diff options
Diffstat (limited to 'newlib/libc/string/memmove.c')
-rw-r--r-- | newlib/libc/string/memmove.c | 143 |
1 files changed, 0 insertions, 143 deletions
diff --git a/newlib/libc/string/memmove.c b/newlib/libc/string/memmove.c deleted file mode 100644 index 2528e27..0000000 --- a/newlib/libc/string/memmove.c +++ /dev/null @@ -1,143 +0,0 @@ -/* -FUNCTION - <<memmove>>---move possibly overlapping memory - -INDEX - memmove - -ANSI_SYNOPSIS - #include <string.h> - void *memmove(void *<[dst]>, const void *<[src]>, size_t <[length]>); - -TRAD_SYNOPSIS - #include <string.h> - void *memmove(<[dst]>, <[src]>, <[length]>) - void *<[dst]>; - void *<[src]>; - size_t <[length]>; - -DESCRIPTION - This function moves <[length]> characters from the block of - memory starting at <<*<[src]>>> to the memory starting at - <<*<[dst]>>>. <<memmove>> reproduces the characters correctly - at <<*<[dst]>>> even if the two areas overlap. - - -RETURNS - The function returns <[dst]> as passed. - -PORTABILITY -<<memmove>> is ANSI C. - -<<memmove>> requires no supporting OS subroutines. - -QUICKREF - memmove ansi pure -*/ - -#include <string.h> -#include <_ansi.h> -#include <stddef.h> -#include <limits.h> - -/* Nonzero if either X or Y is not aligned on a "long" boundary. */ -#define UNALIGNED(X, Y) \ - (((long)X & (sizeof (long) - 1)) | ((long)Y & (sizeof (long) - 1))) - -/* How many bytes are copied each iteration of the 4X unrolled loop. */ -#define BIGBLOCKSIZE (sizeof (long) << 2) - -/* How many bytes are copied each iteration of the word copy loop. */ -#define LITTLEBLOCKSIZE (sizeof (long)) - -/* Threshhold for punting to the byte copier. */ -#define TOO_SMALL(LEN) ((LEN) < BIGBLOCKSIZE) - -/*SUPPRESS 20*/ -_PTR -_DEFUN (memmove, (dst_void, src_void, length), - _PTR dst_void _AND - _CONST _PTR src_void _AND - size_t length) -{ -#if defined(PREFER_SIZE_OVER_SPEED) || defined(__OPTIMIZE_SIZE__) - char *dst = dst_void; - _CONST char *src = src_void; - - if (src < dst && dst < src + length) - { - /* Have to copy backwards */ - src += length; - dst += length; - while (length--) - { - *--dst = *--src; - } - } - else - { - while (length--) - { - *dst++ = *src++; - } - } - - return dst_void; -#else - char *dst = dst_void; - _CONST char *src = src_void; - long *aligned_dst; - _CONST long *aligned_src; - int len = length; - - if (src < dst && dst < src + len) - { - /* Destructive overlap...have to copy backwards */ - src += len; - dst += len; - while (len--) - { - *--dst = *--src; - } - } - else - { - /* Use optimizing algorithm for a non-destructive copy to closely - match memcpy. If the size is small or either SRC or DST is unaligned, - then punt into the byte copy loop. This should be rare. */ - if (!TOO_SMALL(len) && !UNALIGNED (src, dst)) - { - aligned_dst = (long*)dst; - aligned_src = (long*)src; - - /* Copy 4X long words at a time if possible. */ - while (len >= BIGBLOCKSIZE) - { - *aligned_dst++ = *aligned_src++; - *aligned_dst++ = *aligned_src++; - *aligned_dst++ = *aligned_src++; - *aligned_dst++ = *aligned_src++; - len -= BIGBLOCKSIZE; - } - - /* Copy one long word at a time if possible. */ - while (len >= LITTLEBLOCKSIZE) - { - *aligned_dst++ = *aligned_src++; - len -= LITTLEBLOCKSIZE; - } - - /* Pick up any residual with a byte copier. */ - dst = (char*)aligned_dst; - src = (char*)aligned_src; - } - - while (len--) - { - *dst++ = *src++; - } - } - - return dst_void; -#endif /* not PREFER_SIZE_OVER_SPEED */ -} |