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TestIntrinsics.c
1#include <winpr/crt.h>
2#include <winpr/sysinfo.h>
3#include <winpr/windows.h>
4
5#include <winpr/intrin.h>
6
7static BOOL g_LZCNT = FALSE;
8
9static inline UINT32 lzcnt_s(UINT32 x)
10{
11 if (!x)
12 return 32;
13
14 if (!g_LZCNT)
15 {
16 UINT32 y = 0;
17 int n = 32;
18 y = x >> 16;
19 if (y != 0)
20 {
21 n = n - 16;
22 x = y;
23 }
24 y = x >> 8;
25 if (y != 0)
26 {
27 n = n - 8;
28 x = y;
29 }
30 y = x >> 4;
31 if (y != 0)
32 {
33 n = n - 4;
34 x = y;
35 }
36 y = x >> 2;
37 if (y != 0)
38 {
39 n = n - 2;
40 x = y;
41 }
42 y = x >> 1;
43 if (y != 0)
44 return n - 2;
45 return n - x;
46 }
47
48 return __lzcnt(x);
49}
50
51static int test_lzcnt(void)
52{
53 if (lzcnt_s(0x1) != 31)
54 {
55 (void)fprintf(stderr, "__lzcnt(0x1) != 31: %" PRIu32 "\n", __lzcnt(0x1));
56 return -1;
57 }
58
59 if (lzcnt_s(0xFF) != 24)
60 {
61 (void)fprintf(stderr, "__lzcnt(0xFF) != 24\n");
62 return -1;
63 }
64
65 if (lzcnt_s(0xFFFF) != 16)
66 {
67 (void)fprintf(stderr, "__lzcnt(0xFFFF) != 16\n");
68 return -1;
69 }
70
71 if (lzcnt_s(0xFFFFFF) != 8)
72 {
73 (void)fprintf(stderr, "__lzcnt(0xFFFFFF) != 8\n");
74 return -1;
75 }
76
77 if (lzcnt_s(0xFFFFFFFF) != 0)
78 {
79 (void)fprintf(stderr, "__lzcnt(0xFFFFFFFF) != 0\n");
80 return -1;
81 }
82
83 return 0;
84}
85
86static int test_lzcnt16(void)
87{
88 if (__lzcnt16(0x1) != 15)
89 {
90 (void)fprintf(stderr, "__lzcnt16(0x1) != 15\n");
91 return -1;
92 }
93
94 if (__lzcnt16(0xFF) != 8)
95 {
96 (void)fprintf(stderr, "__lzcnt16(0xFF) != 8\n");
97 return -1;
98 }
99
100 if (__lzcnt16(0xFFFF) != 0)
101 {
102 (void)fprintf(stderr, "__lzcnt16(0xFFFF) != 0\n");
103 return -1;
104 }
105
106 return 0;
107}
108
109int TestIntrinsics(int argc, char* argv[])
110{
111
112 WINPR_UNUSED(argc);
113 WINPR_UNUSED(argv);
114
115 g_LZCNT = IsProcessorFeaturePresentEx(PF_EX_LZCNT);
116
117 printf("LZCNT available: %" PRId32 "\n", g_LZCNT);
118
119 // test_lzcnt16();
120 return test_lzcnt();
121}