ladybird/AK/StdLibExtras.cpp
Robin Burchell 0dc9af5f7e Add clang-format file
Also run it across the whole tree to get everything using the One True Style.
We don't yet run this in an automated fashion as it's a little slow, but
there is a snippet to do so in makeall.sh.
2019-05-28 17:31:20 +02:00

155 lines
3.4 KiB
C++

#include <AK/Assertions.h>
#include <AK/StdLibExtras.h>
#include <AK/Types.h>
#include <AK/kstdio.h>
extern "C" {
#ifndef KERNEL
void* mmx_memcpy(void* dest, const void* src, size_t len)
{
ASSERT(len >= 1024);
auto* dest_ptr = (byte*)dest;
auto* src_ptr = (const byte*)src;
if ((dword)dest_ptr & 7) {
dword prologue = 8 - ((dword)dest_ptr & 7);
len -= prologue;
asm volatile(
"rep movsb\n"
: "=S"(src_ptr), "=D"(dest_ptr), "=c"(prologue)
: "0"(src_ptr), "1"(dest_ptr), "2"(prologue)
: "memory");
}
for (dword i = len / 64; i; --i) {
asm volatile(
"movq (%0), %%mm0\n"
"movq 8(%0), %%mm1\n"
"movq 16(%0), %%mm2\n"
"movq 24(%0), %%mm3\n"
"movq 32(%0), %%mm4\n"
"movq 40(%0), %%mm5\n"
"movq 48(%0), %%mm6\n"
"movq 56(%0), %%mm7\n"
"movq %%mm0, (%1)\n"
"movq %%mm1, 8(%1)\n"
"movq %%mm2, 16(%1)\n"
"movq %%mm3, 24(%1)\n"
"movq %%mm4, 32(%1)\n"
"movq %%mm5, 40(%1)\n"
"movq %%mm6, 48(%1)\n"
"movq %%mm7, 56(%1)\n" ::"r"(src_ptr),
"r"(dest_ptr)
: "memory");
src_ptr += 64;
dest_ptr += 64;
}
asm volatile("emms" ::
: "memory");
// Whatever remains we'll have to memcpy.
len %= 64;
if (len)
memcpy(dest_ptr, src_ptr, len);
return dest;
}
#endif
#ifdef KERNEL
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;
}
#endif
}