benchtests: Reallocate buffers for every strncmp implementation

Don't reuse buffers for different strncmp implementations since the
earlier implementation will end up warming the cache for the later
one.  Eventually there should be a more elegant way to do this.

	* benchtests/bench-strncmp.c (do_test_limit): Reallocate buffers
	for every implementation.
	(do_test): Likewise.

1 files changed, 53 insertions, 44 deletions

diff --git a/benchtests/bench-strncmp.c b/benchtests/bench-strncmp.c
index 713a07210d..4354d708fb 100644
--- a/benchtests/bench-strncmp.c
+++ b/benchtests/bench-strncmp.c
@@ -139,8 +139,6 @@ do_test_limit (json_ctx_t *json_ctx, size_t align1, size_t align2, size_t len,
 
   if (n == 0)
     {
-      s1 = (CHAR *) (buf1 + page_size);
-      s2 = (CHAR *) (buf2 + page_size);
       json_element_object_begin (json_ctx);
       json_attr_uint (json_ctx, "strlen", (double) len);
       json_attr_uint (json_ctx, "len", (double) n);
@@ -149,7 +147,12 @@ do_test_limit (json_ctx_t *json_ctx, size_t align1, size_t align2, size_t len,
       json_array_begin (json_ctx, "timings");
 
       FOR_EACH_IMPL (impl, 0)
-	do_one_test (json_ctx, impl, s1, s2, n, 0);
+	{
+	  realloc_bufs ();
+	  s1 = (CHAR *) (buf1 + page_size);
+	  s2 = (CHAR *) (buf2 + page_size);
+	  do_one_test (json_ctx, impl, s1, s2, n, 0);
+	}
 
       json_array_end (json_ctx);
       json_element_object_end (json_ctx);
@@ -161,28 +164,6 @@ do_test_limit (json_ctx_t *json_ctx, size_t align1, size_t align2, size_t len,
   align2 &= 15;
   align_n = (page_size - n * CHARBYTES) & 15;
 
-  s1 = (CHAR *) (buf1 + page_size - n * CHARBYTES);
-  s2 = (CHAR *) (buf2 + page_size - n * CHARBYTES);
-
-  if (align1 < align_n)
-    s1 = (CHAR *) ((char *) s1 - (align_n - align1));
-
-  if (align2 < align_n)
-    s2 = (CHAR *) ((char *) s2 - (align_n - align2));
-
-  for (i = 0; i < n; i++)
-    s1[i] = s2[i] = 1 + 23 * i % max_char;
-
-  if (len < n)
-    {
-      s1[len] = 0;
-      s2[len] = 0;
-      if (exp_result < 0)
-	s2[len] = 32;
-      else if (exp_result > 0)
-	s1[len] = 64;
-    }
-
   json_element_object_begin (json_ctx);
   json_attr_uint (json_ctx, "strlen", (double) len);
   json_attr_uint (json_ctx, "len", (double) n);
@@ -191,7 +172,32 @@ do_test_limit (json_ctx_t *json_ctx, size_t align1, size_t align2, size_t len,
   json_array_begin (json_ctx, "timings");
 
   FOR_EACH_IMPL (impl, 0)
-    do_one_test (json_ctx, impl, s1, s2, n, exp_result);
+    {
+      realloc_bufs ();
+      s1 = (CHAR *) (buf1 + page_size - n * CHARBYTES);
+      s2 = (CHAR *) (buf2 + page_size - n * CHARBYTES);
+
+      if (align1 < align_n)
+	s1 = (CHAR *) ((char *) s1 - (align_n - align1));
+
+      if (align2 < align_n)
+	s2 = (CHAR *) ((char *) s2 - (align_n - align2));
+
+      for (i = 0; i < n; i++)
+	s1[i] = s2[i] = 1 + 23 * i % max_char;
+
+      if (len < n)
+	{
+	  s1[len] = 0;
+	  s2[len] = 0;
+	  if (exp_result < 0)
+	    s2[len] = 32;
+	  else if (exp_result > 0)
+	    s1[len] = 64;
+	}
+
+      do_one_test (json_ctx, impl, s1, s2, n, exp_result);
+    }
 
   json_array_end (json_ctx);
   json_element_object_end (json_ctx);
@@ -215,23 +221,6 @@ do_test (json_ctx_t *json_ctx, size_t align1, size_t align2, size_t len, size_t
   if (align2 + (n + 1) * CHARBYTES >= page_size)
     return;
 
-  s1 = (CHAR *) (buf1 + align1);
-  s2 = (CHAR *) (buf2 + align2);
-
-  for (i = 0; i < n; i++)
-    s1[i] = s2[i] = 1 + (23 << ((CHARBYTES - 1) * 8)) * i % max_char;
-
-  s1[n] = 24 + exp_result;
-  s2[n] = 23;
-  s1[len] = 0;
-  s2[len] = 0;
-  if (exp_result < 0)
-    s2[len] = 32;
-  else if (exp_result > 0)
-    s1[len] = 64;
-  if (len >= n)
-    s2[n - 1] -= exp_result;
-
   json_element_object_begin (json_ctx);
   json_attr_uint (json_ctx, "strlen", (double) len);
   json_attr_uint (json_ctx, "len", (double) n);
@@ -240,7 +229,27 @@ do_test (json_ctx_t *json_ctx, size_t align1, size_t align2, size_t len, size_t
   json_array_begin (json_ctx, "timings");
 
   FOR_EACH_IMPL (impl, 0)
-    do_one_test (json_ctx, impl, s1, s2, n, exp_result);
+    {
+      realloc_bufs ();
+      s1 = (CHAR *) (buf1 + align1);
+      s2 = (CHAR *) (buf2 + align2);
+
+      for (i = 0; i < n; i++)
+	s1[i] = s2[i] = 1 + (23 << ((CHARBYTES - 1) * 8)) * i % max_char;
+
+      s1[n] = 24 + exp_result;
+      s2[n] = 23;
+      s1[len] = 0;
+      s2[len] = 0;
+      if (exp_result < 0)
+	s2[len] = 32;
+      else if (exp_result > 0)
+	s1[len] = 64;
+      if (len >= n)
+	s2[n - 1] -= exp_result;
+
+      do_one_test (json_ctx, impl, s1, s2, n, exp_result);
+    }
 
   json_array_end (json_ctx);
   json_element_object_end (json_ctx);