From 5487fb66a2eba979af4e58f49c77c84795c9a38d Mon Sep 17 00:00:00 2001
From: Reid 'arrdem' McKenzie <me@arrdem.com>
Date: Mon, 2 Jan 2023 23:12:06 -0700
Subject: [PATCH] Add jump-immediate extension to the ISA

---
 src/isa.rs | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/src/isa.rs b/src/isa.rs
index 3576e5f..a24c4ff 100644
--- a/src/isa.rs
+++ b/src/isa.rs
@@ -4,8 +4,16 @@ pub struct Icode {}
 impl Icode {
     // Official names
     pub const BRK: u8 = 0x00u8;
-    pub const LIT: u8 = 0b10000000; // AKA keep Yes really. Per spec;
-    pub const LIT2: u8 = 0b10100000; // AKA keep Yes really. Per spec;
+
+    // LIT is BRK + flags
+    pub const LIT: u8 = 0x80; // AKA keep Yes really. Per spec;
+    pub const LIT2: u8 = 0xa0; // AKA keep Yes really. Per spec;
+
+    // Jump-immediate extensions (again BRK + flags)
+    pub const JMI: u8 = 0x20; // Jump [to] immediate
+    pub const JCI: u8 = 0x40; // Jump Conditional Immediate
+    pub const JSI: u8 = 0x60; // Jump Storing Immediate (call)
+
     pub const INC: u8 = 0x01;
     pub const POP: u8 = 0x02;
     pub const NIP: u8 = 0x03;
@@ -63,7 +71,7 @@ impl Icode {
     pub const fn nameof(opcode: u8) -> &'static str {
         match opcode {
             // Nonstandard icodes + extensions
-            Icode::LIT | Icode::LIT2 => "LIT", // AKA keep Yes really. Per spec,
+            Icode::LIT | Icode::LIT2 => "LIT", // AKA keep. Yes really. Per spec,
             Icode::NOP => "NOP",
             // Standard icodes
             Icode::BRK => "BRK",
@@ -98,6 +106,10 @@ impl Icode {
             Icode::ORA => "ORA",
             Icode::EOR => "EOR",
             Icode::SFT => "SFT",
+            // Jump immediate extension
+            Icode::JMI => "JMI",
+            Icode::JCI => "JCI",
+            Icode::JSI => "JSI",
             _ => Icode::nameof(opcode & 0x1F),
         }
     }