diff --git a/src/arch/x86_64/test/asm/setup.rs b/src/arch/x86_64/test/asm/setup.rs
index 16b3b33..ea58c7f 100644
--- a/src/arch/x86_64/test/asm/setup.rs
+++ b/src/arch/x86_64/test/asm/setup.rs
@@ -63,39 +63,58 @@ pub struct TestCtx {
 pub fn eq(
     ctx: &mut TestCtx,
     asm: impl AsRef<str>,
-    instr: impl FnOnce(&mut Code) -> Result<(), CompilerMsg>,
+    instr: impl Fn(&mut Code) -> Result<(), CompilerMsg>,
 ) {
     let asm = asm.as_ref();
-    let expected = if let Some(val) = ctx.cache.get(asm) {
-        val
+    let (mut res, cache) = eq_(ctx, asm, &instr);
+    if res.is_err() && cache {
+        ctx.cache.remove(asm);
+        res = eq_(ctx, asm, &instr).0;
+    }
+    if let Err(err) = res {
+        panic!("{err}");
+    }
+}
+
+#[track_caller]
+pub fn eq_(
+    ctx: &mut TestCtx,
+    asm: &str,
+    instr: impl FnOnce(&mut Code) -> Result<(), CompilerMsg>,
+) -> (Result<(), String>, bool) {
+    let (expected, cache) = if let Some(val) = ctx.cache.get(asm) {
+        (val, true)
     } else {
         ctx.changed = true;
         let res = nasm(asm);
         ctx.cache.insert(asm.to_string(), res);
-        ctx.cache.get(asm).unwrap()
+        (ctx.cache.get(asm).unwrap(), false)
     };
     let code = &mut ctx.code;
     let res = instr(code);
-    match (expected, res) {
-        (Ok(expected), Err(e)) => {
-            panic!(
-                "{asm}: failed to compile: {}\nexpected: {expected:x?}",
-                e.msg
-            );
-        }
+    let res = match (expected, res) {
+        (Ok(expected), Err(e)) => Err(format!(
+            "{asm}: failed to compile: {}\nexpected: {expected:x?}",
+            e.msg
+        )),
         (Err(e), Ok(_)) => {
             let res = &code.bytes[..];
-            panic!("{asm}: should not have compiled:\n{e}\ngot: {res:x?}");
+            Err(format!(
+                "{asm}: should not have compiled:\n{e}\ngot: {res:x?}"
+            ))
         }
-        (Err(_), Err(_)) => (),
+        (Err(_), Err(_)) => Ok(()),
         (Ok(expected), Ok(_)) => {
             let res = &code.bytes[..];
             if expected != res {
-                panic!("{asm}: expected {expected:x?}, got {res:x?}")
+                Err(format!("{asm}: expected {expected:x?}, got {res:x?}"))
+            } else {
+                Ok(())
             }
         }
-    }
-    code.bytes.clear();
+    };
+    ctx.code.bytes.clear();
+    (res, cache)
 }
 
 fn nasm(input: &str) -> Result<Vec<u8>, String> {
@@ -103,7 +122,7 @@ fn nasm(input: &str) -> Result<Vec<u8>, String> {
     let fout = "/tmp/69420nasm_out.o";
     let input = "result:".to_string() + input;
     write(fin, input.as_bytes());
-    run(["nasm", "-O1", "-w+error", "-felf64", fin, &format!("-o{fout}")])?;
+    run(["nasm", "-w+error", "-felf64", fin, &format!("-o{fout}")])?;
     let output = run(["objdump", "--no-addresses", "-dw", "-Mintel", fout])?;
     let mut iter = output.lines().skip_while(|l| !l.contains("result")).skip(1);
     let res_line = iter.next().unwrap().trim();
diff --git a/src/arch/x86_64/types/reg.rs b/src/arch/x86_64/types/reg.rs
index 7650f09..b7f5654 100644
--- a/src/arch/x86_64/types/reg.rs
+++ b/src/arch/x86_64/types/reg.rs
@@ -14,7 +14,7 @@ def_regs! {
     0b0011 : rbx ebx bx bl,
 
     0b0100 : rsp esp sp spl norex=ah !_,
-    0b0101 : rbp ebp bp bpl norex=ch,
+    0b0101 : rbp ebp bp bpl norex=ch !_,
     0b0110 : rsi esi si sil norex=dh !_,
     0b0111 : rdi edi di dil norex=bh,
 
diff --git a/test/nasm_cache/add_sub b/test/nasm_cache/add_sub
index 139242f..ff1d62d 100644
Binary files a/test/nasm_cache/add_sub and b/test/nasm_cache/add_sub differ
diff --git a/test/nasm_cache/mov b/test/nasm_cache/mov
index d7f6e9d..55d6cf9 100644
Binary files a/test/nasm_cache/mov and b/test/nasm_cache/mov differ