From b1b97e8d348ed3ac9c9c422534bd47bc8fb2d31e Mon Sep 17 00:00:00 2001 From: Manuel Stoeckl Date: Sat, 25 Feb 2023 15:57:47 -0500 Subject: tests: drop misleading fixed-benchmark Because this benchmark performed wl_fixed_to_double conversions on a long sequence of consecutive integers, the compiler could optimize away the addition performed in wl_fixed_to_double, merging it with the loop iteration code. This made tests/fixed-benchmark.c significantly underestimate the actual cost of the current wl_fixed_to_double implementation. Signed-off-by: Manuel Stoeckl --- tests/fixed-benchmark.c | 107 ------------------------------------------------ tests/meson.build | 9 ---- 2 files changed, 116 deletions(-) delete mode 100644 tests/fixed-benchmark.c diff --git a/tests/fixed-benchmark.c b/tests/fixed-benchmark.c deleted file mode 100644 index 277ecce..0000000 --- a/tests/fixed-benchmark.c +++ /dev/null @@ -1,107 +0,0 @@ -/* - * Copyright © 2012 Intel Corporation - * - * Permission is hereby granted, free of charge, to any person obtaining - * a copy of this software and associated documentation files (the - * "Software"), to deal in the Software without restriction, including - * without limitation the rights to use, copy, modify, merge, publish, - * distribute, sublicense, and/or sell copies of the Software, and to - * permit persons to whom the Software is furnished to do so, subject to - * the following conditions: - * - * The above copyright notice and this permission notice (including the - * next paragraph) shall be included in all copies or substantial - * portions of the Software. - * - * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, - * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF - * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND - * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS - * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN - * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN - * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE - * SOFTWARE. - */ - -#include -#include -#include -#include -#include -#include "wayland-private.h" - -volatile double global_d; - -static void -noop_conversion(void) -{ - wl_fixed_t f; - union { - int64_t i; - double d; - } u; - - for (f = 0; f < INT32_MAX; f++) { - u.i = f; - global_d = u.d; - } -} - -static void -magic_conversion(void) -{ - wl_fixed_t f; - - for (f = 0; f < INT32_MAX; f++) - global_d = wl_fixed_to_double(f); -} - -static void -mul_conversion(void) -{ - wl_fixed_t f; - - /* This will get optimized into multiplication by 1/256 */ - for (f = 0; f < INT32_MAX; f++) - global_d = f / 256.0; -} - -double factor = 256.0; - -static void -div_conversion(void) -{ - wl_fixed_t f; - - for (f = 0; f < INT32_MAX; f++) - global_d = f / factor; -} - -static void -benchmark(const char *s, void (*f)(void)) -{ - struct timespec start, stop, elapsed; - - clock_gettime(CLOCK_MONOTONIC, &start); - f(); - clock_gettime(CLOCK_MONOTONIC, &stop); - - elapsed.tv_sec = stop.tv_sec - start.tv_sec; - elapsed.tv_nsec = stop.tv_nsec - start.tv_nsec; - if (elapsed.tv_nsec < 0) { - elapsed.tv_nsec += 1000000000; - elapsed.tv_sec--; - } - printf("benchmarked %s:\t%ld.%09lds\n", - s, elapsed.tv_sec, elapsed.tv_nsec); -} - -int main(void) -{ - benchmark("noop", noop_conversion); - benchmark("magic", magic_conversion); - benchmark("div", div_conversion); - benchmark("mul", mul_conversion); - - return 0; -} diff --git a/tests/meson.build b/tests/meson.build index 5efd6f7..40e3ab3 100644 --- a/tests/meson.build +++ b/tests/meson.build @@ -54,15 +54,6 @@ tests_protocol_c = custom_target( output: 'tests-protocol.c' ) -benchmark( - 'fixed-benchmark', - executable( - 'fixed-benchmark', - 'fixed-benchmark.c', - dependencies: [ test_runner_dep, rt_dep ] - ) -) - executable( 'exec-fd-leak-checker', 'exec-fd-leak-checker.c', -- cgit v1.2.1