Optimization experiments

Cargo.lock

@@ -196,6 +196,7 @@ dependencies = [
  "rand",
  "serde",
  "serde_json",
+ "smallvec",
 ]
 
 [[package]]
@@ -486,6 +487,15 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "smallvec"
+version = "1.13.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3c5e1a9a646d36c3599cd173a41282daf47c44583ad367b8e6837255952e5c67"
+dependencies = [
+ "serde",
+]
+
 [[package]]
 name = "spin"
 version = "0.9.8"

README.md

@@ -121,8 +121,9 @@ assigning each argument a register and associating the register with the local.
 
 When generating instructions for a register-based virtual machine, there are opportunities to
 optimize the generated code by using fewer instructions or fewer registers. While it is best to
-output optimal code in the first place, it is not always possible. Dust's compiler uses simple
+output optimal code in the first place, it is not always possible. Dust's compiler modifies the
-functions that modify isolated sections of the instruction list through a mutable reference.
+instruction list during parsing to apply optimizations before the chunk is completed. There is no
+separate optimization pass, and the compiler cannot be run in a mode that disables optimizations.
 
 #### Type Checking
 

bench/assets/count_to_one_billion.ds

@@ -0,0 +1,5 @@
+let mut i = 0
+
+while i < 100_000_000 {
+    i += 1
+}

bench/assets/count_to_one_billion.js

@@ -0,0 +1,5 @@
+var i = 0;
+
+while (i < 1_000_000_000) {
+  i++;
+}

dust-lang/Cargo.toml

@@ -18,6 +18,7 @@ serde_json = "1.0.117"
 getrandom = { version = "0.2", features = [
     "js",
 ] } # Indirect dependency, for wasm builds
+smallvec = { version = "1.13.2", features = ["serde"] }
 
 [dev-dependencies]
 env_logger = "0.11.5"

dust-lang/src/chunk.rs

@@ -7,6 +7,7 @@
 use std::fmt::{self, Debug, Display, Write};
 
 use serde::{Deserialize, Serialize};
+use smallvec::SmallVec;
 
 use crate::{ConcreteValue, Disassembler, FunctionType, Instruction, Scope, Span, Type};
 
@@ -18,18 +19,18 @@ pub struct Chunk {
     name: Option<String>,
     r#type: FunctionType,
 
-    instructions: Vec<(Instruction, Span)>,
+    instructions: SmallVec<[(Instruction, Span); 32]>,
-    constants: Vec<ConcreteValue>,
+    constants: SmallVec<[ConcreteValue; 16]>,
-    locals: Vec<Local>,
+    locals: SmallVec<[Local; 8]>,
 }
 
 impl Chunk {
     pub fn new(name: Option<String>) -> Self {
         Self {
             name,
-            instructions: Vec::new(),
+            instructions: SmallVec::new(),
-            constants: Vec::new(),
+            constants: SmallVec::new(),
-            locals: Vec::new(),
+            locals: SmallVec::new(),
             r#type: FunctionType {
                 type_parameters: None,
                 value_parameters: None,
@@ -48,9 +49,9 @@ impl Chunk {
         Self {
             name,
             r#type,
-            instructions,
+            instructions: instructions.into(),
-            constants,
+            constants: constants.into(),
-            locals,
+            locals: locals.into(),
         }
     }
 
@@ -70,18 +71,32 @@ impl Chunk {
         self.instructions.is_empty()
     }
 
-    pub fn constants(&self) -> &Vec<ConcreteValue> {
+    pub fn constants(&self) -> &SmallVec<[ConcreteValue; 16]> {
         &self.constants
     }
 
-    pub fn instructions(&self) -> &Vec<(Instruction, Span)> {
+    pub fn instructions(&self) -> &SmallVec<[(Instruction, Span); 32]> {
         &self.instructions
     }
 
-    pub fn locals(&self) -> &Vec<Local> {
+    pub fn locals(&self) -> &SmallVec<[Local; 8]> {
         &self.locals
     }
 
+    pub fn stack_size(&self) -> usize {
+        self.instructions()
+            .iter()
+            .rev()
+            .find_map(|(instruction, _)| {
+                if instruction.yields_value() {
+                    Some(instruction.a() as usize)
+                } else {
+                    None
+                }
+            })
+            .unwrap_or(0)
+    }
+
     pub fn disassembler(&self) -> Disassembler {
         Disassembler::new(self)
     }

dust-lang/src/compiler.rs

@@ -505,13 +505,19 @@ impl<'src> Compiler<'src> {
         if let Token::Integer(text) = self.current_token {
             self.advance()?;
 
-            let integer = text
+            let mut integer_value = 0_i64;
-                .parse::<i64>()
+
-                .map_err(|error| CompileError::ParseIntError {
+            for digit in text.chars() {
-                    error,
+                let digit = if let Some(digit) = digit.to_digit(10) {
-                    position: self.previous_position,
+                    digit as i64
-                })?;
+                } else {
-            let value = ConcreteValue::Integer(integer);
+                    continue;
+                };
+
+                integer_value = integer_value * 10 + digit;
+            }
+
+            let value = ConcreteValue::Integer(integer_value);
 
             self.emit_constant(value, position)?;
 
@@ -1519,7 +1525,7 @@ impl<'src> Compiler<'src> {
         self.current_position = function_compiler.current_position;
 
         let function =
-            ConcreteValue::Function(function_compiler.finish(None, value_parameters.clone()));
+            ConcreteValue::function(function_compiler.finish(None, value_parameters.clone()));
         let constant_index = self.push_or_get_constant(function);
         let register = self.next_register();
         let function_type = FunctionType {

dust-lang/src/lexer.rs

@@ -239,7 +239,7 @@ impl<'src> Lexer<'src> {
                 }
             }
 
-            if c.is_ascii_digit() {
+            if c.is_ascii_digit() || c == '_' {
                 self.next_char();
             } else {
                 break;

dust-lang/src/value/abstract_value.rs

@@ -19,7 +19,7 @@ impl AbstractValue {
 
     pub fn to_concrete_owned(&self, vm: &Vm) -> Result<ConcreteValue, VmError> {
         match self {
-            AbstractValue::FunctionSelf => Ok(ConcreteValue::Function(vm.chunk().clone())),
+            AbstractValue::FunctionSelf => Ok(ConcreteValue::function(vm.chunk().clone())),
             AbstractValue::List { items, .. } => {
                 let mut resolved_items = Vec::with_capacity(items.len());
 

dust-lang/src/value/concrete_value.rs

@@ -12,7 +12,7 @@ pub enum ConcreteValue {
     Byte(u8),
     Character(char),
     Float(f64),
-    Function(Chunk),
+    Function(Box<Chunk>),
     Integer(i64),
     List(Vec<ConcreteValue>),
     Range(RangeValue),
@@ -28,6 +28,10 @@ impl ConcreteValue {
         ValueRef::Concrete(self)
     }
 
+    pub fn function(chunk: Chunk) -> Self {
+        ConcreteValue::Function(Box::new(chunk))
+    }
+
     pub fn list<T: Into<Vec<ConcreteValue>>>(into_list: T) -> Self {
         ConcreteValue::List(into_list.into())
     }

dust-lang/src/value/mod.rs

@@ -80,7 +80,7 @@ impl ValueRef<'_> {
     pub fn add(&self, other: ValueRef) -> Result<Value, ValueError> {
         match (self, other) {
             (ValueRef::Concrete(left), ValueRef::Concrete(right)) => {
-                left.add(right).map(|result| result.to_value())
+                left.add(right).map(Value::Concrete)
             }
             _ => Err(ValueError::CannotAdd(self.to_owned(), other.to_owned())),
         }
@@ -89,7 +89,7 @@ impl ValueRef<'_> {
     pub fn subtract(&self, other: ValueRef) -> Result<Value, ValueError> {
         match (self, other) {
             (ValueRef::Concrete(left), ValueRef::Concrete(right)) => {
-                left.subtract(right).map(|result| result.to_value())
+                left.subtract(right).map(Value::Concrete)
             }
             _ => Err(ValueError::CannotSubtract(
                 self.to_owned(),
@@ -101,7 +101,7 @@ impl ValueRef<'_> {
     pub fn multiply(&self, other: ValueRef) -> Result<Value, ValueError> {
         match (self, other) {
             (ValueRef::Concrete(left), ValueRef::Concrete(right)) => {
-                left.multiply(right).map(|result| result.to_value())
+                left.multiply(right).map(Value::Concrete)
             }
             _ => Err(ValueError::CannotMultiply(
                 self.to_owned(),
@@ -113,7 +113,7 @@ impl ValueRef<'_> {
     pub fn divide(&self, other: ValueRef) -> Result<Value, ValueError> {
         match (self, other) {
             (ValueRef::Concrete(left), ValueRef::Concrete(right)) => {
-                left.divide(right).map(|result| result.to_value())
+                left.divide(right).map(Value::Concrete)
             }
             _ => Err(ValueError::CannotDivide(self.to_owned(), other.to_owned())),
         }
@@ -122,7 +122,7 @@ impl ValueRef<'_> {
     pub fn modulo(&self, other: ValueRef) -> Result<Value, ValueError> {
         match (self, other) {
             (ValueRef::Concrete(left), ValueRef::Concrete(right)) => {
-                left.modulo(right).map(|result| result.to_value())
+                left.modulo(right).map(Value::Concrete)
             }
             _ => Err(ValueError::CannotModulo(self.to_owned(), other.to_owned())),
         }
@@ -130,18 +130,14 @@ impl ValueRef<'_> {
 
     pub fn negate(&self) -> Result<Value, ValueError> {
         match self {
-            ValueRef::Concrete(concrete_value) => {
+            ValueRef::Concrete(concrete_value) => concrete_value.negate().map(Value::Concrete),
-                concrete_value.negate().map(|result| result.to_value())
-            }
             _ => Err(ValueError::CannotNegate(self.to_owned())),
         }
     }
 
     pub fn not(&self) -> Result<Value, ValueError> {
         match self {
-            ValueRef::Concrete(concrete_value) => {
+            ValueRef::Concrete(concrete_value) => concrete_value.not().map(Value::Concrete),
-                concrete_value.not().map(|result| result.to_value())
-            }
             _ => Err(ValueError::CannotNot(self.to_owned())),
         }
     }
@@ -149,7 +145,7 @@ impl ValueRef<'_> {
     pub fn equal(&self, other: ValueRef) -> Result<Value, ValueError> {
         match (self, other) {
             (ValueRef::Concrete(left), ValueRef::Concrete(right)) => {
-                left.equal(right).map(|result| result.to_value())
+                left.equal(right).map(Value::Concrete)
             }
             _ => Err(ValueError::CannotCompare(self.to_owned(), other.to_owned())),
         }
@@ -158,7 +154,7 @@ impl ValueRef<'_> {
     pub fn less_than(&self, other: ValueRef) -> Result<Value, ValueError> {
         match (self, other) {
             (ValueRef::Concrete(left), ValueRef::Concrete(right)) => {
-                left.less_than(right).map(|result| result.to_value())
+                left.less_than(right).map(Value::Concrete)
             }
             _ => Err(ValueError::CannotCompare(self.to_owned(), other.to_owned())),
         }
@@ -166,9 +162,9 @@ impl ValueRef<'_> {
 
     pub fn less_than_or_equal(&self, other: ValueRef) -> Result<Value, ValueError> {
         match (self, other) {
-            (ValueRef::Concrete(left), ValueRef::Concrete(right)) => left
+            (ValueRef::Concrete(left), ValueRef::Concrete(right)) => {
-                .less_than_or_equal(right)
+                left.less_than_or_equal(right).map(Value::Concrete)
-                .map(|result| result.to_value()),
+            }
             _ => Err(ValueError::CannotCompare(self.to_owned(), other.to_owned())),
         }
     }

dust-lang/src/vm.rs

@@ -5,6 +5,8 @@ use std::{
     io,
 };
 
+use smallvec::{smallvec, SmallVec};
+
 use crate::{
     compile, instruction::*, AbstractValue, AnnotatedError, Argument, Chunk, ConcreteValue,
     Destination, DustError, Instruction, NativeFunctionError, Operation, Span, Value, ValueError,
@@ -25,9 +27,9 @@ pub fn run(source: &str) -> Result<Option<ConcreteValue>, DustError> {
 #[derive(Debug)]
 pub struct Vm<'a> {
     chunk: &'a Chunk,
-    stack: Vec<Register>,
+    stack: SmallVec<[Register; 64]>,
     parent: Option<&'a Vm<'a>>,
-    local_definitions: Vec<Option<u16>>,
+    local_definitions: SmallVec<[Option<u16>; 16]>,
 
     ip: usize,
     last_assigned_register: Option<u16>,
@@ -35,14 +37,14 @@ pub struct Vm<'a> {
 }
 
 impl<'a> Vm<'a> {
-    const STACK_LIMIT: usize = u16::MAX as usize;
+    const STACK_LIMIT: u16 = u16::MAX;
 
     pub fn new(chunk: &'a Chunk, parent: Option<&'a Vm<'a>>) -> Self {
         Self {
             chunk,
-            stack: Vec::new(),
+            stack: smallvec![Register::Empty; chunk.stack_size()],
             parent,
-            local_definitions: vec![None; chunk.locals().len()],
+            local_definitions: smallvec![None; chunk.locals().len()],
             ip: 0,
             last_assigned_register: None,
             current_position: Span(0, 0),
@@ -643,11 +645,9 @@ impl<'a> Vm<'a> {
         Ok(value_ref)
     }
 
+    #[inline(always)]
     fn set_register(&mut self, to_register: u16, register: Register) -> Result<(), VmError> {
-        self.last_assigned_register = Some(to_register);
+        let length = self.stack.len() as u16;
-
-        let length = self.stack.len();
-        let to_register = to_register as usize;
 
         if length == Self::STACK_LIMIT {
             return Err(VmError::StackOverflow {
@@ -659,16 +659,12 @@ impl<'a> Vm<'a> {
             Ordering::Less => {
                 log::trace!("Change R{to_register} to {register}");
 
-                self.stack[to_register] = register;
+                self.stack[to_register as usize] = register;
-
-                Ok(())
             }
             Ordering::Equal => {
                 log::trace!("Set R{to_register} to {register}");
 
                 self.stack.push(register);
-
-                Ok(())
             }
             Ordering::Greater => {
                 let difference = to_register - length;
@@ -682,10 +678,12 @@ impl<'a> Vm<'a> {
                 log::trace!("Set R{to_register} to {register}");
 
                 self.stack.push(register);
-
-                Ok(())
             }
         }
+
+        self.last_assigned_register = Some(to_register);
+
+        Ok(())
     }
 
     fn get_constant(&self, constant_index: u16) -> Result<&ConcreteValue, VmError> {

dust-lang/tests/functions.rs

@@ -6,7 +6,7 @@ fn function() {
 
     assert_eq!(
         run(source),
-        Ok(Some(ConcreteValue::Function(Chunk::with_data(
+        Ok(Some(ConcreteValue::function(Chunk::with_data(
             None,
             FunctionType {
                 type_parameters: None,
@@ -70,7 +70,7 @@ fn function_call() {
                 (Instruction::r#return(true), Span(41, 41)),
             ],
             vec![
-                ConcreteValue::Function(Chunk::with_data(
+                ConcreteValue::function(Chunk::with_data(
                     None,
                     FunctionType {
                         type_parameters: None,
@@ -126,7 +126,7 @@ fn function_declaration() {
                 (Instruction::r#return(false), Span(40, 40))
             ],
             vec![
-                ConcreteValue::Function(Chunk::with_data(
+                ConcreteValue::function(Chunk::with_data(
                     Some("add".to_string()),
                     FunctionType {
                         type_parameters: None,

examples/assets/count.js

@@ -1,5 +0,0 @@
-var i = 0;
-
-while (i < 10000) {
-  i++;
-}

perf.data.old

@@ -0,0 +1,22 @@
+# started on Tue Dec  3 23:57:01 2024
+
+
+ Performance counter stats for 'target/release/dust bench/assets/count_to_one_billion.ds':
+
+          3,821.33 msec task-clock:u                     #    1.000 CPUs utilized             
+                 0      context-switches:u               #    0.000 /sec                      
+                 0      cpu-migrations:u                 #    0.000 /sec                      
+               128      page-faults:u                    #   33.496 /sec                      
+    19,568,365,731      cycles:u                         #    5.121 GHz                       
+        22,811,191      stalled-cycles-frontend:u        #    0.12% frontend cycles idle      
+    70,300,518,284      instructions:u                   #    3.59  insn per cycle            
+                                                  #    0.00  stalled cycles per insn   
+    12,500,111,636      branches:u                       #    3.271 G/sec                     
+            19,795      branch-misses:u                  #    0.00% of all branches           
+
+       3.822391878 seconds time elapsed
+
+       3.811230000 seconds user
+       0.000999000 seconds sys
+
+