public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
* [Bug middle-end/49969] New: not vectorized: data ref analysis failed
@ 2011-08-03 17:24 burnus at gcc dot gnu.org
  2011-08-04  9:45 ` [Bug middle-end/49969] " rguenth at gcc dot gnu.org
  2012-07-13  8:35 ` rguenth at gcc dot gnu.org
  0 siblings, 2 replies; 3+ messages in thread
From: burnus at gcc dot gnu.org @ 2011-08-03 17:24 UTC (permalink / raw)
  To: gcc-bugs

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49969

           Summary: not vectorized: data ref analysis failed
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: normal
          Priority: P3
         Component: middle-end
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: burnus@gcc.gnu.org
                CC: irar@gcc.gnu.org, rguenther@suse.de


The following program does not vectorize. With Intel's ifort one gets the
message:

  PERMUTED LOOP WAS VECTORIZED

while GCC just prints:

test.f90:6: note: not vectorized: data ref analysis failed D.1566_33 =
*iz_32(D)[D.1565_31];

test.f90:7: note: not vectorized: data ref analysis failed D.1566_33 =
*iz_32(D)[D.1565_31];

test.f90:2: note: vectorized 0 loops in function.


In case of GCC, it does not depend on the loop order - permuting does not
change anything. Also it is independent of the patch to PR 49957.


! From Polyhedron's ac.f90, line 746
      SUBROUTINE SUSCEP(L,Iz,Dsus)
      INTEGER L , Iz(L,L) , iznum
      DOUBLE PRECISION Dsus
      iznum = 0
      DO iy = 1 , L
        DO ix = 1 , L
          iznum = iznum + Iz(iy,ix)
        ENDDO
      ENDDO
      Dsus = DBLE(iznum)
      Dsus = Dsus*Dsus
      Dsus = Dsus/(L*L)
      END


^ permalink raw reply	[flat|nested] 3+ messages in thread
* [Bug middle-end/49969] not vectorized: data ref analysis failed
  2011-08-03 17:24 [Bug middle-end/49969] New: not vectorized: data ref analysis failed burnus at gcc dot gnu.org
@ 2011-08-04  9:45 ` rguenth at gcc dot gnu.org
  2012-07-13  8:35 ` rguenth at gcc dot gnu.org
  1 sibling, 0 replies; 3+ messages in thread
From: rguenth at gcc dot gnu.org @ 2011-08-04  9:45 UTC (permalink / raw)
  To: gcc-bugs

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49969

Richard Guenther <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2011.08.04 09:44:45
                 CC|                            |spop at gcc dot gnu.org
     Ever Confirmed|0                           |1

--- Comment #1 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-08-04 09:44:45 UTC ---
Well, that's because the evolution of D.1565_31 is

{{(stride.2_11 + offset.3_21) + 1, +, 1}_1, +, stride.2_11}_2

the loop needs interchange to be vectorized, but that doesn't work either
(no idea for the reason - the .graphite dump isn't very informative here,
well, maybe it runs into the exactly same issue and already gives up?)

Sebastian?

Confirmed anyway.  Supposed to be vectorized with -floop-interchange.


^ permalink raw reply	[flat|nested] 3+ messages in thread
* [Bug middle-end/49969] not vectorized: data ref analysis failed
  2011-08-03 17:24 [Bug middle-end/49969] New: not vectorized: data ref analysis failed burnus at gcc dot gnu.org
  2011-08-04  9:45 ` [Bug middle-end/49969] " rguenth at gcc dot gnu.org
@ 2012-07-13  8:35 ` rguenth at gcc dot gnu.org
  1 sibling, 0 replies; 3+ messages in thread
From: rguenth at gcc dot gnu.org @ 2012-07-13  8:35 UTC (permalink / raw)
  To: gcc-bugs

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49969

Richard Guenther <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Blocks|                            |53947

--- Comment #2 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-07-13 08:34:49 UTC ---
Link to vectorizer missed-optimization meta-bug.


^ permalink raw reply	[flat|nested] 3+ messages in thread
end of thread, other threads:[~2012-07-13  8:35 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2011-08-03 17:24 [Bug middle-end/49969] New: not vectorized: data ref analysis failed burnus at gcc dot gnu.org
2011-08-04  9:45 ` [Bug middle-end/49969] " rguenth at gcc dot gnu.org
2012-07-13  8:35 ` rguenth at gcc dot gnu.org

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).