[v2] benchtests: Add benches for bzero

diff --git a/benchtests/Makefile b/benchtests/Makefile
index 7c330e9967..6f718fac35 100644
--- a/benchtests/Makefile
+++ b/benchtests/Makefile
@@ -119,6 +119,9 @@  endif
 
 # String function benchmarks.
 string-benchset := \
+  bzero \
+  bzero-large \
+  bzero-walk \
   memccpy \
   memchr \
   memcmp \
diff --git a/benchtests/bench-bzero-large.c b/benchtests/bench-bzero-large.c
new file mode 100644
index 0000000000..f2e2e981b7
--- /dev/null
+++ b/benchtests/bench-bzero-large.c
@@ -0,0 +1,117 @@ 
+/* Measure bzero functions with large data sizes.
+   Copyright (C) 2022 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 "bzero"
+#define START_SIZE (128 * 1024)
+#define MIN_PAGE_SIZE (getpagesize () + 64 * 1024 * 1024)
+#define TIMEOUT (20 * 60)
+#include "bench-string.h"
+
+#include "json-lib.h"
+
+static void
+memset_zero (void * s, size_t len)
+{
+  memset (s, '\0', len);
+}
+
+typedef void (*proto_t) (void *, size_t);
+
+IMPL (bzero, 1)
+IMPL (memset_zero, 0)
+
+static void
+do_one_test (json_ctx_t *json_ctx, impl_t *impl, CHAR *s, size_t n)
+{
+  size_t i, iters = 16;
+  timing_t start, stop, cur;
+
+  TIMING_NOW (start);
+  for (i = 0; i < iters; ++i)
+    {
+      CALL (impl, s, n);
+    }
+  TIMING_NOW (stop);
+
+  TIMING_DIFF (cur, start, stop);
+
+  json_element_double (json_ctx, (double) cur / (double) iters);
+}
+
+static void
+do_test (json_ctx_t *json_ctx, size_t align, size_t len)
+{
+  align &= 63;
+  if ((align + len) * sizeof (CHAR) > page_size)
+    return;
+
+  json_element_object_begin (json_ctx);
+  json_attr_uint (json_ctx, "length", len);
+  json_attr_uint (json_ctx, "alignment", align);
+  json_array_begin (json_ctx, "timings");
+
+  FOR_EACH_IMPL (impl, 0)
+    {
+      do_one_test (json_ctx, impl, (CHAR *) (buf1) + align, len);
+      alloc_bufs ();
+    }
+
+  json_array_end (json_ctx);
+  json_element_object_end (json_ctx);
+}
+
+int
+test_main (void)
+{
+  json_ctx_t json_ctx;
+  size_t i;
+
+  test_init ();
+
+  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", "large");
+
+  json_array_begin (&json_ctx, "ifuncs");
+  FOR_EACH_IMPL (impl, 0)
+    json_element_string (&json_ctx, impl->name);
+  json_array_end (&json_ctx);
+
+  json_array_begin (&json_ctx, "results");
+
+  for (i = START_SIZE; i <= MIN_PAGE_SIZE; i <<= 1)
+    {
+      do_test (&json_ctx, 0, i);
+      do_test (&json_ctx, 3, i);
+    }
+
+  json_array_end (&json_ctx);
+  json_attr_object_end (&json_ctx);
+  json_attr_object_end (&json_ctx);
+  json_document_end (&json_ctx);
+
+  return ret;
+}
+
+#include <support/test-driver.c>
diff --git a/benchtests/bench-bzero-walk.c b/benchtests/bench-bzero-walk.c
new file mode 100644
index 0000000000..b65d12a6a2
--- /dev/null
+++ b/benchtests/bench-bzero-walk.c
@@ -0,0 +1,118 @@ 
+/* Measure memset function throughput with large data sizes.
+   Copyright (C) 2017-2022 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 "bzero"
+#define START_SIZE 128
+#define MIN_PAGE_SIZE (getpagesize () + 32 * 1024 * 1024)
+#define TIMEOUT (20 * 60)
+#include "bench-string.h"
+
+#include "json-lib.h"
+
+static void
+memset_zero (void * s, size_t len)
+{
+  memset (s, '\0', len);
+}
+
+typedef void (*proto_t) (void *, size_t);
+
+IMPL (bzero, 1)
+IMPL (memset_zero, 0)
+
+static void
+do_one_test (json_ctx_t *json_ctx, impl_t *impl, CHAR *s, CHAR *s_end,
+	     size_t n)
+{
+  size_t i, iters = MIN_PAGE_SIZE / n;
+  timing_t start, stop, cur;
+
+  TIMING_NOW (start);
+  for (i = 0; i < iters && s <= s_end; s_end -= n, i++)
+    CALL (impl, s, n);
+  TIMING_NOW (stop);
+
+  TIMING_DIFF (cur, start, stop);
+
+  /* Get time taken per function call.  */
+  json_element_double (json_ctx, (double) cur / i);
+}
+
+static void
+do_test (json_ctx_t *json_ctx, size_t len)
+{
+  json_element_object_begin (json_ctx);
+  json_attr_uint (json_ctx, "length", len);
+  json_array_begin (json_ctx, "timings");
+
+  FOR_EACH_IMPL (impl, 0)
+    {
+      do_one_test (json_ctx, impl, (CHAR *) buf1,
+		   (CHAR *) buf1 + MIN_PAGE_SIZE - len, len);
+      alloc_bufs ();
+    }
+
+  json_array_end (json_ctx);
+  json_element_object_end (json_ctx);
+}
+
+int
+test_main (void)
+{
+  json_ctx_t json_ctx;
+  size_t i;
+
+  test_init ();
+
+  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", "walk");
+
+  json_array_begin (&json_ctx, "ifuncs");
+  FOR_EACH_IMPL (impl, 0)
+    json_element_string (&json_ctx, impl->name);
+  json_array_end (&json_ctx);
+
+  json_array_begin (&json_ctx, "results");
+  for (i = START_SIZE; i <= MIN_PAGE_SIZE; i <<= 1)
+    {
+      do_test (&json_ctx, i);
+      do_test (&json_ctx, i + 1);
+    }
+
+  for (i = START_SIZE; i <= MIN_PAGE_SIZE; i <<= 1)
+    {
+      do_test (&json_ctx, i);
+      do_test (&json_ctx, i + 1);
+    }
+
+  json_array_end (&json_ctx);
+  json_attr_object_end (&json_ctx);
+  json_attr_object_end (&json_ctx);
+  json_document_end (&json_ctx);
+
+  return ret;
+}
+
+#include <support/test-driver.c>
diff --git a/benchtests/bench-bzero.c b/benchtests/bench-bzero.c
new file mode 100644
index 0000000000..93ec521725
--- /dev/null
+++ b/benchtests/bench-bzero.c
@@ -0,0 +1,134 @@ 
+/* Measure bzero functions.
+   Copyright (C) 2022 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 "bzero"
+#define MIN_PAGE_SIZE 131072
+#include "bench-string.h"
+
+#include "json-lib.h"
+
+static void
+memset_zero (void * s, size_t len)
+{
+  memset (s, '\0', len);
+}
+
+typedef void (*proto_t) (void *, size_t);
+
+IMPL (bzero, 1)
+IMPL (memset_zero, 0)
+
+static void
+do_one_test (json_ctx_t *json_ctx, impl_t *impl, CHAR *s, size_t n)
+{
+  size_t i, iters = INNER_LOOP_ITERS_LARGE;
+  timing_t start, stop, cur;
+
+  TIMING_NOW (start);
+  for (i = 0; i < iters; ++i)
+    {
+      CALL (impl, s, n);
+    }
+  TIMING_NOW (stop);
+
+  TIMING_DIFF (cur, start, stop);
+
+  json_element_double (json_ctx, (double) cur / (double) iters);
+}
+
+static void
+do_test (json_ctx_t *json_ctx, size_t align, size_t len)
+{
+  align &= 4095;
+  if ((align + len) * sizeof (CHAR) > page_size)
+    return;
+
+  json_element_object_begin (json_ctx);
+  json_attr_uint (json_ctx, "length", len);
+  json_attr_uint (json_ctx, "alignment", align);
+  json_array_begin (json_ctx, "timings");
+
+  FOR_EACH_IMPL (impl, 0)
+    {
+      do_one_test (json_ctx, impl, (CHAR *) (buf1) + align, len);
+    }
+
+  json_array_end (json_ctx);
+  json_element_object_end (json_ctx);
+}
+
+int
+test_main (void)
+{
+  json_ctx_t json_ctx;
+  size_t i;
+
+  test_init ();
+  alloc_bufs ();
+  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, "ifuncs");
+  FOR_EACH_IMPL (impl, 0)
+    json_element_string (&json_ctx, impl->name);
+  json_array_end (&json_ctx);
+
+  json_array_begin (&json_ctx, "results");
+
+  for (i = 0; i < 18; ++i)
+    do_test (&json_ctx, 0, 1 << i);
+  for (i = 0; i < 64; ++i)
+    {
+      do_test (&json_ctx, i, i);
+      do_test (&json_ctx, 4096 - i, i);
+      do_test (&json_ctx, 4095, i);
+      if (i & (i - 1))
+	do_test (&json_ctx, 0, i);
+    }
+  for (i = 32; i < 1024; i+=32)
+    {
+      do_test (&json_ctx, 0, i);
+      do_test (&json_ctx, i, i);
+    }
+  do_test (&json_ctx, 1, 14);
+  do_test (&json_ctx, 3, 1024);
+  do_test (&json_ctx, 4, 64);
+  do_test (&json_ctx, 2, 25);
+
+  for (i = 33; i <= 256; i += 4)
+    {
+      do_test (&json_ctx, 0, 32 * i);
+      do_test (&json_ctx, i, 32 * i);
+    }
+
+  json_array_end (&json_ctx);
+  json_attr_object_end (&json_ctx);
+  json_attr_object_end (&json_ctx);
+  json_document_end (&json_ctx);
+
+  return ret;
+}
+
+#include <support/test-driver.c>