[Bug tree-optimization/126404] [16/17 Regression] ICE at -O2/3 on aarch64 during GIMPLE pass: vect

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126404

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2026-07-25
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW

--- Comment #1 from Drea Pinski <pinskia at gcc dot gnu.org> ---
[pinskia@cfarm185 gcc]$ ../stage1-gcc/cc1 t.c -O2
 f13f14
Analyzing compilation unit
Performing interprocedural optimizations
 <*free_lang_data> {heap 1280k} <visibility> {heap 1280k} <build_ssa_passes>
{heap 1280k} <targetclone> {heap 1472k} <opt_local_passes> {heap 1472k}
<remove_symbols> {heap 2048k} <targetclone> {heap 2048k} <free-fnsummary> {heap
2048k} <increase_alignment> {heap 2048k}Streaming LTO
 <whole-program> {heap 2048k} <profile_estimate> {heap 2048k} <icf> {heap
2048k} <devirt> {heap 2048k} <cp> {heap 2048k} <sra> {heap 2048k} <fnsummary>
{heap 2048k} <inline> {heap 2048k} <pure-const> {heap 2048k} <modref> {heap
2048k} <free-fnsummary> {heap 2048k} <static-var> {heap 2048k} <single-use>
{heap 2048k} <comdats> {heap 2048k}Assembling functions:
 <simdclone> {heap 2048k} f13f14during GIMPLE pass: vect
t.c: In function ‘f13f14’:
t.c:3:6: internal compiler error: Segmentation fault
    3 | void f13f14()
      |      ^~~~~~
0x3d68abf internal_error(char const*, ...)
        /home/pinskia/src/upstream/gcc/gcc/diagnostic-global-context.cc:787
0x1c01bdf crash_signal
        /home/pinskia/src/upstream/gcc/gcc/toplev.cc:325
0x1fd2ce8 vec<_stmt_vec_info*, va_heap, vl_embed>::operator[](unsigned int)
        /home/pinskia/src/upstream/gcc/gcc/vec.h:911
0x1fd06d7 vec<_stmt_vec_info*, va_heap, vl_ptr>::operator[](unsigned int)
        /home/pinskia/src/upstream/gcc/gcc/vec.h:1610
0x20223af vect_analyze_slp_reduc_chain
        /home/pinskia/src/upstream/gcc/gcc/tree-vect-slp.cc:4430
0x2023b9f vect_analyze_slp_reduction
        /home/pinskia/src/upstream/gcc/gcc/tree-vect-slp.cc:4820
0x2024857 vect_analyze_slp_reductions
        /home/pinskia/src/upstream/gcc/gcc/tree-vect-slp.cc:5068
0x2027cdf vect_analyze_slp(vec_info*, unsigned int, bool)
        /home/pinskia/src/upstream/gcc/gcc/tree-vect-slp.cc:5986
0x1fde003 vect_analyze_loop_2
        /home/pinskia/src/upstream/gcc/gcc/tree-vect-loop.cc:2289
0x1fdfa63 vect_analyze_loop_1
        /home/pinskia/src/upstream/gcc/gcc/tree-vect-loop.cc:2823
0x1fe0467 vect_analyze_loop(loop*, gimple*, vec_info_shared*)
        /home/pinskia/src/upstream/gcc/gcc/tree-vect-loop.cc:3004
0x206018f try_vectorize_loop_1
        /home/pinskia/src/upstream/gcc/gcc/tree-vectorizer.cc:1100
0x20606a7 try_vectorize_loop
        /home/pinskia/src/upstream/gcc/gcc/tree-vectorizer.cc:1218
0x206092b execute
        /home/pinskia/src/upstream/gcc/gcc/tree-vectorizer.cc:1335
../stage1-gcc/cc1 t.c -O2
Please submit a full bug report, with preprocessed source (by using
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Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.


#2  0x00000000020223b0 in vect_analyze_slp_reduc_chain (vinfo=0x53d78c0,
bst_map=0x554c1f0, scalar_stmt=0x554cce0, max_tree_size=9,
limit=0xffffffffcaec) at
/home/pinskia/src/upstream/gcc/gcc/tree-vect-slp.cc:4430
4430      stmt_vec_info reduc_scalar_stmt = scalar_stmts[0];
(gdb) l
4425      while (!is_a <gphi *> (STMT_VINFO_STMT (next_stmt)));
4426      if (fail)
4427        return false;
4428
4429      /* Remember a stmt with the actual reduction operation.  */
4430      stmt_vec_info reduc_scalar_stmt = scalar_stmts[0];
4431
4432      /* When the SSA def chain through reduc-idx does not form a natural
4433         reduction chain try to linearize an associative operation
manually.  */
4434      if (scalar_stmts.length () == 1
(gdb) p scalar_stmts
$2 = {m_vec = 0x0}