[Bug tree-optimization/116628] New: [15 Regression] ICE in vect_analyze_loop_1 on aarch64 with -Ofast in TSVC

[Bug tree-optimization/116628] New: [15 Regression] ICE in vect_analyze_loop_1 on aarch64 with -Ofast in TSVC

[ktkachov at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116628

            Bug ID: 116628
           Summary: [15 Regression] ICE in vect_analyze_loop_1 on aarch64
                    with -Ofast in TSVC
           Product: gcc
           Version: 15.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ktkachov at gcc dot gnu.org
  Target Milestone: ---
            Target: aarch64

The testcase is reduced from TSVC:

typedef float c;
c a[2000], b[0];
void d() {
  for (int e = 0; e < 2000; e++)
    if (b[e])
      a[e] = b[e];
}

ICEs with -Ofast -mcpu=neoverse-v2
during GIMPLE pass: vect
tsvc.i: In function ‘d’:
tsvc.i:3:6: internal compiler error: in vect_analyze_loop_1, at
tree-vect-loop.cc:3481
    3 | void d() {
      |      ^
0x21d897b internal_error(char const*, ...)
        $SRC/gcc/diagnostic-global-context.cc:492
0x7d8813 fancy_abort(char const*, int, char const*)
        $SRC/gcc/diagnostic.cc:1658
0x12dfaef vect_analyze_loop_1
        $SRC/gcc/tree-vect-loop.cc:3481
0x12e03ab vect_analyze_loop(loop*, vec_info_shared*)
        $SRC/gcc/tree-vect-loop.cc:3682
0x13256b7 try_vectorize_loop_1
        $SRC/gcc/tree-vectorizer.cc:1068
0x13256b7 try_vectorize_loop
        $SRC/gcc/tree-vectorizer.cc:1184
0x1325f87 execute
        $SRC/gcc/tree-vectorizer.cc:1300
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.

[Bug tree-optimization/116628] [15 Regression] ICE in vect_analyze_loop_1 on aarch64 with -Ofast in TSVC

[ktkachov at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116628

ktkachov at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|                            |14.2.0
      Known to fail|                            |15.0
   Target Milestone|---                         |15.0

[Bug tree-optimization/116628] [15 Regression] ICE in vect_analyze_loop_1 on aarch64 with -Ofast in TSVC

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116628

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
What revision/commit id are you using? Is it before or after  r15-3411 ?

[Bug tree-optimization/116628] [15 Regression] ICE in vect_analyze_loop_1 on aarch64 with -Ofast in TSVC

[ktkachov at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116628

--- Comment #2 from ktkachov at gcc dot gnu.org ---
(In reply to Andrew Pinski from comment #1)
> What revision/commit id are you using? Is it before or after  r15-3411 ?

It's a fairly fresh g:6a1a856ba78589f7f5285b00ecd40ba2bbeef8b0

[Bug tree-optimization/116628] [15 Regression] ICE in vect_analyze_loop_1 on aarch64 with -Ofast in TSVC

[tnfchris at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116628

--- Comment #3 from Tamar Christina <tnfchris at gcc dot gnu.org> ---
Still seems to ICE after that commit on last night's trunk

https://godbolt.org/z/GnYT7Kx46

[Bug tree-optimization/116628] [15 Regression] ICE in vect_analyze_loop_1 on aarch64 with -Ofast in TSVC

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116628

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2024-09-06
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed.  The ICE means we've "fatally" failed to analyze an epilogue which
we do not expect.

t.c:4:21: note:   worklist: examine stmt: .MASK_STORE (&a[e_10], 8B, _9 != 0,
_1);
t.c:4:21: note:   vect_is_simple_use: operand _9 != 0, type of def: unknown
t.c:4:21: missed:   Unsupported pattern.

possibly the embedded _9 != 0 is the problem?

t.c:4:21: note:   vect_recog_bool_pattern: detected: _ifc__24 = _9 ? _1 :
_ifc__22;
t.c:4:21: note:   bool pattern recognized: patt_8 = _9 != 0 ? _1 : _ifc__22;
t.c:4:21: note:   vect_recog_cond_store_pattern: detected: a[e_10] = _ifc__24;
t.c:4:21: note:   cond_store pattern recognized: .MASK_STORE (&a[e_10], 8B, _9
!= 0, _1);

[Bug tree-optimization/116628] [15 Regression] ICE in vect_analyze_loop_1 on aarch64 with -Ofast in TSVC

[tnfchris at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116628

--- Comment #5 from Tamar Christina <tnfchris at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #4)
> Confirmed.  The ICE means we've "fatally" failed to analyze an epilogue
> which we do not expect.
> 
> t.c:4:21: note:   worklist: examine stmt: .MASK_STORE (&a[e_10], 8B, _9 !=
> 0, _1);
> t.c:4:21: note:   vect_is_simple_use: operand _9 != 0, type of def: unknown
> t.c:4:21: missed:   Unsupported pattern.
> 
> possibly the embedded _9 != 0 is the problem?
> 
> t.c:4:21: note:   vect_recog_bool_pattern: detected: _ifc__24 = _9 ? _1 :
> _ifc__22;
> t.c:4:21: note:   bool pattern recognized: patt_8 = _9 != 0 ? _1 : _ifc__22;
> t.c:4:21: note:   vect_recog_cond_store_pattern: detected: a[e_10] =
> _ifc__24;
> t.c:4:21: note:   cond_store pattern recognized: .MASK_STORE (&a[e_10], 8B,
> _9 != 0, _1);

Hmmm if so https://gcc.gnu.org/pipermail/gcc-patches/2024-September/662146.html
should fix it?

[Bug tree-optimization/116628] [15 Regression] ICE in vect_analyze_loop_1 on aarch64 with -Ofast in TSVC

[tnfchris at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116628

Tamar Christina <tnfchris at gcc dot gnu.org> changed:

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

--- Comment #6 from Tamar Christina <tnfchris at gcc dot gnu.org> ---
I'll take this one then.

[Bug tree-optimization/116628] [15 Regression] ICE in vect_analyze_loop_1 on aarch64 with -Ofast in TSVC

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116628

--- Comment #7 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Tamar Christina <tnfchris@gcc.gnu.org>:

https://gcc.gnu.org/g:2c4438d39156493b5b382eb48b1f884ca5ab7ed4

commit r15-3518-g2c4438d39156493b5b382eb48b1f884ca5ab7ed4
Author: Tamar Christina <tamar.christina@arm.com>
Date:   Fri Sep 6 14:05:43 2024 +0100

    middle-end: check that the lhs of a COND_EXPR is an SSA_NAME in cond_store
recognition [PR116628]

    Because the vect_recog_bool_pattern can at the moment still transition
    out of GIMPLE and back into GENERIC the vect_recog_cond_store_pattern can
    end up using an expression as a mask rather than an SSA_NAME.

    This adds an explicit check that we have a mask and not an expression.

    gcc/ChangeLog:

            PR tree-optimization/116628
            * tree-vect-patterns.cc (vect_recog_cond_store_pattern): Add
SSA_NAME
            check on expression.

    gcc/testsuite/ChangeLog:

            PR tree-optimization/116628
            * gcc.dg/vect/pr116628.c: New test.

[Bug tree-optimization/116628] [15 Regression] ICE in vect_analyze_loop_1 on aarch64 with -Ofast in TSVC

[tnfchris at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116628

Tamar Christina <tnfchris at gcc dot gnu.org> changed:

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

--- Comment #8 from Tamar Christina <tnfchris at gcc dot gnu.org> ---
Fixed, thanks for the report!

[Bug tree-optimization/116628] [15 Regression] ICE in vect_analyze_loop_1 on aarch64 with -Ofast in TSVC

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116628

--- Comment #9 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Tamar Christina <tnfchris@gcc.gnu.org>:

https://gcc.gnu.org/g:0189ab205aa86b8e67ae982294f0fe58aa9c4774

commit r15-3738-g0189ab205aa86b8e67ae982294f0fe58aa9c4774
Author: Tamar Christina <tamar.christina@arm.com>
Date:   Fri Sep 20 17:01:39 2024 +0100

    testsuite: Update commandline for PR116628.c to use neoverse-v2 [PR116628]

    The testcase for this tests needs Neoverse V2 to be used
    since due to costing the other cost models don't pick this
    particular SVE mode.

    committed as obvious.

    Thanks,
    Tamar

    gcc/testsuite/ChangeLog:

            PR tree-optimization/116628
            * gcc.dg/vect/pr116628.c: Update cmdline.