make stmt a single word big

rust2/benches/opts.rs

@@ -35,12 +35,14 @@ fn optimized(c: &mut Criterion) {
     let loopremove = include_str!("loopremove.bf");
     let twinkle = include_str!("twinkle.bf");
     let bottles = include_str!("bottles.bf");
+    let hanoi = include_str!("hanoi.bf");
 
     c.bench_function("fizzbuzz", |b| b.iter(|| run_bf(black_box(fizzbuzz))));
     c.bench_function("bench", |b| b.iter(|| run_bf(black_box(bench))));
     c.bench_function("loopremove", |b| b.iter(|| run_bf(black_box(loopremove))));
     c.bench_function("twinkle", |b| b.iter(|| run_bf(black_box(twinkle))));
     c.bench_function("bottles", |b| b.iter(|| run_bf(black_box(bottles))));
+    c.bench_function("hanoi", |b| b.iter(|| run_bf(black_box(hanoi))));
 }
 
 criterion_group!(benches, optimized);

rust2/src/codegen.rs

@@ -25,16 +25,18 @@ use bumpalo::Bump;
 pub enum Stmt {
     Add(u8),
     Sub(u8),
-    Right(usize),
-    Left(usize),
+    Right(u32),
+    Left(u32),
     Out,
     In,
     SetNull,
-    JmpIfZero(usize),
-    JmpIfNonZero(usize),
+    JmpIfZero(u32),
+    JmpIfNonZero(u32),
     End,
 }
 
+const _: [(); 8] = [(); std::mem::size_of::<Stmt>()];
+
 #[derive(Debug, Clone)]
 pub struct Code<'c> {
     stmts: Vec<Stmt, &'c Bump>,
@@ -76,8 +78,8 @@ fn ir_to_stmt<'c>(code: &mut Code<'c>, ir_stmt: &IrStmt<'_>) {
     let stmt = match &ir_stmt.kind {
         StmtKind::Add(n) => Stmt::Add(*n),
         StmtKind::Sub(n) => Stmt::Sub(*n),
-        StmtKind::Right(n) => Stmt::Right(*n),
-        StmtKind::Left(n) => Stmt::Left(*n),
+        StmtKind::Right(n) => Stmt::Right(u32::try_from(*n).unwrap()),
+        StmtKind::Left(n) => Stmt::Left(u32::try_from(*n).unwrap()),
         StmtKind::Out => Stmt::Out,
         StmtKind::In => Stmt::In,
         StmtKind::SetNull => Stmt::SetNull,
@@ -90,14 +92,15 @@ fn ir_to_stmt<'c>(code: &mut Code<'c>, ir_stmt: &IrStmt<'_>) {
             generate_stmts(code, &instr.stmts);
             // if the loop body is empty, we jmp to ourselves, which is an infinite loop - as expected
             let first_loop_body_idx = skip_jmp_idx + 1;
-            code.stmts.push(Stmt::JmpIfNonZero(first_loop_body_idx));
+            code.stmts
+                .push(Stmt::JmpIfNonZero(first_loop_body_idx.try_into().unwrap()));
             code.debug.push(ir_stmt.span);
 
             // there will always at least be an `End` instruction after the loop
             let after_loop_idx = code.stmts.len();
 
             // fix the placeholder with the actual index
-            code.stmts[skip_jmp_idx] = Stmt::JmpIfZero(after_loop_idx);
+            code.stmts[skip_jmp_idx] = Stmt::JmpIfZero(after_loop_idx.try_into().unwrap());
 
             return;
         }

rust2/src/codegen_interpreter.rs

@@ -2,15 +2,15 @@ use crate::codegen::{Code, Stmt};
 use std::io::{Read, Write};
 use std::num::Wrapping;
 
-const MEM_SIZE: usize = 32_000;
+const MEM_SIZE: u32 = 32_000;
 
-type Memory = [Wrapping<u8>; MEM_SIZE];
+type Memory = [Wrapping<u8>; MEM_SIZE as usize];
 
 // TODO maybe repr(C) to prevent field reordering?
 struct Interpreter<'c, W, R> {
     code: &'c Code<'c>,
-    ip: usize,
-    ptr: usize,
+    ip: u32,
+    ptr: u32,
     stdout: W,
     stdin: R,
     mem: Memory,
@@ -27,7 +27,7 @@ where
         ptr: 0,
         stdout,
         stdin,
-        mem: [Wrapping(0u8); MEM_SIZE],
+        mem: [Wrapping(0u8); MEM_SIZE as usize],
     };
 
     // SAFETY: `Code` can only be produced by the `crate::codegen` module, which is trusted to not
@@ -44,8 +44,8 @@ impl<'c, W: Write, R: Read> Interpreter<'c, W, R> {
             // SAFETY: If the code ends with an `End` and there are no out of bounds jumps,
             // `self.ip` will never be out of bounds
             // Removing this bounds check speeds up execution by about 40%
-            debug_assert!(self.ip < stmts.len());
-            let instr = unsafe { *stmts.get_unchecked(self.ip) };
+            debug_assert!((self.ip as usize) < stmts.len());
+            let instr = unsafe { *stmts.get_unchecked(self.ip as usize) };
             self.ip += 1;
             match instr {
                 Stmt::Add(n) => {
@@ -97,10 +97,10 @@ impl<'c, W: Write, R: Read> Interpreter<'c, W, R> {
     }
 
     fn elem_mut(&mut self) -> &mut Wrapping<u8> {
-        &mut self.mem[self.ptr]
+        &mut self.mem[self.ptr as usize]
     }
 
     fn elem(&self) -> u8 {
-        self.mem[self.ptr].0
+        self.mem[self.ptr as usize].0
     }
 }