[Bug middle-end/47566] New: ICE in vn_reference_lookup

[Bug middle-end/47566] New: ICE in vn_reference_lookup

[Joost.VandeVondele at pci dot uzh.ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47566

           Summary: ICE in vn_reference_lookup
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: Joost.VandeVondele@pci.uzh.ch


current trunk fails with ICE compiling with LTO cp2k.

/data03/vondele/gnu/gcc_trunk/install/libexec/gcc/x86_64-unknown-linux-gnu/4.6.0/lto1
-march=amdfam10 -mcx16 -msahf -mpopcnt -mabm --param l1-cache-size=64 --param
l1-cache-line-size=64 --param l2-cache-size=512 -mtune=amdfam10 -quiet -dumpdir
/data03/vondele/cp2k_gcc/cp2k/makefiles/../exe/gfortran-test24/ -dumpbase
cp2k.sopt.ltrans1 -auxbase-strip cp2k.sopt.ltrans1.ltrans.o -O3 -version
-ffree-form -funroll-loops -ffast-math -fuse-linker-plugin -fltrans
cp2k.sopt.ltrans1.o -o cp2k.sopt.ltrans1.s -v

GNU GIMPLE (GCC) version 4.6.0 20110201 (experimental) [trunk revision 169466]
(x86_64-unknown-linux-gnu)
        compiled by GNU C version 4.6.0 20110201 (experimental) [trunk revision
169466], GMP version 4.3.2, MPFR version 2.4.2, MPC version 0.8.2
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
GNU GIMPLE (GCC) version 4.6.0 20110201 (experimental) [trunk revision 169466]
(x86_64-unknown-linux-gnu)
        compiled by GNU C version 4.6.0 20110201 (experimental) [trunk revision
169466], GMP version 4.3.2, MPFR version 2.4.2, MPC version 0.8.2
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
In file included from :520:0:
/data03/vondele/cp2k_gcc/cp2k/makefiles/../src/fft_tools.F: In function
‘fft3d_pb’:
/data03/vondele/cp2k_gcc/cp2k/makefiles/../src/fft_tools.F:994:0: internal
compiler error: Segmentation fault

in gdb I get

Program received signal SIGSEGV, Segmentation fault.
0x000000000079583b in vn_reference_lookup (op=0x7fffef4a4460,
vuse=0x7ffff532eb40, kind=VN_WALK, vnresult=0x0) at
../../gcc/gcc/tree-ssa-sccvn.c:1543
1543      vr1.vuse = vuse ? SSA_VAL (vuse) : NULL_TREE;
(gdb) bt
#0  0x000000000079583b in vn_reference_lookup (op=0x7fffef4a4460,
vuse=0x7ffff532eb40, kind=VN_WALK, vnresult=0x0) at
../../gcc/gcc/tree-ssa-sccvn.c:1543
#1  0x0000000000787a0c in eliminate () at ../../gcc/gcc/tree-ssa-pre.c:4331
#2  0x000000000078a2a5 in execute_pre (do_fre=0 '\000') at
../../gcc/gcc/tree-ssa-pre.c:4901
#3  execute_pre (do_fre=0 '\000') at ../../gcc/gcc/tree-ssa-pre.c:4845
#4  0x000000000064fdb9 in execute_one_pass (pass=0x10968c0) at
../../gcc/gcc/passes.c:1561
#5  0x0000000000650065 in execute_pass_list (pass=0x10968c0) at
../../gcc/gcc/passes.c:1616
#6  0x0000000000650077 in execute_pass_list (pass=0x10957e0) at
../../gcc/gcc/passes.c:1617
#7  0x000000000071b481 in tree_rest_of_compilation (fndecl=0x7ffff5c2ff00) at
../../gcc/gcc/tree-optimize.c:422
#8  0x000000000085884f in cgraph_expand_function (node=0x7ffff54599a0) at
../../gcc/gcc/cgraphunit.c:1563
#9  0x000000000085a46a in cgraph_expand_all_functions () at
../../gcc/gcc/cgraphunit.c:1622
#10 cgraph_optimize () at ../../gcc/gcc/cgraphunit.c:1882
#11 0x00000000004b9fdf in lto_main () at ../../gcc/gcc/lto/lto.c:2457

details of gfortran -v:

gfortran -v
Using built-in specs.
COLLECT_GCC=gfortran
COLLECT_LTO_WRAPPER=/data03/vondele/gnu/gcc_trunk/install/libexec/gcc/x86_64-unknown-linux-gnu/4.6.0/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: ../gcc/configure
--prefix=/data03/vondele/gnu/gcc_trunk/install --enable-languages=c,c++,fortran
--disable-multilib --enable-plugins --enable-cloog-backend=isl
--with-ppl=/data03/vondele/gnu/ppl-0.11/install
--with-cloog=/data03/vondele/gnu/cloog-0.16.1/install/
--with-libelf=/data03/vondele/gnu/libelf-0.8.13/install --enable-gold
--enable-checking=release
Thread model: posix
gcc version 4.6.0 20110201 (experimental) [trunk revision 169466] (GCC)

[Bug middle-end/47566] ICE in vn_reference_lookup

[Joost.VandeVondele at pci dot uzh.ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47566

--- Comment #1 from Joost VandeVondele <Joost.VandeVondele at pci dot uzh.ch> 2011-02-01 09:42:12 UTC ---
gzipped testcase (2.7Mb) downloadable from

http://www.pci.uzh.ch/vandevondele/tmp/cp2k.sopt.ltrans1.o.gz

[Bug middle-end/47566] ICE in vn_reference_lookup

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47566

--- Comment #2 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-02-01 11:53:09 UTC ---
I think we need source code (LTO bytecode isn't really portable).

It looks like that vuse is somehow bogus - mind posting the output of

(gdb) call debug_tree (vuse)

at that point?

[Bug middle-end/47566] ICE in vn_reference_lookup

[Joost.VandeVondele at pci dot uzh.ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47566

--- Comment #3 from Joost VandeVondele <Joost.VandeVondele at pci dot uzh.ch> 2011-02-01 12:04:46 UTC ---
(In reply to comment #2)
> I think we need source code (LTO bytecode isn't really portable).

oops... that's building CP2K. Let me see if I can reproduce this with this
night's tarball.

> 
> (gdb) call debug_tree (vuse)
> 
> at that point?

(gdb)  call debug_tree (vuse)
 <var_decl 0x7ffff532eb40 .MEM
    type <void_type 0x7ffff7e84d20 void VOID
        align 8 symtab 0 alias set -1 structural equality
        pointer_to_this <pointer_type 0x7ffff7e84dc8>>
    used static external VOID file <built-in> line 0 col 0
    align 8>

[Bug middle-end/47566] ICE in vn_reference_lookup

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47566

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

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

--- Comment #4 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-02-01 12:12:13 UTC ---
(In reply to comment #3)
> (In reply to comment #2)
> > I think we need source code (LTO bytecode isn't really portable).
> 
> oops... that's building CP2K. Let me see if I can reproduce this with this
> night's tarball.
> 
> > 
> > (gdb) call debug_tree (vuse)
> > 
> > at that point?
> 
> (gdb)  call debug_tree (vuse)
>  <var_decl 0x7ffff532eb40 .MEM
>     type <void_type 0x7ffff7e84d20 void VOID
>         align 8 symtab 0 alias set -1 structural equality
>         pointer_to_this <pointer_type 0x7ffff7e84dc8>>
>     used static external VOID file <built-in> line 0 col 0
>     align 8>

That's indeed invalid - it should be an SSA name.  This means some
earlier pass messed up (or PRE itself).  The bug shouldn't depend
on LTO (apart from maybe requiring some cross-module inlining to trigger).

[Bug middle-end/47566] ICE in vn_reference_lookup

[Joost.VandeVondele at pci dot uzh.ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47566

--- Comment #5 from Joost VandeVondele <Joost.VandeVondele at pci dot uzh.ch> 2011-02-01 12:23:35 UTC ---
(In reply to comment #4)
> That's indeed invalid - it should be an SSA name.  This means some
> earlier pass messed up (or PRE itself).  The bug shouldn't depend
> on LTO (apart from maybe requiring some cross-module inlining to trigger).

The same problem doesn't happen without LTO (but otherwise compiled with the
same options). I guess it needs the cross-module inlining.

I'll be uploading a tgz with sources.

[Bug middle-end/47566] ICE in vn_reference_lookup

[Joost.VandeVondele at pci dot uzh.ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47566

--- Comment #6 from Joost VandeVondele <Joost.VandeVondele at pci dot uzh.ch> 2011-02-01 12:29:36 UTC ---
to reproduce from sources

wget http://www.pci.uzh.ch/vandevondele/tmp/cp2k.tgz
tar -xzvf cp2k.tgz
cd cp2k/makefiles
make -j ARCH=gfortran-test24 VERSION=sopt

this assumes that you have lapack and blas installed etc. The file

cp2k/arch/gfortran-test24.sopt

can be changed to modify compile options (or directories for lapack/blas). With

make -j ARCH=gfortran-test24 VERSION=sopt distclean

a new build can be started from scratch

[Bug middle-end/47566] ICE in vn_reference_lookup

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47566

--- Comment #7 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-02-01 14:46:56 UTC ---
Hm, you are using -O0 for the compile and -O3 ... for the link step?  Should
work in theory, but of course isn't tested thoroughly.

[Bug middle-end/47566] ICE in vn_reference_lookup

[Joost.VandeVondele at pci dot uzh.ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47566

--- Comment #8 from Joost VandeVondele <Joost.VandeVondele at pci dot uzh.ch> 2011-02-01 14:53:44 UTC ---
(In reply to comment #7)
> Hm, you are using -O0 for the compile and -O3 ... for the link step?  Should
> work in theory, but of course isn't tested thoroughly.

Right :-) I'm trying to test this thoroughly... 

seems like a useful trick to speedup parallel builds of Fortran programs (quick
-O0 build to satisfy module dependencies, massively parallel and thus hopefully
fast lto without the dependencies).

[Bug middle-end/47566] ICE in vn_reference_lookup

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47566

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2011.02.01 15:36:11
         AssignedTo|unassigned at gcc dot       |rguenth at gcc dot gnu.org
                   |gnu.org                     |
     Ever Confirmed|0                           |1

--- Comment #9 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-02-01 15:36:11 UTC ---
I can reproduce it.  I also run into

In file included from :425:0:
/tmp/cp2k/makefiles/../src/realspace_grid_types.F: In function
'rs_pw_transfer_replicated':
/tmp/cp2k/makefiles/../src/realspace_grid_types.F:816:0: error: non-trivial
conversion at assignment
struct array3_real(kind=8)
struct array3_real(kind=8)
# .MEM_755 = VDEF <.MEM_649>
grid = D.39399_277->r;

and a couple of similar ICEs in other ltrans units.  Probably the known
restrict vs. non-restrict bug.

The bug happens when optimizing fft3d_pb, it also happens with -fno-inline
so indeed the bug might be triggered by the mix of -O0 and -O3 (thus, by
not running early optimizations).

Seems to be -ffast-math vs. non-fast-math.  We fold calls during
PRE insertion which turns cabs into components (complex lowering).

That folding,

        folded = build_call_array (currop->type,
                                   (TREE_CODE (fn) == FUNCTION_DECL
                                    ? build_fold_addr_expr (fn) : fn),
                                   nargs, args);

can create arbitrary number of expressions, including for some reason
non-gimple reg vars.  In particular fold_builtin_cabs returns

__builtin_sqrt (__builtin_pow (SAVE_EXPR <REALPART_EXPR <SAVE_EXPR
<val.767_1280>>>, 2.0e+0) + __builtin_pow (SAVE_EXPR <IMAGPART_EXPR <SAVE_EXPR
<val.767_1280>>>, 2.0e+0))

and then save-expr gimplification introduces the non-register temporary
as a result of SSA_NAME save-expr (which is unnecessary anyway).

The following fixes the ICE for me:

Index: builtins.c
===================================================================
--- builtins.c  (revision 169476)
+++ builtins.c  (working copy)
@@ -652,9 +652,10 @@ target_char_cast (tree cst, char *p)
 static tree
 builtin_save_expr (tree exp)
 {
-  if (TREE_ADDRESSABLE (exp) == 0
-      && (TREE_CODE (exp) == PARM_DECL
-         || (TREE_CODE (exp) == VAR_DECL && !TREE_STATIC (exp))))
+  if (TREE_CODE (exp) == SSA_NAME
+      || (TREE_ADDRESSABLE (exp) == 0
+         && (TREE_CODE (exp) == PARM_DECL
+             || (TREE_CODE (exp) == VAR_DECL && !TREE_STATIC (exp)))))
     return exp;

   return save_expr (exp);

[Bug middle-end/47566] ICE in vn_reference_lookup

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47566

--- Comment #10 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-02-01 15:40:30 UTC ---
Testcase:

/* { dg-lto-do run } */
/* { dg-extra-ld-options "-O2 -ffast-math" } */

double cabs(_Complex double);
double __attribute__((used))
foo (_Complex double x, int b)
{
  if (b)
    x = 0;
  return cabs(x);
}
int main() { return 0; }

[Bug middle-end/47566] ICE in vn_reference_lookup

[Joost.VandeVondele at pci dot uzh.ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47566

--- Comment #11 from Joost VandeVondele <Joost.VandeVondele at pci dot uzh.ch> 2011-02-01 15:52:42 UTC ---
(In reply to comment #9)
> In file included from :425:0:
> /tmp/cp2k/makefiles/../src/realspace_grid_types.F: In function
> 'rs_pw_transfer_replicated':
> /tmp/cp2k/makefiles/../src/realspace_grid_types.F:816:0: error: non-trivial
> conversion at assignment

yes, that is PR45586. Can be worked around with either release checking (which
I have enable right now) or changing src/realspace_grid_types.F
to use
     REAL(KIND=dp), DIMENSION ( :, :, : ), POINTER :: r   ! the grid
instead of
     REAL(KIND=dp), DIMENSION ( :, :, : ), ALLOCATABLE :: r   ! the grid



> The following fixes the ICE for me:

cool.

[Bug middle-end/47566] ICE in vn_reference_lookup

[Joost.VandeVondele at pci dot uzh.ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47566

--- Comment #12 from Joost VandeVondele <Joost.VandeVondele at pci dot uzh.ch> 2011-02-01 21:00:18 UTC ---
The patch from comment #9 allows a release checking compiler to build CP2K with
LTO.

[Bug middle-end/47566] ICE in vn_reference_lookup

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47566

--- Comment #13 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-02-02 09:59:29 UTC ---
Author: rguenth
Date: Wed Feb  2 09:59:23 2011
New Revision: 169518

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=169518
Log:
2011-02-02  Richard Guenther  <rguenther@suse.de>

    PR tree-optimization/47566
    * builtins.c (builtin_save_expr): No SAVE_EXPR for SSA_NAMEs.

    * gcc.dg/lto/20110201-1_0.c: New testcase.

Added:
    trunk/gcc/testsuite/gcc.dg/lto/20110201-1_0.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/builtins.c
    trunk/gcc/testsuite/ChangeLog

[Bug middle-end/47566] ICE in vn_reference_lookup

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47566

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |4.6.0

--- Comment #14 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-02-02 10:00:49 UTC ---
Fixed.