From 04036bb047f99ed75e4a2804616ffe84bb49c7d1 Mon Sep 17 00:00:00 2001
From: Joscha <joscha@plugh.de>
Date: Wed, 6 Nov 2019 14:17:32 +0000
Subject: [PATCH] Add LDIV, STIV instructions

---
 src/Mima/Instruction.hs |  6 ++++--
 src/Mima/State.hs       | 28 ++++++++++++++++++----------
 2 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/src/Mima/Instruction.hs b/src/Mima/Instruction.hs
index f3f4197..37d515d 100644
--- a/src/Mima/Instruction.hs
+++ b/src/Mima/Instruction.hs
@@ -14,14 +14,14 @@ import           Data.Word
 import           Mima.Util
 import           Mima.Word
 
-data SmallOpcode = LDC | LDV | STV | ADD | AND | OR | XOR | EQL | JMP | JMN
+data SmallOpcode = LDC | LDV | STV | ADD | AND | OR | XOR | EQL | JMP | JMN | STIV | LDIV
   deriving (Show, Eq, Ord)
 
 instance ToText SmallOpcode where
   toText = T.pack . show
 
 allSmallOpcodes :: [SmallOpcode]
-allSmallOpcodes = [LDC, LDV, STV, ADD, AND, OR, XOR, EQL, JMP, JMN]
+allSmallOpcodes = [LDC, LDV, STV, ADD, AND, OR, XOR, EQL, JMP, JMN, STIV, LDIV]
 
 getSmallOpcode :: SmallOpcode -> Word32
 getSmallOpcode LDC = 0
@@ -34,6 +34,8 @@ getSmallOpcode XOR = 6
 getSmallOpcode EQL = 7
 getSmallOpcode JMP = 8
 getSmallOpcode JMN = 9
+getSmallOpcode STIV = 10
+getSmallOpcode LDIV = 11
 
 smallOpcodeMap :: Map.Map Word32 SmallOpcode
 smallOpcodeMap = Map.fromList [(getSmallOpcode oc, oc) | oc <- allSmallOpcodes]
diff --git a/src/Mima/State.hs b/src/Mima/State.hs
index 10283b4..c08854f 100644
--- a/src/Mima/State.hs
+++ b/src/Mima/State.hs
@@ -81,16 +81,24 @@ step ms = do
     (LargeInstruction oc)           -> executeLargeOpcode oc ms
 
 executeSmallOpcode :: SmallOpcode -> MimaAddress -> MimaState -> Either ExecException MimaState
-executeSmallOpcode LDC addr ms = incrementIp ms{msAcc = addressToWord addr}
-executeSmallOpcode LDV addr ms = incrementIp ms{msAcc = readAt addr (msMemory ms)}
-executeSmallOpcode STV addr ms = incrementIp ms{msMemory = writeAt addr (msAcc ms) (msMemory ms)}
-executeSmallOpcode ADD addr ms = incrementIp ms{msAcc = addWords (msAcc ms) (readAt addr $ msMemory ms)}
-executeSmallOpcode AND addr ms = incrementIp ms{msAcc = msAcc ms .&.   readAt addr (msMemory ms)}
-executeSmallOpcode OR  addr ms = incrementIp ms{msAcc = msAcc ms .|.   readAt addr (msMemory ms)}
-executeSmallOpcode XOR addr ms = incrementIp ms{msAcc = msAcc ms `xor` readAt addr (msMemory ms)}
-executeSmallOpcode EQL addr ms = incrementIp ms{msAcc = boolToWord $ msAcc ms == readAt addr (msMemory ms)}
-executeSmallOpcode JMP addr ms = pure ms{msIp = addr}
-executeSmallOpcode JMN addr ms = if topBit (msAcc ms) then pure ms{msIp = addr} else incrementIp ms
+executeSmallOpcode LDC  addr ms = incrementIp ms{msAcc = addressToWord addr}
+executeSmallOpcode LDV  addr ms = incrementIp ms{msAcc = readAt addr (msMemory ms)}
+executeSmallOpcode STV  addr ms = incrementIp ms{msMemory = writeAt addr (msAcc ms) (msMemory ms)}
+executeSmallOpcode ADD  addr ms = incrementIp ms{msAcc = addWords (msAcc ms) (readAt addr $ msMemory ms)}
+executeSmallOpcode AND  addr ms = incrementIp ms{msAcc = msAcc ms .&.   readAt addr (msMemory ms)}
+executeSmallOpcode OR   addr ms = incrementIp ms{msAcc = msAcc ms .|.   readAt addr (msMemory ms)}
+executeSmallOpcode XOR  addr ms = incrementIp ms{msAcc = msAcc ms `xor` readAt addr (msMemory ms)}
+executeSmallOpcode EQL  addr ms = incrementIp ms{msAcc = boolToWord $ msAcc ms == readAt addr (msMemory ms)}
+executeSmallOpcode JMP  addr ms = pure ms{msIp = addr}
+executeSmallOpcode JMN  addr ms = if topBit (msAcc ms) then pure ms{msIp = addr} else incrementIp ms
+executeSmallOpcode STIV addr ms =
+  let mem = msMemory ms
+      indirAddr = address $ readAt addr mem
+  in  incrementIp ms{msMemory = writeAt indirAddr (msAcc ms) mem}
+executeSmallOpcode LDIV addr ms =
+  let mem = msMemory ms
+      indirAddr = address $ readAt addr mem
+  in  incrementIp ms{msAcc = readAt indirAddr mem}
 
 executeLargeOpcode :: LargeOpcode -> MimaState -> Either ExecException MimaState
 executeLargeOpcode HALT ms =