openMSX
Math_test.cc
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1#include "catch.hpp"
2#include "Math.hh"
3
4TEST_CASE("Math::clipToInt16")
5{
6 CHECK(Math::clipToInt16(-100000) == -32768);
7 CHECK(Math::clipToInt16( -32769) == -32768);
8 CHECK(Math::clipToInt16( -32768) == -32768);
9 CHECK(Math::clipToInt16( -32767) == -32767);
10 CHECK(Math::clipToInt16( -10000) == -10000);
11 CHECK(Math::clipToInt16( -10) == -10);
12 CHECK(Math::clipToInt16( -1) == -1);
13 CHECK(Math::clipToInt16( 0) == 0);
14 CHECK(Math::clipToInt16( 1) == 1);
15 CHECK(Math::clipToInt16( 10) == 10);
16 CHECK(Math::clipToInt16( 9876) == 9876);
17 CHECK(Math::clipToInt16( 32766) == 32766);
18 CHECK(Math::clipToInt16( 32767) == 32767);
19 CHECK(Math::clipToInt16( 32768) == 32767);
20 CHECK(Math::clipToInt16( 100000) == 32767);
21
22 CHECK(Math::clipToInt16(-10'000'000'000ll) == -32768);
23 CHECK(Math::clipToInt16( 17ll) == 17);
24 CHECK(Math::clipToInt16( 10'000'000'000ll) == 32767);
25}
26
27TEST_CASE("Math::clipIntToByte")
28{
29 CHECK(Math::clipIntToByte(-100) == 0);
30 CHECK(Math::clipIntToByte( -27) == 0);
31 CHECK(Math::clipIntToByte( -1) == 0);
32 CHECK(Math::clipIntToByte( 0) == 0);
33 CHECK(Math::clipIntToByte( 1) == 1);
34 CHECK(Math::clipIntToByte( 10) == 10);
35 CHECK(Math::clipIntToByte( 127) == 127);
36 CHECK(Math::clipIntToByte( 128) == 128);
37 CHECK(Math::clipIntToByte( 222) == 222);
38 CHECK(Math::clipIntToByte( 255) == 255);
39 CHECK(Math::clipIntToByte( 256) == 255);
40 CHECK(Math::clipIntToByte( 257) == 255);
41 CHECK(Math::clipIntToByte( 327) == 255);
42}
43
44static void testReverseNBits(unsigned x, unsigned n, unsigned expected)
45{
46 CHECK(Math::reverseNBits(x, n) == expected);
47 CHECK(Math::reverseNBits(expected, n) == x);
48}
49TEST_CASE("Math::reverseNBits")
50{
51 testReverseNBits(0x0, 4, 0x0);
52 testReverseNBits(0x1, 4, 0x8);
53 testReverseNBits(0x2, 4, 0x4);
54 testReverseNBits(0x3, 4, 0xC);
55 testReverseNBits(0x4, 4, 0x2);
56 testReverseNBits(0x8, 4, 0x1);
57 testReverseNBits(0x6, 4, 0x6);
58 testReverseNBits(0xE, 4, 0x7);
59 testReverseNBits(0xF, 4, 0xF);
60 testReverseNBits(0x00012345, 22, 0x0028B120);
61 testReverseNBits(0x0010000F, 32, 0xF0000800);
62}
63
64static void testReverseByte(uint8_t x, uint8_t expected)
65{
66 CHECK(Math::reverseByte (x ) == expected);
67 CHECK(Math::reverseNBits(x, 8) == expected);
68
69 CHECK(Math::reverseByte (expected ) == x);
70 CHECK(Math::reverseNBits(expected, 8) == x);
71}
72TEST_CASE("Math::reverseByte")
73{
74 testReverseByte(0x00, 0x00);
75 testReverseByte(0x01, 0x80);
76 testReverseByte(0x02, 0x40);
77 testReverseByte(0x07, 0xE0);
78 testReverseByte(0x12, 0x48);
79 testReverseByte(0x73, 0xCE);
80 testReverseByte(0x7F, 0xFE);
81 testReverseByte(0x8C, 0x31);
82 testReverseByte(0xAB, 0xD5);
83 testReverseByte(0xE4, 0x27);
84 testReverseByte(0xF0, 0x0F);
85}
86
87TEST_CASE("Math::floodRight")
88{
89 CHECK(Math::floodRight(0u) == 0);
90 CHECK(Math::floodRight(1u) == 1);
91 CHECK(Math::floodRight(2u) == 3);
92 CHECK(Math::floodRight(3u) == 3);
93 CHECK(Math::floodRight(4u) == 7);
94 CHECK(Math::floodRight(5u) == 7);
95 CHECK(Math::floodRight(6u) == 7);
96 CHECK(Math::floodRight(7u) == 7);
97 CHECK(Math::floodRight(8u) == 15);
98 CHECK(Math::floodRight(9u) == 15);
99 CHECK(Math::floodRight(15u) == 15);
100 CHECK(Math::floodRight(16u) == 31);
101 CHECK(Math::floodRight(32u) == 63);
102 CHECK(Math::floodRight(64u) == 127);
103 CHECK(Math::floodRight(12345u) == 16383);
104 CHECK(Math::floodRight(0x7F001234u) == 0x7FFFFFFF);
105 CHECK(Math::floodRight(0x80000000u) == 0xFFFFFFFF);
106 CHECK(Math::floodRight(0xF0FEDCBAu) == 0xFFFFFFFF);
107 CHECK(Math::floodRight(0x1234F0FEDCBAULL) == 0x1FFFFFFFFFFFULL);
108 CHECK(Math::floodRight(uint8_t(0x12)) == uint8_t(0x1F));
109 CHECK(Math::floodRight(uint16_t(0x2512)) == uint16_t(0x3FFF));
110}
111
112TEST_CASE("Math::div_mod_floor")
113{
114 auto test = [](int D, int d, int q, int r) {
115 REQUIRE(d * q + r == D);
116 auto qr = Math::div_mod_floor(D, d);
117 CHECK(qr.quotient == q);
118 CHECK(qr.remainder == r);
119 };
120 test( 10, 3, 3, 1);
121 test(-10, 3, -4, 2);
122 test( 10, -3, -4, -2);
123 test(-10, -3, 3, -1);
124
125 test( 10, 2, 5, 0);
126 test(-10, 2, -5, 0);
127 test( 10, -2, -5, 0);
128 test(-10, -2, 5, 0);
129}
test
void test(const IterableBitSet< N > &s, std::initializer_list< size_t > list)
Definition: IterableBitSet_test.cc:19
TEST_CASE
TEST_CASE("Math::clipToInt16")
Definition: Math_test.cc:4
CHECK
CHECK(m3==m3)
Math::div_mod_floor
constexpr QuotientRemainder div_mod_floor(int dividend, int divisor)
Definition: Math.hh:188
Math::reverseNBits
constexpr unsigned reverseNBits(unsigned x, unsigned bits)
Reverse the lower N bits of a given value.
Definition: Math.hh:75
Math::floodRight
constexpr auto floodRight(std::unsigned_integral auto x) noexcept
Returns the smallest number of the form 2^n-1 that is greater or equal to the given number.
Definition: Math.hh:32
Math::clipIntToByte
uint8_t clipIntToByte(int x)
Clip x to range [0,255].
Definition: Math.hh:61
Math::clipToInt16
int16_t clipToInt16(T x)
Clip x to range [-32768,32767].
Definition: Math.hh:47
Math::reverseByte
constexpr uint8_t reverseByte(uint8_t a)
Reverse the bits in a byte.
Definition: Math.hh:125
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