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From: "pault at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug fortran/40598]  New: Some missed optimizations in array assignment
Date: Tue, 30 Jun 2009 07:53:00 -0000	[thread overview]
Message-ID: <bug-40598-10374@http.gcc.gnu.org/bugzilla/> (raw)

The fix for PR40551 made me realise that there are some assignment
optimizations that are missed:

  integer :: array (3, 3), source (3, 3)
  array = 0
  array(:, 1) = 0             ! could use __builtin_memcpy
  array(1,:) = 0
  source = array              ! uses __builtin_memcpy
  source(:,1) = array (:,2)   ! could use __builtin_memcpy
  source(1,:) = array (2,:)
  source = reshape ([1,2,3,4,5,6,7,8,9],[3,3]) ! uses __builtin_memcpy
  array(:,1) = [1,2,3]        ! could use __builtin_memcpy
end


At present, there is only a test that the lhs array is full.  Any contiguous
reference could take these opportunities too.  Some work will be required with
the helper functions but this is not a big deal.

I'll take it on.

Paul


-- 
           Summary: Some missed optimizations in array assignment
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: pault at gcc dot gnu dot org
        ReportedBy: pault at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40598


             reply	other threads:[~2009-06-30  7:53 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-06-30  7:53 pault at gcc dot gnu dot org [this message]
2009-06-30  9:40 ` [Bug fortran/40598] " rguenth at gcc dot gnu dot org
2009-06-30  9:47 ` burnus at gcc dot gnu dot org
2009-06-30  9:55 ` pault at gcc dot gnu dot org
2009-06-30 12:57 ` pault at gcc dot gnu dot org
2009-07-01  7:52 ` burnus at gcc dot gnu dot org
2009-07-01  8:23 ` pault at gcc dot gnu dot org
2009-07-01  9:43 ` rguenth at gcc dot gnu dot org
2009-07-01 10:51 ` pault at gcc dot gnu dot org
2009-07-01 11:02 ` pault at gcc dot gnu dot org
2010-05-07 21:02 ` dfranke at gcc dot gnu dot org
2010-05-08 12:57 ` pault at gcc dot gnu dot org
2010-05-08 20:58 ` dfranke at gcc dot gnu dot org

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