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

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

[dominiq at lps dot ens.fr]

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

             Bug #: 50435
           Summary: FAIL: gcc.dg/vect/bb-slp-25.c (-flto)?
                    scan-tree-dump-times slp "basic block vectorized using
                    SLP" 1
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: testsuite
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: dominiq@lps.ens.fr
                CC: irar@gcc.gnu.org
              Host: x86_64-apple-darwin10
            Target: x86_64-apple-darwin10
             Build: x86_64-apple-darwin10


On x86_64-apple-darwin10 the test gcc.dg/vect/bb-slp-25.c fails (see
http://gcc.gnu.org/ml/gcc-testresults/2011-09/msg01560.html ). Looking for SLP
in bb-slp-25.c.115t.slp I get

189: Failed to SLP the basic block.
189: not vectorized: failed to find SLP opportunities in basic block.
18: Failed to SLP the basic block.
18: not vectorized: failed to find SLP opportunities in basic block.
41: Failed to SLP the basic block.
41: not vectorized: failed to find SLP opportunities in basic block.
48: Failed to SLP the basic block.
48: not vectorized: failed to find SLP opportunities in basic block.

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 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.

[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]

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

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

[dominiq at lps dot ens.fr]

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

--- Comment #2 from Dominique d'Humieres <dominiq at lps dot ens.fr> 2011-09-16 15:53:07 UTC ---
> I understand that the loop vectorization somehow worked, so could you please
> try the following patch to avoid it:

Sorry, but after the patch I still have

Running /opt/gcc/work/gcc/testsuite/gcc.dg/vect/vect.exp ...
FAIL: gcc.dg/vect/bb-slp-25.c scan-tree-dump-times slp "basic block vectorized
using SLP" 1
FAIL: gcc.dg/vect/bb-slp-25.c -flto scan-tree-dump-times slp "basic block
vectorized using SLP" 1

        === gcc Summary for unix/-m32 ===

# of expected passes        4
# of unexpected failures    2
Running target unix/-m64
...
Running /opt/gcc/work/gcc/testsuite/gcc.dg/vect/vect.exp ...
FAIL: gcc.dg/vect/bb-slp-25.c scan-tree-dump-times slp "basic block vectorized
using SLP" 1
FAIL: gcc.dg/vect/bb-slp-25.c -flto scan-tree-dump-times slp "basic block
vectorized using SLP" 1

        === gcc Summary for unix/-m64 ===

# of expected passes        4
# of unexpected failures    2

        === gcc Summary ===

# of expected passes        8
# of unexpected failures    4
/opt/gcc/build_w/gcc/xgcc  version 4.7.0 20110916 (experimental) [trunk
revision 178905] (GCC) 

The loop is not vectorized:

/opt/gcc/work/gcc/testsuite/gcc.dg/vect/bb-slp-25.c:12: note: vectorized 0
loops in function.

and looking for SLP yields

189: Failed to SLP the basic block.
189: not vectorized: failed to find SLP opportunities in basic block.
43: Failed to SLP the basic block.
43: not vectorized: failed to find SLP opportunities in basic block.
50: Failed to SLP the basic block.
50: not vectorized: failed to find SLP opportunities in basic block.

[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]

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

--- Comment #3 from Ira Rosen <irar at il dot ibm.com> 2011-09-16 16:18:37 UTC ---
Well, at least the loop is not vectorized now :).
Could you please attach the slp dump (-fdump-tree-slp-details)?

Thanks,
Ira

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

[dominiq at lps dot ens.fr]

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

--- Comment #4 from Dominique d'Humieres <dominiq at lps dot ens.fr> 2011-09-16 17:37:17 UTC ---
Created attachment 25307
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=25307
slp dump attached

[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]

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

--- Comment #5 from Ira Rosen <irar at il dot ibm.com> 2011-09-18 08:52:56 UTC ---
Thanks.

Data dependence analysis can't determine dependence between src and dst
although they have _restrict_, and it works fine on x86_64-suse-linux for
example... Does darwin have a known problem with restrict?

Thanks,
Ira

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

[dominiq at lps dot ens.fr]

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

--- Comment #6 from Dominique d'Humieres <dominiq at lps dot ens.fr> 2011-09-18 10:41:09 UTC ---
> Does darwin have a known problem with restrict?

None I am aware of. BTW what is the difference between '*__restrict__'  and '*
__restrict' (or '* __restrict__')?

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

[dominiq at lps dot ens.fr]

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

--- Comment #7 from Dominique d'Humieres <dominiq at lps dot ens.fr> 2011-09-18 10:45:08 UTC ---
Note that the test succeeds if I replace '* __restrict' with '*__restrict__'

[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]

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

--- Comment #8 from Ira Rosen <irar at il dot ibm.com> 2011-09-18 10:48:43 UTC ---
Looks like there is a difference ;)
I guess it succeeds with the patch to avoid loop vectorization and the fix of
restrict together?

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

[dominiq at lps dot ens.fr]

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

--- Comment #9 from Dominique d'Humieres <dominiq at lps dot ens.fr> 2011-09-18 10:54:14 UTC ---
> Looks like there is a difference ;)
> I guess it succeeds with the patch to avoid loop vectorization and the fix of restrict together?

Here is the patched test that gives no failure (i.e., yours and the change to
restrict):

--- ../_clean/gcc/testsuite/gcc.dg/vect/bb-slp-25.c    2011-09-15
13:34:18.000000000 +0200
+++ gcc/testsuite/gcc.dg/vect/bb-slp-25.c    2011-09-18 12:42:21.000000000
+0200
@@ -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++)
     {

[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]

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

--- Comment #10 from Ira Rosen <irar at il dot ibm.com> 2011-09-18 10:55:19 UTC ---
Thanks, I'll commit it.

[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 gcc dot gnu.org]

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

--- Comment #11 from irar at gcc dot gnu.org 2011-09-18 11:41:48 UTC ---
Author: irar
Date: Sun Sep 18 11:41:43 2011
New Revision: 178942

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=178942
Log:

    PR testsuite/50435
    * gcc.dg/vect/bb-slp-25.c: Add an if to avoid loop vectorization.
    Fix underscores around restrict.


Modified:
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gcc.dg/vect/bb-slp-25.c

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

[dominiq at lps dot ens.fr]

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

--- Comment #12 from Dominique d'Humieres <dominiq at lps dot ens.fr> 2011-09-18 13:11:59 UTC ---
> Thanks, I'll commit it.

Thanks for the quick fix. I'ld like to leave this pr open until someone figure
out what's wrong with darwin and __restrict. 

Note that I have replaced all the occurrences of __restrict with __restrict__ 
I have found in gcc.dg/vect/* and bb-slp-25.c is the only test for which it
mattered.

[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]

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

--- Comment #13 from Ira Rosen <irar at il dot ibm.com> 2011-09-19 08:59:44 UTC ---
(In reply to comment #12)

> Note that I have replaced all the occurrences of __restrict with __restrict__ 
> I have found in gcc.dg/vect/* and bb-slp-25.c is the only test for which it
> mattered.

It is probably just doesn't matter in other tests: we can use versioning for
alias in loop vectorization.

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

[dominiq at lps dot ens.fr]

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

Dominique d'Humieres <dominiq at lps dot ens.fr> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |FIXED

--- Comment #14 from Dominique d'Humieres <dominiq at lps dot ens.fr> 2012-01-12 17:06:53 UTC ---
Closing as fixed.