Numo::DFloat is much slower than the old narray library's NVector

[mame]

I found that x.inplace + i is much slower than x.add!(i).

$ time ruby -rnarray -e 'x = NVector[0.0, 0.0, 0.0]; i = NVector[1.0, 1.0, 1.0]; 10000000.times { x.add!(i) }; p x'
NVector.float(3):
[ 1.0e+07, 1.0e+07, 1.0e+07 ]

real    0m1.190s
user    0m1.169s
sys     0m0.020s

$ time ruby -rnumo/narray -e 'x = Numo::DFloat[0.0, 0.0, 0.0]; i = Numo::DFloat[1.0, 1.0, 1.0]; xi = x.inplace; 10000000.times { xi + i }; p x'
Numo::DFloat#shape=[3]
[1e+07, 1e+07, 1e+07]

real    0m6.467s
user    0m6.454s
sys     0m0.012s

I have no idea if this is a bug, but @mrkn asked me to create a ticket.

[mrkn]

I checked the reason of this performance issue by perf.
As a result, the main bottleneck is rb_check_typeddata.

# To display the perf.data header info, please use --header/--header-only options.
#
#
# Total Lost Samples: 0
#
# Samples: 4K of event 'cycles'
# Event count (approx.): 4044660818
#
# Overhead  Command          Shared Object       Symbol
# ........  ...............  ..................  ....................................................
#
     7.02%  ruby             libruby.so.3.0.2    [.] rb_check_typeddata
     4.35%  swapper          [kernel.kallsyms]   [k] 0xffffffff8f3faac9
     3.88%  ruby             narray.so           [.] ndloop_run
     3.65%  ruby             narray.so           [.] ndloop_set_stepidx.isra.0
     3.53%  ruby             narray.so           [.] ndloop_init_args.isra.0
     3.45%  ruby             libruby.so.3.0.2    [.] rb_obj_is_kind_of
     2.80%  ruby             libruby.so.3.0.2    [.] rb_typeddata_inherited_p
     2.69%  ruby             narray.so           [.] ndloop_alloc
     2.60%  ruby             libruby.so.3.0.2    [.] gc_sweep_step
     2.60%  ruby             narray.so           [.] ndloop_set_output_narray
     2.57%  ruby             libruby.so.3.0.2    [.] vm_exec_core
     2.38%  ruby             libruby.so.3.0.2    [.] vm_call0_body
     2.13%  ruby             libruby.so.3.0.2    [.] rb_funcallv
     1.52%  ruby             libruby.so.3.0.2    [.] ary_memcpy0
     1.49%  ruby             narray.so           [.] ndloop_release
     1.44%  ruby             libruby.so.3.0.2    [.] rb_gc_writebarrier
     1.36%  ruby             narray.so           [.] na_ndloop_main
     1.33%  ruby             libruby.so.3.0.2    [.] rb_yield_1
     1.30%  ruby             libruby.so.3.0.2    [.] rb_typeddata_inherited_p@plt
     1.19%  ruby             libruby.so.3.0.2    [.] ruby_yyparse
     1.17%  ruby             libruby.so.3.0.2    [.] rb_obj_class
     1.14%  ruby             narray.so           [.] na_release_lock
     1.10%  swapper          [kernel.kallsyms]   [k] 0xffffffff8f3fa754
     1.00%  ruby             narray.so           [.] loop_narray
     0.99%  ruby             libruby.so.3.0.2    [.] vm_call_cfunc_with_frame
     0.95%  ruby             libruby.so.3.0.2    [.] rb_ensure
     0.92%  ruby             narray.so           [.] nary_get_pointer_for_read_write
     0.87%  ruby             narray.so           [.] iter_dfloat_add
     0.84%  ruby             libruby.so.3.0.2    [.] rb_class_real
     0.81%  ruby             libruby.so.3.0.2    [.] ary_ensure_room_for_push
     0.81%  ruby             narray.so           [.] nary_get_pointer_for_read
     0.80%  ruby             libruby.so.3.0.2    [.] rb_wb_protected_newobj_of
     0.74%  ruby             narray.so           [.] na_ndloop
     0.73%  ruby             narray.so           [.] dfloat_add
     0.72%  ruby             libruby.so.3.0.2    [.] vm_yield_setup_args
     0.71%  ruby             libruby.so.3.0.2    [.] rb_ary_push
     0.71%  ruby             libruby.so.3.0.2    [.] rb_ary_tmp_new_from_values
     0.70%  ruby             libruby.so.3.0.2    [.] ruby_sized_xfree
     0.68%  ruby             narray.so           [.] nary_test_reduce
     0.65%  ruby             libruby.so.3.0.2    [.] rb_vm_exec
     0.65%  ruby             libruby.so.3.0.2    [.] rb_obj_alloc
     0.63%  ruby             libc-2.31.so        [.] malloc

[mrkn]

I investigated with non-optimized ruby to show the full call stack. The result is:

# To display the perf.data header info, please use --header/--header-only options.
#
#
# Total Lost Samples: 0
#
# Samples: 6K of event 'cycles'
# Event count (approx.): 5610555644
#
# Children      Self  Command          Shared Object             Symbol
# ........  ........  ...............  ........................  ....................................................................
#
    66.33%     0.00%  ruby             [unknown]                 [.] 0x000055756b40b6f0
            |
            ---0x55756b40b6f0
               |
               |--60.11%--vm_call_cfunc_with_frame
               |          |
               |           --58.78%--dfloat_add
               |                     |
               |                      --58.54%--dfloat_add_self
               |                                |
               |                                 --57.81%--na_ndloop
               |                                           |
               |                                           |--41.13%--rb_ensure
               |                                           |          |
               |                                           |          |--33.67%--ndloop_run
               |                                           |          |          |
               |                                           |          |          |--12.31%--ndloop_set_output
               |                                           |          |          |          |
               |                                           |          |          |           --10.42%--ndloop_set_output_narray
               |                                           |          |          |                     |
               |                                           |          |          |                     |--5.20%--ndloop_set_stepidx
               |                                           |          |          |                     |          |
               |                                           |          |          |                     |           --4.58%--nary_get_pointer_for_read_write
               |                                           |          |          |                     |                     |
               |                                           |          |          |                     |                      --3.45%--na_get_pointer_for_rw
               |                                           |          |          |                     |                                |
               |                                           |          |          |                     |                                 --2.22%--RB_OBJ_FROZEN
               |                                           |          |          |                     |                                           |
               |                                           |          |          |                     |                                            --0.92%--RB_TYPE_P
               |                                           |          |          |                     |                                                      |
               |                                           |          |          |                     |                                                       --0.82%--rb_type
               |                                           |          |          |                     |
               |                                           |          |          |                     |--1.78%--ndloop_find_inplace
               |                                           |          |          |                     |
               |                                           |          |          |                      --1.14%--rbimpl_size_mul_or_raise
               |                                           |          |          |
               |                                           |          |          |--7.89%--ndloop_init_args
               |                                           |          |          |          |
               |                                           |          |          |          |--1.91%--ndloop_set_stepidx
               |                                           |          |          |          |          |
               |                                           |          |          |          |           --1.13%--nary_get_pointer_for_read
               |                                           |          |          |          |
               |                                           |          |          |          |--0.78%--ndfunc_set_bufcp
               |                                           |          |          |          |
               |                                           |          |          |          |--0.66%--rb_type
               |                                           |          |          |          |
               |                                           |          |          |          |--0.65%--rbimpl_size_mul_or_raise
               |                                           |          |          |          |
               |                                           |          |          |          |--0.64%--iter_dfloat_add
               |                                           |          |          |          |
               |                                           |          |          |           --0.52%--ndfunc_set_user_loop
               |                                           |          |          |
               |                                           |          |          |--2.55%--loop_narray
               |                                           |          |          |          |
               |                                           |          |          |           --0.61%--iter_dfloat_add
               |                                           |          |          |
               |                                           |          |          |--0.93%--ndloop_cast_args
               |                                           |          |          |
               |                                           |          |           --0.59%--ndloop_alloc
               |                                           |          |
               |                                           |          |--2.45%--ndloop_release
               |                                           |          |          |
               |                                           |          |           --1.67%--na_release_lock
               |                                           |          |                     |
               |                                           |          |                     |--0.76%--na_release_lock
               |                                           |          |                     |          |
               |                                           |          |                     |           --0.64%--ndloop_alloc
               |                                           |          |                     |
               |                                           |          |                      --0.62%--ndloop_alloc
               |                                           |          |
               |                                           |           --1.82%--ndloop_alloc
               |                                           |
               |                                           |--13.89%--na_ndloop_main
               |                                           |          |
               |                                           |          |--4.67%--ndloop_alloc
               |                                           |          |          |
               |                                           |          |           --2.46%--ndloop_find_max_dimension
               |                                           |          |                     |
               |                                           |          |                      --0.72%--rb_array_len
               |                                           |          |
               |                                           |          |--2.11%--ndloop_cast_args
               |                                           |          |          |
               |                                           |          |           --0.85%--rb_type
               |                                           |          |
               |                                           |          |--0.93%--ndloop_set_output_narray
               |                                           |          |
               |                                           |          |--0.60%--ndloop_set_stepidx
               |                                           |          |
               |                                           |           --0.55%--ndloop_find_inplace
               |                                           |
               |                                            --0.93%--rbimpl_size_mul_or_raise
               |
                --0.95%--ndloop_alloc

[mrkn]

From the result with non-optimized ruby, rb_check_typeddata doesn't seem to be the main bottleneck.