Feature #14814: rb_vm_insn_addr2insn: use sto to perform addr2insn mapping

• Status: Closed
• Assignee: -
• Target version: -

[normalperson (Eric Wong)]

The current VM_INSTRUCTION_SIZE is 198, so the linear search
becomes a bit painful.

I noticed rb_vm_insn_addr2insn2 showing up at the top of some
profiles while working on some malloc-related stuff, so I
decided to attack it.

With rubygems loaded running the benchmark suite (no --disable=gems),
this provides a significant speedup ratio for vm3_gc:

vm3_gc 1.446

Full results (with rubygems loaded):

https://80x24.org/spew/20180602220554.GA9991@whir/raw

Seems fairly straightforward, will commit in a few days.

[normalperson (Eric Wong)]

• Status changed from Open to Closed

Applied in changeset trunk|r63594.

---

rb_vm_insn_addr2insn: use st to perform addr2insn mapping

The current VM_INSTRUCTION_SIZE is 198, so the linear search
painful during a major GC phase.

I noticed rb_vm_insn_addr2insn2 showing up at the top of some
profiles while working on some malloc-related stuff, so I
decided to attack it.

Most notably, the benchmark/bm_vm3_gc.rb improves by over 40%:

https://80x24.org/spew/20180602220554.GA9991@whir/raw

[ruby-core:87361] [Feature #14814]