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Diffstat (limited to 'newlib/libc/string/memccpy.c')
| -rw-r--r-- | newlib/libc/string/memccpy.c | 145 |
1 files changed, 0 insertions, 145 deletions
diff --git a/newlib/libc/string/memccpy.c b/newlib/libc/string/memccpy.c deleted file mode 100644 index f677ac02e..000000000 --- a/newlib/libc/string/memccpy.c +++ /dev/null @@ -1,145 +0,0 @@ -/* -FUNCTION - <<memccpy>>---copy memory regions with end-token check - -ANSI_SYNOPSIS - #include <string.h> - void* memccpy(void *<[out]>, const void *<[in]>, - int <[endchar]>, size_t <[n]>); - -TRAD_SYNOPSIS - void *memccpy(<[out]>, <[in]>, <[endchar]>, <[n]> - void *<[out]>; - void *<[in]>; - int <[endchar]>; - size_t <[n]>; - -DESCRIPTION - This function copies up to <[n]> bytes from the memory region - pointed to by <[in]> to the memory region pointed to by - <[out]>. If a byte matching the <[endchar]> is encountered, - the byte is copied and copying stops. - - If the regions overlap, the behavior is undefined. - -RETURNS - <<memccpy>> returns a pointer to the first byte following the - <[endchar]> in the <[out]> region. If no byte matching - <[endchar]> was copied, then <<NULL>> is returned. - -PORTABILITY -<<memccpy>> is a GNU extension. - -<<memccpy>> requires no supporting OS subroutines. - - */ - -#include <_ansi.h> -#include <stddef.h> -#include <string.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 word copy loop. */ -#define LITTLEBLOCKSIZE (sizeof (long)) - -/* Threshhold for punting to the byte copier. */ -#define TOO_SMALL(LEN) ((LEN) < LITTLEBLOCKSIZE) - -/* Macros for detecting endchar */ -#if LONG_MAX == 2147483647L -#define DETECTNULL(X) (((X) - 0x01010101) & ~(X) & 0x80808080) -#else -#if LONG_MAX == 9223372036854775807L -/* Nonzero if X (a long int) contains a NULL byte. */ -#define DETECTNULL(X) (((X) - 0x0101010101010101) & ~(X) & 0x8080808080808080) -#else -#error long int is not a 32bit or 64bit type. -#endif -#endif - - -_PTR -_DEFUN (memccpy, (dst0, src0, endchar, len0), - _PTR dst0 _AND - _CONST _PTR src0 _AND - int endchar0 _AND - size_t len0) -{ - -#if defined(PREFER_SIZE_OVER_SPEED) || defined(__OPTIMIZE_SIZE__) - _PTR ptr = NULL; - char *dst = (char *) dst0; - char *src = (char *) src0; - char endchar = endchar0 & 0xff; - - while (len0--) - { - if ((*dst++ = *src++) == endchar) - { - ptr = dst; - break; - } - } - - return ptr; -#else - _PTR ptr = NULL; - char *dst = dst0; - _CONST char *src = src0; - long *aligned_dst; - _CONST long *aligned_src; - int len = len0; - char endchar = endchar0 & 0xff; - - /* 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)) - { - int i; - unsigned long mask = 0; - - aligned_dst = (long*)dst; - aligned_src = (long*)src; - - /* The fast code reads the ASCII one word at a time and only - performs the bytewise search on word-sized segments if they - contain the search character, which is detected by XORing - the word-sized segment with a word-sized block of the search - character and then detecting for the presence of NULL in the - result. */ - for (i = 0; i < LITTLEBLOCKSIZE; i++) - mask = (mask << 8) + endchar; - - - /* Copy one long word at a time if possible. */ - while (len >= LITTLEBLOCKSIZE) - { - unsigned long buffer = (unsigned long)(*aligned_src); - buffer ^= mask; - if (DETECTNULL (buffer)) - break; /* endchar is found, go byte by byte from here */ - *aligned_dst++ = *aligned_src++; - len -= LITTLEBLOCKSIZE; - } - - /* Pick up any residual with a byte copier. */ - dst = (char*)aligned_dst; - src = (char*)aligned_src; - } - - while (len--) - { - if ((*dst++ = *src++) == endchar) - { - ptr = dst; - break; - } - } - - return ptr; -#endif /* not PREFER_SIZE_OVER_SPEED */ -} |