1 /*	$OpenBSD: reg.c,v 1.3 2016/08/14 23:01:13 guenther Exp $	*/
2 
3 /*
4  * Copyright (c) 2003 Jason L. Wright (jason@thought.net)
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
20  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
22  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
24  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
25  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  * POSSIBILITY OF SUCH DAMAGE.
27  */
28 #include <sys/types.h>
29 #include <stdio.h>
30 
31 int64_t asm_popc(int64_t);
32 int64_t c_popc(int64_t);
33 int test_it(int64_t);
34 int test_ones(void);
35 int main(void);
36 
37 int64_t
38 asm_popc(int64_t v)
39 {
40 	asm("popc %1, %0" : "=r" (v) : "r" (v));
41 	return (v);
42 }
43 
44 int64_t
45 c_popc(int64_t v)
46 {
47 	int64_t bit, r;
48 
49 	for (bit = 1, r = 0; bit; bit <<= 1)
50 		if (v & bit)
51 			r++;
52 	return (r);
53 }
54 
55 int
56 test_it(int64_t v)
57 {
58 	int64_t tc, ta;
59 
60 	tc = c_popc(v);
61 	ta = asm_popc(v);
62 	if (tc == ta)
63 		return (0);
64 	printf("%lld: C(%lld) ASM(%lld)\n", v, tc, ta);
65 	return (1);
66 }
67 
68 int
69 test_ones(void)
70 {
71 	int64_t v;
72 	int i, r = 0;
73 
74 	for (i = 0; i < 64; i++) {
75 		v = 1LL << i;
76 		if (c_popc(v) != 1) {
77 			printf("ONES popc(%lld) != 1\n", v);
78 			r = 1;
79 		}
80 		if (test_it(v))
81 			r = 1;
82 	}
83 	return (r);
84 }
85 
86 int
87 main()
88 {
89 	int r = 0;
90 
91 	if (test_ones())
92 		r = 1;
93 
94 	return (r);
95 }
96