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Date: Mon, 15 Nov 2004 05:36:00 -0000
From: "paulthomas2 at wanadoo dot fr" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Message-ID: <20041115053618.18495.paulthomas2@wanadoo.fr>
Reply-To: gcc-bugzilla@gcc.gnu.org
Subject: [Bug fortran/18495] New: Intrinisc function SPREAD is broken
X-Bugzilla-Reason: CC
X-SW-Source: 2004-11/txt/msg01830.txt.bz2
List-Id: <gcc-bugs.sourceware.org>

Detected a fault in the fortran 90 version of the LLNL "mflops" test.  SPREAD 
is causing a segmentation fault in "KERNEL 21". Replacing this section with 
the fortran77 kernel corrects the fault (BTW will report the benchmarks on the 
gfortran wiki - they do not look too bad at all!).  The fault is caused by:

      DO K = 1, 25
           PX(:,:N) = PX(:,:N) + SPREAD(VY(:25,K),DIM = 2,NCOPIES = N)* &
     &          SPREAD(CX(K,:N),DIM = 1,NCOPIES = 25)
      END DO

where N is 1000

The following codelet gives incorrect results for small N and also segment 
faults for large enough N (eg 1000, as here):

program test_spread
   implicit none
   integer, parameter :: N = 1000
   integer            :: I
   integer, dimension(N) :: source 
   integer, dimension(N,N) :: sink
   do i = 1 , N
      source(i) = N
   end do
   print *,'product'
   sink = spread( source , 1 , N ) * spread( source , N , N )
   print *, sink
   stop
end program test_spread

-- 
           Summary: Intrinisc function SPREAD is broken
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: paulthomas2 at wanadoo dot fr
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18495