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author | Alan Wu <XrXr@users.noreply.github.com> | 2023-07-17 13:57:58 -0400 |
---|---|---|
committer | GitHub <noreply@github.com> | 2023-07-17 13:57:58 -0400 |
commit | f302e725e10ae05e613e2c24cae0741f65f2db91 (patch) | |
tree | f539d3b5a27636dde99dfe96ab07e917b4f62740 /vm_dump.c | |
parent | 105bdba899fbb10aa51115c4cd074ea42eb9e3e6 (diff) |
Remove __bp__ and speed-up bmethod calls (#8060)
Remove rb_control_frame_t::__bp__ and optimize bmethod calls
This commit removes the __bp__ field from rb_control_frame_t. It was
introduced to help MJIT, but since MJIT was replaced by RJIT, we can use
vm_base_ptr() to compute it from the SP of the previous control frame
instead. Removing the field avoids needing to set it up when pushing new
frames.
Simply removing __bp__ would cause crashes since RJIT and YJIT used a
slightly different stack layout for bmethod calls than the interpreter.
At the moment of the call, the two layouts looked as follows:
┌────────────┐ ┌────────────┐
│ frame_base │ │ frame_base │
├────────────┤ ├────────────┤
│ ... │ │ ... │
├────────────┤ ├────────────┤
│ args │ │ args │
├────────────┤ └────────────┘<─prev_frame_sp
│ receiver │
prev_frame_sp─>└────────────┘
RJIT & YJIT interpreter
Essentially, vm_base_ptr() needs to compute the address to frame_base
given prev_frame_sp in the diagrams. The presence of the receiver
created an off-by-one situation.
Make the interpreter use the layout the JITs use for iseq-to-iseq
bmethod calls. Doing so removes unnecessary argument shifting and
vm_exec_core() re-entry from the interpreter, yielding a speed
improvement visible through `benchmark/vm_defined_method.yml`:
patched: 7578743.1 i/s
master: 4796596.3 i/s - 1.58x slower
C-to-iseq bmethod calls now store one more VALUE than before, but that
should have negligible impact on overall performance.
Note that re-entering vm_exec_core() used to be necessary for firing
TracePoint events, but that's no longer the case since
9121e57a5f50bc91bae48b3b91edb283bf96cb6b.
Closes ruby/ruby#6428
Diffstat (limited to 'vm_dump.c')
-rw-r--r-- | vm_dump.c | 4 |
1 files changed, 2 insertions, 2 deletions
@@ -281,14 +281,14 @@ rb_vmdebug_stack_dump_th(VALUE thval) #if VMDEBUG > 2 -/* copy from vm.c */ +/* copy from vm_insnhelper.c */ static const VALUE * vm_base_ptr(const rb_control_frame_t *cfp) { const rb_control_frame_t *prev_cfp = RUBY_VM_PREVIOUS_CONTROL_FRAME(cfp); const VALUE *bp = prev_cfp->sp + ISEQ_BODY(cfp->iseq)->local_table_size + VM_ENV_DATA_SIZE; - if (ISEQ_BODY(cfp->iseq)->type == ISEQ_TYPE_METHOD) { + if (ISEQ_BODY(cfp->iseq)->type == ISEQ_TYPE_METHOD || VM_FRAME_BMETHOD_P(cfp)) { bp += 1; } return bp; |