[Bug fortran/47574] New: internal compiler error: in build2_stat, at tree.c:3795

[Bug fortran/47574] New: internal compiler error: in build2_stat, at tree.c:3795

[mlosch@uni-bremen.de]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47574

           Summary: internal compiler error: in build2_stat, at
                    tree.c:3795
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: mlosch@uni-bremen.de


Created attachment 23200
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=23200
example fortran code to reproduce bug

This appears to be a problem with optimization: with -O2 routine compiles
without errors. Small changes to the code also seems to fix the problem: e.g.
changing exchWidthX to OLx in line 947
The code is part of a ocean model used in oceanography (http://mitgcm.org) and
usually compiles on unix-like platforms with a f77 compiler without problems.

command-line and output follows, fortran code is attached:
gfortran -v -save-temps -Wunused -Wuninitialized -fsecond-underscore
-fconvert=big-endian -ffixed-line-length-132 -O3 -funroll-loops -c
exch2_uv_agrid_3d_rl.f
Using built-in specs.
COLLECT_GCC=gfortran
COLLECT_LTO_WRAPPER=/usr/local/libexec/gcc/x86_64-apple-darwin10.4.0/4.6.0/lto-wrapper
Target: x86_64-apple-darwin10.4.0
Configured with: ../gcc-4.6-20101106/configure --enable-languages=c++,fortran
Thread model: posix
gcc version 4.6.0 20101106 (experimental) (GCC) 
COLLECT_GCC_OPTIONS='-mmacosx-version-min=10.6.6' '-v' '-save-temps' '-Wunused'
'-Wuninitialized' '-fsecond-underscore' '-fconvert=big-endian'
'-ffixed-line-length-132' '-O3' '-funroll-loops' '-c' '-mtune=generic'
 /usr/local/libexec/gcc/x86_64-apple-darwin10.4.0/4.6.0/f951
exch2_uv_agrid_3d_rl.f -ffixed-form -fPIC -quiet -dumpbase
exch2_uv_agrid_3d_rl.f -mmacosx-version-min=10.6.6 -mtune=generic -auxbase
exch2_uv_agrid_3d_rl -O3 -Wunused -Wuninitialized -version -fsecond-underscore
-fconvert=big-endian -ffixed-line-length-132 -funroll-loops
-fintrinsic-modules-path
/usr/local/lib/gcc/x86_64-apple-darwin10.4.0/4.6.0/finclude -o
exch2_uv_agrid_3d_rl.s
GNU Fortran (GCC) version 4.6.0 20101106 (experimental)
(x86_64-apple-darwin10.4.0)
    compiled by GNU C version 4.6.0 20101106 (experimental), GMP version 4.3.1,
MPFR version 2.4.1, MPC version 0.8.1
GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
GNU Fortran (GCC) version 4.6.0 20101106 (experimental)
(x86_64-apple-darwin10.4.0)
    compiled by GNU C version 4.6.0 20101106 (experimental), GMP version 4.3.1,
MPFR version 2.4.1, MPC version 0.8.1
GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
exch2_uv_agrid_3d_rl.f: In function ‘exch2_uv_agrid_3d_rl’:
exch2_uv_agrid_3d_rl.f:293:0: internal compiler error: in build2_stat, at
tree.c:3795
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.

[Bug fortran/47574] internal compiler error: in build2_stat, at tree.c:3795

[mlosch@uni-bremen.de]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47574

Martin Losch <mlosch@uni-bremen.de> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
  Attachment #23200|0                           |1
        is obsolete|                            |

--- Comment #1 from Martin Losch <mlosch@uni-bremen.de> 2011-02-01 16:20:19 UTC ---
Created attachment 23201
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=23201
correct fortran code to reproduce problem

I am sorry for attaching the wrong file

[Bug fortran/47574] internal compiler error: in build2_stat, at tree.c:3795

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47574

Tobias Burnus <burnus at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |burnus at gcc dot gnu.org

--- Comment #2 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-02-01 16:46:42 UTC ---
Works for me on x86-64-linux. There is some possibility that the patch for PR
45700 fixed that issue (committed: 2010-11-26) - at least that is the only
thing which vaguely goes into the direction of the ICE (internal compiler
error).

Thus, one possibility would be to try a newer version.

Other than that:

gfortran -v -save-temps -Wunused -Wuninitialized -fsecond-underscore
-fconvert=big-endian -ffixed-line-length-132 -O3 -funroll-loops -c

You use a large number of options. Can you cut down the number of options and
see whether, e.g., -O2 or -O1 or -O0 is enough to trigger the issue?

[Bug fortran/47574] internal compiler error: in build2_stat, at tree.c:3795

[mlosch@uni-bremen.de]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47574

--- Comment #3 from Martin Losch <mlosch@uni-bremen.de> 2011-02-01 17:30:56 UTC ---
gfortran -O3 -c exch2_uv_agrid_3d_rl.f
gives the same error

gfortran -O2 -c exch2_uv_agrid_3d_rl.f
works for this file (for others that are similar I need -O1).

I have to admit that I have never ventured into building gfortran/gcc myself,
but downloaded the binaries for Mac OS X 10.6 here:
<http://hpc.sourceforge.net/>. I just posted this bug, because I thought it
would be useful. If my rebuilding gfortran from source is required I won't be
of much help.

(In reply to comment #2)
> Works for me on x86-64-linux. There is some possibility that the patch for PR
> 45700 fixed that issue (committed: 2010-11-26) - at least that is the only
> thing which vaguely goes into the direction of the ICE (internal compiler
> error).
> 
> Thus, one possibility would be to try a newer version.
> 
> Other than that:
> 
> gfortran -v -save-temps -Wunused -Wuninitialized -fsecond-underscore
> -fconvert=big-endian -ffixed-line-length-132 -O3 -funroll-loops -c
> 
> You use a large number of options. Can you cut down the number of options and
> see whether, e.g., -O2 or -O1 or -O0 is enough to trigger the issue?

[Bug fortran/47574] internal compiler error: in build2_stat, at tree.c:3795

[dominiq at lps dot ens.fr]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47574

--- Comment #4 from Dominique d'Humieres <dominiq at lps dot ens.fr> 2011-02-01 18:32:44 UTC ---
I cannot reproduce it on x86_64-apple-darwin10 with all the options/versions I
have tried (including gcc version 4.6.0 20101106 (experimental) [trunk revision
166401]).

One possibility could be a miscompilation due to gmp/mpfr/mpc: I use

GMP version 5.0.1, MPFR version 3.0.0, MPC version 0.8.2

Do you know a minimal use of gdb?

[Bug fortran/47574] internal compiler error: in build2_stat, at tree.c:3795

[dominiq at lps dot ens.fr]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47574

--- Comment #5 from Dominique d'Humieres <dominiq at lps dot ens.fr> 2011-02-01 18:59:25 UTC ---
I have had a look at the test code. Could you try 

(1) to comment the call to EXCH2_UV_AGRID_3D_RL,
(2) the same for the (two?) COMMONs,

and see if one of these changes makes the ICE disappear?

[Bug fortran/47574] internal compiler error: in build2_stat, at tree.c:3795

[mlosch@uni-bremen.de]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47574

--- Comment #6 from Martin Losch <mlosch@uni-bremen.de> 2011-02-02 09:00:10 UTC ---
(In reply to comment #4)
As far as I can see (from the header files that came with pre-compiled
binaries) this was used:
#define MPFR_VERSION_STRING "2.4.1"

#define MPC_VERSION_STRING "0.8.1"

#define __GNU_MP_VERSION 4
#define __GNU_MP_VERSION_MINOR 3
#define __GNU_MP_VERSION_PATCHLEVEL 1

I have used gdb for minimally, but what is its use here? I cannot create an
executable if I do not reduce the optimization level. What do you suggest?

[Bug fortran/47574] internal compiler error: in build2_stat, at tree.c:3795

[mlosch@uni-bremen.de]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47574

--- Comment #7 from Martin Losch <mlosch@uni-bremen.de> 2011-02-02 09:09:07 UTC ---
(In reply to comment #5)
> I have had a look at the test code. Could you try 
> 
> (1) to comment the call to EXCH2_UV_AGRID_3D_RL,
> (2) the same for the (two?) COMMONs,
> 
> and see if one of these changes makes the ICE disappear?

I do not understand (1): commenting out the call to this routine elsewhere does
not modify the compilation of the routine. If you meant commenting out the
calls to EXCH2_RL1_CUBE, then this does not make the ICE go away.
(2) I commented out all (five) COMMON blocks (but not the associated
declarations of variables), and the ICE does not go away, either. 

What makes the problem go away is commenting out line 949.

[Bug fortran/47574] internal compiler error: in build2_stat, at tree.c:3795

[dominiq at lps dot ens.fr]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47574

--- Comment #8 from Dominique d'Humieres <dominiq at lps dot ens.fr> 2011-02-02 09:35:31 UTC ---
(In reply to comment #6)
> I have used gdb for minimally, but what is its use here? I cannot create an
> executable if I do not reduce the optimization level. What do you suggest?

I suggest to run gdb on f951 to see the path leading to the error

exch2_uv_agrid_3d_rl.f:293:0: internal compiler error: in build2_stat, at
tree.c:3795

gfortran is located in /some_path/bin. You'll find f951 in
/some_path/libexec/gcc/platform/version/

(gdb /opt/gcc/gcc4.6w/libexec/gcc/x86_64-apple-darwin10.6.0/4.6.0/f951 for me).

Set a breakpoint to fancy_abort, run the code and do a backtrace.

(In reply to comment #7)
> What makes the problem go away is commenting out line 949.

There is no line 949 in attachment 23201. The goal is to reduce the file to the
"minimal" size reproducing the ICE. CALL and COMMON have triggered bugs in the
past, hence my question (note that in the attachment 23201 there are only two
COMMONs: /EEPARAMS_L/ and /EEPARAMS_I/).

[Bug fortran/47574] internal compiler error: in build2_stat, at tree.c:3795

[mlosch@uni-bremen.de]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47574

Martin Losch <mlosch@uni-bremen.de> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
  Attachment #23201|0                           |1
        is obsolete|                            |

--- Comment #9 from Martin Losch <mlosch@uni-bremen.de> 2011-02-02 10:08:39 UTC ---
Created attachment 23212
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=23212
simplified fortran code to reproduce problem

commenting either lines 91 and 92 or 98 and 99 gets rid off the ICE

[Bug fortran/47574] internal compiler error: in build2_stat, at tree.c:3795

[mlosch@uni-bremen.de]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47574

--- Comment #10 from Martin Losch <mlosch@uni-bremen.de> 2011-02-02 10:28:15 UTC ---
(In reply to comment #8)
> (In reply to comment #6)
> > I have used gdb for minimally, but what is its use here? I cannot create an
> > executable if I do not reduce the optimization level. What do you suggest?
> 
> I suggest to run gdb on f951 to see the path leading to the error
> 
> exch2_uv_agrid_3d_rl.f:293:0: internal compiler error: in build2_stat, at
> tree.c:3795
> 
> gfortran is located in /some_path/bin. You'll find f951 in
> /some_path/libexec/gcc/platform/version/
> 
> (gdb /opt/gcc/gcc4.6w/libexec/gcc/x86_64-apple-darwin10.6.0/4.6.0/f951 for me).
> 
> Set a breakpoint to fancy_abort, run the code and do a backtrace.

I am afraid that's beyond my capabilities. my gdb does not off a breakpoint
fancy_abort and since I only download precompiled binaries the gbd does not
even find the object files. Here's the beginning of the output:

>gdb /usr/local/libexec/gcc/x86_64-apple-darwin10.4.0/4.6.0/f951
GNU gdb 6.3.50-20050815 (Apple version gdb-1510) (Wed Sep 22 02:45:02 UTC 2010)
Copyright 2004 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "x86_64-apple-darwin"...Reading symbols for shared
libraries ...
warning: Could not find object file
"/Users/gkhanna/build/x86_64-apple-darwin10.4.0/libgcc/_muldi3_s.o" - no debug
information available for "../../../gcc-4.6-20101106/libgcc/../gcc/libgcc2.c".

[...]
> 
> (In reply to comment #7)
> > What makes the problem go away is commenting out line 949.
> 
> There is no line 949 in attachment 23201 [details]. The goal is to reduce the file to the
> "minimal" size reproducing the ICE. CALL and COMMON have triggered bugs in the
> past, hence my question (note that in the attachment 23201 [details] there are only two
> COMMONs: /EEPARAMS_L/ and /EEPARAMS_I/).

This is embarrissing. I apologize for attaching another wrong file (the correct
file name would have been exch2_uv_agrid_3d_rl.f). I have now removed
everything from this file that seems unnecessary to reproduce the ICE and have
attached it as strippeddownfile.f (attachment 23212).

[Bug fortran/47574] internal compiler error: in build2_stat, at tree.c:3795

[dominiq at lps dot ens.fr]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47574

--- Comment #11 from Dominique d'Humieres <dominiq at lps dot ens.fr> 2011-02-02 11:22:39 UTC ---
> This is embarrissing. I apologize for attaching another wrong file (the correct
> file name would have been exch2_uv_agrid_3d_rl.f). I have now removed
> everything from this file that seems unnecessary to reproduce the ICE and have
> attached it as strippeddownfile.f (attachment 23212 [details]).

Now I can reproduce it with revisions 166102, 166367, 166401, 166533, and
167096, but not with revision 162456 nor revision 167584.

So the bug seems to have been introduced between revisions 162456 and 166102
and fixed between revisions 167096 and 167584. You are unlucky to be right
where the bug is;-(I'll look later to see if I can refine the windows and try
to spot the right pr). Meanwhile you should notify Gaurav Khanna about the bug
and ask him if he his planning a more recent build.

[Bug fortran/47574] internal compiler error: in build2_stat, at tree.c:3795

[dominiq at lps dot ens.fr]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47574

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rguenther at suse dot de

--- Comment #12 from Dominique d'Humieres <dominiq at lps dot ens.fr> 2011-02-02 16:25:42 UTC ---
This pr looks like a duplicate of pr46664 fixed at revision 167173 (the test in
attachment 23212 gives an ICE also at revision 167138).

[Bug fortran/47574] internal compiler error: in build2_stat, at tree.c:3795

[dominiq at lps dot ens.fr]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47574

--- Comment #13 from Dominique d'Humieres <dominiq at lps dot ens.fr> 2011-02-03 20:16:40 UTC ---
Further reduced test case

! { dg-do compile }
      SUBROUTINE EXCH2_UV_AGRID_3D_RL( uPhi, vPhi, myNz )

      IMPLICIT NONE

      INTEGER, parameter :: sNx=32, sNy=32, OLx=4, OLy=4

      INTEGER myNz
      Real*8 uPhi(1-OLx:sNx+OLx,1-OLy:sNy+OLy,myNz,3,1)
      Real*8 vPhi(1-OLx:sNx+OLx,1-OLy:sNy+OLy,myNz,3,1)

      INTEGER i,j,k,bi,bj
      Real*8 uLoc(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
      Real*8 vLoc(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
      Real*8 negOne

      negOne = 1.
        DO k = 1,myNz
         DO j = 1-OLy,sNy+OLy
          DO i = 1-OLx,sNx+OLx
           uLoc(i,j) = uPhi(i,j,k,bi,bj)
           vLoc(i,j) = vPhi(i,j,k,bi,bj)
          ENDDO
         ENDDO
         DO j = 1-OLy,sNy+OLy
          DO i = 1,OLx
           uPhi(1-i,j,k,bi,bj) = vLoc(1-i,j)
           vPhi(1-i,j,k,bi,bj) = uLoc(1-i,j)*negOne
          ENDDO
         ENDDO

        ENDDO

      END

It gives an ICE at revision 167172, but not at revision 167173, hence a
duplicate of pr46664. Note that revision 167173 did not add a test case. Should
not the above test be added to the test suite before I close this PR as a
duplicate?

[Bug fortran/47574] internal compiler error: in build2_stat, at tree.c:3795

[tkoenig at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47574

--- Comment #14 from Thomas Koenig <tkoenig at gcc dot gnu.org> 2011-02-05 10:35:28 UTC ---
Author: tkoenig
Date: Sat Feb  5 10:35:24 2011
New Revision: 169850

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=169850
Log:
2001-02-05  Thomas Koenig  <tkoenig@gcc.gnu.org>

    PR fortran/47574
    * gfortran.dg/pr47574.f90:  New test.


Added:
    trunk/gcc/testsuite/gfortran.dg/pr47574.f90
Modified:
    trunk/gcc/testsuite/ChangeLog

[Bug fortran/47574] internal compiler error: in build2_stat, at tree.c:3795

[tkoenig at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47574

Thomas Koenig <tkoenig at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
                 CC|                            |tkoenig at gcc dot gnu.org
         Resolution|                            |FIXED

--- Comment #15 from Thomas Koenig <tkoenig at gcc dot gnu.org> 2011-02-05 10:39:07 UTC ---
Test case committed to trunk, closing.