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.

1 files changed, 278 insertions, 0 deletions

diff --git a/libc/string/generic/memmove.c b/libc/string/generic/memmove.c
new file mode 100644
index 000000000..21876ce6e
--- /dev/null
+++ b/libc/string/generic/memmove.c
@@ -0,0 +1,278 @@
+/* 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"
+
+static void _wordcopy_bwd_aligned (long int dstp, long int srcp, size_t len)
+{
+  op_t a0, a1;
+
+  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, 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;
+  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!  */
+    {
+#if 1
+#warning REMINDER: generic-opt memmove assumes memcpy does forward copying!
+      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);
+}