os-k/src/kaleid/common/lib/memory.c

80 lines
2.3 KiB
C

//----------------------------------------------------------------------------//
// GNU GPL OS/K //
// //
// Authors: spectral` //
// NeoX //
// //
// Desc: mem*() functions //
//----------------------------------------------------------------------------//
#include "common/memory.h"
// to be moved
#define QWORD_SIZE 8
#define QWORD_ALIGN 8
//
// Set "qwords"-many aligned qwords starting from ptr to val
//
static inline void *memsetq(void *ptr, ullong uval, size_t qwords)
{
size_t n;
ullong *uptr = (ullong *)ptr;
// aligned memory write
for (n = 0; n < qwords; n++) {
*(uptr + n) = uval;
}
return ptr;
}
//
// Set "bytes"-many bytes starting from ptr to val
// This is most certainely overkill, but I enjoyed doing this
// Alignment stuff barely matters on modern processors
// This may actually be slower than the naive way
//
void *memset(void *ptr, register int val, register size_t bytes)
{
register uchar *uptr = (uchar *)ptr;
const size_t qwords = bytes/QWORD_SIZE;
// get rid of everything after the first byte
val = val & 0xFF;
// deal with bytes before start of the first aligned qword
while (((ullong)uptr % QWORD_ALIGN) > 0 && bytes--) {
*uptr++ = (uchar)val;
}
// move qword by qword
if (qwords) {
const ullong uval = ((ullong)val << 56) | ((ullong)val << 48)
| ((ullong)val << 40) | ((ullong)val << 32)
| ((ullong)val << 24) | ((ullong)val << 16)
| ((ullong)val << 8) | ((ullong)val);
memsetq(uptr, uval, qwords);
uptr += qwords * QWORD_SIZE;
bytes %= QWORD_SIZE;
}
// deal with what's left
while (bytes--) {
*uptr++ = (uchar)val;
}
return ptr;
}
//
// Set "bytes"-many bytes starting from ptr to 0
//
void *memzero(void *ptr, size_t bytes)
{
return memset(ptr, 0, bytes);
}