diff --git a/benchtests/Makefile b/benchtests/Makefile
index 5a07d1f91d..cccee62eb0 100644
--- a/benchtests/Makefile
+++ b/benchtests/Makefile
@@ -201,6 +201,7 @@ string-benchset := \
strcpy_chk \
strcspn \
strlen \
+ strlen-random \
strncasecmp \
strncat \
strncmp \
diff --git a/benchtests/bench-strlen-random.c b/benchtests/bench-strlen-random.c
new file mode 100644
index 0000000000..becd09a2ca
--- /dev/null
+++ b/benchtests/bench-strlen-random.c
@@ -0,0 +1,194 @@
+/* Measure strlen performance.
+ Copyright (C) 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
+ . */
+
+#define TEST_MAIN
+#define TEST_NAME "strlen"
+
+#define NUM_TESTS 65536
+#define MAX_ALIGN 32
+#define MAX_STRLEN 128
+#define MIN_PAGE_SIZE (2 * getpagesize())
+
+#include "bench-string.h"
+#include
+#include "json-lib.h"
+
+typedef size_t (*proto_t) (const CHAR *);
+
+size_t memchr_strlen (const CHAR *);
+
+IMPL (memchr_strlen, 0)
+
+size_t
+memchr_strlen (const CHAR *p)
+{
+ return (const CHAR *)MEMCHR (p, 0, PTRDIFF_MAX) - p;
+}
+
+IMPL (STRLEN, 1)
+
+static uint32_t strlen_tests[NUM_TESTS];
+
+typedef struct { uint16_t size; uint16_t freq; } freq_data_t;
+typedef struct { uint16_t align; uint16_t freq; } align_data_t;
+
+#define SIZE_NUM 65536
+#define SIZE_MASK (SIZE_NUM-1)
+static uint8_t strlen_len_arr[SIZE_NUM];
+
+/* Frequency data for strlen sizes up to 256 based on SPEC2017. */
+static freq_data_t strlen_len_freq[] =
+{
+ { 12,22671}, { 18,12834}, { 13, 9555}, { 6, 6348}, { 17, 6095}, { 11, 2115},
+ { 10, 1335}, { 7, 814}, { 2, 646}, { 9, 483}, { 8, 471}, { 16, 418},
+ { 4, 390}, { 1, 388}, { 5, 233}, { 3, 204}, { 0, 79}, { 14, 79},
+ { 15, 69}, { 26, 36}, { 22, 35}, { 31, 24}, { 32, 24}, { 19, 21},
+ { 25, 17}, { 28, 15}, { 21, 14}, { 33, 14}, { 20, 13}, { 24, 9},
+ { 29, 9}, { 30, 9}, { 23, 7}, { 34, 7}, { 27, 6}, { 44, 5},
+ { 42, 4}, { 45, 3}, { 47, 3}, { 40, 2}, { 41, 2}, { 43, 2},
+ { 58, 2}, { 78, 2}, { 36, 2}, { 48, 1}, { 52, 1}, { 60, 1},
+ { 64, 1}, { 56, 1}, { 76, 1}, { 68, 1}, { 80, 1}, { 84, 1},
+ { 72, 1}, { 86, 1}, { 35, 1}, { 39, 1}, { 50, 1}, { 38, 1},
+ { 37, 1}, { 46, 1}, { 98, 1}, {102, 1}, {128, 1}, { 51, 1},
+ {107, 1}, { 0, 0}
+};
+
+#define ALIGN_NUM 1024
+#define ALIGN_MASK (ALIGN_NUM-1)
+static uint8_t strlen_align_arr[ALIGN_NUM];
+
+/* Alignment data for strlen based on SPEC2017. */
+static align_data_t string_align_freq[] =
+{
+ {8, 470}, {32, 427}, {16, 99}, {1, 19}, {2, 6}, {4, 3}, {0, 0}
+};
+
+static void
+init_strlen_distribution (void)
+{
+ int i, j, freq, size, n;
+
+ for (n = i = 0; (freq = strlen_len_freq[i].freq) != 0; i++)
+ for (j = 0, size = strlen_len_freq[i].size; j < freq; j++)
+ strlen_len_arr[n++] = size;
+ assert (n == SIZE_NUM);
+
+ for (n = i = 0; (freq = string_align_freq[i].freq) != 0; i++)
+ for (j = 0, size = string_align_freq[i].align; j < freq; j++)
+ strlen_align_arr[n++] = size;
+ assert (n == ALIGN_NUM);
+}
+
+static volatile size_t maskv = 0;
+
+static void
+do_one_test (json_ctx_t *json_ctx, impl_t *impl, size_t iters,
+ uint32_t *input, size_t n)
+{
+ timing_t start, stop, cur;
+ size_t res = 0;
+ size_t mask = maskv;
+
+ /* Avoid 'cold start' performance penalty. */
+ for (int i = 0; i < 10; i++)
+ for (int j = 0; j < n; j++)
+ CALL (impl, (const char*)buf1 + input[j]);
+
+ TIMING_NOW (start);
+ for (int i = 0; i < iters; ++i)
+ for (int j = 0; j < n; j++)
+ res = CALL (impl, (const char*)buf1 + input[j] + (res & mask));
+ 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 n;
+ uint8_t *a = buf1;
+ uint16_t index[MAX_ALIGN];
+
+ memset (a, 'x', MIN_PAGE_SIZE);
+
+ /* Create indices for strings at all alignments. */
+ for (int i = 0; i < MAX_ALIGN; i++)
+ {
+ index[i] = i * (MAX_STRLEN + 1);
+ a[index[i] + MAX_STRLEN] = 0;
+ }
+
+ /* Create a random set of strlen input strings using the string length
+ and alignment distributions. */
+ for (n = 0; n < NUM_TESTS; n++)
+ {
+ int align = strlen_align_arr[rand () & ALIGN_MASK];
+ int exp_len = strlen_len_arr[rand () & SIZE_MASK];
+
+ strlen_tests[n] =
+ index[(align + exp_len) & (MAX_ALIGN - 1)] + MAX_STRLEN - exp_len;
+ assert ((strlen_tests[n] & (align - 1)) == 0);
+ assert (strlen ((char*) a + strlen_tests[n]) == exp_len);
+ }
+
+ json_element_object_begin (json_ctx);
+ json_array_begin (json_ctx, "timings");
+
+ FOR_EACH_IMPL (impl, 0)
+ do_one_test (json_ctx, impl, INNER_LOOP_ITERS_MEDIUM, strlen_tests, n);
+
+ json_array_end (json_ctx);
+ json_element_object_end (json_ctx);
+}
+
+int
+test_main (void)
+{
+
+ json_ctx_t json_ctx;
+
+ test_init ();
+ init_strlen_distribution ();
+
+ 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", "random");
+
+ 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");
+ do_test (&json_ctx);
+
+ 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