[Bug tree-optimization/106617] [13 Regression] gcc is very slow at ternary expressions,

["slyfox at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106617

--- Comment #6 from Sergei Trofimovich <slyfox at gcc dot gnu.org> ---
Created attachment 53455
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=53455&action=edit
ring_buffer.c.gz

ring_buffer.c.gz is a preprocessed file from linux-4.19.

$ time gcc-12.1.0 -O2 -c ring_buffer.c -o bug.o

real    0m0,308s
user    0m0,285s
sys     0m0,017s

$ gcc -O2 -c ring_buffer.c -o bug.o

# Runs for minutes, increases RAM usage, never finishes.

perf stats after 3 minutes' run:

  10,16%  cc1               [.] operand_compare::operand_equal_p
   7,38%  cc1               [.] fold_binary_loc
   7,01%  cc1               [.] generic_simplify_453
   5,63%  cc1               [.] generic_simplify_GT_EXPR
   3,72%  cc1               [.] wide_int_binop
   3,42%  cc1               [.] generic_simplify_COND_EXPR
   3,38%  cc1               [.] hash_table<int_cst_hasher, false,
xcallocator>::find_slot_with_hash
   3,04%  cc1               [.] wide_int_to_tree_1
   3,00%  cc1               [.] tree_strip_nop_conversions
   2,82%  cc1               [.] int_const_binop
   2,47%  cc1               [.] get_inner_reference
   2,45%  cc1               [.] fold_build2_loc
   2,23%  cc1               [.] fold_ternary_loc
   2,07%  cc1               [.] tree_strip_sign_nop_conversions
   1,96%  cc1               [.] int_cst_hasher::hash
   1,83%  cc1               [.] ggc_internal_alloc
   1,81%  cc1               [.] fold_relational_const
   1,61%  cc1               [.] wi::fits_to_tree_p<poly_int<1u,
generic_wide_int<wide_int_ref_storage<false, true> > > >
   1,57%  cc1               [.] generic_simplify_155
   1,51%  cc1               [.] operand_equal_p
   1,22%  cc1               [.] dbg_cnt
   1,20%  cc1               [.] element_precision
   1,10%  cc1               [.] ggc_free