diff options
author | ko1 <ko1@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2012-06-15 10:22:34 +0000 |
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committer | ko1 <ko1@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2012-06-15 10:22:34 +0000 |
commit | 745c23b2d981e23024f044e934967bc6dae66d80 (patch) | |
tree | 9fd909ad9129bf5b11bbe1cbf77a11b6d9fc37b8 /vm_exec.c | |
parent | 0dc5b8ce8c11d196ed44d333c4bfae8c7f2d0bac (diff) |
* 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
Diffstat (limited to 'vm_exec.c')
-rw-r--r-- | vm_exec.c | 15 |
1 files changed, 1 insertions, 14 deletions
@@ -25,14 +25,6 @@ #endif /* #define DECL_SC_REG(r, reg) VALUE reg_##r */ -#if OPT_STACK_CACHING -static VALUE finish_insn_seq[1] = { BIN(finish_SC_ax_ax) }; -#elif OPT_CALL_THREADED_CODE -static VALUE const finish_insn_seq[1] = { 0 }; -#else -static VALUE finish_insn_seq[1] = { BIN(finish) }; -#endif - #if !OPT_CALL_THREADED_CODE static VALUE vm_exec_core(rb_thread_t *th, VALUE initial) @@ -84,11 +76,6 @@ vm_exec_core(rb_thread_t *th, VALUE initial) #if OPT_TOKEN_THREADED_CODE || OPT_DIRECT_THREADED_CODE #include "vmtc.inc" if (UNLIKELY(th == 0)) { -#if OPT_STACK_CACHING - finish_insn_seq[0] = (VALUE)&&LABEL (finish_SC_ax_ax); -#else - finish_insn_seq[0] = (VALUE)&&LABEL (finish); -#endif return (VALUE)insns_address_table; } #endif @@ -145,7 +132,7 @@ vm_exec_core(rb_thread_t *th, VALUE initial) } } - if (VM_FRAME_TYPE(th->cfp) != VM_FRAME_MAGIC_FINISH) { + if (VM_FRAME_TYPE_FINISH_P(th->cfp)) { rb_bug("cfp consistency error"); } |