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authorZack Weinberg <zackw@panix.com>2017-06-08 15:39:03 -0400
committerZack Weinberg <zackw@panix.com>2017-06-08 15:39:03 -0400
commit5046dbb4a7eba5eccfd258f92f4735c9ffc8d069 (patch)
tree4470480d904b65cf14ca524f96f79eca818c3eaf /REORG.TODO/string/memcpy.c
parent199fc19d3aaaf57944ef036e15904febe877fc93 (diff)
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Prepare for radical source tree reorganization. zack/build-layout-experiment
All top-level files and directories are moved into a temporary storage
directory, REORG.TODO, except for files that will certainly still
exist in their current form at top level when we're done (COPYING,
COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which
are moved to the new directory OldChangeLogs, instead), and the
generated file INSTALL (which is just deleted; in the new order, there
will be no generated files checked into version control).
Diffstat (limited to 'REORG.TODO/string/memcpy.c')
-rw-r--r--REORG.TODO/string/memcpy.c60
1 files changed, 60 insertions, 0 deletions
diff --git a/REORG.TODO/string/memcpy.c b/REORG.TODO/string/memcpy.c
new file mode 100644
index 0000000000..974f65ef94
--- /dev/null
+++ b/REORG.TODO/string/memcpy.c
@@ -0,0 +1,60 @@
+/* Copy memory to memory until the specified number of bytes
+   has been copied.  Overlap is NOT 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>
+
+#undef memcpy
+
+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;
+}
+libc_hidden_builtin_def (memcpy)