[Bug lto/58723] New: ICE in lto_output_edge, at lto-cgraph.c:300 for OpenMP's simd reduction

[Bug lto/58723] New: ICE in lto_output_edge, at lto-cgraph.c:300 for OpenMP's simd reduction

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58723

            Bug ID: 58723
           Summary: ICE in lto_output_edge, at lto-cgraph.c:300 for
                    OpenMP's simd reduction
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: lto
          Assignee: unassigned at gcc dot gnu.org
          Reporter: burnus at gcc dot gnu.org
                CC: jakub at gcc dot gnu.org, rguenth at gcc dot gnu.org

Created attachment 31000
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=31000&action=edit
Delta reduced C++ test case

That's with gcc version 4.9.0 20131014 (experimental) [trunk revision 203511]
(GCC) on an x86-64-gnu-linux system.


$ g++ -std=c++11 -O1 -flto -fopenmp testcase20.ii

testcase20.ii:40:1: internal compiler error: in lto_output_edge, at
lto-cgraph.c:300
 }  // namespace std
 ^
Please submit a full bug report,



It works when compiled without -fopenmp. The only OpenMP code is:

#pragma omp simd reduction(+:area)
    for (int yi = 0; yi < count; ++yi)
      ...

(where delta has removed the "area" assignment.)

[Bug lto/58723] ICE in lto_output_edge, at lto-cgraph.c:300 for OpenMP's simd reduction

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58723

--- Comment #1 from Tobias Burnus <burnus at gcc dot gnu.org> ---
The failure is for the assert:

295           /* Flags that should not appear on indirect calls.  */
296           gcc_assert (!(flags & (ECF_LOOPING_CONST_OR_PURE
297                                  | ECF_MAY_BE_ALLOCA
298                                  | ECF_SIBCALL
299                                  | ECF_LEAF
300                                  | ECF_NOVOPS)));

Here, (flags & ECF_LEAF) != 0. The edge->caller is:

(gdb) p dump_cgraph_node(stdout, edge->caller)

_ZStL17DoFinalizeBooleanSt8XPBoolOpiPKSt5XPBoxPSt6vectorIS0_SaIS0_EE/0
(std::DoFinalizeBoolean(std::XPBoolOp, int, std::XPBox const*,
std::vector<std::XPBox, std::allocator<std::XPBox> >*)) @0x2aaaac1f1e40
Type: function definition analyzed
Visibility: prevailing_def_ironly
References:
Referring:
Availability: local
Function flags: body local
Called by: _ZNSt7XPClass4finiEPSt6vectorISt5XPBoxSaIS1_EE/1 (1.00 per call)
Calls:
Has 3 outgoing edges for indirect calls.


My suspicion is that this is due to:

DEF_INTERNAL_FN (GOMP_SIMD_VF, ECF_CONST | ECF_LEAF | ECF_NOTHROW)

[Bug lto/58723] [4.9 Regression] ICE in lto_output_edge, at lto-cgraph.c:300 for OpenMP's simd reduction

[reichelt at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58723

Volker Reichelt <reichelt at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2013-11-10
                 CC|                            |reichelt at gcc dot gnu.org
      Known to work|                            |4.5.0, 4.6.0, 4.7.0, 4.8.0
            Summary|ICE in lto_output_edge, at  |[4.9 Regression] ICE in
                   |lto-cgraph.c:300 for        |lto_output_edge, at
                   |OpenMP's simd reduction     |lto-cgraph.c:300 for
                   |                            |OpenMP's simd reduction
     Ever confirmed|0                           |1
      Known to fail|                            |4.9.0

--- Comment #2 from Volker Reichelt <reichelt at gcc dot gnu.org> ---
Confirmed.

Even shorter testcase (compile with "-O -flto -fopenmp"):

=======================================
void foo(int n)
{
  int i;
  #pragma omp simd reduction(+:n)
  for (i = 0; i < 99; ++i) ;
}
=======================================

The regression appeared between 4.9-20131005 and 4.9.0-20131012.

[Bug lto/58723] [4.9 Regression] ICE in lto_output_edge, at lto-cgraph.c:300 for OpenMP's simd reduction

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58723

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.9.0

[Bug middle-end/58723] [4.9 Regression] ICE in lto_output_edge, at lto-cgraph.c:300 for OpenMP's simd reduction

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58723

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P1
          Component|lto                         |middle-end

[Bug lto/58723] [4.9 Regression] ICE in lto_output_edge, at lto-cgraph.c:300 for OpenMP's simd reduction

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58723

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

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

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
Looks like cgraph doesn't know about internal functions and treats them as
indirect calls ... I suppose we shouldn't record any call edges for internal
fns which all should expand to non-calls (and should all be 'leaf')?
Runs into interesting fallout though ...

The other variant is to forcefully build non-indirect edges, also with
interesting fallout.

Bah.

Honza?

Internal functions are like builtins just we don't have a decl (and thus
a cgraph node) for them.  They are just special instructions, not really
calls to "functions".

[Bug middle-end/58723] [4.9 Regression] ICE in lto_output_edge, at lto-cgraph.c:300 for OpenMP's simd reduction

[mpolacek at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58723

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

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

--- Comment #4 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Yeah, I hit exactly this as well, with DEF_INTERNAL_FN (UBSAN_NULL, ECF_LEAF |
ECF_NOTHROW).  The UBSAN_NULL is just like a macro, it expands to a GIMPLE_COND
later on.  It has to be leaf - otherwise it wouldn't be possible to have it in
the middle of a BB.  Temporarily, I disabled the tests with -flto.

[Bug middle-end/58723] [4.9 Regression] ICE in lto_output_edge, at lto-cgraph.c:300 for OpenMP's simd reduction

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58723

--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
Created attachment 31299
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=31299&action=edit
patch

Patch fixing the testcase (but otherwise untested - we don't have too many
internal fn testcases).

[Bug middle-end/58723] [4.9 Regression] ICE in lto_output_edge, at lto-cgraph.c:300 for OpenMP's simd reduction

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58723

--- Comment #6 from Tobias Burnus <burnus at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #5)
> Created attachment 31299 [details]
> Patch fixing the testcase (but otherwise untested - we don't have too many
> internal fn testcases).

Doesn't work for me. With the test case of comment 0 (attachment 31000) I get
with
  g++ -std=c++11 -fopenmp -flto -O1 test.ii
the - new - ICE

cc1plus: internal compiler error: in expand_call_inline, at tree-inline.c:4076
0xc046a9 expand_call_inline
        ../../gcc/tree-inline.c:4076
0xc046a9 gimple_expand_calls_inline
        ../../gcc/tree-inline.c:4430
0xc046a9 optimize_inline_calls(tree_node*)
        ../../gcc/tree-inline.c:4569
0x109bbdb inline_transform(cgraph_node*)
        ../../gcc/ipa-inline-transform.c:435

[Bug middle-end/58723] [4.9 Regression] ICE in lto_output_edge, at lto-cgraph.c:300 for OpenMP's simd reduction

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58723

--- Comment #7 from Tobias Burnus <burnus at gcc dot gnu.org> ---
(In reply to Tobias Burnus from comment #6)
> (In reply to Richard Biener from comment #5)
> > Created attachment 31299 [details]
> > Patch fixing the testcase (but otherwise untested - we don't have too many
> > internal fn testcases).
> Doesn't work for me.

If one dumps the bb, one finds a call to GOMP_SIMD_VF.

Using the following patch on top of yours fixes the issue for the reduced test
case and for the compilation to the *.o files in the real-world code:

--- a/gcc/tree-inline.c
+++ b/gcc/tree-inline.c
@@ -4066,5 +4070,5 @@ expand_call_inline (basic_block bb, gimple stmt,
copy_body_data *id)

   /* From here on, we're only interested in CALL_EXPRs.  */
-  if (gimple_code (stmt) != GIMPLE_CALL)
+  if (gimple_code (stmt) != GIMPLE_CALL || gimple_call_internal_p (stmt))
     goto egress;

 * * *

Unfortunately, the lto1 phase still fails for the big code. For that one, I
get:

xpboolean.cc:3744:8: internal compiler error: in expand_GOMP_SIMD_VF, at
internal-fn.c:137
0x7b48b7 expand_GOMP_SIMD_VF
        ../../gcc/internal-fn.c:137
0x5fe497 expand_call_stmt
        ../../gcc/cfgexpand.c:2164
0x5fe497 expand_gimple_stmt_1
        ../../gcc/cfgexpand.c:3143
0x5fe497 expand_gimple_stmt
        ../../gcc/cfgexpand.c:3295

[Bug middle-end/58723] [4.9 Regression] ICE in lto_output_edge, at lto-cgraph.c:300 for OpenMP's simd reduction

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58723

--- Comment #8 from Tobias Burnus <burnus at gcc dot gnu.org> ---
Created attachment 31302
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=31302&action=edit
Small test case: test.tar.gz

I managed to create a test case.

The attached test case is essentially attachment 31000, except of changing it
to a .cc file and adding #include<vector> - and writing a simple main()
function for it.

$  g++ -std=c++11 -flto -fopenmp-simd -Ofast test.cc test-main.cc
test.cc: In member function 'fini':
test.cc:31:6: internal compiler error: in expand_GOMP_SIMD_LANE, at
internal-fn.c:129
 void XPClass::fini(std::vector<XPBox> *__restrict out) noexcept {
      ^
0x7b48d7 expand_GOMP_SIMD_LANE
        ../../gcc/internal-fn.c:129

[Bug middle-end/58723] [4.9 Regression] ICE in lto_output_edge, at lto-cgraph.c:300 for OpenMP's simd reduction

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58723

--- Comment #9 from Richard Biener <rguenth at gcc dot gnu.org> ---
We fail to stream cfun->has_force_vect_loops.

[Bug middle-end/58723] [4.9 Regression] ICE in lto_output_edge, at lto-cgraph.c:300 for OpenMP's simd reduction

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58723

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
  Attachment #31299|0                           |1
        is obsolete|                            |

--- Comment #10 from Richard Biener <rguenth at gcc dot gnu.org> ---
Created attachment 31305
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=31305&action=edit
updated patch

lto1 also does not get -fopenmp[-simd] passed, not sure if that is needed
though.

The simple testcase from comment #2 already fails with

> ./xgcc -B. -B ../x86_64-unknown-linux-gnu/libgomp/ -B ../x86_64-unknown-linux-gnu/libgomp/.libs -O -flto -fopenmp t.i -r -nostdlib
t.i: In function 'foo':
t.i:1:6: internal compiler error: in expand_GOMP_SIMD_VF, at internal-fn.c:137
 void foo(int n)
      ^
0x8c4d19 expand_GOMP_SIMD_VF


updated patch attached that fixes the streaming and thus runs the vectorizer
at -O1 during LTRANs (but it does nothing).

[Bug middle-end/58723] [4.9 Regression] ICE in lto_output_edge, at lto-cgraph.c:300 for OpenMP's simd reduction

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58723

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
  Attachment #31305|0                           |1
        is obsolete|                            |

--- Comment #11 from Richard Biener <rguenth at gcc dot gnu.org> ---
Created attachment 31306
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=31306&action=edit
updated patch

And there is also has_simduid_loops and loop->safelen and loop->force_vect.
Also loop->simduid but 1) I don't know how to stream it, 2) it seems to work
without.  But I see the vectorizer looks at DECL_UID (loop->simduid)), so
"work without" may mean it just doesn't vectorize the thing but cleans up.

[Bug middle-end/58723] [4.9 Regression] ICE in lto_output_edge, at lto-cgraph.c:300 for OpenMP's simd reduction

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58723

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
  Attachment #31306|0                           |1
        is obsolete|                            |

--- Comment #12 from Richard Biener <rguenth at gcc dot gnu.org> ---
Created attachment 31307
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=31307&action=edit
updated patch

Indeed.

t.i:1:6: note: === vect_analyze_data_refs ===
t.i:1:6: note: not vectorized: loop contains function calls or data references
that cannot be analyzed
t.i:1:6: note: bad data references.
t.i:1:6: note: vectorized 0 loops in function.

Ok, with simply streaming simduid as tree it "works".  Not sure if we want to
stream trees into the CFG section though ... (or if it even really works).

What's the reason that simduid is a tree?

[Bug middle-end/58723] [4.9 Regression] ICE in lto_output_edge, at lto-cgraph.c:300 for OpenMP's simd reduction

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58723

--- Comment #13 from Richard Biener <rguenth at gcc dot gnu.org> ---
Eh.

make check-gcc RUNTESTFLAGS="--target_board=unix/-flto/-ffat-lto-objects
gomp.exp"

FAIL: gcc.dg/gomp/declare-simd-1.c (internal compiler error)
FAIL: gcc.dg/gomp/declare-simd-1.c (test for excess errors)

But otherwise clean.

/space/rguenther/src/svn/trunk/gcc/testsuite/gcc.dg/gomp/declare-simd-1.c:100:1:
internal compiler error: tree code 'omp_clause' is not supported in LTO
streams^M
0xa6dbe4 lto_write_tree^M
        /space/rguenther/src/svn/trunk/gcc/lto-streamer-out.c:376^M

seems like FUNCTION_DECLs now refer to OMP_CLAUSE?  Ah... via attributes :/

Jakub - please add tree streaming support for the relevant required stuff.

[Bug middle-end/58723] [4.9 Regression] ICE in lto_output_edge, at lto-cgraph.c:300 for OpenMP's simd reduction

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58723

--- Comment #14 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #9)
> We fail to stream cfun->has_force_vect_loops.

Note we don't necessarily have to stream that (and has_simduid_loops), the
alternative is to compute it during streaming in the IL - if it sees any
force_vect loop, it can set fun->has_force_vect_loops for the loop, similarly
for non-zero simdlen and fun->has_simduid_loops.  Those two flags are just
(pessimistically correct) flags to avoid scanning the whole IL for it, but LTO
scans the whole IL anyway...

[Bug middle-end/58723] [4.9 Regression] ICE in lto_output_edge, at lto-cgraph.c:300 for OpenMP's simd reduction

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58723

--- Comment #15 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #13)
> Eh.
> 
> make check-gcc RUNTESTFLAGS="--target_board=unix/-flto/-ffat-lto-objects
> gomp.exp"
> 
> FAIL: gcc.dg/gomp/declare-simd-1.c (internal compiler error)
> FAIL: gcc.dg/gomp/declare-simd-1.c (test for excess errors)
> 
> But otherwise clean.
> 
> /space/rguenther/src/svn/trunk/gcc/testsuite/gcc.dg/gomp/declare-simd-1.c:
> 100:1: internal compiler error: tree code 'omp_clause' is not supported in
> LTO streams^M
> 0xa6dbe4 lto_write_tree^M
>         /space/rguenther/src/svn/trunk/gcc/lto-streamer-out.c:376^M
> 
> seems like FUNCTION_DECLs now refer to OMP_CLAUSE?  Ah... via attributes :/
> 
> Jakub - please add tree streaming support for the relevant required stuff.

Yeah, that is the current reason why the new elementals tests to be committed
also fail with LTO.  I'll hack on that.

[Bug middle-end/58723] [4.9 Regression] ICE in lto_output_edge, at lto-cgraph.c:300 for OpenMP's simd reduction

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58723

--- Comment #16 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Wed Nov 27 15:18:23 2013
New Revision: 205447

URL: http://gcc.gnu.org/viewcvs?rev=205447&root=gcc&view=rev
Log:
2013-11-27  Richard Biener  <rguenther@suse.de>

    PR middle-end/58723
    * cgraphbuild.c (build_cgraph_edges): Do not build edges
    for internal calls.
    (rebuild_cgraph_edges): Likewise.
    * ipa-inline-analysis.c (estimate_function_body_sizes):
    Skip internal calls.
    * tree-inline.c (estimate_num_insns): Estimate size of internal
    calls as 0.
    (gimple_expand_calls_inline): Do not try inline-expanding
    internal calls.
    * lto-streamer-in.c (input_cfg): Stream loop safelen,
    force_vect and simduid.
    (input_struct_function_base): Stream has_force_vect_loops
    and has_simduid_loops.
    (input_function): Adjust.
    * lto-streamer-out.c (output_cfg): Stream loop safelen,
    force_vect and simduid.
    (output_struct_function_base): Stream has_force_vect_loops
    and has_simduid_loops.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/cgraphbuild.c
    trunk/gcc/ipa-inline-analysis.c
    trunk/gcc/lto-streamer-in.c
    trunk/gcc/lto-streamer-out.c
    trunk/gcc/tree-inline.c

[Bug middle-end/58723] [4.9 Regression] ICE in lto_output_edge, at lto-cgraph.c:300 for OpenMP's simd reduction

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58723

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|---                         |FIXED

--- Comment #17 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed.  The OMP_CLAUSE issue remains but is really a separate thing.