[PATCH] memrchr testcase

[Adhemerval Zanella <azanella at linux dot vnet dot ibm dot com>]

Hi all,

When reviewing the PPC LE patches from Alan I noticed GLIBC don't have a
memrchr testcase. In fact when I was coding this path I found out an
issue with POWER7 implementation which Alan's memchr/memrch patch
already addresses (so I won't bother sending the patch).

I used the memchr one as base and adjusting for a reverse search (I removed
from the check with a large len which obvious generate invalid memory accesses).

Checked on PPC32, PPC64, x86, x86_64.

---

2013-08-29  Adhemerval Zanella  <azanella@linux.vnet.ibm.com>

	* string/test-memrchr.c: New file.
	* string/test-memrchr-ifunc.c: New file.
	* string/Makefile: Add new memrchr testcase.

--

diff --git a/string/Makefile b/string/Makefile
index 0237edd..72d3e29 100644
--- a/string/Makefile
+++ b/string/Makefile
@@ -45,7 +45,7 @@ strop-tests	:= memchr memcmp memcpy memmove mempcpy memset memccpy	\
 		   stpcpy stpncpy strcat strchr strcmp strcpy strcspn	\
 		   strlen strncmp strncpy strpbrk strrchr strspn memmem	\
 		   strstr strcasestr strnlen strcasecmp strncasecmp	\
-		   strncat rawmemchr strchrnul bcopy bzero
+		   strncat rawmemchr strchrnul bcopy bzero memrchr
 tests		:= tester inl-tester noinl-tester testcopy test-ffs	\
 		   tst-strlen stratcliff tst-svc tst-inlcall		\
 		   bug-strncat1 bug-strspn1 bug-strpbrk1 tst-bswap	\
diff --git a/string/test-memrchr-ifunc.c b/string/test-memrchr-ifunc.c
new file mode 100644
index 0000000..100dedb
--- /dev/null
+++ b/string/test-memrchr-ifunc.c
@@ -0,0 +1,20 @@
+/* Test and measure IFUNC implementations of memrchr function.
+   Copyright (C) 2013 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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/>.  */
+
+#define TEST_IFUNC 1
+#include "test-memrchr.c"
diff --git a/string/test-memrchr.c b/string/test-memrchr.c
new file mode 100644
index 0000000..a4fe811
--- /dev/null
+++ b/string/test-memrchr.c
@@ -0,0 +1,169 @@
+/* Test and measure memrchr functions.
+   Copyright (C) 2013 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Written by Jakub Jelinek <jakub@redhat.com>, 1999.
+
+   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/>.  */
+
+#define TEST_MAIN
+#define TEST_NAME "memrchr"
+#include "test-string.h"
+
+typedef char *(*proto_t) (const char *, int, size_t);
+char *simple_memrchr (const char *, int, size_t);
+
+IMPL (simple_memrchr, 0)
+IMPL (memrchr, 1)
+
+char *
+simple_memrchr (const char *s, int c, size_t n)
+{
+  s = s + n;
+  while (n--)
+    if (*--s == (char) c)
+      return (char *) s;
+  return NULL;
+}
+
+static void
+do_one_test (impl_t *impl, const char *s, int c, size_t n, char *exp_res)
+{
+  char *res = CALL (impl, s, c, n);
+  if (res != exp_res)
+    {
+      error (0, 0, "Wrong result in function %s %p %p", impl->name,
+	     res, exp_res);
+      ret = 1;
+      return;
+    }
+}
+
+static void
+do_test (size_t align, size_t pos, size_t len, int seek_char)
+{
+  size_t i;
+  char *result;
+
+  align &= 7;
+  if (align + len >= page_size)
+    return;
+
+  for (i = 0; i < len; ++i)
+    {
+      buf1[align + i] = 1 + 23 * i % 127;
+      if (buf1[align + i] == seek_char)
+        buf1[align + i] = seek_char + 1;
+    }
+  buf1[align + len] = 0;
+
+  if (pos < len)
+    {
+      buf1[align + pos] = seek_char;
+      buf1[align + len] = -seek_char;
+      result = (char *) (buf1 + align + pos);
+    }
+  else
+    {
+      result = NULL;
+      buf1[align + len] = seek_char;
+    }
+
+  FOR_EACH_IMPL (impl, 0)
+    do_one_test (impl, (char *) (buf1 + align), seek_char, len, result);
+}
+
+static void
+do_random_tests (void)
+{
+  size_t i, j, n, align, pos, len;
+  int seek_char;
+  char *result;
+  unsigned char *p = buf1 + page_size - 512;
+
+  for (n = 0; n < ITERATIONS; n++)
+    {
+      align = random () & 15;
+      pos = random () & 511;
+      if (pos + align >= 512)
+	pos = 511 - align - (random () & 7);
+      len = random () & 511;
+      if (pos >= len)
+	len = pos + (random () & 7);
+      if (len + align >= 512)
+        len = 512 - align - (random () & 7);
+      seek_char = random () & 255;
+      j = len + align + 64;
+      if (j > 512)
+        j = 512;
+
+      for (i = 0; i < j; i++)
+	{
+	  if (i == pos + align)
+	    p[i] = seek_char;
+	  else
+	    {
+	      p[i] = random () & 255;
+	      if (p[i] == seek_char)
+		p[i] = seek_char + 13;
+	    }
+	}
+
+      if (pos < len)
+	result = (char *) (p + pos + align);
+      else
+	result = NULL;
+
+      FOR_EACH_IMPL (impl, 1)
+	if (CALL (impl, (char *) (p + align), seek_char, len) != result)
+	  {
+	    error (0, 0, "Iteration %zd - wrong result in function %s (%zd, %d, %zd, %zd) %p != %p, p %p",
+		   n, impl->name, align, seek_char, len, pos,
+		   CALL (impl, (char *) (p + align), seek_char, len),
+		   result, p);
+	    ret = 1;
+	  }
+    }
+}
+
+int
+test_main (void)
+{
+  size_t i;
+
+  test_init ();
+
+  printf ("%20s", "");
+  FOR_EACH_IMPL (impl, 0)
+    printf ("\t%s", impl->name);
+  putchar ('\n');
+
+  for (i = 1; i < 8; ++i)
+    {
+      do_test (0, 16 << i, 2048, 23);
+      do_test (i, 64, 256, 23);
+      do_test (0, 16 << i, 2048, 0);
+      do_test (i, 64, 256, 0);
+    }
+  for (i = 1; i < 32; ++i)
+    {
+      do_test (0, i, i + 1, 23);
+      do_test (0, i, i + 1, 0);
+    }
+
+  do_random_tests ();
+  return ret;
+}
+
+#include "../test-skeleton.c"