diff --git a/Cargo.lock b/Cargo.lock
index 9065268..0e43ace 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2,6 +2,115 @@
 # It is not intended for manual editing.
 version = 4
 
+[[package]]
+name = "arrayvec"
+version = "0.7.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7c02d123df017efcdfbd739ef81735b36c5ba83ec3c59c80a9d7ecc718f92e50"
+
+[[package]]
+name = "bitcode"
+version = "0.6.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0a6ed1b54d8dc333e7be604d00fa9262f4635485ffea923647b6521a5fff045d"
+dependencies = [
+ "arrayvec",
+ "bitcode_derive",
+ "bytemuck",
+ "glam",
+ "serde",
+]
+
+[[package]]
+name = "bitcode_derive"
+version = "0.6.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "238b90427dfad9da4a9abd60f3ec1cdee6b80454bde49ed37f1781dd8e9dc7f9"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "bytemuck"
+version = "1.25.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c8efb64bd706a16a1bdde310ae86b351e4d21550d98d056f22f8a7f7a2183fec"
+
+[[package]]
+name = "glam"
+version = "0.33.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "898f5a568a84989b6c0f8caa50a93074b97dbdc58fc6d9543157bb4562758933"
+
 [[package]]
 name = "lang"
 version = "0.1.0"
+dependencies = [
+ "bitcode",
+]
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.106"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8fd00f0bb2e90d81d1044c2b32617f68fcb9fa3bb7640c23e9c748e53fb30934"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.45"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "41f2619966050689382d2b44f664f4bc593e129785a36d6ee376ddf37259b924"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "serde"
+version = "1.0.228"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9a8e94ea7f378bd32cbbd37198a4a91436180c5bb472411e48b5ec2e2124ae9e"
+dependencies = [
+ "serde_core",
+]
+
+[[package]]
+name = "serde_core"
+version = "1.0.228"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "41d385c7d4ca58e59fc732af25c3983b67ac852c1a25000afe1175de458b67ad"
+dependencies = [
+ "serde_derive",
+]
+
+[[package]]
+name = "serde_derive"
+version = "1.0.228"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d540f220d3187173da220f885ab66608367b6574e925011a9353e4badda91d79"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "syn"
+version = "2.0.117"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e665b8803e7b1d2a727f4023456bbbbe74da67099c585258af0ad9c5013b9b99"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "unicode-ident"
+version = "1.0.24"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e6e4313cd5fcd3dad5cafa179702e2b244f760991f45397d14d4ebf38247da75"
diff --git a/Cargo.toml b/Cargo.toml
index 3760968..811604c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -4,3 +4,6 @@ version = "0.1.0"
 edition = "2024"
 
 [dependencies]
+
+[dev-dependencies]
+bitcode = "0.6.9"
diff --git a/src/arch/x86_64/test/bin.rs b/src/arch/x86_64/test/bin.rs
index 3606303..dc18d04 100644
--- a/src/arch/x86_64/test/bin.rs
+++ b/src/arch/x86_64/test/bin.rs
@@ -48,7 +48,7 @@ fn linux() -> Result<(), CompilerMsg> {
     program.entry = Some(entry);
     let linked = program.compile().expect("failed to compile");
     let binary = linked.to_elf();
-    let path = "./x86_64_test";
+    let path = "./test/x86_64_test";
     write(path, &binary);
     println!("running...");
     let gdb = false;
@@ -106,7 +106,7 @@ fn windows() -> Result<(), CompilerMsg> {
     let linked = program.compile().expect("failed to compile");
 
     let binary = linked.to_pe();
-    let path = "./x86_64_test.exe";
+    let path = "./test/x86_64_test.exe";
     write(path, &binary);
 
     let mut cmd = Command::new("wine");
diff --git a/src/arch/x86_64/test/nasm.rs b/src/arch/x86_64/test/nasm.rs
index 3d57725..92840b7 100644
--- a/src/arch/x86_64/test/nasm.rs
+++ b/src/arch/x86_64/test/nasm.rs
@@ -1,5 +1,5 @@
 use crate::arch::x86_64::*;
-use std::{fs::OpenOptions, io::Write, process::Command};
+use std::{collections::HashMap, fs::OpenOptions, io::Write, process::Command};
 
 const DISPS: &[i32] = &[
     0x0,
@@ -34,7 +34,8 @@ const WIDTHS: &[Width] = &[Width::B8, Width::B16, Width::B32, Width::B64];
 
 #[test]
 fn mov() {
-    let c = &mut Code::default();
+    let c = &mut TestCtx::new();
+
     for &r1 in Reg::IMPORTANT {
         for &r2 in Reg::IMPORTANT {
             eq(c, format!("mov {r1}, {r2}"), |c| c.mov(r1, r2));
@@ -59,13 +60,27 @@ fn mov() {
     }
 }
 
+struct TestCtx {
+    code: Code,
+    cache: HashMap<String, Result<Vec<u8>, String>>,
+    changed: bool,
+}
+
 fn eq(
-    code: &mut Code,
+    ctx: &mut TestCtx,
     asm: impl AsRef<str>,
     instr: impl FnOnce(&mut Code) -> Result<(), CompilerMsg>,
 ) {
     let asm = asm.as_ref();
-    let expected = nasm(asm);
+    let expected = if let Some(val) = ctx.cache.get(asm) {
+        val
+    } else {
+        ctx.changed = true;
+        let res = nasm(asm);
+        ctx.cache.insert(asm.to_string(), res);
+        ctx.cache.get(asm).unwrap()
+    };
+    let code = &mut ctx.code;
     let res = instr(code);
     match (expected, res) {
         (Ok(expected), Err(e)) => {
@@ -129,3 +144,27 @@ fn write(path: &str, binary: &[u8]) {
     file.write_all(binary).expect("Failed to write to file");
     file.sync_all().expect("Failed to sync file");
 }
+
+const CACHE_PATH: &str = "test/nasm_test_cache";
+
+impl TestCtx {
+    fn new() -> Self {
+        let cache = match std::fs::read(CACHE_PATH) {
+            Ok(bytes) => bitcode::decode(&bytes).unwrap_or_default(),
+            Err(_) => Default::default(),
+        };
+        Self {
+            code: Default::default(),
+            cache,
+            changed: Default::default(),
+        }
+    }
+}
+
+impl Drop for TestCtx {
+    fn drop(&mut self) {
+        if self.changed {
+            write(CACHE_PATH, &bitcode::encode(&self.cache));
+        }
+    }
+}
diff --git a/test/nasm_test_cache b/test/nasm_test_cache
new file mode 100644
index 0000000..48944ce
Binary files /dev/null and b/test/nasm_test_cache differ
diff --git a/test/x86_64_test b/test/x86_64_test
new file mode 100755
index 0000000..f306b2c
Binary files /dev/null and b/test/x86_64_test differ
diff --git a/x86_64_test.exe b/test/x86_64_test.exe
similarity index 100%
rename from x86_64_test.exe
rename to test/x86_64_test.exe
diff --git a/x86_64_test b/x86_64_test
deleted file mode 100755
index 5ce75c5..0000000
Binary files a/x86_64_test and /dev/null differ