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Diffstat (limited to 'REORG.TODO/string/memmove.c')
| -rw-r--r-- | REORG.TODO/string/memmove.c | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/REORG.TODO/string/memmove.c b/REORG.TODO/string/memmove.c new file mode 100644 index 0000000000..d8c2116b01 --- /dev/null +++ b/REORG.TODO/string/memmove.c @@ -0,0 +1,115 @@ +/* Copy memory to memory until the specified number of bytes + has been copied. Overlap is handled correctly. + Copyright (C) 1991-2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Torbjorn Granlund (tege@sics.se). + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <string.h> +#include <memcopy.h> + +/* All this is so that bcopy.c can #include + this file after defining some things. */ +#ifndef a1 +#define a1 dest /* First arg is DEST. */ +#define a1const +#define a2 src /* Second arg is SRC. */ +#define a2const const +#undef memmove +#endif +#if !defined(RETURN) || !defined(rettype) +#define RETURN(s) return (s) /* Return DEST. */ +#define rettype void * +#endif + +#ifndef MEMMOVE +#define MEMMOVE memmove +#endif + +rettype +inhibit_loop_to_libcall +MEMMOVE (a1const void *a1, a2const void *a2, size_t len) +{ + unsigned long int dstp = (long int) dest; + unsigned long int srcp = (long int) src; + + /* This test makes the forward copying code be used whenever possible. + Reduces the working set. */ + if (dstp - srcp >= len) /* *Unsigned* compare! */ + { + /* Copy from the beginning to the end. */ + +#if MEMCPY_OK_FOR_FWD_MEMMOVE + dest = memcpy (dest, src, len); +#else + /* If there not too few bytes to copy, use word copy. */ + if (len >= OP_T_THRES) + { + /* Copy just a few bytes to make DSTP aligned. */ + len -= (-dstp) % OPSIZ; + BYTE_COPY_FWD (dstp, srcp, (-dstp) % OPSIZ); + + /* Copy whole pages from SRCP to DSTP by virtual address + manipulation, as much as possible. */ + + PAGE_COPY_FWD_MAYBE (dstp, srcp, len, len); + + /* Copy from SRCP to DSTP taking advantage of the known + alignment of DSTP. Number of bytes remaining is put + in the third argument, i.e. in LEN. This number may + vary from machine to machine. */ + + WORD_COPY_FWD (dstp, srcp, len, len); + + /* Fall out and copy the tail. */ + } + + /* There are just a few bytes to copy. Use byte memory operations. */ + BYTE_COPY_FWD (dstp, srcp, len); +#endif /* MEMCPY_OK_FOR_FWD_MEMMOVE */ + } + else + { + /* Copy from the end to the beginning. */ + srcp += len; + dstp += len; + + /* If there not too few bytes to copy, use word copy. */ + if (len >= OP_T_THRES) + { + /* Copy just a few bytes to make DSTP aligned. */ + len -= dstp % OPSIZ; + BYTE_COPY_BWD (dstp, srcp, dstp % OPSIZ); + + /* Copy from SRCP to DSTP taking advantage of the known + alignment of DSTP. Number of bytes remaining is put + in the third argument, i.e. in LEN. This number may + vary from machine to machine. */ + + WORD_COPY_BWD (dstp, srcp, len, len); + + /* Fall out and copy the tail. */ + } + + /* There are just a few bytes to copy. Use byte memory operations. */ + BYTE_COPY_BWD (dstp, srcp, len); + } + + RETURN (dest); +} +#ifndef memmove +libc_hidden_builtin_def (memmove) +#endif |