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authorManuel Novoa III <mjn3@codepoet.org>2004-09-02 14:39:38 +0000
committerManuel Novoa III <mjn3@codepoet.org>2004-09-02 14:39:38 +0000
commitbec90733b9de6e7d75b8bda19b3f0a7117e6b78d (patch)
tree474ca0f3b80b7990ff33e547d42c1e7dc3014e3b /libc/string/generic/memcpy.c
parentc4cedfc718426337b0215c256c184d2b4e20cd06 (diff)
Add a couple of mips-specific string funcs.
Port the generic optimized string funcs from glibc, with some tweaks to cut their size a little. The main change is making memmove call memcpy for forward copying to trim redundant code. Make use of both the generic and arch-specific speed-optimized string funcs configurable. Arch-specific take precedence over generic, and generic takes precedence over basic size-optimized uClibc funcs.
Diffstat (limited to 'libc/string/generic/memcpy.c')
-rw-r--r--libc/string/generic/memcpy.c246
1 files changed, 246 insertions, 0 deletions
diff --git a/libc/string/generic/memcpy.c b/libc/string/generic/memcpy.c
new file mode 100644
index 000000000..9851fdea6
--- /dev/null
+++ b/libc/string/generic/memcpy.c
@@ -0,0 +1,246 @@
+/* Copy memory to memory until the specified number of bytes
+ has been copied. Overlap is NOT handled correctly.
+ Copyright (C) 1991, 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"
+
+#undef memcpy
+
+/* _wordcopy_fwd_aligned -- Copy block beginning at SRCP to
+ block beginning at DSTP with LEN `op_t' words (not LEN bytes!).
+ Both SRCP and DSTP should be aligned for memory operations on `op_t's. */
+
+static void _wordcopy_fwd_aligned (long int dstp, long int srcp, size_t len)
+{
+ op_t a0, a1;
+
+ switch (len % 8)
+ {
+ case 2:
+ a0 = ((op_t *) srcp)[0];
+ srcp -= 6 * OPSIZ;
+ dstp -= 7 * OPSIZ;
+ len += 6;
+ goto do1;
+ case 3:
+ a1 = ((op_t *) srcp)[0];
+ srcp -= 5 * OPSIZ;
+ dstp -= 6 * OPSIZ;
+ len += 5;
+ goto do2;
+ case 4:
+ a0 = ((op_t *) srcp)[0];
+ srcp -= 4 * OPSIZ;
+ dstp -= 5 * OPSIZ;
+ len += 4;
+ goto do3;
+ case 5:
+ a1 = ((op_t *) srcp)[0];
+ srcp -= 3 * OPSIZ;
+ dstp -= 4 * OPSIZ;
+ len += 3;
+ goto do4;
+ case 6:
+ a0 = ((op_t *) srcp)[0];
+ srcp -= 2 * OPSIZ;
+ dstp -= 3 * OPSIZ;
+ len += 2;
+ goto do5;
+ case 7:
+ a1 = ((op_t *) srcp)[0];
+ srcp -= 1 * OPSIZ;
+ dstp -= 2 * OPSIZ;
+ len += 1;
+ goto do6;
+
+ case 0:
+ if (OP_T_THRES <= 3 * OPSIZ && len == 0)
+ return;
+ a0 = ((op_t *) srcp)[0];
+ srcp -= 0 * OPSIZ;
+ dstp -= 1 * OPSIZ;
+ goto do7;
+ case 1:
+ a1 = ((op_t *) srcp)[0];
+ srcp -=-1 * OPSIZ;
+ dstp -= 0 * OPSIZ;
+ len -= 1;
+ if (OP_T_THRES <= 3 * OPSIZ && len == 0)
+ goto do0;
+ goto do8; /* No-op. */
+ }
+
+ do
+ {
+ do8:
+ a0 = ((op_t *) srcp)[0];
+ ((op_t *) dstp)[0] = a1;
+ do7:
+ a1 = ((op_t *) srcp)[1];
+ ((op_t *) dstp)[1] = a0;
+ do6:
+ a0 = ((op_t *) srcp)[2];
+ ((op_t *) dstp)[2] = a1;
+ do5:
+ a1 = ((op_t *) srcp)[3];
+ ((op_t *) dstp)[3] = a0;
+ do4:
+ a0 = ((op_t *) srcp)[4];
+ ((op_t *) dstp)[4] = a1;
+ do3:
+ a1 = ((op_t *) srcp)[5];
+ ((op_t *) dstp)[5] = a0;
+ do2:
+ a0 = ((op_t *) srcp)[6];
+ ((op_t *) dstp)[6] = a1;
+ do1:
+ a1 = ((op_t *) srcp)[7];
+ ((op_t *) dstp)[7] = 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)[0] = a1;
+}
+
+/* _wordcopy_fwd_dest_aligned -- Copy block beginning at SRCP to
+ block beginning at DSTP with LEN `op_t' words (not LEN bytes!).
+ DSTP should be aligned for memory operations on `op_t's, but SRCP must
+ *not* be aligned. */
+
+static void _wordcopy_fwd_dest_aligned (long int dstp, long int srcp, size_t len)
+{
+ op_t a0, a1, a2, a3;
+ 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;
+
+ switch (len % 4)
+ {
+ case 2:
+ a1 = ((op_t *) srcp)[0];
+ a2 = ((op_t *) srcp)[1];
+ srcp -= 1 * OPSIZ;
+ dstp -= 3 * OPSIZ;
+ len += 2;
+ goto do1;
+ case 3:
+ a0 = ((op_t *) srcp)[0];
+ a1 = ((op_t *) srcp)[1];
+ srcp -= 0 * OPSIZ;
+ dstp -= 2 * OPSIZ;
+ len += 1;
+ goto do2;
+ case 0:
+ if (OP_T_THRES <= 3 * OPSIZ && len == 0)
+ return;
+ a3 = ((op_t *) srcp)[0];
+ a0 = ((op_t *) srcp)[1];
+ srcp -=-1 * OPSIZ;
+ dstp -= 1 * OPSIZ;
+ len += 0;
+ goto do3;
+ case 1:
+ a2 = ((op_t *) srcp)[0];
+ a3 = ((op_t *) srcp)[1];
+ srcp -=-2 * OPSIZ;
+ dstp -= 0 * OPSIZ;
+ len -= 1;
+ if (OP_T_THRES <= 3 * OPSIZ && len == 0)
+ goto do0;
+ goto do4; /* No-op. */
+ }
+
+ do
+ {
+ do4:
+ a0 = ((op_t *) srcp)[0];
+ ((op_t *) dstp)[0] = MERGE (a2, sh_1, a3, sh_2);
+ do3:
+ a1 = ((op_t *) srcp)[1];
+ ((op_t *) dstp)[1] = MERGE (a3, sh_1, a0, sh_2);
+ do2:
+ a2 = ((op_t *) srcp)[2];
+ ((op_t *) dstp)[2] = MERGE (a0, sh_1, a1, sh_2);
+ do1:
+ a3 = ((op_t *) srcp)[3];
+ ((op_t *) dstp)[3] = 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)[0] = MERGE (a2, sh_1, a3, sh_2);
+}
+
+void *memcpy (void *dstpp, const void *srcpp, size_t len)
+{
+ unsigned long int dstp = (long int) dstpp;
+ unsigned long int srcp = (long int) srcpp;
+
+ /* 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);
+
+ return dstpp;
+}