Adding upstream version 1:10.5.12.upstream/1%10.5.12upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 231 insertions, 0 deletions

diff --git a/mysys/ptr_cmp.c b/mysys/ptr_cmp.c
new file mode 100644
index 00000000..7ea15baf
--- /dev/null
+++ b/mysys/ptr_cmp.c
@@ -0,0 +1,231 @@
+/* Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335  USA */
+
+/*
+  get_ptr_compare(len) returns a pointer to a optimal byte-compare function
+  for a array of stringpointer where all strings have size len.
+  The bytes are compare as unsigned chars.
+  */
+
+#include "mysys_priv.h"
+#include <myisampack.h>
+/*
+ * On some platforms, memcmp() is faster than the unrolled ptr_compare_N
+ * functions, as memcmp() is usually a platform-specific implementation
+ * written in assembler. for example one in /usr/lib/libc/libc_hwcap*.so.1.
+ * on Solaris, or on Windows inside C runtime linrary.
+ *
+ * On Solaris, native implementation is also usually faster than the
+ * built-in memcmp supplied by GCC, so it is recommended to build
+ * with "-fno-builtin-memcmp"in CFLAGS if building with GCC on Solaris.
+ */
+
+/*
+  Daniel Blacks tests shows that libc memcmp is generally faster than
+  ptr_cmp() at least of x86 and power8 platforms, so we use the libc
+  code as deafult for now
+*/
+
+#define USE_NATIVE_MEMCMP 1
+
+#ifdef USE_NATIVE_MEMCMP
+
+#include <string.h>
+
+static int native_compare(size_t *length, unsigned char **a, unsigned char **b)
+{
+  return memcmp(*a, *b, *length);
+}
+
+qsort2_cmp get_ptr_compare (size_t size __attribute__((unused)))
+{
+  return (qsort2_cmp) native_compare;
+}
+
+#else /* USE_NATIVE_MEMCMP */
+
+static int ptr_compare(size_t *compare_length, uchar **a, uchar **b);
+static int ptr_compare_0(size_t *compare_length, uchar **a, uchar **b);
+static int ptr_compare_1(size_t *compare_length, uchar **a, uchar **b);
+static int ptr_compare_2(size_t *compare_length, uchar **a, uchar **b);
+static int ptr_compare_3(size_t *compare_length, uchar **a, uchar **b);
+static int degenerate_compare_func(size_t *compare_length, uchar **a, uchar **b)
+{
+  DBUG_ASSERT(*compare_length == 0);
+  return 0;
+}
+
+qsort2_cmp get_ptr_compare (size_t size)
+{
+  if (size == 0)
+    return (qsort2_cmp) degenerate_compare_func;
+  if (size < 4)
+    return (qsort2_cmp) ptr_compare;
+  switch (size & 3) {
+    case 0: return (qsort2_cmp) ptr_compare_0;
+    case 1: return (qsort2_cmp) ptr_compare_1;
+    case 2: return (qsort2_cmp) ptr_compare_2;
+    case 3: return (qsort2_cmp) ptr_compare_3;
+    }
+  return 0;					/* Impossible */
+}
+	/*
+	  Compare to keys to see witch is smaller.
+	  Loop unrolled to make it quick !!
+	*/
+
+#define cmp(N) if (first[N] != last[N]) return (int) first[N] - (int) last[N]
+
+static int ptr_compare(size_t *compare_length, uchar **a, uchar **b)
+{
+  size_t length= *compare_length;
+  uchar *first,*last;
+
+  DBUG_ASSERT(length > 0);
+  first= *a; last= *b;
+  while (--length)
+  {
+    if (*first++ != *last++)
+      return (int) first[-1] - (int) last[-1];
+  }
+  return (int) first[0] - (int) last[0];
+}
+
+
+static int ptr_compare_0(size_t *compare_length,uchar **a, uchar **b)
+{
+  size_t length= *compare_length;
+  uchar *first,*last;
+
+  first= *a; last= *b;
+ loop:
+  cmp(0);
+  cmp(1);
+  cmp(2);
+  cmp(3);
+  if ((length-=4))
+  {
+    first+=4;
+    last+=4;
+    goto loop;
+  }
+  return (0);
+}
+
+
+static int ptr_compare_1(size_t *compare_length,uchar **a, uchar **b)
+{
+  size_t length= *compare_length-1;
+  uchar *first,*last;
+
+  first= *a+1; last= *b+1;
+  cmp(-1);
+ loop:
+  cmp(0);
+  cmp(1);
+  cmp(2);
+  cmp(3);
+  if ((length-=4))
+  {
+    first+=4;
+    last+=4;
+    goto loop;
+  }
+  return (0);
+}
+
+static int ptr_compare_2(size_t *compare_length,uchar **a, uchar **b)
+{
+  size_t length= *compare_length-2;
+  uchar *first,*last;
+
+  first= *a +2 ; last= *b +2;
+  cmp(-2);
+  cmp(-1);
+ loop:
+  cmp(0);
+  cmp(1);
+  cmp(2);
+  cmp(3);
+  if ((length-=4))
+  {
+    first+=4;
+    last+=4;
+    goto loop;
+  }
+  return (0);
+}
+
+static int ptr_compare_3(size_t *compare_length,uchar **a, uchar **b)
+{
+  size_t length= *compare_length-3;
+  uchar *first,*last;
+
+  first= *a +3 ; last= *b +3;
+  cmp(-3);
+  cmp(-2);
+  cmp(-1);
+ loop:
+  cmp(0);
+  cmp(1);
+  cmp(2);
+  cmp(3);
+  if ((length-=4))
+  {
+    first+=4;
+    last+=4;
+    goto loop;
+  }
+  return (0);
+}
+
+#endif /* USE_NATIVE_MEMCMP */
+
+void my_store_ptr(uchar *buff, size_t pack_length, my_off_t pos)
+{
+  switch (pack_length) {
+#if SIZEOF_OFF_T > 4
+  case 8: mi_int8store(buff,pos); break;
+  case 7: mi_int7store(buff,pos); break;
+  case 6: mi_int6store(buff,pos); break;
+  case 5: mi_int5store(buff,pos); break;
+#endif
+  case 4: mi_int4store(buff,pos); break;
+  case 3: mi_int3store(buff,pos); break;
+  case 2: mi_int2store(buff,pos); break;
+  case 1: buff[0]= (uchar) pos; break;
+  default: DBUG_ASSERT(0);
+  }
+  return;
+}
+
+my_off_t my_get_ptr(uchar *ptr, size_t pack_length)
+{
+  my_off_t pos;
+  switch (pack_length) {
+#if SIZEOF_OFF_T > 4
+  case 8: pos= (my_off_t) mi_uint8korr(ptr); break;
+  case 7: pos= (my_off_t) mi_uint7korr(ptr); break;
+  case 6: pos= (my_off_t) mi_uint6korr(ptr); break;
+  case 5: pos= (my_off_t) mi_uint5korr(ptr); break;
+#endif
+  case 4: pos= (my_off_t) mi_uint4korr(ptr); break;
+  case 3: pos= (my_off_t) mi_uint3korr(ptr); break;
+  case 2: pos= (my_off_t) mi_uint2korr(ptr); break;
+  case 1: pos= (my_off_t) *(uchar*) ptr; break;
+  default: DBUG_ASSERT(0); return 0;
+  }
+ return pos;
+}