PR string/19907: Incorrect memcpy tests

Message ID 20160405050218.GA5157@gmail.com
State Superseded
Headers

Commit Message

H.J. Lu April 5, 2016, 5:02 a.m. UTC
  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
copy anything.

Tested on x86-64.  OK for master?

H.J.
---
	PR string/19907
	* enchtests/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.
---
 benchtests/bench-memcpy.c  | 4 ++++
 benchtests/bench-memmove.c | 1 +
 string/test-memcpy.c       | 6 ++++++
 string/test-memmove.c      | 1 +
 4 files changed, 12 insertions(+)
  

Patch

diff --git a/benchtests/bench-memcpy.c b/benchtests/bench-memcpy.c
index c5a7192..9d9e7b6 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 c38596b..3858f2a 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 2a0994c..cb072f8 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 d2ab3f3..4343329 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);