Commit graph

47 commits

Author SHA1 Message Date
Aaron Patterson
50c2c4bdde Make rb_vm_insns_count a thread local variable
`rb_vm_insns_count` is a global variable used for reporting YJIT
statistics. It is a counter that tallies the number of interpreter
instructions that have been executed, this way we can approximate how
much time we're spending in YJIT compared to the interpreter.

Unfortunately keeping this statistic means that every instruction
executed in the interpreter loop must increment the counter. Normally
this isn't a problem, but in multi-threaded situations (when Ractors are
used), incrementing this counter can become quite costly due to page
caching issues.

Additionally, since there is no locking when incrementing this global,
the count can't really make sense in a multi-threaded environment.

This commit changes `rb_vm_insns_count` to a thread local. That way each
Ractor has it's own copy of the counter and incrementing the counter
becomes quite cheap. Of course this means that in multi-threaded
situations, the value doesn't really make sense (but it didn't make
sense before because of the lack of locking).

The counter is used for YJIT statistics, and since YJIT is basically
disabled when Ractors are in use, I don't think we care about
inaccuracies (for the time being). We can revisit this counter when we
give YJIT multi-threading support, but for the time being this commit
restores multi-threaded performance.

To test this, I used the benchmark in [Bug #20489].

Here is the performance on Ruby 3.2:

```
$ time RUBY_MAX_CPU=12 ./miniruby -v ../test.rb 8 8
ruby 3.2.0 (2022-12-25 revision a528908271) [x86_64-linux]
[0...1, 1...2, 2...3, 3...4, 4...5, 5...6, 6...7, 7...8]
../test.rb:43: warning: Ractor is experimental, and the behavior may change in future versions of Ruby! Also there are many implementation issues.

________________________________________________________
Executed in    2.53 secs    fish           external
   usr time   19.86 secs  370.00 micros   19.86 secs
   sys time    0.02 secs  320.00 micros    0.02 secs
```

We can see the regression in performance on the master branch:

```
$ time RUBY_MAX_CPU=12 ./miniruby -v ../test.rb 8 8
ruby 3.5.0dev (2025-01-10T16:22:26Z master 4a2702dafb) +PRISM [x86_64-linux]
[0...1, 1...2, 2...3, 3...4, 4...5, 5...6, 6...7, 7...8]
../test.rb:43: warning: Ractor is experimental, and the behavior may change in future versions of Ruby! Also there are many implementation issues.

________________________________________________________
Executed in   24.87 secs    fish           external
   usr time  195.55 secs    0.00 micros  195.55 secs
   sys time    0.00 secs  716.00 micros    0.00 secs
```

Here are the stats after this commit:

```
$ time RUBY_MAX_CPU=12 ./miniruby -v ../test.rb 8 8
ruby 3.5.0dev (2025-01-10T20:37:06Z tl 3ef0432779) +PRISM [x86_64-linux]
[0...1, 1...2, 2...3, 3...4, 4...5, 5...6, 6...7, 7...8]
../test.rb:43: warning: Ractor is experimental, and the behavior may change in future versions of Ruby! Also there are many implementation issues.

________________________________________________________
Executed in    2.46 secs    fish           external
   usr time   19.34 secs  381.00 micros   19.34 secs
   sys time    0.01 secs  321.00 micros    0.01 secs
```

[Bug #20489]
2025-01-10 13:39:21 -08:00
Takashi Kokubun
96e4f42b3d RJIT: Correct the macro that defines rb_vm_insns_count 2023-12-19 00:06:21 -08:00
Takashi Kokubun
8c7cf2de98 Remove an unused argument in vm_exec_core 2023-07-27 17:31:27 -07:00
Takashi Kokubun
38be9a9b72
Clean up OPT_STACK_CACHING (#8132) 2023-07-27 17:27:05 -07:00
Takashi Kokubun
d814722fb8
YJIT: Make ratio_in_yjit always available (#8064) 2023-07-13 18:14:43 -04:00
Takashi Kokubun
b588fd5523 Remove an unused #if 0 code 2023-07-12 16:38:18 -07:00
Takashi Kokubun
d45118aaaf Remove obsoleted USE_INSNS_COUNTER macro for now
I don't use that these days. I'd like to remove this to ease a change
I'm writing. I'll resurrect this when I need this again.
2023-07-11 14:36:36 -07:00
S-H-GAMELINKS
1f4f6c9832 Using UNDEF_P macro 2022-11-16 18:58:33 +09:00
Sergey Fedorov
567725ed30
Fix and improve coroutines for Darwin (macOS) ppc/ppc64. (#5975) 2022-10-19 23:49:45 +13:00
Takashi Kokubun
5b21e94beb Expand tabs [ci skip]
[Misc #18891]
2022-07-21 09:42:04 -07:00
Alan Wu
7c08538aa3 Cleanup diff against upstream. Add comments
I did a `git diff --stat` against upstream and looked at all the files
that are outside of YJIT to come up with these minor changes.
2021-10-20 18:19:42 -04:00
Alan Wu
410323bd6d Try to convince get better code out of Clang 2021-10-20 18:19:22 -04:00
Nobuyoshi Nakada
f584dc5a11 Suppress unused-function warning when OPT_THREADED_CODE != 1 2021-08-09 11:21:56 +09:00
Benoit Daloze
68d6bd0873 Fix trivial -Wundef warnings
* See [Feature #17752]

Co-authored-by: xtkoba (Tee KOBAYASHI) <xtkoba+ruby@gmail.com>
2021-05-04 14:56:55 +02:00
AGSaidi
511b55bcef
Enable arm64 optimizations that exist for power/x86 (#3393)
* Enable unaligned accesses on arm64

64-bit Arm platforms support unaligned accesses.

Running the string benchmarks this change improves performance
by an average of 1.04x, min .96x, max 1.21x, median 1.01x

* arm64 enable gc optimizations

Similar to x86 and powerpc optimizations.

|       |compare-ruby|built-ruby|
|:------|-----------:|---------:|
|hash1  |       0.225|     0.237|
|       |           -|     1.05x|
|hash2  |       0.110|     0.110|
|       |       1.00x|         -|

* vm_exec.c: improve performance for arm64

|                               |compare-ruby|built-ruby|
|:------------------------------|-----------:|---------:|
|vm_array                       |     26.501M|   27.959M|
|                               |           -|     1.06x|
|vm_attr_ivar                   |     21.606M|   31.429M|
|                               |           -|     1.45x|
|vm_attr_ivar_set               |     21.178M|   26.113M|
|                               |           -|     1.23x|
|vm_backtrace                   |       6.621|     6.668|
|                               |           -|     1.01x|
|vm_bigarray                    |     26.205M|   29.958M|
|                               |           -|     1.14x|
|vm_bighash                     |    504.155k|  479.306k|
|                               |       1.05x|         -|
|vm_block                       |     16.692M|   21.315M|
|                               |           -|     1.28x|
|block_handler_type_iseq        |       5.083|     7.004|
|                               |           -|     1.38x|
2020-08-14 02:15:54 +09:00
卜部昌平
215c6fa3d0 RUBY_CONST_ASSERT: use STATIC_ASSERT instead
Static assertions shall be done using STATIC_ASSERT these days.
2020-07-10 12:23:41 +09:00
Takashi Kokubun
a994b0aee7
Add VM insns counter like debug_counter (#2789) 2019-12-28 00:44:09 -08:00
nobu
c9173b6a5c vm_exec.c: reduced repeated same calls
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@62648 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2018-03-04 01:52:19 +00:00
ko1
7e9aca4071 catch up recent changes for call threaded code VM.
Fix compile errors for OPT_CALL_THREADED_CODE (in vm_opts.h).


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@60493 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2017-10-27 19:16:51 +00:00
ko1
04dc3a0ca6 vm_exec_core() accepts ec instead of th.
* vm_exec.c (vm_exec_core): accepts `ec` instead of `th`.

* vm_args.c (vm_caller_setup_arg_block): also accepts `ec`.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@60477 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2017-10-27 06:21:50 +00:00
ko1
837fd5e494 Use rb_execution_context_t instead of rb_thread_t
to represent execution context [Feature #14038]

* vm_core.h (rb_thread_t): rb_thread_t::ec is now a pointer.
  There are many code using `th` to represent execution context
  (such as cfp, VM stack and so on). To access `ec`, they need to
  use `th->ec->...` (adding one indirection) so that we need to
  replace them by passing `ec` instead of `th`.

* vm_core.h (GET_EC()): introduced to access current ec. Also
  remove `ruby_current_thread` global variable.

* cont.c (rb_context_t): introduce rb_context_t::thread_ptr instead of
  rb_context_t::thread_value.

* cont.c (ec_set_vm_stack): added to update vm_stack explicitly.

* cont.c (ec_switch): added to switch ec explicitly.

* cont.c (rb_fiber_close): added to terminate fibers explicitly.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@60440 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2017-10-26 08:32:49 +00:00
hsbt
0e2d2e6a79 Drop to support NaCl platform.
Because NaCl and PNaCl are already sunset status.
  see https://bugs.chromium.org/p/chromium/issues/detail?id=239656#c160

  configure.ac: Patch for this file was provided by @nobu.

  [Feature #14041][ruby-core:83497][fix GH-1726]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@60374 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2017-10-23 05:56:25 +00:00
ko1
8dd9c12c58 move fields to ec.
* vm_core.h (rb_thread.h): move errinfo and trace_arg to
  rb_execution_context_t.

* cont.c (fiber_switch, rb_cont_call): do not restore "trace_arg" here.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59199 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2017-06-28 14:27:49 +00:00
normal
9d09240d9e rb_execution_context_t: move stack, stack_size and cfp from rb_thread_t
The goal is to reduce rb_context_t and rb_fiber_t size
by removing the need to store the entire rb_thread_t in
there.

[ruby-core:81045] Work-in-progress: soon, we will move more fields here.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58614 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2017-05-09 05:06:41 +00:00
ko1
b0569e3dde * vm_insnhelper.h: rename REG_(CFP|PC|SP|EP) to VM_REG_....
[Bug #12527]

* vm_exec.c: ditto.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56609 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2016-11-05 16:31:25 +00:00
ko1
18f6978625 * vm_core.h: constify rb_iseq_constant_body::iseq_encoded and
rb_control_frame_t::pc.
* compile.c (rb_iseq_translate_threaded_code): catch up this fix.
* iseq.c: ditto.
* vm_exec.c (vm_exec_core): ditto.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@51356 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2015-07-23 09:34:31 +00:00
hsbt
d1075b72c8 * vm_exec.c: improve performance in ppc64 arch.
[ruby-core:63437] [Feature #9997]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47149 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2014-08-12 03:59:39 +00:00
yugui
ab4e0ab458 * vm_exec.c (cfp): Fixes a SEGV issue in r44554.
r11 can be broken by subroutine and sometimes causes SEGV at
  runtime.  Use r13 instead.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@44590 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2014-01-14 02:32:45 +00:00
yugui
e85e95c409 * vm_exec.c (cfp): Avoid generating invalid binary for
NativeClient.
  r15 on x86_64 is reserved by NativeClient.  So r15 to cfp used to
  generate invalid binary under some combinations of compiler
  optimization flags.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@44554 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2014-01-10 09:22:37 +00:00
ko1
26e553d0ed * vm_exec.h (VM_DEBUG_STACKOVERFLOW): added.
disable stack overflow check for every stack pushing as default.
* vm_exec.c (vm_stack_overflow_for_insn): ditto.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@44275 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2013-12-18 05:33:50 +00:00
nobu
52e35469f0 vm_core.h: extract VM_STACK_OVERFLOWED_P
* vm_core.h (VM_STACK_OVERFLOWED_P, WHEN_VM_STACK_OVERFLOWED): extract
  condition from CHECK_VM_STACK_OVERFLOW.

* vm_exec.c (vm_stack_overflow_for_insn): move rb_bug call.

* vm_exec.h (CHECK_VM_STACK_OVERFLOW_FOR_INSN): share the condition
  with CHECK_VM_STACK_OVERFLOW.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43702 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2013-11-18 02:29:58 +00:00
naruse
9b113a0d6b * vm_exec.c: Correct predefined macro name. This typo is introduced by
r36534 and should be backported to ruby_2_0_0.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39806 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2013-03-18 01:45:12 +00:00
ko1
9975712793 * vm_exec.c: check VM_COLLECT_USAGE_DETAILS.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@38164 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2012-12-03 11:38:43 +00:00
ko1
fcc557a8f4 * vm_exec.c: vm_analysis_insn should be statkc.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@38160 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2012-12-03 11:00:37 +00:00
tenderlove
4c740bae97 * probes.d: add DTrace probe declarations. [ruby-core:27448]
* array.c (empty_ary_alloc, ary_new): added array create DTrace probe.

* compile.c (rb_insns_name): allowing DTrace probes to access
  instruction sequence name.

* Makefile.in: translate probes.d file to appropriate header file.

* common.mk: declare dependencies on the DTrace header.

* configure.in: add a test for existence of DTrace.

* eval.c (setup_exception): add a probe for when an exception is
  raised.

* gc.c: Add DTrace probes for mark begin and end, and sweep begin and
  end.

* hash.c (empty_hash_alloc): Add a probe for hash allocation.

* insns.def: Add probes for function entry and return.

* internal.h: function declaration for compile.c change.

* load.c (rb_f_load): add probes for `load` entry and exit, require
  entry and exit, and wrapping search_required for load path search.

* object.c (rb_obj_alloc): added a probe for general object creation.

* parse.y (yycompile0): added a probe around parse and compile phase.

* string.c (empty_str_alloc, str_new): DTrace probes for string
  allocation.

* test/dtrace/*: tests for DTrace probes.

* vm.c (vm_invoke_proc): add probes for function return on exception
  raise, hash create, and instruction sequence execution.

* vm_core.h: add probe declarations for function entry and exit.

* vm_dump.c: add probes header file.

* vm_eval.c (vm_call0_cfunc, vm_call0_cfunc_with_frame): add probe on
  function entry and return.

* vm_exec.c: expose instruction number to instruction name function.

* vm_insnshelper.c: add function entry and exit probes for cfunc
  methods.

* vm_insnhelper.h: vm usage information is always collected, so
  uncomment the functions.

12 19:14:50 2012  Akinori MUSHA  <knu@iDaemons.org>

* configure.in (isinf, isnan): isinf() and isnan() are macros on
  DragonFly which cannot be found by AC_REPLACE_FUNCS().  This
  workaround enforces the fact that they exist on DragonFly.

12 15:59:38 2012  Shugo Maeda  <shugo@ruby-lang.org>

* vm_core.h (rb_call_info_t::refinements), compile.c (new_callinfo),
  vm_insnhelper.c (vm_search_method): revert r37616 because it's too
  slow.  [ruby-dev:46477]

* test/ruby/test_refinement.rb (test_inline_method_cache): skip
  the test until the bug is fixed efficiently.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@37631 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2012-11-12 21:52:12 +00:00
ko1
0d1a905edb * vm_exec.c, insns.def (leave): solve problems on
OPT_CALL_THREADED_CODE.
  Catch up finish frame structure on OPT_CALL_THREADED_CODE.
* vm_core.h: add rb_thread_t#retval for temporary space on
  OPT_CALL_THREADED_CODE.
* vm.c (th_init): clear rb_thread_t#retval as Qundef.
* vm_dump.c (rb_vmdebug_debug_print_pre): fix debug print format.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@36652 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2012-08-07 11:13:57 +00:00
naruse
131f694330 Suppress warnings.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@36534 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2012-07-25 06:49:35 +00:00
ko1
745c23b2d9 * vm_core.h: remove VM_FRAME_MAGIC_FINISH (finish frame type).
Before this commit:
  `finish frame' was place holder which indicates that VM loop
  needs to return function.
  If a C method calls a Ruby methods (a method written by Ruby),
  then VM loop will be (re-)invoked.  When the Ruby method returns,
  then also VM loop should be escaped.  `finish frame' has only
  one instruction `finish', which returns VM loop function.
  VM loop function executes `finish' instruction, then VM loop
  function returns itself.
  With such mechanism, `leave' instruction (which returns one
  frame from current scope) doesn't need to check that this `leave'
  should also return from VM loop function.
  Strictly, one branch can be removed from `leave' instructon.
  Consideration:
  However, pushing the `finish frame' needs costs because
  it needs several memory accesses.  The number of pushing
  `finish frame' is greater than I had assumed.  Of course,
  pushing `finish frame' consumes additional control frame.
  Moreover, recent processors has good branch prediction,
  with which we can ignore such trivial checking.
  After this commit:
  Finally, I decide to remove `finish frame' and `finish'
  instruction.  Some parts of VM depend on `finish frame',
  so the new frame flag VM_FRAME_FLAG_FINISH is introduced.
  If this frame should escape from VM function loop, then
  the result of VM_FRAME_TYPE_FINISH_P(cfp) is true.
  `leave' instruction checks this flag every time.
  I measured performance on it.  However on my environments,
  it improves some benchmarks and slows some benchmarks down.
  Maybe it is because of C compiler optimization parameters.
  I'll re-visit here if this cause problems.
* insns.def (leave, finish): remove finish instruction.
* vm.c, vm_eval.c, vm_exec.c, vm_backtrace.c, vm_dump.c:
  apply above changes.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@36099 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2012-06-15 10:22:34 +00:00
naruse
70c97ec805 * vm_exec.c: remove conditions for clang
because clang version 3.0 (trunk 132165) doesn't need them.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@31846 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2011-05-31 02:08:58 +00:00
naruse
60aa9c809b * include/ruby/intern.h: pcc can't use __builtin_constant_p.
* vm_exec.c: change condition.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@31327 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2011-04-23 17:34:58 +00:00
naruse
fba68f4c31 * vm_exec.c (vm_exec_core): Treat clang as non gcc on this
context: It has __asm__ but doesn't works well.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@29419 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2010-10-07 00:48:03 +00:00
naruse
404ed4f8d4 * vm_exec.c (DECL_SC_REG): use __clang__.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@25504 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2009-10-27 00:29:06 +00:00
naruse
2215293a66 * vm_exec.c (DECL_SC_REG): check defined(__asm__) before use it.
LLVM/clang defines __GNUC__ but doesn't have __asm__..

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@25493 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2009-10-26 20:14:16 +00:00
ko1
cf23d0f0f0 * vm.c: add a prefix "rb_" to exposed functions
vm_get_ruby_level_next_cfp(), rb_vm_make_env_object(),
  vm_stack_to_heap(), vm_make_proc(), vm_invoke_proc(),
  vm_get_sourceline(), vm_cref(), vm_localjump_error(),
  vm_make_jump_tag_but_local_jump(), vm_jump_tag_but_local_jump().
  This changes may affect only core because most of renamed functions
  require a pointer of not-exposed struct such as rb_thread_t or NODE.
  In short, they are core functions.
* cont.c, eval.c, eval_intern.h, load.c, proc.c, thread.c,
  vm_core.h, vm_dump.c, vm_eval.c, vm_exec.c, vm_insnhelper.c:
  ditto.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@21659 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2009-01-19 02:38:11 +00:00
mame
e1a2fec2bb * README.EXT, README.EXT.ja, vm_exec.c, vm_insnhelper.c: update
filenames.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@20233 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2008-11-14 11:31:10 +00:00
ko1
574027ba03 * vm_exec.c (vm_exec_core): add an UNLIKELY() hint.
* vm_insnhelper.h (BASIC_OP_UNREDEFINED_P): add a LIKELY() hint.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@19605 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2008-09-28 07:13:06 +00:00
ko1
8cd252ac6f * common.mk: clean up
- remove blockinlining.$(OBJEXT) to built
  - make ENCODING_H_INCLDUES variable (include/ruby/encoding.h)
  - make VM_CORE_H_INCLUDES variable (vm_core.h)
  - simplify rules.
  - make depends rule to output depend status using gcc -MM.
* include/ruby/mvm.h, include/ruby/vm.h: rename mvm.h to vm.h.
* include/ruby.h: ditto.
* load.c: add inclusion explicitly.
* enumerator.c, object.c, parse.y, thread.c, vm_dump.c:
  remove useless inclusion.
* eval_intern.h: cleanup inclusion.
* vm_core.h: rb_thread_t should be defined in this file.
* vm_evalbody.c, vm_exec.c: rename vm_evalbody.c to vm_exec.c.
* vm.h, vm_exec.h: rename vm.h to vm_exec.h.
* insnhelper.h, vm_insnhelper.h: rename insnhelper.h to vm_insnhelper.h.
* vm.c, vm_insnhelper.c, vm_insnhelper.h:
  - rename vm_eval() to vm_exec_core().
  - rename vm_eval_body() to vm_exec().
  - cleanup include order.
* vm_method.c: fix comment.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@19466 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2008-09-23 00:20:28 +00:00
Renamed from vm_evalbody.c (Browse further)