diff options
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_core.h | |
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_core.h')
-rw-r--r-- | vm_core.h | 1 |
1 files changed, 0 insertions, 1 deletions
@@ -815,7 +815,6 @@ typedef struct rb_control_frame_struct { VALUE self; /* cfp[3] / block[0] */ const VALUE *ep; /* cfp[4] / block[1] */ const void *block_code; /* cfp[5] / block[2] */ /* iseq or ifunc or forwarded block handler */ - VALUE *__bp__; /* cfp[6] */ /* outside vm_push_frame, use vm_base_ptr instead. */ #if VM_DEBUG_BP_CHECK VALUE *bp_check; /* cfp[7] */ |