oxilean_codegen/opt_peephole/
types.rs

1//! Types for the peephole optimisation pass.
2
3/// A single instruction in the peephole instruction model.
4///
5/// The instruction set is intentionally small: it covers the stack-machine
6/// primitives that appear in common IR back-ends and for which standard
7/// peephole identities are well-known.
8#[allow(dead_code)]
9#[derive(Debug, Clone, PartialEq, Eq)]
10pub enum PeepInstr {
11    /// Push an immediate integer constant.
12    Const(i64),
13    /// Integer addition (pops two, pushes one).
14    Add,
15    /// Integer subtraction (pops two, pushes one).
16    Sub,
17    /// Integer multiplication (pops two, pushes one).
18    Mul,
19    /// Integer division (pops two, pushes one).
20    Div,
21    /// Arithmetic negation (pops one, pushes one).
22    Neg,
23    /// Load the value of a named variable.
24    Load(String),
25    /// Store the top-of-stack into a named variable.
26    Store(String),
27    /// Conditional branch to the named label.
28    Branch(String),
29    /// Unconditional jump to the named label.
30    Jump(String),
31    /// Return from the current function.
32    Ret,
33    /// Duplicate the top-of-stack.
34    Dup,
35    /// Discard the top-of-stack.
36    Pop,
37    /// Swap the top two stack values.
38    Swap,
39    /// No-operation (placeholder; removed by the dead-nop rule).
40    Nop,
41}
42
43/// A pattern to be matched against a window of instructions.
44#[allow(dead_code)]
45#[derive(Debug, Clone)]
46pub struct PeepPattern {
47    /// The sequence of instructions that must match.
48    pub instrs: Vec<PeepInstr>,
49    /// Human-readable name for this pattern (used in diagnostics).
50    pub name: String,
51}
52
53/// The replacement sequence produced when a [`PeepPattern`] fires.
54#[allow(dead_code)]
55#[derive(Debug, Clone)]
56pub struct PeepReplacement {
57    /// The sequence that replaces the matched window.
58    pub instrs: Vec<PeepInstr>,
59    /// Human-readable name for this replacement (used in diagnostics).
60    pub name: String,
61}
62
63/// A complete peephole optimisation rule: pattern → replacement.
64#[allow(dead_code)]
65#[derive(Debug, Clone)]
66pub struct PeepRule {
67    /// The pattern to look for.
68    pub pattern: PeepPattern,
69    /// The replacement to emit when the pattern fires.
70    pub replacement: PeepReplacement,
71    /// Higher priority rules are tried first.
72    pub priority: i32,
73}
74
75/// The result returned by [`crate::opt_peephole::run_peephole`].
76#[allow(dead_code)]
77#[derive(Debug, Clone)]
78pub struct PeepResult {
79    /// The optimised instruction sequence.
80    pub instructions: Vec<PeepInstr>,
81    /// Names of the rules that were applied (in order of application).
82    pub rules_applied: Vec<String>,
83    /// The net number of instructions eliminated (original count minus final count).
84    pub reduction: usize,
85}
oxilean_codegen/opt_peephole/types.rs

oxilean_codegen/opt_peephole/
types.rs
