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#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;
}
size_t strnlen(const char* str, size_t maxlen)
{
size_t len = 0;
for (; len < maxlen && *str; 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;
}
}
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