Add copy_special instruction.

lib/cretonne/src/ir/instructions.rs

@@ -236,6 +236,11 @@ pub enum InstructionData {
         src: RegUnit,
         dst: RegUnit,
     },
+    CopySpecial {
+        opcode: Opcode,
+        src: RegUnit,
+        dst: RegUnit,
+    },
     RegSpill {
         opcode: Opcode,
         arg: Value,

lib/cretonne/src/verifier/mod.rs

@@ -358,6 +358,7 @@ impl<'a> Verifier<'a> {
             Load { .. } |
             Store { .. } |
             RegMove { .. } |
+            CopySpecial { .. } |
             Trap { .. } |
             CondTrap { .. } |
             NullAry { .. } => {}

lib/cretonne/src/write.rs

@@ -394,6 +394,19 @@ pub fn write_operands(
                 write!(w, " {}, %{} -> %{}", arg, src, dst)
             }
         }
+        CopySpecial { src, dst, .. } => {
+            if let Some(isa) = isa {
+                let regs = isa.register_info();
+                write!(
+                    w,
+                    " {} -> {}",
+                    regs.display_regunit(src),
+                    regs.display_regunit(dst)
+                )
+            } else {
+                write!(w, " %{} -> %{}", src, dst)
+            }
+        }
         RegSpill { arg, src, dst, .. } => {
             if let Some(isa) = isa {
                 let regs = isa.register_info();