From a06d9eddb015a9f5895161b0a3958a2e4be21579 Mon Sep 17 00:00:00 2001
From: Richard Henderson <richard.henderson@linaro.org>
Date: Fri, 16 Feb 2024 13:59:36 -1000
Subject: [PATCH] tests/bench: Add bufferiszero-bench
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Benchmark each acceleration function vs an aligned buffer of zeros.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 tests/bench/bufferiszero-bench.c | 47 ++++++++++++++++++++++++++++++++
 tests/bench/meson.build          |  1 +
 2 files changed, 48 insertions(+)
 create mode 100644 tests/bench/bufferiszero-bench.c

diff --git a/tests/bench/bufferiszero-bench.c b/tests/bench/bufferiszero-bench.c
new file mode 100644
index 0000000000..222695c1fa
--- /dev/null
+++ b/tests/bench/bufferiszero-bench.c
@@ -0,0 +1,47 @@
+/*
+ * QEMU buffer_is_zero speed benchmark
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or
+ * (at your option) any later version.  See the COPYING file in the
+ * top-level directory.
+ */
+#include "qemu/osdep.h"
+#include "qemu/cutils.h"
+#include "qemu/units.h"
+
+static void test(const void *opaque)
+{
+    size_t max = 64 * KiB;
+    void *buf = g_malloc0(max);
+    int accel_index = 0;
+
+    do {
+        if (accel_index != 0) {
+            g_test_message("%s", "");  /* gnu_printf Werror for simple "" */
+        }
+        for (size_t len = 1 * KiB; len <= max; len *= 4) {
+            double total = 0.0;
+
+            g_test_timer_start();
+            do {
+                buffer_is_zero_ge256(buf, len);
+                total += len;
+            } while (g_test_timer_elapsed() < 0.5);
+
+            total /= MiB;
+            g_test_message("buffer_is_zero #%d: %2zuKB %8.0f MB/sec",
+                           accel_index, len / (size_t)KiB,
+                           total / g_test_timer_last());
+        }
+        accel_index++;
+    } while (test_buffer_is_zero_next_accel());
+
+    g_free(buf);
+}
+
+int main(int argc, char **argv)
+{
+    g_test_init(&argc, &argv, NULL);
+    g_test_add_data_func("/cutils/bufferiszero/speed", NULL, test);
+    return g_test_run();
+}
diff --git a/tests/bench/meson.build b/tests/bench/meson.build
index 7e76338a52..4cd7a2f6b5 100644
--- a/tests/bench/meson.build
+++ b/tests/bench/meson.build
@@ -21,6 +21,7 @@ benchs = {}
 
 if have_block
   benchs += {
+     'bufferiszero-bench': [],
      'benchmark-crypto-hash': [crypto],
      'benchmark-crypto-hmac': [crypto],
      'benchmark-crypto-cipher': [crypto],