From 054da021d03e078c85b716f008c586cfaa86d686 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Steven=20Dee=20=28J=C5=8Dshin=29?= <git@wholezero.org>
Date: Wed, 26 Jun 2024 18:30:05 -0700
Subject: [PATCH] ctl::string benchmarking code (#1200)

---
 test/ctl/BUILD.mk        |   2 +
 test/ctl/string_bench.cc | 146 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 148 insertions(+)
 create mode 100644 test/ctl/string_bench.cc

diff --git a/test/ctl/BUILD.mk b/test/ctl/BUILD.mk
index 0a57a98cf..250e941d5 100644
--- a/test/ctl/BUILD.mk
+++ b/test/ctl/BUILD.mk
@@ -13,6 +13,8 @@ TEST_CTL_TESTS = $(TEST_CTL_COMS:%=%.ok)
 
 TEST_CTL_DIRECTDEPS =				\
 	CTL					\
+	LIBC_CALLS				\
+	LIBC_STDIO				\
 	LIBC_INTRIN				\
 	LIBC_MEM				\
 
diff --git a/test/ctl/string_bench.cc b/test/ctl/string_bench.cc
new file mode 100644
index 000000000..c59695dd1
--- /dev/null
+++ b/test/ctl/string_bench.cc
@@ -0,0 +1,146 @@
+// -*- mode:c++; indent-tabs-mode:nil; c-basic-offset:4; coding:utf-8 -*-
+// vi: set et ft=cpp ts=4 sts=4 sw=4 fenc=utf-8 :vi
+//
+// Copyright 2024 Justine Alexandra Roberts Tunney
+//
+// Permission to use, copy, modify, and/or distribute this software for
+// any purpose with or without fee is hereby granted, provided that the
+// above copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
+// WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
+// WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
+// AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
+// DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
+// PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+// TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+#include "ctl/string.h"
+
+#include <__utility/move.h>
+
+#include "libc/calls/struct/timespec.h"
+#include "libc/runtime/runtime.h"
+#include "libc/stdio/stdio.h"
+#include "libc/str/str.h"
+
+#define BENCH(ITERATIONS, WORK_PER_RUN, CODE) \
+    do { \
+        struct timespec start = timespec_real(); \
+        for (int __i = 0; __i < ITERATIONS; ++__i) { \
+            asm volatile("" ::: "memory"); \
+            CODE; \
+        } \
+        long long work = (WORK_PER_RUN) * (ITERATIONS); \
+        double nanos = \
+          (timespec_tonanos(timespec_sub(timespec_real(), start)) + work - \
+           1) / \
+          (double)work; \
+        printf("%10g ns %2dx %s\n", nanos, (ITERATIONS), #CODE); \
+    } while (0)
+
+const char* big_c = "aaaaaaaaaaaaaaaaaaaaaaaa";
+const char* small_c = "aaaaaaaaaaaaaaaaaaaaaaa";
+
+int
+main()
+{
+    const ctl::string_view big(big_c), small(small_c);
+
+    BENCH(10000000, 1, {
+        ctl::string s;
+        s.append("hello ");
+        s.append("world");
+    });
+
+    BENCH(1000000, 8, {
+        ctl::string s;
+        for (int i = 0; i < 8; ++i) {
+            s.append('a');
+        }
+    });
+
+    BENCH(1000000, 16, {
+        ctl::string s;
+        for (int i = 0; i < 16; ++i) {
+            s.append('a');
+        }
+    });
+
+    BENCH(1000000, 23, {
+        ctl::string s;
+        for (int i = 0; i < 23; ++i) {
+            s.append('a');
+        }
+    });
+
+    BENCH(1000000, 24, {
+        ctl::string s;
+        for (int i = 0; i < 24; ++i) {
+            s.append('a');
+        }
+    });
+
+    BENCH(1000000, 32, {
+        ctl::string s;
+        for (int i = 0; i < 32; ++i) {
+            s.append('a');
+        }
+    });
+
+    BENCH(1000000, 1, { ctl::string s(small_c); });
+
+    BENCH(1000000, 1, { ctl::string s(small); });
+
+    {
+        ctl::string small_copy("hello world");
+        BENCH(1000000, 1, { ctl::string s2(small_copy); });
+    }
+
+    BENCH(1000000, 1, {
+        ctl::string s(small);
+        ctl::string s2(std::move(s));
+    });
+
+    BENCH(1000000, 1, {
+        ctl::string s(small);
+        ctl::string s2(s);
+    });
+
+    BENCH(1000000, 1, { ctl::string s(big_c); });
+
+    BENCH(1000000, 1, { ctl::string s(big); });
+
+    {
+        ctl::string big_copy(big);
+        BENCH(1000000, 1, { ctl::string s2(big_copy); });
+    }
+
+    BENCH(1000000, 1, {
+        ctl::string s(big);
+        ctl::string s2(std::move(s));
+    });
+
+    BENCH(1000000, 1, {
+        ctl::string s(big);
+        ctl::string s2(s);
+    });
+
+    BENCH(1000000, 1, { ctl::string s(23, 'a'); });
+
+    BENCH(1000000, 1, { ctl::string s(24, 'a'); });
+
+    {
+        ctl::string s(5, 'a');
+        BENCH(1000000, 1, { ctl::string_view s2(s); });
+    }
+
+    {
+        ctl::string big_trunc(48, 'a');
+        big_trunc.resize(4);
+        BENCH(1000000, 1, { ctl::string s(big_trunc); });
+    }
+
+    return 0;
+}