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
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
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
