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
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
|
#include <AK/Assertions.h>
#include <AK/Types.h>
#include <Kernel/kmalloc.h>
extern "C" {
void* memcpy(void* dest_ptr, const void* src_ptr, size_t n)
{
size_t dest = (size_t)dest_ptr;
size_t src = (size_t)src_ptr;
// FIXME: Support starting at an unaligned address.
if (!(dest & 0x3) && !(src & 0x3) && n >= 12) {
size_t size_ts = n / sizeof(size_t);
asm volatile(
"rep movsl\n"
: "=S"(src), "=D"(dest)
: "S"(src), "D"(dest), "c"(size_ts)
: "memory");
n -= size_ts * sizeof(size_t);
if (n == 0)
return dest_ptr;
}
asm volatile(
"rep movsb\n" ::"S"(src), "D"(dest), "c"(n)
: "memory");
return dest_ptr;
}
void* memmove(void* dest, const void* src, size_t n)
{
if (dest < src)
return memcpy(dest, src, n);
u8* pd = (u8*)dest;
const u8* ps = (const u8*)src;
for (pd += n, ps += n; n--;)
*--pd = *--ps;
return dest;
}
char* strcpy(char* dest, const char* src)
{
auto* dest_ptr = dest;
auto* src_ptr = src;
while ((*dest_ptr++ = *src_ptr++) != '\0')
;
return dest;
}
char* strncpy(char* dest, const char* src, size_t n)
{
size_t i;
for (i = 0; i < n && src[i] != '\0'; ++i)
dest[i] = src[i];
for (; i < n; ++i)
dest[i] = '\0';
return dest;
}
void* memset(void* dest_ptr, int c, size_t n)
{
size_t dest = (size_t)dest_ptr;
// FIXME: Support starting at an unaligned address.
if (!(dest & 0x3) && n >= 12) {
size_t size_ts = n / sizeof(size_t);
size_t expanded_c = (u8)c;
expanded_c |= expanded_c << 8;
expanded_c |= expanded_c << 16;
asm volatile(
"rep stosl\n"
: "=D"(dest)
: "D"(dest), "c"(size_ts), "a"(expanded_c)
: "memory");
n -= size_ts * sizeof(size_t);
if (n == 0)
return dest_ptr;
}
asm volatile(
"rep stosb\n"
: "=D"(dest), "=c"(n)
: "0"(dest), "1"(n), "a"(c)
: "memory");
return dest_ptr;
}
char* strrchr(const char* str, int ch)
{
char* last = nullptr;
char c;
for (; (c = *str); ++str) {
if (c == ch)
last = const_cast<char*>(str);
}
return last;
}
size_t strlen(const char* str)
{
size_t len = 0;
while (*(str++))
++len;
return len;
}
int strcmp(const char* s1, const char* s2)
{
for (; *s1 == *s2; ++s1, ++s2) {
if (*s1 == 0)
return 0;
}
return *(const u8*)s1 < *(const u8*)s2 ? -1 : 1;
}
char* strdup(const char* str)
{
size_t len = strlen(str);
char* new_str = (char*)kmalloc(len + 1);
strcpy(new_str, str);
return new_str;
}
int memcmp(const void* v1, const void* v2, size_t n)
{
auto* s1 = (const u8*)v1;
auto* s2 = (const u8*)v2;
while (n-- > 0) {
if (*s1++ != *s2++)
return s1[-1] < s2[-1] ? -1 : 1;
}
return 0;
}
[[noreturn]] void __cxa_pure_virtual()
{
ASSERT_NOT_REACHED();
}
static inline uint32_t divq(uint64_t n, uint32_t d)
{
uint32_t n1 = n >> 32;
uint32_t n0 = n;
uint32_t q;
uint32_t r;
asm volatile("divl %4"
: "=d"(r), "=a"(q)
: "0"(n1), "1"(n0), "rm"(d));
return q;
}
static uint64_t unsigned_divide64(uint64_t n, uint64_t d)
{
if ((d >> 32) == 0) {
uint64_t b = 1ULL << 32;
uint32_t n1 = n >> 32;
uint32_t n0 = n;
uint32_t d0 = d;
return divq(b * (n1 % d0) + n0, d0) + b * (n1 / d0);
}
if (n < d)
return 0;
uint32_t d1 = d >> 32u;
int s = __builtin_clz(d1);
uint64_t q = divq(n >> 1, (d << s) >> 32) >> (31 - s);
return n - (q - 1) * d < d ? q - 1 : q;
}
static uint32_t unsigned_modulo64(uint64_t n, uint64_t d)
{
return n - d * unsigned_divide64(n, d);
}
static int64_t signed_divide64(int64_t n, int64_t d)
{
uint64_t n_abs = n >= 0 ? (uint64_t)n : -(uint64_t)n;
uint64_t d_abs = d >= 0 ? (uint64_t)d : -(uint64_t)d;
uint64_t q_abs = unsigned_divide64(n_abs, d_abs);
return (n < 0) == (d < 0) ? (int64_t)q_abs : -(int64_t)q_abs;
}
static int32_t signed_modulo64(int64_t n, int64_t d)
{
return n - d * signed_divide64(n, d);
}
int64_t __divdi3(int64_t n, int64_t d)
{
return signed_divide64(n, d);
}
int64_t __moddi3(int64_t n, int64_t d)
{
return signed_modulo64(n, d);
}
uint64_t __udivdi3(uint64_t n, uint64_t d)
{
return unsigned_divide64(n, d);
}
uint64_t __umoddi3(uint64_t n, uint64_t d)
{
return unsigned_modulo64(n, d);
}
uint64_t __udivmoddi4(uint64_t n, uint64_t d, uint64_t* r)
{
uint64_t q = 0;
uint64_t qbit = 1;
if (!d)
return 1 / ((unsigned)d);
while ((int64_t)d >= 0) {
d <<= 1;
qbit <<= 1;
}
while (qbit) {
if (d <= n) {
n -= d;
q += qbit;
}
d >>= 1;
qbit >>= 1;
}
if (r)
*r = n;
return q;
}
}
|
