From: H.J. Lu <hjl.tools@gmail.com>
Date: Wed, 18 May 2016 12:48:56 +0000 (-0700)
Subject: Clear destination buffer updated by the previous run
X-Git-Tag: glibc-2.24~247
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=447720b03b4ac37cbc1367bf3aad56711a30a307;p=thirdparty%2Fglibc.git

Clear destination buffer updated by the previous run

Clear the destination buffer updated by the previous run in bench-memcpy.c
and test-memcpy.c to catch the error when the following implementations do
not copy anything.

	[BZ #19907]
	* benchtests/bench-memcpy.c (do_one_test): Clear the destination
	buffer updated by the previous run.
	* string/test-memcpy.c (do_one_test): Likewise.
	* benchtests/bench-memmove.c (do_one_test): Add a comment.
	* string/test-memmove.c (do_one_test): Likewise.
---

diff --git a/ChangeLog b/ChangeLog
index ce605c1e381..5249fbecfab 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2016-05-18  H.J. Lu  <hongjiu.lu@intel.com>
+
+	[BZ #19907]
+	* benchtests/bench-memcpy.c (do_one_test): Clear the destination
+	buffer updated by the previous run.
+	* string/test-memcpy.c (do_one_test): Likewise.
+	* benchtests/bench-memmove.c (do_one_test): Add a comment.
+	* string/test-memmove.c (do_one_test): Likewise.
+
 2016-05-17  Joseph Myers  <joseph@codesourcery.com>
 
 	[BZ #20094]
diff --git a/benchtests/bench-memcpy.c b/benchtests/bench-memcpy.c
index c5a71925beb..9d9e7b68790 100644
--- a/benchtests/bench-memcpy.c
+++ b/benchtests/bench-memcpy.c
@@ -55,6 +55,10 @@ do_one_test (impl_t *impl, char *dst, const char *src,
   size_t i, iters = INNER_LOOP_ITERS;
   timing_t start, stop, cur;
 
+  /* Must clear the destination buffer set by the previous run.  */
+  for (i = 0; i < len; i++)
+    dst[i] = 0;
+
   if (CALL (impl, dst, src, len) != MEMCPY_RESULT (dst, len))
     {
       error (0, 0, "Wrong result in function %s %p %p", impl->name,
diff --git a/benchtests/bench-memmove.c b/benchtests/bench-memmove.c
index c38596b41e3..3858f2ac52d 100644
--- a/benchtests/bench-memmove.c
+++ b/benchtests/bench-memmove.c
@@ -70,6 +70,7 @@ do_one_test (impl_t *impl, char *dst, char *src, const char *orig_src,
   size_t i, iters = INNER_LOOP_ITERS;
   timing_t start, stop, cur;
 
+  /* This also clears the destination buffer set by the previous run.  */
   memcpy (src, orig_src, len);
 #ifdef TEST_BCOPY
   CALL (impl, src, dst, len);
diff --git a/string/test-memcpy.c b/string/test-memcpy.c
index 2a0994ca98e..cb072f86749 100644
--- a/string/test-memcpy.c
+++ b/string/test-memcpy.c
@@ -53,6 +53,12 @@ static void
 do_one_test (impl_t *impl, char *dst, const char *src,
 	     size_t len)
 {
+  size_t i;
+
+  /* Must clear the destination buffer set by the previous run.  */
+  for (i = 0; i < len; i++)
+    dst[i] = 0;
+
   if (CALL (impl, dst, src, len) != MEMCPY_RESULT (dst, len))
     {
       error (0, 0, "Wrong result in function %s %p %p", impl->name,
diff --git a/string/test-memmove.c b/string/test-memmove.c
index d2ab3f3c8d5..43433297e54 100644
--- a/string/test-memmove.c
+++ b/string/test-memmove.c
@@ -68,6 +68,7 @@ static void
 do_one_test (impl_t *impl, char *dst, char *src, const char *orig_src,
 	     size_t len)
 {
+  /* This also clears the destination buffer set by the previous run.  */
   memcpy (src, orig_src, len);
 #ifdef TEST_BCOPY
   CALL (impl, src, dst, len);