read is getting there...

hs/Decode.hs

@@ -1,7 +1,7 @@
 {-# LANGUAGE DataKinds #-}
 {-# LANGUAGE NumericUnderscores #-}
 
-module Decode(decode, DecodeResult) where
+module Decode(decode, DecodeResult(..)) where
 
 import DecodeTypes(
   RTypeFields(..), ITypeFields(..), STypeFields(..),

hs/Read.hs

@@ -10,25 +10,57 @@ import DecodeTypes(
 
     )
 import Clash.Prelude
-import Decode(DecodeResult)
--- import Types(DoubleWord, RegFileIdx, Addr)
+import Decode(DecodeResult(..))
+import Cpu(RISCVCPU(..))
+import RegFiles (RegVal(..), GPR)
 
+read :: DecodeResult -> RISCVCPU -> DecodeResult
+read (Opcode opc) riscvCPU =
+  case opc of
+    ADD fields -> Opcode (ADD (readRTypeFields fields (gpr riscvCPU)))
+    SUB fields -> Opcode (SUB (readRTypeFields fields (gpr riscvCPU)))
+    XOR fields -> Opcode (XOR (readRTypeFields fields (gpr riscvCPU)))
+    OR  fields -> Opcode (OR  (readRTypeFields fields (gpr riscvCPU)))
+    AND fields -> Opcode (AND (readRTypeFields fields (gpr riscvCPU)))
+    SLL fields -> Opcode (SLL (readRTypeFields fields (gpr riscvCPU)))
+    SRL fields -> Opcode (SRL (readRTypeFields fields (gpr riscvCPU)))
+    SRA fields -> Opcode (SRA (readRTypeFields fields (gpr riscvCPU)))
+    SLT fields -> Opcode (SLT (readRTypeFields fields (gpr riscvCPU)))
+    SLTU fields -> Opcode (SLTU (readRTypeFields fields (gpr riscvCPU)))
+    _ -> undefined
+read (DecodeException e) _ = DecodeException e
+read (InstructionException e) _ = InstructionException e
 
--- data SRC = GPR RegVal
---          | FPR RegVal
---          | CSR RegVal
---          | PC  Addr
---          deriving (Generic, Show, Eq, NFDataX)
+readRTypeFields :: RTypeFields -> GPR -> RTypeFields
+readRTypeFields (RTypeFields rd funct3 rs1 rs2 funct7) gprRegFile =
+  let rs1_val = fetchRegVal rs1 gprRegFile
+      rs2_val = fetchRegVal rs2 gprRegFile
+  in RTypeFields rd funct3 rs1_val rs2_val funct7
 
--- data ReadResult = ReadResult
---   { src1 :: SRC,
---     src2 :: SRC,
---     src3 :: SRC
---   }
---   deriving (Generic, Show, Eq, NFDataX)
+readITypeFields :: ITypeFields -> GPR -> ITypeFields
+readITypeFields (ITypeFields rd funct3 rs1 imm) gpr =
+  let rs1_val = fetchRegVal rs1 gpr
+  in ITypeFields rd funct3 rs1_val imm
 
-read = 2
+readSTypeFields :: STypeFields -> GPR -> STypeFields
+readSTypeFields (STypeFields funct3 rs1 rs2 imm12) gpr =
+  let rs1_val = fetchRegVal rs1 gpr
+      rs2_val = fetchRegVal rs2 gpr
+  in STypeFields funct3 rs1_val rs2_val imm12
 
--- opcodeToReadResult :: Opcode -> ReadResult
--- opcodeToReadResult (ADD (RTypeFields _ rd funct3 rs1 rs2 funct7)) = undefined
--- opcodeToReadResult _ = undefined
+readBTypeFields :: BTypeFields -> GPR -> BTypeFields
+readBTypeFields (BTypeFields funct3 rs1 rs2 imm13) gpr =
+  let rs1_val = fetchRegVal rs1 gpr
+      rs2_val = fetchRegVal rs2 gpr
+  in BTypeFields funct3 rs1_val rs2_val imm13
+
+readUTypeFields :: UTypeFields -> GPR -> UTypeFields
+readUTypeFields fields@(UTypeFields rd imm20) _ = fields
+
+readJTypeFields :: JTypeFields -> GPR -> JTypeFields
+readJTypeFields fields@(JTypeFields rd imm21) _ = fields
+
+-- Helper function to fetch register value
+fetchRegVal :: RegVal -> GPR -> RegVal
+fetchRegVal (Unpopulated idx) gprVal = Value idx (gprVal !! idx)
+fetchRegVal val@(Value _ _) _ = val  -- Already populated, no change