diff options
Diffstat (limited to 'erts')
| -rw-r--r-- | erts/emulator/internal_doc/CountingInstructions.md | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/erts/emulator/internal_doc/CountingInstructions.md b/erts/emulator/internal_doc/CountingInstructions.md new file mode 100644 index 0000000000..d4b1213d00 --- /dev/null +++ b/erts/emulator/internal_doc/CountingInstructions.md @@ -0,0 +1,53 @@ +Counting Instructions +===================== + +Here is an example that shows how to count how many times each +instruction is executed: + + $ (cd erts/emulator && make icount) + MAKE icount + make[1]: Entering directory `/home/uabbgus/otp/erts/emulator' + . + . + . + make[1]: Leaving directory `/home/uabbgus/otp/erts/emulator' + $ cat t.erl + -module(t). + -compile([export_all,nowarn_export_all]). + + count() -> + erts_debug:ic(fun benchmark/0). + + benchmark() -> + %% Run dialyzer. + Root = code:root_dir(), + Wc1 = filename:join(Root, "lib/{kernel,stdlib}/ebin/*.beam"), + Wc2 = filename:join(Root, "erts/preloaded/ebin/*.beam"), + Files = filelib:wildcard(Wc1) ++ filelib:wildcard(Wc2), + Opts = [{analysis_type,plt_build},{files,Files},{get_warnings,true}], + dialyzer:run(Opts). + $ $ERL_TOP/bin/cerl -icount + Erlang/OTP 22 [RELEASE CANDIDATE 1] [erts-10.2.4] [source-ac0d451] [64-bit] [smp:4:4] [ds:4:4:10] [async-threads:1] [hipe] [instruction-counting] + + Eshell V10.2.4 (abort with ^G) + 1> c(t). + {ok,t} + 2> t:count(). + 0 badarg_j + 0 badmatch_x + 0 bs_add_jsstx + 0 bs_context_to_binary_x + . + . + . + 536461394 move_call_last_yfQ + 552405176 allocate_tt + 619920327 i_is_eq_exact_immed_frc + 636419163 is_nonempty_list_allocate_frtt + 641859278 i_get_tuple_element_xPx + 678196718 move_return_c + 786289914 is_tagged_tuple_frAa + 865826424 i_call_f + Total: 20728870321 + [] + 3> |