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author | Alan Wu <XrXr@users.noreply.github.com> | 2023-07-17 13:57:58 -0400 |
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committer | GitHub <noreply@github.com> | 2023-07-17 13:57:58 -0400 |
commit | f302e725e10ae05e613e2c24cae0741f65f2db91 (patch) | |
tree | f539d3b5a27636dde99dfe96ab07e917b4f62740 /rjit_c.rb | |
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 'rjit_c.rb')
-rw-r--r-- | rjit_c.rb | 1 |
1 files changed, 0 insertions, 1 deletions
@@ -1064,7 +1064,6 @@ module RubyVM::RJIT # :nodoc: all self: [self.VALUE, Primitive.cexpr!("OFFSETOF((*((struct rb_control_frame_struct *)NULL)), self)")], ep: [CType::Pointer.new { self.VALUE }, Primitive.cexpr!("OFFSETOF((*((struct rb_control_frame_struct *)NULL)), ep)")], block_code: [CType::Immediate.parse("void *"), Primitive.cexpr!("OFFSETOF((*((struct rb_control_frame_struct *)NULL)), block_code)")], - __bp__: [CType::Pointer.new { self.VALUE }, Primitive.cexpr!("OFFSETOF((*((struct rb_control_frame_struct *)NULL)), __bp__)")], jit_return: [CType::Pointer.new { CType::Immediate.parse("void") }, Primitive.cexpr!("OFFSETOF((*((struct rb_control_frame_struct *)NULL)), jit_return)")], ) end |