blob: 0d93799388119057e5acc61442fff265c43a57fa (
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
|
#include "lattice.h"
#include <type_traits>
namespace wasm::analysis {
struct SignLattice {
public:
enum Sign { BOTTOM, NEGATIVE, ZERO, POSITIVE, TOP };
private:
Sign value;
public:
bool isTop() { return value == TOP; }
bool isBottom() { return value == BOTTOM; }
static LatticeComparison compare(const SignLattice& left,
const SignLattice& right) {
if (left.value == right.value) {
return EQUAL;
} else if (left.value == BOTTOM || right.value == TOP) {
return LESS;
} else if (left.value == TOP || right.value == BOTTOM) {
return GREATER;
} else {
return NO_RELATION;
}
}
// Modifies the left lattice element to the least upper bound between
// it and the right hand lattice element in-place. Returns true
// if the left lattice element has been changed.
void getLeastUpperBound(const SignLattice& right) {
if (value == right.value || value == TOP || right.value == BOTTOM) {
return;
} else if (value == BOTTOM || right.value == TOP) {
value = right.value;
} else {
value = TOP;
}
}
};
} // namespace wasm::analysis
|
