diff mbox series

[v6,2/2] x86: Expanding test-memmove.c, test-memcpy.c, bench-memcpy-large.c

Message ID 20210402202643.3345849-2-goldstein.w.n@gmail.com
State New
Headers show
Series [v6,1/2] x86: Update large memcpy case in memmove-vec-unaligned-erms.S | expand

Commit Message

Noah Goldstein April 2, 2021, 8:26 p.m. UTC 
From: noah <goldstein.w.n@gmail.com>

No Bug. This commit expanding the range of tests / benchmarks for
memmove and memcpy. The test expansion is mostly in the vein of
increasing the maximum size, increasing the number of unique
alignments tested, and testing both source < destination and vice
versa. The benchmark expansaion is just to increase the number of
unique alignments. test-memcpy, test-memccpy, test-mempcpy,
test-memmove, and tst-memmove-overflow all pass.

Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com>
---
 benchtests/bench-memcpy-large.c |  8 +++-
 string/test-memcpy.c            | 61 ++++++++++++++++------------
 string/test-memmove.c           | 70 ++++++++++++++++++++-------------
 3 files changed, 83 insertions(+), 56 deletions(-)

Comments

H.J. Lu April 2, 2021, 8:35 p.m. UTC | #1 
On Fri, Apr 2, 2021 at 1:26 PM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
>
> From: noah <goldstein.w.n@gmail.com>
>
> No Bug. This commit expanding the range of tests / benchmarks for
> memmove and memcpy. The test expansion is mostly in the vein of
> increasing the maximum size, increasing the number of unique
> alignments tested, and testing both source < destination and vice
> versa. The benchmark expansaion is just to increase the number of
> unique alignments. test-memcpy, test-memccpy, test-mempcpy,
> test-memmove, and tst-memmove-overflow all pass.
>
> Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com>
> ---
>  benchtests/bench-memcpy-large.c |  8 +++-
>  string/test-memcpy.c            | 61 ++++++++++++++++------------
>  string/test-memmove.c           | 70 ++++++++++++++++++++-------------
>  3 files changed, 83 insertions(+), 56 deletions(-)
>
> diff --git a/benchtests/bench-memcpy-large.c b/benchtests/bench-memcpy-large.c
> index 3df1575514..efb9627b1e 100644
> --- a/benchtests/bench-memcpy-large.c
> +++ b/benchtests/bench-memcpy-large.c
> @@ -57,11 +57,11 @@ do_test (json_ctx_t *json_ctx, size_t align1, size_t align2, size_t len)
>    size_t i, j;
>    char *s1, *s2;
>
> -  align1 &= 63;
> +  align1 &= 4095;
>    if (align1 + len >= page_size)
>      return;
>
> -  align2 &= 63;
> +  align2 &= 4095;
>    if (align2 + len >= page_size)
>      return;
>
> @@ -113,6 +113,10 @@ test_main (void)
>        do_test (&json_ctx, 0, 3, i + 15);
>        do_test (&json_ctx, 3, 0, i + 31);
>        do_test (&json_ctx, 3, 5, i + 63);
> +      do_test (&json_ctx, 0, 127, i);
> +      do_test (&json_ctx, 0, 255, i);
> +      do_test (&json_ctx, 0, 256, i);
> +      do_test (&json_ctx, 0, 4064, i);
>      }
>
>    json_array_end (&json_ctx);
> diff --git a/string/test-memcpy.c b/string/test-memcpy.c
> index 2e9c6bd099..c9dfc88fed 100644
> --- a/string/test-memcpy.c
> +++ b/string/test-memcpy.c
> @@ -82,11 +82,11 @@ do_test (size_t align1, size_t align2, size_t len)
>    size_t i, j;
>    char *s1, *s2;
>
> -  align1 &= 63;
> +  align1 &= 4095;
>    if (align1 + len >= page_size)
>      return;
>
> -  align2 &= 63;
> +  align2 &= 4095;
>    if (align2 + len >= page_size)
>      return;
>
> @@ -213,11 +213,9 @@ do_random_tests (void)
>  }
>
>  static void
> -do_test1 (void)
> +do_test1 (size_t size)
>  {
> -  size_t size = 0x100000;
>    void *large_buf;
> -
>    large_buf = mmap (NULL, size * 2 + page_size, PROT_READ | PROT_WRITE,
>                     MAP_PRIVATE | MAP_ANON, -1, 0);
>    if (large_buf == MAP_FAILED)
> @@ -233,27 +231,32 @@ do_test1 (void)
>    uint32_t *dest = large_buf;
>    uint32_t *src = large_buf + size + page_size;
>    size_t i;
> -
> -  for (i = 0; i < arrary_size; i++)
> -    src[i] = (uint32_t) i;
> -
> -  FOR_EACH_IMPL (impl, 0)
> +  size_t repeats;
> +  for(repeats = 0; repeats < 2; repeats++)
>      {
> -      memset (dest, -1, size);
> -      CALL (impl, (char *) dest, (char *) src, size);
>        for (i = 0; i < arrary_size; i++)
> -       if (dest[i] != src[i])
> -         {
> -           error (0, 0,
> -                  "Wrong result in function %s dst \"%p\" src \"%p\" offset \"%zd\"",
> -                  impl->name, dest, src, i);
> -           ret = 1;
> -           break;
> -         }
> +        src[i] = (uint32_t) i;
> +
> +      FOR_EACH_IMPL (impl, 0)
> +        {
> +            printf ("\t\tRunning: %s\n", impl->name);
> +          memset (dest, -1, size);
> +          CALL (impl, (char *) dest, (char *) src, size);
> +          for (i = 0; i < arrary_size; i++)
> +        if (dest[i] != src[i])
> +          {
> +            error (0, 0,
> +               "Wrong result in function %s dst \"%p\" src \"%p\" offset \"%zd\"",
> +               impl->name, dest, src, i);
> +            ret = 1;
> +            munmap ((void *) large_buf, size * 2 + page_size);
> +            return;
> +          }
> +        }
> +      dest = src;
> +      src = large_buf;
>      }
> -
> -  munmap ((void *) dest, size);
> -  munmap ((void *) src, size);
> +  munmap ((void *) large_buf, size * 2 + page_size);
>  }
>
>  int
> @@ -275,7 +278,6 @@ test_main (void)
>        do_test (0, i, 1 << i);
>        do_test (i, i, 1 << i);
>      }
> -
>    for (i = 0; i < 32; ++i)
>      {
>        do_test (0, 0, i);
> @@ -294,12 +296,19 @@ test_main (void)
>        do_test (i, i, 16 * i);
>      }
>
> +  for (i = 19; i <= 25; ++i)
> +    {
> +      do_test (255, 0, 1 << i);
> +      do_test (0, 255, i);
> +      do_test (0, 4000, i);
> +    }
> +
>    do_test (0, 0, getpagesize ());
>
>    do_random_tests ();
>
> -  do_test1 ();
> -
> +  do_test1 (0x100000);
> +  do_test1 (0x2000000);
>    return ret;
>  }
>
> diff --git a/string/test-memmove.c b/string/test-memmove.c
> index 2e3ce75b9b..ff8099d12f 100644
> --- a/string/test-memmove.c
> +++ b/string/test-memmove.c
> @@ -247,7 +247,7 @@ do_random_tests (void)
>  }
>
>  static void
> -do_test2 (void)
> +do_test2 (size_t offset)
>  {
>    size_t size = 0x20000000;
>    uint32_t * large_buf;
> @@ -268,33 +268,45 @@ do_test2 (void)
>      }
>
>    size_t bytes_move = 0x80000000 - (uintptr_t) large_buf;
> +  if (bytes_move + offset * sizeof (uint32_t) > size)
> +    {
> +      munmap ((void *) large_buf, size);
> +      return;
> +    }
>    size_t arr_size = bytes_move / sizeof (uint32_t);
>    size_t i;
> -
> -  FOR_EACH_IMPL (impl, 0)
> -    {
> -      for (i = 0; i < arr_size; i++)
> -        large_buf[i] = (uint32_t) i;
> -
> -      uint32_t * dst = &large_buf[33];
> -
> -#ifdef TEST_BCOPY
> -      CALL (impl, (char *) large_buf, (char *) dst, bytes_move);
> -#else
> -      CALL (impl, (char *) dst, (char *) large_buf, bytes_move);
> -#endif
> -
> -      for (i = 0; i < arr_size; i++)
> -       {
> -         if (dst[i] != (uint32_t) i)
> -           {
> -             error (0, 0,
> -                    "Wrong result in function %s dst \"%p\" src \"%p\" offset \"%zd\"",
> -                    impl->name, dst, large_buf, i);
> -             ret = 1;
> -             break;
> -           }
> -       }
> +  size_t repeats;
> +  uint32_t * src = large_buf;
> +  uint32_t * dst = &large_buf[offset];
> +  for (repeats = 0; repeats < 2; ++repeats)
> +    {
            ^  Trailing whitespaces.

> +      FOR_EACH_IMPL (impl, 0)
> +        {
> +          for (i = 0; i < arr_size; i++)
> +            src[i] = (uint32_t) i;
> +
> +
> +    #ifdef TEST_BCOPY
> +          CALL (impl, (char *) src, (char *) dst, bytes_move);
> +    #else
> +          CALL (impl, (char *) dst, (char *) src, bytes_move);
> +    #endif
> +
> +          for (i = 0; i < arr_size; i++)
> +        {
> +          if (dst[i] != (uint32_t) i)
> +            {
> +              error (0, 0,
> +                 "Wrong result in function %s dst \"%p\" src \"%p\" offset \"%zd\"",
> +                 impl->name, dst, large_buf, i);
> +              ret = 1;
> +              munmap ((void *) large_buf, size);
> +              return;
> +            }
> +        }
> +        }
> +      src = dst;
> +      dst = large_buf;
>      }
>
>    munmap ((void *) large_buf, size);
> @@ -340,8 +352,10 @@ test_main (void)
>
>    do_random_tests ();
>
> -  do_test2 ();
> -
> +  do_test2 (33);
> +  do_test2 (0x200000);
> +  do_test2 (0x4000000 - 1);
> +  do_test2 (0x4000000);
>    return ret;
>  }
>
> --
> 2.29.2
>
Noah Goldstein April 2, 2021, 9:35 p.m. UTC | #2 
On Fri, Apr 2, 2021 at 4:36 PM H.J. Lu <hjl.tools@gmail.com> wrote:
>
> On Fri, Apr 2, 2021 at 1:26 PM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
> >
> > From: noah <goldstein.w.n@gmail.com>
> >
> > No Bug. This commit expanding the range of tests / benchmarks for
> > memmove and memcpy. The test expansion is mostly in the vein of
> > increasing the maximum size, increasing the number of unique
> > alignments tested, and testing both source < destination and vice
> > versa. The benchmark expansaion is just to increase the number of
> > unique alignments. test-memcpy, test-memccpy, test-mempcpy,
> > test-memmove, and tst-memmove-overflow all pass.
> >
> > Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com>
> > ---
> >  benchtests/bench-memcpy-large.c |  8 +++-
> >  string/test-memcpy.c            | 61 ++++++++++++++++------------
> >  string/test-memmove.c           | 70 ++++++++++++++++++++-------------
> >  3 files changed, 83 insertions(+), 56 deletions(-)
> >
> > diff --git a/benchtests/bench-memcpy-large.c b/benchtests/bench-memcpy-large.c
> > index 3df1575514..efb9627b1e 100644
> > --- a/benchtests/bench-memcpy-large.c
> > +++ b/benchtests/bench-memcpy-large.c
> > @@ -57,11 +57,11 @@ do_test (json_ctx_t *json_ctx, size_t align1, size_t align2, size_t len)
> >    size_t i, j;
> >    char *s1, *s2;
> >
> > -  align1 &= 63;
> > +  align1 &= 4095;
> >    if (align1 + len >= page_size)
> >      return;
> >
> > -  align2 &= 63;
> > +  align2 &= 4095;
> >    if (align2 + len >= page_size)
> >      return;
> >
> > @@ -113,6 +113,10 @@ test_main (void)
> >        do_test (&json_ctx, 0, 3, i + 15);
> >        do_test (&json_ctx, 3, 0, i + 31);
> >        do_test (&json_ctx, 3, 5, i + 63);
> > +      do_test (&json_ctx, 0, 127, i);
> > +      do_test (&json_ctx, 0, 255, i);
> > +      do_test (&json_ctx, 0, 256, i);
> > +      do_test (&json_ctx, 0, 4064, i);
> >      }
> >
> >    json_array_end (&json_ctx);
> > diff --git a/string/test-memcpy.c b/string/test-memcpy.c
> > index 2e9c6bd099..c9dfc88fed 100644
> > --- a/string/test-memcpy.c
> > +++ b/string/test-memcpy.c
> > @@ -82,11 +82,11 @@ do_test (size_t align1, size_t align2, size_t len)
> >    size_t i, j;
> >    char *s1, *s2;
> >
> > -  align1 &= 63;
> > +  align1 &= 4095;
> >    if (align1 + len >= page_size)
> >      return;
> >
> > -  align2 &= 63;
> > +  align2 &= 4095;
> >    if (align2 + len >= page_size)
> >      return;
> >
> > @@ -213,11 +213,9 @@ do_random_tests (void)
> >  }
> >
> >  static void
> > -do_test1 (void)
> > +do_test1 (size_t size)
> >  {
> > -  size_t size = 0x100000;
> >    void *large_buf;
> > -
> >    large_buf = mmap (NULL, size * 2 + page_size, PROT_READ | PROT_WRITE,
> >                     MAP_PRIVATE | MAP_ANON, -1, 0);
> >    if (large_buf == MAP_FAILED)
> > @@ -233,27 +231,32 @@ do_test1 (void)
> >    uint32_t *dest = large_buf;
> >    uint32_t *src = large_buf + size + page_size;
> >    size_t i;
> > -
> > -  for (i = 0; i < arrary_size; i++)
> > -    src[i] = (uint32_t) i;
> > -
> > -  FOR_EACH_IMPL (impl, 0)
> > +  size_t repeats;
> > +  for(repeats = 0; repeats < 2; repeats++)
> >      {
> > -      memset (dest, -1, size);
> > -      CALL (impl, (char *) dest, (char *) src, size);
> >        for (i = 0; i < arrary_size; i++)
> > -       if (dest[i] != src[i])
> > -         {
> > -           error (0, 0,
> > -                  "Wrong result in function %s dst \"%p\" src \"%p\" offset \"%zd\"",
> > -                  impl->name, dest, src, i);
> > -           ret = 1;
> > -           break;
> > -         }
> > +        src[i] = (uint32_t) i;
> > +
> > +      FOR_EACH_IMPL (impl, 0)
> > +        {
> > +            printf ("\t\tRunning: %s\n", impl->name);
> > +          memset (dest, -1, size);
> > +          CALL (impl, (char *) dest, (char *) src, size);
> > +          for (i = 0; i < arrary_size; i++)
> > +        if (dest[i] != src[i])
> > +          {
> > +            error (0, 0,
> > +               "Wrong result in function %s dst \"%p\" src \"%p\" offset \"%zd\"",
> > +               impl->name, dest, src, i);
> > +            ret = 1;
> > +            munmap ((void *) large_buf, size * 2 + page_size);
> > +            return;
> > +          }
> > +        }
> > +      dest = src;
> > +      src = large_buf;
> >      }
> > -
> > -  munmap ((void *) dest, size);
> > -  munmap ((void *) src, size);
> > +  munmap ((void *) large_buf, size * 2 + page_size);
> >  }
> >
> >  int
> > @@ -275,7 +278,6 @@ test_main (void)
> >        do_test (0, i, 1 << i);
> >        do_test (i, i, 1 << i);
> >      }
> > -
> >    for (i = 0; i < 32; ++i)
> >      {
> >        do_test (0, 0, i);
> > @@ -294,12 +296,19 @@ test_main (void)
> >        do_test (i, i, 16 * i);
> >      }
> >
> > +  for (i = 19; i <= 25; ++i)
> > +    {
> > +      do_test (255, 0, 1 << i);
> > +      do_test (0, 255, i);
> > +      do_test (0, 4000, i);
> > +    }
> > +
> >    do_test (0, 0, getpagesize ());
> >
> >    do_random_tests ();
> >
> > -  do_test1 ();
> > -
> > +  do_test1 (0x100000);
> > +  do_test1 (0x2000000);
> >    return ret;
> >  }
> >
> > diff --git a/string/test-memmove.c b/string/test-memmove.c
> > index 2e3ce75b9b..ff8099d12f 100644
> > --- a/string/test-memmove.c
> > +++ b/string/test-memmove.c
> > @@ -247,7 +247,7 @@ do_random_tests (void)
> >  }
> >
> >  static void
> > -do_test2 (void)
> > +do_test2 (size_t offset)
> >  {
> >    size_t size = 0x20000000;
> >    uint32_t * large_buf;
> > @@ -268,33 +268,45 @@ do_test2 (void)
> >      }
> >
> >    size_t bytes_move = 0x80000000 - (uintptr_t) large_buf;
> > +  if (bytes_move + offset * sizeof (uint32_t) > size)
> > +    {
> > +      munmap ((void *) large_buf, size);
> > +      return;
> > +    }
> >    size_t arr_size = bytes_move / sizeof (uint32_t);
> >    size_t i;
> > -
> > -  FOR_EACH_IMPL (impl, 0)
> > -    {
> > -      for (i = 0; i < arr_size; i++)
> > -        large_buf[i] = (uint32_t) i;
> > -
> > -      uint32_t * dst = &large_buf[33];
> > -
> > -#ifdef TEST_BCOPY
> > -      CALL (impl, (char *) large_buf, (char *) dst, bytes_move);
> > -#else
> > -      CALL (impl, (char *) dst, (char *) large_buf, bytes_move);
> > -#endif
> > -
> > -      for (i = 0; i < arr_size; i++)
> > -       {
> > -         if (dst[i] != (uint32_t) i)
> > -           {
> > -             error (0, 0,
> > -                    "Wrong result in function %s dst \"%p\" src \"%p\" offset \"%zd\"",
> > -                    impl->name, dst, large_buf, i);
> > -             ret = 1;
> > -             break;
> > -           }
> > -       }
> > +  size_t repeats;
> > +  uint32_t * src = large_buf;
> > +  uint32_t * dst = &large_buf[offset];
> > +  for (repeats = 0; repeats < 2; ++repeats)
> > +    {
>             ^  Trailing whitespaces.

fixed.
>
> > +      FOR_EACH_IMPL (impl, 0)
> > +        {
> > +          for (i = 0; i < arr_size; i++)
> > +            src[i] = (uint32_t) i;
> > +
> > +
> > +    #ifdef TEST_BCOPY
> > +          CALL (impl, (char *) src, (char *) dst, bytes_move);
> > +    #else
> > +          CALL (impl, (char *) dst, (char *) src, bytes_move);
> > +    #endif
> > +
> > +          for (i = 0; i < arr_size; i++)
> > +        {
> > +          if (dst[i] != (uint32_t) i)
> > +            {
> > +              error (0, 0,
> > +                 "Wrong result in function %s dst \"%p\" src \"%p\" offset \"%zd\"",
> > +                 impl->name, dst, large_buf, i);
> > +              ret = 1;
> > +              munmap ((void *) large_buf, size);
> > +              return;
> > +            }
> > +        }
> > +        }
> > +      src = dst;
> > +      dst = large_buf;
> >      }
> >
> >    munmap ((void *) large_buf, size);
> > @@ -340,8 +352,10 @@ test_main (void)
> >
> >    do_random_tests ();
> >
> > -  do_test2 ();
> > -
> > +  do_test2 (33);
> > +  do_test2 (0x200000);
> > +  do_test2 (0x4000000 - 1);
> > +  do_test2 (0x4000000);
> >    return ret;
> >  }
> >
> > --
> > 2.29.2
> >
>
>
> --
> H.J.
diff mbox series

Patch

diff --git a/benchtests/bench-memcpy-large.c b/benchtests/bench-memcpy-large.c
index 3df1575514..efb9627b1e 100644
--- a/benchtests/bench-memcpy-large.c
+++ b/benchtests/bench-memcpy-large.c
@@ -57,11 +57,11 @@  do_test (json_ctx_t *json_ctx, size_t align1, size_t align2, size_t len)
   size_t i, j;
   char *s1, *s2;
 
-  align1 &= 63;
+  align1 &= 4095;
   if (align1 + len >= page_size)
     return;
 
-  align2 &= 63;
+  align2 &= 4095;
   if (align2 + len >= page_size)
     return;
 
@@ -113,6 +113,10 @@  test_main (void)
       do_test (&json_ctx, 0, 3, i + 15);
       do_test (&json_ctx, 3, 0, i + 31);
       do_test (&json_ctx, 3, 5, i + 63);
+      do_test (&json_ctx, 0, 127, i);
+      do_test (&json_ctx, 0, 255, i);
+      do_test (&json_ctx, 0, 256, i);
+      do_test (&json_ctx, 0, 4064, i);
     }
 
   json_array_end (&json_ctx);
diff --git a/string/test-memcpy.c b/string/test-memcpy.c
index 2e9c6bd099..c9dfc88fed 100644
--- a/string/test-memcpy.c
+++ b/string/test-memcpy.c
@@ -82,11 +82,11 @@  do_test (size_t align1, size_t align2, size_t len)
   size_t i, j;
   char *s1, *s2;
 
-  align1 &= 63;
+  align1 &= 4095;
   if (align1 + len >= page_size)
     return;
 
-  align2 &= 63;
+  align2 &= 4095;
   if (align2 + len >= page_size)
     return;
 
@@ -213,11 +213,9 @@  do_random_tests (void)
 }
 
 static void
-do_test1 (void)
+do_test1 (size_t size)
 {
-  size_t size = 0x100000;
   void *large_buf;
-
   large_buf = mmap (NULL, size * 2 + page_size, PROT_READ | PROT_WRITE,
 		    MAP_PRIVATE | MAP_ANON, -1, 0);
   if (large_buf == MAP_FAILED)
@@ -233,27 +231,32 @@  do_test1 (void)
   uint32_t *dest = large_buf;
   uint32_t *src = large_buf + size + page_size;
   size_t i;
-
-  for (i = 0; i < arrary_size; i++)
-    src[i] = (uint32_t) i;
-
-  FOR_EACH_IMPL (impl, 0)
+  size_t repeats;
+  for(repeats = 0; repeats < 2; repeats++)
     {
-      memset (dest, -1, size);
-      CALL (impl, (char *) dest, (char *) src, size);
       for (i = 0; i < arrary_size; i++)
-	if (dest[i] != src[i])
-	  {
-	    error (0, 0,
-		   "Wrong result in function %s dst \"%p\" src \"%p\" offset \"%zd\"",
-		   impl->name, dest, src, i);
-	    ret = 1;
-	    break;
-	  }
+        src[i] = (uint32_t) i;
+
+      FOR_EACH_IMPL (impl, 0)
+        {
+            printf ("\t\tRunning: %s\n", impl->name);
+          memset (dest, -1, size);
+          CALL (impl, (char *) dest, (char *) src, size);
+          for (i = 0; i < arrary_size; i++)
+        if (dest[i] != src[i])
+          {
+            error (0, 0,
+               "Wrong result in function %s dst \"%p\" src \"%p\" offset \"%zd\"",
+               impl->name, dest, src, i);
+            ret = 1;
+            munmap ((void *) large_buf, size * 2 + page_size);
+            return;
+          }
+        }
+      dest = src;
+      src = large_buf;
     }
-
-  munmap ((void *) dest, size);
-  munmap ((void *) src, size);
+  munmap ((void *) large_buf, size * 2 + page_size);
 }
 
 int
@@ -275,7 +278,6 @@  test_main (void)
       do_test (0, i, 1 << i);
       do_test (i, i, 1 << i);
     }
-
   for (i = 0; i < 32; ++i)
     {
       do_test (0, 0, i);
@@ -294,12 +296,19 @@  test_main (void)
       do_test (i, i, 16 * i);
     }
 
+  for (i = 19; i <= 25; ++i)
+    {
+      do_test (255, 0, 1 << i);
+      do_test (0, 255, i);
+      do_test (0, 4000, i);
+    }
+
   do_test (0, 0, getpagesize ());
 
   do_random_tests ();
 
-  do_test1 ();
-
+  do_test1 (0x100000);
+  do_test1 (0x2000000);
   return ret;
 }
 
diff --git a/string/test-memmove.c b/string/test-memmove.c
index 2e3ce75b9b..ff8099d12f 100644
--- a/string/test-memmove.c
+++ b/string/test-memmove.c
@@ -247,7 +247,7 @@  do_random_tests (void)
 }
 
 static void
-do_test2 (void)
+do_test2 (size_t offset)
 {
   size_t size = 0x20000000;
   uint32_t * large_buf;
@@ -268,33 +268,45 @@  do_test2 (void)
     }
 
   size_t bytes_move = 0x80000000 - (uintptr_t) large_buf;
+  if (bytes_move + offset * sizeof (uint32_t) > size)
+    {
+      munmap ((void *) large_buf, size);
+      return;
+    }
   size_t arr_size = bytes_move / sizeof (uint32_t);
   size_t i;
-
-  FOR_EACH_IMPL (impl, 0)
-    {
-      for (i = 0; i < arr_size; i++)
-        large_buf[i] = (uint32_t) i;
-
-      uint32_t * dst = &large_buf[33];
-
-#ifdef TEST_BCOPY
-      CALL (impl, (char *) large_buf, (char *) dst, bytes_move);
-#else
-      CALL (impl, (char *) dst, (char *) large_buf, bytes_move);
-#endif
-
-      for (i = 0; i < arr_size; i++)
-	{
-	  if (dst[i] != (uint32_t) i)
-	    {
-	      error (0, 0,
-		     "Wrong result in function %s dst \"%p\" src \"%p\" offset \"%zd\"",
-		     impl->name, dst, large_buf, i);
-	      ret = 1;
-	      break;
-	    }
-	}
+  size_t repeats;
+  uint32_t * src = large_buf;
+  uint32_t * dst = &large_buf[offset];
+  for (repeats = 0; repeats < 2; ++repeats)
+    {      
+      FOR_EACH_IMPL (impl, 0)
+        {
+          for (i = 0; i < arr_size; i++)
+            src[i] = (uint32_t) i;
+
+
+    #ifdef TEST_BCOPY
+          CALL (impl, (char *) src, (char *) dst, bytes_move);
+    #else
+          CALL (impl, (char *) dst, (char *) src, bytes_move);
+    #endif
+
+          for (i = 0; i < arr_size; i++)
+        {
+          if (dst[i] != (uint32_t) i)
+            {
+              error (0, 0,
+                 "Wrong result in function %s dst \"%p\" src \"%p\" offset \"%zd\"",
+                 impl->name, dst, large_buf, i);
+              ret = 1;
+              munmap ((void *) large_buf, size);
+              return;
+            }
+        }
+        }
+      src = dst;
+      dst = large_buf;
     }
 
   munmap ((void *) large_buf, size);
@@ -340,8 +352,10 @@  test_main (void)
 
   do_random_tests ();
 
-  do_test2 ();
-
+  do_test2 (33);
+  do_test2 (0x200000);
+  do_test2 (0x4000000 - 1);
+  do_test2 (0x4000000);
   return ret;
 }