1 files changed, 16 insertions, 32 deletions

diff --git a/src/real_mode/mod.rs b/src/real_mode/mod.rs
index 2530c1d..6c7365c 100644
--- a/src/real_mode/mod.rs
+++ b/src/real_mode/mod.rs
@@ -133,10 +133,8 @@ impl RegSpec {
 
     /// construct a `RegSpec` for x87 register `st(num)`
     #[inline]
-    pub fn st(num: u8) -> RegSpec {
-        if num >= 8 {
-            panic!("invalid x87 reg st({})", num);
-        }
+    pub const fn st(num: u8) -> RegSpec {
+        assert!(num < 8, "invalid x87 reg");
 
         RegSpec {
             num,
@@ -146,10 +144,8 @@ impl RegSpec {
 
     /// construct a `RegSpec` for xmm reg `num`
     #[inline]
-    pub fn xmm(num: u8) -> RegSpec {
-        if num >= 32 {
-            panic!("invalid x86 xmm reg {}", num);
-        }
+    pub const fn xmm(num: u8) -> RegSpec {
+        assert!(num < 32, "invalid x86 xmm reg");
 
         RegSpec {
             num,
@@ -159,10 +155,8 @@ impl RegSpec {
 
     /// construct a `RegSpec` for ymm reg `num`
     #[inline]
-    pub fn ymm(num: u8) -> RegSpec {
-        if num >= 32 {
-            panic!("invalid x86 ymm reg {}", num);
-        }
+    pub const fn ymm(num: u8) -> RegSpec {
+        assert!(num < 32, "invalid x86 ymm reg");
 
         RegSpec {
             num,
@@ -172,10 +166,8 @@ impl RegSpec {
 
     /// construct a `RegSpec` for zmm reg `num`
     #[inline]
-    pub fn zmm(num: u8) -> RegSpec {
-        if num >= 32 {
-            panic!("invalid x86 zmm reg {}", num);
-        }
+    pub const fn zmm(num: u8) -> RegSpec {
+        assert!(num < 32, "invalid x86 zmm reg");
 
         RegSpec {
             num,
@@ -185,10 +177,8 @@ impl RegSpec {
 
     /// construct a `RegSpec` for mask reg `num`
     #[inline]
-    pub fn mask(num: u8) -> RegSpec {
-        if num >= 8 {
-            panic!("invalid x86 mask reg {}", num);
-        }
+    pub const fn mask(num: u8) -> RegSpec {
+        assert!(num < 8, "invalid x86 mask reg");
 
         RegSpec {
             num,
@@ -198,10 +188,8 @@ impl RegSpec {
 
     /// construct a `RegSpec` for dword reg `num`
     #[inline]
-    pub fn d(num: u8) -> RegSpec {
-        if num >= 8 {
-            panic!("invalid x86 dword reg {}", num);
-        }
+    pub const fn d(num: u8) -> RegSpec {
+        assert!(num < 8, "invalid x86 dword reg");
 
         RegSpec {
             num,
@@ -211,10 +199,8 @@ impl RegSpec {
 
     /// construct a `RegSpec` for word reg `num`
     #[inline]
-    pub fn w(num: u8) -> RegSpec {
-        if num >= 8 {
-            panic!("invalid x86 word reg {}", num);
-        }
+    pub const fn w(num: u8) -> RegSpec {
+        assert!(num < 8, "invalid x86 word reg");
 
         RegSpec {
             num,
@@ -224,10 +210,8 @@ impl RegSpec {
 
     /// construct a `RegSpec` for byte reg `num`
     #[inline]
-    pub fn b(num: u8) -> RegSpec {
-        if num >= 8 {
-            panic!("invalid x86 byte reg {}", num);
-        }
+    pub const fn b(num: u8) -> RegSpec {
+        assert!(num < 8, "invalid x86 byte reg");
 
         RegSpec {
             num,