[Bug lto/96591] New: ICE with -flto=auto and -O1: tree code ‘typename_type’ is not supported in LTO streams

[Bug lto/96591] New: ICE with -flto=auto and -O1: tree code ‘typename_type’ is not supported in LTO streams

[gcc-bugs at marehr dot dialup.fu-berlin.de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96591

            Bug ID: 96591
           Summary: ICE with -flto=auto and -O1: tree code ‘typename_type’
                    is not supported in LTO streams
           Product: gcc
           Version: 10.1.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: lto
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gcc-bugs at marehr dot dialup.fu-berlin.de
                CC: marxin at gcc dot gnu.org
  Target Milestone: ---

Hi gcc-team,

I'm not sure if this is the right component.

The following code:

```c++
template <typename scalar_t, unsigned length>
struct builtin_simd
{
  using type [[gnu::vector_size(sizeof(scalar_t) * length)]] = scalar_t;
};

struct simd_traits
{
  using scalar_type = int;

  template <typename new_scalar_type>
  using rebind = typename builtin_simd<new_scalar_type, 1>::type;
};

template <typename simd_t>
constexpr simd_t fill(typename simd_traits::scalar_type const scalar)
{
  return simd_t{scalar};
}

class Test
{
    using score_type = typename builtin_simd<int, 1>::type;
    score_type data[1]{fill<score_type>(8)};
};

struct TestFactoryBase
{
  virtual Test *CreateTest() = 0;
};

template <class TestClass>
struct TestFactoryImpl : public TestFactoryBase
{
  Test *CreateTest() override { return new TestClass; }
};

void MakeAndRegisterTestInfo(TestFactoryBase *factory);

int main() {
  MakeAndRegisterTestInfo(new TestFactoryImpl<Test>);
}
```

https://godbolt.org/z/55xTod

produces with

> > g++ -O1 -flto=auto ice.cpp
> during IPA pass: pure-const
> ice.cpp:42:1: internal compiler error: tree code ‘typename_type’ is not supported in LTO streams
>    42 | }
>       | ^
> Please submit a full bug report, with preprocessed source if appropriate.
> See <https://bugs.archlinux.org/> for instructions.

that error.

Some notes:
* removing "using rebind = typename builtin_simd<new_scalar_type, 1>::type;" or
* removing "constexpr" from constexpr simd_t fill(typename
simd_traits::scalar_type const scalar) 
will make it compile.

Thank you!

[Bug lto/96591] ICE with -flto=auto and -O1: tree code ‘typename_type’ is not supported in LTO streams

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96591

Martin Liška <marxin at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2020-08-12
           Keywords|                            |needs-bisection
             Status|UNCONFIRMED                 |NEW

--- Comment #1 from Martin Liška <marxin at gcc dot gnu.org> ---
Confirmed, started in between GCC 4.8 and GCC 4.9.

[Bug c++/96591] [8/9/10/11 Regression] ICE with -flto=auto and -O1: tree code ‘typename_type’ is not supported in LTO streams

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96591

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|lto                         |c++
   Target Milestone|---                         |8.5
           Keywords|                            |lto

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
FE trees should not leak into the middle-end so it looks more like a FE issue
to me.  We're chasing TYPE_FIELDS of the context of the scalar_type name
and visiting a TEMPLATE_DECL for 'rebind' in simd_traits.

In the end this might mean free-lang-data doesn't visit DECL_CONTEXT of
the INTEGER_TYPEs TYPE_NAME?  At least I do not see it walking
simd_traits.

It might also be that some intermediate optimization somehow introduces
a reference to this type from nowhere (huh).

[Bug c++/96591] [8/9/10/11 Regression] ICE with -flto=auto and -O1: tree code ‘typename_type’ is not supported in LTO streams

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96591

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at gcc dot gnu.org
           Keywords|needs-bisection             |

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Started with r206639.

[Bug c++/96591] [8/9/10/11 Regression] ICE with -flto=auto and -O1: tree code ‘typename_type’ is not supported in LTO streams

[asolokha at gmx dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96591

Arseny Solokha <asolokha at gmx dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |asolokha at gmx dot com

--- Comment #4 from Arseny Solokha <asolokha at gmx dot com> ---
Is it somehow related to PR83997? Maybe even a duplicate?

[Bug c++/96591] [8/9/10/11 Regression] ICE with -flto=auto and -O1: tree code ‘typename_type’ is not supported in LTO streams

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96591

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

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

[Bug c++/96591] [8/9/10/11 Regression] ICE with -flto=auto and -O1: tree code ‘typename_type’ is not supported in LTO streams

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96591

Jason Merrill <jason at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |jason at gcc dot gnu.org

[Bug lto/96591] [8/9/10/11 Regression] ICE with -flto=auto and -O1: tree code ‘typename_type’ is not supported in LTO streams

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96591

Jason Merrill <jason at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|c++                         |lto
           Assignee|jason at gcc dot gnu.org           |unassigned at gcc dot gnu.org
             Status|ASSIGNED                    |NEW

--- Comment #5 from Jason Merrill <jason at gcc dot gnu.org> ---
(In reply to Arseny Solokha from comment #4)
> Is it somehow related to PR83997? Maybe even a duplicate?

No, not a duplicate.

Reduced a bit more:

struct builtin_simd
{
  using type [[gnu::vector_size(sizeof(scalar_t) * length)]] = scalar_t;
};

struct simd_traits
{
  using scalar_type = int;

  template <typename X>
  using rebind = typename X::type;
};

template <typename simd_t>
constexpr simd_t fill(typename simd_traits::scalar_type const scalar)
{
  return simd_t{scalar};
}

using score_type = typename builtin_simd<int, 1>::type;
// Uncommenting this makes it work:
// const simd_traits::scalar_type n = 8;
score_type data[1]{fill<score_type>(8)};

The difference from uncommenting that line seems to be that then
free_lang_data_in_type is called for simd_traits::scalar_type.  So the problem
seems to be that find_decls_types isn't finding scalar_type in the vector in
the array.  So changing component to LTO and unassigning myself.  Feel free to
change it back if it seems appropriate.

[Bug lto/96591] [8/9/10/11 Regression] ICE with -flto=auto and -O1: tree code ‘typename_type’ is not supported in LTO streams

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96591

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |rguenth at gcc dot gnu.org

--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
I will have a look.

[Bug lto/96591] [8/9/10/11 Regression] ICE with -flto=auto and -O1: tree code ‘typename_type’ is not supported in LTO streams

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96591

--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> ---
So the type is refered to by constant 8 which is refered to by a VECTOR_CST
{ 8 } which is refered to by

# .MEM_4 = VDEF <.MEM_2>
MEM[(struct Test *)_3].data[0] = { 8 };

and while walk_tree walks CTOR elements for VECTOR_CST it does nothing:

  switch (code)
    {
    case ERROR_MARK:
    case IDENTIFIER_NODE:
    case INTEGER_CST:
    case REAL_CST:
    case FIXED_CST:
    case VECTOR_CST:
    case STRING_CST:
    case BLOCK:
    case PLACEHOLDER_EXPR:
    case SSA_NAME:
    case FIELD_DECL:
    case RESULT_DECL:
      /* None of these have subtrees other than those already walked
         above.  */
      break;

which is eventually true since we expect the element type of a VECTOR_CST
to match that of the vector element type.  _But_ - we're forcing a vector
element type to be the main variant / canonical type:

 <vector_cst 0x7ffff66d9c30
    type <vector_type 0x7ffff66dedc8
        type <integer_type 0x7ffff65885e8 int public type_6 SI
            size <integer_cst 0x7ffff658b108 constant 32>
            unit-size <integer_cst 0x7ffff658b120 constant 4>
            align:32 warn_if_not_align:0 symtab:0 alias-set 2 canonical-type
0x7ffff65885e8 precision:32 min <integer_cst 0x7ffff658b0c0 -2147483648> max
<integer_cst 0x7ffff658b0d8 2147483647>
            pointer_to_this <pointer_type 0x7ffff65909d8>>
        type_6 SI size <integer_cst 0x7ffff658b108 32> unit-size <integer_cst
0x7ffff658b120 4>
        align:32 warn_if_not_align:0 symtab:0 alias-set -1 canonical-type
0x7ffff66dedc8 nunits:1>
    constant npatterns:1 nelts-per-pattern:1
    elt:0:  <integer_cst 0x7ffff66d9be8 type <integer_type 0x7ffff66de3f0
scalar_type> constant 8>>
(gdb) p ((tree)0x7ffff66de3f0)->type_common.canonical 
$134 = <integer_type 0x7ffff65885e8 int>
(gdb) p ((tree)0x7ffff66de3f0)->type_common.main_variant 
$135 = <integer_type 0x7ffff65885e8 int>

where we build this via

#0  0x0000000001cf4437 in tree_vector_builder::build (this=0x7fffffffbfe0)
    at /home/rguenther/src/gcc3/gcc/tree-vector-builder.c:44
#1  0x0000000001d112c9 in build_vector_from_ctor (
    type=<vector_type 0x7ffff66dedc8>, v=0x7ffff66e72d0 = {...})
    at /home/rguenther/src/gcc3/gcc/tree.c:1969
#2  0x00000000012cccda in fold (expr=<constructor 0x7ffff66d9c18>)
    at /home/rguenther/src/gcc3/gcc/fold-const.c:13383
#3  0x0000000000b0b893 in cxx_eval_bare_aggregate (ctx=0x7fffffffc290, 
    t=<constructor 0x7ffff66d9c18>, lval=false, non_constant_p=0x7fffffffd1bf, 
    overflow_p=0x7fffffffd1be)
    at /home/rguenther/src/gcc3/gcc/cp/constexpr.c:4438
#4  0x0000000000b14c6b in cxx_eval_constant_expression (ctx=0x7fffffffc610, 
    t=<constructor 0x7ffff66d9bd0>, lval=false, non_constant_p=0x7fffffffd1bf, 
    overflow_p=0x7fffffffd1be, jump_target=0x0)
    at /home/rguenther/src/gcc3/gcc/cp/constexpr.c:6591

it's tempting to try force the cached integer constants to be always
unqualified so that only the TYPE_MAIN_VARIANT has TYPE_CACHED_VALUES
and we save memory.  The constant is built via

(gdb) bt
#0  0x0000000001d0fcf1 in cache_wide_int_in_type_cache (
    type=<integer_type 0x7ffff66de3f0 scalar_type>, cst=..., slot=9, 
    max_slots=252) at /home/rguenther/src/gcc3/gcc/tree.c:1535
#1  0x0000000001d1020d in wide_int_to_tree_1 (
    type=<integer_type 0x7ffff66de3f0 scalar_type>, pcst=...)
    at /home/rguenther/src/gcc3/gcc/tree.c:1649
#2  0x0000000001d10878 in wide_int_to_tree (
    type=<integer_type 0x7ffff66de3f0 scalar_type>, value=...)
    at /home/rguenther/src/gcc3/gcc/tree.c:1756
#3  0x0000000001d0f918 in force_fit_type (
    type=<integer_type 0x7ffff66de3f0 scalar_type>, cst=..., overflowable=1, 
    overflowed=false) at /home/rguenther/src/gcc3/gcc/tree.c:1474
#4  0x00000000012969cb in fold_convert_const_int_from_int (
    type=<integer_type 0x7ffff66de3f0 scalar_type>, 
    arg1=<integer_cst 0x7ffff66d9618>)
    at /home/rguenther/src/gcc3/gcc/fold-const.c:2000
#5  0x00000000012988b6 in fold_convert_const (code=NOP_EXPR, 
    type=<integer_type 0x7ffff66de3f0 scalar_type>, 
    arg1=<integer_cst 0x7ffff66d9618>)
    at /home/rguenther/src/gcc3/gcc/fold-const.c:2276
#6  0x0000000001299214 in fold_convert_loc (loc=0, 
    type=<integer_type 0x7ffff66de3f0 scalar_type>, 
    arg=<integer_cst 0x7ffff66d9618>)
--Type <RET> for more, q to quit, c to continue without paging--
    at /home/rguenther/src/gcc3/gcc/fold-const.c:2418
#7  0x0000000000b714fa in cp_fold_convert (
    type=<integer_type 0x7ffff66de3f0 scalar_type>, 
    expr=<integer_cst 0x7ffff66d9618>)
    at /home/rguenther/src/gcc3/gcc/cp/cvt.c:629
#8  0x0000000000aff0d3 in adjust_temp_type (
    type=<integer_type 0x7ffff66de888 scalar_type>, 
    temp=<integer_cst 0x7ffff66d9618>)
    at /home/rguenther/src/gcc3/gcc/cp/constexpr.c:1501
#9  0x0000000000aff651 in cxx_bind_parameters_in_call (ctx=0x7fffffffd0a0, 
    t=<call_expr 0x7ffff6577150>, new_call=0x7fffffffccc0, 
    non_constant_p=0x7fffffffd1bf, overflow_p=0x7fffffffd1be, 
    non_constant_args=0x7fffffffcc7f)
    at /home/rguenther/src/gcc3/gcc/cp/constexpr.c:1611
#10 0x0000000000b0404c in cxx_eval_call_expression (ctx=0x7fffffffd0a0, 
    t=<call_expr 0x7ffff6577150>, lval=false, non_constant_p=0x7fffffffd1bf, 
    overflow_p=0x7fffffffd1be)
    at /home/rguenther/src/gcc3/gcc/cp/constexpr.c:2536
#11 0x0000000000b13215 in cxx_eval_constant_expression (ctx=0x7fffffffd0a0, 
    t=<call_expr 0x7ffff6577150>, lval=false, non_constant_p=0x7fffffffd1bf, 
    overflow_p=0x7fffffffd1be, jump_target=0x0)
    at /home/rguenther/src/gcc3/gcc/cp/constexpr.c:6134

where the constant is first built in the "correct" type and then
converted via adjust_temp_type which does

1499      /* Now we know we're dealing with a scalar, and a prvalue of
non-class
1500         type is cv-unqualified.  */
1501      return cp_fold_convert (cv_unqualified (type), temp);

but that cv_unqualified doesn't produce the main variant.

Now, as a fact walk_tree _does_ walk COMPLEX_CST components so the "obvious"
fix here would be to change it to also walk VECTOR_CST components.  So that's
what I'm going to try first.

[Bug lto/96591] [8/9/10/11 Regression] ICE with -flto=auto and -O1: tree code ‘typename_type’ is not supported in LTO streams

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96591

--- Comment #8 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Richard Biener <rguenth@gcc.gnu.org>:

https://gcc.gnu.org/g:d4536e431316b4568e236afd7a6017e5efd1b0a1

commit r11-7134-gd4536e431316b4568e236afd7a6017e5efd1b0a1
Author: Richard Biener <rguenther@suse.de>
Date:   Mon Feb 8 09:52:56 2021 +0100

    lto/96591 - walk VECTOR_CST elements in walk_tree

    This implements walking of VECTOR_CST elements in walk_tree, mimicing
    the walk of COMPLEX_CST elements.  Without this free-lang-data fails
    to see some types in case they are only refered to via tree constants
    used only as VECTOR_CST elements.

    2021-02-08  Richard Biener  <rguenther@suse.de>

            PR lto/96591
            * tree.c (walk_tree_1): Walk VECTOR_CST elements.

            * g++.dg/lto/pr96591_0.C: New testcase.

[Bug lto/96591] [8/9/10 Regression] ICE with -flto=auto and -O1: tree code ‘typename_type’ is not supported in LTO streams

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96591

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|                            |11.0
            Summary|[8/9/10/11 Regression] ICE  |[8/9/10 Regression] ICE
                   |with -flto=auto and -O1:    |with -flto=auto and -O1:
                   |tree code ‘typename_type’   |tree code ‘typename_type’
                   |is not supported in LTO     |is not supported in LTO
                   |streams                     |streams

--- Comment #9 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed on trunk sofar.

[Bug lto/96591] [8/9/10 Regression] ICE with -flto=auto and -O1: tree code ‘typename_type’ is not supported in LTO streams

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96591

--- Comment #10 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-10 branch has been updated by Richard Biener
<rguenth@gcc.gnu.org>:

https://gcc.gnu.org/g:277fbd0748279cfcb241eff7c4d5ef93afbfbafd

commit r10-9526-g277fbd0748279cfcb241eff7c4d5ef93afbfbafd
Author: Richard Biener <rguenther@suse.de>
Date:   Mon Feb 8 09:52:56 2021 +0100

    lto/96591 - walk VECTOR_CST elements in walk_tree

    This implements walking of VECTOR_CST elements in walk_tree, mimicing
    the walk of COMPLEX_CST elements.  Without this free-lang-data fails
    to see some types in case they are only refered to via tree constants
    used only as VECTOR_CST elements.

    2021-02-08  Richard Biener  <rguenther@suse.de>

            PR lto/96591
            * tree.c (walk_tree_1): Walk VECTOR_CST elements.

            * g++.dg/lto/pr96591_0.C: New testcase.

    (cherry picked from commit d4536e431316b4568e236afd7a6017e5efd1b0a1)

[Bug lto/96591] [8/9 Regression] ICE with -flto=auto and -O1: tree code ‘typename_type’ is not supported in LTO streams

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96591

--- Comment #11 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-9 branch has been updated by Richard Biener
<rguenth@gcc.gnu.org>:

https://gcc.gnu.org/g:c0ae84d67a61512ec36d5c82ae52090c4b6440d1

commit r9-9341-gc0ae84d67a61512ec36d5c82ae52090c4b6440d1
Author: Richard Biener <rguenther@suse.de>
Date:   Mon Feb 8 09:52:56 2021 +0100

    lto/96591 - walk VECTOR_CST elements in walk_tree

    This implements walking of VECTOR_CST elements in walk_tree, mimicing
    the walk of COMPLEX_CST elements.  Without this free-lang-data fails
    to see some types in case they are only refered to via tree constants
    used only as VECTOR_CST elements.

    2021-02-08  Richard Biener  <rguenther@suse.de>

            PR lto/96591
            * tree.c (walk_tree_1): Walk VECTOR_CST elements.

            * g++.dg/lto/pr96591_0.C: New testcase.

    (cherry picked from commit d4536e431316b4568e236afd7a6017e5efd1b0a1)

[Bug lto/96591] [8 Regression] ICE with -flto=auto and -O1: tree code ‘typename_type’ is not supported in LTO streams

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96591

--- Comment #12 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-8 branch has been updated by Richard Biener
<rguenth@gcc.gnu.org>:

https://gcc.gnu.org/g:d0669d6ac82726cd751b73c7fb04194b446dfd49

commit r8-10921-gd0669d6ac82726cd751b73c7fb04194b446dfd49
Author: Richard Biener <rguenther@suse.de>
Date:   Mon Feb 8 09:52:56 2021 +0100

    lto/96591 - walk VECTOR_CST elements in walk_tree

    This implements walking of VECTOR_CST elements in walk_tree, mimicing
    the walk of COMPLEX_CST elements.  Without this free-lang-data fails
    to see some types in case they are only refered to via tree constants
    used only as VECTOR_CST elements.

    2021-02-08  Richard Biener  <rguenther@suse.de>

            PR lto/96591
            * tree.c (walk_tree_1): Walk VECTOR_CST elements.

            * g++.dg/lto/pr96591_0.C: New testcase.

    (cherry picked from commit d4536e431316b4568e236afd7a6017e5efd1b0a1)

[Bug lto/96591] [8 Regression] ICE with -flto=auto and -O1: tree code ‘typename_type’ is not supported in LTO streams

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96591

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to fail|                            |8.4.0
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED
      Known to work|                            |8.4.1

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