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
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
|
//===- llvm/unittest/Support/KnownBitsTest.cpp - KnownBits tests ----------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements unit tests for KnownBits functions.
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/KnownBits.h"
#include "gtest/gtest.h"
using namespace llvm;
namespace {
template<typename FnTy>
void ForeachKnownBits(unsigned Bits, FnTy Fn) {
unsigned Max = 1 << Bits;
KnownBits Known(Bits);
for (unsigned Zero = 0; Zero < Max; ++Zero) {
for (unsigned One = 0; One < Max; ++One) {
Known.Zero = Zero;
Known.One = One;
if (Known.hasConflict())
continue;
Fn(Known);
}
}
}
template<typename FnTy>
void ForeachNumInKnownBits(const KnownBits &Known, FnTy Fn) {
unsigned Bits = Known.getBitWidth();
unsigned Max = 1 << Bits;
for (unsigned N = 0; N < Max; ++N) {
APInt Num(Bits, N);
if ((Num & Known.Zero) != 0 || (~Num & Known.One) != 0)
continue;
Fn(Num);
}
}
TEST(KnownBitsTest, AddCarryExhaustive) {
unsigned Bits = 4;
ForeachKnownBits(Bits, [&](const KnownBits &Known1) {
ForeachKnownBits(Bits, [&](const KnownBits &Known2) {
ForeachKnownBits(1, [&](const KnownBits &KnownCarry) {
// Explicitly compute known bits of the addition by trying all
// possibilities.
KnownBits Known(Bits);
Known.Zero.setAllBits();
Known.One.setAllBits();
ForeachNumInKnownBits(Known1, [&](const APInt &N1) {
ForeachNumInKnownBits(Known2, [&](const APInt &N2) {
ForeachNumInKnownBits(KnownCarry, [&](const APInt &Carry) {
APInt Add = N1 + N2;
if (Carry.getBoolValue())
++Add;
Known.One &= Add;
Known.Zero &= ~Add;
});
});
});
KnownBits KnownComputed = KnownBits::computeForAddCarry(
Known1, Known2, KnownCarry);
EXPECT_EQ(Known.Zero, KnownComputed.Zero);
EXPECT_EQ(Known.One, KnownComputed.One);
});
});
});
}
static void TestAddSubExhaustive(bool IsAdd) {
unsigned Bits = 4;
ForeachKnownBits(Bits, [&](const KnownBits &Known1) {
ForeachKnownBits(Bits, [&](const KnownBits &Known2) {
KnownBits Known(Bits), KnownNSW(Bits);
Known.Zero.setAllBits();
Known.One.setAllBits();
KnownNSW.Zero.setAllBits();
KnownNSW.One.setAllBits();
ForeachNumInKnownBits(Known1, [&](const APInt &N1) {
ForeachNumInKnownBits(Known2, [&](const APInt &N2) {
bool Overflow;
APInt Res;
if (IsAdd)
Res = N1.sadd_ov(N2, Overflow);
else
Res = N1.ssub_ov(N2, Overflow);
Known.One &= Res;
Known.Zero &= ~Res;
if (!Overflow) {
KnownNSW.One &= Res;
KnownNSW.Zero &= ~Res;
}
});
});
KnownBits KnownComputed = KnownBits::computeForAddSub(
IsAdd, /*NSW*/false, Known1, Known2);
EXPECT_EQ(Known.Zero, KnownComputed.Zero);
EXPECT_EQ(Known.One, KnownComputed.One);
// The NSW calculation is not precise, only check that it's
// conservatively correct.
KnownBits KnownNSWComputed = KnownBits::computeForAddSub(
IsAdd, /*NSW*/true, Known1, Known2);
EXPECT_TRUE(KnownNSWComputed.Zero.isSubsetOf(KnownNSW.Zero));
EXPECT_TRUE(KnownNSWComputed.One.isSubsetOf(KnownNSW.One));
});
});
}
TEST(KnownBitsTest, AddSubExhaustive) {
TestAddSubExhaustive(true);
TestAddSubExhaustive(false);
}
} // end anonymous namespace
|
