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).

1 files changed, 151 insertions, 0 deletions

diff --git a/REORG.TODO/sysdeps/tile/tilegx/memset.c b/REORG.TODO/sysdeps/tile/tilegx/memset.c
new file mode 100644
index 0000000000..c6804a9dc6
--- /dev/null
+++ b/REORG.TODO/sysdeps/tile/tilegx/memset.c
@@ -0,0 +1,151 @@
+/* Copyright (C) 2011-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Chris Metcalf <cmetcalf@tilera.com>, 2011.
+
+   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 <arch/chip.h>
+#include <string.h>
+#include <stdint.h>
+#include "string-endian.h"
+
+void * inhibit_loop_to_libcall
+__memset (void *s, int c, size_t n)
+{
+  uint64_t *out64;
+  int n64, to_align64;
+  uint64_t v64;
+  uint8_t *out8 = s;
+
+  /* Experimentation shows that a trivial tight loop is a win up until
+     around a size of 20, where writing a word at a time starts to win.  */
+#define BYTE_CUTOFF 20
+
+#if BYTE_CUTOFF < 7
+  /* This must be at least at least this big, or some code later
+     on doesn't work.  */
+# error "BYTE_CUTOFF is too small."
+#endif
+
+  if (n < BYTE_CUTOFF)
+    {
+      /* Strangely, this turns out to be the tightest way to write
+         this loop.  */
+      if (n != 0)
+        {
+          do
+            {
+              /* Strangely, combining these into one line performs worse.  */
+              *out8 = c;
+              out8++;
+            }
+          while (--n != 0);
+        }
+
+      return s;
+    }
+
+  /* Align 'out8'. We know n >= 7 so this won't write past the end.  */
+  while (((uintptr_t) out8 & 7) != 0)
+    {
+      *out8++ = c;
+      --n;
+    }
+
+  /* Align 'n'. */
+  while (n & 7)
+    out8[--n] = c;
+
+  out64 = (uint64_t *) out8;
+  n64 = n >> 3;
+
+  /* Tile input byte out to 64 bits. */
+  v64 = copy_byte(c);
+
+  /* This must be at least 8 or the following loop doesn't work. */
+#define CACHE_LINE_SIZE_IN_DOUBLEWORDS (CHIP_L2_LINE_SIZE() / 8)
+
+  /* Determine how many words we need to emit before the 'out32'
+     pointer becomes aligned modulo the cache line size.  */
+  to_align64 = (-((uintptr_t) out64 >> 3)) &
+    (CACHE_LINE_SIZE_IN_DOUBLEWORDS - 1);
+
+  /* Only bother aligning and using wh64 if there is at least
+     one full cache line to process.  This check also prevents
+     overrunning the end of the buffer with alignment words.  */
+  if (to_align64 <= n64 - CACHE_LINE_SIZE_IN_DOUBLEWORDS)
+    {
+      int lines_left;
+
+      /* Align out64 mod the cache line size so we can use wh64. */
+      n64 -= to_align64;
+      for (; to_align64 != 0; to_align64--)
+        {
+          *out64 = v64;
+          out64++;
+        }
+
+      /* Use unsigned divide to turn this into a right shift. */
+      lines_left = (unsigned) n64 / CACHE_LINE_SIZE_IN_DOUBLEWORDS;
+
+      do
+        {
+          /* Only wh64 a few lines at a time, so we don't exceed the
+             maximum number of victim lines.  */
+          int x = ((lines_left < CHIP_MAX_OUTSTANDING_VICTIMS ()) ? lines_left
+                   : CHIP_MAX_OUTSTANDING_VICTIMS ());
+          uint64_t *wh = out64;
+          int i = x;
+          int j;
+
+          lines_left -= x;
+
+          do
+            {
+              __insn_wh64 (wh);
+              wh += CACHE_LINE_SIZE_IN_DOUBLEWORDS;
+            }
+          while (--i);
+
+          for (j = x * (CACHE_LINE_SIZE_IN_DOUBLEWORDS / 4); j != 0; j--)
+            {
+              *out64++ = v64;
+              *out64++ = v64;
+              *out64++ = v64;
+              *out64++ = v64;
+            }
+        }
+      while (lines_left != 0);
+
+      /* We processed all full lines above, so only this many
+         words remain to be processed.  */
+      n64 &= CACHE_LINE_SIZE_IN_DOUBLEWORDS - 1;
+    }
+
+  /* Now handle any leftover values. */
+  if (n64 != 0)
+    {
+      do
+        {
+          *out64 = v64;
+          out64++;
+        }
+      while (--n64 != 0);
+    }
+
+  return s;
+}
+weak_alias (__memset, memset)
+libc_hidden_builtin_def (memset)