| /* Copy memory to memory until the specified number of bytes |
| has been copied. Overlap is handled correctly. |
| Copyright (C) 1991, 1995, 1996, 1997, 2003 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, write to the Free |
| Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 02111-1307 USA. */ |
| |
| #include <string.h> |
| |
| #include "memcopy.h" |
| #include "pagecopy.h" |
| |
| #ifdef __ARCH_HAS_BWD_MEMCPY__ |
| /* generic-opt memmove assumes memcpy does forward copying! */ |
| #include "_memcpy_fwd.c" |
| #endif |
| |
| |
| static void _wordcopy_bwd_aligned (long int dstp, long int srcp, size_t len) |
| { |
| op_t a0 = 0; |
| op_t a1 = 0; |
| |
| switch (len % 8) |
| { |
| case 2: |
| srcp -= 2 * OPSIZ; |
| dstp -= 1 * OPSIZ; |
| a0 = ((op_t *) srcp)[1]; |
| len += 6; |
| goto do1; |
| case 3: |
| srcp -= 3 * OPSIZ; |
| dstp -= 2 * OPSIZ; |
| a1 = ((op_t *) srcp)[2]; |
| len += 5; |
| goto do2; |
| case 4: |
| srcp -= 4 * OPSIZ; |
| dstp -= 3 * OPSIZ; |
| a0 = ((op_t *) srcp)[3]; |
| len += 4; |
| goto do3; |
| case 5: |
| srcp -= 5 * OPSIZ; |
| dstp -= 4 * OPSIZ; |
| a1 = ((op_t *) srcp)[4]; |
| len += 3; |
| goto do4; |
| case 6: |
| srcp -= 6 * OPSIZ; |
| dstp -= 5 * OPSIZ; |
| a0 = ((op_t *) srcp)[5]; |
| len += 2; |
| goto do5; |
| case 7: |
| srcp -= 7 * OPSIZ; |
| dstp -= 6 * OPSIZ; |
| a1 = ((op_t *) srcp)[6]; |
| len += 1; |
| goto do6; |
| |
| case 0: |
| if (OP_T_THRES <= 3 * OPSIZ && len == 0) |
| return; |
| srcp -= 8 * OPSIZ; |
| dstp -= 7 * OPSIZ; |
| a0 = ((op_t *) srcp)[7]; |
| goto do7; |
| case 1: |
| srcp -= 9 * OPSIZ; |
| dstp -= 8 * OPSIZ; |
| a1 = ((op_t *) srcp)[8]; |
| len -= 1; |
| if (OP_T_THRES <= 3 * OPSIZ && len == 0) |
| goto do0; |
| goto do8; /* No-op. */ |
| } |
| |
| do |
| { |
| do8: |
| a0 = ((op_t *) srcp)[7]; |
| ((op_t *) dstp)[7] = a1; |
| do7: |
| a1 = ((op_t *) srcp)[6]; |
| ((op_t *) dstp)[6] = a0; |
| do6: |
| a0 = ((op_t *) srcp)[5]; |
| ((op_t *) dstp)[5] = a1; |
| do5: |
| a1 = ((op_t *) srcp)[4]; |
| ((op_t *) dstp)[4] = a0; |
| do4: |
| a0 = ((op_t *) srcp)[3]; |
| ((op_t *) dstp)[3] = a1; |
| do3: |
| a1 = ((op_t *) srcp)[2]; |
| ((op_t *) dstp)[2] = a0; |
| do2: |
| a0 = ((op_t *) srcp)[1]; |
| ((op_t *) dstp)[1] = a1; |
| do1: |
| a1 = ((op_t *) srcp)[0]; |
| ((op_t *) dstp)[0] = a0; |
| |
| srcp -= 8 * OPSIZ; |
| dstp -= 8 * OPSIZ; |
| len -= 8; |
| } |
| while (len != 0); |
| |
| /* This is the right position for do0. Please don't move |
| it into the loop. */ |
| do0: |
| ((op_t *) dstp)[7] = a1; |
| } |
| |
| /* _wordcopy_bwd_dest_aligned -- Copy block finishing right |
| before SRCP to block finishing right before DSTP with LEN `op_t' |
| words (not LEN bytes!). DSTP should be aligned for memory |
| operations on `op_t', but SRCP must *not* be aligned. */ |
| |
| static void _wordcopy_bwd_dest_aligned (long int dstp, long int srcp, size_t len) |
| { |
| op_t a0 = 0; |
| op_t a1 = 0; |
| op_t a2 = 0; |
| op_t a3 = 0; |
| int sh_1, sh_2; |
| |
| /* Calculate how to shift a word read at the memory operation |
| aligned srcp to make it aligned for copy. */ |
| |
| sh_1 = 8 * (srcp % OPSIZ); |
| sh_2 = 8 * OPSIZ - sh_1; |
| |
| /* Make srcp aligned by rounding it down to the beginning of the op_t |
| it points in the middle of. */ |
| srcp &= -OPSIZ; |
| srcp += OPSIZ; |
| |
| switch (len % 4) |
| { |
| case 2: |
| srcp -= 3 * OPSIZ; |
| dstp -= 1 * OPSIZ; |
| a2 = ((op_t *) srcp)[2]; |
| a1 = ((op_t *) srcp)[1]; |
| len += 2; |
| goto do1; |
| case 3: |
| srcp -= 4 * OPSIZ; |
| dstp -= 2 * OPSIZ; |
| a3 = ((op_t *) srcp)[3]; |
| a2 = ((op_t *) srcp)[2]; |
| len += 1; |
| goto do2; |
| case 0: |
| if (OP_T_THRES <= 3 * OPSIZ && len == 0) |
| return; |
| srcp -= 5 * OPSIZ; |
| dstp -= 3 * OPSIZ; |
| a0 = ((op_t *) srcp)[4]; |
| a3 = ((op_t *) srcp)[3]; |
| goto do3; |
| case 1: |
| srcp -= 6 * OPSIZ; |
| dstp -= 4 * OPSIZ; |
| a1 = ((op_t *) srcp)[5]; |
| a0 = ((op_t *) srcp)[4]; |
| len -= 1; |
| if (OP_T_THRES <= 3 * OPSIZ && len == 0) |
| goto do0; |
| goto do4; /* No-op. */ |
| } |
| |
| do |
| { |
| do4: |
| a3 = ((op_t *) srcp)[3]; |
| ((op_t *) dstp)[3] = MERGE (a0, sh_1, a1, sh_2); |
| do3: |
| a2 = ((op_t *) srcp)[2]; |
| ((op_t *) dstp)[2] = MERGE (a3, sh_1, a0, sh_2); |
| do2: |
| a1 = ((op_t *) srcp)[1]; |
| ((op_t *) dstp)[1] = MERGE (a2, sh_1, a3, sh_2); |
| do1: |
| a0 = ((op_t *) srcp)[0]; |
| ((op_t *) dstp)[0] = MERGE (a1, sh_1, a2, sh_2); |
| |
| srcp -= 4 * OPSIZ; |
| dstp -= 4 * OPSIZ; |
| len -= 4; |
| } |
| while (len != 0); |
| |
| /* This is the right position for do0. Please don't move |
| it into the loop. */ |
| do0: |
| ((op_t *) dstp)[3] = MERGE (a0, sh_1, a1, sh_2); |
| } |
| |
| void *memmove (void *dest, const void *src, 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! */ |
| { |
| #ifndef __ARCH_HAS_BWD_MEMCPY__ |
| /* Backward memcpy implementation cannot be used */ |
| memcpy(dest, src, len); |
| #else |
| /* Copy from the beginning to the end. */ |
| |
| /* 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 |
| } |
| 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); |
| } |
| libc_hidden_weak(memmove) |