YJIT: Initial support for rest args

[jimmyhmiller]

Here are the stats of railsbench and liquid-render before and after these changes.

As you can see many of the iseq_has_rest turned into iseq_has_rest_and_splat. That's my plan to tackle next. I don't think it should be too hard, but just wanted to keep things incremental.

Rails Bench Before

         ***YJIT: Printing YJIT statistics on exit***
method call exit reasons: 
                      iseq_has_rest     108003 (32.3%)
                          block_arg      64648 (19.3%)
                        iseq_zsuper      46081 (13.8%)
                   iseq_arity_error      28708 ( 8.6%)
                iseq_ruby2_keywords      24995 ( 7.5%)
          args_splat_cfunc_var_args      16251 ( 4.9%)
                     iseq_has_no_kw      15971 ( 4.8%)
                           kw_splat      12995 ( 3.9%)
                    iseq_has_kwrest       5294 ( 1.6%)
           iseq_missing_optional_kw       4054 ( 1.2%)
        splatarray_length_not_equal       2029 ( 0.6%)
             args_splat_cfunc_zuper       2002 ( 0.6%)
                      iseq_has_post       1986 ( 0.6%)
                     refined_method        891 ( 0.3%)
              cfunc_ruby_array_varg        653 ( 0.2%)
                           keywords        102 ( 0.0%)
    args_splat_cfunc_ruby2_keywords         62 ( 0.0%)
                    args_splat_ivar         49 ( 0.0%)
                        send_getter         12 ( 0.0%)
                      zsuper_method          9 ( 0.0%)
                args_splat_opt_call          5 ( 0.0%)
                    ivar_set_method          2 ( 0.0%)
                  bmethod_block_arg          2 ( 0.0%)
invokeblock exit reasons: 
               ifunc       5798 (56.0%)
                proc       2385 (23.0%)
     iseq_arg0_splat       2000 (19.3%)
    iseq_tag_changed        106 ( 1.0%)
              symbol         68 ( 0.7%)
invokesuper exit reasons: 
         block       4850 (98.2%)
    me_changed         87 ( 1.8%)
leave exit reasons: 
        interp_return    1852586 (97.7%)
    start_pc_non_zero      43886 ( 2.3%)
         se_interrupt         34 ( 0.0%)
getblockparamproxy exit reasons: 
    block_param_modified          3 (100.0%)
getinstancevariable exit reasons:
    megamorphic      13685 (100.0%)
setinstancevariable exit reasons:
    (all relevant counters are zero)
opt_aref exit reasons: 
    (all relevant counters are zero)
expandarray exit reasons: 
            splat       9973 (99.8%)
    rhs_too_small         22 ( 0.2%)
opt_getinlinecache exit reasons: 
    miss         11 (100.0%)
invalidation reasons: 
       constant_ic_fill       2015 (59.3%)
          method_lookup       1044 (30.7%)
    constant_state_bump        339 (10.0%)
bindings_allocations:         184
bindings_set:                   0
compiled_iseq_count:         9290
compiled_block_count:       51999
compiled_branch_count:      82406
block_next_count:           15210
defer_count:                16299
freed_iseq_count:            4060
invalidation_count:          3398
constant_state_bumps:           0
inline_code_size:         8825496
outlined_code_size:       8822420
freed_code_size:                0
code_region_size:        17694720
yjit_alloc_size:         98211797
live_page_count:             1080
freed_page_count:               0
code_gc_count:                  0
num_gc_obj_refs:            41295
object_shape_count:          2397
side_exit_count:           513493
total_exit_count:         2366079
total_insns_count:       89905782
vm_insns_count:           8771865
yjit_insns_count:        81647410
ratio_in_yjit:              90.2%
avg_len_in_yjit:             34.3
Top-20 most frequent exit ops (100.0% of exits):
    opt_send_without_block:     141965 (27.6%)
               invokesuper:     117078 (22.8%)
                      send:     104052 (20.3%)
      opt_getconstant_path:      57739 (11.2%)
               invokeblock:      37042 (7.2%)
                  opt_aref:      14088 (2.7%)
                     throw:      10587 (2.1%)
               expandarray:       9995 (1.9%)
             setlocal_WC_0:       8358 (1.6%)
                    opt_eq:       5010 (1.0%)
       getinstancevariable:       3485 (0.7%)
        getblockparamproxy:       2271 (0.4%)
               objtostring:        448 (0.1%)
          putspecialobject:        386 (0.1%)
                 opt_nil_p:        327 (0.1%)
             definesmethod:        240 (0.0%)
                checkmatch:        204 (0.0%)
                      once:        104 (0.0%)
                     leave:         35 (0.0%)
               opt_empty_p:         31 (0.0%)

Rails Bench After

         ***YJIT: Printing YJIT statistics on exit***
method call exit reasons: 
                          block_arg:     64,659 (18.3%)
            iseq_has_rest_and_splat:     52,145 (14.8%)
                        iseq_zsuper:     46,080 (13.0%)
            iseq_has_rest_and_block:     43,558 (12.3%)
                   iseq_arity_error:     30,708 ( 8.7%)
                  klass_megamorphic:     27,431 ( 7.8%)
                iseq_ruby2_keywords:     25,025 ( 7.1%)
                     iseq_has_no_kw:     17,292 ( 4.9%)
          args_splat_cfunc_var_args:     16,251 ( 4.6%)
                           kw_splat:     12,995 ( 3.7%)
                    iseq_has_kwrest:      7,320 ( 2.1%)
           iseq_missing_optional_kw:      4,054 ( 1.1%)
             args_splat_cfunc_zuper:      2,002 ( 0.6%)
                      iseq_has_post:      1,988 ( 0.6%)
                     refined_method:        891 ( 0.3%)
              cfunc_ruby_array_varg:        653 ( 0.2%)
               iseq_has_rest_and_kw:        172 ( 0.0%)
                           keywords:        102 ( 0.0%)
    args_splat_cfunc_ruby2_keywords:         62 ( 0.0%)
                    args_splat_ivar:         49 ( 0.0%)
         iseq_has_rest_and_optional:         14 ( 0.0%)
                        send_getter:         12 ( 0.0%)
                      zsuper_method:          9 ( 0.0%)
                args_splat_opt_call:          5 ( 0.0%)
                    ivar_set_method:          2 ( 0.0%)
        splatarray_length_not_equal:          2 ( 0.0%)
                  bmethod_block_arg:          2 ( 0.0%)
invokeblock exit reasons: 
      proc:      2,385 (93.2%)
    symbol:        174 ( 6.8%)
invokesuper exit reasons: 
    me_changed:      4,783 (95.0%)
         block:        254 ( 5.0%)
leave exit reasons: 
        interp_return:  1,812,675 (97.6%)
    start_pc_non_zero:     43,882 ( 2.4%)
         se_interrupt:         34 ( 0.0%)
getblockparamproxy exit reasons: 
    block_param_modified:          3 (100.0%)
getinstancevariable exit reasons:
    megamorphic:     13,685 (100.0%)
setinstancevariable exit reasons:
    (all relevant counters are zero)
opt_aref exit reasons: 
    (all relevant counters are zero)
expandarray exit reasons: 
            splat:      9,974 (99.8%)
    rhs_too_small:         22 ( 0.2%)
opt_getinlinecache exit reasons: 
    miss:         11 (100.0%)
invalidation reasons: 
       constant_ic_fill:      2,021 (59.4%)
          method_lookup:      1,045 (30.7%)
    constant_state_bump:        338 ( 9.9%)
num_send:                 13,369,456
num_send_known_class:        439,682 ( 3.3%)
num_send_polymorphic:      1,528,493 (11.4%)
bindings_allocations:              0
bindings_set:                      0
compiled_iseq_count:           9,292
compiled_block_count:         52,233
compiled_branch_count:        82,926
block_next_count:             15,307
defer_count:                  16,372
freed_iseq_count:              4,059
invalidation_count:            3,404
constant_state_bumps:              0
inline_code_size:          9,682,128
outlined_code_size:        9,680,184
freed_code_size:                   0
code_region_size:         19,365,888
live_page_count:               1,182
freed_page_count:                  0
code_gc_count:                     0
num_gc_obj_refs:              41,460
object_shape_count:            2,428
side_exit_count:             478,725
total_exit_count:          2,291,400
yjit_insns_count:         82,165,394
avg_len_in_yjit:                35.6
Top-20 most frequent exit ops (100.0% of exits):
    opt_send_without_block:    133,196 (27.8%)
               invokesuper:    104,824 (21.9%)
                      send:    100,073 (20.9%)
      opt_getconstant_path:     53,749 (11.2%)
               invokeblock:     31,243 ( 6.5%)
                  opt_aref:     14,085 ( 2.9%)
                     throw:     10,587 ( 2.2%)
               expandarray:      9,996 ( 2.1%)
             setlocal_WC_0:      8,380 ( 1.8%)
                    opt_eq:      5,009 ( 1.0%)
       getinstancevariable:      3,485 ( 0.7%)
        getblockparamproxy:      2,271 ( 0.5%)
               objtostring:        448 ( 0.1%)
          putspecialobject:        388 ( 0.1%)
                 opt_nil_p:        327 ( 0.1%)
             definesmethod:        240 ( 0.1%)
                checkmatch:        204 ( 0.0%)
                      once:        104 ( 0.0%)
                     leave:         35 ( 0.0%)
               opt_empty_p:         30 ( 0.0%)

Liquid Render Before

         ***YJIT: Printing YJIT statistics on exit***
method call exit reasons: 
                  iseq_has_rest      41416 (88.7%)
    splatarray_length_not_equal       2978 ( 6.4%)
                      block_arg       1461 ( 3.1%)
                  zsuper_method        792 ( 1.7%)
          cfunc_ruby_array_varg         34 ( 0.1%)
                    send_getter         12 ( 0.0%)
       iseq_missing_optional_kw          9 ( 0.0%)
      args_splat_cfunc_var_args          8 ( 0.0%)
                       kw_splat          3 ( 0.0%)
                ivar_set_method          1 ( 0.0%)
invokeblock exit reasons: 
                proc        334 (81.3%)
    iseq_tag_changed         77 (18.7%)
invokesuper exit reasons: 
    block         79 (100.0%)
leave exit reasons: 
        interp_return     297668 (100.0%)
    start_pc_non_zero        111 ( 0.0%)
         se_interrupt         11 ( 0.0%)
getblockparamproxy exit reasons: 
    (all relevant counters are zero)
getinstancevariable exit reasons:
    megamorphic         11 (100.0%)
setinstancevariable exit reasons:
    (all relevant counters are zero)
opt_aref exit reasons: 
    (all relevant counters are zero)
expandarray exit reasons: 
    rhs_too_small         10 (100.0%)
opt_getinlinecache exit reasons: 
    (all relevant counters are zero)
invalidation reasons: 
       constant_ic_fill        577 (81.3%)
    constant_state_bump         89 (12.5%)
          method_lookup         44 ( 6.2%)
bindings_allocations:         150
bindings_set:                   0
compiled_iseq_count:         1685
compiled_block_count:       11688
compiled_branch_count:      19097
block_next_count:            4081
defer_count:                 3831
freed_iseq_count:             556
invalidation_count:           710
constant_state_bumps:           0
inline_code_size:         1846724
outlined_code_size:       1843072
freed_code_size:                0
code_region_size:         3702784
yjit_alloc_size:         23174105
live_page_count:              226
freed_page_count:               0
code_gc_count:                  0
num_gc_obj_refs:             7821
object_shape_count:           770
side_exit_count:            67734
total_exit_count:          365402
total_insns_count:       20364975
vm_insns_count:           2483281
yjit_insns_count:        17949428
ratio_in_yjit:              87.8%
avg_len_in_yjit:             48.9
Top-18 most frequent exit ops (100.0% of exits):
    opt_send_without_block:      45508 (67.2%)
                     throw:      19099 (28.2%)
                      send:       1495 (2.2%)
      opt_getconstant_path:        748 (1.1%)
               invokeblock:        412 (0.6%)
               invokesuper:        203 (0.3%)
                    opt_eq:         88 (0.1%)
                      once:         87 (0.1%)
          putspecialobject:         37 (0.1%)
        getblockparamproxy:         11 (0.0%)
                     leave:         11 (0.0%)
                  opt_aref:         11 (0.0%)
               expandarray:         10 (0.0%)
             setlocal_WC_0:          7 (0.0%)
                  opt_ltlt:          3 (0.0%)
                checkmatch:          2 (0.0%)
                   opt_mod:          1 (0.0%)
               opt_empty_p:          1 (0.0%)

Liquid Render After

         ***YJIT: Printing YJIT statistics on exit***
method call exit reasons: 
      iseq_has_rest_and_splat:     40,610 (94.0%)
                    block_arg:      1,462 ( 3.4%)
                zsuper_method:        792 ( 1.8%)
            klass_megamorphic:        270 ( 0.6%)
        cfunc_ruby_array_varg:         34 ( 0.1%)
                  send_getter:         12 ( 0.0%)
         iseq_has_rest_and_kw:         10 ( 0.0%)
     iseq_missing_optional_kw:          9 ( 0.0%)
    args_splat_cfunc_var_args:          8 ( 0.0%)
                     kw_splat:          3 ( 0.0%)
              ivar_set_method:          1 ( 0.0%)
      iseq_has_rest_and_block:          1 ( 0.0%)
invokeblock exit reasons: 
      proc:        334 (81.3%)
    symbol:         77 (18.7%)
invokesuper exit reasons: 
    block:         79 (100.0%)
leave exit reasons: 
        interp_return:    297,480 (100.0%)
    start_pc_non_zero:        110 ( 0.0%)
         se_interrupt:         11 ( 0.0%)
getblockparamproxy exit reasons: 
    (all relevant counters are zero)
getinstancevariable exit reasons:
    megamorphic:          8 (100.0%)
setinstancevariable exit reasons:
    (all relevant counters are zero)
opt_aref exit reasons: 
    (all relevant counters are zero)
expandarray exit reasons: 
    rhs_too_small:         10 (100.0%)
opt_getinlinecache exit reasons: 
    (all relevant counters are zero)
invalidation reasons: 
       constant_ic_fill:        578 (81.0%)
    constant_state_bump:         92 (12.9%)
          method_lookup:         44 ( 6.2%)
num_send:                  3,026,363
num_send_known_class:        107,922 ( 3.6%)
num_send_polymorphic:        610,717 (20.2%)
bindings_allocations:              0
bindings_set:                      0
compiled_iseq_count:           1,685
compiled_block_count:         11,781
compiled_branch_count:        19,289
block_next_count:              4,122
defer_count:                   3,865
freed_iseq_count:                556
invalidation_count:              714
constant_state_bumps:              0
inline_code_size:          2,026,004
outlined_code_size:        2,025,124
freed_code_size:                   0
code_region_size:          4,063,232
live_page_count:                 248
freed_page_count:                  0
code_gc_count:                     0
num_gc_obj_refs:               7,856
object_shape_count:              771
side_exit_count:              63,831
total_exit_count:            361,311
yjit_insns_count:         17,948,548
avg_len_in_yjit:                49.5
Top-18 most frequent exit ops (100.0% of exits):
    opt_send_without_block:     41,728 (65.4%)
                     throw:     19,099 (29.9%)
                      send:      1,495 ( 2.3%)
      opt_getconstant_path:        749 ( 1.2%)
               invokeblock:        411 ( 0.6%)
                    opt_eq:         88 ( 0.1%)
                      once:         87 ( 0.1%)
               invokesuper:         80 ( 0.1%)
          putspecialobject:         37 ( 0.1%)
        getblockparamproxy:         11 ( 0.0%)
                     leave:         11 ( 0.0%)
               expandarray:         10 ( 0.0%)
                  opt_aref:         10 ( 0.0%)
             setlocal_WC_0:          7 ( 0.0%)
                  opt_ltlt:          4 ( 0.0%)
                checkmatch:          2 ( 0.0%)
                   opt_mod:          1 ( 0.0%)
       setinstancevariable:          1 ( 0.0%)

[YurySolovyov]

Rails bench after stats don't have ratio in yjit? 🤔

[k0kubun]

I noticed it too (It happens when you build Ruby without --enable-yjit=stats or --enable-yjit=dev), but I saw the numbers on "make yjit-bench" CI jobs anyway 🙂 (91.9% → 92.0%)

[maximecb]

Thank you Jimmy 👌