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
|
// Copyright (c) 2025 Federico Angelilli
// Licensed under the 3-Clause BSD License
// See fedang.net/posts/pointer-tagging
#include <stdio.h>
#include <stdlib.h>
//#include "lowbits.c"
//#include "highbits.c"
#include "union.c"
void print_binary(value_t v) {
const size_t n = sizeof(value_t) / sizeof(uintptr_t);
uintptr_t ls[n];
memcpy(ls, &v, sizeof(value_t));
for (int i = 0; i < n; i++) {
for (int j = 8 * sizeof(uintptr_t) - 1; j >= 0; j--) {
putchar((ls[i] >> j) & 1 ? '1' : '0');
}
puts("");
}
}
int main() {
// Object
{
void *obj = malloc(123);
value_t v = VALUE_FROM_OBJECT(obj);
printf("Object %p\nTagged: ", obj);
print_binary(v);
puts("");
assert(VALUE_IS_OBJECT(v));
assert(VALUE_TO_OBJECT(v) == obj);
}
// Integer
{
intptr_t ls[] = {
-1, 10, 1000000, INTEGER_MAX, INTEGER_MIN, 424242, -10000
};
for (int i = 0; i < sizeof(ls)/sizeof(*ls); i++) {
value_t v = VALUE_FROM_INTEGER(ls[i]);
printf("Integer %ld\nTagged: ", ls[i]);
print_binary(v);
puts("");
assert(VALUE_IS_INTEGER(v));
assert(ls[i] == VALUE_TO_INTEGER(v));
}
}
// Float
{
float ls[] = {
-1.0, 88.88, 10e-16, 199.9876e12, -1111111111
};
for (int i = 0; i < sizeof(ls)/sizeof(*ls); i++) {
value_t v = VALUE_FROM_FLOAT(ls[i]);
printf("Float %f\nTagged: ", ls[i]);
print_binary(v);
puts("");
assert(VALUE_IS_FLOAT(v));
assert(ls[i] == VALUE_TO_FLOAT(v));
}
}
// String
{
char *str = malloc(20);
strcpy(str, "Hello, World");
value_t v = VALUE_FROM_STRING(str);
printf("String %s\nTagged: ", str);
print_binary(v);
puts("");
assert(VALUE_IS_STRING(v));
assert(VALUE_TO_STRING(v) == str);
}
// Tiny string
{
tinystr_t s1 = { "Short" };
value_t v1 = VALUE_FROM_TINYSTR(s1);
printf("Tiny string %s\nTagged: ", s1.data);
print_binary(v1);
puts("");
assert(!memcmp(s1.data, VALUE_TO_TINYSTR(v1).data, 8));
tinystr_t s2 = { "1234567" };
value_t v2 = VALUE_FROM_TINYSTR(s2);
printf("Tiny string %s\nTagged: ", s2.data);
print_binary(v2);
puts("");
assert(!memcmp(s2.data, VALUE_TO_TINYSTR(v2).data, 8));
}
return 0;
}
|
