summaryrefslogtreecommitdiffstats
path: root/unittests/Support/BlockFrequencyTest.cpp
blob: f6e3537de91a979bd9a217aa16011fd7e5c9fdd6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
#include "llvm/Support/BlockFrequency.h"
#include "llvm/Support/BranchProbability.h"
#include "llvm/Support/DataTypes.h"
#include "gtest/gtest.h"
#include <climits>

using namespace llvm;

namespace {

TEST(BlockFrequencyTest, OneToZero) {
  BlockFrequency Freq(1);
  BranchProbability Prob(UINT32_MAX - 1, UINT32_MAX);
  Freq *= Prob;
  EXPECT_EQ(Freq.getFrequency(), 0u);

  Freq = BlockFrequency(1);
  Freq *= Prob;
  EXPECT_EQ(Freq.getFrequency(), 0u);
}

TEST(BlockFrequencyTest, OneToOne) {
  BlockFrequency Freq(1);
  BranchProbability Prob(UINT32_MAX, UINT32_MAX);
  Freq *= Prob;
  EXPECT_EQ(Freq.getFrequency(), 1u);

  Freq = BlockFrequency(1);
  Freq *= Prob;
  EXPECT_EQ(Freq.getFrequency(), 1u);
}

TEST(BlockFrequencyTest, ThreeToOne) {
  BlockFrequency Freq(3);
  BranchProbability Prob(3000000, 9000000);
  Freq *= Prob;
  EXPECT_EQ(Freq.getFrequency(), 1u);

  Freq = BlockFrequency(3);
  Freq *= Prob;
  EXPECT_EQ(Freq.getFrequency(), 1u);
}

TEST(BlockFrequencyTest, MaxToHalfMax) {
  BlockFrequency Freq(UINT64_MAX);
  BranchProbability Prob(UINT32_MAX / 2, UINT32_MAX);
  Freq *= Prob;
  EXPECT_EQ(Freq.getFrequency(), 9223372034707292159ULL);

  Freq = BlockFrequency(UINT64_MAX);
  Freq *= Prob;
  EXPECT_EQ(Freq.getFrequency(), 9223372034707292159ULL);
}

TEST(BlockFrequencyTest, BigToBig) {
  const uint64_t Big = 387246523487234346LL;
  const uint32_t P = 123456789;
  BlockFrequency Freq(Big);
  BranchProbability Prob(P, P);
  Freq *= Prob;
  EXPECT_EQ(Freq.getFrequency(), Big);

  Freq = BlockFrequency(Big);
  Freq *= Prob;
  EXPECT_EQ(Freq.getFrequency(), Big);
}

TEST(BlockFrequencyTest, MaxToMax) {
  BlockFrequency Freq(UINT64_MAX);
  BranchProbability Prob(UINT32_MAX, UINT32_MAX);
  Freq *= Prob;
  EXPECT_EQ(Freq.getFrequency(), UINT64_MAX);

  // This additionally makes sure if we have a value equal to our saturating
  // value, we do not signal saturation if the result equals said value, but
  // saturating does not occur.
  Freq = BlockFrequency(UINT64_MAX);
  Freq *= Prob;
  EXPECT_EQ(Freq.getFrequency(), UINT64_MAX);
}

TEST(BlockFrequency, Divide) {
  BlockFrequency Freq(0x3333333333333333ULL);
  Freq /= BranchProbability(1, 2);
  EXPECT_EQ(Freq.getFrequency(), 0x6666666666666666ULL);
}

TEST(BlockFrequencyTest, Saturate) {
  BlockFrequency Freq(0x3333333333333333ULL);
  Freq /= BranchProbability(100, 300);
  EXPECT_EQ(Freq.getFrequency(), 0x9999999999999999ULL);
  Freq /= BranchProbability(1, 2);
  EXPECT_EQ(Freq.getFrequency(), UINT64_MAX);

  Freq = 0x1000000000000000ULL;
  Freq /= BranchProbability(10000, 160000);
  EXPECT_EQ(Freq.getFrequency(), UINT64_MAX);

  // Try to cheat the multiplication overflow check.
  Freq = 0x00000001f0000001ull;
  Freq /= BranchProbability(1000, 0xf000000f);
  EXPECT_EQ(33506781356485509ULL, Freq.getFrequency());
}

TEST(BlockFrequencyTest, SaturatingRightShift) {
  BlockFrequency Freq(0x10080ULL);
  Freq >>= 2;
  EXPECT_EQ(Freq.getFrequency(), 0x4020ULL);
  Freq >>= 20;
  EXPECT_EQ(Freq.getFrequency(), 0x1ULL);
}

}