +
> +#define ARRAY_SIZE 100000
> +#define LOOP_ITERS 100000000
> +
> +/* Directly including <stdlib.h> leads to the use of an inline version
> +   of bsearch(), which may cause our test cases to be optimized away by
> +   the compiler due to predictability. To address this, we should
> +   include <bits/stdlib-bsearch.h> directly and replace __extern_inline
> +   with __attribute__((noinline)) to ensure the compiler does not
> +   inline the function. Additionally, we need to add some macros
> +   required for compilation. */
> +#include <stddef.h>
> +#define __extern_inline __attribute__((noinline))
> +#define __GNUC_PREREQ(x, y) 0
> +typedef int (*__compar_fn_t) (const void *, const void *);
> +#include <bits/stdlib-bsearch.h>
> +#undef __extern_inline
> +#undef __GNUC_PREREQ
> +
> +#include "json-lib.h"
> +#include "bench-timing.h"
> +
> +int arr[ARRAY_SIZE];
> +
> +static int
> +comp_asc (const void *p1, const void *p2)
> +{
> +  int x1 = *(int *) p1;
> +  int x2 = *(int *) p2;
> +
> +  if (x1 < x2)
> +    return -1;
> +  if (x1 > x2)
> +    return 1;
> +  return 0;
> +}
> +
> +static int
> +comp_desc (const void *p1, const void *p2)
> +{
> +  int x1 = *(int *) p1;
> +  int x2 = *(int *) p2;
> +
> +  if (x1 > x2)
> +    return -1;
> +  if (x1 < x2)
> +    return 1;
> +  return 0;
> +}
> +
> +static void
> +do_bench (json_ctx_t *json_ctx, bool ascending, bool contained)
> +{
> +  size_t i, iters = LOOP_ITERS;
> +  timing_t start, stop, cur;
> +  int key;
> +  volatile __attribute__((__unused__)) void *res;
> +
> +  for (i = 0; i < ARRAY_SIZE; ++i)
> +    {
> +      arr[i] = (ascending ? i : ARRAY_SIZE - 1 - i) << 1;
> +    }
> +
> +  json_element_object_begin (json_ctx);
> +  json_attr_uint (json_ctx, "array-size", ARRAY_SIZE);
> +  json_attr_uint (json_ctx, "element-size", sizeof(arr[0]));
> +  json_attr_string (json_ctx, "key-pattern", ascending ? "ascending" : "descending");
> +  json_attr_string (json_ctx, "contained", contained ? "yes" : "no");
> +  json_attr_string (json_ctx, "simple", "yes");
> +
> +  TIMING_NOW (start);
> +
> +  for (i = 0; i < iters; ++i)
> +    {
> +      key = (i % ARRAY_SIZE << 1) + !contained;
> +      res = bsearch(&key, arr, ARRAY_SIZE, sizeof(arr[0]), ascending ? comp_asc : comp_desc);
> +    }
> +
> +  TIMING_NOW (stop);
> +
> +  TIMING_DIFF (cur, start, stop);
> +
> +  json_attr_double (json_ctx, "timing", (double) cur / (double) iters);
> +  json_element_object_end (json_ctx);
> +}
> +
> +int
> +do_test (void)
> +{
> +  json_ctx_t json_ctx;
> +
> +  json_init (&json_ctx, 0, stdout);
> +
> +  json_document_begin (&json_ctx);
> +  json_attr_string (&json_ctx, "timing_type", TIMING_TYPE);
> +  json_attr_object_begin (&json_ctx, "functions");
> +  json_attr_object_begin (&json_ctx, TEST_NAME);
> +  json_attr_string (&json_ctx, "bench-variant", "default");
> +  json_array_begin (&json_ctx, "results");
> +
> +  for (int ascending = 0; ascending < 2; ++ascending)
> +    {
> +      for (int contained = 0; contained < 2; ++contained)
> +        {
> +          do_bench(&json_ctx, ascending, contained);
> +        }
> +    }
> +
> +  json_array_end (&json_ctx);
> +  json_attr_object_end (&json_ctx);
> +  json_attr_object_end (&json_ctx);
> +  json_document_end (&json_ctx);
> +
> +  return 0;
> +}
> +
> +#include <support/test-driver.c>
> --
> 2.34.1
>

LGTM
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
diff mbox series

Patch

diff --git a/benchtests/Makefile b/benchtests/Makefile
index d228e9e68a..955b766756 100644
--- a/benchtests/Makefile
+++ b/benchtests/Makefile
@@ -253,6 +253,7 @@  hash-benchset := \
 
 stdlib-benchset := \
   arc4random \
+  bsearch \
   random-lock \
   strtod \
   # stdlib-benchset
diff --git a/benchtests/bench-bsearch.c b/benchtests/bench-bsearch.c
new file mode 100644
index 0000000000..0dafd20fb5
--- /dev/null
+++ b/benchtests/bench-bsearch.c
@@ -0,0 +1,137 @@ 
+/* Measure bsearch functions.
+   Copyright (C) 2022-2024 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
+   <https://www.gnu.org/licenses/>.  */
+
+#define TEST_MAIN
+#define TEST_NAME "bsearch"
+
+#define ARRAY_SIZE 100000
+#define LOOP_ITERS 100000000
+
+/* Directly including <stdlib.h> leads to the use of an inline version
+   of bsearch(), which may cause our test cases to be optimized away by
+   the compiler due to predictability. To address this, we should
+   include <bits/stdlib-bsearch.h> directly and replace __extern_inline
+   with __attribute__((noinline)) to ensure the compiler does not
+   inline the function. Additionally, we need to add some macros
+   required for compilation. */
+#include <stddef.h>
+#define __extern_inline __attribute__((noinline))
+#define __GNUC_PREREQ(x, y) 0
+typedef int (*__compar_fn_t) (const void *, const void *);
+#include <bits/stdlib-bsearch.h>
+#undef __extern_inline
+#undef __GNUC_PREREQ
+
+#include "json-lib.h"
+#include "bench-timing.h"
+
+int arr[ARRAY_SIZE];
+
+static int
+comp_asc (const void *p1, const void *p2)
+{
+  int x1 = *(int *) p1;
+  int x2 = *(int *) p2;
+
+  if (x1 < x2)
+    return -1;
+  if (x1 > x2)
+    return 1;
+  return 0;
+}
+
+static int
+comp_desc (const void *p1, const void *p2)
+{
+  int x1 = *(int *) p1;
+  int x2 = *(int *) p2;
+
+  if (x1 > x2)
+    return -1;
+  if (x1 < x2)
+    return 1;
+  return 0;
+}
+
+static void
+do_bench (json_ctx_t *json_ctx, bool ascending, bool contained)
+{
+  size_t i, iters = LOOP_ITERS;
+  timing_t start, stop, cur;
+  int key;
+  volatile __attribute__((__unused__)) void *res;
+
+  for (i = 0; i < ARRAY_SIZE; ++i)
+    {
+      arr[i] = (ascending ? i : ARRAY_SIZE - 1 - i) << 1;
+    }
+
+  json_element_object_begin (json_ctx);
+  json_attr_uint (json_ctx, "array-size", ARRAY_SIZE);
+  json_attr_uint (json_ctx, "element-size", sizeof(arr[0]));
+  json_attr_string (json_ctx, "key-pattern", ascending ? "ascending" : "descending");
+  json_attr_string (json_ctx, "contained", contained ? "yes" : "no");
+  json_attr_string (json_ctx, "simple", "yes");
+
+  TIMING_NOW (start);
+
+  for (i = 0; i < iters; ++i)
+    {
+      key = (i % ARRAY_SIZE << 1) + !contained;
+      res = bsearch(&key, arr, ARRAY_SIZE, sizeof(arr[0]), ascending ? comp_asc : comp_desc);
+    }
+
+  TIMING_NOW (stop);
+
+  TIMING_DIFF (cur, start, stop);
+
+  json_attr_double (json_ctx, "timing", (double) cur / (double) iters);
+  json_element_object_end (json_ctx);
+}
+
+int
+do_test (void)
+{
+  json_ctx_t json_ctx;
+
+  json_init (&json_ctx, 0, stdout);
+
+  json_document_begin (&json_ctx);
+  json_attr_string (&json_ctx, "timing_type", TIMING_TYPE);
+  json_attr_object_begin (&json_ctx, "functions");
+  json_attr_object_begin (&json_ctx, TEST_NAME);
+  json_attr_string (&json_ctx, "bench-variant", "default");
+  json_array_begin (&json_ctx, "results");
+
+  for (int ascending = 0; ascending < 2; ++ascending)
+    {
+      for (int contained = 0; contained < 2; ++contained)
+        {
+          do_bench(&json_ctx, ascending, contained);
+        }
+    }
+
+  json_array_end (&json_ctx);
+  json_attr_object_end (&json_ctx);
+  json_attr_object_end (&json_ctx);
+  json_document_end (&json_ctx);
+
+  return 0;
+}
+
+#include <support/test-driver.c>