From the documentation of rb_obj_hash:
> Certain core classes such as Integer use built-in hash calculations and
> do not call the #hash method when used as a hash key.
So if you override, say, Integer#hash it won't be used from rb_hash_aref
and similar. This avoids method lookups in many common cases.
This commit uses the same optimization in rb_hash, a method used
internally and in the C API to get the hash value of an object. Usually
this is used to build the hash of an object based on its elements.
Previously it would always do a method lookup for 'hash'.
This is primarily intended to speed up hashing of Arrays and Hashes,
which call rb_hash for each element.
compare-ruby: ruby 3.0.1p64 (2021-04-05 revision 0fb782ee38) [x86_64-linux]
built-ruby: ruby 3.1.0dev (2021-09-29T02:13:24Z fast_hash d670bf88b2) [x86_64-linux]
# Iteration per second (i/s)
| |compare-ruby|built-ruby|
|:----------------|-----------:|---------:|
|hash_aref_array | 1.008| 1.769|
| | -| 1.76x|
In vm_call_method_each_type, check for c_call and c_return events before
dispatching to vm_call_ivar and vm_call_attrset. With this approach, the
call cache will still dispatch directly to those functions, so this
change will only decrease performance for the first (uncached) call, and
even then, the performance decrease is very minimal.
This approach requires that we clear the call caches when tracing is
enabled or disabled. The approach currently switches all vm_call_ivar
and vm_call_attrset call caches to vm_call_general any time tracing is
enabled or disabled. So it could theoretically result in a slowdown for
code that constantly enables or disables tracing.
This approach does not handle targeted tracepoints, but from my testing,
c_call and c_return events are not supported for targeted tracepoints,
so that shouldn't matter.
This includes a benchmark showing the performance decrease is minimal
if detectable at all.
Fixes [Bug #16383]
Fixes [Bug #10470]
Co-authored-by: Takashi Kokubun <takashikkbn@gmail.com>
Redo of 34a2acdac788602c14bf05fb616215187badd504 and
931138b00696419945dc03e10f033b1f53cd50f3 which were reverted.
GitHub PR #4340.
This change implements a cache for class variables. Previously there was
no cache for cvars. Cvar access is slow due to needing to travel all the
way up th ancestor tree before returning the cvar value. The deeper the
ancestor tree the slower cvar access will be.
The benefits of the cache are more visible with a higher number of
included modules due to the way Ruby looks up class variables. The
benchmark here includes 26 modules and shows with the cache, this branch
is 6.5x faster when accessing class variables.
```
compare-ruby: ruby 3.1.0dev (2021-03-15T06:22:34Z master 9e5105c) [x86_64-darwin19]
built-ruby: ruby 3.1.0dev (2021-03-15T12:12:44Z add-cache-for-clas.. c6be009) [x86_64-darwin19]
| |compare-ruby|built-ruby|
|:--------|-----------:|---------:|
|vm_cvar | 5.681M| 36.980M|
| | -| 6.51x|
```
Benchmark.ips calling `ActiveRecord::Base.logger` from within a Rails
application. ActiveRecord::Base.logger has 71 ancestors. The more
ancestors a tree has, the more clear the speed increase. IE if Base had
only one ancestor we'd see no improvement. This benchmark is run on a
vanilla Rails application.
Benchmark code:
```ruby
require "benchmark/ips"
require_relative "config/environment"
Benchmark.ips do |x|
x.report "logger" do
ActiveRecord::Base.logger
end
end
```
Ruby 3.0 master / Rails 6.1:
```
Warming up --------------------------------------
logger 155.251k i/100ms
Calculating -------------------------------------
```
Ruby 3.0 with cvar cache / Rails 6.1:
```
Warming up --------------------------------------
logger 1.546M i/100ms
Calculating -------------------------------------
logger 14.857M (± 4.8%) i/s - 74.198M in 5.006202s
```
Lastly we ran a benchmark to demonstate the difference between master
and our cache when the number of modules increases. This benchmark
measures 1 ancestor, 30 ancestors, and 100 ancestors.
Ruby 3.0 master:
```
Warming up --------------------------------------
1 module 1.231M i/100ms
30 modules 432.020k i/100ms
100 modules 145.399k i/100ms
Calculating -------------------------------------
1 module 12.210M (± 2.1%) i/s - 61.553M in 5.043400s
30 modules 4.354M (± 2.7%) i/s - 22.033M in 5.063839s
100 modules 1.434M (± 2.9%) i/s - 7.270M in 5.072531s
Comparison:
1 module: 12209958.3 i/s
30 modules: 4354217.8 i/s - 2.80x (± 0.00) slower
100 modules: 1434447.3 i/s - 8.51x (± 0.00) slower
```
Ruby 3.0 with cvar cache:
```
Warming up --------------------------------------
1 module 1.641M i/100ms
30 modules 1.655M i/100ms
100 modules 1.620M i/100ms
Calculating -------------------------------------
1 module 16.279M (± 3.8%) i/s - 82.038M in 5.046923s
30 modules 15.891M (± 3.9%) i/s - 79.459M in 5.007958s
100 modules 16.087M (± 3.6%) i/s - 81.005M in 5.041931s
Comparison:
1 module: 16279458.0 i/s
100 modules: 16087484.6 i/s - same-ish: difference falls within error
30 modules: 15891406.2 i/s - same-ish: difference falls within error
```
Co-authored-by: Aaron Patterson <tenderlove@ruby-lang.org>
* Improve perfomance for Integer#size method [Feature #17135]
* re-run ci
* Let MJIT frame skip work for Integer#size
Co-authored-by: Takashi Kokubun <takashikkbn@gmail.com>
The checkmatch instruction with VM_CHECKMATCH_TYPE_CASE calls
=== without a call cache. Emit a send instruction to make the call
instead. It includes a call cache.
The call cache improves throughput of using when statements to check the
class of a given object. This is useful for say, JSON serialization.
Use of a regular send instead of checkmatch also avoids taking the VM
lock every time, which is good for multi-ractor workloads.
Calculating -------------------------------------
master post
vm_case_classes 11.013M 16.172M i/s - 6.000M times in 0.544795s 0.371009s
vm_case_lit 2.296 2.263 i/s - 1.000 times in 0.435606s 0.441826s
vm_case 74.098M 64.338M i/s - 6.000M times in 0.080974s 0.093257s
Comparison:
vm_case_classes
post: 16172114.4 i/s
master: 11013316.9 i/s - 1.47x slower
vm_case_lit
master: 2.3 i/s
post: 2.3 i/s - 1.01x slower
vm_case
master: 74097858.6 i/s
post: 64338333.9 i/s - 1.15x slower
The vm_case benchmark is a bit slower post patch, possibily due to the
larger instruction sequence. The benchmark dispatches using
opt_case_dispatch so was not running checkmatch and does not make the
=== call post patch.
This change implements a cache for class variables. Previously there was
no cache for cvars. Cvar access is slow due to needing to travel all the
way up th ancestor tree before returning the cvar value. The deeper the
ancestor tree the slower cvar access will be.
The benefits of the cache are more visible with a higher number of
included modules due to the way Ruby looks up class variables. The
benchmark here includes 26 modules and shows with the cache, this branch
is 6.5x faster when accessing class variables.
```
compare-ruby: ruby 3.1.0dev (2021-03-15T06:22:34Z master 9e5105ca45) [x86_64-darwin19]
built-ruby: ruby 3.1.0dev (2021-03-15T12:12:44Z add-cache-for-clas.. c6be0093ae) [x86_64-darwin19]
| |compare-ruby|built-ruby|
|:--------|-----------:|---------:|
|vm_cvar | 5.681M| 36.980M|
| | -| 6.51x|
```
Benchmark.ips calling `ActiveRecord::Base.logger` from within a Rails
application. ActiveRecord::Base.logger has 71 ancestors. The more
ancestors a tree has, the more clear the speed increase. IE if Base had
only one ancestor we'd see no improvement. This benchmark is run on a
vanilla Rails application.
Benchmark code:
```ruby
require "benchmark/ips"
require_relative "config/environment"
Benchmark.ips do |x|
x.report "logger" do
ActiveRecord::Base.logger
end
end
```
Ruby 3.0 master / Rails 6.1:
```
Warming up --------------------------------------
logger 155.251k i/100ms
Calculating -------------------------------------
```
Ruby 3.0 with cvar cache / Rails 6.1:
```
Warming up --------------------------------------
logger 1.546M i/100ms
Calculating -------------------------------------
logger 14.857M (± 4.8%) i/s - 74.198M in 5.006202s
```
Lastly we ran a benchmark to demonstate the difference between master
and our cache when the number of modules increases. This benchmark
measures 1 ancestor, 30 ancestors, and 100 ancestors.
Ruby 3.0 master:
```
Warming up --------------------------------------
1 module 1.231M i/100ms
30 modules 432.020k i/100ms
100 modules 145.399k i/100ms
Calculating -------------------------------------
1 module 12.210M (± 2.1%) i/s - 61.553M in 5.043400s
30 modules 4.354M (± 2.7%) i/s - 22.033M in 5.063839s
100 modules 1.434M (± 2.9%) i/s - 7.270M in 5.072531s
Comparison:
1 module: 12209958.3 i/s
30 modules: 4354217.8 i/s - 2.80x (± 0.00) slower
100 modules: 1434447.3 i/s - 8.51x (± 0.00) slower
```
Ruby 3.0 with cvar cache:
```
Warming up --------------------------------------
1 module 1.641M i/100ms
30 modules 1.655M i/100ms
100 modules 1.620M i/100ms
Calculating -------------------------------------
1 module 16.279M (± 3.8%) i/s - 82.038M in 5.046923s
30 modules 15.891M (± 3.9%) i/s - 79.459M in 5.007958s
100 modules 16.087M (± 3.6%) i/s - 81.005M in 5.041931s
Comparison:
1 module: 16279458.0 i/s
100 modules: 16087484.6 i/s - same-ish: difference falls within error
30 modules: 15891406.2 i/s - same-ish: difference falls within error
```
Co-authored-by: Aaron Patterson <tenderlove@ruby-lang.org>
This allows us to allocate the right size for the object in advance,
meaning that we don't have to pay the cost of ivar table extension
later. The idea is that if an object type ever became "extended" at
some point, then it is very likely it will become extended again. So we
may as well allocate the ivar table up front.
In regular assignment, Ruby evaluates the left hand side before
the right hand side. For example:
```ruby
foo[0] = bar
```
Calls `foo`, then `bar`, then `[]=` on the result of `foo`.
Previously, multiple assignment didn't work this way. If you did:
```ruby
abc.def, foo[0] = bar, baz
```
Ruby would previously call `bar`, then `baz`, then `abc`, then
`def=` on the result of `abc`, then `foo`, then `[]=` on the
result of `foo`.
This change makes multiple assignment similar to single assignment,
changing the evaluation order of the above multiple assignment code
to calling `abc`, then `foo`, then `bar`, then `baz`, then `def=` on
the result of `abc`, then `[]=` on the result of `foo`.
Implementing this is challenging with the stack-based virtual machine.
We need to keep track of all of the left hand side attribute setter
receivers and setter arguments, and then keep track of the stack level
while handling the assignment processing, so we can issue the
appropriate topn instructions to get the receiver. Here's an example
of how the multiple assignment is executed, showing the stack and
instructions:
```
self # putself
abc # send
abc, self # putself
abc, foo # send
abc, foo, 0 # putobject 0
abc, foo, 0, [bar, baz] # evaluate RHS
abc, foo, 0, [bar, baz], baz, bar # expandarray
abc, foo, 0, [bar, baz], baz, bar, abc # topn 5
abc, foo, 0, [bar, baz], baz, abc, bar # swap
abc, foo, 0, [bar, baz], baz, def= # send
abc, foo, 0, [bar, baz], baz # pop
abc, foo, 0, [bar, baz], baz, foo # topn 3
abc, foo, 0, [bar, baz], baz, foo, 0 # topn 3
abc, foo, 0, [bar, baz], baz, foo, 0, baz # topn 2
abc, foo, 0, [bar, baz], baz, []= # send
abc, foo, 0, [bar, baz], baz # pop
abc, foo, 0, [bar, baz] # pop
[bar, baz], foo, 0, [bar, baz] # setn 3
[bar, baz], foo, 0 # pop
[bar, baz], foo # pop
[bar, baz] # pop
```
As multiple assignment must deal with splats, post args, and any level
of nesting, it gets quite a bit more complex than this in non-trivial
cases. To handle this, struct masgn_state is added to keep
track of the overall state of the mass assignment, which stores a linked
list of struct masgn_attrasgn, one for each assigned attribute.
This adds a new optimization that replaces a topn 1/pop instruction
combination with a single swap instruction for multiple assignment
to non-aref attributes.
This new approach isn't compatible with one of the optimizations
previously used, in the case where the multiple assignment return value
was not needed, there was no lhs splat, and one of the left hand side
used an attribute setter. This removes that optimization. Removing
the optimization allowed for removing the POP_ELEMENT and adjust_stack
functions.
This adds a benchmark to measure how much slower multiple
assignment is with the correct evaluation order.
This benchmark shows:
* 4-9% decrease for attribute sets
* 14-23% decrease for array member sets
* Basically same speed for local variable sets
Importantly, it shows no significant difference between the popped
(where return value of the multiple assignment is not needed) and
!popped (where return value of the multiple assignment is needed)
cases for attribute and array member sets. This indicates the
previous optimization, which was dropped in the evaluation
order fix and only affected the popped case, is not important to
performance.
Fixes [Bug #4443]
The most common use case for `bind_call` is to protect from core
methods being redefined, for instance a typical use:
```ruby
UNBOUND_METHOD_MODULE_NAME = Module.instance_method(:name)
def real_mod_name(mod)
UNBOUND_METHOD_MODULE_NAME.bind_call(mod)
end
```
But it's extremely common that the method wasn't actually redefined.
In such case we can avoid creating a new callable method entry,
and simply delegate to the receiver.
This result in a 1.5-2X speed-up for the fast path, and little to
no impact on the slowpath:
```
compare-ruby: ruby 3.1.0dev (2021-02-05T06:33:00Z master b2674c1fd7) [x86_64-darwin19]
built-ruby: ruby 3.1.0dev (2021-02-15T10:35:17Z bind-call-fastpath d687e06615) [x86_64-darwin19]
| |compare-ruby|built-ruby|
|:---------|-----------:|---------:|
|fastpath | 11.325M| 16.393M|
| | -| 1.45x|
|slowpath | 10.488M| 10.242M|
| | 1.02x| -|
```
* Add a benchmark-driver runner for Ractor
* Process.clock_gettime(Process:CLOCK_MONOTONIC) could be slow
in Ruby 3.0 Ractor
* Fetching Time could also be slow
* Fix a comment
* Assert overriding a private method
because the name "MJIT" is an internal code name, it's inconsistent with
--jit while they are related to each other, and I want to discourage future
JIT implementation-specific (e.g. MJIT-specific) APIs by this rename.
[Feature #17490]
Allocating an instance of a class uses the allocator for the class. When
the class has no allocator set, Ruby looks for it in the super class
(see rb_get_alloc_func()).
It's uncommon for classes created from Ruby code to ever have an
allocator set, so it's common during the allocation process to search
all the way to BasicObject from the class with which the allocation is
being performed. This makes creating instances of classes that have
long ancestry chains more expensive than creating instances of classes
have that shorter ancestry chains.
Setting the allocator at class creation time removes the need to perform
a search for the alloctor during allocation.
This is a breaking change for C-extensions that assume that classes
created from Ruby code have no allocator set. Libraries that setup a
class hierarchy in Ruby code and then set the allocator on some parent
class, for example, can experience breakage. This seems like an unusual
use case and hopefully it is rare or non-existent in practice.
Rails has many classes that have upwards of 60 elements in the ancestry
chain and benchmark shows a significant improvement for allocating with
a class that includes 64 modules.
```
pre: ruby 3.0.0dev (2020-11-12T14:39:27Z master 6325866421)
post: ruby 3.0.0dev (2020-11-12T20:15:30Z cut-allocator-lookup)
Comparison:
allocate_8_deep
post: 10336985.6 i/s
pre: 8691873.1 i/s - 1.19x slower
allocate_32_deep
post: 10423181.2 i/s
pre: 6264879.1 i/s - 1.66x slower
allocate_64_deep
post: 10541851.2 i/s
pre: 4936321.5 i/s - 2.14x slower
allocate_128_deep
post: 10451505.0 i/s
pre: 3031313.5 i/s - 3.45x slower
```
This benchmark demonstrates the performance of setting an instance
variable when the type of object is constantly changing. This benchmark
should give us an idea of the performance of ivar setting in a
polymorphic environment
When the inline cache is written, the iv table will contain an entry for
the instance variable. If we get an inline cache hit, then we know the
iv table must contain a value for the index written to the inline cache.
If the index in the inline cache is larger than the list on the object,
but *smaller* than the iv index table on the class, then we can just
eagerly allocate the iv list to be the same size as the iv index table.
This avoids duplicate work of checking frozen as well as looking up the
index for the particular instance variable name.
This PR improves the performance of `super` calls. While working on some
Rails optimizations jhawthorn discovered that `super` calls were slower
than expected.
The changes here do the following:
1) Adds a check for whether the call frame is not equal to the method
entry iseq. This avoids the `rb_obj_is_kind_of` check on the next line
which is quite slow. If the current call frame is equal to the method
entry we know we can't have an instance eval, etc.
2) Changes `FL_TEST` to `FL_TEST_RAW`. This is safe because we've
already done the check for `T_ICLASS` above.
3) Adds a benchmark for `T_ICLASS` super calls.
4) Note: makes a chage for `method_entry_cref` to use `const`.
On master the benchmarks showed that `super` is 1.76x slower. Our
changes improved the performance so that it is now only 1.36x slower.
Benchmark IPS:
```
Warming up --------------------------------------
super 244.918k i/100ms
method call 383.007k i/100ms
Calculating -------------------------------------
super 2.280M (± 6.7%) i/s - 11.511M in 5.071758s
method call 3.834M (± 4.9%) i/s - 19.150M in 5.008444s
Comparison:
method call: 3833648.3 i/s
super: 2279837.9 i/s - 1.68x (± 0.00) slower
```
With changes:
```
Warming up --------------------------------------
super 308.777k i/100ms
method call 375.051k i/100ms
Calculating -------------------------------------
super 2.951M (± 5.4%) i/s - 14.821M in 5.039592s
method call 3.551M (± 4.9%) i/s - 18.002M in 5.081695s
Comparison:
method call: 3551372.7 i/s
super: 2950557.9 i/s - 1.20x (± 0.00) slower
```
Ruby VM benchmarks also showed an improvement:
Existing `vm_super` benchmark`.
```
$ make benchmark ITEM=vm_super
| |compare-ruby|built-ruby|
|:---------|-----------:|---------:|
|vm_super | 21.555M| 37.819M|
| | -| 1.75x|
```
New `vm_iclass_super` benchmark:
```
$ make benchmark ITEM=vm_iclass_super
| |compare-ruby|built-ruby|
|:----------------|-----------:|---------:|
|vm_iclass_super | 1.669M| 3.683M|
| | -| 2.21x|
```
This is the benchmark script used for the benchmark-ips benchmarks:
```ruby
require "benchmark/ips"
class Foo
def zuper; end
def top; end
last_method = "top"
("A".."M").each do |module_name|
eval <<-EOM
module #{module_name}
def zuper; super; end
def #{module_name.downcase}
#{last_method}
end
end
prepend #{module_name}
EOM
last_method = module_name.downcase
end
end
foo = Foo.new
Benchmark.ips do |x|
x.report "super" do
foo.zuper
end
x.report "method call" do
foo.m
end
x.compare!
end
```
Co-authored-by: Aaron Patterson <tenderlove@ruby-lang.org>
Co-authored-by: John Hawthorn <john@hawthorn.email>
* Rewrite Kernel#tap with Ruby
This was good for VM too, but of course my intention is to unblock JIT's inlining of a block over yield
(inlining invokeyield has not been committed though).
* Fix test_settracefunc
About the :tap deletions, the :tap events are actually traced (we already have a TracePoint test for builtin methods),
but it's filtered out by tp.path == "xyzzy" (it became "<internal:kernel>"). We could trace tp.path == "<internal:kernel>"
cases too, but the lineno is impacted by kernel.rb changes and I didn't want to make it fragile for kernel.rb lineno changes.
for opt_* insns.
opt_eq handles rb_obj_equal inside opt_eq, and all other cfunc is
handled by opt_send_without_block. Therefore we can't decide which insn
should be generated by checking whether it's cfunc cc or not.
```
$ benchmark-driver -v --rbenv 'before --jit;after --jit' benchmark/mjit_opt_cc_insns.yml --repeat-count=4
before --jit: ruby 2.8.0dev (2020-06-26T05:21:43Z master 9dbc2294a6) +JIT [x86_64-linux]
after --jit: ruby 2.8.0dev (2020-06-26T06:30:18Z master 75cece1b0b) +JIT [x86_64-linux]
last_commit=Decide JIT-ed insn based on cached cfunc
Calculating -------------------------------------
before --jit after --jit
mjit_nil?(1) 73.878M 74.021M i/s - 40.000M times in 0.541432s 0.540391s
mjit_not(1) 72.635M 74.601M i/s - 40.000M times in 0.550702s 0.536187s
mjit_eq(1, nil) 7.331M 7.445M i/s - 8.000M times in 1.091211s 1.074596s
mjit_eq(nil, 1) 49.450M 64.711M i/s - 8.000M times in 0.161781s 0.123627s
Comparison:
mjit_nil?(1)
after --jit: 74020528.4 i/s
before --jit: 73878185.9 i/s - 1.00x slower
mjit_not(1)
after --jit: 74600882.0 i/s
before --jit: 72634507.6 i/s - 1.03x slower
mjit_eq(1, nil)
after --jit: 7444657.4 i/s
before --jit: 7331304.3 i/s - 1.02x slower
mjit_eq(nil, 1)
after --jit: 64710790.6 i/s
before --jit: 49449507.4 i/s - 1.31x slower
```
because opt_nil/opt_not/opt_eq populates cc even when it doesn't
fallback to opt_send_without_block because of vm_method_cfunc_is.
```
$ benchmark-driver -v --rbenv 'before --jit;after --jit' benchmark/mjit_opt_cc_insns.yml --repeat-count=4
before --jit: ruby 2.8.0dev (2020-06-22T08:11:24Z master d231b8f95b) +JIT [x86_64-linux]
after --jit: ruby 2.8.0dev (2020-06-22T08:53:27Z master e1125879ed) +JIT [x86_64-linux]
last_commit=Compile opt_send for opt_* only when cc has ISeq
Calculating -------------------------------------
before --jit after --jit
mjit_nil?(1) 54.106M 73.693M i/s - 40.000M times in 0.739288s 0.542795s
mjit_not(1) 53.398M 74.477M i/s - 40.000M times in 0.749090s 0.537075s
mjit_eq(1, nil) 7.427M 6.497M i/s - 8.000M times in 1.077136s 1.231326s
Comparison:
mjit_nil?(1)
after --jit: 73692594.3 i/s
before --jit: 54106108.4 i/s - 1.36x slower
mjit_not(1)
after --jit: 74477487.9 i/s
before --jit: 53398125.0 i/s - 1.39x slower
mjit_eq(1, nil)
before --jit: 7427105.9 i/s
after --jit: 6497063.0 i/s - 1.14x slower
```
Actually opt_eq becomes slower by this. Maybe it's indeed using
opt_send_without_block, but I'll approach that one in another commit.
These days I don't use `make benchmark`. The YAML files should be
executable with bare `benchmark-driver` CLI without passing
`RUBYOPT=-Ibenchmark/lib`.