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minor changes

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This commit is contained in:
kub 2019-03-25 19:31:32 +01:00
parent b1a047c926
commit 32feba7458
9 changed files with 151 additions and 78 deletions
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67
platform/common/helix/lib.c
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@ -53,70 +53,5 @@ void *memmove (void *dest, const void *src, size_t n)
return dest;
}
#else
/* memcpy/memmove in C with some simple optimizations.
* ATTN does dirty aliasing tricks with undefined behaviour by standard.
* (this works fine with gcc, though...)
*/
void *memcpy(void *dest, const void *src, size_t n)
{
struct _16 { uint32_t a[4]; };
union { const void *v; char *c; uint64_t *l; struct _16 *s; }
ss = { src }, ds = { dest };
const int lm = sizeof(uint32_t)-1;
if ((((unsigned)ss.c ^ (unsigned)ds.c) & lm) == 0) {
/* fast copy if pointers have the same aligment */
while (((unsigned)ss.c & lm) && n > 0) /* align to word */
*ds.c++ = *ss.c++, n--;
while (n >= sizeof(struct _16)) /* copy 16 bytes blocks */
*ds.s++ = *ss.s++, n -= sizeof(struct _16);
if (n >= sizeof(uint64_t)) /* copy leftover 8 byte block */
*ds.l++ = *ss.l++, n -= sizeof(uint64_t);
} else {
/* byte copy if pointers are unaligned */
while (n >= 8) { /* copy 8 byte blocks */
*ds.c++ = *ss.c++, n--; *ds.c++ = *ss.c++, n--;
*ds.c++ = *ss.c++, n--; *ds.c++ = *ss.c++, n--;
*ds.c++ = *ss.c++, n--; *ds.c++ = *ss.c++, n--;
*ds.c++ = *ss.c++, n--; *ds.c++ = *ss.c++, n--;
}
}
/* copy max. 8 leftover bytes */
while (n > 0)
*ds.c++ = *ss.c++, n--;
return dest;
}
void *memmove (void *dest, const void *src, size_t n)
{
struct _16 { uint32_t a[4]; };
union { const void *v; char *c; uint64_t *l; struct _16 *s; }
ss = { src+n }, ds = { dest+n };
const int lm = sizeof(uint32_t)-1;
if (dest <= src || dest >= src+n)
return memcpy(dest, src, n);
if ((((unsigned)ss.c ^ (unsigned)ds.c) & lm) == 0) {
/* fast copy if pointers have the same aligment */
while (((unsigned)ss.c & lm) && n > 0)
*--ds.c = *--ss.c, n--;
while (n >= sizeof(struct _16))
*--ds.s = *--ss.s, n -= sizeof(struct _16);
if (n >= sizeof(uint64_t))
*--ds.l = *--ss.l, n -= sizeof(uint64_t);
} else {
/* byte copy if pointers are unaligned */
while (n >= 8) {
*--ds.c = *--ss.c, n--; *--ds.c = *--ss.c, n--;
*--ds.c = *--ss.c, n--; *--ds.c = *--ss.c, n--;
*--ds.c = *--ss.c, n--; *--ds.c = *--ss.c, n--;
*--ds.c = *--ss.c, n--; *--ds.c = *--ss.c, n--;
}
}
/* copy max. 8 leftover bytes */
while (n > 0)
*--ds.c = *--ss.c, n--;
return dest;
}
#include "../memcpy.c"
#endif