mirror of
https://github.com/autc04/Retro68.git
synced 2024-12-11 19:49:32 +00:00
165 lines
3.5 KiB
C
165 lines
3.5 KiB
C
/*
|
|
FUNCTION
|
|
<<memcpy>>---copy memory regions, optimized for the mips processors
|
|
|
|
ANSI_SYNOPSIS
|
|
#include <string.h>
|
|
void* memcpy(void *<[out]>, const void *<[in]>, size_t <[n]>);
|
|
|
|
TRAD_SYNOPSIS
|
|
void *memcpy(<[out]>, <[in]>, <[n]>
|
|
void *<[out]>;
|
|
void *<[in]>;
|
|
size_t <[n]>;
|
|
|
|
DESCRIPTION
|
|
This function copies <[n]> bytes from the memory region
|
|
pointed to by <[in]> to the memory region pointed to by
|
|
<[out]>.
|
|
|
|
If the regions overlap, the behavior is undefined.
|
|
|
|
RETURNS
|
|
<<memcpy>> returns a pointer to the first byte of the <[out]>
|
|
region.
|
|
|
|
PORTABILITY
|
|
<<memcpy>> is ANSI C.
|
|
|
|
<<memcpy>> requires no supporting OS subroutines.
|
|
|
|
QUICKREF
|
|
memcpy ansi pure
|
|
*/
|
|
|
|
#include <_ansi.h>
|
|
#include <stddef.h>
|
|
#include <limits.h>
|
|
|
|
#ifdef __mips64
|
|
#define wordtype long long
|
|
#else
|
|
#define wordtype long
|
|
#endif
|
|
|
|
/* Nonzero if either X or Y is not aligned on a "long" boundary. */
|
|
#define UNALIGNED(X, Y) \
|
|
(((long)X & (sizeof (wordtype) - 1)) | ((long)Y & (sizeof (wordtype) - 1)))
|
|
|
|
/* How many bytes are copied each iteration of the 4X unrolled loop. */
|
|
#define BIGBLOCKSIZE (sizeof (wordtype) << 2)
|
|
|
|
/* How many bytes are copied each iteration of the word copy loop. */
|
|
#define LITTLEBLOCKSIZE (sizeof (wordtype))
|
|
|
|
/* Threshhold for punting to the byte copier. */
|
|
#define TOO_SMALL(LEN) ((LEN) < BIGBLOCKSIZE)
|
|
|
|
_PTR
|
|
_DEFUN (memcpy, (dst0, src0, len0),
|
|
_PTR dst0 _AND
|
|
_CONST _PTR src0 _AND
|
|
size_t len0)
|
|
{
|
|
#if defined(PREFER_SIZE_OVER_SPEED) || defined(__OPTIMIZE_SIZE__) || defined(__mips16)
|
|
char *dst = (char *) dst0;
|
|
char *src = (char *) src0;
|
|
|
|
_PTR save = dst0;
|
|
|
|
while (len0--)
|
|
{
|
|
*dst++ = *src++;
|
|
}
|
|
|
|
return save;
|
|
#else
|
|
char *dst = dst0;
|
|
_CONST char *src = src0;
|
|
wordtype *aligned_dst;
|
|
_CONST wordtype *aligned_src;
|
|
int len = len0;
|
|
size_t iter;
|
|
|
|
/* Handle aligned moves here. */
|
|
if (!UNALIGNED (src, dst))
|
|
{
|
|
iter = len / BIGBLOCKSIZE;
|
|
len = len % BIGBLOCKSIZE;
|
|
aligned_dst = (wordtype *)dst;
|
|
aligned_src = (wordtype *)src;
|
|
|
|
/* Copy 4X long or long long words at a time if possible. */
|
|
while (iter > 0)
|
|
{
|
|
wordtype tmp0 = aligned_src[0];
|
|
wordtype tmp1 = aligned_src[1];
|
|
wordtype tmp2 = aligned_src[2];
|
|
wordtype tmp3 = aligned_src[3];
|
|
|
|
aligned_dst[0] = tmp0;
|
|
aligned_dst[1] = tmp1;
|
|
aligned_dst[2] = tmp2;
|
|
aligned_dst[3] = tmp3;
|
|
aligned_src += 4;
|
|
aligned_dst += 4;
|
|
iter--;
|
|
}
|
|
|
|
/* Copy one long or long long word at a time if possible. */
|
|
iter = len / LITTLEBLOCKSIZE;
|
|
len = len % LITTLEBLOCKSIZE;
|
|
|
|
while (iter > 0)
|
|
{
|
|
*aligned_dst++ = *aligned_src++;
|
|
iter--;
|
|
}
|
|
|
|
/* Pick up any residual with a byte copier. */
|
|
dst = (char*)aligned_dst;
|
|
src = (char*)aligned_src;
|
|
|
|
while (len > 0)
|
|
{
|
|
*dst++ = *src++;
|
|
len--;
|
|
}
|
|
|
|
return dst0;
|
|
}
|
|
|
|
/* Handle unaligned moves here, using lwr/lwl and swr/swl where possible */
|
|
else
|
|
{
|
|
#ifndef NO_UNALIGNED_LOADSTORE
|
|
int tmp;
|
|
int *int_src = (int *)src;
|
|
int *int_dst = (int *)dst;
|
|
iter = len / 4;
|
|
len = len % 4;
|
|
while (iter > 0)
|
|
{
|
|
__asm__ ("ulw %0,%1" : "=r" (tmp) : "m" (*int_src));
|
|
iter--;
|
|
int_src++;
|
|
__asm__ ("usw %1,%0" : "=m" (*int_dst) : "r" (tmp));
|
|
int_dst++;
|
|
}
|
|
|
|
/* Pick up any residual with a byte copier. */
|
|
dst = (char*)int_dst;
|
|
src = (char*)int_src;
|
|
#endif
|
|
|
|
while (len > 0)
|
|
{
|
|
*dst++ = *src++;
|
|
len--;
|
|
}
|
|
|
|
return dst0;
|
|
}
|
|
#endif /* not PREFER_SIZE_OVER_SPEED */
|
|
}
|