Electroneum
mul_div.cpp
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31 
32 #include "gtest/gtest.h"
33 
34 #include "int-util.h"
35 
36 namespace
37 {
38  TEST(mul128, handles_zero)
39  {
40  uint64_t hi, lo;
41 
42  lo = mul128(0, 0, &hi);
43  ASSERT_EQ(lo, 0);
44  ASSERT_EQ(hi, 0);
45 
46  lo = mul128(7, 0, &hi);
47  ASSERT_EQ(lo, 0);
48  ASSERT_EQ(hi, 0);
49 
50  lo = mul128(0, 7, &hi);
51  ASSERT_EQ(lo, 0);
52  ASSERT_EQ(hi, 0);
53  }
54 
55  TEST(mul128, handles_one)
56  {
57  uint64_t hi, lo;
58 
59  lo = mul128(1, 1, &hi);
60  ASSERT_EQ(lo, 1);
61  ASSERT_EQ(hi, 0);
62 
63  lo = mul128(7, 1, &hi);
64  ASSERT_EQ(lo, 7);
65  ASSERT_EQ(hi, 0);
66 
67  lo = mul128(1, 7, &hi);
68  ASSERT_EQ(lo, 7);
69  ASSERT_EQ(hi, 0);
70  }
71 
72  TEST(mul128_without_carry, multiplies_correctly)
73  {
74  uint64_t hi, lo;
75 
76  lo = mul128(0x3333333333333333, 5, &hi);
77  ASSERT_EQ(lo, 0xffffffffffffffff);
78  ASSERT_EQ(hi, 0);
79 
80  lo = mul128(5, 0x3333333333333333, &hi);
81  ASSERT_EQ(lo, 0xffffffffffffffff);
82  ASSERT_EQ(hi, 0);
83 
84  lo = mul128(0x1111111111111111, 0x1111111111111111, &hi);
85  ASSERT_EQ(lo, 0x0fedcba987654321);
86  ASSERT_EQ(hi, 0x0123456789abcdf0);;
87  }
88 
89  TEST(mul128_with_carry_1_only, multiplies_correctly)
90  {
91  uint64_t hi, lo;
92 
93  lo = mul128(0xe0000000e0000000, 0xe0000000e0000000, &hi);
94  ASSERT_EQ(lo, 0xc400000000000000);
95  ASSERT_EQ(hi, 0xc400000188000000);
96  }
97 
98  TEST(mul128_with_carry_2_only, multiplies_correctly)
99  {
100  uint64_t hi, lo;
101 
102  lo = mul128(0x10000000ffffffff, 0x10000000ffffffff, &hi);
103  ASSERT_EQ(lo, 0xdffffffe00000001);
104  ASSERT_EQ(hi, 0x0100000020000000);
105  }
106 
107  TEST(mul128_with_carry_1_and_2, multiplies_correctly)
108  {
109  uint64_t hi, lo;
110 
111  lo = mul128(0xf1f2f3f4f5f6f7f8, 0xf9f0fafbfcfdfeff, &hi);
112  ASSERT_EQ(lo, 0x52118e5f3b211008);
113  ASSERT_EQ(hi, 0xec39104363716e59);
114 
115  lo = mul128(0xffffffffffffffff, 0xffffffffffffffff, &hi);
116  ASSERT_EQ(lo, 0x0000000000000001);
117  ASSERT_EQ(hi, 0xfffffffffffffffe);
118  }
119 
120  TEST(div128_32, handles_zero)
121  {
122  uint32_t reminder;
123  uint64_t hi;
124  uint64_t lo;
125 
126  reminder = div128_32(0, 0, 7, &hi, &lo);
127  ASSERT_EQ(reminder, 0);
128  ASSERT_EQ(hi, 0);
129  ASSERT_EQ(lo, 0);
130 
131  // Division by zero is UB, so can be tested correctly
132  }
133 
134  TEST(div128_32, handles_one)
135  {
136  uint32_t reminder;
137  uint64_t hi;
138  uint64_t lo;
139 
140  reminder = div128_32(0, 7, 1, &hi, &lo);
141  ASSERT_EQ(reminder, 0);
142  ASSERT_EQ(hi, 0);
143  ASSERT_EQ(lo, 7);
144 
145  reminder = div128_32(7, 0, 1, &hi, &lo);
146  ASSERT_EQ(reminder, 0);
147  ASSERT_EQ(hi, 7);
148  ASSERT_EQ(lo, 0);
149  }
150 
151  TEST(div128_32, handles_if_dividend_less_divider)
152  {
153  uint32_t reminder;
154  uint64_t hi;
155  uint64_t lo;
156 
157  reminder = div128_32(0, 1383746, 1645825, &hi, &lo);
158  ASSERT_EQ(reminder, 1383746);
159  ASSERT_EQ(hi, 0);
160  ASSERT_EQ(lo, 0);
161  }
162 
163  TEST(div128_32, handles_if_dividend_dwords_less_divider)
164  {
165  uint32_t reminder;
166  uint64_t hi;
167  uint64_t lo;
168 
169  reminder = div128_32(0x5AD629E441074F28, 0x0DBCAB2B231081F1, 0xFE735CD6, &hi, &lo);
170  ASSERT_EQ(reminder, 0xB9C924E9);
171  ASSERT_EQ(hi, 0x000000005B63C274);
172  ASSERT_EQ(lo, 0x9084FC024383E48C);
173  }
174 
175  TEST(div128_32, works_correctly)
176  {
177  uint32_t reminder;
178  uint64_t hi;
179  uint64_t lo;
180 
181  reminder = div128_32(2, 0, 2, &hi, &lo);
182  ASSERT_EQ(reminder, 0);
183  ASSERT_EQ(hi, 1);
184  ASSERT_EQ(lo, 0);
185 
186  reminder = div128_32(0xffffffffffffffff, 0, 0xffffffff, &hi, &lo);
187  ASSERT_EQ(reminder, 0);
188  ASSERT_EQ(hi, 0x0000000100000001);
189  ASSERT_EQ(lo, 0);
190 
191  reminder = div128_32(0xffffffffffffffff, 5846, 0xffffffff, &hi, &lo);
192  ASSERT_EQ(reminder, 5846);
193  ASSERT_EQ(hi, 0x0000000100000001);
194  ASSERT_EQ(lo, 0);
195 
196  reminder = div128_32(0xffffffffffffffff - 1, 0, 0xffffffff, &hi, &lo);
197  ASSERT_EQ(reminder, 0xfffffffe);
198  ASSERT_EQ(hi, 0x0000000100000000);
199  ASSERT_EQ(lo, 0xfffffffefffffffe);
200 
201  reminder = div128_32(0x2649372534875028, 0xaedbfedc5adbc739, 0x27826534, &hi, &lo);
202  ASSERT_EQ(reminder, 0x1a6dc2e5);
203  ASSERT_EQ(hi, 0x00000000f812c1f8);
204  ASSERT_EQ(lo, 0xddf2fdb09bc2e2e9);
205  }
206 }
#define TEST(test_case_name, test_name)
Definition: gtest.h:2187
#define ASSERT_EQ(val1, val2)
Definition: gtest.h:1956
unsigned int uint32_t
Definition: stdint.h:126
unsigned __int64 uint64_t
Definition: stdint.h:136