Jeff Johnston
24 years ago
13 changed files with 357 additions and 24 deletions
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/*
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FUNCTION |
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<<memccpy>>---copy memory regions with end-token check |
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ANSI_SYNOPSIS |
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#include <string.h> |
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void* memccpy(void *<[out]>, const void *<[in]>, |
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int <[endchar]>, size_t <[n]>); |
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TRAD_SYNOPSIS |
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void *memccpy(<[out]>, <[in]>, <[endchar]>, <[n]> |
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void *<[out]>; |
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void *<[in]>; |
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int <[endchar]>; |
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size_t <[n]>; |
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DESCRIPTION |
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This function copies up to <[n]> bytes from the memory region |
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pointed to by <[in]> to the memory region pointed to by |
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<[out]>. If a byte matching the <[endchar]> is encountered, |
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the byte is copied and copying stops. |
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If the regions overlap, the behavior is undefined. |
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RETURNS |
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<<memccpy>> returns a pointer to the first byte following the |
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<[endchar]> in the <[out]> region. If no byte matching |
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<[endchar]> was copied, then <<NULL>> is returned. |
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PORTABILITY |
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<<memccpy>> is a GNU extension. |
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<<memccpy>> requires no supporting OS subroutines. |
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*/ |
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#include <_ansi.h> |
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#include <stddef.h> |
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#include <string.h> |
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#include <limits.h> |
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/* Nonzero if either X or Y is not aligned on a "long" boundary. */ |
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#define UNALIGNED(X, Y) \ |
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(((long)X & (sizeof (long) - 1)) | ((long)Y & (sizeof (long) - 1))) |
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/* How many bytes are copied each iteration of the word copy loop. */ |
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#define LITTLEBLOCKSIZE (sizeof (long)) |
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/* Threshhold for punting to the byte copier. */ |
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#define TOO_SMALL(LEN) ((LEN) < LITTLEBLOCKSIZE) |
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/* Macros for detecting endchar */ |
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#if LONG_MAX == 2147483647L |
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#define DETECTNULL(X) (((X) - 0x01010101) & ~(X) & 0x80808080) |
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#else |
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#if LONG_MAX == 9223372036854775807L |
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/* Nonzero if X (a long int) contains a NULL byte. */ |
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#define DETECTNULL(X) (((X) - 0x0101010101010101) & ~(X) & 0x8080808080808080) |
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#else |
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#error long int is not a 32bit or 64bit type. |
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#endif |
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#endif |
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_PTR |
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_DEFUN (memccpy, (dst0, src0, endchar, len0), |
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_PTR dst0 _AND |
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_CONST _PTR src0 _AND |
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int endchar0 _AND |
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size_t len0) |
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{ |
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#if defined(PREFER_SIZE_OVER_SPEED) || defined(__OPTIMIZE_SIZE__) |
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_PTR ptr = NULL; |
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char *dst = (char *) dst0; |
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char *src = (char *) src0; |
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char endchar = endchar0 & 0xff; |
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while (len0--) |
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{ |
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if ((*dst++ = *src++) == endchar) |
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{ |
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ptr = dst; |
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break; |
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} |
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} |
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return ptr; |
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#else |
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_PTR ptr = NULL; |
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char *dst = dst0; |
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_CONST char *src = src0; |
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long *aligned_dst; |
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_CONST long *aligned_src; |
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int len = len0; |
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char endchar = endchar0 & 0xff; |
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/* If the size is small, or either SRC or DST is unaligned,
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then punt into the byte copy loop. This should be rare. */ |
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if (!TOO_SMALL(len) && !UNALIGNED (src, dst)) |
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{ |
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int i; |
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unsigned long mask = 0; |
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aligned_dst = (long*)dst; |
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aligned_src = (long*)src; |
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/* The fast code reads the ASCII one word at a time and only
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performs the bytewise search on word-sized segments if they |
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contain the search character, which is detected by XORing |
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the word-sized segment with a word-sized block of the search |
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character and then detecting for the presence of NULL in the |
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result. */ |
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for (i = 0; i < LITTLEBLOCKSIZE; i++) |
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mask = (mask << 8) + endchar; |
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/* Copy one long word at a time if possible. */ |
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while (len >= LITTLEBLOCKSIZE) |
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{ |
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unsigned long buffer = (unsigned long)(*aligned_src); |
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buffer ^= mask; |
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if (DETECTNULL (buffer)) |
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break; /* endchar is found, go byte by byte from here */ |
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*aligned_dst++ = *aligned_src++; |
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len -= LITTLEBLOCKSIZE; |
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} |
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/* Pick up any residual with a byte copier. */ |
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dst = (char*)aligned_dst; |
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src = (char*)aligned_src; |
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} |
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while (len--) |
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{ |
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if ((*dst++ = *src++) == endchar) |
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{ |
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ptr = dst; |
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break; |
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} |
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} |
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return ptr; |
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#endif /* not PREFER_SIZE_OVER_SPEED */ |
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} |
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@ -0,0 +1,108 @@ |
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/*
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FUNCTION |
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<<mempcpy>>---copy memory regions and return end pointer |
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ANSI_SYNOPSIS |
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#include <string.h> |
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void* mempcpy(void *<[out]>, const void *<[in]>, size_t <[n]>); |
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TRAD_SYNOPSIS |
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void *mempcpy(<[out]>, <[in]>, <[n]> |
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void *<[out]>; |
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void *<[in]>; |
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size_t <[n]>; |
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DESCRIPTION |
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This function copies <[n]> bytes from the memory region |
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pointed to by <[in]> to the memory region pointed to by |
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<[out]>. |
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If the regions overlap, the behavior is undefined. |
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RETURNS |
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<<mempcpy>> returns a pointer to the byte following the |
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last byte copied to the <[out]> region. |
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PORTABILITY |
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<<mempcpy>> is a GNU extension. |
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<<mempcpy>> requires no supporting OS subroutines. |
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*/ |
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#include <_ansi.h> |
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#include <stddef.h> |
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#include <limits.h> |
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#include <string.h> |
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/* Nonzero if either X or Y is not aligned on a "long" boundary. */ |
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#define UNALIGNED(X, Y) \ |
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(((long)X & (sizeof (long) - 1)) | ((long)Y & (sizeof (long) - 1))) |
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/* How many bytes are copied each iteration of the 4X unrolled loop. */ |
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#define BIGBLOCKSIZE (sizeof (long) << 2) |
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/* How many bytes are copied each iteration of the word copy loop. */ |
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#define LITTLEBLOCKSIZE (sizeof (long)) |
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/* Threshhold for punting to the byte copier. */ |
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#define TOO_SMALL(LEN) ((LEN) < BIGBLOCKSIZE) |
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_PTR |
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_DEFUN (mempcpy, (dst0, src0, len0), |
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_PTR dst0 _AND |
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_CONST _PTR src0 _AND |
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size_t len0) |
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{ |
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#if defined(PREFER_SIZE_OVER_SPEED) || defined(__OPTIMIZE_SIZE__) |
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char *dst = (char *) dst0; |
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char *src = (char *) src0; |
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while (len0--) |
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{ |
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*dst++ = *src++; |
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} |
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return dst; |
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#else |
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char *dst = dst0; |
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_CONST char *src = src0; |
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long *aligned_dst; |
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_CONST long *aligned_src; |
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int len = len0; |
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/* If the size is small, or either SRC or DST is unaligned,
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then punt into the byte copy loop. This should be rare. */ |
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if (!TOO_SMALL(len) && !UNALIGNED (src, dst)) |
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{ |
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aligned_dst = (long*)dst; |
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aligned_src = (long*)src; |
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/* Copy 4X long words at a time if possible. */ |
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while (len >= BIGBLOCKSIZE) |
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{ |
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*aligned_dst++ = *aligned_src++; |
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*aligned_dst++ = *aligned_src++; |
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*aligned_dst++ = *aligned_src++; |
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*aligned_dst++ = *aligned_src++; |
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len -= BIGBLOCKSIZE; |
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} |
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/* Copy one long word at a time if possible. */ |
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while (len >= LITTLEBLOCKSIZE) |
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{ |
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*aligned_dst++ = *aligned_src++; |
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len -= LITTLEBLOCKSIZE; |
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} |
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/* Pick up any residual with a byte copier. */ |
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dst = (char*)aligned_dst; |
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src = (char*)aligned_src; |
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} |
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while (len--) |
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*dst++ = *src++; |
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return dst; |
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#endif /* not PREFER_SIZE_OVER_SPEED */ |
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} |
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@ -0,0 +1,16 @@ |
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#ifndef _REENT_ONLY |
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#include <_ansi.h> |
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#include <reent.h> |
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#include <stdlib.h> |
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#include <string.h> |
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char * |
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_DEFUN (strndup, (str, n), |
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_CONST char *str _AND |
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size_t n) |
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{ |
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return _strndup_r (_REENT, str, n); |
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} |
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#endif /* !_REENT_ONLY */ |
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@ -0,0 +1,21 @@ |
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#include <reent.h> |
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#include <stdlib.h> |
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#include <string.h> |
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#define MIN(a,b) ((a) < (b) ? (a) : (b)) |
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char * |
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_DEFUN (_strndup_r, (reent_ptr, str, n), |
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struct _reent *reent_ptr _AND |
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_CONST char *str _AND |
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size_t n) |
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{ |
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size_t len = MIN(strlen (str), n); |
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char *copy = _malloc_r (reent_ptr, len + 1); |
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if (copy) |
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{ |
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memcpy (copy, str, len); |
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copy[len] = '\0'; |
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} |
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return copy; |
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} |
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