diff options
| author | Daniel Colson <danieljamescolson@gmail.com> | 2022-11-22 21:16:11 -0500 |
|---|---|---|
| committer | John Hawthorn <john@hawthorn.email> | 2022-12-06 12:37:23 -0800 |
| commit | e69b91fae4602b69c5ef45fcf82932adde8b31d8 (patch) | |
| tree | 7b3466a4199eadf6bb00773145895697b1455748 /yjit | |
| parent | c43951e60eed0b01f464cd25441b81751d2d5087 (diff) | |
Introduce BOP_CMP for optimized comparison
Prior to this commit the `OPTIMIZED_CMP` macro relied on a method lookup
to determine whether `<=>` was overridden. The result of the lookup was
cached, but only for the duration of the specific method that
initialized the cmp_opt_data cache structure.
With this method lookup, `[x,y].max` is slower than doing `x > y ?
x : y` even though there's an optimized instruction for "new array max".
(John noticed somebody a proposed micro-optimization based on this fact
in https://github.com/mastodon/mastodon/pull/19903.)
```rb
a, b = 1, 2
Benchmark.ips do |bm|
bm.report('conditional') { a > b ? a : b }
bm.report('method') { [a, b].max }
bm.compare!
end
```
Before:
```
Comparison:
conditional: 22603733.2 i/s
method: 19820412.7 i/s - 1.14x (± 0.00) slower
```
This commit replaces the method lookup with a new CMP basic op, which
gives the examples above equivalent performance.
After:
```
Comparison:
method: 24022466.5 i/s
conditional: 23851094.2 i/s - same-ish: difference falls within
error
```
Relevant benchmarks show an improvement to Array#max and Array#min when
not using the optimized newarray_max instruction as well. They are
noticeably faster for small arrays with the relevant types, and the same
or maybe a touch faster on larger arrays.
```
$ make benchmark COMPARE_RUBY=<master@5958c305> ITEM=array_min
$ make benchmark COMPARE_RUBY=<master@5958c305> ITEM=array_max
```
The benchmarks added in this commit also look generally improved.
Co-authored-by: John Hawthorn <jhawthorn@github.com>
Diffstat (limited to 'yjit')
| -rw-r--r-- | yjit/src/cruby_bindings.inc.rs | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/yjit/src/cruby_bindings.inc.rs b/yjit/src/cruby_bindings.inc.rs index 0afa82607c..470b6d0a5b 100644 --- a/yjit/src/cruby_bindings.inc.rs +++ b/yjit/src/cruby_bindings.inc.rs @@ -720,7 +720,8 @@ pub const BOP_MIN: ruby_basic_operators = 25; pub const BOP_CALL: ruby_basic_operators = 26; pub const BOP_AND: ruby_basic_operators = 27; pub const BOP_OR: ruby_basic_operators = 28; -pub const BOP_LAST_: ruby_basic_operators = 29; +pub const BOP_CMP: ruby_basic_operators = 29; +pub const BOP_LAST_: ruby_basic_operators = 30; pub type ruby_basic_operators = u32; pub type rb_serial_t = ::std::os::raw::c_ulonglong; extern "C" { |