add rcmp instr, add rot13 example

crsn_arith/src/defs.rs

@@ -5,6 +5,7 @@ use crsn::asm::data::{Rd, Wr};
 pub enum ArithOp {
     Test { a: Rd },
     Compare { a: Rd, b: Rd },
+    RangeTest { val: Rd, a: Rd, b: Rd },
 
     Add { dst: Wr, a: Rd, b: Rd },
     Sub { dst: Wr, a: Rd, b: Rd },

crsn_arith/src/exec.rs

@@ -34,6 +34,16 @@ impl OpTrait for ArithOp {
                     state.update_status(x);
                 }
             }
+            ArithOp::RangeTest { val, a, b } => {
+                state.clear_status();
+                let val = state.read(*val)?;
+                let a = state.read(*a)?;
+                let b = state.read(*b)?;
+                state.set_flag(Cond::Equal, val >= a && val <= b);
+                state.set_flag(Cond::Lower, val < a);
+                state.set_flag(Cond::Greater, val > b);
+                state.update_status(val);
+            }
             ArithOp::Add { dst, a, b } => {
                 state.clear_status();
                 let x = state.read(*a)?;
@@ -201,6 +211,7 @@ impl OpTrait for ArithOp {
             ArithOp::Add { dst, a, b } => to_sexp_2_or_3("add", dst, a, b),
             ArithOp::Test { a } => sexp::list(&[A("test"), A(a)]),
             ArithOp::Compare { a, b } => sexp::list(&[A("cmp"), A(a), A(b)]),
+            ArithOp::RangeTest { val, a: start, b: end } => sexp::list(&[A("rcmp"), A(val), A(start), A(end)]),
             ArithOp::Sub { dst, a, b } => to_sexp_2_or_3("sub", dst, a, b),
             ArithOp::Mul { dst, a, b } => to_sexp_2_or_3("mul", dst, a, b),
             ArithOp::Div { dst, rem, a, div } => {

crsn_arith/src/parse.rs

@@ -16,6 +16,14 @@ pub(crate) fn parse<'a>(pos: &SourcePosition, keyword: &str, mut args: TokenPars
             }
         }
 
+        "rcmp" => {
+            ArithOp::RangeTest {
+                val: args.next_rd()?,
+                a: args.next_rd()?,
+                b: args.next_rd()?,
+            }
+        }
+
         "tst" => {
             let arg = args.next_rd()?;
             ArithOp::Test { a: arg }