[Bug target/113657] New: [14 Regression] ICE Segmentation fault since r14-1187-gd6b756447cd58b

[Bug target/113657] New: [14 Regression] ICE Segmentation fault since r14-1187-gd6b756447cd58b

[mjires at suse dot cz]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113657

            Bug ID: 113657
           Summary: [14 Regression] ICE Segmentation fault since
                    r14-1187-gd6b756447cd58b
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: mjires at suse dot cz
                CC: aoliva at gcc dot gnu.org
  Target Milestone: ---

Compiling reduced testcase gcc.target/aarch64/pr113550.c results in ICE since
r14-1187-gd6b756447cd58b.

$ cat pr113550.c
#pragma GCC target "+ls64"
#pragma GCC aarch64 "arm_acle.h"
__arm_data512_t foo(__arm_data512_t* ptr) { return *ptr; }


$ aarch64-linux-gnu-gcc pr113550.c -mstrict-align
during RTL pass: split5
pr113550.c: In function ‘foo’:
pr113550.c:3:58: internal compiler error: Segmentation fault
    3 | __arm_data512_t foo(__arm_data512_t* ptr) { return *ptr; }
      |                                                          ^
0x178f9de crash_signal
        /home/mjires/git/GCC/master/gcc/toplev.cc:317
0x16f7566 reg_overlap_mentioned_p(rtx_def const*, rtx_def const*)
        /home/mjires/git/GCC/master/gcc/rtlanal.cc:1857
0x267687e gen_split_300(rtx_insn*, rtx_def**)
        /home/mjires/git/GCC/master/gcc/config/aarch64/aarch64-simd.md:8232
0x2a7ffb2 split_71
        /home/mjires/git/GCC/master/gcc/config/aarch64/aarch64-simd.md:8212
0x2a99edf split_131
        /home/mjires/git/GCC/master/gcc/config/aarch64/aarch64.md:875
0x2a9dcf4 split_insns(rtx_def*, rtx_insn*)
        /home/mjires/git/GCC/master/gcc/config/aarch64/aarch64-sve.md:10993
0x117c8db try_split(rtx_def*, rtx_insn*, int)
        /home/mjires/git/GCC/master/gcc/emit-rtl.cc:3941
0x16a3a44 split_insn
        /home/mjires/git/GCC/master/gcc/recog.cc:3405
0x16a3ea6 split_all_insns_noflow()
        /home/mjires/git/GCC/master/gcc/recog.cc:3567
0x16a5ee4 execute
        /home/mjires/git/GCC/master/gcc/recog.cc:4641
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.


$ aarch64-linux-gnu-gcc -v
Using built-in specs.
COLLECT_GCC=aarch64-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/home/mjires/built/master/libexec/gcc/aarch64-linux-gnu/14.0.1/lto-wrapper
Target: aarch64-linux-gnu
Configured with: /home/mjires/git/GCC/master/configure
--prefix=/home/mjires/built/master --target=aarch64-linux-gnu
--disable-bootstrap --enable-languages=c,c++,fortran --disable-multilib
--disable-libsanitizer --enable-checking : (reconfigured)
/home/mjires/git/GCC/master/configure --prefix=/home/mjires/built/master
--target=aarch64-linux-gnu --disable-bootstrap --enable-languages=c,c++,fortran
--disable-multilib --disable-libsanitizer --enable-checking
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 14.0.1 20240129 (experimental) (GCC)

[Bug target/113657] [14 Regression] ICE Segmentation fault with -mstrict-align and __arm_data512_t since r14-1187-gd6b756447cd58b

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113657

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pinskia at gcc dot gnu.org
   Target Milestone|---                         |14.0
            Summary|[14 Regression] ICE         |[14 Regression] ICE
                   |Segmentation fault since    |Segmentation fault with
                   |r14-1187-gd6b756447cd58b    |-mstrict-align and
                   |                            |__arm_data512_t since
                   |                            |r14-1187-gd6b756447cd58b

[Bug target/113657] [14 Regression] ICE Segmentation fault with -mstrict-align and __arm_data512_t since r14-1187-gd6b756447cd58b

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113657

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2024-01-30
             Status|UNCONFIRMED                 |NEW

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Confirmed.

8229                simplify_gen_subreg (TImode, operands[1], V8DImode, offset)

(gdb) p debug_rtx(operands[1])
(mem:V8DI (reg/f:DI 0 x0 [101]) [1 *ptr_2(D)+0 S64 A64])
$4 = void
(gdb) p offset
$5 = 0

That is due to:
/* V8DI mode.  */
VECTOR_MODE_WITH_PREFIX (V, INT, DI, 8, 5);
ADJUST_ALIGNMENT (V8DI, 8);


So maybe for strict alignment, we need to loop using DImode instead of TImode
and hope ldp/stp pass optimizes it back into load/store pairs ...

[Bug target/113657] [14 Regression] ICE Segmentation fault with -mstrict-align and __arm_data512_t since r14-1187-gd6b756447cd58b

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113657

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

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

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
I have a patch.

[Bug target/113657] [14 Regression] ICE Segmentation fault with -mstrict-align and __arm_data512_t since r14-1187-gd6b756447cd58b

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113657

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |patch
                URL|                            |https://gcc.gnu.org/piperma
                   |                            |il/gcc-patches/2024-January
                   |                            |/644464.html

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Patch posted:
https://gcc.gnu.org/pipermail/gcc-patches/2024-January/644464.html

[Bug target/113657] [14 Regression] ICE Segmentation fault with -mstrict-align and __arm_data512_t since r14-1187-gd6b756447cd58b

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113657

--- Comment #4 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The trunk branch has been updated by Andrew Pinski <pinskia@gcc.gnu.org>:

https://gcc.gnu.org/g:dbf847d2c8d1c910948ba34c9338939c67323273

commit r14-8671-gdbf847d2c8d1c910948ba34c9338939c67323273
Author: Andrew Pinski <quic_apinski@quicinc.com>
Date:   Tue Jan 30 00:50:56 2024 -0800

    aarch64: -mstrict-align vs __arm_data512_t [PR113657]

    After r14-1187-gd6b756447cd58b, simplify_gen_subreg can return
    NULL for "unaligned" memory subreg. Since V8DI has an alignment of 8 bytes,
    using TImode causes simplify_gen_subreg to return NULL.
    This fixes the issue by using DImode instead for the loop. And then we will
have
    later on the STP/LDP pass combine it back into STP/LDP if needed.
    Since strict align is less important (usually used for firmware and early
boot only),
    not doing LDP/STP here is ok.

    Built and tested for aarch64-linux-gnu with no regressions.

            PR target/113657

    gcc/ChangeLog:

            * config/aarch64/aarch64-simd.md (split for movv8di):
            For strict aligned mode, use DImode instead of TImode.

    gcc/testsuite/ChangeLog:

            * gcc.target/aarch64/acle/ls64_strict_align.c: New test.

    Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>

[Bug target/113657] [14 Regression] ICE Segmentation fault with -mstrict-align and __arm_data512_t since r14-1187-gd6b756447cd58b

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113657

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

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

--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Fixed.