[Bug testsuite/50435] FAIL: gcc.dg/vect/bb-slp-25.c (-flto)? scan-tree-dump-times slp "basic block vectorized using SLP" 1

["irar at il dot ibm.com" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50435

Ira Rosen <irar at il dot ibm.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |irar at il dot ibm.com

--- Comment #1 from Ira Rosen <irar at il dot ibm.com> 2011-09-16 15:18:11 UTC ---
(In reply to comment #0)
> 
> indeed no "basic block vectorized using SLP". However compiling the test with
> -ftree-vectorizer-verbose=2 returns
> 
> ...
> Vectorizing loop at /opt/gcc/work/gcc/testsuite/gcc.dg/vect/bb-slp-25.c:16
> 
> 16: created 2 versioning for alias checks.
> 
> 16: vectorizing stmts using SLP.
> 16: LOOP VECTORIZED.
> ...

I understand that the loop vectorization somehow worked, so could you please
try the following patch to avoid it:

Index: bb-slp-25.c
===================================================================
--- bb-slp-25.c (revision 178880)
+++ bb-slp-25.c (working copy)
@@ -9,7 +9,7 @@

 short src[N], dst[N];

-void foo (short * __restrict dst, short * __restrict src, int h, int stride)
+void foo (short * __restrict dst, short * __restrict src, int h, int stride,
int dummy)
 {
   int i;
   h /= 16;
@@ -25,6 +25,8 @@ void foo (short * __restrict dst, short
       dst[7] += A*src[7] + src[7+stride];
       dst += 8;
       src += 8;
+      if (dummy == 32)
+        abort ();
    }
 }

@@ -41,7 +43,7 @@ int main (void)
        src[i] = i;
     }

-  foo (dst, src, N, 8);
+  foo (dst, src, N, 8, 0);

   for (i = 0; i < N/2; i++)
     {


> 
> I have applied r178880 on top of r178869 on powerpc-apple-darwin9 and the tests
> pass while I get the above results when I run them manually.

For PowerPC vect_element_align is false, while

/* { dg-final { scan-tree-dump-times "basic block vectorized using SLP" 1 "slp"
{ target vect_element_align } } } */

so we don't expect the basic block to get vectorized.

Thanks,
Ira