Add ADD, DEC, TEST, RET instructions

7 files changed, 67 insertions, 3 deletions

diff --git a/src/insn.rs b/src/insn.rs
index c0bcc4e..2bfaf18 100644
--- a/src/insn.rs
+++ b/src/insn.rs
@@ -1,5 +1,21 @@
+mod add;
+mod dec;
 mod mov;
+mod ret;
+mod test;
+
+pub trait Add<T, U> {
+    fn add(&mut self, op1: T, op2: U);
+}
+
+pub trait Dec<T> {
+    fn dec(&mut self, op1: T);
+}
 
 pub trait Mov<T, U> {
     fn mov(&mut self, op1: T, op2: U);
 }
+
+pub trait Test<T, U> {
+    fn test(&mut self, op1: T, op2: U);
+}
diff --git a/src/insn/add.rs b/src/insn/add.rs
new file mode 100644
index 0000000..b8456c4
--- /dev/null
+++ b/src/insn/add.rs
@@ -0,0 +1,7 @@
+use crate::prelude::*;
+
+impl Add<Reg64, Reg64> for Asm {
+    fn add(&mut self, op1: Reg64, op2: Reg64) {
+        self.encode_rr(0x01, op1, op2);
+    }
+}
diff --git a/src/insn/dec.rs b/src/insn/dec.rs
new file mode 100644
index 0000000..7de5a54
--- /dev/null
+++ b/src/insn/dec.rs
@@ -0,0 +1,7 @@
+use crate::prelude::*;
+
+impl Dec<Reg64> for Asm {
+    fn dec(&mut self, op1: Reg64) {
+        self.encode_r(0xff, 1, op1);
+    }
+}
diff --git a/src/insn/ret.rs b/src/insn/ret.rs
new file mode 100644
index 0000000..74086d8
--- /dev/null
+++ b/src/insn/ret.rs
@@ -0,0 +1,7 @@
+use crate::Asm;
+
+impl Asm {
+    pub fn ret(&mut self) {
+        self.emit(&[0xc3]);
+    }
+}
diff --git a/src/insn/test.rs b/src/insn/test.rs
new file mode 100644
index 0000000..1319e3f
--- /dev/null
+++ b/src/insn/test.rs
@@ -0,0 +1,7 @@
+use crate::prelude::*;
+
+impl Test<Reg64, Reg64> for Asm {
+    fn test(&mut self, op1: Reg64, op2: Reg64) {
+        self.encode_rr(0x85, op1, op2);
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
index e38da14..27164ad 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -107,8 +107,8 @@ impl Asm {
         Self: EncodeRI<T>,
     {
         // MI operand encoding.
-        //   op1 -> modrm.rm
-        //   op2 -> modrm.reg
+        //   op1           -> modrm.rm
+        //   opc extension -> modrm.reg
         let modrm = modrm(
             0b11,      /* mod */
             opc_ext,   /* reg */
@@ -123,6 +123,26 @@ impl Asm {
         self.emit(op2.bytes());
     }
 
+    fn encode_r<T: Reg>(&mut self, opc: u8, opc_ext: u8, op1: T)
+    where
+        Self: EncodeRI<T>,
+    {
+        // M operand encoding.
+        //   op1           -> modrm.rm
+        //   opc extension -> modrm.reg
+        let modrm = modrm(
+            0b11,      /* mod */
+            opc_ext,   /* reg */
+            op1.idx(), /* rm */
+        );
+
+        let prefix = <Self as EncodeRI<T>>::legacy_prefix();
+        let rex = <Self as EncodeRI<T>>::rex(op1);
+
+        self.emit_optional(&[prefix, rex]);
+        self.emit(&[opc, modrm]);
+    }
+
     fn encode_mr<T: Reg>(&mut self, opc: u8, op1: MemOp, op2: T)
     where
         Self: EncodeMR<T>,
diff --git a/src/prelude.rs b/src/prelude.rs
index d1cd794..bca972f 100644
--- a/src/prelude.rs
+++ b/src/prelude.rs
@@ -3,4 +3,4 @@ pub use crate::MemOp;
 pub use crate::{Imm16, Imm32, Imm64, Imm8};
 pub use crate::{Reg16, Reg32, Reg64, Reg8};
 
-pub use crate::insn::{Add, Mov};
+pub use crate::insn::{Add, Dec, Mov, Test};