1 /*
2  * Copyright © 2012 Intel Corporation
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining
5  * a copy of this software and associated documentation files (the
6  * "Software"), to deal in the Software without restriction, including
7  * without limitation the rights to use, copy, modify, merge, publish,
8  * distribute, sublicense, and/or sell copies of the Software, and to
9  * permit persons to whom the Software is furnished to do so, subject to
10  * the following conditions:
11  *
12  * The above copyright notice and this permission notice (including the
13  * next paragraph) shall be included in all copies or substantial
14  * portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
17  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
18  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
19  * NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
20  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
21  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
22  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
23  * SOFTWARE.
24  */
25 
26 #include <stdlib.h>
27 #include <stdio.h>
28 #include <string.h>
29 #include <time.h>
30 #include <assert.h>
31 #include "wayland-private.h"
32 
33 volatile double global_d;
34 
35 static void
36 noop_conversion(void)
37 {
38 	wl_fixed_t f;
39 	union {
40 		int64_t i;
41 		double d;
42 	} u;
43 
44 	for (f = 0; f < INT32_MAX; f++) {
45 		u.i = f;
46 		global_d = u.d;
47 	}
48 }
49 
50 static void
51 magic_conversion(void)
52 {
53 	wl_fixed_t f;
54 
55 	for (f = 0; f < INT32_MAX; f++)
56 		global_d = wl_fixed_to_double(f);
57 }
58 
59 static void
60 mul_conversion(void)
61 {
62 	wl_fixed_t f;
63 
64 	/* This will get optimized into multiplication by 1/256 */
65 	for (f = 0; f < INT32_MAX; f++)
66 		global_d = f / 256.0;
67 }
68 
69 double factor = 256.0;
70 
71 static void
72 div_conversion(void)
73 {
74 	wl_fixed_t f;
75 
76 	for (f = 0; f < INT32_MAX; f++)
77 		global_d = f / factor;
78 }
79 
80 static void
81 benchmark(const char *s, void (*f)(void))
82 {
83 	struct timespec start, stop, elapsed;
84 
85 	clock_gettime(CLOCK_MONOTONIC, &start);
86 	f();
87 	clock_gettime(CLOCK_MONOTONIC, &stop);
88 
89 	elapsed.tv_sec = stop.tv_sec - start.tv_sec;
90 	elapsed.tv_nsec = stop.tv_nsec - start.tv_nsec;
91 	if (elapsed.tv_nsec < 0) {
92 		elapsed.tv_nsec += 1000000000;
93 		elapsed.tv_sec--;
94 	}
95 	printf("benchmarked %s:\t%ld.%09lds\n",
96 	       s, elapsed.tv_sec, elapsed.tv_nsec);
97 }
98 
99 int main(void)
100 {
101 	benchmark("noop", noop_conversion);
102 	benchmark("magic", magic_conversion);
103 	benchmark("div", div_conversion);
104 	benchmark("mul", mul_conversion);
105 
106 	return 0;
107 }
108