[Bug tree-optimization/112673] New: [14 Regression] ICE verify_gimple failed since r14-5557-g6dd4c703be17fa

[Bug tree-optimization/112673] New: [14 Regression] ICE verify_gimple failed since r14-5557-g6dd4c703be17fa

[mjires at suse dot cz]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112673

            Bug ID: 112673
           Summary: [14 Regression] ICE verify_gimple failed since
                    r14-5557-g6dd4c703be17fa
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: mjires at suse dot cz
                CC: jakub at redhat dot com
  Target Milestone: ---

Compiling pr112566-2.c from testsuite.
Bisection points to r14-5557-g6dd4c703be17fa, which also introduced this test.

$ gcc pr112566-2.c -Ofast -mf16c
pr112566-2.c: In function ‘corge’:
pr112566-2.c:10:5: error: ‘bit_field_ref’ of non-mode-precision operand
   10 | int corge (_BitInt(256) x) { return __builtin_ctzg ((unsigned
_BitInt(512)) x); }
      |     ^~~~~
_18 = BIT_FIELD_REF <x_35(D), 64, 64>;
pr112566-2.c:10:5: error: ‘bit_field_ref’ of non-mode-precision operand
_1 = BIT_FIELD_REF <x_35(D), 64, 128>;
pr112566-2.c:10:5: error: ‘bit_field_ref’ of non-mode-precision operand
_38 = BIT_FIELD_REF <x_35(D), 64, 192>;
during GIMPLE pass: forwprop
pr112566-2.c:10:5: internal compiler error: verify_gimple failed
0x105854d verify_gimple_in_cfg(function*, bool, bool)
        /home/mjires/git/GCC/master/gcc/tree-cfg.cc:5662
0xee86b4 execute_function_todo
        /home/mjires/git/GCC/master/gcc/passes.cc:2088
0xee8c0e execute_todo
        /home/mjires/git/GCC/master/gcc/passes.cc:2142
Please submit a full bug report, with preprocessed source (by using
-freport-bug).
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.

$ gcc -v
Using built-in specs.
COLLECT_GCC=/home/mjires/built/master/bin/gcc
COLLECT_LTO_WRAPPER=/home/mjires/built/master/libexec/gcc/x86_64-pc-linux-gnu/14.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /home/mjires/git/GCC/master/configure
--prefix=/home/mjires/built/master --disable-bootstrap --enable-checking
--enable-languages=c,c++,fortran,lto
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 14.0.0 20231122 (experimental) (GCC)

[Bug tree-optimization/112673] [14 Regression] ICE verify_gimple failed since r14-5557-g6dd4c703be17fa

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112673

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |14.0

[Bug tree-optimization/112673] [14 Regression] ICE verify_gimple failed since r14-5557-g6dd4c703be17fa

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112673

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|jakub at redhat dot com            |jakub at gcc dot gnu.org

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
I think this is a match.pd problem.
First vectorizer vectorizes the
  _18 = VIEW_CONVERT_EXPR<unsigned long[4]>(x)[_16];
  bitint.2[_16] = _18;
...
copying loop, before forwprop4 we have
  vect__18.6_34 = VIEW_CONVERT_EXPR<vector(4) unsigned long>(x_35(D));
  _8 = BIT_FIELD_REF <vect__18.6_34, 64, 0>;
...
  _18 = BIT_FIELD_REF <vect__18.6_34, 64, 64>;
...
etc., which I think is valid, but during forwprop4 the
(simplify
 (BIT_FIELD_REF (view_convert @0) @1 @2)
 (BIT_FIELD_REF @0 @1 @2))
simplification kicks in and we create invalid
  _18 = BIT_FIELD_REF <x_35(D), 64, 64>;
out of it, because x has _BitInt(256) type and so doesn't have mode precision.
tree-cfg.cc checking for BIT_FIELD_REF diagnoses:
          if (INTEGRAL_TYPE_P (TREE_TYPE (op))
              && !type_has_mode_precision_p (TREE_TYPE (op)))
            {
              error ("%qs of non-mode-precision operand", code_name);
              return true;
            }
so maybe
--- gcc/match.pd.jj     2023-11-17 15:10:43.306043972 +0100
+++ gcc/match.pd        2023-11-23 18:09:22.538414897 +0100
@@ -8285,7 +8285,9 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)

 (simplify
  (BIT_FIELD_REF (view_convert @0) @1 @2)
- (BIT_FIELD_REF @0 @1 @2))
+ (if (! INTEGRAL_TYPE_P (TREE_TYPE (@0))
+      || type_has_mode_precision_p (TREE_TYPE (@0)))
+  (BIT_FIELD_REF @0 @1 @2)))

 (simplify
  (BIT_FIELD_REF @0 @1 integer_zerop)

[Bug tree-optimization/112673] [14 Regression] ICE verify_gimple failed since r14-5557-g6dd4c703be17fa

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112673

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2023-11-23
           Assignee|unassigned at gcc dot gnu.org      |jakub at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Created attachment 56675
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=56675&action=edit
gcc14-pr112673.patch

Full untested patch.

[Bug tree-optimization/112673] [14 Regression] ICE verify_gimple failed since r14-5557-g6dd4c703be17fa

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112673

--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jakub Jelinek <jakub@gcc.gnu.org>:

https://gcc.gnu.org/g:eebcad0ac22010fc59de9d856bb02017fccab282

commit r14-5819-geebcad0ac22010fc59de9d856bb02017fccab282
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Fri Nov 24 11:32:28 2023 +0100

    match.pd: Avoid simplification into invalid BIT_FIELD_REFs [PR112673]

    The following testcase is lowered by the bitint lowering pass, then
    vectorizer vectorizes one of the loops in it, so we have
      vect__18.6_34 = VIEW_CONVERT_EXPR<vector(4) unsigned long>(x_35(D));
      _8 = BIT_FIELD_REF <vect__18.6_34, 64, 0>;
    ...
      _18 = BIT_FIELD_REF <vect__18.6_34, 64, 64>;
    etc. where x_35(D) is _BitInt(256) argument.  That is valid BIT_FIELD_REF,
    the first argument is a vector and it extracts the vector elements from it.
    Then comes forwprop4 and simplifies that using match.pd into
      _8 = (unsigned long) x_35(D);
    ...
      _18 = BIT_FIELD_REF <x_35(D), 64, 64>;
    and tree-cfg verification ICEs on the latter (though, even the first cast
    is kind of undesirable after bitint lowering, we want large/huge bitints
    lowered).  The ICE is because if BIT_FIELD_REFs first argument has
    INTEGRAL_TYPE_P, we require type_has_mode_precision_p, but that is not the
    case of _BitInt(256), it has BLKmode.

    The following patch fixes it by doing the BIT_FIELD_REF with VCE to
    BIT_FIELD_REF simplification only if the result is valid.

    2023-11-24  Jakub Jelinek  <jakub@redhat.com>

            PR tree-optimization/112673
            * match.pd (bit_field_ref (vce @0) -> bit_field_ref @0): Only
simplify
            if either @0 doesn't have scalar integral type or if it has mode
            precision.

            * gcc.dg/pr112673.c: New test.

[Bug tree-optimization/112673] [14 Regression] ICE verify_gimple failed since r14-5557-g6dd4c703be17fa

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112673

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

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

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Should be fixed now.