xref: /netbsd-src/external/bsd/jemalloc/dist/test/unit/prng.c (revision 4439cfd0acf9c7dc90625e5cd83b2317a9ab8967)
1 #include "test/jemalloc_test.h"
2 
3 TEST_BEGIN(test_prng_lg_range_u32) {
4 	uint32_t sa, sb;
5 	uint32_t ra, rb;
6 	unsigned lg_range;
7 
8 	sa = 42;
9 	ra = prng_lg_range_u32(&sa, 32);
10 	sa = 42;
11 	rb = prng_lg_range_u32(&sa, 32);
12 	expect_u32_eq(ra, rb,
13 	    "Repeated generation should produce repeated results");
14 
15 	sb = 42;
16 	rb = prng_lg_range_u32(&sb, 32);
17 	expect_u32_eq(ra, rb,
18 	    "Equivalent generation should produce equivalent results");
19 
20 	sa = 42;
21 	ra = prng_lg_range_u32(&sa, 32);
22 	rb = prng_lg_range_u32(&sa, 32);
23 	expect_u32_ne(ra, rb,
24 	    "Full-width results must not immediately repeat");
25 
26 	sa = 42;
27 	ra = prng_lg_range_u32(&sa, 32);
28 	for (lg_range = 31; lg_range > 0; lg_range--) {
29 		sb = 42;
30 		rb = prng_lg_range_u32(&sb, lg_range);
31 		expect_u32_eq((rb & (UINT32_C(0xffffffff) << lg_range)),
32 		    0, "High order bits should be 0, lg_range=%u", lg_range);
33 		expect_u32_eq(rb, (ra >> (32 - lg_range)),
34 		    "Expected high order bits of full-width result, "
35 		    "lg_range=%u", lg_range);
36 	}
37 
38 }
39 TEST_END
40 
41 TEST_BEGIN(test_prng_lg_range_u64) {
42 	uint64_t sa, sb, ra, rb;
43 	unsigned lg_range;
44 
45 	sa = 42;
46 	ra = prng_lg_range_u64(&sa, 64);
47 	sa = 42;
48 	rb = prng_lg_range_u64(&sa, 64);
49 	expect_u64_eq(ra, rb,
50 	    "Repeated generation should produce repeated results");
51 
52 	sb = 42;
53 	rb = prng_lg_range_u64(&sb, 64);
54 	expect_u64_eq(ra, rb,
55 	    "Equivalent generation should produce equivalent results");
56 
57 	sa = 42;
58 	ra = prng_lg_range_u64(&sa, 64);
59 	rb = prng_lg_range_u64(&sa, 64);
60 	expect_u64_ne(ra, rb,
61 	    "Full-width results must not immediately repeat");
62 
63 	sa = 42;
64 	ra = prng_lg_range_u64(&sa, 64);
65 	for (lg_range = 63; lg_range > 0; lg_range--) {
66 		sb = 42;
67 		rb = prng_lg_range_u64(&sb, lg_range);
68 		expect_u64_eq((rb & (UINT64_C(0xffffffffffffffff) << lg_range)),
69 		    0, "High order bits should be 0, lg_range=%u", lg_range);
70 		expect_u64_eq(rb, (ra >> (64 - lg_range)),
71 		    "Expected high order bits of full-width result, "
72 		    "lg_range=%u", lg_range);
73 	}
74 }
75 TEST_END
76 
77 TEST_BEGIN(test_prng_lg_range_zu) {
78 	size_t sa, sb;
79 	size_t ra, rb;
80 	unsigned lg_range;
81 
82 	sa = 42;
83 	ra = prng_lg_range_zu(&sa, ZU(1) << (3 + LG_SIZEOF_PTR));
84 	sa = 42;
85 	rb = prng_lg_range_zu(&sa, ZU(1) << (3 + LG_SIZEOF_PTR));
86 	expect_zu_eq(ra, rb,
87 	    "Repeated generation should produce repeated results");
88 
89 	sb = 42;
90 	rb = prng_lg_range_zu(&sb, ZU(1) << (3 + LG_SIZEOF_PTR));
91 	expect_zu_eq(ra, rb,
92 	    "Equivalent generation should produce equivalent results");
93 
94 	sa = 42;
95 	ra = prng_lg_range_zu(&sa, ZU(1) << (3 + LG_SIZEOF_PTR));
96 	rb = prng_lg_range_zu(&sa, ZU(1) << (3 + LG_SIZEOF_PTR));
97 	expect_zu_ne(ra, rb,
98 	    "Full-width results must not immediately repeat");
99 
100 	sa = 42;
101 	ra = prng_lg_range_zu(&sa, ZU(1) << (3 + LG_SIZEOF_PTR));
102 	for (lg_range = (ZU(1) << (3 + LG_SIZEOF_PTR)) - 1; lg_range > 0;
103 	    lg_range--) {
104 		sb = 42;
105 		rb = prng_lg_range_zu(&sb, lg_range);
106 		expect_zu_eq((rb & (SIZE_T_MAX << lg_range)),
107 		    0, "High order bits should be 0, lg_range=%u", lg_range);
108 		expect_zu_eq(rb, (ra >> ((ZU(1) << (3 + LG_SIZEOF_PTR)) -
109 		    lg_range)), "Expected high order bits of full-width "
110 		    "result, lg_range=%u", lg_range);
111 	}
112 
113 }
114 TEST_END
115 
116 TEST_BEGIN(test_prng_range_u32) {
117 	uint32_t range;
118 
119 	const uint32_t max_range = 10000000;
120 	const uint32_t range_step = 97;
121 	const unsigned nreps = 10;
122 
123 	for (range = 2; range < max_range; range += range_step) {
124 		uint32_t s;
125 		unsigned rep;
126 
127 		s = range;
128 		for (rep = 0; rep < nreps; rep++) {
129 			uint32_t r = prng_range_u32(&s, range);
130 
131 			expect_u32_lt(r, range, "Out of range");
132 		}
133 	}
134 }
135 TEST_END
136 
137 TEST_BEGIN(test_prng_range_u64) {
138 	uint64_t range;
139 
140 	const uint64_t max_range = 10000000;
141 	const uint64_t range_step = 97;
142 	const unsigned nreps = 10;
143 
144 	for (range = 2; range < max_range; range += range_step) {
145 		uint64_t s;
146 		unsigned rep;
147 
148 		s = range;
149 		for (rep = 0; rep < nreps; rep++) {
150 			uint64_t r = prng_range_u64(&s, range);
151 
152 			expect_u64_lt(r, range, "Out of range");
153 		}
154 	}
155 }
156 TEST_END
157 
158 TEST_BEGIN(test_prng_range_zu) {
159 	size_t range;
160 
161 	const size_t max_range = 10000000;
162 	const size_t range_step = 97;
163 	const unsigned nreps = 10;
164 
165 
166 	for (range = 2; range < max_range; range += range_step) {
167 		size_t s;
168 		unsigned rep;
169 
170 		s = range;
171 		for (rep = 0; rep < nreps; rep++) {
172 			size_t r = prng_range_zu(&s, range);
173 
174 			expect_zu_lt(r, range, "Out of range");
175 		}
176 	}
177 }
178 TEST_END
179 
180 int
181 main(void) {
182 	return test_no_reentrancy(
183 	    test_prng_lg_range_u32,
184 	    test_prng_lg_range_u64,
185 	    test_prng_lg_range_zu,
186 	    test_prng_range_u32,
187 	    test_prng_range_u64,
188 	    test_prng_range_zu);
189 }
190