[PATCH v2] string: Add page tests for test-strncasecmp and test-strncpy

[Raphael Moreira Zinsly]

Adds tests to check if strings placed at page bondaries are
handled correctly by strncasecmp and strncpy similar to tests
for strncmp and strnlen.  This should catch regressions in the
optmized functions.
---
 string/test-strncasecmp.c | 37 +++++++++++++++++++++++++++++++++++++
 string/test-strncpy.c     | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 72 insertions(+)

diff --git a/string/test-strncasecmp.c b/string/test-strncasecmp.c
index 6a9c27beae..bf9838dacb 100644
--- a/string/test-strncasecmp.c
+++ b/string/test-strncasecmp.c
@@ -137,6 +137,42 @@ do_test (size_t align1, size_t align2, size_t n, size_t len, int max_char,
     do_one_test (impl, s1, s2, n, exp_result);
 }
 
+static void
+do_page_tests (void)
+{
+  size_t i, offset, cacheline_size;
+  char *s1, *s2;
+  int exp_result;
+
+  offset = page_size - 1;
+  s1 = (char *) buf1;
+  memset (s1, '\1', offset);
+  s1[offset] = '\0';
+
+  /* s2 has a fixed offset, almost one page long.
+     page_size is actually 2 * getpagesize.  */
+  offset = (page_size / 2) - 10;
+  s2 = strdup (s1) + offset;
+  /* Start offset for s1.  */
+  offset = 3 * page_size / 4;
+  s1 += offset;
+
+  /* Try to cross the page boundary at every offset of a cache line.  */
+  cacheline_size = sysconf (_SC_LEVEL1_DCACHE_LINESIZE);
+  for (i = 0; i < cacheline_size; ++i)
+    {
+      exp_result = *s1;
+
+      FOR_EACH_IMPL (impl, 0)
+	{
+	  check_result (impl, s1, s2, page_size, -exp_result);
+	  check_result (impl, s2, s1, page_size, exp_result);
+	}
+
+      s1++;
+    }
+}
+
 static void
 do_random_tests (void)
 {
@@ -334,6 +370,7 @@ test_locale (const char *locale)
     }
 
   do_random_tests ();
+  do_page_tests ();
 }
 
 int
diff --git a/string/test-strncpy.c b/string/test-strncpy.c
index c978753ad8..fb3332cbac 100644
--- a/string/test-strncpy.c
+++ b/string/test-strncpy.c
@@ -155,6 +155,40 @@ do_test (size_t align1, size_t align2, size_t len, size_t n, int max_char)
     do_one_test (impl, s2, s1, len, n);
 }
 
+static void
+do_page_tests (void)
+{
+  size_t i, small_len, big_len, short_offset, long_offset;
+  CHAR *s1, *s2;
+  /* Calculate the null character offset.  */
+  size_t last_offset = (page_size / sizeof (CHAR)) - 1;
+
+  s2 = (CHAR *) buf1;
+  s1 = (CHAR *) buf2;
+  MEMSET (s1, '\1', last_offset);
+  s1[last_offset] = '\0';
+
+  long_offset = (last_offset + 1) / 2;
+  short_offset = last_offset;
+  for (i = 0; i < 128; i++)
+    {
+      /* Place long strings ending at page boundary.  */
+      long_offset++;
+      big_len = last_offset - long_offset;
+      /* Place short strings ending at page boundary.  */
+      short_offset--;
+      small_len = last_offset - short_offset;
+
+      FOR_EACH_IMPL (impl, 0)
+        {
+	  do_one_test (impl, s2, (CHAR *) (s1 + short_offset), small_len,
+	               small_len);
+	  do_one_test (impl, s2, (CHAR *) (s1 + long_offset), page_size,
+	               big_len);
+	}
+    }
+}
+
 static void
 do_random_tests (void)
 {
@@ -317,6 +351,7 @@ test_main (void)
     }
 
   do_random_tests ();
+  do_page_tests ();
   return ret;
 }
 
-- 
2.26.2