[Bug tree-optimization/41957] New: [4.4/4.5 Regression] ICE with -ftree-loop-linear

[Bug tree-optimization/41957] New: [4.4/4.5 Regression] ICE with -ftree-loop-linear

[tkoenig at gcc dot gnu dot org]

$ cat > gugu.f

c AtAMul: Left-multiplies matrix AMat by its transpose ----------------
c         AtAMat = transpose(AMat) * AMat
c          k,k               k,n     n,k
c     the resultant matrix AtAMat is returned in lower triangle form
c ---------------------------------------------------------------------
      Subroutine AtAmul(AMat,AtAMat,kDim,nDim)
      IMPLICIT NONE

c   Input:                   Output:                   Local:
      Integer      kDim,nDim,                            i, j, ij, n
      Real*8  AMat(kDim,nDim), AtAMat(kDim*(kDim+1)/2),  Ai1, Ain

c     initialization loop n=1 :
      ij = 0
      do i = 1, kDim
        Ai1 = AMat(i,1)
        do j = 1, i-1
          AtAMat(ij+j) = Ai1 * AMat(j,1)
        enddo
        ij = ij + i
        AtAMat(ij) = Ai1 * Ai1
      enddo

c     accumulation loop n=2,nDim :
      do n = 2, nDim
        ij = 0
        do i = 1, kDim
          Ain = AMat(i,n)
          do j = 1, i-1
            AtAMat(ij+j) = AtAMat(ij+j) + Ain * AMat(j,n)
          enddo
          ij = ij + i
          AtAMat(ij) = AtAMat(ij) + Ain * Ain
        enddo
      enddo

      end
 gfortran -O3 -ftree-loop-linear gugu.f
gugu.f: In function 'atamul_':
gugu.f:6:0: internal compiler error: in initialize_matrix_A, at
tree-data-ref.c:1912
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.
$ gfortran-4.4 -O3 -ftree-loop-linear gugu.f
gugu.f: In function 'atamul':
gugu.f:6: internal compiler error: in initialize_matrix_A, at
tree-data-ref.c:1880
Please submit a full bug report,
with preprocessed source if appropriate.
See <file:///usr/share/doc/gcc-4.4/README.Bugs> for instructions.
$ gfortran-4.3 -O3 -ftree-loop-linear gugu.f
/usr/lib/gcc/i486-linux-gnu/4.3.4/libgfortranbegin.a(fmain.o): In function
`main':
(.text+0x35): undefined reference to `MAIN__'
collect2: ld returned 1 exit status


-- 
           Summary: [4.4/4.5 Regression] ICE with -ftree-loop-linear
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: tkoenig at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41957

[Bug tree-optimization/41957] [4.4/4.5 Regression] ICE with -ftree-loop-linear

[tkoenig at gcc dot gnu dot org]

-- 

tkoenig at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.5.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41957

[Bug tree-optimization/41957] [4.4/4.5 Regression] ICE with -ftree-loop-linear

[pinskia at gcc dot gnu dot org]

------- Comment #1 from pinskia at gcc dot gnu dot org  2009-11-05 20:57 -------
This is most likely related to PR 40281.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41957

[Bug tree-optimization/41957] [4.4/4.5 Regression] ICE with -ftree-loop-linear in initialize_matrix_A, at tree-data-ref.c:1912

[burnus at gcc dot gnu dot org]

------- Comment #2 from burnus at gcc dot gnu dot org  2009-11-05 20:59 -------
Fails on x86-64-linux with
   gfortran -m32 -O1 -ftree-loop-linear
but works with -m64.


-- 

burnus at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |burnus at net-b dot de
 GCC target triplet|                            |x86*-unknown-linux-gnu
      Known to fail|                            |4.4.2 4.5.0
      Known to work|                            |4.3.4
            Summary|[4.4/4.5 Regression] ICE    |[4.4/4.5 Regression] ICE
                   |with -ftree-loop-linear     |with -ftree-loop-linear  in
                   |                            |initialize_matrix_A, at
                   |                            |tree-data-ref.c:1912
   Target Milestone|4.5.0                       |4.4.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41957

[Bug tree-optimization/41957] [4.4/4.5 Regression] ICE with -ftree-loop-linear in initialize_matrix_A, at tree-data-ref.c:1912

[burnus at gcc dot gnu dot org]

------- Comment #3 from burnus at gcc dot gnu dot org  2009-11-05 21:00 -------
First reported by Hans Horn at
http://gcc.gnu.org/ml/fortran/2009-11/msg00084.html


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41957

[Bug tree-optimization/41957] [4.4/4.5 Regression] ICE with -ftree-loop-linear in initialize_matrix_A, at tree-data-ref.c:1912

[rguenth at gcc dot gnu dot org]

-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41957

[Bug tree-optimization/41957] [4.4/4.5 Regression] ICE with -ftree-loop-linear in initialize_matrix_A, at tree-data-ref.c:1912

[rguenth at gcc dot gnu dot org]

------- Comment #4 from rguenth at gcc dot gnu dot org  2009-11-09 13:59 -------
Indeed.  Same symptoms at least:

(gdb) call debug_generic_expr (chrec)
{0, +, {2, +, 1}_4}_4

This one fails for me with -m32 only though.

The chrec isn't quite {2, +, 1}_4 - I think the IV evolves as 0, 3, 4, 5, 6,
...
if I parse it correctly.  That looks more like a loop like

  for (i=0;; ++i)
    for (j=i+3;; ++j)
      ...

where we somehow cleverly analyze this as a single loop... (?).

Sebastian - please have a look here and/or at PR40281.

*** This bug has been marked as a duplicate of 40281 ***


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
 GCC target triplet|x86*-unknown-linux-gnu      |i?86-unknown-linux-gnu
         Resolution|                            |DUPLICATE


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41957