nushell/benches/benchmarks.rs
Devyn Cairns d7392f1f3b
Internal representation (IR) compiler and evaluator (#13330)
# Description

This PR adds an internal representation language to Nushell, offering an
alternative evaluator based on simple instructions, stream-containing
registers, and indexed control flow. The number of registers required is
determined statically at compile-time, and the fixed size required is
allocated upon entering the block.

Each instruction is associated with a span, which makes going backwards
from IR instructions to source code very easy.

Motivations for IR:

1. **Performance.** By simplifying the evaluation path and making it
more cache-friendly and branch predictor-friendly, code that does a lot
of computation in Nushell itself can be sped up a decent bit. Because
the IR is fairly easy to reason about, we can also implement
optimization passes in the future to eliminate and simplify code.
2. **Correctness.** The instructions mostly have very simple and
easily-specified behavior, so hopefully engine changes are a little bit
easier to reason about, and they can be specified in a more formal way
at some point. I have made an effort to document each of the
instructions in the docs for the enum itself in a reasonably specific
way. Some of the errors that would have happened during evaluation
before are now moved to the compilation step instead, because they don't
make sense to check during evaluation.
3. **As an intermediate target.** This is a good step for us to bring
the [`new-nu-parser`](https://github.com/nushell/new-nu-parser) in at
some point, as code generated from new AST can be directly compared to
code generated from old AST. If the IR code is functionally equivalent,
it will behave the exact same way.
4. **Debugging.** With a little bit more work, we can probably give
control over advancing the virtual machine that `IrBlock`s run on to
some sort of external driver, making things like breakpoints and single
stepping possible. Tools like `view ir` and [`explore
ir`](https://github.com/devyn/nu_plugin_explore_ir) make it easier than
before to see what exactly is going on with your Nushell code.

The goal is to eventually replace the AST evaluator entirely, once we're
sure it's working just as well. You can help dogfood this by running
Nushell with `$env.NU_USE_IR` set to some value. The environment
variable is checked when Nushell starts, so config runs with IR, or it
can also be set on a line at the REPL to change it dynamically. It is
also checked when running `do` in case within a script you want to just
run a specific piece of code with or without IR.

# Example

```nushell
view ir { |data|
  mut sum = 0
  for n in $data {
    $sum += $n
  }
  $sum
}
```
  
```gas
# 3 registers, 19 instructions, 0 bytes of data
   0: load-literal           %0, int(0)
   1: store-variable         var 904, %0 # let
   2: drain                  %0
   3: drop                   %0
   4: load-variable          %1, var 903
   5: iterate                %0, %1, end 15 # for, label(1), from(14:)
   6: store-variable         var 905, %0
   7: load-variable          %0, var 904
   8: load-variable          %2, var 905
   9: binary-op              %0, Math(Plus), %2
  10: span                   %0
  11: store-variable         var 904, %0
  12: load-literal           %0, nothing
  13: drain                  %0
  14: jump                   5
  15: drop                   %0          # label(0), from(5:)
  16: drain                  %0
  17: load-variable          %0, var 904
  18: return                 %0
```

# Benchmarks

All benchmarks run on a base model Mac Mini M1.

## Iterative Fibonacci sequence

This is about as best case as possible, making use of the much faster
control flow. Most code will not experience a speed improvement nearly
this large.

```nushell
def fib [n: int] {
  mut a = 0
  mut b = 1
  for _ in 2..=$n {
    let c = $a + $b
    $a = $b
    $b = $c
  }
  $b
}
use std bench
bench { 0..50 | each { |n| fib $n } }
```

IR disabled:

```
╭───────┬─────────────────╮
│ mean  │ 1ms 924µs 665ns │
│ min   │ 1ms 700µs 83ns  │
│ max   │ 3ms 450µs 125ns │
│ std   │ 395µs 759ns     │
│ times │ [list 50 items] │
╰───────┴─────────────────╯
```

IR enabled:

```
╭───────┬─────────────────╮
│ mean  │ 452µs 820ns     │
│ min   │ 427µs 417ns     │
│ max   │ 540µs 167ns     │
│ std   │ 17µs 158ns      │
│ times │ [list 50 items] │
╰───────┴─────────────────╯
```

![explore ir
view](https://github.com/nushell/nushell/assets/10729/d7bccc03-5222-461c-9200-0dce71b83b83)

##
[gradient_benchmark_no_check.nu](https://github.com/nushell/nu_scripts/blob/main/benchmarks/gradient_benchmark_no_check.nu)

IR disabled:

```
╭───┬──────────────────╮
│ 0 │ 27ms 929µs 958ns │
│ 1 │ 21ms 153µs 459ns │
│ 2 │ 18ms 639µs 666ns │
│ 3 │ 19ms 554µs 583ns │
│ 4 │ 13ms 383µs 375ns │
│ 5 │ 11ms 328µs 208ns │
│ 6 │  5ms 659µs 542ns │
╰───┴──────────────────╯
```

IR enabled:

```
╭───┬──────────────────╮
│ 0 │       22ms 662µs │
│ 1 │ 17ms 221µs 792ns │
│ 2 │ 14ms 786µs 708ns │
│ 3 │ 13ms 876µs 834ns │
│ 4 │  13ms 52µs 875ns │
│ 5 │ 11ms 269µs 666ns │
│ 6 │  6ms 942µs 500ns │
╰───┴──────────────────╯
```

##
[random-bytes.nu](https://github.com/nushell/nu_scripts/blob/main/benchmarks/random-bytes.nu)

I got pretty random results out of this benchmark so I decided not to
include it. Not clear why.

# User-Facing Changes
- IR compilation errors may appear even if the user isn't evaluating
with IR.
- IR evaluation can be enabled by setting the `NU_USE_IR` environment
variable to any value.
- New command `view ir` pretty-prints the IR for a block, and `view ir
--json` can be piped into an external tool like [`explore
ir`](https://github.com/devyn/nu_plugin_explore_ir).

# Tests + Formatting
All tests are passing with `NU_USE_IR=1`, and I've added some more eval
tests to compare the results for some very core operations. I will
probably want to add some more so we don't have to always check
`NU_USE_IR=1 toolkit test --workspace` on a regular basis.

# After Submitting
- [ ] release notes
- [ ] further documentation of instructions?
- [ ] post-release: publish `nu_plugin_explore_ir`
2024-07-10 17:33:59 -07:00

493 lines
13 KiB
Rust

use nu_cli::{eval_source, evaluate_commands};
use nu_plugin_core::{Encoder, EncodingType};
use nu_plugin_protocol::{PluginCallResponse, PluginOutput};
use nu_protocol::{
engine::{EngineState, Stack},
PipelineData, Signals, Span, Spanned, Value,
};
use nu_std::load_standard_library;
use nu_utils::{get_default_config, get_default_env};
use std::{
rc::Rc,
sync::{atomic::AtomicBool, Arc},
};
use std::hint::black_box;
use tango_bench::{benchmark_fn, tango_benchmarks, tango_main, IntoBenchmarks};
fn load_bench_commands() -> EngineState {
nu_command::add_shell_command_context(nu_cmd_lang::create_default_context())
}
fn setup_engine() -> EngineState {
let mut engine_state = load_bench_commands();
let cwd = std::env::current_dir()
.unwrap()
.into_os_string()
.into_string()
.unwrap();
// parsing config.nu breaks without PWD set, so set a valid path
engine_state.add_env_var("PWD".into(), Value::string(cwd, Span::test_data()));
engine_state.generate_nu_constant();
engine_state
}
fn setup_stack_and_engine_from_command(command: &str) -> (Stack, EngineState) {
let mut engine = setup_engine();
let commands = Spanned {
span: Span::unknown(),
item: command.to_string(),
};
let mut stack = Stack::new();
// Support running benchmarks with IR mode
stack.use_ir = std::env::var_os("NU_USE_IR").is_some();
evaluate_commands(
&commands,
&mut engine,
&mut stack,
PipelineData::empty(),
Default::default(),
)
.unwrap();
(stack, engine)
}
// generate a new table data with `row_cnt` rows, `col_cnt` columns.
fn encoding_test_data(row_cnt: usize, col_cnt: usize) -> Value {
let record = Value::test_record(
(0..col_cnt)
.map(|x| (format!("col_{x}"), Value::test_int(x as i64)))
.collect(),
);
Value::list(vec![record; row_cnt], Span::test_data())
}
fn bench_command(
name: &str,
command: &str,
stack: Stack,
engine: EngineState,
) -> impl IntoBenchmarks {
let commands = Spanned {
span: Span::unknown(),
item: command.to_string(),
};
[benchmark_fn(name, move |b| {
let commands = commands.clone();
let stack = stack.clone();
let engine = engine.clone();
b.iter(move || {
let mut stack = stack.clone();
let mut engine = engine.clone();
#[allow(clippy::unit_arg)]
black_box(
evaluate_commands(
&commands,
&mut engine,
&mut stack,
PipelineData::empty(),
Default::default(),
)
.unwrap(),
);
})
})]
}
fn bench_eval_source(
name: &str,
fname: String,
source: Vec<u8>,
stack: Stack,
engine: EngineState,
) -> impl IntoBenchmarks {
[benchmark_fn(name, move |b| {
let stack = stack.clone();
let engine = engine.clone();
let fname = fname.clone();
let source = source.clone();
b.iter(move || {
let mut stack = stack.clone();
let mut engine = engine.clone();
let fname: &str = &fname.clone();
let source: &[u8] = &source.clone();
black_box(eval_source(
&mut engine,
&mut stack,
source,
fname,
PipelineData::empty(),
false,
));
})
})]
}
/// Load the standard library into the engine.
fn bench_load_standard_lib() -> impl IntoBenchmarks {
[benchmark_fn("load_standard_lib", move |b| {
let engine = setup_engine();
b.iter(move || {
let mut engine = engine.clone();
load_standard_library(&mut engine)
})
})]
}
fn create_flat_record_string(n: i32) -> String {
let mut s = String::from("let record = {");
for i in 0..n {
s.push_str(&format!("col_{}: {}", i, i));
if i < n - 1 {
s.push_str(", ");
}
}
s.push('}');
s
}
fn create_nested_record_string(depth: i32) -> String {
let mut s = String::from("let record = {");
for _ in 0..depth {
s.push_str("col: {");
}
s.push_str("col_final: 0");
for _ in 0..depth {
s.push('}');
}
s.push('}');
s
}
fn create_example_table_nrows(n: i32) -> String {
let mut s = String::from("let table = [[foo bar baz]; ");
for i in 0..n {
s.push_str(&format!("[0, 1, {i}]"));
if i < n - 1 {
s.push_str(", ");
}
}
s.push(']');
s
}
fn bench_record_create(n: i32) -> impl IntoBenchmarks {
bench_command(
&format!("record_create_{n}"),
&create_flat_record_string(n),
Stack::new(),
setup_engine(),
)
}
fn bench_record_flat_access(n: i32) -> impl IntoBenchmarks {
let setup_command = create_flat_record_string(n);
let (stack, engine) = setup_stack_and_engine_from_command(&setup_command);
bench_command(
&format!("record_flat_access_{n}"),
"$record.col_0 | ignore",
stack,
engine,
)
}
fn bench_record_nested_access(n: i32) -> impl IntoBenchmarks {
let setup_command = create_nested_record_string(n);
let (stack, engine) = setup_stack_and_engine_from_command(&setup_command);
let nested_access = ".col".repeat(n as usize);
bench_command(
&format!("record_nested_access_{n}"),
&format!("$record{} | ignore", nested_access),
stack,
engine,
)
}
fn bench_table_create(n: i32) -> impl IntoBenchmarks {
bench_command(
&format!("table_create_{n}"),
&create_example_table_nrows(n),
Stack::new(),
setup_engine(),
)
}
fn bench_table_get(n: i32) -> impl IntoBenchmarks {
let setup_command = create_example_table_nrows(n);
let (stack, engine) = setup_stack_and_engine_from_command(&setup_command);
bench_command(
&format!("table_get_{n}"),
"$table | get bar | math sum | ignore",
stack,
engine,
)
}
fn bench_table_select(n: i32) -> impl IntoBenchmarks {
let setup_command = create_example_table_nrows(n);
let (stack, engine) = setup_stack_and_engine_from_command(&setup_command);
bench_command(
&format!("table_select_{n}"),
"$table | select foo baz | ignore",
stack,
engine,
)
}
fn bench_eval_interleave(n: i32) -> impl IntoBenchmarks {
let engine = setup_engine();
let stack = Stack::new();
bench_command(
&format!("eval_interleave_{n}"),
&format!("seq 1 {n} | wrap a | interleave {{ seq 1 {n} | wrap b }} | ignore"),
stack,
engine,
)
}
fn bench_eval_interleave_with_interrupt(n: i32) -> impl IntoBenchmarks {
let mut engine = setup_engine();
engine.set_signals(Signals::new(Arc::new(AtomicBool::new(false))));
let stack = Stack::new();
bench_command(
&format!("eval_interleave_with_interrupt_{n}"),
&format!("seq 1 {n} | wrap a | interleave {{ seq 1 {n} | wrap b }} | ignore"),
stack,
engine,
)
}
fn bench_eval_for(n: i32) -> impl IntoBenchmarks {
let engine = setup_engine();
let stack = Stack::new();
bench_command(
&format!("eval_for_{n}"),
&format!("(for $x in (1..{n}) {{ 1 }}) | ignore"),
stack,
engine,
)
}
fn bench_eval_each(n: i32) -> impl IntoBenchmarks {
let engine = setup_engine();
let stack = Stack::new();
bench_command(
&format!("eval_each_{n}"),
&format!("(1..{n}) | each {{|_| 1 }} | ignore"),
stack,
engine,
)
}
fn bench_eval_par_each(n: i32) -> impl IntoBenchmarks {
let engine = setup_engine();
let stack = Stack::new();
bench_command(
&format!("eval_par_each_{n}"),
&format!("(1..{}) | par-each -t 2 {{|_| 1 }} | ignore", n),
stack,
engine,
)
}
fn bench_eval_default_config() -> impl IntoBenchmarks {
let default_env = get_default_config().as_bytes().to_vec();
let fname = "default_config.nu".to_string();
bench_eval_source(
"eval_default_config",
fname,
default_env,
Stack::new(),
setup_engine(),
)
}
fn bench_eval_default_env() -> impl IntoBenchmarks {
let default_env = get_default_env().as_bytes().to_vec();
let fname = "default_env.nu".to_string();
bench_eval_source(
"eval_default_env",
fname,
default_env,
Stack::new(),
setup_engine(),
)
}
fn encode_json(row_cnt: usize, col_cnt: usize) -> impl IntoBenchmarks {
let test_data = Rc::new(PluginOutput::CallResponse(
0,
PluginCallResponse::value(encoding_test_data(row_cnt, col_cnt)),
));
let encoder = Rc::new(EncodingType::try_from_bytes(b"json").unwrap());
[benchmark_fn(
format!("encode_json_{}_{}", row_cnt, col_cnt),
move |b| {
let encoder = encoder.clone();
let test_data = test_data.clone();
b.iter(move || {
let mut res = Vec::new();
encoder.encode(&*test_data, &mut res).unwrap();
})
},
)]
}
fn encode_msgpack(row_cnt: usize, col_cnt: usize) -> impl IntoBenchmarks {
let test_data = Rc::new(PluginOutput::CallResponse(
0,
PluginCallResponse::value(encoding_test_data(row_cnt, col_cnt)),
));
let encoder = Rc::new(EncodingType::try_from_bytes(b"msgpack").unwrap());
[benchmark_fn(
format!("encode_msgpack_{}_{}", row_cnt, col_cnt),
move |b| {
let encoder = encoder.clone();
let test_data = test_data.clone();
b.iter(move || {
let mut res = Vec::new();
encoder.encode(&*test_data, &mut res).unwrap();
})
},
)]
}
fn decode_json(row_cnt: usize, col_cnt: usize) -> impl IntoBenchmarks {
let test_data = PluginOutput::CallResponse(
0,
PluginCallResponse::value(encoding_test_data(row_cnt, col_cnt)),
);
let encoder = EncodingType::try_from_bytes(b"json").unwrap();
let mut res = vec![];
encoder.encode(&test_data, &mut res).unwrap();
[benchmark_fn(
format!("decode_json_{}_{}", row_cnt, col_cnt),
move |b| {
let res = res.clone();
b.iter(move || {
let mut binary_data = std::io::Cursor::new(res.clone());
binary_data.set_position(0);
let _: Result<Option<PluginOutput>, _> =
black_box(encoder.decode(&mut binary_data));
})
},
)]
}
fn decode_msgpack(row_cnt: usize, col_cnt: usize) -> impl IntoBenchmarks {
let test_data = PluginOutput::CallResponse(
0,
PluginCallResponse::value(encoding_test_data(row_cnt, col_cnt)),
);
let encoder = EncodingType::try_from_bytes(b"msgpack").unwrap();
let mut res = vec![];
encoder.encode(&test_data, &mut res).unwrap();
[benchmark_fn(
format!("decode_msgpack_{}_{}", row_cnt, col_cnt),
move |b| {
let res = res.clone();
b.iter(move || {
let mut binary_data = std::io::Cursor::new(res.clone());
binary_data.set_position(0);
let _: Result<Option<PluginOutput>, _> =
black_box(encoder.decode(&mut binary_data));
})
},
)]
}
tango_benchmarks!(
bench_load_standard_lib(),
// Data types
// Record
bench_record_create(1),
bench_record_create(10),
bench_record_create(100),
bench_record_create(1_000),
bench_record_flat_access(1),
bench_record_flat_access(10),
bench_record_flat_access(100),
bench_record_flat_access(1_000),
bench_record_nested_access(1),
bench_record_nested_access(2),
bench_record_nested_access(4),
bench_record_nested_access(8),
bench_record_nested_access(16),
bench_record_nested_access(32),
bench_record_nested_access(64),
bench_record_nested_access(128),
// Table
bench_table_create(1),
bench_table_create(10),
bench_table_create(100),
bench_table_create(1_000),
bench_table_get(1),
bench_table_get(10),
bench_table_get(100),
bench_table_get(1_000),
bench_table_select(1),
bench_table_select(10),
bench_table_select(100),
bench_table_select(1_000),
// Eval
// Interleave
bench_eval_interleave(100),
bench_eval_interleave(1_000),
bench_eval_interleave(10_000),
bench_eval_interleave_with_interrupt(100),
bench_eval_interleave_with_interrupt(1_000),
bench_eval_interleave_with_interrupt(10_000),
// For
bench_eval_for(1),
bench_eval_for(10),
bench_eval_for(100),
bench_eval_for(1_000),
bench_eval_for(10_000),
// Each
bench_eval_each(1),
bench_eval_each(10),
bench_eval_each(100),
bench_eval_each(1_000),
bench_eval_each(10_000),
// Par-Each
bench_eval_par_each(1),
bench_eval_par_each(10),
bench_eval_par_each(100),
bench_eval_par_each(1_000),
bench_eval_par_each(10_000),
// Config
bench_eval_default_config(),
// Env
bench_eval_default_env(),
// Encode
// Json
encode_json(100, 5),
encode_json(10000, 15),
// MsgPack
encode_msgpack(100, 5),
encode_msgpack(10000, 15),
// Decode
// Json
decode_json(100, 5),
decode_json(10000, 15),
// MsgPack
decode_msgpack(100, 5),
decode_msgpack(10000, 15)
);
tango_main!();