Major performance improvements

src/bin/bench/main.rs

@@ -0,0 +1,47 @@
+use std::{path::PathBuf, time::Instant};
+
+use nes_emu::{Break, NES};
+use tracing_subscriber::EnvFilter;
+use clap::Parser;
+
+extern crate nes_emu;
+
+#[derive(Parser)]
+#[command(version, about)]
+struct Args {
+    file: PathBuf,
+    #[arg(short, long)]
+    frames: Option<usize>,
+}
+
+fn main() -> Result<(), anyhow::Error> {
+    tracing_subscriber::fmt()
+        .with_env_filter(EnvFilter::from_default_env())
+        .init();
+    let args = Args::parse();
+
+    if let Some(frames) = args.frames {
+        println!("Running {frames} frames of {} as fast as possible", args.file.display());
+    } else {
+        println!("Running {} as fast as possible", args.file.display());
+    }
+    let mut n = NES::load_nes_file(args.file).unwrap();
+    n.reset();
+
+    let start = Instant::now();
+    let mut cur = 0;
+    loop {
+        while !n.halted() && !n.run_one_clock_cycle(&Break::default()).ppu_frame {
+        }
+        n.apu_mut().reset_frame_samples();
+        cur += 1;
+        if args.frames.is_some_and(|f| f < cur) {
+            let time = start.elapsed();
+            println!("Completed {} in {}s", cur, time.as_secs_f64());
+            println!("~= {} fps", cur as f64 / time.as_secs_f64());
+            break Ok(());
+        }
+        // TODO: update currently held button in controller
+    }
+    // Ok(())
+}